PNC MORTGAGE SECURITIES CORP
424B5, 1997-04-29
FINANCE SERVICES
Previous: PNC MORTGAGE SECURITIES CORP, 8-K, 1997-04-29
Next: JONES EDWARD D & CO DAILY PASSPORT CASH TRUST, NSAR-B, 1997-04-29



<PAGE>
PROSPECTUS SUPPLEMENT
(TO PROSPECTUS DATED NOVEMBER 21, 1996)
                                  PNC MORTGAGE
                                SECURITIES CORP.
                         DEPOSITOR AND MASTER SERVICER
               MORTGAGE PASS-THROUGH CERTIFICATES, SERIES 1997-3
 
                                  $446,638,440
                                 (APPROXIMATE)
PRINCIPAL AND/OR INTEREST PAYABLE ON THE 25TH DAY OF EACH MONTH BEGINNING IN MAY
                                      1997
 
THESE CERTIFICATES DO NOT REPRESENT AN OBLIGATION OF OR INTEREST IN PNC MORTGAGE
      SECURITIES CORP. OR ANY OF ITS AFFILIATES, INCLUDING PNC BANK CORP.
     NEITHER THESE CERTIFICATES NOR THE UNDERLYING MORTGAGE LOANS ARE
               GUARANTEED BY ANY AGENCY OR INSTRUMENTALITY OF THE
                               UNITED STATES.
 
    The Mortgage Pass-Through Certificates, Series 1997-3 (the "Certificates"),
will consist of the following thirty-one classes: (i) Class IA-1, Class IA-2,
Class IA-3, Class IA-4, Class IA-5, Class IA-6 and Class IA-7 (the "Group IA
Certificates"), (ii) Class IIA-1, Class IIA-2, Class IIA-3, Class IIA-4, Class
IIA-5, Class IIA-6 and Class IIA-7 (the "Group IIA Certificates" and, together
with the Group IA Certificates, the "Class A Certificates"), (iii) Class IP,
(iv) Class IX-1 and Class IX-2 (the "Class IX Certificates") and Class IIX
(together with the Class IX Certificates, the "Class X Certificates"), (v) Class
IB-1, Class IB-2 and Class IB-3 (the "Group I Senior Subordinate Certificates"),
(vi) Class IB-4, Class IB-5 and Class IB-6 (the "Group I Junior Subordinate
Certificates" and, together with the Group I Senior Subordinate Certificates,
the "Group IB Certificates"), (vii) Class IIB-1, Class IIB-2 and Class IIB-3
(the "Group II Senior Subordinate Certificates"), (viii) Class IIB-4, Class
IIB-5 and Class IIB-6 (the "Group II Junior Subordinate Certificates" and,
together with the Group II Senior Subordinate Certificates, the "Group IIB
Certificates") and (ix) Class R (the "Residual Certificates" and, together with
the Class A, Class X and Class IP Certificates, the "Senior Certificates"). The
Group IA, Class IP, Class IX and Group IB Certificates are sometimes referred to
as the "Group I Certificates" and the Group IIA, Class IIX and Group IIB
Certificates are sometimes referred to as the "Group II Certificates". The Group
I Certificates and the Group II Certificates are each a "Certificate Group". The
Class IA-3 and Class IIA-4 Certificates are sometimes referred to as the
"Lockout Certificates". The Group I Senior Subordinate Certificates and Group II
Senior Subordinate Certificates are collectively referred to as the "Senior
Subordinate Certificates". The Group I Junior Subordinate Certificates and Group
II Junior Subordinate Certificates are collectively referred to as the "Junior
Subordinate Certificates". The Group IB and Group IIB Certificates are
collectively referred to as the "Subordinate Certificates" or "Class B
Certificates". Only the Senior Certificates (other than the Class IIA-1
Certificates) and the Senior Subordinate Certificates (collectively, the
"Offered Certificates") are offered hereby. The Class IIA-1 Certificates and the
Junior Subordinate Certificates are not offered hereby. It is a condition to the
issuance of the Offered Certificates that the Class A Certificates and Class R
Certificates each be rated "AAA" by Standard & Poor's, a division of The
McGraw-Hill Companies, Inc. ("S&P") and by Duff & Phelps Credit Rating Co.
("DCR"), that the Class X and Class IP Certificates each be rated "AAAr" by S&P
and "AAA" by DCR and that the Class IB-1 and Class IIB-1 Certificates be rated
not less than "AA" by DCR, the Class IB-2 and Class IIB-2 Certificates be rated
not less than "A" by DCR and the Class IB-3 and Class IIB-3 Certificates be
rated not less than "BBB" by DCR. See "Certificate Ratings" herein.
 
<TABLE>
<CAPTION>
                                    APPROXIMATE
                                   INITIAL CLASS
                                     PRINCIPAL      REMITTANCE
                                      BALANCE        RATE(1)
<S>                               <C>              <C>
Class IA-1......................    $36,550,361         7.000%(2)
Class IA-2......................     19,784,500         7.000%(3)
Class IA-3......................     31,741,470         7.000%
Class IA-4......................     44,000,000         7.000%
Class IA-5......................      8,820,291         7.000%
Class IA-6......................      4,779,258         7.000%
Class IA-7......................      1,616,275         7.000%(4)
Class IIA-2.....................     28,500,000         7.500%
Class IIA-3.....................    139,910,604         7.500%
Class IIA-4.....................     71,700,000         7.500%
Class IIA-5.....................      6,635,107         7.500%(5)
Class IIA-6.....................     16,000,000         7.500%
</TABLE>
 
<TABLE>
<CAPTION>
                                   APPROXIMATE
                                  INITIAL CLASS
                                    PRINCIPAL      REMITTANCE
                                     BALANCE        RATE(1)
<S>                              <C>              <C>
Class IIA-7....................    $19,587,131         7.500%
Class IX-1.....................             --         7.000%(6)
Class IX-2.....................             --         7.000%(7)
Class IIX......................             --         7.500%(8)
Class IP.......................        129,474           (9)
Class IB-1.....................      2,659,670         7.000%
Class IB-2.....................        379,952         7.000%
Class IB-3.....................        379,952         7.000%
Class IIB-1....................      7,180,984         7.500%
Class IIB-2....................      4,488,115         7.500%
Class IIB-3....................      1,795,246         7.500%
Class R........................             50         7.000%
</TABLE>
 
    The Offered Certificates are being offered by Donaldson, Lufkin & Jenrette
Securities Corporation (the "Underwriter") from time to time in negotiated
transactions or otherwise at varying prices to be determined at the time of
sale. Sales may be made to investors at the same price or at different prices.
See "Method of Distribution" herein. The aggregate proceeds to PNC Mortgage
Securities Corp. (the "Company") from the sale of the Offered Certificates,
before deducting expenses estimated to be $520,000, will be 100.910% of the
initial aggregate Certificate Principal Balance of the Offered Certificates plus
accrued interest. The difference between the aggregate purchase price for the
Offered Certificates paid to the Company and the aggregate proceeds from the
sale of the Offered Certificates realized by the Underwriter will constitute
underwriting discounts and commissions. The Company has agreed to indemnify the
Underwriter against certain liabilities, including liabilities under the
Securities Act of 1933. See "Method of Distribution" herein.
 
    SEE "RISK FACTORS" IMMEDIATELY FOLLOWING "SUMMARY INFORMATION" HEREIN AND
IMMEDIATELY FOLLOWING "SUMMARY OF PROSPECTUS" IN THE PROSPECTUS FOR A DISCUSSION
OF CERTAIN FACTORS THAT SHOULD BE CONSIDERED BEFORE PURCHASING ANY OF THE
OFFERED CERTIFICATES.
                              -------------------
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE NOR HAS ANY
     SUCH COMMISSION PASSED UPON THE ACCURACY OR ADEQUACY OF THIS
        PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL
                                    OFFENSE.
                            ------------------------
    The Offered Certificates are offered by the Underwriter, as specified
herein, subject to receipt and acceptance by it, and subject to its right to
reject any order in whole or in part and to certain other conditions. It is
expected that delivery of the Offered Certificates (other than the Class R,
Senior Subordinate, Class X and Class IP Certificates) will be made through the
facilities of The Depository Trust Company, and that delivery of the Class R
(other than the portion of the Class R Certificates retained by the Company),
Senior Subordinate, Class X and Class IP Certificates will be made at the
offices of the Underwriter, on or about April 30, 1997. (Additional cover page
information is contained on the following four pages.)
 
                          DONALDSON, LUFKIN & JENRETTE
                             SECURITIES CORPORATION
<PAGE>
            THE DATE OF THIS PROSPECTUS SUPPLEMENT IS APRIL 28, 1997
<PAGE>
<PAGE>
(CONTINUED FROM PREVIOUS PAGE)
 
(1) INTEREST DISTRIBUTED TO THE OFFERED CERTIFICATES (OTHER THAN THE CLASS IP
    CERTIFICATES WHICH WILL NOT BE ENTITLED TO RECEIVE DISTRIBUTIONS OF
    INTEREST) ON EACH DISTRIBUTION DATE WILL HAVE ACCRUED DURING THE PRECEDING
    CALENDAR MONTH AT THE APPLICABLE PER ANNUM REMITTANCE RATE.
 
(2) THE CLASS IA-1 CERTIFICATES ARE COMPRISED OF TWO PAYMENT COMPONENTS. THE
    INTEREST AND PRINCIPAL DISTRIBUTABLE TO THE CLASS IA-1 CERTIFICATES WILL BE
    BASED ON THE INTEREST AND PRINCIPAL ALLOCABLE TO EACH COMPONENT THEREOF.
 
(3) THE CLASS IA-2 CERTIFICATES ARE COMPRISED OF TWO PAYMENT COMPONENTS. THE
    INTEREST AND PRINCIPAL DISTRIBUTABLE TO THE CLASS IA-2 CERTIFICATES WILL BE
    BASED ON THE INTEREST AND PRINCIPAL ALLOCABLE TO EACH COMPONENT THEREOF.
 
(4) ON EACH DISTRIBUTION DATE ON OR BEFORE THE CLASS IA-7 ACCRETION TERMINATION
    DATE (AS DEFINED HEREIN), AN AMOUNT EQUAL TO THE CLASS IA-7 ACCRUAL AMOUNT
    (AS DEFINED HEREIN) WILL BE ADDED TO THE CLASS IA-7 PRINCIPAL BALANCE, AND
    SUCH AMOUNT WILL BE DISTRIBUTED AS PRINCIPAL ON THE TAC COMPONENT OF THE
    CLASS IA-2 CERTIFICATES AS DESCRIBED HEREIN.
 
(5) ON EACH DISTRIBUTION DATE ON OR BEFORE THE CLASS IIA-5 ACCRETION TERMINATION
    DATE (AS DEFINED HEREIN), AN AMOUNT EQUAL TO THE CLASS IIA-5 ACCRUAL AMOUNT
    (AS DEFINED HEREIN) WILL BE ADDED TO THE CLASS IIA-5 PRINCIPAL BALANCE, AND
    SUCH AMOUNT WILL BE DISTRIBUTED AS PRINCIPAL ON THE CLASS IIA-3 CERTIFICATES
    AND THE TAC COMPONENT OF THE CLASS IIA-1 CERTIFICATES AS DESCRIBED HEREIN.
 
(6) THE REMITTANCE RATE ON THE CLASS IX-1 CERTIFICATES WILL BE 7.000% PER ANNUM.
    THE CLASS IX-1 CERTIFICATES WILL ACCRUE INTEREST ON THE CLASS IX-1 NOTIONAL
    AMOUNT. THE "CLASS IX-1 NOTIONAL AMOUNT" WITH RESPECT TO ANY DISTRIBUTION
    DATE WILL EQUAL THE PRODUCT OF (X) THE AGGREGATE SCHEDULED PRINCIPAL
    BALANCE, AS OF THE SECOND PRECEDING DUE DATE AFTER GIVING EFFECT TO PAYMENTS
    SCHEDULED TO BE RECEIVED AS OF SUCH DUE DATE, WHETHER OR NOT RECEIVED, OR
    WITH RESPECT TO THE INITIAL DISTRIBUTION DATE, AS OF THE CUT-OFF DATE, OF
    THE GROUP I LOANS (AS DEFINED HEREIN) HAVING PASS-THROUGH RATES IN EXCESS OF
    7.000% PER ANNUM AND HAVING REMAINING TERMS TO MATURITY (REFLECTING
    CURTAILMENTS RECEIVED ON OR PRIOR TO THE CUT-OFF DATE) OF LESS THAN OR EQUAL
    TO 165 MONTHS AS OF THE CUT-OFF DATE (THE "CLASS IX-1 15-YEAR PREMIUM RATE
    MORTGAGE LOANS")(SUCH AGGREGATE BALANCE, THE "CLASS IX-1 PREMIUM LOAN
    BALANCE") AND (Y) A FRACTION, THE NUMERATOR OF WHICH IS THE WEIGHTED AVERAGE
    OF THE STRIPPED INTEREST RATES (AS DEFINED HEREIN) FOR THE CLASS IX-1
    15-YEAR PREMIUM RATE MORTGAGE LOANS AS OF SUCH DUE DATE AND THE DENOMINATOR
    OF WHICH IS 7.000% (THE "CLASS IX-1 PREMIUM FRACTION"). THE CLASS IX-1
    NOTIONAL AMOUNT AS OF THE CUT-OFF DATE WILL BE APPROXIMATELY $3,563,719. THE
    CLASS IX-1 CERTIFICATES WILL NOT BE ENTITLED TO RECEIVE DISTRIBUTIONS OF
    PRINCIPAL.
 
(7) THE REMITTANCE RATE ON THE CLASS IX-2 CERTIFICATES WILL BE 7.000% PER ANNUM.
    THE CLASS IX-2 CERTIFICATES WILL ACCRUE INTEREST ON THE CLASS IX-2 NOTIONAL
    AMOUNT. THE "CLASS IX-2 NOTIONAL AMOUNT" WITH RESPECT TO ANY DISTRIBUTION
    DATE WILL EQUAL THE PRODUCT OF (X) THE AGGREGATE SCHEDULED PRINCIPAL
    BALANCE, AS OF THE SECOND PRECEDING DUE DATE AFTER GIVING EFFECT TO PAYMENTS
    SCHEDULED TO BE RECEIVED AS OF SUCH DUE DATE, WHETHER OR NOT RECEIVED, OR
    WITH RESPECT TO THE INITIAL DISTRIBUTION DATE, AS OF THE CUT-OFF DATE, OF
    THE GROUP I LOANS HAVING PASS-THROUGH RATES IN EXCESS OF 7.000% PER ANNUM
    AND HAVING REMAINING TERMS TO MATURITY (REFLECTING CURTAILMENTS RECEIVED ON
    OR PRIOR TO THE CUT-OFF DATE) OF GREATER THAN 165 MONTHS AS OF THE CUT-OFF
    DATE (THE "CLASS IX-2 15-YEAR PREMIUM RATE MORTGAGE LOANS") (SUCH AGGREGATE
    BALANCE, THE "CLASS IX-2 PREMIUM LOAN BALANCE") AND (Y) A FRACTION, THE
    NUMERATOR OF WHICH IS THE WEIGHTED AVERAGE OF THE STRIPPED INTEREST RATES
    (AS DEFINED HEREIN) FOR THE CLASS IX-2 15-YEAR PREMIUM RATE MORTGAGE LOANS
    AS OF SUCH DUE DATE AND THE DENOMINATOR OF WHICH IS 7.000% (THE "CLASS IX-2
    PREMIUM FRACTION"). THE CLASS IX-2 NOTIONAL AMOUNT AS OF THE CUT-OFF DATE
    WILL BE APPROXIMATELY $6,117,050. THE CLASS IX-2 CERTIFICATES WILL NOT BE
    ENTITLED TO RECEIVE DISTRIBUTIONS OF PRINCIPAL.
 
(8) THE REMITTANCE RATE ON THE CLASS IIX CERTIFICATES WILL BE 7.500% PER ANNUM.
    THE CLASS IIX CERTIFICATES WILL ACCRUE INTEREST ON THE CLASS IIX FRACTION OF
    THE GROUP II NOTIONAL AMOUNT (THE "CLASS IIX NOTIONAL AMOUNT"). THE "CLASS
    IIX FRACTION" WITH RESPECT TO ANY DISTRIBUTION DATE WILL EQUAL
    30.2074506121%. THE "GROUP II NOTIONAL AMOUNT" WITH RESPECT TO ANY
    DISTRIBUTION DATE WILL EQUAL THE PRODUCT OF (X) THE AGGREGATE SCHEDULED
    PRINCIPAL BALANCE, AS OF THE SECOND PRECEDING DUE DATE AFTER GIVING EFFECT
    TO PAYMENTS SCHEDULED TO BE RECEIVED
 
                                      S-2
<PAGE>
(CONTINUED FROM PREVIOUS PAGE)
    AS OF SUCH DUE DATE, WHETHER OR NOT RECEIVED, OR WITH RESPECT TO THE INITIAL
    DISTRIBUTION DATE, AS OF THE CUT-OFF DATE, OF THE GROUP II LOANS (AS DEFINED
    HEREIN) HAVING PASS-THROUGH RATES IN EXCESS OF 7.500% PER ANNUM (THE
    "30-YEAR PREMIUM RATE MORTGAGE LOANS")(SUCH BALANCE, THE "GROUP II PREMIUM
    LOAN BALANCE") AND (Y) A FRACTION, THE NUMERATOR OF WHICH IS THE WEIGHTED
    AVERAGE OF THE STRIPPED INTEREST RATES (AS DEFINED HEREIN) FOR THE 30-YEAR
    PREMIUM RATE MORTGAGE LOANS AS OF SUCH DUE DATE AND THE DENOMINATOR OF WHICH
    IS 7.500% (THE "GROUP II PREMIUM FRACTION"). THE CLASS IIX NOTIONAL AMOUNT
    AS OF THE CUT-OFF DATE WILL BE APPROXIMATELY $5,525,230. THE CLASS IIX
    CERTIFICATES WILL NOT BE ENTITLED TO RECEIVE DISTRIBUTIONS OF PRINCIPAL.
 
(9) THE CLASS IP CERTIFICATES WILL NOT BE ENTITLED TO RECEIVE DISTRIBUTIONS OF
    INTEREST.
 
    The Certificates will evidence all the beneficial ownership interest in a
trust (the "Trust") established by the Company, the assets of which will consist
of a pool of conventional fixed-rate one- to four-family residential and
cooperative apartment mortgage loans with original terms to maturity of not more
than 30 years (the "Mortgage Loans") deposited and master serviced by the
Company, and certain other assets, as described herein. The Mortgage Pool (as
described herein) consists of two groups of Mortgage Loans ("Loan Group I" and
"Loan Group II", and each, a "Loan Group"). The Mortgage Loans in Loan Group I
are sometimes referred to as the "Group I Loans" and the Mortgage Loans in Loan
Group II are sometimes referred to as the "Group II Loans". The Group I
Certificates will correspond to the Group I Loans, which consist of fixed-rate
Mortgage Loans with terms to maturity of not more than 15 years. The Group II
Certificates will correspond to the Group II Loans, which consist of fixed-rate
Mortgage Loans with terms to maturity of not more than 30 years. Distributions
of interest and principal on the Group I Certificates and the Group II
Certificates will be solely based on interest and principal received or advanced
with respect to the Group I Loans and Group II Loans, respectively, except under
the limited circumstances described herein in "Description of the Certificates
- -- Cross-Collateralization".
 
    The Company intends to cause an election to be made to treat the Trust as a
"real estate mortgage investment conduit" (a "REMIC") for federal income tax
purposes. All of the certificates issued by the Trust, other than the Class R
Certificates, will represent ownership of REMIC "regular interests". The Class R
Certificates will represent ownership of the REMIC "residual interest" in the
Trust. See "Certain Federal Income Tax Consequences" herein and in the
Prospectus.
 
    The Offered Certificates evidence interests only in the Trust and are
payable solely from amounts received with respect thereto.
 
    The Company has the right to effect early retirement of the Certificates
under certain circumstances. See "Description of the Certificates -- Optional
Termination of the Trust" herein.
 
    The yield to maturity on any Class of Certificates generally will depend on
the rate and timing of principal payments (including prepayments, defaults and
liquidations) on the Mortgage Loans in the related Loan Group.
 
    The Companion Component of the Class IA-1 Certificates will be especially
sensitive to the rate of prepayment on the Group I Loans because such Companion
Component will receive distributions of principal on any Distribution Date only
to the extent of a percentage of the Group IA Principal Distribution Amount (as
defined herein) remaining, if any, after the Class IA-4, Class IA-5 and Class
IA-6 Certificates and the PAC Components of the Class IA-1 and Class IA-2
Certificates (the "Group I PACs") receive principal on such Distribution Date to
the extent of their respective Planned Principal Balances (as described herein).
The Class IA-7 Certificates also will be especially sensitive to the rate of
prepayment on the Group I Loans because the Class IA-7 Certificates will receive
distributions of principal on any Distribution Date only to the extent of a
percentage of the Group IA Principal Distribution Amount remaining, if any,
after distributions to the Group I PACs and the TAC Component of the Class IA-2
Certificates to the extent of its Targeted Principal Balance (as defined
herein). Furthermore, if the Group IA Principal Distribution Amount on any
Distribution Date is not sufficient to reduce the
 
                                      S-3
<PAGE>
(CONTINUED FROM PREVIOUS PAGE)
Class Principal or Component Balances of the Group I PACs to their Planned
Principal Balances, the Companion Component of the Class IA-1 Certificates, the
Class IA-7 Certificates and the TAC Component of the Class IA-2 Certificates
will receive no principal distributions on such Distribution Date, and if the
Group IA Principal Distribution Amount remaining to be distributed to the TAC
Component of the Class IA-2 Certificates is not sufficient to pay such Component
to its Targeted Principal Balance, the Class IA-7 Certificates will receive no
principal distribution on such Distribution Date.
 
    The Class IIA-5 Certificates will be especially sensitive to the rate of
prepayment on the Group II Loans because the Class IIA-5 Certificates will
receive distributions of principal on any Distribution Date only to the extent
of the portion of the Group IIA Principal Distribution Amount (as defined
herein) remaining, if any, after distributions to the Class IIA-2, Class IIA-6
and Class IIA-7 Certificates and the PAC Component of the Class IIA-1
Certificates (the "Group II PACs"), to the extent of their respective Planned
Principal Balances, and the Class IIA-3 Certificates and the TAC Component of
the Class IIA-1 Certificates (the "Group II TACs"), to the extent of their
respective Targeted Principal Balances. Furthermore, if the Group IIA Principal
Distribution Amount on any Distribution Date is not sufficient to reduce the
Class Principal or Component Balances of the Group II PACs to their Planned
Principal Balances and to reduce the Class Principal or Component Balances of
the Group II TACs to their Targeted Principal Balances, the Class IIA-5
Certificates will receive no principal distribution on such Distribution Date.
 
    The yields to maturity on the Class X and Class IP Certificates will be
extremely sensitive to the level of Principal Prepayments on the Mortgage Loans
in the related Loan Group. The interest payable to the Class IX-1 Certificates
is based on the weighted average of the Stripped Interest Rates of the Class
IX-1 15-Year Premium Rate Mortgage Loans. The interest payable to the Class IX-2
Certificates is based on the weighted average of the Stripped Interest Rates of
the Class IX-2 15-Year Premium Rate Mortgage Loans. The interest payable to the
Class IIX Certificates is based on the weighted average of the Stripped Interest
Rates of the 30-Year Premium Rate Mortgage Loans. Therefore the yield to
maturity on any Class of the Class X Certificates will generally decrease as a
result of faster than expected Principal Prepayments on the related Premium Rate
Mortgage Loans. Prospective investors should fully consider the risks associated
with an investment in any Class of the Class X Certificates, including the
possibility that if the rate of Principal Prepayments on the related Premium
Rate Mortgage Loans is rapid, such investors may not fully recoup their initial
investments. Because the principal payable with respect to the Class IP
Certificates (which are entitled to receive distributions of principal only) is
derived from Group I Loans with Pass-Through Rates that are lower than 7.000%,
the yield to maturity on the Class IP Certificates will be adversely affected by
slower than expected prepayments of Group I Loans with Pass-Through Rates less
than 7.000%. Because the interest payable on the Class IX Certificates and the
principal distributable to the Class IP Certificates are derived from different
groups of Mortgage Loans within Loan Group I, it is possible that faster than
expected Principal Prepayments with respect to the Class IX Certificates may
occur at the same time as slower than expected Principal Prepayments with
respect to the Class IP Certificates. See "Yield and Prepayment Considerations"
herein.
 
    The rights of the holders of the Senior Subordinate Certificates of either
Certificate Group to receive distributions of interest and principal are
subordinated to the rights of the holders of the Senior Certificates of such
Certificate Group to receive distributions of interest and principal. In
addition, the rights of the holders of the Class IB-2 and Class IIB-2
Certificates to receive distributions of interest and principal are subordinated
to the rights of the holders of the Class IB-1 and Class IIB-1 Certificates,
respectively, to receive distributions of interest and principal, and such
rights of the holders of the Class IB-3 and Class IIB-3 Certificates are
similarly subordinated to the rights of the holders of the Class IB-1 and Class
IB-2 Certificates and the Class IIB-1 and Class IIB-2 Certificates,
respectively. Furthermore, following the reduction of the aggregate Class
Principal Balance of the Junior Subordinate Certificates of a Certificate Group
to zero, the yield to maturity on each Class of the Senior Subordinate
Certificates of such Certificate Group will be extremely sensitive to certain
realized losses on the
 
                                      S-4
<PAGE>
(CONTINUED FROM PREVIOUS PAGE)
Mortgage Loans in the related Loan Group because a disproportionate amount of
such losses (rather than a pro rata portion thereof) generally will be allocable
to such Certificates, in the order Class IB-3, Class IB-2 and then Class IB-1,
in the case of Loan Group I and in the order Class IIB-3, Class IIB-2 and then
Class IIB-1, in the case of Loan Group II. Similarly, following the reduction of
the aggregate Class Principal Balance of the Class B Certificates of either
Certificate Group to zero, the yield to maturity on the Senior Certificates of
such Certificate Group will be extremely sensitive to all realized losses on the
Mortgage Loans in the related Loan Group. See "Description of the Certificates
- -- Subordination and Allocation of Losses" herein.
 
    Although the Lockout Certificates are Senior Certificates, the Class IA-3
and Class IIA-4 Certificates will generally not be entitled to receive any
distributions of Principal Prepayments until May 2002. Therefore, the Class IA-3
and Class IIA-4 Certificates will not be entitled to receive the
disproportionate allocation of Principal Prepayments in the related Loan Group
that the other Senior Certificates in the same Certificate Group are entitled to
receive. See "Description of the Certificates -- Distributions of Principal" and
"Yield and Prepayment Considerations" herein.
 
    The Offered Certificates, other than the Class X and Class R Certificates,
are offered in minimum denominations equivalent to not less than $25,000 initial
Certificate Principal Balance each and multiples of $1 in excess thereof, except
that one Class IP Certificate may be issued in a different amount. The Class X
Certificates are offered in minimum denominations equivalent to not less than
$100,000 initial Class Notional Amount each and multiples of $1 in excess
thereof, except that one Class IX-1, one Class IX-2 and one Class IIX
Certificate may be issued in a different amount. The Class R Certificates will
be offered in registered, certificated form in a single denomination of 99.99%
Percentage Interest. The remaining 0.01% Percentage Interest of the Class R
Certificates will be retained by the Company as set forth herein under "Certain
Federal Income Tax Consequences". There is at present no market for any Class of
Certificates and there can be no assurance that a secondary market for any Class
of Certificates will develop or, if it does develop, that it will provide
Certificateholders of such Class with liquidity of investment or will continue
for the life of such Class of Certificates.
 
    The Offered Certificates offered by this Supplement constitute a separate
Series of Certificates being offered by the Company from time to time pursuant
to the Prospectus dated November 21, 1996 of which this Supplement is a part and
which accompanies this Supplement. The Prospectus contains important information
regarding this offering which is not contained herein, and prospective investors
are urged to read the Prospectus and this Supplement in full.
 
    UNTIL THE EXPIRATION OF 90 DAYS AFTER THE DATE OF THIS SUPPLEMENT, ALL
DEALERS EFFECTING TRANSACTIONS IN THE OFFERED CERTIFICATES, WHETHER OR NOT
PARTICIPATING IN THIS DISTRIBUTION, MAY BE REQUIRED TO DELIVER A SUPPLEMENT AND
THE PROSPECTUS TO WHICH IT RELATES. THIS IS IN ADDITION TO THE OBLIGATION OF
DEALERS TO DELIVER A SUPPLEMENT AND PROSPECTUS WHEN ACTING AS UNDERWRITERS AND
WITH RESPECT TO THEIR UNSOLD ALLOTMENTS OR SUBSCRIPTIONS.
 
    NO PERSON HAS BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY
REPRESENTATIONS OTHER THAN THOSE CONTAINED IN THIS SUPPLEMENT AND THE PROSPECTUS
TO WHICH IT RELATES, AND, IF GIVEN OR MADE, SUCH INFORMATION OR REPRESENTATIONS
MUST NOT BE RELIED UPON. THIS SUPPLEMENT DOES NOT CONSTITUTE AN OFFER TO SELL OR
A SOLICITATION OF AN OFFER TO BUY ANY SECURITIES OTHER THAN THE OFFERED
CERTIFICATES OFFERED HEREBY NOR AN OFFER OF THE OFFERED CERTIFICATES TO ANY
PERSON IN ANY STATE OR OTHER JURISDICTION IN WHICH SUCH OFFER WOULD BE UNLAWFUL.
THE DELIVERY OF THIS SUPPLEMENT AT ANY TIME DOES NOT IMPLY THAT INFORMATION
HEREIN IS CORRECT AS OF ANY TIME SUBSEQUENT TO ITS DATE; HOWEVER, IF ANY
MATERIAL CHANGE OCCURS WHILE THIS SUPPLEMENT IS REQUIRED BY LAW TO BE DELIVERED,
THIS SUPPLEMENT WILL BE AMENDED OR SUPPLEMENTED ACCORDINGLY.
 
                                      S-5
<PAGE>
                               TABLE OF CONTENTS
 
<TABLE>
<CAPTION>
                                                                                                              PAGE
                                                                                                            ---------
<S>                                                                                                         <C>
SUMMARY INFORMATION.......................................................................................        S-7
RISK FACTORS..............................................................................................       S-45
  Effect of Principal Prepayments.........................................................................       S-45
  Cross-Collateralization.................................................................................       S-48
  Book-Entry System.......................................................................................       S-48
THE TRUST.................................................................................................       S-48
DESCRIPTION OF THE MORTGAGE POOL..........................................................................       S-49
  Loan Group I............................................................................................       S-49
  Loan Group II...........................................................................................       S-50
  Additional Information..................................................................................       S-51
DESCRIPTION OF THE CERTIFICATES...........................................................................       S-51
  General.................................................................................................       S-51
  Book-Entry Registration.................................................................................       S-54
  Definitive Certificates.................................................................................       S-55
  Priority of Distributions...............................................................................       S-55
  Distributions of Interest...............................................................................       S-60
  Distributions of Principal..............................................................................       S-62
  Principal Prepayment....................................................................................       S-69
  Cross-Collateralization.................................................................................       S-70
  Subordination and Allocation of Losses..................................................................       S-71
  The Class R Certificates................................................................................       S-74
  Advances................................................................................................       S-74
  Available Distribution Amount...........................................................................       S-74
  Last Scheduled Distribution Date........................................................................       S-76
  Optional Termination of the Trust.......................................................................       S-76
  Servicing Compensation and Payment of Expenses..........................................................       S-76
YIELD AND PREPAYMENT CONSIDERATIONS.......................................................................       S-77
  General.................................................................................................       S-77
  Principal Prepayments and Compensating Interest.........................................................       S-77
  Lockout Certificates....................................................................................       S-78
  Rate of Payments........................................................................................       S-78
  Special Sensitivities...................................................................................       S-78
  Basic Prepayment Assumption.............................................................................       S-79
  Yield Considerations with Respect to the Class X and Class IP Certificates..............................       S-80
  Yield Considerations with Respect to the Senior Subordinate Certificates................................       S-83
  Additional Yield Considerations Applicable Solely to the Class R Certificates...........................       S-88
  Additional Information..................................................................................       S-88
CREDIT ENHANCEMENTS.......................................................................................       S-88
  Subordination...........................................................................................       S-88
  Shifting of Interests...................................................................................       S-89
CERTAIN FEDERAL INCOME TAX CONSEQUENCES...................................................................       S-89
  Special Tax Considerations Applicable to the Residual Certificates......................................       S-90
CERTAIN LEGAL INVESTMENT ASPECTS..........................................................................       S-92
ERISA CONSIDERATIONS......................................................................................       S-93
  Underwriter's PTE.......................................................................................       S-93
  Prohibited Transaction Class Exemptions.................................................................       S-94
  Restrictions on Senior Subordinate and Residual Certificates............................................       S-94
METHOD OF DISTRIBUTION....................................................................................       S-94
LEGAL MATTERS.............................................................................................       S-95
CERTIFICATE RATINGS.......................................................................................       S-95
Appendix A................................................................................................       S-96
Appendix B................................................................................................      S-101
Appendix C................................................................................................      S-105
</TABLE>
 
                                      S-6
<PAGE>
                              SUMMARY INFORMATION
 
    THE FOLLOWING SUMMARY IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO THE
DETAILED INFORMATION APPEARING ELSEWHERE HEREIN AND IN THE PROSPECTUS.
CAPITALIZED TERMS USED HEREIN AND NOT OTHERWISE DEFINED HEREIN HAVE THE MEANINGS
ASSIGNED IN THE PROSPECTUS.
 
<TABLE>
<S>                                 <C>
Certificates......................  Mortgage Pass-Through Certificates, Series 1997-3 (the
                                    "Certificates"), consisting of the following thirty-one
                                    classes: (i) Class IA-1, Class IA-2, Class IA-3, Class
                                    IA-4, Class IA-5, Class IA-6 and Class IA-7 (the "Group
                                    IA Certificates"), (ii) Class IIA-1, Class IIA-2, Class
                                    IIA-3, Class IIA-4, Class IIA-5, Class IIA-6 and Class
                                    IIA-7 (the "Group IIA Certificates" and, together with
                                    the Group IA Certificates, the "Class A Certificates"),
                                    (iii) Class IP, (iv) Class IX-1 and Class IX-2 (the
                                    "Class IX Certificates") and Class IIX (together with
                                    the Class IX Certificates, the "Class X Certificates"),
                                    (v) Class IB-1, Class IB-2 and Class IB-3 (the "Group I
                                    Senior Subordinate Certificates"), (vi) Class IB-4,
                                    Class IB-5 and Class IB-6 (the "Group I Junior
                                    Subordinate Certificates" and, together with the Group I
                                    Senior Subordinate Certificates, the "Group IB
                                    Certificates"), (vii) Class IIB-1, Class IIB-2 and Class
                                    IIB-3 (the "Group II Senior Subordinate Certificates"),
                                    (viii) Class IIB-4, Class IIB-5 and Class IIB-6 (the
                                    "Group II Junior Subordinate Certificates" and, together
                                    with the Group II Senior Subordinate Certificates, the
                                    "Group IIB Certificates") and (ix) Class R (the
                                    "Residual Certificates" and, together with the Class A,
                                    Class X and Class IP Certificates, the "Senior
                                    Certificates"). The Group IA, Class IP, Class IX and
                                    Group IB Certificates are sometimes referred to as the
                                    "Group I Certificates" and the Group IIA, Class IIX and
                                    Group IIB Certificates are sometimes referred to as the
                                    "Group II Certificates". The Group I Certificates and
                                    the Group II Certificates are each a "Certificate
                                    Group". The Class IA-3 and Class IIA-4 Certificates are
                                    sometimes referred to as the "Lockout Certificates". The
                                    Group I Senior Subordinate Certificates and Group II
                                    Senior Subordinate Certificates are collectively
                                    referred to as the "Senior Subordinate Certificates".
                                    The Group I Junior Subordinate Certificates and Group II
                                    Junior Subordinate Certificates are collectively
                                    referred to as the "Junior Subordinate Certificates".
                                    The Group IB and Group IIB Certificates are collectively
                                    referred to as the "Subordinate Certificates" or "Class
                                    B Certificates". Only the Senior Certificates (other
                                    than the Class IIA-1 Certificates) and the Senior
                                    Subordinate Certificates (collectively, the "Offered
                                    Certificates") are offered hereby. The Class IIA-1
                                    Certificates and the Junior Subordinate Certificates are
                                    not offered hereby.
 
                                    The approximate initial Class Principal Balances and
                                    Remittance Rates of the Offered Certificates will be as
                                    described on the cover hereof.
 
                                    COMPONENTS.  Certain Classes of Certificates will be
                                    comprised of multiple components (each, a "Component"),
                                    each of which
</TABLE>
 
                                      S-7
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    will have a specified principal balance (a "Component
                                    Balance") or notional amount (a "Component Notional
                                    Amount") which functions in a manner comparable to that
                                    of a Class Principal Balance or Class Notional Amount,
                                    on which interest will accrue at a designated Remittance
                                    Rate. Holders of a Class of Certificates comprised of
                                    Components will be entitled to receive distributions on
                                    any Distribution Date to the extent of the amount
                                    distributed with respect to the related Components on
                                    such Distribution Date. Holders of a Class of
                                    Certificates comprised of Components may not transfer
                                    such Components separately.
 
                                    For purposes of calculating distributions, the Class
                                    IA-1 Certificates will be comprised of two Components
                                    having the designations, initial Component Balances and
                                    Remittance Rates set forth below:
</TABLE>
 
<TABLE>
<CAPTION>
                            INITIAL
DESIGNATION            COMPONENT BALANCE    REMITTANCE RATE
- ---------------------  ------------------  ------------------
<S>                    <C>                 <C>
PAC Component........     $ 11,330,672           7.000%
Companion Component..     $ 25,219,689           7.000%
</TABLE>
 
<TABLE>
<S>                                 <C>
                                    For purposes of calculating distributions, the Class
                                    IA-2 Certificates will be comprised of two Components
                                    having the designations, initial Component Balances and
                                    Remittance Rates set forth below:
</TABLE>
 
<TABLE>
<CAPTION>
                            INITIAL
DESIGNATION            COMPONENT BALANCE    REMITTANCE RATE
- ---------------------  ------------------  ------------------
<S>                    <C>                 <C>
PAC Component........     $  7,984,500           7.000%
TAC Component........     $ 11,800,000           7.000%
</TABLE>
 
<TABLE>
<CAPTION>
                                    For purposes of calculating distributions, the Class
                                    IIA-1 Certificates, which are not offered hereby, will
                                    be comprised of four Components having the designations,
                                    initial Component Balances and Remittance Rates set
                                    forth below:
 
                                                            INITIAL
DESIGNATION                                            COMPONENT BALANCE
- ----------------------------------                   ---------------------
                                           REMITTANCE
                                                              RATE
                                           --
<S>                                 <C>
PAC Component........     $  2,111,439           7.500%
TAC Component........     $ 56,279,967           7.500% (1)
IO Component.........               --           7.500% (2)
PO Component.........     $  1,270,136            (3)
</TABLE>
 
<TABLE>
<S>                                 <C>
                                    ------------------------
                                    (1) On each Distribution Date on or before the TAC
                                        Component Accretion Termination Date (as defined
                                        herein), an amount equal to the TAC Component
                                        Accrual Amount (as defined herein) will be added to
                                        the Component Balance of the TAC Component of the
                                        Class IIA-1 Certificates, and such amount will be
                                        distributed as principal on the Class IIA-3
                                        Certificates as described herein.
 
                                    (2) The Remittance Rate on the IO Component of the Class
                                        IIA-1 Certificates (the "IO Component") will be
                                        7.500% per annum. The IO Component will accrue
                                        interest on the IO Fraction of the Group II Notional
                                        Amount (the "IO Component Notional Amount"). The "IO
                                        Fraction" with respect to any Distribution Date will
                                        equal 69.7925493879%. The IO Component Notional
                                        Amount as of the Cut-Off Date will be approximately
                                        $12,765,721. The IO Component will not be entitled
                                        to receive distributions of principal.
 
                                    (3) The PO Component of the Class IIA-1 Certificates
                                        (the "PO Component") will not be entitled to
                                        distributions of interest.
</TABLE>
 
                                      S-8
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    The Certificates will evidence all the beneficial
                                    ownership interest in a trust (the "Trust") established
                                    by the Company, the assets of which will include the
                                    Mortgage Loans. The Company will cause an election to be
                                    made to treat the Trust as a real estate mortgage
                                    investment conduit (a "REMIC"). See "Description of the
                                    Certificates" herein.
 
The Mortgage Pool.................  The Mortgage Pool consists of two groups of Mortgage
                                    Loans ("Loan Group I" and "Loan Group II", and each, a
                                    "Loan Group").
 
                                    GROUP I LOANS. The Group I Loans consist of
                                    approximately 547 Mortgage Loans with an aggregate
                                    principal balance as of the Cut-Off Date of
                                    approximately $151,981,114. The principal balance at
                                    origination of each Group I Loan ranged from a minimum
                                    of approximately $23,150 to a maximum of approximately
                                    $1,000,000, with an average principal balance at
                                    origination of approximately $288,637. The Group I Loans
                                    have terms to maturity from the date of origination of
                                    not more than 15 years, with an average remaining term
                                    to maturity (adjusted for Curtailments) of approximately
                                    168.4 months as of the Cut-Off Date.
 
                                    GROUP II LOANS. The Group II Loans consist of
                                    approximately 1,296 Mortgage Loans with an aggregate
                                    principal balance as of the Cut-Off Date of
                                    approximately $359,049,223. The principal balance at
                                    origination of each Group II Loan ranged from a minimum
                                    of approximately $33,600 to a maximum of approximately
                                    $1,200,000, with an average principal balance at
                                    origination of approximately $277,622. The Group II
                                    Loans have terms to maturity from the date of
                                    origination of not more than 30 years, with a weighted
                                    average remaining term to maturity (adjusted for
                                    Curtailments) of approximately 356.6 months as of the
                                    Cut-Off Date.
 
                                    For a further description of the Mortgage Loans, see
                                    "Description of the Mortgage Pool" herein.
 
Initial Aggregate Certificate
  Principal Balance of the Offered
  Certificates....................  $446,638,440 (approximate, subject to an upward or
                                    downward variance of no more than 5%). With respect to
                                    the Group I Certificates, the Senior Certificates will
                                    comprise approximately 97.00%, the Senior Subordinate
                                    Certificates will comprise approximately 2.25%, and the
                                    Junior Subordinate Certificates will comprise
                                    approximately 0.75% of the initial aggregate Certificate
                                    Principal Balance of the Group I Certificates. With
                                    respect to the Group II Certificates, the Senior
                                    Certificates will comprise approximately 95.25%, the
                                    Senior Subordinate Certificates will comprise
                                    approximately 3.75%, and the Junior Subordinate
                                    Certificates will comprise approximately 1.00% of the
                                    initial aggregate Certificate Principal Balance of the
                                    Group II Certificates.
 
Mortgage Pool Initial Weighted
  Average Mortgage Interest
  Rate............................  8.021% (approximate).
</TABLE>
 
                                      S-9
<PAGE>
 
<TABLE>
<S>                                 <C>
Loan Group I Initial Weighted
  Average Mortgage Interest
  Rate............................  7.730% (approximate).
 
Loan Group II Initial Weighted
  Average Mortgage Interest
  Rate............................  8.145% (approximate).
 
The Trust.........................  The assets of the Trust will consist of a pool (the
                                    "Mortgage Pool") of Mortgage Loans, with an aggregate
                                    outstanding principal balance as of the Cut-Off Date of
                                    approximately $511,030,337. The Trust will also contain
                                    (i) certain insurance policies related to the Mortgage
                                    Loans, (ii) any property which secured a Mortgage Loan
                                    and which is acquired by foreclosure or by deed in lieu
                                    of foreclosure after the Cut-Off Date, (iii) amounts
                                    held in the Certificate Account, and (iv) certain other
                                    assets. See "The Trust" herein.
 
Depositor and Master Servicer.....  PNC Mortgage Securities Corp.
 
Trustee...........................  First Bank National Association.
 
Cut-Off Date......................  April 1, 1997.
 
Closing Date......................  On or about April 30, 1997.
 
Book-Entry Registration...........  Except in certain limited circumstances as described
                                    herein, the Class A Certificates which are Offered
                                    Certificates generally will be available only in
                                    book-entry form through the facilities of The Depository
                                    Trust Company ("DTC"). See "Description of the
                                    Certificates -- Book-Entry Registration" herein.
 
Cross-Collateralization...........  Special Hazard Losses incurred on Mortgage Loans in a
                                    Loan Group will be allocated to the Class of Subordinate
                                    Certificates then outstanding, regardless of Certificate
                                    Group, which has the lowest priority of payment (the
                                    "Lowest Class"), up to the Special Hazard Coverage;
                                    PROVIDED, HOWEVER, that in the event any Special Hazard
                                    Loss is incurred with respect to a Class IP Mortgage
                                    Loan or a PO Component Mortgage Loan (each, as defined
                                    herein), the applicable Class IP Fraction or PO
                                    Component Fraction (each as defined herein) of such loss
                                    will first be allocated to such Class IP Mortgage Loan
                                    or PO Component Mortgage Loan and the remainder of such
                                    loss will be allocated as described above. The Special
                                    Hazard Coverage as of the Closing Date will be
                                    $5,110,303. If at the time of the allocation of such
                                    Special Hazard Loss there is more than one Lowest Class
                                    of Subordinate Certificates outstanding, allocation of
                                    such Special Hazard Loss will be made on a pro rata
                                    basis to such Lowest Classes, based on their respective
                                    Class Principal Balances. In addition, all or a portion
                                    of the payments of principal otherwise distributable to
                                    the Lowest Class of the unrelated Certificate Group will
                                    be transferred to the Certificate Group relating to the
                                    Loan Group which incurred such Special Hazard Loss up to
                                    the amount of the loss allocated to such unrelated
                                    Lowest Class. The Certificate Group from which funds
                                    were transferred is a "Transferor Group" and the
                                    Certificate Group which receives such funds is a
                                    "Transferee Group". If the amount of principal payments
                                    otherwise distributable to the Lowest Class of a
                                    Transferor Group is less
</TABLE>
 
                                      S-10
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    than the amount of the allocation of the Special Hazard
                                    Loss to such Lowest Class, such shortfall will
                                    constitute a "Transfer Balance". In such event, the
                                    priority of distributions, the amount of interest and
                                    principal distributed and the calculation of the Group
                                    IA or Group IIA Percentage and the related Subordinate
                                    Percentage, with respect to the Transferor Group will be
                                    altered as described herein under "Description of
                                    Certificates -- Cross-Collateralization". The
                                    Distribution Date on which a Transfer Balance is created
                                    for a Certificate Group is referred to as a
                                    "Cross-Collateralization Date". It is expected that
                                    transfers in respect of Special Hazard Losses will occur
                                    and that Transfer Balances will be created.
 
Priority of Distributions.........  Commencing in May 1997, on the 25th day of each month,
                                    or if such 25th day is not a business day, on the
                                    immediately succeeding business day (each, a
                                    "Distribution Date"), distributions will be made in the
                                    order and priority as follows:
 
                                    (a) with respect to the Group I and Class R
                                        Certificates, prior to the Group I Credit Support
                                        Depletion Date (as defined herein), to the extent of
                                        the Available Distribution Amount for Loan Group I
                                        remaining following prior distributions, if any, on
                                        such Distribution Date:
 
                                        (i) first, to the Class IP Certificates, the Class
                                            IP Fraction (as defined herein) of all principal
                                            received on or in respect of each Class IP
                                            Mortgage Loan (as defined herein);
 
                                        (ii) second, (a) to the Group IA, Class IX and Class
                                            R Certificates, accrued and unpaid interest at
                                            their respective Remittance Rates on their
                                            respective Class Principal Balances (or the
                                            Class IX-1 and Class IX-2 Notional Amounts, in
                                            the case of the Class IX Certificates, and on
                                            their respective Component Balances, in the case
                                            of the PAC Component and Companion Component of
                                            the Class IA-1 Certificates and the PAC
                                            Component and TAC Component of the Class IA-2
                                            Certificates), reduced in the case of the Class
                                            IA-7 Certificates on or before the Class IA-7
                                            Accretion Termination Date (as defined herein)
                                            by the Class IA-7 Accrual Amount (as defined
                                            herein), and (b) on or before the Class IA-7
                                            Accretion Termination Date, to the TAC Component
                                            of the Class IA-2 Certificates, as principal, to
                                            the extent of the Component Balance of the TAC
                                            Component of the Class IA-2 Certificates, the
                                            Class IA-7 Accrual Amount;
 
                                        (iii) third, to the Group IA and the Class R
                                            Certificates, as principal, the Group IA
                                            Principal Distribution Amount (as defined
                                            herein) in the order described in "Description
                                            of the Certificates -- Distributions of
</TABLE>
 
                                      S-11
<PAGE>
 
<TABLE>
<S>                                 <C>
                                            Principal -- GROUP IA PRINCIPAL DISTRIBUTION
                                            AMOUNT" herein;
 
                                        (iv) fourth, to the Class IP Certificates, to the
                                            extent of amounts otherwise available to pay the
                                            Group I Subordinate Principal Distribution
                                            Amount (as defined herein) (without regard to
                                            clauses (I)(B) and (II) of such definition) on
                                            such Distribution Date, the sum of (a) principal
                                            in an amount equal to the Class IP Fraction of
                                            certain principal losses on the Class IP
                                            Mortgage Loans, as described in "Description of
                                            the Certificates -- Distributions of Principal
                                            -- CLASS IP DISTRIBUTION AMOUNT" herein and (b)
                                            the sum of amounts, if any, by which the amount
                                            described in clause (a) above on each prior
                                            Distribution Date exceeded the amount actually
                                            distributed in respect thereof on such prior
                                            Distribution Dates and not subsequently
                                            distributed; PROVIDED that any amounts
                                            distributed in respect of losses pursuant to
                                            this paragraph shall not cause a further
                                            reduction in the Class IP Principal Balance;
 
                                        (v) fifth, to the Class IB-1 Certificates, accrued
                                            and unpaid interest at the Class IB-1 Remittance
                                            Rate on the Class IB-1 Principal Balance;
 
                                        (vi) sixth, to the Class IB-1 Certificates, their
                                            pro rata share of the Group I Subordinate
                                            Principal Distribution Amount;
 
                                        (vii) seventh, to the Class IB-2 Certificates,
                                            accrued and unpaid interest at the Class IB-2
                                            Remittance Rate on the Class IB-2 Principal
                                            Balance;
 
                                        (viii) eighth, to the Class IB-2 Certificates, their
                                            pro rata share of the Group I Subordinate
                                            Principal Distribution Amount;
 
                                        (ix) ninth, to the Class IB-3 Certificates, accrued
                                            and unpaid interest at the Class IB-3 Remittance
                                            Rate on the Class IB-3 Principal Balance;
 
                                        (x) tenth, to the Class IB-3 Certificates, their pro
                                            rata share of the Group I Subordinate Principal
                                            Distribution Amount;
 
                                        (xi) eleventh, to the Group I Junior Subordinate
                                            Certificates, interest and principal in the same
                                            manner as for the Group I Senior Subordinate
                                            Certificates, first to the Class IB-4
                                            Certificates, then to the Class IB-5
                                            Certificates and then to the Class IB-6
                                            Certificates;
 
                                        (xii) twelfth, to each Class of Group I Subordinate
                                            Certificates in order of seniority, the
                                            remaining
</TABLE>
 
                                      S-12
<PAGE>
 
<TABLE>
<S>                                 <C>
                                            portion, if any, of the Available Distribution
                                            Amount for Loan Group I, up to the amount of
                                            unreimbursed realized losses previously
                                            allocated to such Class, if any, provided
                                            distribution of any amount pursuant to this
                                            paragraph shall not cause a further reduction in
                                            the Class Principal Balances of the Group I
                                            Subordinated Certificates; and
 
                                        (xiii) thirteenth, to the Class R Certificates, the
                                            remaining portion, if any, of the Available
                                            Distribution Amount for Loan Group I for such
                                            Distribution Date; and
 
                                    (b) with respect to the Group II and Class R
                                        Certificates, prior to the Group II Credit Support
                                        Depletion Date, to the extent of the Available
                                        Distribution Amount for Loan Group II remaining
                                        following prior distributions, if any, on such
                                        Distribution Date:
 
                                        (i) first, to the PO Component of the Class IIA-1
                                            Certificates, the PO Component Fraction (as
                                            defined herein) of all principal received on or
                                            in respect of each PO Component Mortgage Loan
                                            (as defined herein);
 
                                        (ii) second, (a) to the Group IIA and Class IIX
                                            Certificates, accrued and unpaid interest at
                                            their respective Remittance Rates on their
                                            respective Class Principal Balances (or the
                                            Class IIX Notional Amount in the case of the
                                            Class IIX Certificates and the respective
                                            Component Balances or Component Notional Amounts
                                            in the case of the PAC Component, TAC Component
                                            and IO Component of the Class IIA-1
                                            Certificates), reduced in the case of the TAC
                                            Component of the Class IIA-1 Certificates on or
                                            before the TAC Component Accretion Termination
                                            Date (as defined herein) by the TAC Component
                                            Accrual Amount (as defined herein), and further
                                            reduced in the case of the Class IIA-5
                                            Certificates on or before the Class IIA-5
                                            Accretion Termination Date (as defined herein)
                                            by the Class IIA-5 Accrual Amount (as defined
                                            herein), and (b) on or before the TAC Component
                                            Accretion Termination Date, to the Class IIA-3
                                            Certificates, as principal, to the extent of its
                                            Class Principal Balance, the sum of the TAC
                                            Component Accrual Amount and the Class IIA-5
                                            Accrual Amount and (c) after the TAC Component
                                            Accretion Termination Date until and including
                                            the Class IIA-5 Accretion Termination Date, to
                                            the TAC Component of the Class IIA-1
                                            Certificates, as principal, to the extent of the
                                            TAC Component Balance of the Class IIA-1
                                            Certificates, the Class IIA-5 Accrual Amount;
</TABLE>
 
                                      S-13
<PAGE>
 
<TABLE>
<S>                                 <C>
                                        (iii) third, to the Group IIA Certificates (other
                                            than the PO Component of the Class IIA-1
                                            Certificates), as principal, the Group IIA
                                            Principal Distribution Amount in the order
                                            described in "Description of the Certificates --
                                            Distributions of Principal -- GROUP IIA
                                            PRINCIPAL DISTRIBUTION AMOUNT" herein;
 
                                        (iv) fourth, to the PO Component of the Class IIA-1
                                            Certificates, to the extent of amounts otherwise
                                            available to pay the Group II Subordinate
                                            Principal Distribution Amount (as defined
                                            herein) (without regard to clauses (I)(B) and
                                            (II) of such definition) on such Distribution
                                            Date, the sum of (a) principal in an amount
                                            equal to the PO Component Fraction of certain
                                            principal losses on the PO Component Mortgage
                                            Loans, as described in "Description of the
                                            Certificates -- Distributions of Principal -- PO
                                            COMPONENT PRINCIPAL DISTRIBUTION AMOUNT" herein
                                            and (b) the sum of amounts, if any, by which the
                                            amount described in clause (a) above on each
                                            prior Distribution Date exceeded the amount
                                            actually distributed in respect thereof on such
                                            prior Distribution Dates and not subsequently
                                            distributed; PROVIDED that any amounts dis-
                                            tributed in respect of losses pursuant to this
                                            paragraph shall not cause a further reduction in
                                            the PO Component Balance;
 
                                        (v) fifth, to the Class IIB-1 Certificates, accrued
                                            and unpaid interest at the Class IIB-1
                                            Remittance Rate on the Class IIB-1 Principal
                                            Balance;
 
                                    (vi) sixth, to the Class IIB-1 Certificates, their pro
                                    rata share of the Group II Subordinate Principal
                                         Distribution Amount;
 
                                    (vii) seventh, to the Class IIB-2 Certificates, accrued
                                    and unpaid interest at the Class IIB-2 Remittance Rate
                                          on the Class IIB-2 Principal Balance;
 
                                    (viii) eighth, to the Class IIB-2 Certificates, their
                                    pro rata share of the Group II Subordinate Principal
                                           Distribution Amount;
 
                                    (ix) ninth, to the Class IIB-3 Certificates, accrued and
                                         unpaid interest at the Class IIB-3 Remittance Rate
                                         on the Class IIB-3 Principal Balance;
 
                                    (x) tenth, to the Class IIB-3 Certificates, their pro
                                    rata share of the Group II Subordinate Principal
                                        Distribution Amount;
 
                                    (xi) eleventh, to the Group II Junior Subordinate
                                    Certificates, interest and principal in the same manner
                                         as for the Group II Senior Subordinate
                                         Certificates, first to the Class IIB-4
                                         Certificates, then to the Class IIB-5 Certificates
                                         and then to the Class IIB-6 Certificates;
</TABLE>
 
                                      S-14
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    (xii) twelfth, to each Class of Group II Subordinate
                                    Certificates in order of seniority, the remaining
                                          portion, if any, of the Available Distribution
                                          Amount for Loan Group II, up to the amount of
                                          unreimbursed realized losses previously allocated
                                          to such Class, if any, provided distribution of
                                          any amount pursuant to this paragraph shall not
                                          cause a further reduction in the Class Principal
                                          Balances of the Group II Subordinated
                                          Certificates; and
 
                                    (xiii) thirteenth, to the Class R Certificates, the
                                    remaining portion, if any, of the Available Distribution
                                           Amount for Loan Group II for such Distribution
                                           Date.
 
                                    The Class IA-7 Accretion Termination Date is the earlier
                                    to occur of (i) the Distribution Date on which the
                                    Component Balance of the TAC Component of the Class IA-2
                                    Certificates has been reduced to zero and (ii) the Group
                                    I Credit Support Depletion Date. On each Distribution
                                    Date on or before the Class IA-7 Accretion Termination
                                    Date, an amount (the "Class IA-7 Accrual Amount") equal
                                    to the lesser of (i) the accrued interest that would
                                    otherwise be distributable in respect of the Class IA-7
                                    Certificates on such Distribution Date and (ii) the
                                    Component Balance of the TAC Component of the Class IA-2
                                    Certificates will be added to the Class IA-7 Principal
                                    Balance, and such amount will be distributed, as
                                    principal, to the TAC Component of the Class IA-2
                                    Certificates. The amount so added to the Class IA-7
                                    Principal Balance will thereafter accrue interest at the
                                    Class IA-7 Remittance Rate.
 
                                    The TAC Component Accretion Termination Date is the
                                    earlier to occur of (i) the Distribution Date on which
                                    the Class IIA-3 Principal Balance has been reduced to
                                    zero and (ii) the Group II Credit Support Depletion
                                    Date. On each Distribution Date on or before the TAC
                                    Component Accretion Termination Date, an amount (the
                                    "TAC Component Accrual Amount") equal to the lesser of
                                    (i) the accrued interest that would otherwise be
                                    distributable in respect of the TAC Component of the
                                    Class IIA-1 Certificates on such Distribution Date and
                                    (ii) the Class IIA-3 Principal Balance will be added to
                                    the Component Balance of the TAC Component of the Class
                                    IIA-1 Certificates, and such amount will be distributed,
                                    as principal, to the Class IIA-3 Certificates. The
                                    amount so added to the Component Balance of the TAC
                                    Component of the Class IIA-1 Certificates will thereaf-
                                    ter accrue interest at the Remittance Rate for the TAC
                                    Component of the Class IIA-1 Certificates.
 
                                    The Class IIA-5 Accretion Termination Date is the
                                    earlier to occur of (i) the Distribution Date on which
                                    the Component Balance of the TAC Component of the Class
                                    IIA-1 Certificates has been reduced to zero and (ii) the
                                    Group II Credit Support Depletion Date. On each
                                    Distribution Date on or before the Class IIA-5 Accretion
                                    Termination Date, an amount (the "Class IIA-5 Accrual
                                    Amount") equal to the lesser of (i) the
</TABLE>
 
                                      S-15
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    accrued interest that would otherwise be distributable
                                    in respect of the Class IIA-5 Certificates on such
                                    Distribution Date and (ii) the Component Balance of the
                                    TAC Component of the Class IIA-1 Certificates will be
                                    added to the Class IIA-5 Principal Balance, and such
                                    amount will be distributed, as principal, sequentially
                                    (a) to the Class IIA-3 Certificates, until the Class
                                    IIA-3 Principal Balance is reduced to zero and (b) to
                                    the TAC Component of the Class IIA-1 Certificates until
                                    the Component Balance thereof is reduced to zero. The
                                    amounts so added to the Class IIA-5 Principal Balance
                                    will thereafter accrue interest at the Class IIA-5
                                    Remittance Rate.
 
                                    With respect to the Class B Certificates of each
                                    Certificate Group, notwithstanding the foregoing, on any
                                    Distribution Date on which the Subordination Level (as
                                    defined herein) for any Class of Class B Certificates in
                                    a Certificate Group is less than such percentage as of
                                    the Cut-Off Date, the portion of the Subordinate
                                    Principal Distribution Amount of the related Cer-
                                    tificate Group otherwise allocable to the Class or
                                    Classes of the Class B Certificates in the related
                                    Certificate Group junior to such Class will be allocated
                                    to the most senior Class of Class B Certificates in the
                                    related Certificate Group for which the Subordination
                                    Level is less than such percentage as of the Cut-Off
                                    Date and to the Class or Classes of Class B Certificates
                                    in the related Certificate Group senior thereto, pro
                                    rata according to the Class Principal Balances of such
                                    Classes.
 
                                    The "Subordination Level" on any specified date with
                                    respect to any Class of Class B Certificates is the
                                    percentage obtained by dividing the sum of the Class
                                    Principal Balances of all Classes of Certificates in the
                                    related Certificate Group which are subordinate in right
                                    of payment to such Class by the sum of the Class
                                    Principal Balances of all of the Certificates in the
                                    related Certificate Group as of such date prior to
                                    giving effect to distributions or allocations of
                                    realized losses on the Mortgage Loans in the related
                                    Loan Group on such date.
 
                                    On each Distribution Date on or after the Group I Credit
                                    Support Depletion Date, distributions will be made with
                                    respect to the Group I and Class R Certificates,
                                    subject, in each case, to the extent of the Available
                                    Distribution Amount of Loan Group I remaining following
                                    prior distributions, if any, on such Distribution Date:
 
                                    (i) first, to the Class IP Certificates, the Class IP
                                    Fraction of all principal received on or in respect of
                                        each Class IP Mortgage Loan;
 
                                    (ii) second, to the Group IA, Class IX and Class R
                                    Certificates, accrued and unpaid interest at their
                                         respective Remittance Rates on their respective
                                         Class Principal Balances (or the Class IX-1 and
                                         Class IX-2 Notional Amounts, in the case of the
                                         Class IX Certificates, and on their respective
                                         Component Balances, in the case of
</TABLE>
 
                                      S-16
<PAGE>
 
<TABLE>
<S>                                 <C>
                                         the PAC Component and Companion Component of the
                                         Class IA-1 Certificates and the PAC Component and
                                         TAC Component of the Class IA-2 Certificates);
 
                                    (iii) third, to the Group IA Certificates and the Class
                                    R Certificates, the Group IA Principal Distribution
                                          Amount, pro rata according to their respective
                                          Class Principal Balances; and
 
                                    (iv) fourth, to the Class R Certificates, the remaining
                                    portion, if any, of the Available Distribution Amount
                                         for Loan Group I for such Distribution Date, as
                                         described in the Pooling Agreement.
 
                                    The "Group I Credit Support Depletion Date" is the first
                                    Distribution Date on which the aggregate of the Class
                                    Principal Balances of the Group IB Certificates has been
                                    or will be reduced to zero.
 
                                    On each Distribution Date on or after the Group II
                                    Credit Support Depletion Date, distributions will be
                                    made with respect to the Group II and Class R
                                    Certificates, subject, in each case, to the extent of
                                    the Available Distribution Amount of Loan Group II
                                    remaining following prior distributions, if any, on such
                                    Distribution Date:
 
                                    (i) first, to the PO Component of the Class IIA-1
                                    Certificates, the PO Component Fraction of all principal
                                        received on or in respect of each PO Component
                                        Mortgage Loan;
 
                                    (ii) second, to the Group II Certificates (other than
                                    the PO Component of the Class IIA-1 Certificates),
                                         accrued and unpaid interest at their respective
                                         Remittance Rates on their respective Class
                                         Principal Balances (or Class IIX Notional Amount in
                                         the case of the Class IIX Certificates and on their
                                         respective Component Balances and Component
                                         Notional Amounts, in the case of the PAC Component,
                                         TAC Component and IO Component of the Class IIA-1
                                         Certificates);
 
                                    (iii) third, to the Group IIA Certificates, the Group
                                    IIA Principal Distribution Amount, pro rata according to
                                          their respective Class Principal Balances (or the
                                          Component Balances, other than the PO Component
                                          Balance, in the case of the Class IIA-1
                                          Certificates); and
 
                                    (iv) fourth, to the Class R Certificates, the remaining
                                    portion, if any, of the Available Distribution Amount
                                         for Loan Group II for such Distribution Date, as
                                         described in the Pooling Agreement.
 
                                    The "Group II Credit Support Depletion Date" is the
                                    first Distribution Date on which the aggregate of the
                                    Class Principal Balances of the Group IIB Certificates
                                    has been or will be reduced to zero.
</TABLE>
 
                                      S-17
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    Except for the limited circumstances described herein
                                    under "Description of the Certificates --
                                    Cross-Collateralization", distributions of interest and
                                    principal to the Group I Certificates and the Group II
                                    Certificates will be based solely on payments received
                                    with respect to Group I Loans and Group II Loans,
                                    respectively.
 
Interest..........................  With respect to each Class of Certificates (except the
                                    Class IP Certificates and the PO Component of the Class
                                    IIA-1 Certificates, which are not entitled to interest),
                                    interest will be passed through monthly on each
                                    Distribution Date, commencing in May 1997, except that
                                    (1) interest accrued on the Class IA-7 Certificates on
                                    or before the Class IA-7 Accretion Termination Date will
                                    be added to the Class IA-7 Principal Balance, (2) inter-
                                    est accrued on the TAC Component of the Class IIA-1
                                    Certificates on or before the TAC Component Accretion
                                    Termination Date will be added to the TAC Component
                                    Balance of the Class IIA-1 Certificates and (3) interest
                                    accrued on the Class IIA-5 Certificates on or before the
                                    Class IIA-5 Accretion Termination Date will be added to
                                    the Class IIA-5 Principal Balance. With respect to each
                                    Distribution Date, an amount of interest will accrue on
                                    each Class of Certificates (other than the Class IP
                                    Certificates), or, with respect to the Class IA-1
                                    Certificates, the PAC Component and Companion Component,
                                    or, with respect to the Class IA-2 Certificates, the PAC
                                    Component and TAC Component, or, with respect to the
                                    Class IIA-1 Certificates, the PAC Component, TAC
                                    Component and IO Component, generally equal to 1/12th of
                                    the applicable Remittance Rate for such Class or
                                    Component multiplied by the related Class Principal
                                    Balance, Component Balance, Class Notional Amount or
                                    Component Notional Amount, as applicable. Interest will
                                    not accrue on the Class IP Certificates nor on the PO
                                    Component of the Class IIA-1 Certificates. Interest to
                                    be distributed on the Certificates on any Distribution
                                    Date will consist of accrued and unpaid interest as of
                                    previous Distribution Dates and interest accrued during
                                    the preceding calendar month. All distributions of
                                    interest for each Class of Certificates will generally
                                    be made only to the extent of the Available Distribution
                                    Amount for the related Loan Group as described herein
                                    under "Description of the Certificates -- Priority of
                                    Distributions"
 
                                    The Remittance Rates for the Class A, Class X, Class R
                                    and Senior Subordinate Certificates are fixed as set
                                    forth on the cover page hereof. The Remittance Rates for
                                    the PAC Component and the Companion Component of the
                                    Class IA-1 Certificates will each be 7.000%. The
                                    Remittance Rates for the PAC Component and the TAC
                                    Component of the Class IA-2 Certificates will each be
                                    7.000%. The Remittance Rates for the PAC Component and
                                    the TAC Component of the Class IIA-1 Certificates will
                                    each be 7.500%. The Class X Certificates and the IO
                                    Component will accrue interest on the applicable Class
                                    Notional Amount and Component Notional Amount,
                                    respectively. The
</TABLE>
 
                                      S-18
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    "Class IX-1 Notional Amount" with respect to any
                                    Distribution Date will equal the product of (x) the
                                    Class IX-1 Premium Loan Balance and (y) the Class IX-1
                                    Premium Fraction. The Class IX-1 Notional Amount as of
                                    the Cut-Off Date will be approximately $3,563,719. The
                                    "Class IX-2 Notional Amount" with respect to any
                                    Distribution Date will equal the product of (x) the
                                    Class IX-2 Premium Loan Balance and (y) the Class IX-2
                                    Premium Fraction. The Class IX-2 Notional Amount as of
                                    the Cut-Off Date will be approximately $6,117,050. The
                                    "Stripped Interest Rate" for each Group I Loan is the
                                    excess, if any, of the Pass-Through Rate for such
                                    Mortgage Loan over 7.000%.
 
                                    The "Class IIX Notional Amount" with respect to any
                                    Distribution Date will equal the Class IIX Fraction of
                                    the Group II Notional Amount. The Group II Notional
                                    Amount with respect to any Distribution Date will equal
                                    the product of (x) the Group II Premium Loan Balance and
                                    (y) the Group II Premium Fraction. The Class IIX
                                    Notional Amount as of the Cut-Off Date will be
                                    approximately $5,525,230. The "Stripped Interest Rate"
                                    for each Group II Loan is the excess, if any, of the
                                    Pass-Through Rate for such Mortgage Loan over 7.500%.
 
                                    The "IO Component Notional Amount" with respect to any
                                    Distribution Date will equal the IO Fraction of the
                                    Group II Notional Amount. The IO Component Notional
                                    Amount as of the Cut-Off Date will be approximately
                                    $12,765,721.
 
                                    The "Pass-Through Rate" for each Mortgage Loan is equal
                                    to the Mortgage Interest Rate thereon less the sum of
                                    the related Master Servicing Fee and Servicing Fee
                                    (each, as defined herein).
 
Compensating Interest.............  Subject to the limitations described in this Prospectus
                                    Supplement under "Yield and Prepayment Considerations",
                                    the Master Servicer is obligated to pass through on each
                                    Distribution Date an amount equal to the lesser of (a)
                                    any shortfall for the related month in interest
                                    collections resulting from the timing of Payoffs made
                                    from the 15th day of the calendar month preceding such
                                    Distribution Date to the last day of such month and (b)
                                    the monthly Master Servicing Fee, any reinvestment
                                    income realized by the Master Servicer relating to
                                    Payoffs made from the 15th day of the calendar month
                                    preceding such Distribution Date to the 14th day of the
                                    month of such Distribution Date and interest payments on
                                    Payoffs received during the period of the first day
                                    through the 14th day of the month of such Distribution
                                    Date. The amount so passed through will hereinafter be
                                    referred to as "Compensating Interest". Compensating
                                    Interest will be allocated to each Class of Certificates
                                    pro rata according to the amount of interest accrued
                                    thereon, and any remaining shortfall in interest
                                    collections resulting from the timing of Payoffs will be
                                    applied pro rata according to the amount of interest to
                                    which each Class of Certificates would otherwise be
                                    entitled in reduction thereof.
</TABLE>
 
                                      S-19
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    See "Description of the Certificates -- Distributions of
                                    Interest" herein.
 
Principal (including Principal
  Prepayments)....................  GENERAL.  On each Distribution Date, Certificateholders
                                    will be entitled to receive principal distributions from
                                    the Available Distribution Amount to the extent and
                                    priority described herein. See "Description of the
                                    Certificates -- Priority of Distributions" and " --
                                    Distributions of Principal" herein. Except for limited
                                    circumstances described under "Description of the
                                    Certificates -- Cross-Collateralization" herein, the
                                    Group I Certificates (other than the Class IX
                                    Certificates which will not receive principal) will
                                    receive principal collected from Group I Loans and the
                                    Group II Certificates (other than the Class IIX Certifi-
                                    cates and the IO Component of the Class IIA-1
                                    Certificates which will not receive principal) will
                                    receive principal collected from Group II Loans.
 
                                    Group I Certificate Principal Distributions
 
                                    CLASS IP PRINCIPAL DISTRIBUTION AMOUNT.  On each
                                    Distribution Date, the Class IP Certificates will
                                    receive a portion of the Available Distribution Amount
                                    for Loan Group I attributable to principal received on
                                    or in respect of any Group I Loan with a Pass-Through
                                    Rate of less than 7.000% (a "Class IP Mortgage Loan"),
                                    equal to the amount of such principal so attributable
                                    multiplied by a fraction, the numerator of which is
                                    7.000% minus the Pass-Through Rate on such Class IP
                                    Mortgage Loan and the denominator of which is 7.000%
                                    (the "Class IP Fraction"). In addition, on each
                                    Distribution Date for so long as any Class of Group IB
                                    Certificates remains outstanding, the Class IP
                                    Certificates will also be allocated principal, to the
                                    extent of amounts available to pay the Group I
                                    Subordinate Principal Distribution Amount (without
                                    regard to clauses (I)(B) and (II) of such definition) on
                                    such Distribution Date, in an amount generally equal to
                                    (i) the Class IP Fraction of any loss on a Class IP
                                    Mortgage Loan other than a Special Hazard Loss in excess
                                    of the Special Hazard Coverage, a Fraud Loss in excess
                                    of the Group I Fraud Coverage or a Bankruptcy Loss in
                                    excess of the Group I Bankruptcy Coverage (each, as
                                    defined herein) and (ii) the sum of amounts, if any, by
                                    which the foregoing amount on each prior Distribution
                                    Date exceeded the amount actually distributed in respect
                                    thereof on such prior Distribution Dates and not
                                    subsequently distributed; PROVIDED, that such payments
                                    in respect of losses shall not cause a further reduction
                                    of the outstanding Class IP Principal Balance. The
                                    aggregate of the amounts payable to the Class IP
                                    Certificates described in this paragraph are referred to
                                    herein as the "Class IP Principal Distribution Amount".
 
                                    GROUP IA PRINCIPAL DISTRIBUTION AMOUNT.  On each
                                    Distribution Date prior to the Group I Credit Support
                                    Depletion Date, an amount, up to the amount of the Group
                                    IA Principal Distribution Amount (as defined below) for
                                    such Distribution Date, will
</TABLE>
 
                                      S-20
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    be distributed as principal to the following Classes of
                                    Group IA Certificates and Class R Certificates in the
                                    following order of priority:
 
                                    (i) first, to the Class IA-3 Certificates, an amount, up
                                    to the amount of the Class IA-3 Principal Distribution
                                        Amount (as defined below) for such Distribution
                                        Date, until the Class IA-3 Principal Balance has
                                        been reduced to zero;
 
                                    (ii) second, the portion of the Group IA Principal
                                    Distribution Amount remaining after the distribution
                                         described above, concurrently:
 
                                    (A) 58.6620300352% to the PAC Component of the Class
                                        IA-1 Certificates, to the extent necessary to reduce
                                        the Component Balance of such PAC Component to its
                                        planned principal balance for such Distribution
                                        Date, as set forth in Appendix A herein (its
                                        "Planned Principal Balance"); and
 
                                    (B) 41.3379699648% to the PAC Component of the Class
                                        IA-2 Certificates, to the extent necessary to reduce
                                        the Component Balance of such PAC Component to its
                                        Planned Principal Balance for such Distribution
                                        Date;
 
                                    (iii) third, to the Class IA-4 Certificates, the portion
                                    of the Group IA Principal Distribution Amount remaining
                                          after the distributions described above, to the
                                          extent necessary to reduce the Class IA-4
                                          Principal Balance to its Planned Principal Balance
                                          for such Distribution Date;
 
                                    (iv) fourth, to the Class IA-5 Certificates, the portion
                                    of the Group IA Principal Distribution Amount remaining
                                         after the distributions described above, to the
                                         extent necessary to reduce the Class IA-5 Principal
                                         Balance to its Planned Principal Balance for such
                                         Distribution Date;
 
                                    (v) fifth, to the Class IA-6 Certificates, the portion
                                    of the Group IA Principal Distribution Amount remaining
                                        after the distributions described above, to the
                                        extent necessary to reduce the Class IA-6 Principal
                                        Balance to its Planned Principal Balance for such
                                        Distribution Date;
 
                                    (vi) sixth, the portion of the Group IA Principal
                                    Distribution Amount remaining after the distributions
                                         described above, concurrently:
 
                                    (A) 65.2751643521% to the Companion Component of the
                                        Class IA-1 Certificates until the Component Balance
                                        of such Companion Component has been reduced to
                                        zero; and
 
                                    (B) 34.7248356479% sequentially as follows:
</TABLE>
 
                                      S-21
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    (1) first, to the TAC Component of the Class IA-2
                                        Certificates to the extent necessary to reduce the
                                        Component Balance of such TAC Component to its
                                        targeted principal balance for such Distribution
                                        Date, as set forth in Appendix B herein (its
                                        "Targeted Principal Balance");
 
                                    (2) second, to the Class IA-7 Certificates until the
                                        Class IA-7 Principal Balance has been reduced to
                                        zero; and
 
                                    (3) third, to the TAC Component of the Class IA-2
                                        Certificates until the Component Balance of such TAC
                                        Component has been reduced to zero;
 
                                    (vii) seven, to the Class R Certificates, the portion of
                                    the Group IA Principal Distribution Amount remaining
                                          after the distributions described above, until the
                                          Class R Principal Balance has been reduced to
                                          zero;
 
                                    (viii) eighth, the portion of the Group IA Principal
                                           Distribution Amount remaining after the
                                           distributions described above, concurrently:
 
                                    (A) 58.6620300352% to the PAC Component of the Class
                                        IA-1 Certificates, until the Component Balance of
                                        such PAC Component has been reduced to zero; and
 
                                    (B) 41.3379699648% to the PAC Component of the Class
                                        IA-2 Certificates, until the Component Balance of
                                        such PAC Component has been reduced to zero;
 
                                    (ix) ninth, to the Class IA-4 Certificates, the portion
                                    of the Group IA Principal Distribution Amount remaining
                                         after the distributions described above, until the
                                         Class IA-4 Principal Balance has been reduced to
                                         zero;
 
                                    (x) tenth, to the Class IA-5 Certificates, the portion
                                    of the Group IA Principal Distribution Amount remaining
                                        after the distributions described above, until the
                                        Class IA-5 Principal Balance has been reduced to
                                        zero;
 
                                    (xi) eleventh, to the Class IA-6 Certificates, the
                                    portion of the Group IA Principal Distribution Amount
                                         remaining after the distributions described above,
                                         until the Class IA-6 Principal Balance has been
                                         reduced to zero; and
 
                                    (xii) twelfth, to the Class IA-3 Certificates, the
                                    portion of the Group IA Principal Distribution Amount
                                          remaining after the distributions described above,
                                          until the Class IA-3 Principal Balance has been
                                          reduced to zero.
</TABLE>
 
                                      S-22
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    The "Group IA Principal Distribution Amount" for any
                                    Distribution Date will equal the sum of (i) the Group IA
                                    Percentage (as defined below) of the Principal Payment
                                    Amount (as defined below) for Loan Group I (exclusive of
                                    the portion thereof attributable to the Class IP
                                    Principal Distribution Amount), (ii) the Group IA
                                    Prepayment Percentage (as defined below) of the
                                    Principal Prepayment Amount (as defined below) for Loan
                                    Group I (exclusive of the portion thereof attributable
                                    to the Class IP Principal Distribution Amount), and
                                    (iii) the Group IA Liquidation Amount (as defined
                                    below).
 
                                    The "Group IA Percentage" for any Distribution Date will
                                    equal the sum of the Class Principal Balances of the
                                    Group IA Certificates and the Class R Certificates
                                    divided by the aggregate Class Principal Balance of the
                                    Group I Certificates and Class R Certificates (less the
                                    Class IP Principal Balance), in each case immediately
                                    prior to the Distribution Date.
 
                                    The "Group IA Liquidation Amount" is the aggregate of,
                                    for each Group I Loan which became a Liquidated Mortgage
                                    Loan during the calendar month preceding the month of
                                    the Distribution Date, the lesser of (i) the Group IA
                                    Percentage of the principal balance of such Mortgage
                                    Loan (exclusive of the Class IP Fraction thereof, with
                                    respect to any Class IP Mortgage Loan) and (ii) the
                                    Group IA Prepayment Percentage of the Liquidation
                                    Principal with respect to such Mortgage Loan.
 
                                    "Liquidation Principal" is the principal portion of
                                    Liquidation Proceeds received with respect to each
                                    Mortgage Loan which became a Liquidated Mortgage Loan
                                    (as defined herein) (but not in excess of the principal
                                    balance thereof) during the calendar month preceding the
                                    month of the Distribution Date, exclusive of the portion
                                    thereof attributable to the applicable Class IP
                                    Principal Distribution Amount or PO Component Principal
                                    Distribution Amount. A "Liquidated Mortgage Loan" is a
                                    Mortgage Loan as to which the Master Servicer or a
                                    servicer has determined that all amounts which it
                                    expects to recover from or on account of such Mortgage
                                    Loan, whether from Insurance Proceeds, Liquidation
                                    Proceeds or otherwise have been recovered.
 
                                    The "Group I Subordinate Percentage" for any
                                    Distribution Date will equal the excess of 100% over the
                                    Group IA Percentage for such date. The Group IA
                                    Percentage and the Group I Subordinate Percentage as of
                                    the Cut-Off Date will be approximately 97.00% and 3.00%,
                                    respectively.
 
                                    The "Class IA-3 Principal Distribution Amount" for any
                                    Distribution Date will equal the sum of (i) the Class
                                    IA-3 Percentage (as defined below) of the Principal
                                    Payment Amount for Loan Group I (exclusive of the
                                    portion thereof attributable to the Class IP Principal
                                    Distribution Amount), (ii) the Class IA-3 Prepayment
                                    Percentage (as defined herein) of the Principal
                                    Prepayment Amount for Loan Group I (exclusive of
</TABLE>
 
                                      S-23
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    the portion thereof attributable to the Class IP
                                    Principal Distribution Amount) and (iii) the Class IA-3
                                    Liquidation Amount (as defined below).
 
                                    The "Class IA-3 Percentage" for any Distribution Date
                                    will equal the Class IA-3 Principal Balance divided by
                                    the aggregate Class Principal Balance of the Group I
                                    Certificates and Class R Certificates (less the Class IP
                                    Principal Balance), in each case immediately prior to
                                    the Distribution Date.
 
                                    The "Class IA-3 Liquidation Amount" is the aggregate of,
                                    for each Group I Loan which became a Liquidated Mortgage
                                    Loan during the calendar month preceding the month of
                                    the Distribution Date, the lesser of (i) the Class IA-3
                                    Percentage of the principal balance of such Mortgage
                                    Loan (exclusive of the Class IP Fraction thereof, if
                                    applicable) and (ii) the Class IA-3 Percentage on any
                                    Distribution Date occurring prior to the fifth
                                    anniversary of the first Distribution Date and the Class
                                    IA-3 Prepayment Percentage (as defined herein) on any
                                    Distribution Date thereafter, in each case, of the
                                    Liquidation Principal with respect to such Mortgage
                                    Loan.
 
                                    For a description of the Class IA-3 Prepayment
                                    Percentage, see "Description of the Certificates --
                                    Distributions of Principal -- GROUP IA PRINCIPAL
                                    DISTRIBUTION AMOUNT" herein.
 
                                    GROUP I SUBORDINATE PRINCIPAL DISTRIBUTION AMOUNT.  On
                                    each Distribution Date, an amount, up to the Group I
                                    Subordinate Principal Distribution Amount (as defined
                                    below) for such Distribution Date, will be distributed
                                    as principal to the Group IB Certificates. On each
                                    Distribution Date, except Distribution Dates on which
                                    the Subordination Level for any Class of Group IB
                                    Certificates is less than such Subordination Level as of
                                    the Cut-Off Date, each Class of Group IB Certificates
                                    will be entitled to receive its pro rata (by Class
                                    Principal Balance) share of the Group I Subordinate
                                    Principal Distribution Amount, to the extent of the
                                    Available Distribution Amount for Loan Group I remaining
                                    after distributions of interest and principal to the
                                    Group IA, Class IX, Class IP and Class R Certificates,
                                    distributions of interest and principal to all Classes
                                    of Group IB Certificates senior to such Class and
                                    distributions of interest to such Class. See
                                    "Description of the Certificates -- Priority of
                                    Distributions" herein. The relative seniority, from
                                    highest to lowest, of the Group IB Certificates shall be
                                    as follows: Class IB-1, Class IB-2, Class IB-3, Class
                                    IB-4, Class IB-5 and Class IB-6.
 
                                    The "Group I Subordinate Principal Distribution Amount"
                                    for any Distribution Date will be equal to the sum of
                                    (I) the excess of (A) the sum of (i) the Group I
                                    Subordinate Percentage of the Principal Payment Amount
                                    for Loan Group I (exclusive of the portion thereof
                                    attributable to the Class IP Principal Distribution
                                    Amount), (ii) the Group I Subordinate Prepayment
                                    Percentage of the Principal Prepayment Amount for Loan
</TABLE>
 
                                      S-24
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    Group I (exclusive of the portion thereof attributable
                                    to the Class IP Principal Distribution Amount) and (iii)
                                    the Group I Subordinate Liquidation Amount over (B) the
                                    amounts required to be distributed to the Class IP
                                    Certificates pursuant to clause (iv) of paragraph (a)
                                    under "Description of the Certificates -- Priority of
                                    Distributions" on such Distribution Date and (II) any
                                    payments received by Loan Group I with respect to any
                                    transfer of principal owing to it from Loan Group II.
 
                                    The "Group I Subordinate Liquidation Amount" will equal
                                    the excess, if any, of the aggregate Liquidation
                                    Principal for all Group I Loans which became Liquidated
                                    Mortgage Loans during the calendar month preceding the
                                    month of the Distribution Date, over the Group IA
                                    Liquidation Amount for such Distribution Date.
 
                                    The "Group I Subordinate Prepayment Percentage" for any
                                    Distribution Date will equal the excess of 100% over the
                                    Group IA Prepayment Percentage; PROVIDED, HOWEVER, that
                                    if the Class Principal Balance of the Group IA and Class
                                    R Certificates has been reduced to zero, then the Group
                                    I Subordinate Prepayment Percentage will equal 100%.
 
                                    The rights of the holders of the Group IB Certificates
                                    to receive distributions of interest and principal are
                                    subordinated to the rights of the holders of the Group
                                    IA, Class IX, Class IP and Class R Certificates to
                                    receive scheduled distributions of interest and
                                    principal. See "Description of the Certificates --
                                    Subordination and Allocation of Losses" herein.
 
                                    Group II Certificate Principal Distributions
 
                                    PO COMPONENT PRINCIPAL DISTRIBUTION AMOUNT.  On each
                                    Distribution Date, the PO Component of the Class IIA-1
                                    Certificates will receive a portion of the Available
                                    Distribution Amount for Loan Group II attributable to
                                    principal received on or in respect of any Group II Loan
                                    with a Pass-Through Rate of less than 7.500% (a "PO
                                    Component Mortgage Loan"), equal to the amount of such
                                    principal so attributable multiplied by a fraction, the
                                    numerator of which is 7.500% minus the Pass-Through Rate
                                    on such PO Component Mortgage Loan and the denominator
                                    of which is 7.500% (the "PO Component Fraction"). In
                                    addition, on each Distribution Date for so long as any
                                    Class of Group IIB Certificates remains outstanding, the
                                    PO Component will also be allocated principal, to the
                                    extent of amounts available to pay the Group II
                                    Subordinate Principal Distribution Amount (without
                                    regard to clauses (I)(B) and (II) of such definition) on
                                    such Distribution Date, in an amount generally equal to
                                    (i) the PO Component Fraction of any loss on a PO
                                    Component Mortgage Loan other than a Special Hazard Loss
                                    in excess of the Special Hazard Coverage, a Fraud Loss
                                    in excess of the Group II Fraud Coverage or a Bankruptcy
                                    Loss in excess of the Group II Bankruptcy Coverage
                                    (each, as defined herein) and (ii) the sum of amounts,
                                    if any, by which the
</TABLE>
 
                                      S-25
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    foregoing amount on each prior Distribution Date
                                    exceeded the amount actually distributed in respect
                                    thereof on such prior Distribution Dates and not
                                    subsequently distributed; PROVIDED, that such payments
                                    in respect of losses shall not cause a further reduction
                                    of the outstanding Component Balance of the PO Component
                                    of the Class IIA-1 Certificates. The aggregate of the
                                    amounts payable to the PO Component of the Class IIA-1
                                    Certificates described in this paragraph are referred to
                                    herein as the "PO Component Principal Distribution
                                    Amount".
 
                                    GROUP IIA PRINCIPAL DISTRIBUTION AMOUNT. On each
                                    Distribution Date prior to the Group II Credit Support
                                    Depletion Date, an amount, up to the amount of the Group
                                    IIA Principal Distribution Amount (as defined below) for
                                    such Distribution Date, will be distributed as principal
                                    to the following Classes of Group IIA Certificates in
                                    the following order of priority:
 
                                    (i) first, to the Class IIA-4 Certificates, an amount,
                                    up to the amount of the Class IIA-4 Principal
                                        Distribution Amount (as defined below) for such
                                        Distribution Date, until the Class IIA-4 Principal
                                        Balance has been reduced to zero;
 
                                    (ii) second, to the Class IIA-2 Certificates, the
                                    portion of the Group IIA Principal Distribution Amount
                                         remaining after the distribution described above,
                                         to the extent necessary to reduce the Class IIA-2
                                         Principal Balance to its Planned Principal Balance
                                         for such Distribution Date;
 
                                    (iii) third, to the Class IIA-6 Certificates, the
                                    portion of the Group IIA Principal Distribution Amount
                                          remaining after the distributions described above,
                                          to the extent necessary to reduce the Class IIA-6
                                          Principal Balance to its Planned Principal Balance
                                          for such Distribution Date;
 
                                    (iv) fourth, to the Class IIA-7 Certificates, the
                                    portion of the Group IIA Principal Distribution Amount
                                         remaining after the distributions described above,
                                         to the extent necessary to reduce the Class IIA-7
                                         Principal Balance to its Planned Principal Balance
                                         for such Distribution Date;
 
                                    (v) fifth, to the PAC Component of the Class IIA-1
                                        Certificates, the portion of the Group IIA Principal
                                        Distribution Amount remaining after the
                                        distributions described above, to the extent
                                        necessary to reduce the Component Balance of such
                                        PAC Component to its Planned Principal Balance for
                                        such Distribution Date;
 
                                    (vi) sixth, to the Class IIA-3 Certificates, the portion
                                    of the Group IIA Principal Distribution Amount remaining
                                         after the distributions described above, to the
                                         extent necessary to reduce the Class IIA-3
                                         Principal Balance
</TABLE>
 
                                      S-26
<PAGE>
 
<TABLE>
<S>                                 <C>
                                         to its Targeted Principal Balance for such
                                         Distribution Date;
 
                                    (vii) seventh, to the TAC Component of the Class IIA-1
                                          Certificates, the portion of the Group IIA
                                          Principal Distribution Amount remaining after the
                                          distributions described above, to the extent
                                          necessary to reduce the Component Balance of such
                                          TAC Component to its Targeted Principal Balance
                                          for such Distribution Date;
 
                                    (viii) eighth, to the Class IIA-5 Certificates, the
                                    portion of the Group IIA Principal Distribution Amount
                                           remaining after the distributions described
                                           above, until the Class IIA-5 Principal Balance
                                           has been reduced to zero;
 
                                    (ix) ninth, to the Class IIA-3 Certificates, the portion
                                    of the Group IIA Principal Distribution Amount remaining
                                         after the distributions described above, until the
                                         Class IIA-3 Principal Balance has been reduced to
                                         zero;
 
                                    (x) tenth, to the TAC Component of the Class IIA-1
                                        Certificates, the portion of the Group IIA Principal
                                        Distribution Amount remaining after the
                                        distributions described above, until the Component
                                        Balance of such TAC Component has been reduced to
                                        zero;
 
                                    (xi) eleventh, to the Class IIA-2 Certificates, the
                                    portion of the Group IIA Principal Distribution Amount
                                         remaining after the distributions described above,
                                         until the Class IIA-2 Principal Balance has been
                                         reduced to zero;
 
                                    (xii) twelfth, to the Class IIA-6 Certificates, the
                                    portion of the Group IIA Principal Distribution Amount
                                          remaining after the distributions described above,
                                          until the Class IIA-6 Principal Balance has been
                                          reduced to zero;
 
                                    (xiii) thirteenth, to the Class IIA-7 Certificates, the
                                    portion of the Group IIA Principal Distribution Amount
                                           remaining after the distributions described
                                           above, until the Class IIA-7 Principal Balance
                                           has been reduced to zero;
 
                                    (xiv) fourteenth, to the PAC Component of the Class
                                    IIA-1 Certificates, the portion of the Group IIA
                                          Principal Distribution Amount remaining after the
                                          distributions described above, until the Component
                                          Balance of such PAC Component has been reduced to
                                          zero;
 
                                    (xv) fifteenth, to the Class IIA-4 Certificates, the
                                    portion of the Group IIA Principal Distribution Amount
                                         remaining after the distributions described above,
                                         until the Class IIA-4 Principal Balance has been
                                         reduced to zero;
</TABLE>
 
                                      S-27
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    The "Group IIA Principal Distribution Amount" for any
                                    Distribution Date will equal the sum of (i) the Group
                                    IIA Percentage (as defined below) of the Principal
                                    Payment Amount for Loan Group II (exclusive of the
                                    portion thereof attributable to the PO Component
                                    Principal Distribution Amount), (ii) the Group IIA
                                    Prepayment Percentage (as defined below) of the
                                    Principal Prepayment Amount for Loan Group II (exclusive
                                    of the portion thereof attributable to the PO Component
                                    Principal Distribution Amount), and (iii) the Group IIA
                                    Liquidation Amount (as defined below).
 
                                    The "Group IIA Percentage" for any Distribution Date
                                    will equal the sum of the Class Principal Balances of
                                    the Group IIA Certificates (less the Component Balance
                                    of the PO Component of the Class IIA-1 Certificates)
                                    divided by the aggregate Class Principal Balance of the
                                    Group II Certificates (less the Component Balance of the
                                    PO Component of the Class IIA-1 Certificates), in each
                                    case immediately prior to the Distribution Date.
 
                                    The "Group IIA Liquidation Amount" is the aggregate of,
                                    for each Group II Loan which became a Liquidated
                                    Mortgage Loan during the calendar month preceding the
                                    month of the Distribution Date, the lesser of (i) the
                                    Group IIA Percentage of the principal balance of such
                                    Mortgage Loan (exclusive of the PO Component Fraction
                                    thereof, with respect to any PO Component Mortgage Loan)
                                    and (ii) the Group IIA Prepayment Percentage of the
                                    Liquidation Principal with respect to such Mortgage
                                    Loan.
 
                                    The "Group II Subordinate Percentage" for any
                                    Distribution Date will equal the excess of 100% over the
                                    Group IIA Percentage for such date. The Group IIA
                                    Percentage and the Group II Subordinate Percentage as of
                                    the Cut-Off Date will be approximately 95.23% and 4.77%,
                                    respectively.
 
                                    The "Class IIA-4 Principal Distribution Amount" for any
                                    Distribution Date will equal the sum of (i) the Class
                                    IIA-4 Percentage (as defined below) of the Principal
                                    Payment Amount for Loan Group II (exclusive of the
                                    portion thereof attributable to the PO Component
                                    Principal Distribution Amount), (ii) the Class IIA-4
                                    Prepayment Percentage (as defined herein) of the
                                    Principal Prepayment Amount for Loan Group II (exclusive
                                    of the portion thereof attributable to the PO Component
                                    Principal Distribution Amount) and (iii) the Class IIA-4
                                    Liquidation Amount (as defined below).
 
                                    The "Class IIA-4 Percentage" for any Distribution Date
                                    will equal the Class IIA-4 Principal Balance divided by
                                    the aggregate Class Principal Balance of the Group II
                                    Certificates (less the Component Balance of the PO
                                    Component of the Class IIA-1 Certificates), in each case
                                    immediately prior to the Distribution Date.
</TABLE>
 
                                      S-28
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    The "Class IIA-4 Liquidation Amount" is the aggregate
                                    of, for each Group II Loan which became a Liquidated
                                    Mortgage Loan during the calendar month preceding the
                                    month of the Distribution Date, the lesser of (i) the
                                    Class IIA-4 Percentage of the principal balance of such
                                    Mortgage Loan (exclusive of the PO Component Fraction
                                    thereof, if applicable) and (ii) the Class IIA-4
                                    Percentage on any Distribution Date occurring prior to
                                    the fifth anniversary of the first Distribution Date,
                                    and the Class IIA-4 Prepayment Percentage (as defined
                                    herein) on any Distribution Date thereafter, in each
                                    case, of the Liquidation Principal with respect to such
                                    Mortgage Loan.
 
                                    For a description of the Class IIA-4 Prepayment
                                    Percentage, see "Description of the Certificates --
                                    Distributions of Principal -- GROUP IIA PRINCIPAL
                                    DISTRIBUTION AMOUNT" herein.
 
                                    GROUP II SUBORDINATE PRINCIPAL DISTRIBUTION AMOUNT.  On
                                    each Distribution Date, an amount, up to the Group II
                                    Subordinate Principal Distribution Amount (as defined
                                    below) for such Distribution Date, will be distributed
                                    as principal to the Group IIB Certificates. On each
                                    Distribution Date, except Distribution Dates on which
                                    the Subordination Level for any Class of Group IIB
                                    Certificates is less than such Subordination Level as of
                                    the Cut-Off Date, each Class of Group IIB Certificates
                                    will be entitled to receive its pro rata (by Class
                                    Principal Balance) share of the Group II Subordinate
                                    Principal Distribution Amount, to the extent of the
                                    Available Distribution Amount for Loan Group II
                                    remaining after distributions of interest and principal
                                    to the Group IIA and Class IIX Certificates,
                                    distributions of interest and principal to all Classes
                                    of Group IIB Certificates senior to such Class and
                                    distributions of interest to such Class. See
                                    "Description of the Certificates -- Priority of
                                    Distributions" herein. The relative seniority, from
                                    highest to lowest, of the Group IIB Certificates shall
                                    be as follows: Class IIB-1, Class IIB-2, Class IIB-3,
                                    Class IIB-4, Class IIB-5 and Class IIB-6.
 
                                    The "Group II Subordinate Principal Distribution Amount"
                                    for any Distribution Date will be equal to the sum of
                                    (I) the excess of (A) the sum of (i) the Group II
                                    Subordinate Percentage of the Principal Payment Amount
                                    for Loan Group II (exclusive of the portion thereof
                                    attributable to the PO Component Principal Distribution
                                    Amount), (ii) the Group II Subordinate Prepayment
                                    Percentage of the Principal Prepayment Amount for Loan
                                    Group II (exclusive of the portion thereof attributable
                                    to the PO Component Principal Distribution Amount) and
                                    (iii) the Group II Subordinate Liquidation Amount over
                                    (B) the amounts required to be distributed to the PO
                                    Component of the Class IIA-1 Certificates pursuant to
                                    clause (iv) of paragraph (b) under "Description of the
                                    Certificates -- Priority of Distributions" on such
                                    Distribution Date and (II) any payments received by Loan
                                    Group II with respect to any transfer of principal owing
                                    to it from Loan Group I.
</TABLE>
 
                                      S-29
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    The "Group II Subordinate Liquidation Amount" will equal
                                    the excess, if any, of the aggregate Liquidation
                                    Principal for all Group II Loans which became Liquidated
                                    Mortgage Loans during the calendar month preceding the
                                    month of the Distribution Date, over the Group IIA
                                    Liquidation Amount for such Distribution Date.
 
                                    The "Group II Subordinate Prepayment Percentage" for any
                                    Distribution Date will equal the excess of 100% over the
                                    Group IIA Prepayment Percentage; PROVIDED, HOWEVER, that
                                    if the Class Principal Balance of the Group IIA
                                    Certificates (other than the Component Balance of the PO
                                    Component of the Class IIA-1 Certificates) has been
                                    reduced to zero, then the Group II Subordinate
                                    Prepayment Percentage will equal 100%.
 
                                    The rights of the holders of the Group IIB Certificates
                                    to receive distributions of interest and principal are
                                    subordinated to the rights of the holders of the Group
                                    IIA Certificates and Class IIX Certificates to receive
                                    scheduled distributions of interest and principal. See
                                    "Description of the Certificates -- Subordination and
                                    Allocation of Losses" herein.
 
                                    General
 
                                    For any Distribution Date and for any Loan Group, the
                                    "Principal Payment Amount" is the sum, with respect to
                                    the Mortgage Loans in such Loan Group, of (i) scheduled
                                    principal payments on the Mortgage Loans due on the
                                    related Due Date, (ii) the principal portion of
                                    repurchase proceeds received with respect to any
                                    Mortgage Loan which was repurchased as permitted or
                                    required by the Pooling Agreement during the calendar
                                    month preceding the month of the Distribution Date and
                                    (iii) any other unscheduled payments of principal which
                                    were received from the Mortgage Loans during the
                                    preceding calendar month, other than Payoffs,
                                    Curtailments or Liquidation Principal. For any
                                    Distribution Date and for any Loan Group, the "Principal
                                    Prepayment Amount" is the sum, with respect to the
                                    Mortgage Loans in such Loan Group, of (i) all
                                    Curtailments from the Mortgage Loans which were received
                                    during the preceding calendar month and (ii) all Payoffs
                                    from the Mortgage Loans received from the 15th day of
                                    the month immediately prior to the month of such
                                    Distribution Date through the 14th day of the month of
                                    such Distribution Date (except for Payoffs received from
                                    the Cut-Off Date through April 14, 1997, which will be
                                    passed through to holders of Certificates on the May
                                    1997 Distribution Date). Except as described herein
                                    under "Description of the Certificates -- Distributions
                                    of Principal -- CROSS-COLLATERALIZATION", principal
                                    distributions to the Group I Certificates will be based
                                    on the Principal Payment Amount, Principal Prepayment
                                    Amount and Liquidation Principal for the Group I Loans
                                    and principal distributions to the Group II Certificates
                                    will be based on the Principal Payment Amount, Principal
                                    Prepayment Amount and Liquidation Principal for the
                                    Group II Loans.
</TABLE>
 
                                      S-30
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    The "Group IA Prepayment Percentage" and "Group IIA
                                    Prepayment Percentage" for any Distribution Date
                                    occurring until the fifth anniversary of the first
                                    Distribution Date will equal 100%. Thereafter, the Group
                                    IA and Group IIA Prepayment Percentages will, except as
                                    described herein, be subject to gradual reduction as
                                    described in "Description of the Certificates --
                                    Distributions of Principal" herein. This will have the
                                    effect of accelerating the amortization of the Senior
                                    Certificates (other than the Class IP Certificates, the
                                    PO Component of the Class IIA-1 Certificates and the
                                    Lockout Certificates), subject to the priorities
                                    described in "Description of the Certificates --
                                    Distributions of Principal" herein, while increasing the
                                    proportionate interest in the Trust evidenced by the
                                    Lockout Certificates and Class B Certificates.
                                    Allocating a proportionately greater share of principal
                                    prepayments with respect to the Mortgage Loans in a Loan
                                    Group to the related Class A Certificates (other than
                                    the Lockout Certificates and the PO Component of the
                                    Class IIA-1 Certificates) is intended to enhance the
                                    likelihood that holders of such Certificates will be
                                    paid the full amount of principal to which they are
                                    entitled. See "Description of the Certificates --
                                    Subordination and Allocation of Losses" herein.
 
Subordination and Allocation of
  Losses..........................  The Class B Certificates of each Certificate Group will
                                    be subordinate in right of payment to and provide credit
                                    support to the Senior Certificates of such Certificate
                                    Group, the Junior Subordinate Certificates of each
                                    Certificate Group will be subordinate in right of
                                    payment to and provide credit support to the Senior
                                    Subordinate Certificates of such Certificate Group and
                                    each Class of Senior Subordinate Certificates in each
                                    Certificate Group will be subordinate in right of
                                    payment to and provide credit support to each Class of
                                    Senior Subordinate Certificates of such Certificate
                                    Group with a lower numerical Class designation. The
                                    support provided by the Class B Certificates of each
                                    Certificate Group is intended to enhance the likelihood
                                    of regular receipt by the Senior Certificates of such
                                    Certificate Group of the full amount of the monthly
                                    distributions of interest (except the Class IP
                                    Certificates and the PO Component of the Class IIA-1
                                    Certificates, which are not entitled to interest) and
                                    principal (except the Class X Certificates and the IO
                                    Component of the Class IIA-1 Certificates, which are not
                                    entitled to principal) to which they are entitled and to
                                    afford such Certificates protection against certain
                                    losses. The protection afforded to the Senior
                                    Certificates of each Certificate Group by the Class B
                                    Certificates of such Certificate Group will be
                                    accomplished by the preferential right on each
                                    Distribution Date of such Senior Certificates to receive
                                    distributions of interest (except the Class IP
                                    Certificates and PO Component of the Class IIA-1
                                    Certificates) and principal (except the Class X
                                    Certificates and IO Component of the Class IIA-1
                                    Certificates) prior to distributions of interest or
</TABLE>
 
                                      S-31
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    principal to such Class B Certificates. The support
                                    provided by the Junior Subordinate Certificates of each
                                    Certificate Group to the Senior Subordinate Certificates
                                    of such Certificate Group is intended to enhance the
                                    likelihood of regular receipt by such Senior Subordinate
                                    Certificates of the full amount of monthly distributions
                                    of interest and principal to which they are entitled and
                                    to afford such Certificateholders protection against
                                    certain losses. The protection afforded to the Senior
                                    Subordinate Certificates of each Certificate Group by
                                    the Junior Subordinate Certificates of such Certificate
                                    Group will be accomplished by the preferential right on
                                    each Distribution Date of such Senior Subordinate
                                    Certificates to receive distributions of interest and
                                    principal, prior to distributions of interest and
                                    principal to such Junior Subordinate Certificates.
                                    Except for all Special Hazard Losses and for Fraud
                                    Losses and Bankruptcy Losses in excess of the designated
                                    amounts of Group I Fraud Coverage and Group I Bankruptcy
                                    Coverage (each, as defined herein), any loss realized
                                    with respect to a Group I Loan will be allocated among
                                    the Group I Certificates and the Class R Certificates
                                    (i) for losses allocable to principal (a) first, to the
                                    Group I Junior Subordinate Certificates, until the
                                    aggregate of the Class Principal Balances thereof has
                                    been reduced to zero, (b) second, to the Class IB-3
                                    Certificates, until the Class IB-3 Principal Balance has
                                    been reduced to zero, (c) third, to the Class IB-2
                                    Certificates, until the Class IB-2 Principal Balance has
                                    been reduced to zero, (d) fourth, to the Class IB-1
                                    Certificates, until the Class IB-1 Principal Balance has
                                    been reduced to zero and (e) fifth, to the Group IA and
                                    Class R Certificates, pro rata, according to their Class
                                    Principal Balances (or Component Balances in the case of
                                    the PAC Component and Companion Component of the Class
                                    IA-1 Certificates and the PAC Component and TAC
                                    Component of the Class IA-2 Certificates) in reduction
                                    of their respective Class Principal or Component
                                    Balances, as applicable, PROVIDED, HOWEVER, that if the
                                    loss is recognized with respect to a Class IP Mortgage
                                    Loan, the Class IP Fraction of such loss will first be
                                    allocated to the Class IP Certificates and the remainder
                                    of such loss will be allocated as described above in
                                    this clause (i); and (ii) for losses allocable to
                                    interest (a) first, to the Group I Junior Subordinate
                                    Certificates, in reduction of accrued but unpaid
                                    interest thereon and then in reduction of the Class
                                    Principal Balances of the Classes of Group I Junior
                                    Subordinate Certificates, (b) second, to the Class IB-3
                                    Certificates, in reduction of accrued but unpaid
                                    interest thereon and then in reduction of the Class IB-3
                                    Principal Balance, (c) third, to the Class IB-2 Certifi-
                                    cates, in reduction of accrued but unpaid interest
                                    thereon and then in reduction of the Class IB-2
                                    Principal Balance, (d) fourth, to the Class IB-1
                                    Certificates, in reduction of accrued but unpaid
                                    interest thereon and then in reduction of the Class IB-1
                                    Principal Balance and (e) fifth, to the Group IA, Class
                                    IX and Class R Certificates, pro rata according to
                                    accrued but unpaid interest thereon and then pro rata
                                    according to their Class Principal Balances (or
                                    Component Balances in the case of the PAC
</TABLE>
 
                                      S-32
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    Component and Companion Component of the Class IA-1 Cer-
                                    tificates and the PAC Component and TAC Component of the
                                    Class IA-2 Certificates) in reduction of their
                                    respective Class Principal or Component Balances, as
                                    applicable.
                                    Except for all Special Hazard Losses and for Fraud
                                    Losses and Bankruptcy Losses in excess of the designated
                                    amounts of Group II Fraud Coverage and Group II
                                    Bankruptcy Coverage (each, as defined herein), any loss
                                    realized with respect to a Group II Loan will be
                                    allocated among the Group II Certificates (i) for losses
                                    allocable to principal (a) first, to the Group II Junior
                                    Subordinate Certificates, until the aggregate of the
                                    Class Principal Balances thereof has been reduced to
                                    zero, (b) second, to the Class IIB-3 Certificates, until
                                    the Class IIB-3 Principal Balance has been reduced to
                                    zero, (c) third, to the Class IIB-2 Certificates, until
                                    the Class IIB-2 Principal Balance has been reduced to
                                    zero, (d) fourth, to the Class IIB-1 Certificates, until
                                    the Class IIB-1 Principal Balance has been reduced to
                                    zero and (e) fifth, to the Group IIA Certificates, pro
                                    rata, according to their Class Principal Balances (or
                                    Component Balances in the case of the PAC Component and
                                    TAC Component of the Class IIA-1 Certificates) in
                                    reduction of their respective Class Principal or
                                    Component Balances, as applicable; PROVIDED, HOWEVER,
                                    that if the loss is recognized with respect to a PO
                                    Component Mortgage Loan, the PO Component Fraction of
                                    such loss will first be allocated to the PO Component of
                                    the Class IIA-1 Certificates and the remainder of such
                                    loss will be allocated as described above in this clause
                                    (i); and (ii) for losses allocable to interest (a)
                                    first, to the Group II Junior Subordinate Certificates,
                                    in reduction of accrued but unpaid interest thereon and
                                    then in reduction of the Class Principal Balances of the
                                    Classes of Group II Junior Subordinate Certificates, (b)
                                    second, to the Class IIB-3 Certificates, in reduction of
                                    accrued but unpaid interest thereon and then in
                                    reduction of the Class IIB-3 Principal Balance, (c)
                                    third, to the Class IIB-2 Certificates, in reduction of
                                    accrued but unpaid interest thereon and then in
                                    reduction of the Class IIB-2 Principal Balance, (d)
                                    fourth, to the Class IIB-1 Certificates, in reduction of
                                    accrued but unpaid interest thereon and then in
                                    reduction of the Class IIB-1 Principal Balance and (e)
                                    fifth, to the Group IIA (other than the PO Component of
                                    the Class IIA-1 Certificates) and Class IIX Cer-
                                    tificates, pro rata according to accrued but unpaid
                                    interest thereon and then pro rata according to their
                                    Class Principal Balances (or Component Balances in the
                                    case of the PAC Component and TAC Component of the Class
                                    IIA-1 Certificates) in reduction of their respective
                                    Class Principal or Component Balances, as applicable.
                                    Special Hazard Losses incurred on a Mortgage Loan in
                                    either Loan Group up to the Special Hazard Coverage will
                                    be allocated (i) first, to the Lowest Class of
                                    Subordinate Certificates outstanding, regardless of
                                    Certificate Group, or, if there are both Class IB and
                                    Class IIB Certificates outstanding with the
</TABLE>
 
                                      S-33
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    same lowest rating, then pro rata to such Lowest Classes
                                    according to their respective Class Principal Balances,
                                    (ii) second, to the next Lowest Class or Classes of
                                    Subordinate Certificates outstanding, in the manner
                                    described in clause (i) above until the Class Principal
                                    Balances of all of the Subordinate Certificates have
                                    been reduced to zero, and (iii) third, to the Senior
                                    Certificates related to the Loan Group in which the loss
                                    occurred, by Pro Rata Allocation (as defined below);
                                    PROVIDED, HOWEVER, that in the event any Special Hazard
                                    Loss is incurred with respect to a Class IP Mortgage
                                    Loan or a PO Component Mortgage Loan, the applicable
                                    Class IP Fraction or PO Component Fraction of such loss
                                    will first be allocated to such Class IP Mortgage Loan
                                    or PO Component Mortgage Loan and the remainder of such
                                    loss will be allocated as described above. See
                                    "Decription of the Certificates --
                                    Cross-Collateralization" herein.
                                    Special Hazard Losses, Fraud Losses and Bankruptcy
                                    Losses for Mortgage Loans in a Loan Group in excess of
                                    the applicable coverage will be allocated to all
                                    outstanding Classes of Certificates in the related
                                    Certificate Group by Pro Rata Allocation (as defined
                                    below). Each of the coverages for such losses may be
                                    reduced periodically, as described herein. See
                                    "Description of the Certificates -- Subordination and
                                    Allocation of Losses" herein.
                                    The allocation of the principal portion of losses
                                    relating to a Mortgage Loan in a given Loan Group to all
                                    Classes of Certificates in the related Certificate Group
                                    (other than the Class IP Certificates in the case of a
                                    Group I Loan and the PO Component of the Class IIA-1
                                    Certificates in the case of a Group II Loan) pro rata
                                    according to their respective Class Principal or
                                    Component Balances (except if the loss is recognized
                                    with respect to a Class IP Mortgage Loan or PO Component
                                    Mortgage Loan, in which event the Class IP Fraction or
                                    PO Component Fraction, of such loss will first be
                                    allocated to the Class IP Certificates or PO Component
                                    of the Class IIA-1 Certificates, respectively, and the
                                    remainder of such loss will be allocated as described
                                    above), and the allocation of the interest portion of
                                    such losses to the Certificates in the related
                                    Certificate Group pro rata according to the amount of
                                    interest accrued on each such Class or Component (other
                                    than the Class IP Certificates in the case of a Group I
                                    Loan and the PO Component of the Class IIA-1
                                    Certificates in the case of a Group II Loan) in
                                    reduction thereof and then in reduction of their related
                                    Class Principal or Component Balances, is hereinafter
                                    referred to as "Pro Rata Allocation". For the purpose of
                                    allocating losses in Loan Group I to the outstanding
                                    Classes of Group I Certificates by Pro Rata Allocation,
                                    the Class R Certificates are deemed to be Group I
                                    Certificates.
                                    On each Distribution Date, after giving effect to the
                                    principal distributions and allocations of losses
                                    described above, if the
</TABLE>
 
                                      S-34
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    aggregate Certificate Principal Balance of all
                                    outstanding Certificates in a Certificate Group exceeds
                                    the sum of (i) the aggregate principal balance of the
                                    Mortgage Loans in the related Loan Group (giving effect
                                    for each such Mortgage Loan to all amounts of principal
                                    in respect of such Mortgage Loan that have been received
                                    or advanced and included in the Available Distribution
                                    Amount for such Loan Group, and all losses in respect of
                                    such Mortgage Loans that have been allocated to
                                    Certificates, on Distribution Dates on or before such
                                    Distribution Date) and (ii) any Transfer Balance owing
                                    to such Certificate Group, that excess will be deemed a
                                    principal loss and will be allocated to the most junior
                                    Class of Subordinate Certificates in such Certificate
                                    Group.
                                    Investors in the Senior Certificates should be aware
                                    that the coverage for Special Hazard Losses covers
                                    Mortgage Loans in both Loan Groups. Therefore, in the
                                    event Mortgage Loans in a Loan Group suffer a high level
                                    of Special Hazard Losses, it will reduce the available
                                    coverage for the Senior Certificates of both Certificate
                                    Groups and also will cause Senior Certificates of a
                                    Certificate Group to suffer losses in the event Mortgage
                                    Loans in the related Loan Group suffer such losses after
                                    the available coverage has been exhausted,
                                    notwithstanding minimal Special Hazard Losses in such
                                    Loan Group prior thereto.
                                    See also "Description of the Certificates --
                                    Distributions of Principal" herein.
Credit Enhancements...............  SUBORDINATION.  The holders of the Senior Certificates
                                    of a Certificate Group are entitled to receive
                                    distributions of interest (except, with respect to the
                                    Group I Certificates, the Class IP Certificates and,
                                    with respect to the Group II Certificates, the PO
                                    Component of the Class IIA-1 Certificates, which are not
                                    entitled to interest) and principal (except, with
                                    respect to the Group I Certificates, the Class IX
                                    Certificates and, with respect to the Group II
                                    Certificates, Class IIX Certificates and the IO
                                    Component of the Class IIA-1 Certificates, which are not
                                    entitled to principal) before distributions of interest
                                    or principal to the holders of the Class B Certificates
                                    of the related Certificate Group. No Class B
                                    Certificates of a Certificate Group will receive
                                    distributions of interest or principal on any
                                    Distribution Date until the Class or Classes in the
                                    related Certificate Group senior to such Class have
                                    received all distributions of interest and principal due
                                    on or before such Distribution Date. See "Description of
                                    the Certificates -- Priority of Distributions" herein.
                                    Losses on Mortgage Loans in a Loan Group will be
                                    allocated, in each case until the applicable Class
                                    Principal Balances have been reduced to zero, first, to
                                    the Junior Subordinate Certificates in the related
                                    Certificate Group; second, to the Class IB-3 or Class
                                    IIB-3 Certificates, as applicable; third, to the Class
                                    IB-2 or Class IIB-2 Certificates, as applicable; fourth,
                                    to the Class IB-1 or Class IIB-1 Certificates, as
                                    applicable; and fifth, to the outstanding Classes of
                                    Senior Certificates in the related Certificate Group by
                                    Pro Rata Allocation; PROVIDED, HOWEVER,
</TABLE>
 
                                      S-35
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    that only a certain specified amount of Fraud Losses and
                                    Bankruptcy Losses in a Loan Group will be allocated
                                    solely to the Class B Certificates in the related
                                    Certificate Group and only a certain specified amount of
                                    Special Hazard Losses in a Loan Group will be allocated
                                    solely to the Class B Certificates in both Certificate
                                    Groups, following which such losses will be allocated
                                    among all outstanding Classes of Certificates in the
                                    related Certificate Group by Pro Rata Allocation;
                                    PROVIDED, FURTHER, that in the event any loss is
                                    incurred with respect to a Class IP Mortgage Loan or a
                                    PO Component Mortgage Loan, the applicable Class IP
                                    Fraction or PO Component Fraction of such loss will
                                    first be allocated to such Class IP Mortgage Loan or PO
                                    Component Mortgage Loan and the remainder of such loss
                                    will be allocated as described above.
                                    See "Description of the Certificates -- Subordination
                                    and Allocation of Losses" herein.
                                    SHIFTING OF INTERESTS.  The Senior Certificates of a
                                    Certificate Group entitled to principal, other than the
                                    Lockout Certificates of such Certificate Group, will
                                    receive 100% of Principal Prepayments received with
                                    respect to the Mortgage Loans in the related Loan Group
                                    until the fifth anniversary of the first Distribution
                                    Date. During the next four years, such Senior Certifi-
                                    cates, other than the Lockout Certificates of such
                                    Certificate Group, will receive a disproportionately
                                    large, but decreasing, share of Principal Prepayments
                                    received with respect to the Mortgage Loans in the
                                    related Loan Group. This will result in an acceleration
                                    of the amortization of such Senior Certificates, other
                                    than the Lockout Certificates, subject to the priorities
                                    described in "Description of the Certificates --
                                    Distributions of Principal" herein, enhancing the
                                    likelihood that holders of such Classes of Certificates
                                    will be paid the full amount of principal to which they
                                    are entitled.
Advances..........................  With respect to each Mortgage Loan, the Master Servicer
                                    will make Advances on each Distribution Date to the
                                    Certificate Account to cover any shortfall between (i)
                                    payments scheduled to be received in respect of such
                                    Mortgage Loan and (ii) the amounts actually deposited in
                                    the Certificate Account on account of such payments;
                                    provided that the Master Servicer determines, in good
                                    faith, on such Distribution Date that such Advances will
                                    be recoverable from Insurance Proceeds, Liquidation
                                    Proceeds or other amounts received with respect to such
                                    Mortgage Loan. Advances are reimbursable to the Master
                                    Servicer from cash in the Certificate Account prior to
                                    payments to the Certificateholders if the Master
                                    Servicer determines that any such Advances previously
                                    made are not recoverable from Insurance Proceeds,
                                    Liquidation Proceeds or other amounts recoverable with
                                    respect to the applicable Mortgage Loan. See
                                    "Description of the Certificates -- Advances" herein.
Yield and Prepayment                The effective yield to maturity of each Class of
  Considerations..................  Certificates will depend upon, among other things, the
                                    price at which such Certificates are purchased, the
                                    applicable Remittance Rate, the actual characteristics
                                    of the Mortgage Loans in the related Loan
</TABLE>
 
                                      S-36
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    Group, the rate of principal payments (including
                                    Principal Prepayments) on the Mortgage Loans in the
                                    related Loan Group and the rate of liquidations on the
                                    Mortgage Loans in the related Loan Group. A higher than
                                    anticipated rate of principal payments (including
                                    Principal Prepayments) and liquidations would reduce the
                                    aggregate principal balance of the Mortgage Loans more
                                    quickly than expected, thereby reducing the aggregate
                                    interest payments with respect to such Mortgage Loans.
                                    Therefore, a higher rate of principal payments
                                    (including Principal Prepayments) and liquidations in a
                                    Loan Group could result in a lower than expected yield
                                    to maturity on related Classes of Certificates purchased
                                    at a premium. Conversely, a lower than anticipated rate
                                    of principal payments (including Principal Prepayments)
                                    and liquidations in a Loan Group could reduce the return
                                    on any related Class of Certificates purchased at a dis-
                                    count, in that payments of principal with respect to the
                                    Mortgage Loans in such Loan Group would occur later than
                                    anticipated. Except as described herein under
                                    "Description of the Certificates -- Distribution of
                                    Principal -- CROSS-COLLATERALIZATION", principal
                                    distributions to the Group I Certificates and Group II
                                    Certificates relate to principal payments on the Group I
                                    Loans and Group II Loans, respectively.
                                    The actual rate of payments of principal (including
                                    Principal Prepayments) and liquidations on the Mortgage
                                    Loans may be influenced by a variety of economic,
                                    geographic, social and other factors. In general, if
                                    interest rates generally rise above the interest rates
                                    on the Mortgage Loans, the rate of prepayment would be
                                    expected to decrease. Conversely, if prevailing interest
                                    rates fall significantly below the interest rates on the
                                    Mortgage Loans, the Mortgage Loans are likely to be
                                    subject to higher prepayment rates than if prevailing
                                    rates remain at or above the interest rates on the
                                    Mortgage Loans. See "Risk Factors" and "Yield and
                                    Prepayment Considerations" herein.
Special Yield and Prepayment
  Considerations..................  The yields to maturity on the Class X and Class IP
                                    Certificates will be extremely sensitive to the level of
                                    Principal Prepayments on the Mortgage Loans in the
                                    related Loan Group. The interest payable to the Class
                                    IX-1 Certificates is based on the weighted average of
                                    the Stripped Interest Rates of the Class IX-1 15-Year
                                    Premium Rate Mortgage Loans. The interest payable to the
                                    Class IX-2 Certificates is based on the weighted average
                                    of the Stripped Interest Rates of the Class IX-2 15-Year
                                    Premium Rate Mortgage Loans. The interest payable to the
                                    Class IIX Certificates is based on the weighted average
                                    of the Stripped Interest Rates of the 30-Year Premium
                                    Rate Mortgage Loans. The Class IX-1 15-Year Premium Rate
                                    Mortgage Loans, the Class IX-2 15-Year Premium Rate
                                    Mortgage Loans and the 30-Year Premium Rate Mortgage
                                    Loans are collectively the "Premium Rate Mortgage
                                    Loans". Therefore the yield to maturity on any Class of
                                    the Class X Certificates will generally decrease as a
                                    result of faster than expected Principal Prepayments on
                                    the related group of Premium Rate Mortgage Loans.
</TABLE>
 
                                      S-37
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    Prospective investors should fully consider the risks
                                    associated with an investment in any Class of the Class
                                    X Certificates, including the possibility that if the
                                    rate of Principal Prepayments on the related Premium
                                    Rate Mortgage Loans is rapid, such investors may not
                                    fully recoup their initial investments. Because the
                                    principal payable with respect to the Class IP
                                    Certificates (which are entitled to receive
                                    distributions of principal only) is derived from Group I
                                    Loans with Pass-Through Rates that are lower than
                                    7.000%, the yield to maturity on the Class IP Certifi-
                                    cates will be adversely affected by slower than expected
                                    prepayments of Group I Loans with Pass-Through Rates
                                    less than 7.000%. Because the interest payable on the
                                    Class IX Certificates and the principal distributable to
                                    the Class IP Certificates are derived from different
                                    groups of Mortgage Loans within Loan Group I, it is
                                    possible that faster than expected Principal Prepayments
                                    with respect to the Class IX Certificates may occur at
                                    the same time as slower than expected Principal
                                    Prepayments with respect to the Class IP Certificates.
                                    See "Yield and Prepayment Considerations" herein.
                                    Principal distributions on the Class IA-4, Class IA-5
                                    and Class IA-6 Certificates and the PAC Components of
                                    the Class IA-1 and Class IA-2 Certificates (the "Group I
                                    PACs") on any Distribution Date are generally payable
                                    based on the Planned Principal Balances set forth in
                                    Appendix A. The Planned Principal Balances for the Group
                                    I PACs were determined assuming that the prepayment rate
                                    of the Group I Loans occur each month at a constant
                                    level between approximately 105% and 300% of the Basic
                                    Prepayment Assumption (as defined herein). However, as
                                    discussed herein, actual principal distributions may
                                    deviate from the described amounts, because the actual
                                    prepayment rate of such Group I Loans each month may not
                                    occur at a constant level between approximately 105% and
                                    300% of the Basic Prepayment Assumption. If the Class
                                    IA-7 Principal Balance and the Component Balances of the
                                    Companion Component of the Class IA-1 Certificates and
                                    the TAC Component of the Class IA-2 Certificates are
                                    reduced to zero before the Class Principal Balances and
                                    Component Balances of the Group I PACs are reduced to
                                    zero, the weighted average lives of the Group I PACs
                                    will become significantly more sensitive to changes in
                                    the prepayment rate of the Group I Loans, and principal
                                    distributions thereon will be more likely to deviate
                                    from the described amounts.
                                    Principal distributions (other than principal
                                    distributions in respect of the Class IA-7 Accrual
                                    Amount) on the TAC Component of the Class IA-2
                                    Certificates (the "Group I TAC") on any Distribution
                                    Date are generally payable based on the Targeted
                                    Principal Balances set forth in Appendix B. The Targeted
                                    Principal Balances of such Component were determined
                                    assuming that the prepayment rate of the Group I Loans
                                    remains constant at 240% of the Basic Prepayment
                                    Assumption. However, as discussed herein, actual
                                    principal distributions may deviate from the described
                                    amounts, because the actual prepayment rate of
</TABLE>
 
                                      S-38
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    the Group I Loans each month may not remain constant at
                                    240% of the Basic Prepayment Assumption. If the Class
                                    IA-7 Principal Balance has been reduced to zero, the
                                    rate of principal distributions and the weighted average
                                    life of the Group I TAC will become significantly more
                                    sensitive to changes in the prepayment rate of the Group
                                    I Loans.
                                    Principal prepayments on the Group I Loans and other
                                    unscheduled payments of principal may result in
                                    principal available for distribution on a Distribution
                                    Date to the Group I PACs and Group I TAC on such
                                    Distribution Date in an amount greater than the amount
                                    necessary to reduce the applicable Class Principal and
                                    Component Balances of the Group I PACs and the Component
                                    Balance of the Group I TAC to their scheduled amounts. A
                                    percentage of such excess principal after payment of the
                                    Group I PACs will be distributed to the Companion
                                    Component of the Class IA-1 Certificates, and the
                                    remainder of such excess will be distributed to the
                                    Group I TAC to the extent of its scheduled amount, then
                                    to the Class IA-7 Certificates, until the Class IA-7
                                    Principal Balance has been reduced to zero and then to
                                    the Group I TAC until the Component Balance thereof has
                                    been reduced to zero. Any excess after all such payments
                                    will be distributed to the Group I PACs in the order by
                                    which the Group I PACs received their scheduled amounts
                                    of principal, without regard to their respective Planned
                                    Principal Balances. Accordingly, the rate of payments on
                                    the Group I Loans is expected to have a greater effect
                                    on the weighted average life of the Companion Component
                                    of the Class IA-1 Certificates and the Class IA-7
                                    Certificates, and under certain prepayment scenarios the
                                    Group I TAC, than on the weighted average lives of the
                                    Group I PACs. If the rate of Principal Prepayments and
                                    other unscheduled payments of principal causes the
                                    principal available for distribution on the Group I
                                    Certificates on any Distribution Date to be less than
                                    the amounts determined on the basis of tables as
                                    described herein to be necessary to reduce the Class
                                    Principal and Component Balances of the Group I PACs
                                    then entitled to receive principal to their respective
                                    Planned Principal Balances, the Companion Component of
                                    the Class IA-1 Certificates, the Class IA-7 Certifi-
                                    cates and the Group I TAC (other than in respect of the
                                    Class IA-7 Accrual Amount) will not receive any
                                    distributions of principal, and if the principal
                                    available for distribution to the Group I TAC is less
                                    than the amount determined on the basis of tables as
                                    described herein to be necessary to reduce the Compo-
                                    nent Balance of the Group I TAC to its Targeted
                                    Principal Balance, the Class IA-7 Certificates will not
                                    receive any distributions of principal. See "Yield and
                                    Prepayment Considerations" herein.
                                    Principal distributions on the Class IIA-2, Class IIA-6
                                    and Class IIA-7 Certificates and the PAC Component of
                                    the Class IIA-1 Certificates (the "Group II PACs") will
                                    be payable in amounts determined on the basis of the
                                    Planned Principal
</TABLE>
 
                                      S-39
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    Balances set forth in Appendix A. The Planned Principal
                                    Balances for the Group II PACs were determined assuming
                                    that the prepayment rate of the Group II Loans occur
                                    each month at a constant level between approximately
                                    100% and 500% of the Basic Prepayment Assumption.
                                    However, as discussed herein, actual principal
                                    distributions may deviate from the described amounts,
                                    because the actual prepayment rate of the Group II Loans
                                    each month may not occur at a constant level between
                                    approximately 100% and 500% of the Basic Prepayment
                                    Assumption. If the Class Principal Balance of the Class
                                    IIA-3 Certificates and the Component Balance of the TAC
                                    Component of the Class IIA-1 Certificates (the "Group II
                                    TACs") and the Class Principal Balance of the Class
                                    IIA-5 Certificates are reduced to zero before the Class
                                    Principal and Component Balances of the Group II PACs
                                    are reduced to zero, the weighted average lives of the
                                    Group II PACs will become significantly more sensitive
                                    to changes in the prepayment rate of the Group II Loans,
                                    and principal distributions thereon will be more likely
                                    to deviate from the described amounts.
                                    Principal distributions (other than principal
                                    distributions in respect of the TAC Component Accrual
                                    Amount and Class IIA-5 Accrual Amount) on the Group II
                                    TACs on any Distribution Date are payable based on the
                                    Targeted Principal Balances set forth in Appendix B. The
                                    Targeted Principal Balances were determined assuming
                                    that the prepayment rate of the Group II Loans remains
                                    constant at 250% of the Basic Prepayment Assumption.
                                    However, as discussed herein, actual principal
                                    distributions may deviate from the described amounts,
                                    because the actual prepayment rate of Group II Loans
                                    each month may not remain constant at 250% of the Basic
                                    Prepayment Assumption. If the Class IIA-5 Principal
                                    Balance has been reduced to zero, the rate of principal
                                    distributions and the weighted average life of the Group
                                    II TACs will become significantly more sensitive to
                                    changes in the prepayment rate of the Group II Loans.
                                    Principal prepayments on the Group II Loans and other
                                    unscheduled payments of principal may result in
                                    principal available for distribution to the Group II
                                    PACs and the Group II TACs on a Distribution Date in an
                                    amount greater than the amount necessary to reduce the
                                    applicable Class Principal and Component Balances of the
                                    Group II PACs and the applicable Class Principal and
                                    Component Balances of the Group II TACs to their
                                    scheduled amounts. Such excess will be distributed first
                                    to the Class IIA-5 Certificates until the Class IIA-5
                                    Principal Balance has been reduced to zero, then to the
                                    Group II TACs (first to the Class IIA-3 Certificates
                                    until the Class IIA-3 Principal Balance has been reduced
                                    to zero and then to the TAC Component of the Class IIA-1
                                    Certificates until the Component Balance of such TAC
                                    Component has been reduced to zero) and then to the
                                    Group II PACs (first to the Class IIA-2 Certificates
                                    until the Class IIA-2 Principal Balance has been reduced
                                    to zero
</TABLE>
 
                                      S-40
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    then to the Class IIA-6 Certificates until the Class
                                    IIA-6 Principal Balance has been reduced to zero, then
                                    to the Class IIA-7 Certificates until the Class IIA-7
                                    Principal Balance has been reduced to zero and then to
                                    the PAC Component of the Class IIA-1 Certificates until
                                    the Component Balance of such PAC Component has been
                                    reduced to zero). Accordingly, the rate of payments on
                                    the Group II Loans is expected to have a greater effect
                                    on the weighted average life of the Class IIA-5
                                    Certificates, and under certain prepayment scenarios the
                                    Group II TACs, than on the weighted average lives of the
                                    Group II PACs. If the rate of Principal Prepayments and
                                    other unscheduled payments of principal causes the
                                    principal available for distribution on the Group II
                                    Certificates on any Distribution Date to be less than
                                    the amounts determined on the basis of tables as
                                    described herein to be necessary to reduce the Class
                                    Principal or Component Balances of the Group II PACs
                                    then entitled to receive principal to their Planned
                                    Principal Balances and to reduce the Class Principal or
                                    Component Balances of the Group II TACs to their
                                    Targeted Principal Balances, the Class IIA-5
                                    Certificates will not receive any distribution of
                                    principal. See "Yield and Prepayment Considerations"
                                    herein.
                                    The yield to maturity on each Class of the Senior
                                    Subordinate Certificates of a Certificate Group will be
                                    extremely sensitive to realized losses on the Mortgage
                                    Loans in the related Loan Group (other than all Special
                                    Hazard Losses and Fraud Losses and Bankruptcy Losses in
                                    excess of the applicable coverage therefor provided by
                                    the Class B Certificates), because a disproportionately
                                    large amount of such losses (rather than a pro rata
                                    portion thereof) generally will be allocable to such
                                    Classes of Certificates following the reduction of the
                                    aggregate of the Class Principal Balances of the related
                                    Junior Subordinate Certificates to zero as described
                                    under "Description of the Certificates -- Subordination
                                    and Allocation of Losses" herein.
                                    LOCKOUT CERTIFICATES: Although the Lockout Certificates
                                    are Senior Certificates, the Class IA-3 and Class IIA-4
                                    Certificates will generally not be entitled to receive
                                    any distributions of Principal Prepayments until May
                                    2002. Therefore, the Class IA-3 and Class IIA-4
                                    Certificates will not be entitled to receive the
                                    disproportionate allocation of Principal Prepayments in
                                    the related Loan Group that the other Senior
                                    Certificates in the same Certificate Group are entitled
                                    to receive.
</TABLE>
 
                                      S-41
<PAGE>
 
<TABLE>
<S>                                 <C>
Ratings...........................  It is a condition to the issuance of the Offered
                                    Certificates that the Class A Certificates and Class R
                                    Certificates each be rated "AAA" by Standard & Poor's, a
                                    division of The McGraw-Hill Companies, Inc. ("S&P") and
                                    by Duff & Phelps Credit Rating Co. ("DCR"), that the
                                    Class X and Class IP Certificates each be rated "AAAr"
                                    by S&P and "AAA" by DCR and that the Class IB-1 and
                                    Class IIB-1 Certificates be rated not less than "AA" by
                                    DCR, the Class IB-2 and Class IIB-2 Certificates be
                                    rated not less than "A" by DCR and the Class IB-3 and
                                    Class IIB-3 Certificates be rated not less than "BBB" by
                                    DCR. See "Certificate Ratings", "Risk Factors" and
                                    "Yield and Prepayment Considerations" herein. The
                                    ratings on the Offered Certificates address the
                                    likelihood of the receipt by holders of Offered
                                    Certificates of all distributions with respect to the
                                    underlying Mortgage Loans to which they are entitled and
                                    do not address the likely actual rate of Principal
                                    Prepayments, which rate could, if different than
                                    originally anticipated, adversely affect the yield
                                    realized by Certificateholders or cause the Class X
                                    Certificateholders to fail to recoup their underlying
                                    investments.
Last Scheduled Distribution         The Last Scheduled Distribution Date for all Classes of
  Date............................  Certificates is May 25, 2027, which is the Distribution
                                    Date in the month after the scheduled maturity date for
                                    the latest maturing Mortgage Loan in the Mortgage Pool.
                                    The actual rate of principal payments on the
                                    Certificates will depend on the rate of payments of
                                    principal (including Principal Prepayments) on the
                                    Mortgage Loans which, in turn, may be influenced by a
                                    variety of economic, geographic and social factors, as
                                    well as the level of prevailing interest rates. No
                                    assurance can be given as to the actual payment
                                    experience on the Mortgage Loans. See "Description of
                                    the Certificates -- Last Scheduled Distribution Date"
                                    and "Yield and Prepayment Considerations" herein.
Legal Investment..................  As of the date of their issuance, the Offered
                                    Certificates, other than the Class IB-2, Class IB-3,
                                    Class IIB-2 and Class IIB-3 Certificates, will
                                    constitute "mortgage related securities" for purposes of
                                    the Secondary Mortgage Market Enhancement Act of 1984
                                    ("SMMEA"). SMMEA provides that states may override its
                                    provisions on legal investment and restrict or condition
                                    investment in mortgage related securities by taking
                                    statutory action prior to October 4, 1991. Certain
                                    states have enacted legislation which has overridden the
                                    provisions of SMMEA. See "Certain Legal Investment
                                    Aspects" herein.
                                    Institutions whose investment activities are subject to
                                    review by certain regulatory authorities may be or may
                                    become subject to restrictions on investment in the
                                    Offered Certificates, and such restrictions may be
                                    retroactively imposed. The Federal Financial
                                    Institutions Examination Council, the Federal Deposit
                                    Insurance Corporation, the Office of the Comptroller of
                                    the Currency, the Board of Governors of the Federal
                                    Reserve System, the Office of Thrift Supervision and the
                                    National Credit
</TABLE>
 
                                      S-42
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    Union Administration have adopted guidelines, and have
                                    proposed policies, regarding the suitability of
                                    investments in various types of derivative
                                    mortgage-backed securities, including securities such as
                                    the Offered Certificates. In addition, several states
                                    have adopted or are considering regulations that would
                                    prohibit regulated institutions subject to their
                                    jurisdiction from holding mortgage-backed securities
                                    such as the Offered Certificates, including such
                                    securities previously purchased. Investors should
                                    consult their own legal advisors in determining whether
                                    and to what extent the Offered Certificates constitute
                                    legal investments for such investors.
ERISA Considerations..............  See "ERISA Considerations" herein and in the Prospectus.
Certain Federal Income Tax
  Consequences....................  For federal income tax purposes, the Company will cause
                                    an election to be made to treat the Trust as a "real
                                    estate mortgage investment conduit" (a "REMIC"). The
                                    certificates issued by the Trust, other than the Class R
                                    Certificates, will be designated as REMIC regular
                                    interests. As REMIC regular interests, such certificates
                                    will generally be treated as debt for federal income tax
                                    purposes. Certificateholders will be required to include
                                    in income all interest and original issue discount
                                    ("OID") on such certificates in accordance with the
                                    accrual method of accounting regardless of the
                                    certificateholders' usual methods of accounting. For
                                    federal income tax purposes, the Class R Certificates
                                    will be the "residual interest" in the Trust.
                                    The Class IA-1, Class IA-2, Class IA-7, Class IX-1,
                                    Class IX-2, Class IP, Class IIA-5 and Class IIX
                                    Certificates will, and the Class IA-5, Class IA-6, Class
                                    IB-1, Class IB-2, Class IB-3, Class IIA-3, Class IIA-6,
                                    Class IIA-7, Class IIB-1, Class IIB-2 and Class IIB-3
                                    Certificates may, be treated as having been issued with
                                    OID for federal income tax purposes. Certain Classes of
                                    Certificates may be treated for federal income tax
                                    purposes as having been issued at a premium. The
                                    prepayment assumption that will be used in determining
                                    the rate of accrual of market discount and premium, if
                                    any, for federal income tax purposes is 240% of the
                                    Basic Prepayment Assumption for Loan Group I and 250% of
                                    the Basic Prepayment Assumption for Loan Group II as
                                    described herein under "Yield and Prepayment
                                    Considerations". The Basic Prepayment Assumption
                                    represents an assumed annual rate of prepayment relative
                                    to the then outstanding principal balance of a pool of
                                    mortgage loans which increases incrementally each month
                                    after origination until the 30th month after
                                    origination, when the rate remains constant at 6% per
                                    annum. No representation is made that the Mortgage Loans
                                    will prepay at any given percentage of the Basic
                                    Prepayment Assumption.
                                    If actual prepayments differ sufficiently from the
                                    prepayment assumption, the calculation of OID for
                                    certain Classes of Offered Certificates might produce a
                                    negative number for certain accrual periods. In such
                                    event, Certificateholders will not be entitled to a
                                    deduction for such amount, but will be required
</TABLE>
 
                                      S-43
<PAGE>
 
<TABLE>
<S>                                 <C>
                                    to carry such amount forward as an offset to OID, if
                                    any, accruing in future accrual periods.
                                    Under the REMIC Regulations (as defined herein), the
                                    Residual Certificates will not be regarded as having
                                    "significant value" for purposes of applying the rules
                                    relating to "excess inclusions". In addition, the
                                    Residual Certificates may constitute "noneconomic"
                                    residual interests for purposes of the REMIC
                                    Regulations. Transfers of the Residual Certificates will
                                    be restricted under the Pooling Agreement to United
                                    States Persons (as defined in the Prospectus) in a
                                    manner designed to prevent a transfer of a noneconomic
                                    residual interest from being disregarded under the REMIC
                                    Regulations. See "Certain Federal Income Tax
                                    Consequences -- Special Tax Considerations Applicable to
                                    the Residual Certificates" herein and "Certain Federal
                                    Income Tax Consequences -- Taxation of Owners of REMIC
                                    Residual Certificates -- Excess Inclusions" and "--
                                    Noneconomic REMIC Residual Certificates" in the
                                    Prospectus.
                                    The Residual Certificateholders may be required to
                                    report an amount of taxable income with respect to the
                                    early years of the REMIC's term that significantly
                                    exceeds distributions on the Residual Certificates
                                    during such years, with corresponding tax deductions or
                                    losses deferred until the later years of the REMIC's
                                    term. Accordingly, on a present value basis, the tax
                                    detriments occurring in the earlier years may
                                    substantially exceed the sum of any tax benefits in the
                                    later years. As a result, the Residual
                                    Certificateholders' after-tax rate of return may be zero
                                    or negative, even if their pre-tax rate of return is
                                    positive.
                                    The Offered Certificates will generally be treated as
                                    "qualifying real property loans" for mutual savings
                                    banks and domestic building and loan associations,
                                    "loans secured by an interest in real property" for
                                    domestic building and loan associations, and "real
                                    estate assets" for real estate investment trusts
                                    ("REITs") in the same proportion that the assets in the
                                    REMIC would be so treated. In addition, interest on the
                                    Offered Certificates will generally be treated as
                                    "interest on obligations secured by mortgages on real
                                    property" for REITs to the extent that such Certificates
                                    are treated as "real estate assets". See "Certain
                                    Federal Income Tax Consequences" in the Prospectus.
                                    For further information regarding the federal income tax
                                    consequences of investing in the Offered Certificates,
                                    see "Certain Federal Income Tax Consequences" herein and
                                    in the Prospectus.
</TABLE>
 
                                      S-44
<PAGE>
                                  RISK FACTORS
 
EFFECT OF PRINCIPAL PREPAYMENTS
 
    The rate of principal payments, amount of each interest payment and yield to
maturity on each Class of the Certificates are directly related to the rate of
payments of principal on the Mortgage Loans in the related Loan Group, which may
be in the form of scheduled amortization, principal prepayments or liquidations.
In general, when the level of prevailing mortgage interest rates declines
significantly below the interest rates on the Mortgage Loans, the rate of
prepayment is likely to increase, although the prepayment rate is influenced by
a number of other factors, including general economic conditions and homeowner
mobility. The rate of payment of principal will also be affected by any
repurchase by the Company of the Mortgage Loans in the related Loan Group. See
"Maturity, Average Life and Prepayment Assumptions" and "Description of
Certificates -- Termination" in the Prospectus and "Description of the
Certificates -- Optional Termination of the Trust" and "Yield and Prepayment
Considerations" herein. In such event, the repurchase price paid by the Company
would be passed through to related Certificateholders on the Distribution Date
following the month of repurchase. All of the Mortgage Loans contain
"due-on-sale" clauses. Consequently, acceleration of maturity as a result of
transfers of Mortgaged Properties will affect the level of prepayments on the
Mortgage Loans.
 
    If any Certificate is purchased at a discount from its original Certificate
Principal Balance, and if a purchaser of such Certificate calculates the yield
to maturity based on an assumed rate of principal payments (including Principal
Prepayments) and liquidations faster than that actually received on the Mortgage
Loans in the related Loan Group, the actual yield to maturity will be lower than
that so calculated. If any Certificate is purchased at a premium from its
original Certificate Principal Balance, and if a purchaser of such Certificate
calculates the yield to maturity based on an assumed rate of principal payments
(including Principal Prepayments) and liquidations slower than that actually
received on the Mortgage Loans in the related Loan Group, the actual yield to
maturity will be lower than that so calculated.
 
    Principal distributions on the Class IA-4, Class IA-5 and Class IA-6
Certificates and the PAC Components of the Class IA-1 and Class IA-2
Certificates (the "Group I PACs") on any Distribution Date are generally payable
based on the Planned Principal Balances set forth in Appendix A. The Planned
Principal Balances for the Group I PACs were determined assuming that the
prepayment rate of the Group I Loans occur each month at a constant level
between approximately 105% and 300% of the Basic Prepayment Assumption (as
defined herein). However, as discussed herein, actual principal distributions
may deviate from the described amounts, because the actual prepayment rate of
such Group I Loans each month may not occur at a constant level between
approximately 105% and 300% of the Basic Prepayment Assumption. If the Class
IA-7 Principal Balance and the Component Balances of the Companion Component of
the Class IA-1 Certificates and the TAC Component of the Class IA-2 Certificates
are reduced to zero before the Class Principal Balances and Component Balances
of the Group I PACs are reduced to zero, the weighted average lives of the Group
I PACs will become significantly more sensitive to changes in the prepayment
rate of the Group I Loans, and principal distributions thereon will be more
likely to deviate from the described amounts.
 
    Principal distributions (other than principal distributions in respect of
the Class IA-7 Accrual Amount) on the TAC Component of the Class IA-2
Certificates (the "Group I TAC") on any Distribution Date are generally payable
based on the Targeted Principal Balances set forth in Appendix B. The Targeted
Principal Balances of such Component were determined assuming that the
prepayment rate of the Group I Loans remains constant at 240% of the Basic
Prepayment Assumption. However, as discussed herein, actual principal
distributions may deviate from the described amounts, because the actual
prepayment rate of the Group I Loans each month may not remain constant at 240%
of the Basic Prepayment Assumption. If the Class IA-7 Principal Balance has been
reduced to zero, the rate of principal distributions and the weighted average
life of the Group I TAC will become significantly more sensitive to changes in
the prepayment rate of the Group I Loans.
 
                                      S-45
<PAGE>
    Principal prepayments on the Group I Loans and other unscheduled payments of
principal may result in principal available for distribution on a Distribution
Date to the Group I PACs and Group I TAC on such Distribution Date in an amount
greater than the amount necessary to reduce the applicable Class Principal and
Component Balances of the Group I PACs and the Component Balance of the Group I
TAC to their scheduled amounts. A percentage of such excess principal after
payment of the Group I PACs will be distributed to the Companion Component of
the Class IA-1 Certificates, and the remainder of such excess will be
distributed to the Group I TAC to the extent of its scheduled amount, then to
the Class IA-7 Certificates, until the Class IA-7 Principal Balance has been
reduced to zero and then to the Group I TAC until the Component Balance thereof
has been reduced to zero. Any excess after all such payments will be distributed
to the Group I PACs in the order by which the Group I PACs received their
scheduled amounts of principal, without regard to their respective Planned
Principal Balances. Accordingly, the rate of payments on the Group I Loans is
expected to have a greater effect on the weighted average life of the Companion
Component of the Class IA-1 Certificates and the Class IA-7 Certificates, and
under certain prepayment scenarios the Group I TAC, than on the weighted average
lives of the Group I PACs. If the rate of Principal Prepayments and other
unscheduled payments of principal causes the principal available for
distribution on the Group I Certificates on any Distribution Date to be less
than the amounts determined on the basis of tables as described herein to be
necessary to reduce the Class Principal and Component Balances of the Group I
PACs then entitled to receive principal to their respective Planned Principal
Balances, the Companion Component of the Class IA-1 Certificates, the Class IA-7
Certificates and the Group I TAC (other than in respect of the Class IA-7
Accrual Amount) will not receive any distributions of principal, and if the
principal available for distribution to the Group I TAC is less than the amount
determined on the basis of tables as described herein to be necessary to reduce
the Component Balance of the Group I TAC to its Targeted Principal Balance, the
Class IA-7 Certificates will not receive any distributions of principal. See
"Yield and Prepayment Considerations" herein.
 
    Principal distributions on the Class IIA-2, Class IIA-6 and Class IIA-7
Certificates and the PAC Component of the Class IIA-1 Certificates (the "Group
II PACs") will be payable in amounts determined on the basis of the Planned
Principal Balances set forth in Appendix A. The Planned Principal Balances for
the Group II PACs were determined assuming that the prepayment rate of the Group
II Loans occur each month at a constant level between approximately 100% and
500% of the Basic Prepayment Assumption (as defined herein). However, as
discussed herein, actual principal distributions may deviate from the described
amounts, because the actual prepayment rate of the Group II Loans each month may
not occur at a constant level between approximately 100% and 500% of the Basic
Prepayment Assumption. If the Class Principal Balance of the Class IIA-3
Certificates and the Component Balance of the TAC Component of the Class IIA-1
Certificates (the "Group II TACs") and the Class Principal Balance of the Class
IIA-5 Certificates are reduced to zero before the Class Principal and Component
Balances of the Group II PACs are reduced to zero, the weighted average lives of
the Group II PACs will become significantly more sensitive to changes in the
prepayment rate of the Group II Loans, and principal distributions thereon will
be more likely to deviate from the described amounts.
 
    Principal distributions (other than principal distributions in respect of
the TAC Component Accrual Amount and Class IIA-5 Accrual Amount) on the Group II
TACs on any Distribution Date are payable based on the Targeted Principal
Balances set forth in Appendix B. The Targeted Principal Balances were
determined assuming that the prepayment rate of the Group II Loans remains
constant at 250% of the Basic Prepayment Assumption. However, as discussed
herein, actual principal distributions may deviate from the described amounts,
because the actual prepayment rate of Group II Loans each month may not remain
constant at 250% of the Basic Prepayment Assumption. If the Class IIA-5
Principal Balance has been reduced to zero, the rate of principal distributions
and the weighted average life of the Group II TACs will become significantly
more sensitive to changes in the prepayment rate of the Group II Loans.
 
    Principal prepayments on the Group II Loans and other unscheduled payments
of principal may result in principal available for distribution to the Group II
PACs and the Group II TACs on a Distribution Date in an amount greater than the
amount necessary to reduce the applicable Class Principal and
 
                                      S-46
<PAGE>
Component Balances of the Group II PACs and the applicable Class Principal and
Component Balances of the Group II TACs to their scheduled amounts. Such excess
will be distributed first to the Class IIA-5 Certificates until the Class IIA-5
Principal Balance has been reduced to zero, then to the Group II TACs (first to
the Class IIA-3 Certificates until the Class IIA-3 Principal Balance has been
reduced to zero and then to the TAC Component of the Class IIA-1 Certificates
until the Component Balance of such TAC Component has been reduced to zero) and
then to the Group II PACs (first to the Class IIA-2 Certificates until the Class
IIA-2 Principal Balance has been reduced to zero then to the Class IIA-6
Certificates until the Class IIA-6 Principal Balance has been reduced to zero,
then to the Class IIA-7 Certificates until the Class IIA-7 Principal Balance has
been reduced to zero and then to the PAC Component of the Class IIA-1
Certificates until the Component Balance of such PAC Component has been reduced
to zero). Accordingly, the rate of payments on the Group II Loans is expected to
have a greater effect on the weighted average life of the Class IIA-5
Certificates, and under certain prepayment scenarios the Group II TACs, than on
the weighted average lives of the Group II PACs. If the rate of Principal
Prepayments and other unscheduled payments of principal causes the principal
available for distribution on the Group II Certificates on any Distribution Date
to be less than the amounts determined on the basis of tables as described
herein to be necessary to reduce the Class Principal or Component Balances of
the Group II PACs then entitled to receive principal to their Planned Principal
Balances and to reduce the Class Principal or Component Balances of the Group II
TACs to their Targeted Principal Balances, the Class IIA-5 Certificates will not
receive any distribution of principal. See "Yield and Prepayment Considerations"
herein.
 
    The yields to maturity on the Class X and Class IP Certificates will be
extremely sensitive to the level of Principal Prepayments on the Mortgage Loans
in the related Loan Group. The interest payable to the Class IX-1 Certificates
is based on the weighted average of the Stripped Interest Rates (as defined
herein) of the Group I Loans having Pass-Through Rates in excess of 7.000% and
having remaining terms to maturity (reflecting Curtailments received on or prior
to the Cut-Off Date) of less than or equal to 165 months as of the Cut-Off Date
(the "Class IX-1 15-Year Premium Rate Mortgage Loans"). The interest payable to
the Class IX-2 Certificates is based on the weighted average of the Stripped
Interest Rates of the Group I Loans having Pass-Through Rates in excess of
7.000% and having remaining terms to maturity (reflecting Curtailments received
on or prior to the Cut-Off Date) of greater than 165 months as of the Cut-Off
Date (the "Class IX-2 15-Year Premium Rate Mortgage Loans"). The interest
payable to the Class IIX Certificates is based on the weighted average of the
Stripped Interest Rates of the Group II Loans in excess of 7.500% (the "30-Year
Premium Rate Mortgage Loans"). The Class IX-1 15-Year Premium Rate Mortgage
Loans, the Class IX-2 15-Year Premium Rate Mortgage Loans, and the 30-Year
Premium Rate Mortgage Loans are collectively the "Premium Rate Mortgage Loans".
Therefore the yield to maturity on any Class of the Class X Certificates will
generally decrease as a result of faster than expected Principal Prepayments on
the related group of Premium Rate Mortgage Loans. Prospective investors should
fully consider the risks associated with an investment in the Class X
Certificates, including the possibility that if the rate of Principal
Prepayments on the related Premium Rate Mortgage Loans is rapid, such investors
may not fully recoup their initial investments. Because the principal payable
with respect to the Class IP Certificates (which are entitled to receive
distributions of principal only) is derived from Group I Loans with Pass-Through
Rates that are lower than 7.000%, the yield to maturity on the Class IP
Certificates will be adversely affected by slower than expected prepayments of
Group I Loans with Pass-Through Rates less than 7.000%. Because the interest
payable on the Class IX Certificates and the principal distributable to the
Class IP Certificates are derived from different groups of Mortgage Loans within
Loan Group I, it is possible that faster than expected Principal Prepayments
with respect to the Class IX Certificates may occur at the same time as slower
than expected Principal Prepayments with respect to the Class IP Certificates.
See "Yield and Prepayment Considerations" herein.
 
    Although the Lockout Certificates are Senior Certificates, the Class IA-3
and Class IIA-4 Certificates will generally not be entitled to receive any
distributions of Principal Prepayments until May 2002. Therefore, the Class IA-3
and Class IIA-4 Certificates will not be entitled to receive the
disproportionate
 
                                      S-47
<PAGE>
allocation of Principal Prepayments in the related Loan Group that the other
Senior Certificates in the same Certificate Group are entitled to receive.
 
    The yield to maturity on each Class of the Senior Subordinate Certificates
of a Certificate Group will be extremely sensitive to realized losses on the
Mortgage Loans in the related Loan Group (other than all Special Hazard Losses
and Fraud Losses and Bankruptcy Losses in excess of the applicable coverage
therefor provided by the Class B Certificates), because a disproportionately
large amount of such losses (rather than a pro rata portion thereof) generally
will be allocable to such Classes of Certificates following the reduction of the
aggregate of the Class Principal Balances of the related Junior Subordinate
Certificates to zero, as described under "Description of the Certificates --
Subordination and Allocation of Losses" herein.
 
CROSS-COLLATERALIZATION
 
    Investors in the Senior Certificates should be aware that the coverage for
Special Hazard Losses covers Mortgage Loans in both Loan Groups. Therefore, in
the event Mortgage Loans in a Loan Group suffer a high level of Special Hazard
Losses, it will reduce the available coverage for the Senior Certificates of
both Certificate Groups and also will cause Senior Certificates of a Certificate
Group to suffer losses in the event Mortgage Loans in the related Loan Group
suffer such losses after the available coverage has been exhausted,
notwithstanding minimal Special Hazard Losses in such Loan Group prior thereto.
 
BOOK-ENTRY SYSTEM
 
    Since transactions in the Class A Certificates that are Offered Certificates
(the "Book-Entry Certificates") generally can be effected only through The
Depository Trust Company ("DTC"), participating organizations, indirect
participants and certain banks, the ability of a Certificateholder to pledge a
Book-Entry Certificate to persons or entities that do not participate in the DTC
system, or otherwise to take actions with respect to such Certificates, may be
limited due to a lack of a physical certificate representing the Book-Entry
Certificates. In addition, the Certificateholders may experience some delay in
their receipt of distributions of interest and principal on the Book-Entry
Certificates, since such distributions will be forwarded by the Trustee (or its
duly appointed paying agent, if any) to DTC, and DTC will credit such
distributions to the accounts of DTC Participants (as defined herein) which will
thereafter credit them to the accounts of Certificateholders either directly or
indirectly through indirect participants. Also, issuance of the Book-Entry
Certificates in book-entry form may reduce the liquidity thereof in any
secondary trading market that may develop therefor because investors may be
unwilling to purchase securities for which they cannot obtain delivery of
physical certificates. See "Description of the Certificates -- Book-Entry
Registration" herein.
 
                                   THE TRUST
 
    The primary assets of the Trust will consist of a pool (the "Mortgage Pool")
of Mortgage Loans. The Trust will also contain (i) certain insurance policies
related to the Mortgage Loans, (ii) any property which secured a Mortgage Loan
and which is acquired by foreclosure or by deed in lieu of foreclosure after the
Cut-Off Date, (iii) amounts held in the Certificate Account, and (iv) certain
other assets. Funds otherwise required to be held in the Certificate Account may
be held in an investment account and invested for the benefit of the Company in
Eligible Investments pursuant to the terms of the Pooling Agreement described
herein. The Mortgage Loans will be assigned to the Trustee, together with all
principal and interest due on the Mortgage Loans after the Cut-Off Date. The
Trustee will, concurrently with such assignment, authenticate and deliver the
Certificates. Each Mortgage Loan will be identified in a schedule appearing as
an exhibit to the Pooling Agreement (the "Mortgage Loan Schedule") which will
specify with respect to each Mortgage Loan, among other things, the applicable
Loan Group, the original principal balance and the outstanding principal balance
as of the close of business on the Cut-Off Date, the term of the Mortgage Note
and the Mortgage Interest Rate.
 
                                      S-48
<PAGE>
                       DESCRIPTION OF THE MORTGAGE POOL*
 
    The Mortgage Pool will consist of Mortgage Loans that will have an aggregate
principal balance outstanding as of April 1, 1997 (the "Cut-Off Date"), after
deducting payments due on or before that date, of approximately $511,030,337.
The Group I Loans and Group II Loans have an aggregate principal balance
outstanding as of the Cut-Off Date, after deducting payments due on or before
that date, of approximately $151,981,114 and $359,049,223, respectively. Certain
of the risks of loss on certain Mortgage Loans will be covered up to specified
limits by Primary Insurance Policies.
 
    The Mortgage Loans are secured by first mortgages or first deeds of trust or
other similar security instruments creating first liens on one- to four-family
residential properties or shares of stock relating to cooperative apartments
(the "Mortgaged Properties"), which may include detached homes, duplexes,
townhouses, individual condominium units, individual units in planned unit
developments and other attached dwelling units which are part of buildings
consisting of more than four units (so long as the property subject to the lien
of the related Mortgage consists of no more than four units other than
cooperative apartments), and having the additional characteristics described
below and in the Prospectus.
 
    Each Mortgage Loan will have a first payment date during the period from
February 1990 through May 1997 inclusive, and will have an original term to
maturity of not more than 15 years in the case of Group I Loans and 30 years in
the case of Group II Loans.
 
LOAN GROUP I
 
    As of the Cut-Off Date, the Mortgage Interest Rate on each Group I Loan will
be not less than 6.375% and not more than 9.000% per annum. As of the Cut-Off
Date, the weighted average of the Mortgage Interest Rates on the Group I Loans
will be approximately 7.730% per annum. As of the Cut-Off Date, the Pass-Through
Rate for each Group I Loan will be not less than 6.085% and not more than 8.710%
per annum. As of the Cut-Off Date, the weighted average of the Pass-Through
Rates for the Group I Loans will be approximately 7.440% per annum.
 
    All of the Group I Loans will have principal and interest payable on the
first day of each month (the "Due Date"). None of the Group I Loans will be
Buydown Loans. The latest original scheduled maturity of any Group I Loan will
be February 2012. Each of the Group I Loans will have original terms to maturity
of not more than 15 years, and as of the Cut-Off Date, the weighted average
remaining term to maturity (adjusted for Curtailments) of the Group I Loans will
be approximately 168.4 months. At origination, based upon an appraisal of the
Mortgaged Property securing each Group I Loan, approximately 93.8% of the Group
I Loans will have had Loan-to-Value Ratios less than or equal to 80%, and
approximately 6.2%
 
- ------------------------
 
    *The description herein of the Mortgage Pool and the Mortgaged Properties is
based upon the Mortgage Loans at the close of business on the Cut-Off Date,
after deducting the scheduled principal payments due on or before such date,
whether or not actually received. All references herein to "principal balance"
refer to the principal balance as of the Cut-Off Date, unless otherwise
specifically stated or required by the context. References herein to percentages
of Mortgage Loans refer in each case to the percentage of the aggregate
principal balance of the related Mortgage Loans, based on the outstanding
principal balances of the Mortgage Loans after giving effect to scheduled
Monthly Payments due on or prior to the Cut-Off Date, whether or not received.
References to weighted averages refer, in each case, to weighted averages by
principal balance as of the Cut-Off Date of the related Mortgage Loans
(determined as described in the preceding sentence). Prior to issuance of the
Certificates, Mortgage Loans may be removed from the Mortgage Pool as a result
of principal prepayments in full ("Payoffs"), delinquencies or otherwise. In
such event, other Mortgage Loans may be included in the Mortgage Pool. The
Company believes that the information set forth herein with respect to the
Mortgage Pool is representative of the characteristics of the Mortgage Pool as
it will actually be constituted at the time the Certificates are issued,
although the range of Mortgage Interest Rates and certain other characteristics
of the Mortgage Loans in the Mortgage Pool may vary. See "-- Additional
Information" herein.
 
                                      S-49
<PAGE>
of the Group I Loans will have had Loan-to-Value Ratios greater than 80% but
less than or equal to 95%. No Group I Loan will have had a Loan-to-Value Ratio
at origination greater than 95%. At origination, the weighted average of the
Loan-to-Value Ratios of the Group I Loans was approximately 69.2%. As of the
Cut-Off Date, the weighted average of the Loan-to-Value Ratios of the Group I
Loans is approximately 66.7%. As of the Cut-Off Date, approximately 6.2% of the
Group I Loans are covered by a Primary Insurance Policy. All of the Group I
Loans with Loan-to-Value Ratios as of the Cut-Off Date in excess of 80% were
covered by a Primary Insurance Policy. At origination, each Group I Loan will
have had a principal balance of not less than $23,150 nor more than $1,000,000,
and the average principal balance of the Group I Loans as of the Cut-Off Date
will be approximately $277,845. Approximately 94.3% of the Group I Loans will
have been secured by owner-occupied Mortgaged Properties which were the primary
residences of the related Mortgagors, based solely on representations of the
Mortgagors obtained at the origination of the related Group I Loans, and
approximately 4.0% of the Group I Loans will have been secured by owner-occupied
Mortgaged Properties which were second or vacation homes of the related
Mortgagors, based solely on such representations. Approximately 1.7% of the
Group I Loans will have been secured by Mortgaged Properties which were investor
properties of the related Mortgagors, based solely on such representations.
Approximately 0.5% of the Group I Loans are secured by interests in cooperative
apartments. The aggregate principal balance of Group I Loans originated under
reduced and no documentation programs (including certain Group I Loans for which
verification of income and deposits was not required), which generally limit the
original Loan-to-Value Ratio of the Group I Loan, will be approximately
$16,175,044, which will be approximately 10.6% of the Loan Group I. As of the
Cut-Off Date, the weighted average of the Loan-to-Value Ratios of such Group I
Loans originated under such reduced and no documentation programs is
approximately 64.1%.
 
    Approximately 23.4% of the Group I Loans are secured by Mortgaged Properties
located in California; 9.3%, in Florida; 8.8%, in Illinois; 6.7%, in Michigan;
6.3%, in Colorado; 5.7%, in Texas; and no other single state contains Mortgaged
Properties securing more than 5.0% of the Group I Loans. No more than 1.0% of
the Group I Loans will be secured by Mortgaged Properties located in any one
California zip code area, and no more than 0.9% of the Group I Loans will be
secured by Mortgaged Properties located in any other single zip code area.
Approximately 71.7% of the Group I Loans will have been originated for the
purpose of refinancing existing mortgage debt, including cash-out refinancings.
Approximately 28.3% of the Group I Loans will have been originated for the
purpose of purchasing the Mortgaged Property.
 
LOAN GROUP II
 
    As of the Cut-Off Date, the Mortgage Interest Rate on each Group II Loan
will be not less than 7.000% and not more than 9.875% per annum. As of the
Cut-Off Date, the weighted average of the Mortgage Interest Rates on the Group
II Loans will be approximately 8.145% per annum. As of the Cut-Off Date, the
Pass-Through Rate for each Group II Loan will be not less than 6.710% and not
more than 9.585% per annum. As of the Cut-Off Date, the weighted average of the
Pass-Through Rates for the Group II Loans will be approximately 7.856% per
annum.
 
    All of the Group II Loans will have principal and interest payable on the
first day of each month (the "Due Date"). Approximately 0.1% of the Group II
Loans will be Buydown Loans. The latest original scheduled maturity of any Group
II Loan will be April 2027. Each of the Group II Loans will have original terms
to maturity of not more than 30 years, and as of the Cut-Off Date, the weighted
average remaining term to maturity (adjusted for Curtailments) of the Group II
Loans will be approximately 356.6 months. At origination, based upon an
appraisal of the Mortgaged Property securing each Group II Loan, approximately
81.9% of the Group II Loans will have had Loan-to-Value Ratios less than or
equal to 80%, and approximately 18.1% of the Group II Loans will have had
Loan-to-Value Ratios greater than 80% but less than or equal to 95%. No Group II
Loan will have had a Loan-to-Value Ratio at origination greater than 95%. At
origination, the weighted average of the Loan-to-Value Ratios of the Group II
Loans was
 
                                      S-50
<PAGE>
approximately 75.7%. As of the Cut-Off Date, the weighted average of the
Loan-to-Value Ratios of the Group II Loans is approximately 75.6%. As of the
Cut-Off Date, approximately 18.2% of the Group II Loans are covered by a Primary
Insurance Policy. All of the Group II Loans with Loan-to-Value Ratios as of the
Cut-Off Date in excess of 80% were covered by a Primary Insurance Policy. At
origination, each Group II Loan will have had a principal balance of not less
than $33,600 nor more than $1,200,000 and the average principal balance of the
Group II Loans as of the Cut-Off Date will be approximately $277,044.
Approximately 96.0% of the Group II Loans will have been secured by
owner-occupied Mortgaged Properties which were the primary residences of the
related Mortgagors, based solely on representations of the Mortgagors obtained
at the origination of the related Group II Loans, and approximately 3.2% of the
Group II Loans will have been secured by owner-occupied Mortgaged Properties
which were second or vacation homes of the related Mortgagors, based solely on
such representations. Approximately 0.8% of the Group II Loans will have been
secured by Mortgaged Properties which were investor properties of the related
Mortgagors, based solely on such representations. Approximately 0.1% of the
Group II Loans are secured by interests in cooperative apartments. The aggregate
principal balance of Group II Loans in the Loan Group II originated under
reduced and no documentation programs (including certain Group II Loans for
which verification of income and deposits was not required), which generally
limit the original Loan-to-Value Ratio of the Group II Loan, will be
approximately $55,425,148, which will be approximately 15.4% of the Loan Group
II. As of the Cut-Off Date, the weighted average of the Loan-to-Value Ratios of
such Group II Loans originated under such reduced and no documentation programs
is approximately 71.4%.
 
    Approximately 31.1% of the Group II Loans are secured by Mortgaged
Properties located in California; 8.3%, in Michigan; 6.3%, in Illinois; and no
other single state contains Mortgaged Properties securing more than 5% of the
Group II Loans. No more than 0.6% of the Group II Loans will be secured by
Mortgaged Properties located in any one California zip code area, and no more
than 0.6% of the Group II Loans will be secured by Mortgaged Properties located
in any other single zip code area. Approximately 45.9% of the Group II Loans
will have been originated for the purpose of refinancing existing mortgage debt,
including cash-out refinancings. Approximately 54.1% of the Group II Loans will
have been originated for the purpose of purchasing the Mortgaged Property.
 
ADDITIONAL INFORMATION
 
    A Current Report on Form 8-K relating to the Offered Certificates containing
a detailed description of the Mortgage Loans will be available to purchasers of
Offered Certificates at or before initial issuance of the Offered Certificates
and will be filed with the Securities and Exchange Commission within 15 days
after such initial issuance. The Current Report on Form 8-K will specify as of
the Cut-Off Date the aggregate principal balance of the Mortgage Loans and will
set forth in detail the following information regarding such Mortgage Loans for
each Loan Group: the number of Mortgage Loans, the range of Mortgage Interest
Rates, the range of Mortgage Loan original principal balances, the years in
which initial Monthly Payments on the Mortgage Loans are due, the weighted
average remaining term to maturity of the Mortgage Loans, the range of Loan
to-Value Ratios of the Mortgage Loans as of the Cut-Off Date, the types of
Mortgaged Properties, the stated owner occupancy status of the Mortgaged
Properties at the time the Mortgage Loans were originated, the geographic
distribution by state of the Mortgage Properties, the scheduled maturity years
of the Mortgage Loans (adjusted for Curtailments), the original terms of the
Mortgage Loans, the Mortgagors' purpose of financing, the number of Mortgage
Loans originated under a reduced documentation program, if any, and the number
of Buydown Loans, if any, in each case, for each Loan Group and for the Mortgage
Pool.
 
                        DESCRIPTION OF THE CERTIFICATES
 
GENERAL
 
    The Certificates will be issued pursuant to a Pooling and Servicing
Agreement (the "Pooling Agreement") to be dated as of the Cut-Off Date between
the Company, as Depositor and Master Servicer,
 
                                      S-51
<PAGE>
and First Bank National Association, as trustee (the "Trustee"), a form of which
is filed as an exhibit to the Registration Statement of which this Prospectus
Supplement is a part. Reference is made to the Prospectus for important
additional information regarding the terms and conditions of the Pooling
Agreement and the Certificates. It is a condition to the issuance of the Offered
Certificates that the Class A Certificates and Class R Certificates each be
rated "AAA" by Standard & Poor's, a division of The McGraw-Hill Companies, Inc.
("S&P") and by Duff & Phelps Credit Rating Co. ("DCR"), that the Class X and
Class IP Certificates each be rated "AAAr" by S&P and "AAA" by DCR and that the
Class IB-1 and Class IIB-1 Certificates be rated not less than "AA" by DCR, the
Class IB-2 and Class IIB-2 Certificates be rated not less than "A" by DCR and
the Class IB-3 and Class IIB-3 Certificates be rated not less than "BBB" by DCR.
See "Certificate Ratings" herein. At the time of their issuance, the Offered
Certificates, other than the Class IB-2, Class IB-3, Class IIB-2 and Class IIB-3
Certificates, will qualify as "mortgage related securities" within the meaning
of the Secondary Mortgage Market Enhancement Act of 1984.
 
    The Master Servicer will be obligated to make Advances with respect to
delinquent payments on Mortgage Loans as described herein under "-- Advances".
 
    The Certificates will evidence all the beneficial ownership in a trust (the
"Trust") established by the Company into which the mortgage loans (the "Mortgage
Loans") will be deposited. The Mortgage Pass-Through Certificates, Series 1997-3
(the "Certificates"), will consist of the following thirty-one classes: (i)
Class IA-1, Class IA-2, Class IA-3, Class IA-4, Class IA-5, Class IA-6 and Class
IA-7 (the "Group IA Certificates"), (ii) Class IIA-1, Class IIA-2, Class IIA-3,
Class IIA-4, Class IIA-5, Class IIA-6 and Class IIA-7 (the "Group IIA
Certificates" and, together with the Group IA Certificates, the "Class A
Certificates"), (iii) Class IP, (iv) Class IX-1 and Class IX-2 (the "Class IX
Certificates") and Class IIX (together with the Class IX Certificates, the
"Class X Certificates"), (v) Class IB-1, Class IB-2 and Class IB-3 (the "Group I
Senior Subordinate Certificates"), (vi) Class IB-4, Class IB-5 and Class IB-6
(the "Group I Junior Subordinate Certificates" and, together with the Group I
Senior Subordinate Certificates, the "Group IB Certificates"), (vii) Class
IIB-1, Class IIB-2 and Class IIB-3 (the "Group II Senior Subordinate
Certificates"), (viii) Class IIB-4, Class IIB-5 and Class IIB-6 (the "Group II
Junior Subordinate Certificates" and, together with the Group II Senior
Subordinate Certificates, the "Group IIB Certificates") and (ix) Class R (the
"Residual Certificates" and, together with the Class A, Class X and Class IP
Certificates, the "Senior Certificates"). The Group IA, Class IP, Class IX and
Group IB Certificates are sometimes referred to as the "Group I Certificates"
and the Group IIA, Class IIX and Group IIB Certificates are sometimes referred
to as the "Group II Certificates". The Group I Certificates and Group II
Certificates are each a "Certificate Group". The Class IA-3 and Class IIA-4
Certificates are sometimes referred to as the "Lockout Certificates". The Group
I Senior Subordinate Certificates and Group II Senior Subordinate Certificates
are collectively referred to as the "Senior Subordinate Certificates". The Group
I Junior Subordinate Certificates and Group II Junior Subordinate Certificates
are collectively referred to as the "Junior Subordinate Certificates". The Group
IB and Group IIB Certificates are collectively referred to as the "Subordinate
Certificates" or "Class B Certificates". Only the Senior Certificates (other
than the Class IIA-1 Certificates) and the Senior Subordinate Certificates
(collectively, the "Offered Certificates") are offered hereby. The Class IIA-1
Certificates and the Junior Subordinate Certificates are not offered hereby. The
"Class Principal Balance" for any Class of Certificates (other than the Class
IA-1, Class IA-2 and Class IIA-1 Certificates) will equal the aggregate amount
of principal to which such Class is entitled, after giving effect to prior (i)
distributions of principal to such Class, (ii) allocations of losses required to
be borne by such Class and (iii) in the case of Class IA-7 and the Class IIA-5
Certificates, increased by all interest accrued and added to the Class Principal
Balance thereof.
 
    The Class IA-1 , Class IA-2 and Class IIA-1 Certificates will be comprised
of multiple components (each, a "Component"), each of which will have a
specified principal balance (a "Component Balance") or notional amount (a
"Component Notional Amount"), which functions in a manner comparable to that of
a Class Principal Balance or Class Notional Amount, on which interest will
accrue at a designated Remittance Rate. Holders of a Class of Certificates
comprised of Components will be entitled to receive
 
                                      S-52
<PAGE>
distributions on any Distribution Date to the extent of the amount distributed
with respect to the related Components on such Distribution Date. Holders of a
Class of Certificates comprised of Components may not transfer such Components
separately. The Class IA-1 Certificates will be comprised of a PAC Component and
a Companion Component with initial Component Balances of $11,330,672 and
$25,219,689, respectively. The Class IA-2 Certificates will be comprised of a
PAC Component and a TAC Component with initial Component Balances of $7,984,500
and $11,800,000, respectively. The Class IIA-1 Certificates (which are not
offered hereby) will be comprised of a PAC Component, a TAC Component, an IO
Component and a PO Component. The Class Principal Balances of the Class IA-1,
Class IA-2 and Class IIA-1 Certificates will equal the sum of the Component
Balances thereof. The Component Balance for each Component will equal the
aggregate amount of principal to which such Component is entitled, after giving
effect to prior (i) distributions of principal to such Component, (ii)
allocations of losses required to be borne by such Component and (iii) in the
case of the TAC Component of the IIA-1 Certificates, increased by all interest
accrued and added to the Component Balance thereof.
 
    The "Certificate Principal Balance" for any Certificate will be the portion
of the corresponding Class Principal Balance represented by such Certificate.
The aggregate initial Certificate Principal Balance will be approximately equal
to the aggregate principal balance of the Mortgage Loans as of the Cut-Off Date.
The Group I Certificates that are Senior Certificates will comprise
approximately 97.00%, the Group I Senior Subordinate Certificates will comprise
approximately 2.25%, and the Group I Junior Subordinate Certificates will
comprise approximately 0.75% of the initial aggregate Certificate Principal
Balance of the Group I Certificates. The Group II Certificates that are Senior
Certificates will comprise approximately 95.25%, the Group II Senior Subordinate
Certificates will comprise approximately 3.75%, and the Group II Junior
Subordinate Certificates will comprise approximately 1.00% of the initial
aggregate Certificate Principal Balance of the Group II Certificates. The
initial aggregate Certificate Principal Balance of the Group IA and Group IIA
Certificates comprise approximately 96.91% and 94.90%, respectively, of the
initial aggregate principal balance of the Group I Certificates and the Group II
Certificates, respectively, as of the Cut-Off Date. The Offered Certificates,
other than the Class X and Class R Certificates, are offered in minimum
denominations equivalent to not less than $25,000 initial Certificate Principal
Balance each and multiples of $1 in excess thereof, except that one Class IP
Certificate may be issued in a different amount. The Class X Certificates are
offered in minimum denominations equivalent to not less than $100,000 initial
Class Notional Amount each and multiples of $1 in excess thereof, except that
one Class IX-1, one Class IX-2 and one Class IIX Certificate may be issued in a
different amount. The Class R Certificates, which will have an initial Class
Principal Balance of $50, will be offered in registered, certificated form in a
single denomination of a 99.99% Percentage Interest. The remaining 0.01%
Percentage Interest of the Class R Certificates will be retained by the Company
as set forth herein under "Certain Federal Income Tax Consequences".
 
    Each Class of Book-Entry Certificates will initially be represented by a
global Certificate registered in the name of the nominee of DTC. DTC has advised
the Company that DTC's nominee will be Cede & Co. ("Cede"). Accordingly, Cede is
expected to be the holder of record of the Book-Entry Certificates. No
Book-Entry Certificateholder will be entitled to receive a certificate
representing such person's interest in such Certificate. Unless and until
Definitive Certificates (as defined below) are issued under the limited
circumstances described herein, all references herein to actions by Book-Entry
Certificateholders shall refer to actions taken by DTC upon instructions from
DTC Participants (as defined below), and all references herein to distributions,
notices, reports, and statements to Book-Entry Certificateholders shall refer to
distributions, notices, reports, and statements to Cede, as the registered
holder of such Certificates, for distribution to Book-Entry Certificateholders
in accordance with DTC procedures. See "-- Book-Entry Registration" and "--
Definitive Certificates" herein.
 
                                      S-53
<PAGE>
BOOK-ENTRY REGISTRATION
 
    Certificateholders may hold their Book-Entry Certificates through DTC, if
they are DTC Participants (as defined below), or indirectly through
organizations which are DTC Participants. Transfers between DTC Participants
will occur in the ordinary way in accordance with DTC rules. Cede, as nominee of
DTC, will hold the global Certificates for the Book-Entry Certificates.
 
    DTC has advised the Company that it is a limited-purpose trust company
organized under the New York Banking Law, a "banking organization" within the
meaning of the New York Banking Law, a member of the Federal Reserve System, a
"clearing corporation" within the meaning of the New York Uniform Commercial
Code and a "clearing agency" registered pursuant to the provisions of Section
17A of the Securities Exchange Act of 1934, as amended. DTC holds securities
that its participants ("DTC Participants") deposit with DTC. DTC also
facilitates the settlement among DTC Participants of securities transactions,
such as transfers and pledges, in deposited securities through electronic
computerized book-entry changes in DTC Participants' accounts, thereby
eliminating the need for physical movement of securities certificates. DTC
Participants include the Underwriter, securities brokers and dealers, banks,
trust companies, clearing corporations and certain other organizations. Indirect
access to the DTC system also is available to other entities, such as banks,
brokers, dealers, and trust companies that clear through or maintain a custodial
relationship with a DTC Participant, either directly or indirectly ("Indirect
DTC Participants").
 
    Certificateholders that are not DTC Participants or Indirect DTC
Participants but desire to purchase, sell, or otherwise transfer ownership of or
other interests in Book-Entry Certificates may do so only through DTC
Participants and Indirect DTC Participants. In addition, unless Definitive
Certificates are issued, Certificateholders will receive all distributions of
principal and interest on the Book-Entry Certificates through DTC Participants.
Under a book-entry format, Certificateholders will receive payments after the
related Distribution Date because, while payments are required to be forwarded
to Cede, as nominee for DTC, on each such date, DTC will forward such payments
to DTC Participants which thereafter will be required to forward them to
Indirect DTC Participants or Certificateholders. It is anticipated that the sole
"Certificateholder" (as such term is used in the Pooling Agreement) for each
Class of Book-Entry Certificates will be Cede, as nominee of DTC, and that
Book-Entry Certificateholders will not be recognized by the Trustee as
Certificateholders under the Pooling Agreement. Book-Entry Certificateholders
will be permitted to exercise the rights of Certificateholders under the Pooling
Agreement only indirectly through DTC Participants, who in turn will exercise
their rights through DTC.
 
    Under the rules, regulations and procedures creating and affecting DTC and
its operations (the "Rules"), DTC is required to make book-entry transfers among
DTC Participants on whose behalf it acts with respect to the Book-Entry
Certificates and is required to receive and transmit payments of principal and
interest, if any, on such Book-Entry Certificates. DTC Participants and Indirect
DTC Participants with whom Book-Entry Certificateholders have accounts with
respect to the Book-Entry Certificates similarly are required to make book-entry
transfers and receive and transmit such payments on behalf of their respective
Book-Entry Certificateholders. Accordingly, although owners of Book-Entry
Certificates will not possess Definitive Certificates, the Rules provide a
mechanism by which owners of the Book-Entry Certificates through their DTC
Participants will receive payments and will be able to transfer their interest.
 
    Because DTC can only act on behalf of DTC Participants, who in turn act on
behalf of Indirect DTC Participants and certain banks, the ability of a
Book-Entry Certificateholder to pledge Book-Entry Certificates to persons or
entities that do not participate in the DTC system, or otherwise take actions in
respect of such Book-Entry Certificates, may be limited due to the lack of a
physical certificate for such Book-Entry Certificates.
 
    DTC has advised the Company that it will take any action permitted to be
taken by a Book-Entry Certificateholder under the Pooling Agreement only at the
direction of one or more DTC Participants to whose account with DTC the
Certificates are credited. Additionally, DTC has advised the Company that it
 
                                      S-54
<PAGE>
will take such actions with respect to a Book-Entry Certificate only at the
direction of and on behalf of the DTC Participant whose holdings include that
Certificate. DTC may take conflicting actions with respect to other Book-Entry
Certificates to the extent that such actions are taken on behalf of DTC
Participants whose holdings include such Book-Entry Certificates.
 
    Although DTC has agreed to the foregoing procedures in order to facilitate
transfers of Book-Entry Certificates among DTC Participants, it is under no
obligation to perform or continue to perform such procedures and such procedures
may be discontinued at any time.
 
DEFINITIVE CERTIFICATES
 
    The Book-Entry Certificates will be issued in fully registered, certificated
form to Certificateholders or their nominees ("Definitive Certificates"), rather
than to DTC or its nominee, only if (i) the Company advises the Trustee in
writing that DTC is no longer willing or able to discharge properly its
responsibilities as Depository with respect to the Book-Entry Certificates and
the Trustee or the Company is unable to locate a qualified successor, (ii) the
Company, at its option, elects to terminate the book-entry system through DTC or
(iii) after the occurrence of an Event of Default, Certificateholders of
Book-Entry Certificates evidencing not less than 66% of the aggregate
outstanding Certificate Principal Balance advise the Trustee and DTC through DTC
Participants in writing that the continuation of a book-entry system through DTC
(or a successor thereto) is no longer in the best interests of the
Certificateholders.
 
    Upon notice of the occurrence of any of the events described in the
immediately preceding paragraph, DTC is required to notify all DTC Participants
of the availability of Definitive Certificates. Upon surrender by DTC of the
global Certificates and receipt from DTC of instructions for re-registration,
the Trustee will issue the Book-Entry Certificates in the form of Definitive
Certificates, and thereafter the Trustee will recognize the holders of such
Definitive Certificates as Certificateholders under the Pooling Agreement.
 
    Distributions of principal and interest on the Definitive Certificates, as
well as the other Classes of Certificates, will be made by the Trustee (or its
duly appointed paying agent, if any) directly to holders of such Certificates in
accordance with the procedures set forth herein and in the Pooling Agreement.
Distributions of principal and interest on each Distribution Date will be made
to holders in whose names such Certificates were registered at the close of
business on the related Record Date. Distributions will be made by wire transfer
in immediately available funds for the account of each such holder or, if a
holder has not provided wire instructions, by check mailed to the address of
such holder as it appears on the register maintained by the Certificate
Registrar. The final payment on any Certificate (whether Class X, Class IP,
Class R Certificates, Class B, Definitive Certificates or the global
Certificates registered in the name of Cede) will be made only upon presentation
and surrender of such Certificate at the offices of the Trustee or its agent or
such office or agency as is specified in the notice of final distribution to
holders of Certificates being retired. The Trustee will provide such notice to
registered Certificateholders not later than the fifteenth day of the month in
which all remaining outstanding Certificates will be retired.
 
    Definitive Certificates, as well as the other Classes of Certificates, will
be transferable and exchangeable at the offices of the Trustee in New York City.
A reasonable service charge may be imposed for any registration of transfer or
exchange, and the Trustee or such agent may require payment of a sum sufficient
to cover any tax or other governmental charge imposed in connection therewith.
 
PRIORITY OF DISTRIBUTIONS
 
    Commencing in May 1997, on the 25th day of each month, or if such 25th day
is not a business day, on the immediately succeeding business day (each, a
"Distribution Date"), distributions will be made in the order and priority as
follows:
 
                                      S-55
<PAGE>
        (a) with respect to the Group I and Class R Certificates, prior to the
    Group I Credit Support Depletion Date (as defined herein), to the extent of
    the Available Distribution Amount for Loan Group I remaining following prior
    distributions, if any, on such Distribution Date:
 
                (i) first, to the Class IP Certificates, the Class IP Fraction
           (as defined herein) of all principal received on or in respect of
           each Class IP Mortgage Loan (as defined herein);
 
                (ii) second, (a) to the Group IA, Class IX and Class R
           Certificates, accrued and unpaid interest at their respective
           Remittance Rates on their respective Class Principal Balances (or the
           Class IX-1 and Class IX-2 Notional Amounts, in the case of the Class
           IX Certificates, and on their respective Component Balances, in the
           case of the PAC Component and Companion Component of the Class IA-1
           Certificates and the PAC Component and TAC Component of the Class
           IA-2 Certificates), reduced in the case of the Class IA-7
           Certificates on or before the Class IA-7 Accretion Termination Date
           (as defined herein) by the Class IA-7 Accrual Amount (as defined
           herein), and (b) on or before the Class IA-7 Accretion Termination
           Date, to the TAC Component of the Class IA-2 Certificates, as
           principal, to the extent of the Component Balance of the TAC
           Component of the Class IA-2 Certificates, the Class IA-7 Accrual
           Amount;
 
               (iii) third, to the Group IA and the Class R Certificates, as
           principal, the Group IA Principal Distribution Amount (as defined
           herein) in the order described in "-- Distributions of Principal --
           GROUP IA PRINCIPAL DISTRIBUTION AMOUNT" herein;
 
                (iv) fourth, to the Class IP Certificates, to the extent of
           amounts otherwise available to pay the Group I Subordinate Principal
           Distribution Amount (as defined herein) (without regard to clauses
           (I)(B) and (II) of such definition) on such Distribution Date, the
           sum of (a) principal in an amount equal to the Class IP Fraction of
           certain principal losses on the Class IP Mortgage Loans, as described
           in "-- Distributions of Principal -- CLASS IP DISTRIBUTION AMOUNT"
           herein and (b) the sum of amounts, if any, by which the amount
           described in clause (a) above on each prior Distribution Date
           exceeded the amount actually distributed in respect thereof on such
           prior Distribution Dates and not subsequently distributed; PROVIDED
           that any amounts distributed in respect of losses pursuant to this
           paragraph shall not cause a further reduction in the Class IP
           Principal Balance;
 
                (v) fifth, to the Class IB-1 Certificates, accrued and unpaid
           interest at the Class IB-1 Remittance Rate on the Class IB-1
           Principal Balance;
 
                (vi) sixth, to the Class IB-1 Certificates, their pro rata share
           of the Group I Subordinate Principal Distribution Amount;
 
               (vii) seventh, to the Class IB-2 Certificates, accrued and unpaid
           interest at the Class IB-2 Remittance Rate on the Class IB-2
           Principal Balance;
 
              (viii) eighth, to the Class IB-2 Certificates, their pro rata
           share of the Group I Subordinate Principal Distribution Amount;
 
                (ix) ninth, to the Class IB-3 Certificates, accrued and unpaid
           interest at the Class IB-3 Remittance Rate on the Class IB-3
           Principal Balance;
 
                (x) tenth, to the Class IB-3 Certificates, their pro rata share
           of the Group I Subordinate Principal Distribution Amount;
 
                (xi) eleventh, to the Group I Junior Subordinate Certificates,
           interest and principal in the same manner as for the Group I Senior
           Subordinate Certificates, first to the Class IB-4 Certificates, then
           to the Class IB-5 Certificates and then to the Class IB-6
           Certificates;
 
                                      S-56
<PAGE>
               (xii) twelfth, to each Class of Group I Subordinate Certificates
           in order of seniority, the remaining portion, if any, of the
           Available Distribution Amount for Loan Group I, up to the amount of
           unreimbursed realized losses previously allocated to such Class, if
           any, provided distribution of any amount pursuant to this paragraph
           shall not cause a further reduction in the Class Principal Balances
           of the Group I Subordinated Certificates; and
 
              (xiii) thirteenth, to the Class R Certificates, the remaining
           portion, if any, of the Available Distribution Amount for Loan Group
           I for such Distribution Date; and
 
        (b) with respect to the Group II and Class R Certificates, prior to the
    Group II Credit Support Depletion Date, to the extent of the Available
    Distribution Amount for Loan Group II remaining following prior
    distributions, if any, on such Distribution Date:
 
                (i) first, to the PO Component of the Class IIA-1 Certificates,
           the PO Component Fraction (as defined herein) of all principal
           received on or in respect of each PO Component Mortgage Loan (as
           defined herein);
 
                (ii) second, (a) to the Group IIA and Class IIX Certificates,
           accrued and unpaid interest at their respective Remittance Rates on
           their respective Class Principal Balances (or the Class IIX Notional
           Amount in the case of the Class IIX Certificates and the respective
           Component Balances or Component Notional Amounts in the case of the
           PAC Component, TAC Component and IO Component of the Class IIA-1
           Certificates), reduced in the case of the TAC Component of the Class
           IIA-1 Certificates on or before the TAC Component Accretion
           Termination Date (as defined herein) by the TAC Component Accrual
           Amount (as defined herein), and further reduced in the case of the
           Class IIA-5 Certificates on or before the Class IIA-5 Accretion
           Termination Date (as defined herein) by the Class IIA-5 Accrual
           Amount (as defined herein), and (b) on or before the TAC Component
           Accretion Termination Date, to the Class IIA-3 Certificates, as
           principal, to the extent of its Class Principal Balance, the sum of
           the TAC Component Accrual Amount and the Class IIA-5 Accrual Amount
           and (c) after the TAC Component Accretion Termination Date until and
           including the Class IIA-5 Accretion Termination Date, to the TAC
           Component of the Class IIA-1 Certificates, as principal, to the
           extent of the TAC Component Balance of the Class IIA-1 Certificates,
           the Class IIA-5 Accrual Amount;
 
               (iii) third, to the Group IIA Certificates (other than the PO
           Component of the Class IIA-1 Certificates), as principal, the Group
           IIA Principal Distribution Amount in the order described in "--
           Distributions of Principal -- GROUP IIA PRINCIPAL DISTRIBUTION
           AMOUNT" herein;
 
                (iv) fourth, to the PO Component of the Class IIA-1
           Certificates, to the extent of amounts otherwise available to pay the
           Group II Subordinate Principal Distribution Amount (as defined
           herein) (without regard to clauses (I)(B) and (II) of such
           definition) on such Distribution Date, the sum of (a) principal in an
           amount equal to the PO Component Fraction of certain principal losses
           on the PO Component Mortgage Loans, as described in "Distributions of
           Principal -- PO COMPONENT PRINCIPAL DISTRIBUTION AMOUNT" herein and
           (b) the sum of amounts, if any, by which the amount described in
           clause (a) above on each prior Distribution Date exceeded the amount
           actually distributed in respect thereof on such prior Distribution
           Dates and not subsequently distributed; PROVIDED that any amounts
           distributed in respect of losses pursuant to this paragraph shall not
           cause a further reduction in the PO Component Balance;
 
                (v) fifth, to the Class IIB-1 Certificates, accrued and unpaid
           interest at the Class IIB-1 Remittance Rate on the Class IIB-1
           Principal Balance;
 
                (vi) sixth, to the Class IIB-1 Certificates, their pro rata
           share of the Group II Subordinate Principal Distribution Amount;
 
                                      S-57
<PAGE>
               (vii) seventh, to the Class IIB-2 Certificates, accrued and
           unpaid interest at the Class IIB-2 Remittance Rate on the Class IIB-2
           Principal Balance;
 
              (viii) eighth, to the Class IIB-2 Certificates, their pro rata
           share of the Group II Subordinate Principal Distribution Amount;
 
                (ix) ninth, to the Class IIB-3 Certificates, accrued and unpaid
           interest at the Class IIB-3 Remittance Rate on the Class IIB-3
           Principal Balance;
 
                (x) tenth, to the Class IIB-3 Certificates, their pro rata share
           of the Group II Subordinate Principal Distribution Amount;
 
                (xi) eleventh, to the Group II Junior Subordinate Certificates,
           interest and principal in the same manner as for the Group II Senior
           Subordinate Certificates, first to the Class IIB-4 Certificates, then
           to the Class IIB-5 Certificates and then to the Class IIB-6
           Certificates;
 
               (xii) twelfth, to each Class of Group II Subordinate Certificates
           in order of seniority, the remaining portion, if any, of the
           Available Distribution Amount for Loan Group II, up to the amount of
           unreimbursed realized losses previously allocated to such Class, if
           any, provided distribution of any amount pursuant to this paragraph
           shall not cause a further reduction in the Class Principal Balances
           of the Group II Subordinated Certificates; and
 
              (xiii) thirteenth, to the Class R Certificates, the remaining
           portion, if any, of the Available Distribution Amount for Loan Group
           II for such Distribution Date.
 
    The Class IA-7 Accretion Termination Date is the earlier to occur of (i) the
Distribution Date on which the Component Balance of the TAC Component of the
Class IA-2 Certificates has been reduced to zero and (ii) the Group I Credit
Support Depletion Date. On each Distribution Date on or before the Class IA-7
Accretion Termination Date, an amount (the "Class IA-7 Accrual Amount") equal to
the lesser of (i) the accrued interest that would otherwise be distributable in
respect of the Class IA-7 Certificates on such Distribution Date and (ii) the
Component Balance of the TAC Component of the Class IA-2 Certificates will be
added to the Class IA-7 Principal Balance, and such amount will be distributed,
as principal, to the TAC Component of the Class IA-2 Certificates. The amount so
added to the Class IA-7 Principal Balance will thereafter accrue interest at the
Class IA-7 Remittance Rate.
 
    The TAC Component Accretion Termination Date is the earlier to occur of (i)
the Distribution Date on which the Class IIA-3 Principal Balance has been
reduced to zero and (ii) the Group II Credit Support Depletion Date. On each
Distribution Date on or before the TAC Component Accretion Termination Date, an
amount (the "TAC Component Accrual Amount") equal to the lesser of (i) the
accrued interest that would otherwise be distributable in respect of the TAC
Component of the Class IIA-1 Certificates on such Distribution Date and (ii) the
Class IIA-3 Principal Balance will be added to the Component Balance of the TAC
Component of the Class IIA-1 Certificates, and such amount will be distributed,
as principal, to the Class IIA-3 Certificates. The amount so added to the
Component Balance of the TAC Component of the Class IIA-1 Certificates will
thereafter accrue interest at the Remittance Rate for the TAC Component of the
Class IIA-1 Certificates.
 
    The Class IIA-5 Accretion Termination Date is the earlier to occur of (i)
the Distribution Date on which the Component Balance of the TAC Component of the
Class IIA-1 Certificates has been reduced to zero and (ii) the Group II Credit
Support Depletion Date. On each Distribution Date on or before the Class IIA-5
Accretion Termination Date, an amount (the "Class IIA-5 Accrual Amount") equal
to the lesser of (i) the accrued interest that would otherwise be distributable
in respect of the Class IIA-5 Certificates on such Distribution Date and (ii)
the Component Balance of the TAC Component of the Class IIA-1 Certificates will
be added to the Class IIA-5 Principal Balance, and such amount will be
distributed, as principal, sequentially (a) to the Class IIA-3 Certificates,
until the Class IIA-3 Principal Balance is reduced to zero and (b) to the TAC
Component of the Class IIA-1 Certificates until the
 
                                      S-58
<PAGE>
Component Balance thereof is reduced to zero. The amounts so added to the Class
IIA-5 Principal Balance will thereafter accrue interest at the Class IIA-5
Remittance Rate.
 
    With respect to the Class B Certificates of each Certificate Group,
notwithstanding the foregoing, on any Distribution Date on which the
Subordination Level (as defined herein) for any Class of Class B Certificates in
a Certificate Group is less than such percentage as of the Cut-Off Date, the
portion of the Subordinate Principal Distribution Amount of the related
Certificate Group otherwise allocable to the Class or Classes of the Class B
Certificates in the related Certificate Group junior to such Class will be
allocated to the most senior Class of Class B Certificates in the related
Certificate Group for which the Subordination Level is less than such percentage
as of the Cut-Off Date and to the Class or Classes of Class B Certificates in
the related Certificate Group senior thereto, pro rata according to the Class
Principal Balances of such Classes.
 
    The "Subordination Level" on any specified date with respect to any Class of
Class B Certificates is the percentage obtained by dividing the sum of the Class
Principal Balances of all Classes of Certificates in the related Certificate
Group which are subordinate in right of payment to such Class by the sum of the
Class Principal Balances of all of the Certificates in the related Certificate
Group as of such date prior to giving effect to distributions or allocations of
realized losses on the Mortgage Loans in the related Loan Group on such date.
 
    On each Distribution Date on or after the Group I Credit Support Depletion
Date, distributions will be made with respect to the Group I and Class R
Certificates, subject, in each case, to the extent of the Available Distribution
Amount of Loan Group I remaining following prior distributions, if any, on such
Distribution Date:
 
        (i) first, to the Class IP Certificates, the Class IP Fraction of all
    principal received on or in respect of each Class IP Mortgage Loan;
 
        (ii) second, to the Group IA, Class IX and Class R Certificates, accrued
    and unpaid interest at their respective Remittance Rates on their respective
    Class Principal Balances (or the Class IX-1 and Class IX-2 Notional Amounts,
    in the case of the Class IX Certificates, and on their respective Component
    Balances, in the case of the PAC Component and Companion Component of the
    Class IA-1 Certificates and the PAC Component and TAC Component of the Class
    IA-2 Certificates);
 
       (iii) third, to the Group IA Certificates and the Class R Certificates,
    the Group IA Principal Distribution Amount, pro rata according to their
    respective Class Principal Balances; and
 
        (iv) fourth, to the Class R Certificates, the remaining portion, if any,
    of the Available Distribution Amount for Loan Group I for such Distribution
    Date, as described in the Pooling Agreement.
 
    The "Group I Credit Support Depletion Date" is the first Distribution Date
on which the aggregate of the Class Principal Balances of the Group IB
Certificates has been or will be reduced to zero.
 
    On each Distribution Date on or after the Group II Credit Support Depletion
Date, distributions will be made with respect to the Group II and Class R
Certificates, subject, in each case, to the extent of the Available Distribution
Amount of Loan Group II remaining following prior distributions, if any, on such
Distribution Date:
 
        (i) first, to the PO Component of the Class IIA-1 Certificates, the PO
    Component Fraction of all principal received on or in respect of each PO
    Component Mortgage Loan;
 
        (ii) second, to the Group II Certificates (other than the PO Component
    of the Class IIA-1 Certificates), accrued and unpaid interest at their
    respective Remittance Rates on their respective Class Principal Balances (or
    Class IIX Notional Amount in the case of the Class IIX Certificates and on
    their respective Component Balances and Component Notional Amounts, in the
    case of the PAC Component, TAC Component and IO Component of the Class IIA-1
    Certificates);
 
                                      S-59
<PAGE>
       (iii) third, to the Group IIA Certificates, the Group IIA Principal
    Distribution Amount, pro rata according to their respective Class Principal
    Balances (or the Component Balances, other than the PO Component Balance, in
    the case of the Class IIA-1 Certificates); and
 
        (iv) fourth, to the Class R Certificates, the remaining portion, if any,
    of the Available Distribution Amount for Loan Group II for such Distribution
    Date, as described in the Pooling Agreement.
 
    The "Group II Credit Support Depletion Date" is the first Distribution Date
on which the aggregate of the Class Principal Balances of the Group IIB
Certificates has been or will be reduced to zero.
 
    Except for the limited circumstances described herein under "--
Cross-Collateralization", distributions of interest and principal to the Group I
Certificates and the Group II Certificates will be based solely on payments
received with respect to Group I Loans and Group II Loans, respectively.
 
DISTRIBUTIONS OF INTEREST
 
    With respect to each Class of Certificates (except the Class IP Certificates
and the PO Component of the Class IIA-1 Certificates, which are not entitled to
interest), interest will be passed through monthly on each Distribution Date,
commencing in May 1997, except that (1) interest accrued on the Class IA-7
Certificates on or before the Class IA-7 Accretion Termination Date will be
added to the Class IA-7 Principal Balance, (2) interest accrued on the TAC
Component of the Class IIA-1 Certificates on or before the TAC Component
Accretion Termination Date will be added to the TAC Component Balance of the
Class IIA-1 Certificates and (3) interest accrued on the Class IIA-5
Certificates on or before the Class IIA-5 Accretion Termination Date will be
added to the Class IIA-5 Principal Balance. With respect to each Distribution
Date, an amount of interest will accrue on each Class of Certificates (other
than the Class IP Certificates), or, with respect to the Class IA-1
Certificates, the PAC Component and the Companion Component, or, with respect to
the Class IA-2 Certificates, the PAC Component and TAC Component, or, with
respect to the Class IIA-1 Certificates, the PAC Component, TAC Component and IO
Component, generally equal to 1/12th of the applicable Remittance Rate for such
Class or Component multiplied by the related Class Principal Balance, Component
Balance, Class Notional Amount or Component Notional Amount, as applicable.
Interest will not accrue on the Class IP Certificates nor on the PO Component of
the Class IIA-1 Certificates. Interest to be distributed on the Certificates on
any Distribution Date will consist of accrued and unpaid interest as of previous
Distribution Dates and interest accrued during the preceding calendar month. All
distributions of interest for each Class of Certificates will generally be made
only to the extent of the Available Distribution Amount for the related Loan
Group as described herein under "-- Priority of Distributions"
 
    The Remittance Rates for the Class A, Class X, Class R and Senior
Subordinate Certificates are fixed as set forth on the cover page hereof. The
Remittance Rates for the PAC Component and the Companion Component of the Class
IA-1 Certificates will each be 7.000%. The Remittance Rates for the PAC
Component and the TAC Component of the Class IA-2 Certificates will each be
7.000%. The Remittance Rates for the PAC Component and the TAC Component of the
Class IIA-1 Certificates will each be 7.500%.
 
    The Class X Certificates and the IO Component will accrue interest on the
applicable Class Notional Amount or Component Notional Amount, respectively.
 
    The Class IX-1 Certificates will accrue interest on the Class IX-1 Notional
Amount. The "Class IX-1 Notional Amount" with respect to any Distribution Date
will equal the product of (x) the aggregate scheduled principal balance, as of
the second preceding Due Date after giving effect to payments scheduled to be
received as of such Due Date, whether or not received, or with respect to the
initial Distribution Date, as of the Cut-Off Date, of the Group I Loans having
Pass-Through Rates in excess of 7.000% per annum and having remaining terms to
maturity (reflecting Curtailments received on or prior to the Cut-Off Date) of
less than or equal to 165 months as of the Cut-Off Date (the "Class IX-1 15-Year
 
                                      S-60
<PAGE>
Premium Rate Mortgage Loans") and (y) a fraction, the numerator of which is the
weighted average of the Stripped Interest Rates (as defined herein) for the
Class IX-1 15-Year Premium Rate Mortgage Loans as of such Due Date and the
denominator of which is 7.000%. The Class IX-1 Notional Amount as of the Cut-Off
Date will be approximately $3,563,719.
 
    The Class IX-2 Certificates will accrue interest on the Class IX-2 Notional
Amount. The "Class IX-2 Notional Amount" with respect to any Distribution Date
will equal the product of (x) the aggregate scheduled principal balance, as of
the second preceding Due Date after giving effect to payments scheduled to be
received as of such Due Date, whether or not received, or with respect to the
initial Distribution Date, as of the Cut-Off Date, of the Group I Loans having
Pass-Through Rates in excess of 7.000% per annum and having remaining terms to
maturity (reflecting Curtailments received on or prior to the Cut-Off Date) of
greater than 165 months as of the Cut-Off Date (the "Class IX-2 15-Year Premium
Rate Mortgage Loans") and (y) a fraction, the numerator of which is the weighted
average of the Stripped Interest Rates for the Class IX-2 15-Year Premium Rate
Mortgage Loans as of such Due Date and the denominator of which is 7.000%. The
Class IX-2 Notional Amount as of the Cut-Off Date will be approximately
$6,117,050.
 
    The Class IIX Certificates will accrue interest on the Class IIX Fraction of
the Group II Notional Amount (the "Class IIX Notional Amount"). The "Class IIX
Fraction" with respect to any Distribution Date will equal 30.2074506121%. The
"Group II Notional Amount" with respect to any Distribution Date will equal the
product of (x) the aggregate scheduled principal balance, as of the second
preceding Due Date after giving effect to payments scheduled to be received as
of such Due Date, whether or not received, or with respect to the initial
Distribution Date, as of the Cut-Off Date, of the Group II Loans having
Pass-Through Rates in excess of 7.500% per annum (the "30-Year Premium Rate
Mortgage Loans") and (y) a fraction, the numerator of which is the weighted
average of the Stripped Interest Rates for the 30-Year Premium Rate Mortgage
Loans as of such Due Date and the denominator of which is 7.500%. The Class IIX
Notional Amount as of the Cut-Off Date will be approximately $5,525,230.
 
    The "IO Component Notional Amount" with respect to any Distribution Date
will equal the IO Fraction of the Group II Notional Amount. The "IO Fraction"
with respect to any Distribution Date will equal 69.7925493879%. The IO
Component Notional Amount as of the Cut-Off Date will be approximately
$12,765,721.
 
    The "Stripped Interest Rate" means (i) for each Group I Loan, the excess, if
any, of the Pass-Through Rate for such Mortgage Loan over 7.000%, and (ii) for
each Group II Loan, the excess, if any, of the Pass-Through Rate for such
Mortgage Loan over 7.500%. The "Pass-Through Rate" for each Mortgage Loan is
equal to the Mortgage Interest Rate thereon less the sum of the related Master
Servicing Fee and Servicing Fee (each, as defined herein).
 
    COMPENSATING INTEREST.  Subject to the limitations described in this
Prospectus Supplement under "Yield and Prepayment Considerations", on each
Distribution Date the Master Servicer is obligated to pass through an amount
equal to the lesser of (a) any shortfall for the related month in interest
collections resulting from the timing of Payoffs made from the 15th day of the
calendar month preceding such Distribution Date to the last day of such month,
and (b) the monthly Master Servicing Fee, any reinvestment income realized by
the Master Servicer relating to Payoffs made from the 15th day of the calendar
month preceding such Distribution Date to the 14th day of the month of such
Distribution Date and interest payments on Payoffs received during the period of
the first day through the 14th day of the month of such Distribution Date. The
amount so passed through will hereinafter be referred to as "Compensating
Interest". Compensating Interest will be allocated to each Class of Certificates
pro rata according to the amount of interest accrued thereon, and any remaining
shortfall in interest collections resulting from the timing of Payoffs will be
applied pro rata according to the amount of interest to which each Class of
Certificates would otherwise be entitled in reduction thereof. See "Yield and
Prepayment Considerations" herein and "Yield Considerations -- Effective
Interest Rate" in the Prospectus.
 
                                      S-61
<PAGE>
DISTRIBUTIONS OF PRINCIPAL
 
    GENERAL.  On each Distribution Date, Certificateholders will be entitled to
receive principal distributions from the Available Distribution Amount to the
extent and priority described herein. See "-- Priority of Distributions" herein.
Except for limited circumstances described under "-- Cross-Collateralization"
herein, the Group I Certificates (other than the Class IX Certificates which
will not receive principal) will receive principal collected from Group I Loans
and the Group II Certificates (other than the Class IIX Certificates and the IO
Component of the Class IIA-1 Certificates which will not receive principal) will
receive principal collected from Group II Loans.
 
    GROUP I CERTIFICATE PRINCIPAL DISTRIBUTIONS
 
    CLASS IP PRINCIPAL DISTRIBUTION AMOUNT.  On each Distribution Date, the
Class IP Certificates will receive a portion of the Available Distribution
Amount for Loan Group I attributable to principal received on or in respect of
any Group I Loan with a Pass-Through Rate of less than 7.000% (a "Class IP
Mortgage Loan"), equal to the amount of such principal so attributable
multiplied by a fraction, the numerator of which is 7.000% minus the
Pass-Through Rate on such Class IP Mortgage Loan and the denominator of which is
7.000% (the "Class IP Fraction"). In addition, on each Distribution Date for so
long as any Class of Group IB Certificates remains outstanding, the Class IP
Certificates will also be allocated principal, to the extent of amounts
available to pay the Group I Subordinate Principal Distribution Amount (without
regard to clauses (I)(B) and (II) of such definition) on such Distribution Date,
in an amount generally equal to (i) the Class IP Fraction of any loss on a Class
IP Mortgage Loan other than a Special Hazard Loss in excess of the Special
Hazard Coverage, a Fraud Loss in excess of the Group I Fraud Coverage or a
Bankruptcy Loss in excess of the Group I Bankruptcy Coverage (each, as defined
herein) and (ii) the sum of amounts, if any, by which the foregoing amount on
each prior Distribution Date exceeded the amount actually distributed in respect
thereof on such prior Distribution Dates and not subsequently distributed;
PROVIDED, that such payments in respect of losses shall not cause a further
reduction of the outstanding Class IP Principal Balance. The aggregate of the
amounts payable to the Class IP Certificates described in this paragraph are
referred to herein as the "Class IP Principal Distribution Amount".
 
    GROUP IA PRINCIPAL DISTRIBUTION AMOUNT.  On each Distribution Date prior to
the Group I Credit Support Depletion Date, an amount, up to the amount of the
Group IA Principal Distribution Amount (as defined below) for such Distribution
Date, will be distributed as principal to the following Classes of Group IA
Certificates and Class R Certificates in the following order of priority:
 
        (i) first, to the Class IA-3 Certificates, an amount, up to the amount
    of the Class IA-3 Principal Distribution Amount (as defined below) for such
    Distribution Date, until the Class IA-3 Principal Balance has been reduced
    to zero;
 
        (ii) second, the portion of the Group IA Principal Distribution Amount
    remaining after the distribution described above, concurrently:
 
           (A) 58.6620300352% to the PAC Component of the Class IA-1
       Certificates, to the extent necessary to reduce the Component Balance of
       such PAC Component to its planned principal balance for such Distribution
       Date, as set forth in Appendix A herein (its "Planned Principal
       Balance"); and
 
            (B) 41.3379699648% to the PAC Component of the Class IA-2
       Certificates, to the extent necessary to reduce the Component Balance of
       such PAC Component to its Planned Principal Balance for such Distribution
       Date;
 
                                      S-62
<PAGE>
       (iii) third, to the Class IA-4 Certificates, the portion of the Group IA
    Principal Distribution Amount remaining after the distributions described
    above, to the extent necessary to reduce the Class IA-4 Principal Balance to
    its Planned Principal Balance for such Distribution Date;
 
        (iv) fourth, to the Class IA-5 Certificates, the portion of the Group IA
    Principal Distribution Amount remaining after the distributions described
    above, to the extent necessary to reduce the Class IA-5 Principal Balance to
    its Planned Principal Balance for such Distribution Date;
 
        (v) fifth, to the Class IA-6 Certificates, the portion of the Group IA
    Principal Distribution Amount remaining after the distributions described
    above, to the extent necessary to reduce the Class IA-6 Principal Balance to
    its Planned Principal Balance for such Distribution Date;
 
        (vi) sixth, the portion of the Group IA Principal Distribution Amount
    remaining after the distributions described above, concurrently:
 
           (A) 65.2751643521% to the Companion Component of the Class IA-1
       Certificates until the Component Balance of such Companion Component has
       been reduced to zero; and
 
            (B) 34.7248356479% sequentially as follows:
 
                (1) first, to the TAC Component of the Class IA-2 Certificates
           to the extent necessary to reduce the Component Balance of such TAC
           Component to its targeted principal balance for such Distribution
           Date, as set forth in Appendix B herein (its "Targeted Principal
           Balance");
 
                (2) second, to the Class IA-7 Certificates until the Class IA-7
           Principal Balance has been reduced to zero; and
 
                (3) third, to the TAC Component of the Class IA-2 Certificates
           until the Component Balance of such TAC Component has been reduced to
           zero;
 
       (vii) seventh, to the Class R Certificates, the portion of the Group IA
    Principal Distribution Amount remaining after the distributions described
    above, until the Class R Principal Balance has been reduced to zero;
 
      (viii) eighth, the portion of the Group IA Principal Distribution Amount
    remaining after the distributions described above, concurrently:
 
           (A) 58.6620300352% to the PAC Component of the Class IA-1
       Certificates, until the Component Balance of such PAC Component has been
       reduced to zero; and
 
            (B) 41.3379699648% to the PAC Component of the Class IA-2
       Certificates, until the Component Balance of such PAC Component has been
       reduced to zero;
 
        (ix) ninth, to the Class IA-4 Certificates, the portion of the Group IA
    Principal Distribution Amount remaining after the distributions described
    above, until the Class IA-4 Principal Balance has been reduced to zero;
 
        (x) tenth, to the Class IA-5 Certificates, the portion of the Group IA
    Principal Distribution Amount remaining after the distributions described
    above, until the Class IA-5 Principal Balance has been reduced to zero;
 
        (xi) eleventh, to the Class IA-6 Certificates, the portion of the Group
    IA Principal Distribution Amount remaining after the distributions described
    above, until the Class IA-6 Principal Balance has been reduced to zero; and
 
       (xii) twelfth, to the Class IA-3 Certificates, the portion of the Group
    IA Principal Distribution Amount remaining after the distributions described
    above, until the Class IA-3 Principal Balance has been reduced to zero.
 
                                      S-63
<PAGE>
    The "Group IA Principal Distribution Amount" for any Distribution Date will
equal the sum of (i) the Group IA Percentage (as defined below) of the Principal
Payment Amount (as defined below) for Loan Group I (exclusive of the portion
thereof attributable to the Class IP Principal Distribution Amount), (ii) the
Group IA Prepayment Percentage (as defined below) of the Principal Prepayment
Amount (as defined below) for Loan Group I (exclusive of the portion thereof
attributable to the Class IP Principal Distribution Amount), and (iii) the Group
IA Liquidation Amount (as defined below).
 
    The "Group IA Percentage" for any Distribution Date will equal the sum of
the Class Principal Balances of the Group IA Certificates and the Class R
Certificates divided by the aggregate Class Principal Balance of the Group I
Certificates and the Class R Certificates (less the Class IP Principal Balance),
in each case immediately prior to the Distribution Date.
 
    The "Group IA Liquidation Amount" is the aggregate of, for each Group I Loan
which became a Liquidated Mortgage Loan during the calendar month preceding the
month of the Distribution Date, the lesser of (i) the Group IA Percentage of the
principal balance of such Mortgage Loan (exclusive of the Class IP Fraction
thereof, with respect to any Class IP Mortgage Loan) and (ii) the Group IA
Prepayment Percentage of the Liquidation Principal with respect to such Mortgage
Loan.
 
    "Liquidation Principal" is the principal portion of Liquidation Proceeds
received with respect to each Mortgage Loan which became a Liquidated Mortgage
Loan (as defined herein) (but not in excess of the principal balance thereof)
during the calendar month preceding the month of the Distribution Date,
exclusive of the portion thereof attributable to the applicable Class IP
Principal Distribution Amount or PO Component Principal Distribution Amount. A
"Liquidated Mortgage Loan" is a Mortgage Loan as to which the Master Servicer or
a servicer has determined that all amounts which it expects to recover from or
on account of such Mortgage Loan, whether from Insurance Proceeds, Liquidation
Proceeds or otherwise have been recovered.
 
    The "Group I Subordinate Percentage" for any Distribution Date will equal
the excess of 100% over the Group IA Percentage for such date. The Group IA
Percentage and the Group I Subordinate Percentage as of the Cut-Off Date will be
approximately 97.00% and 3.00%, respectively.
 
    The "Class IA-3 Principal Distribution Amount" for any Distribution Date
will equal the sum of (i) the Class IA-3 Percentage (as defined below) of the
Principal Payment Amount for Loan Group I (exclusive of the portion thereof
attributable to the Class IP Principal Distribution Amount), (ii) the Class IA-3
Prepayment Percentage (as defined herein) of the Principal Prepayment Amount for
Loan Group I (exclusive of the portion thereof attributable to the Class IP
Principal Distribution Amount) and (iii) the Class IA-3 Liquidation Amount (as
defined below).
 
    The "Class IA-3 Percentage" for any Distribution Date will equal the Class
IA-3 Principal Balance divided by the aggregate Class Principal Balance of the
Group I Certificates and the Class R Certificates (less the Class IP Principal
Balance), in each case immediately prior to the Distribution Date.
 
    The "Class IA-3 Liquidation Amount" is the aggregate of, for each Group I
Loan which became a Liquidated Mortgage Loan during the calendar month preceding
the month of the Distribution Date, the lesser of (i) the Class IA-3 Percentage
of the principal balance of such Mortgage Loan (exclusive of the Class IP
Fraction thereof, if applicable) and (ii) the Class IA-3 Percentage on any
Distribution Date occurring prior to the fifth anniversary of the first
Distribution Date and the Class IA-3 Prepayment Percentage (as defined herein)
on any Distribution Date thereafter, in each case, of the Liquidation Principal
with respect to such Mortgage Loan.
 
    GROUP I SUBORDINATE PRINCIPAL DISTRIBUTION AMOUNT.  On each Distribution
Date, an amount, up to the Group I Subordinate Principal Distribution Amount (as
defined below) for such Distribution Date, will be distributed as principal to
the Group IB Certificates. On each Distribution Date, except Distribution Dates
on which the Subordination Level for any Class of Group IB Certificates is less
than such Subordination Level as of the Cut-Off Date, each Class of Group IB
Certificates will be entitled to receive its pro rata (by
 
                                      S-64
<PAGE>
Class Principal Balance) share of the Group I Subordinate Principal Distribution
Amount, to the extent of the Available Distribution Amount for Loan Group I
remaining after distributions of interest and principal to the Group IA, Class
IX, Class IP and Class R Certificates, distributions of interest and principal
to all Classes of Group IB Certificates senior to such Class and distributions
of interest to such Class. See
"-- Priority of Distributions" herein. The relative seniority, from highest to
lowest, of the Group IB Certificates shall be as follows: Class IB-1, Class
IB-2, Class IB-3, Class IB-4, Class IB-5 and Class IB-6.
 
    The "Group I Subordinate Principal Distribution Amount" for any Distribution
Date will be equal to the sum of (I) the excess of (A) the sum of (i) the Group
I Subordinate Percentage of the Principal Payment Amount for Loan Group I
(exclusive of the portion thereof attributable to the Class IP Principal
Distribution Amount), (ii) the Group I Subordinate Prepayment Percentage of the
Principal Prepayment Amount for Loan Group I (exclusive of the portion thereof
attributable to the Class IP Principal Distribution Amount) and (iii) the Group
I Subordinate Liquidation Amount over (B) the amounts required to be distributed
to the Class IP Certificates pursuant to clause (iv) of paragraph (a) under "--
Priority of Distributions" herein on such Distribution Date and (II) any
payments received by Loan Group I with respect to any transfer of principal
owing to it from Loan Group II.
 
    The "Group I Subordinate Liquidation Amount" will equal the excess, if any,
of the aggregate Liquidation Principal for all Group I Loans which became
Liquidated Mortgage Loans during the calendar month preceding the month of the
Distribution Date, over the Group IA Liquidation Amount for such Distribution
Date.
 
    The "Group I Subordinate Prepayment Percentage" for any Distribution Date
will equal the excess of 100% over the Group IA Prepayment Percentage; PROVIDED,
HOWEVER, that if the Class Principal Balance of the Group IA and Class R
Certificates has been reduced to zero, then the Group I Subordinate Prepayment
Percentage will equal 100%.
 
    The rights of the holders of the Group IB Certificates to receive
distributions of interest and principal are subordinated to the rights of the
holders of the Group IA, Class IX, Class IP and Class R Certificates to receive
scheduled distributions of interest and principal. See "-- Subordination and
Allocation of Losses" herein.
 
    GROUP II CERTIFICATE PRINCIPAL DISTRIBUTIONS
 
    PO COMPONENT PRINCIPAL DISTRIBUTION AMOUNT.  On each Distribution Date, the
PO Component of the Class IIA-1 Certificates will receive a portion of the
Available Distribution Amount for Loan Group II attributable to principal
received on or in respect of any Group II Loan with a Pass-Through Rate of less
than 7.500% (a "PO Component Mortgage Loan"), equal to the amount of such
principal so attributable multiplied by a fraction, the numerator of which is
7.500% minus the Pass-Through Rate on such PO Component Mortgage Loan and the
denominator of which is 7.500% (the "PO Component Fraction"). In addition, on
each Distribution Date for so long as any Class of Group IIB Certificates
remains outstanding, the PO Component will also be allocated principal, to the
extent of amounts available to pay the Group II Subordinate Principal
Distribution Amount (without regard to clauses (I)(B) and (II) of such
definition) on such Distribution Date, in an amount generally equal to (i) the
PO Component Fraction of any loss on a PO Component Mortgage Loan other than a
Special Hazard Loss in excess of the Special Hazard Coverage, a Fraud Loss in
excess of the Group II Fraud Coverage or a Bankruptcy Loss in excess of the
Group II Bankruptcy Coverage (each, as defined herein) and (ii) the sum of
amounts, if any, by which the foregoing amount on each prior Distribution Date
exceeded the amount actually distributed in respect thereof on such prior
Distribution Dates and not subsequently distributed; PROVIDED, that such
payments in respect of losses shall not cause a further reduction of the
outstanding Component Balance of the PO Component of the Class IIA-1
Certificates. The aggregate of the amounts payable to the PO Component of the
Class IIA-1 Certificates described in this paragraph are referred to herein as
the "PO Component Principal Distribution Amount".
 
                                      S-65
<PAGE>
    GROUP IIA PRINCIPAL DISTRIBUTION AMOUNT.  On each Distribution Date prior to
the Group II Credit Support Depletion Date, an amount, up to the amount of the
Group IIA Principal Distribution Amount (as defined below) for such Distribution
Date, will be distributed as principal to the following Classes of Group IIA
Certificates in the following order of priority:
 
        (i) first, to the Class IIA-4 Certificates, an amount, up to the amount
    of the Class IIA-4 Principal Distribution Amount (as defined below) for such
    Distribution Date, until the Class IIA-4 Principal Balance has been reduced
    to zero;
 
        (ii) second, to the Class IIA-2 Certificates, the portion of the Group
    IIA Principal Distribution Amount remaining after the distribution described
    above, to the extent necessary to reduce the Class IIA-2 Principal Balance
    to its Planned Principal Balance for such Distribution Date;
 
       (iii) third, to the Class IIA-6 Certificates, the portion of the Group
    IIA Principal Distribution Amount remaining after the distributions
    described above, to the extent necessary to reduce the Class IIA-6 Principal
    Balance to its Planned Principal Balance for such Distribution Date;
 
        (iv) fourth, to the Class IIA-7 Certificates, the portion of the Group
    IIA Principal Distribution Amount remaining after the distributions
    described above, to the extent necessary to reduce the Class IIA-7 Principal
    Balance to its Planned Principal Balance for such Distribution Date;
 
        (v) fifth, to the PAC Component of the Class IIA-1 Certificates, the
    portion of the Group IIA Principal Distribution Amount remaining after the
    distributions described above, to the extent necessary to reduce the
    Component Balance of such PAC Component to its Planned Principal Balance for
    such Distribution Date;
 
        (vi) sixth, to the Class IIA-3 Certificates, the portion of the Group
    IIA Principal Distribution Amount remaining after the distributions
    described above, to the extent necessary to reduce the Class IIA-3 Principal
    Balance to its Targeted Principal Balance for such Distribution Date;
 
       (vii) seventh, to the TAC Component of the Class IIA-1 Certificates, the
    portion of the Group IIA Principal Distribution Amount remaining after the
    distributions described above, to the extent necessary to reduce the
    Component Balance of such TAC Component to its Targeted Principal Balance
    for such Distribution Date;
 
      (viii) eighth, to the Class IIA-5 Certificates, the portion of the Group
    IIA Principal Distribution Amount remaining after the distributions
    described above, until the Class IIA-5 Principal Balance has been reduced to
    zero;
 
        (ix) ninth, to the Class IIA-3 Certificates, the portion of the Group
    IIA Principal Distribution Amount remaining after the distributions
    described above, until the Class IIA-3 Principal Balance has been reduced to
    zero;
 
        (x) tenth, to the TAC Component of the Class IIA-1 Certificates, the
    portion of the Group IIA Principal Distribution Amount remaining after the
    distributions described above, until the Component Balance of such TAC
    Component has been reduced to zero;
 
        (xi) eleventh, to the Class IIA-2 Certificates, the portion of the Group
    IIA Principal Distribution Amount remaining after the distributions
    described above, until the Class IIA-2 Principal Balance has been reduced to
    zero;
 
       (xii) twelfth, to the Class IIA-6 Certificates, the portion of the Group
    IIA Principal Distribution Amount remaining after the distributions
    described above, until the Class IIA-6 Principal Balance has been reduced to
    zero;
 
                                      S-66
<PAGE>
      (xiii) thirteenth, to the Class IIA-7 Certificates, the portion of the
    Group IIA Principal Distribution Amount remaining after the distributions
    described above, until the Class IIA-7 Principal Balance has been reduced to
    zero;
 
       (xiv) fourteenth, to the PAC Component of the Class IIA-1 Certificates,
    the portion of the Group IIA Principal Distribution Amount remaining after
    the distributions described above, until the Component Balance of such PAC
    Component has been reduced to zero;
 
       (xv) fifteenth, to the Class IIA-4 Certificates, the portion of the Group
    IIA Principal Distribution Amount remaining after the distributions
    described above, until the Class IIA-4 Principal Balance has been reduced to
    zero;
 
    The "Group IIA Principal Distribution Amount" for any Distribution Date will
equal the sum of (i) the Group IIA Percentage (as defined below) of the
Principal Payment Amount for Loan Group II (exclusive of the portion thereof
attributable to the PO Component Principal Distribution Amount), (ii) the Group
IIA Prepayment Percentage (as defined below) of the Principal Prepayment Amount
for Loan Group II (exclusive of the portion thereof attributable to the PO
Component Principal Distribution Amount), and (iii) the Group IIA Liquidation
Amount (as defined below).
 
    The "Group IIA Percentage" for any Distribution Date will equal the sum of
the Class Principal Balances of the Group IIA Certificates (less the Component
Balance of the PO Component) divided by the aggregate Class Principal Balance of
the Group II Certificates (less the Component Balance of the PO Component), in
each case immediately prior to the Distribution Date.
 
    The "Group IIA Liquidation Amount" is the aggregate of, for each Group II
Loan which became a Liquidated Mortgage Loan during the calendar month preceding
the month of the Distribution Date, the lesser of (i) the Group IIA Percentage
of the principal balance of such Mortgage Loan (exclusive of the PO Component
Fraction thereof, with respect to any PO Component Mortgage Loan) and (ii) the
Group IIA Prepayment Percentage of the Liquidation Principal with respect to
such Mortgage Loan.
 
    The "Group II Subordinate Percentage" for any Distribution Date will equal
the excess of 100% over the Group IIA Percentage for such date. The Group IIA
Percentage and the Group II Subordinate Percentage as of the Cut-Off Date will
be approximately 95.23% and 4.77%, respectively.
 
    The "Class IIA-4 Principal Distribution Amount" for any Distribution Date
will equal the sum of (i) the Class IIA-4 Percentage (as defined below) of the
Principal Payment Amount for Loan Group II (exclusive of the portion thereof
attributable to the PO Component Principal Distribution Amount), (ii) the Class
IIA-4 Prepayment Percentage (as defined herein) of the Principal Prepayment
Amount for Loan Group II (exclusive of the portion thereof attributable to the
PO Component Principal Distribution Amount) and (iii) the Class IIA-4
Liquidation Amount (as defined below).
 
    The "Class IIA-4 Percentage" for any Distribution Date will equal the Class
IIA-4 Principal Balance divided by the aggregate Class Principal Balance of the
Group II Certificates (less the Component Balance of the PO Component), in each
case immediately prior to the Distribution Date.
 
    The "Class IIA-4 Liquidation Amount" is the aggregate of, for each Group II
Loan which became a Liquidated Mortgage Loan during the calendar month preceding
the month of the Distribution Date, the lesser of (i) the Class IIA-4 Percentage
of the principal balance of such Mortgage Loan (exclusive of the PO Component
Fraction thereof, if applicable) and (ii) the Class IIA-4 Percentage on any
Distribution Date occurring prior to the fifth anniversary of the first
Distribution Date, and the Class IIA-4 Prepayment Percentage (as defined herein)
on any Distribution Date thereafter, in each case, of the Liquidation Principal
with respect to such Mortgage Loan.
 
                                      S-67
<PAGE>
    GROUP II SUBORDINATE PRINCIPAL DISTRIBUTION AMOUNT.  On each Distribution
Date, an amount, up to the Group II Subordinate Principal Distribution Amount
(as defined below) for such Distribution Date, will be distributed as principal
to the Group IIB Certificates. On each Distribution Date, except Distribution
Dates on which the Subordination Level for any Class of Group IIB Certificates
is less than such Subordination Level as of the Cut-Off Date, each Class of
Group IIB Certificates will be entitled to receive its pro rata (by Class
Principal Balance) share of the Group II Subordinate Principal Distribution
Amount, to the extent of the Available Distribution Amount for Loan Group II
remaining after distributions of interest and principal to the Group IIA and
Class IIX Certificates, distributions of interest and principal to all Classes
of Group IIB Certificates senior to such Class and distributions of interest to
such Class. See "-- Priority of Distributions" herein. The relative seniority,
from highest to lowest, of the Group IIB Certificates shall be as follows: Class
IIB-1, Class IIB-2, Class IIB-3, Class IIB-4, Class IIB-5 and Class IIB-6.
 
    The "Group II Subordinate Principal Distribution Amount" for any
Distribution Date will be equal to the sum of (I) the excess of (A) the sum of
(i) the Group II Subordinate Percentage of the Principal Payment Amount for Loan
Group II (exclusive of the portion thereof attributable to the PO Component
Principal Distribution Amount), (ii) the Group II Subordinate Prepayment
Percentage of the Principal Prepayment Amount for Loan Group II (exclusive of
the portion thereof attributable to the PO Component Principal Distribution
Amount) and (iii) the Group II Subordinate Liquidation Amount over (B) the
amounts required to be distributed to the PO Component of the Class IIA-1
Certificates pursuant to clause (iv) of paragraph (b) under "-- Priority of
Distributions" herein on such Distribution Date and (II) any payments received
by Loan Group II with respect to any transfer of principal owing to it from Loan
Group I.
 
    The "Group II Subordinate Liquidation Amount" will equal the excess, if any,
of the aggregate Liquidation Principal for all Group II Loans which became
Liquidated Mortgage Loans during the calendar month preceding the month of the
Distribution Date, over the Group IIA Liquidation Amount for such Distribution
Date.
 
    The "Group II Subordinate Prepayment Percentage" for any Distribution Date
will equal the excess of 100% over the Group IIA Prepayment Percentage;
PROVIDED, HOWEVER, that if the Class Principal Balance of the Group IIA
Certificates (other than the Component Balance of the PO Component of the Class
IIA-1 Certificates) has been reduced to zero, then the Group II Subordinate
Prepayment Percentage will equal 100%.
 
    The rights of the holders of the Group IIB Certificates to receive
distributions of interest and principal are subordinated to the rights of the
holders of the Group IIA Certificates and Class IIX Certificates to receive
scheduled distributions of interest and principal. See "-- Subordination and
Allocation of Losses" herein.
 
    For any Distribution Date and for any Loan Group, the "Principal Payment
Amount" is the sum, with respect to the Mortgage Loans in such Loan Group, of
(i) scheduled principal payments on the Mortgage Loans due on the related Due
Date, (ii) the principal portion of repurchase proceeds received with respect to
any Mortgage Loan which was repurchased as permitted or required by the Pooling
Agreement during the calendar month preceding the month of the Distribution Date
and (iii) any other unscheduled payments of principal which were received from
the Mortgage Loans during the preceding calendar month, other than Payoffs,
Curtailments or Liquidation Principal. For any Distribution Date and for any
Loan Group, the "Principal Prepayment Amount" is the sum, with respect to the
Mortgage Loans in such Loan Group, of (i) all Curtailments from the Mortgage
Loans which were received during the preceding calendar month and (ii) all
Payoffs from the Mortgage Loans received from the 15th day of the month
immediately prior to the month of such Distribution Date through the 14th day of
the month of such Distribution Date (except for Payoffs received from the
Cut-Off Date through April 14, 1997, which will be passed through to holders of
Certificates on the May 1997 Distribution Date). Except as described herein
under "-- Cross-Collateralization", principal distributions to the Group I
Certificates will be based on the
 
                                      S-68
<PAGE>
Principal Payment Amount, Principal Prepayment Amount and Liquidation Principal
for the Group I Loans and principal distributions to the Group II Certificates
will be based on the Principal Payment Amount, Principal Prepayment Amount and
Liquidation Principal for the Group II Loans.
 
    PRINCIPAL PREPAYMENT
 
    The "Group IA Prepayment Percentage" and "Group IIA Prepayment Percentage"
for any Distribution Date occurring prior to the month of the fifth anniversary
of the first Distribution Date will equal 100%. The "Group IA Prepayment
Percentage" and "Group IIA Prepayment Percentage" in each of the months of the
fifth through ninth anniversaries of the first Distribution Date will be as
follows: for any Distribution Date in or after the month of the fifth
anniversary of the month of the first Distribution Date but before the sixth
anniversary of the month of the first Distribution Date, the Group IA or Group
IIA Percentage, as applicable, for such Distribution Date plus 70% of the
Subordinate Percentage for the related Certificate Group for such Distribution
Date; for any Distribution Date in or after the month of the sixth anniversary
of the month of the first Distribution Date but before the seventh anniversary
of the month of the first Distribution Date, the Group IA or Group IIA
Percentage, as applicable, for such Distribution Date plus 60% of the
Subordinate Percentage for the related Certificate Group for such Distribution
Date; for any Distribution Date in or after the month of the seventh anniversary
of the month of the first Distribution Date but before the eighth anniversary of
the month of the first Distribution Date, the Group IA or Group IIA Percentage,
as applicable, for such Distribution Date plus 40% of the Subordinate Percentage
for the related Certificate Group for such Distribution Date; for any
Distribution Date in or after the month of the eighth anniversary of the month
of the first Distribution Date but before the ninth anniversary of the month of
the first Distribution Date, the Group IA or Group IIA Percentage, as
applicable, for such Distribution Date plus 20% of the Subordinate Percentage
for the related Certificate Group for such Distribution Date. For any
Distribution Date in or after the ninth anniversary of the month of the first
Distribution Date, the Group IA or Group IIA Prepayment Percentage will be the
Group IA or Group IIA Percentage, respectively, for such Distribution Date.
 
    Notwithstanding the foregoing, if on any Distribution Date the Group IA or
Group IIA Percentage for such Distribution Date exceeds the initial Group IA or
Group IIA Percentage, respectively, as of the Cut-Off Date, then the Group IA or
Group IIA Prepayment Percentage, as applicable, for such Distribution Date will
equal 100%. The scheduled reductions in the Group IA and Group IIA Prepayment
Percentages for Distribution Dates occurring on or after the fifth anniversary
of the month of the first Distribution Date will be subject to certain
conditions specified in the Pooling Agreement. Such conditions may include
requirements that no such reduction may occur if delinquencies or losses on the
Mortgage Loans in the related Loan Group exceed specified limits at the time of,
or on a date preceding, the Distribution Date for which such reduction would
otherwise be applicable. Notwithstanding the foregoing, on any Distribution Date
if the delinquencies or losses on the Mortgage Loans in a Loan Group exceed such
limits such that the Pooling Agreement restricts a reduction of the Group IA or
Group IIA Prepayment Percentage, then the Group IA or Group IIA Prepayment
Percentage, as applicable, for such Distribution Date will equal 100% for such
Distribution Date. If on any Distribution Date the allocation to the Class R
Certificates and the Group I Certificates that are Senior Certificates (other
than the Class IP Certificates) or the allocation to the Group II Certificates
that are Senior Certificates (other than the PO Component of the Class IIA-1
Certificates) in the percentage required would reduce the sum of the Class
Principal Balances of such Certificates below zero, the Group IA or Group IIA
Prepayment Percentage, as applicable, for such Distribution Date will be limited
to the percentage necessary to reduce such sum to zero.
 
    The "Class IA-3 Prepayment Percentage" will equal the product of (a) the
Class IA-3 Percentage and (b) the Step Down Percentage (as defined below).
 
    The "Class IIA-4 Prepayment Percentage" will equal the product of (a) the
Class IIA-4 Percentage and (b) the Step Down Percentage.
 
                                      S-69
<PAGE>
    The "Step Down Percentage" for any Distribution Date will be the percentage
indicated below:
 
<TABLE>
<CAPTION>
DISTRIBUTION DATE OCCURRING IN                                             STEP DOWN PERCENTAGE
- ------------------------------------------------------------------------  -----------------------
<S>                                                                       <C>
May 1997 through April 2002.............................................                 0%
May 2002 through April 2003.............................................                30%
May 2003 through April 2004.............................................                40%
May 2004 through April 2005.............................................                60%
May 2005 through April 2006.............................................                80%
May 2006 and thereafter.................................................               100%
</TABLE>
 
CROSS-COLLATERALIZATION
 
    Special Hazard Losses (up to the Special Hazard Coverage) incurred in a Loan
Group will be allocated to the Class of Subordinate Certificates then
outstanding, regardless of Certificate Group, which has the lowest priority of
payment (the "Lowest Class"); PROVIDED, HOWEVER, that in the event any Special
Hazard Loss is incurred with respect to a Class IP Mortgage Loan or a PO
Component Mortgage Loan, the applicable Class IP Fraction or PO Component
Fraction (each as defined herein) of such loss will first be allocated to such
Class IP Mortgage Loan or PO Component Mortgage Loan and the remainder of such
loss will be allocated as described above. The Special Hazard Coverage as of the
Closing Date will be $5,110,303. If at the time of the allocation of such
Special Hazard Losses there is more than one Lowest Class of Subordinate
Certificates outstanding, allocation of such Special Hazard Loss will be made on
a pro rata basis to such Lowest Classes, based on their respective Class
Principal Balances. In addition, all or a portion of the payments of principal
otherwise distributable to the Lowest Class of the unrelated Certificate Group
will be transferred to the Certificate Group relating to the Loan Group which
incurred the Special Hazard Loss up to the amount of the loss allocated to such
unrelated Lowest Class. The Certificate Group from which funds were transferred
is the "Transferor Group" and the Certificate Group which receives such funds is
the "Transferee Group". If the amount of principal payments otherwise
distributable to the Lowest Class of a Transferor Group is less than the amount
of the allocation of the Special Hazard Loss to such Lowest Class, such
shortfall will constitute a "Transfer Balance". The Distribution Date on which a
Transfer Balance is created for a Certificate Group is referred to as a "Cross-
Collateralization Date".
 
    The Transfer Balance will represent a claim on the Available Distribution
Amount for such Transferor Group which will be payable on future Distribution
Dates to the Certificates of the applicable Transferee Group. The Transfer
Balance will be treated as if it were a Subordinate Certificate of the
applicable Transferor Group, of the same rating and Class designation as the
lowest rated Subordinate Certificate in such Transferor Group. The Transfer
Balance will bear interest at the weighted average Remittance Rate applicable
from time to time to the Certificate or Certificates in the related Transferee
Group, and accrued interest thereon will be payable to the Certificates of the
applicable Transferee Group on each Distribution Date concurrently with
distributions of interest on the related Lowest Class in the Transferor Group.
Such accrued interest will be subject to reduction for Prepayment Interest
Shortfalls applicable to such Transferor Group.
 
    Distributions in respect of principal of a Transfer Balance will be made on
each Distribution Date to the Certificates of the applicable Transferee Group
out of amounts that would otherwise be distributions of principal of the Lowest
Class in the applicable Transferor Group. In addition, a Transfer Balance will
be reduced concurrently and on a pro rata basis with any other reductions in the
Class Principal Balance of the Lowest Class in the applicable Transferor Group.
 
    For purposes of calculating the Group IA Percentage and Group IIA Percentage
(and thus the Group IA and Group IIA Prepayment Percentages and Subordinate
Percentages) of a Transferor Group on any Distribution Date on which there is a
related Transfer Balance, the Group IA and Group IIA Percentages will be the
percentage equivalent of a fraction, the numerator of which is the sum of the
Class Principal Balances of the Class or Classes of Senior Certificates in such
Transferor Group (other than the
 
                                      S-70
<PAGE>
Class IP Certificates or PO Component of the Class IIA-1 Certificates, as
applicable), and the denominator of which is the sum of (x) the Class Principal
Balances of all Classes of Certificates in such Transferor Group (other than the
Class IP Certificates or PO Component of the Class IIA-1 Certificates, as
applicable) and (y) such Transfer Balance.
 
    For the purposes of calculating the Class IA-3 Percentage and Class IIA-4
Percentage (and thus the Class IA-3 and Class IIA-4 Prepayment Percentages) on
any Distribution Date on which there is a Transfer Balance in the applicable
Certificate Group, the Group IA-3 and Class IIA-4 Percentages will be the
percentage equivalent of a fraction, the numerator of which is the Class IA-3 or
Class IIA-4 Principal Balance, as applicable, and the denominator of which is
the sum of (x) the Class Principal Balances of all Classes of Certificates in
such Certificate Group (other than the Class IP Certificates or PO Component of
the Class IIA-1 Certificates, as applicable) and (y) such Transfer Balance.
 
    It is expected that transfers in respect of Special Hazard Losses will occur
and that Transfer Balances will be created.
 
SUBORDINATION AND ALLOCATION OF LOSSES
 
    The Class B Certificates of each Certificate Group will be subordinate in
right of payment to and provide credit support to the Senior Certificates of
such Certificate Group, the Junior Subordinate Certificates of each Certificate
Group will be subordinate in right of payment to and provide credit support to
the Senior Subordinate Certificates of such Certificate Group and each Class of
Senior Subordinate Certificates in each Certificate Group will be subordinate in
right of payment to and provide credit support to each Class of Senior
Subordinate Certificates of such Certificate Group with a lower numerical Class
designation. The support provided by the Class B Certificates of each
Certificate Group is intended to enhance the likelihood of regular receipt by
the Senior Certificates of such Certificate Group of the full amount of the
monthly distributions of interest (except the Class IP Certificates and the PO
Component of the Class IIA-1 Certificates, which are not entitled to interest)
and principal (except the Class X Certificates and the IO Component of the Class
IIA-1 Certificates, which are not entitled to principal) to which they are
entitled and to afford such Certificates protection against certain losses. The
protection afforded to the Senior Certificates of each Certificate Group by the
Class B Certificates of such Certificate Group will be accomplished by the
preferential right on each Distribution Date of such Senior Certificates to
receive distributions of interest (except the Class IP Certificates and the PO
Component of the Class IIA-1 Certificates) and principal (except the Class X
Certificates and the IO Component of the Class IIA-1 Certificates) prior to
distributions of interest or principal to such Class B Certificates. The support
provided by the Junior Subordinate Certificates of each Certificate Group to the
Senior Subordinate Certificates of such Certificate Group is intended to enhance
the likelihood of regular receipt by such Senior Subordinate Certificates of the
full amount of monthly distributions of interest and principal to which they are
entitled and to afford such Certificateholders protection against certain
losses. The protection afforded to the Senior Subordinate Certificates of each
Certificate Group by the Junior Subordinate Certificates of such Certificate
Group will be accomplished by the preferential right on each Distribution Date
of such Senior Subordinate Certificates to receive distributions of interest and
principal, prior to distributions of interest and principal to such Junior
Subordinate Certificates.
 
    Except for all Special Hazard Losses and for Fraud Losses and Bankruptcy
Losses in excess of the designated amounts of Group I Fraud Coverage and Group I
Bankruptcy Coverage (each, as defined herein), any loss realized with respect to
a Group I Loan will be allocated among the Group I Certificates and the Class R
Certificates (i) for losses allocable to principal (a) first, to the Group I
Junior Subordinate Certificates, until the aggregate of the Class Principal
Balances thereof has been reduced to zero, (b) second, to the Class IB-3
Certificates, until the Class IB-3 Principal Balance has been reduced to zero,
(c) third, to the Class IB-2 Certificates, until the Class IB-2 Principal
Balance has been reduced to zero, (d) fourth, to the Class IB-1 Certificates,
until the Class IB-1 Principal Balance has been reduced to zero and (e) fifth,
to the Group IA and Class R Certificates, pro rata, according to their Class
Principal Balances (or Component Balances in the case of the PAC Component and
Companion Component of the
 
                                      S-71
<PAGE>
Class IA-1 Certificates and the PAC Component and TAC Component of the Class
IA-2 Certificates) in reduction of their respective Class Principal or Component
Balances, as applicable, PROVIDED, HOWEVER, that if the loss is recognized with
respect to a Class IP Mortgage Loan, the Class IP Fraction of such loss will
first be allocated to the Class IP Certificates and the remainder of such loss
will be allocated as described above in this clause (i); and (ii) for losses
allocable to interest (a) first, to the Group I Junior Subordinate Certificates,
in reduction of accrued but unpaid interest thereon and then in reduction of the
Class Principal Balances of the Classes of Group I Junior Subordinate
Certificates, (b) second, to the Class IB-3 Certificates, in reduction of
accrued but unpaid interest thereon and then in reduction of the Class IB-3
Principal Balance, (c) third, to the Class IB-2 Certificates, in reduction of
accrued but unpaid interest thereon and then in reduction of the Class IB-2
Principal Balance, (d) fourth, to the Class IB-1 Certificates, in reduction of
accrued but unpaid interest thereon and then in reduction of the Class IB-1
Principal Balance and (e) fifth, to the Group IA, Class IX and Class R
Certificates, pro rata according to accrued but unpaid interest thereon and then
pro rata according to their Class Principal Balances (or Component Balances in
the case of the PAC Component and Companion Component of the Class IA-1
Certificates and the PAC Component and TAC Component of the Class IA-2
Certificates) in reduction of their respective Class Principal or Component
Balances, as applicable.
 
    Except for all Special Hazard Losses and for Fraud Losses and Bankruptcy
Losses in excess of the designated amounts of Group II Fraud Coverage and Group
II Bankruptcy Coverage (each, as defined herein), any loss realized with respect
to a Group II Loan will be allocated among the Group II Certificates (i) for
losses allocable to principal (a) first, to the Group II Junior Subordinate
Certificates, until the aggregate of the Class Principal Balances thereof has
been reduced to zero, (b) second, to the Class IIB-3 Certificates, until the
Class IIB-3 Principal Balance has been reduced to zero, (c) third, to the Class
IIB-2 Certificates, until the Class IIB-2 Principal Balance has been reduced to
zero, (d) fourth, to the Class IIB-1 Certificates, until the Class IIB-1
Principal Balance has been reduced to zero and (e) fifth, to the Group IIA
Certificates, pro rata, according to their Class Principal Balances (or the PAC
Component Balance and TAC Component Balance in the case of the Class IIA-1
Certificates) in reduction of their respective Class Principal or Component
Balances, as applicable; PROVIDED, HOWEVER, that if the loss is recognized with
respect to a PO Component Mortgage Loan, the PO Component Fraction of such loss
will first be allocated to the PO Component of the Class IIA-1 Certificates and
the remainder of such loss will be allocated as described above in this clause
(i); and (ii) for losses allocable to interest (a) first, to the Group II Junior
Subordinate Certificates, in reduction of accrued but unpaid interest thereon
and then in reduction of the Class Principal Balances of the Classes of Group II
Junior Subordinate Certificates, (b) second, to the Class IIB-3 Certificates, in
reduction of accrued but unpaid interest thereon and then in reduction of the
Class IIB-3 Principal Balance, (c) third, to the Class IIB-2 Certificates, in
reduction of accrued but unpaid interest thereon and then in reduction of the
Class IIB-2 Principal Balance, (d) fourth, to the Class IIB-1 Certificates, in
reduction of accrued but unpaid interest thereon and then in reduction of the
Class IIB-1 Principal Balance and (e) fifth, to the Group IIA (other than the PO
Component of the Class IIA-1 Certificates) and Class IIX Certificates, pro rata
according to accrued but unpaid interest thereon and then pro rata according to
their Class Principal Balances (or Component Balances in the case of the PAC
Component and TAC Component of the IIA-1 Certificates) in reduction of their
respective Class Principal or Component Balances, as applicable.
 
    Special Hazard Losses incurred on a Mortgage Loan in either Loan Group up to
the Special Hazard Coverage will be allocated (i) first, to the Lowest Class of
Subordinate Certificates outstanding, regardless of Certificate Group, or, if
there are both Class IB and Class IIB Certificates outstanding with the same
lowest rating, then pro rata to such Lowest Classes according to their
respective Class Principal Balances, (ii) second, to the next Lowest Class or
Classes of Subordinate Certificates outstanding, in the manner described in
clause (i) above until the Class Principal Balances of all of the Subordinate
Certificates have been reduced to zero, and (iii) third, to the Senior
Certificates related to the Loan Group in which the loss occurred, by Pro Rata
Allocation (as defined below); PROVIDED, HOWEVER, that in the event any Special
Hazard Loss is incurred with respect to a Class IP Mortgage Loan or a PO
Component Mortgage Loan,
 
                                      S-72
<PAGE>
the applicable Class IP Fraction or PO Component Fraction (each as defined
herein) of such loss will first be allocated to such Class IP Mortgage Loan or
PO Component Mortgage Loan and the remainder of such loss will be allocated as
described above. See "-- Cross-Collateralization" herein.
 
    The allocation of the principal portion of losses relating to a Mortgage
Loan in a given Loan Group to all Classes of Certificates in the related
Certificate Group (other than the Class IP Certificates in the case of a Group I
Loan and the PO Component of the Class IIA-1 Certificates in the case of a Group
II Loan) pro rata according to their respective Class Principal or Component
Balances (except if the loss is recognized with respect to a Class IP Mortgage
Loan or PO Component Mortgage Loan, in which event the Class IP Fraction or PO
Component Fraction, of such loss will first be allocated to the Class IP
Certificates or PO Component of the Class IIA-1 Certificates, respectively, and
the remainder of such loss will be allocated as described above), and the
allocation of the interest portion of such losses to the Certificates in the
related Certificate Group pro rata according to the amount of interest accrued
on each such Class or Component (other than the Class IP Certificates in the
case of a Group I Loan and the PO Component of the Class IIA-1 Certificates in
the case of a Group II Loan) in reduction thereof and then in reduction of their
related Class Principal or Component Balances, is hereinafter referred to as
"Pro Rata Allocation". For the purpose of allocating losses in Loan Group I to
the outstanding Classes of Group I Certificates by Pro Rata Allocation, the
Class R Certificates are deemed to be Group I Certificates.
 
    On each Distribution Date, after giving effect to the principal
distributions and allocations of losses described above, if the aggregate
Certificate Principal Balance of all outstanding Certificates in a Certificate
Group exceeds the sum of (i) the aggregate principal balance of the Mortgage
Loans in the related Loan Group (giving effect for each such Mortgage Loan to
all amounts of principal in respect of such Mortgage Loan that have been
received or advanced and included in the Available Distribution Amount for such
Loan Group, and all losses in respect of such Mortgage Loans that have been
allocated to Certificates, on Distribution Dates on or before such Distribution
Date) and (ii) any Transfer Balance owing to such Certificate Group, that excess
will be deemed a principal loss and will be allocated to the most junior Class
of Subordinate Certificates in such Certificate Group.
 
    Special Hazard Losses incurred on a Group I Loan in excess of the Special
Hazard Coverage will be allocated to the outstanding Classes of Group I
Certificates by Pro Rata Allocation. Special Hazard Losses incurred on a Group
II Loan in excess of the Special Hazard Coverage will be allocated to the
outstanding Classes of Group II Certificates by Pro Rata Allocation. "Special
Hazard Coverage" is expected to equal approximately $5,110,303 as of the Cut-Off
Date. On each anniversary of the Cut-Off Date, the Special Hazard Coverage will
be reduced, but not increased, to an amount equal to the lesser of (1) the
greatest of (a) the aggregate principal balance of the Mortgage Loans located in
the single California zip code area containing the largest aggregate principal
balance of the Mortgage Loans, (b) 1% of the aggregate unpaid principal balance
of the Mortgage Loans and (c) twice the unpaid principal balance of the largest
single Mortgage Loan, in each case calculated as of the Due Date in the
immediately preceding month and (2) the Special Hazard Coverage as of the
Cut-Off Date as reduced by the Special Hazard Losses allocated to the
Certificates since the Cut-Off Date.
 
    Fraud Losses incurred on a Mortgage Loan in excess of the Fraud Coverage for
the related Loan Group will be allocated to the outstanding Classes of
Certificates in the related Certificate Group by Pro Rata Allocation. "Group I
Fraud Coverage" is expected to equal approximately $1,519,811 as of the Cut-Off
Date. "Group II Fraud Coverage" is expected to equal approximately $7,180,984 as
of the Cut-Off Date. Fraud Coverage for a Loan Group will be reduced, from time
to time, by the amount of Fraud Losses allocated to the Certificates of the
related Certificate Group. On each anniversary of the Cut-Off Date, Fraud
Coverage for a Loan Group will be reduced to the lesser of (i) on the first,
second, third and fourth anniversaries of the Cut-Off Date, 1.0% of the
aggregate principal balance of the Mortgage Loans in the related Loan Group as
of the Due Date in the preceding month and (ii) the excess of the Fraud Coverage
for such Loan Group as of the Cut-Off Date over cumulative Fraud Losses
allocated to the Certificates in such Certificate Group to date. On the fifth
anniversary of the Cut-Off Date, Fraud Coverage will be reduced to zero.
 
                                      S-73
<PAGE>
    Bankruptcy Losses incurred on a Mortgage Loan in excess of the Bankruptcy
Coverage for the related Loan Group will be allocated to the outstanding Classes
of Certificates in the related Certificate Group by Pro Rata Allocation. "Group
I Bankruptcy Coverage" is expected to equal approximately $100,000 as of the
Cut-Off Date. "Group II Bankruptcy Coverage" is expected to equal approximately
$125,886 as of the Cut-Off Date. Bankruptcy Coverage for a Loan Group will be
reduced, from time to time, by the amount of Bankruptcy Losses allocated to the
Certificates in the related Certificate Group.
 
    Special Hazard Coverage, Fraud Coverage or Bankruptcy Coverage may also be
reduced upon written confirmation from the Rating Agencies that such reduction
will not adversely affect the then current ratings assigned to the Offered
Certificates by the Rating Agencies. Such a reduction, in the event of Special
Hazard Losses, Fraud Losses or Bankruptcy Losses, could adversely affect the
level of protection afforded the Senior Certificates by subordination of the
Class B Certificates or the level of protection afforded the Senior Subordinate
Certificates by the Junior Subordinate Certificates.
 
    Investors in the Senior Certificates should be aware that the coverage for
Special Hazard Losses covers Mortgage Loans in both Loan Groups. Therefore, in
the event Mortgage Loans in a Loan Group suffer a high level of Special Hazard
Losses, it will reduce the available coverage for the Senior Certificates of
both Certificate Groups and also will cause Senior Certificates of a Certificate
Group to suffer losses in the event Mortgage Loans in the related Loan Group
suffer such losses after the available coverage has been exhausted,
notwithstanding minimal Special Hazard Losses in such Loan Group prior thereto.
 
THE CLASS R CERTIFICATES
 
    On each Distribution Date, in addition to payments of interest and principal
to the Class R Certificates described herein, any amounts remaining in the
Certificate Account from the Available Distribution Amount after distributions
of interest and principal on the Certificates and payment of expenses, if any,
of the Trust will be distributed to the Class R Certificateholders, together
with Excess Liquidation Proceeds (as defined below), if any. Distributions of
such remaining amounts to the Class R Certificateholders will be subordinate to
all payments required to be made with respect to the other Offered Certificates
on any Distribution Date.
 
    Any amounts remaining in the Certificate Account upon reduction of the
aggregate Certificate Principal Balance to zero, payment of any outstanding
expenses and termination of the Trust will be distributable to the Class R
Certificateholders. Such remaining assets are expected to be minimal. See "--
Optional Termination of the Trust" herein.
 
ADVANCES
 
    With respect to each Mortgage Loan, the Master Servicer will make Advances
to the Certificate Account on each Distribution Date to cover any shortfall
between (i) payments scheduled to be received in respect of such Mortgage Loan
and (ii) the amounts actually deposited in the Certificate Account on account of
such payments; provided that the Master Servicer determines, in good faith, on
such Distribution Date that such Advances will be recoverable from Insurance
Proceeds, Liquidation Proceeds or other amounts received with respect to such
Mortgage Loan. Advances are reimbursable to the Master Servicer from cash in the
Certificate Account prior to payments to the Certificateholders if the Master
Servicer determines that such Advances previously made are not recoverable from
Insurance Proceeds, Liquidation Proceeds or other amounts recoverable with
respect to the applicable Mortgage Loan.
 
AVAILABLE DISTRIBUTION AMOUNT
 
    On each Distribution Date, the Available Distribution Amount for any
Distribution Date will be determined separately with respect to Loan Group I and
Loan Group II, and, in each case, will generally include scheduled principal and
interest payments due on the related Due Date, Curtailments received in the
previous calendar month (as set forth below), Payoffs received in the applicable
period to the extent set
 
                                      S-74
<PAGE>
forth below and amounts received with respect to liquidations of Mortgage Loans
with respect to such Loan Group in the previous calendar month, will be
distributed by or on behalf of the Trustee to the Certificateholders, as
specified herein.
 
    The Due Date related to each Distribution Date is the first day of the month
in which such Distribution Date occurs. The determination date (the
"Determination Date") is a day not later than the 10th day preceding the related
Distribution Date in the month in which such Distribution Date occurs.
 
    The "Available Distribution Amount" for any Distribution Date for each Loan
Group, as more fully described in the Pooling Agreement, will equal the sum,
with respect to the Mortgage Loans in such Loan Group, of the following amounts:
 
        (1) the total amount of all cash received by or on behalf of the Master
    Servicer with respect to the Mortgage Loans by the Determination Date for
    such Distribution Date and not previously distributed (including advances
    made by servicers, proceeds of liquidated Mortgage Loans, and scheduled
    amounts of distributions from Buydown Funds respecting Buydown Loans, if
    any), except:
 
           (a) all scheduled payments of principal and interest collected but
       due on a date subsequent to the related Due Date;
 
           (b) all Curtailments received after the previous calendar month
       (together with any interest payment received with such prepayments to the
       extent that it represents the payment of interest accrued on the Mortgage
       Loans for the period subsequent to the previous calendar month);
 
           (c) all Payoffs received on or after the 15th day of the month of any
       such Determination Date (together with any interest payment received with
       such Payoffs to the extent that it represents the payment of interest
       accrued on the Mortgage Loans for the period subsequent to the previous
       calendar month), and interest which was accrued and received on Payoffs
       received during the period from the first to the 14th day of the month of
       such Determination Date, which interest shall not be included in the
       calculation of the Available Distribution Amount for any Distribution
       Date;
 
           (d) Liquidation Proceeds and Insurance Proceeds received after the
       previous calendar month;
 
           (e) all amounts in the Certificate Account which are due and
       reimbursable to a servicer or the Master Servicer pursuant to the terms
       of the Pooling Agreement;
 
           (f) the sum of the Servicing Fee and the Master Servicing Fee for
       each Mortgage Loan in such Loan Group; and
 
           (g) the excess, if any, of aggregate Liquidation Proceeds received
       during the previous calendar month over the amount that would have been
       received if Payoffs had been made with respect to the related Mortgage
       Loans on the date such Liquidation Proceeds were received ("Excess
       Liquidation Proceeds");
 
        (2) the total, to the extent not previously distributed, of the
    following amounts, to the extent advanced or received, as applicable, by the
    Master Servicer:
 
           (a) all Advances made by the Master Servicer to the Trustee with
       respect to such Distribution Date relating to the Mortgage Loans; and
 
           (b) any amounts payable as Compensating Interest on such Distribution
       Date relating to the Mortgage Loans; and
 
        (3) the total amount of any cash received by the Trustee or the Master
    Servicer in respect of the obligation of the Company to repurchase a
    Mortgage Loan.
 
                                      S-75
<PAGE>
    Notwithstanding the foregoing, after a Cross-Collateralization Date, the
Available Distribution Amount otherwise distributable to the Certificates of a
Transferor Group will be reduced to the extent described herein under "--
Cross-Collateralization" by any amount payable therefrom in respect of a
Transfer Balance for such Transferor Group, and the amount of such payment will
increase the Available Distribution Amount distributable to the Transferee
Group.
 
LAST SCHEDULED DISTRIBUTION DATE
 
    The Last Scheduled Distribution Date for all Classes of Certificates is May
25, 2027, which is the Distribution Date in the month after the scheduled
maturity date for the latest maturing Mortgage Loan in the Mortgage Pool.
 
    The actual rate of principal payments on the Certificates will depend on the
rate of payments of principal (including Principal Prepayments) on the Mortgage
Loans which, in turn, may be influenced by a variety of economic, geographic and
social factors, as well as the level of prevailing interest rates. No assurance
can be given as to the actual payment experience on the Mortgage Loans.
 
OPTIONAL TERMINATION OF THE TRUST
 
    On any Distribution Date after the first date on which the aggregate
outstanding principal balance of the Mortgage Loans is less than 10% of the
aggregate principal balance of the Mortgage Loans as of the Cut-Off Date, the
Company may repurchase the Mortgage Loans and all property acquired in respect
of any Mortgage Loan remaining in the Trust, and thereby effect the termination
of the Trust and the retirement of the Certificates. The repurchase price will
equal, after deductions of related advances by the Master Servicer, the sum of
(1) 100% of the aggregate outstanding principal balance of such Mortgage Loans
(other than Liquidated Mortgage Loans), plus accrued interest thereon at the
applicable Pass-Through Rates through the last day of the month of such
repurchase, less any Bankruptcy Losses realized with respect to the Mortgage
Loans for purposes of distributions to Certificateholders and (2) the fair
market value of all other property remaining in the Trust. The proceeds of such
repurchase will be treated as a prepayment of the Mortgage Loans for purposes of
distributions to Certificateholders. Accordingly, an optional termination of the
Trust will cause the outstanding principal balance of the Certificates to be
paid in full through the distribution of such proceeds and the allocation of the
associated realized losses, if any, on each Mortgaged Property in the Trust the
fair market value of which is less than the aggregate principal balance of the
related Mortgage Loans as of the time that the Trust acquired such Mortgaged
Property, and upon such payment in full the Trust will be terminated. In no
event will the Trust continue beyond the expiration of 21 years from the death
of the survivor of certain persons identified in the Pooling Agreement. See
"Description of Certificates -- Termination" in the Prospectus.
 
SERVICING COMPENSATION AND PAYMENT OF EXPENSES
 
    The Servicing Fee with respect to each Group I Loan will be 0.250%. The
Servicing Fee with respect to each Group II Loan ranges from a minimum of 0.150%
to a maximum of 0.250%, with a weighted average of 0.248%. The Master Servicing
Fee with respect to each Group I Loan will be 0.040%. The Master Servicing Fee
with respect to each Group II Loan ranges from a minimum of 0.040% to a maximum
of 0.100%, with a weighted average of 0.042%. See "Description of Certificates
- -- Servicing Compensation and Payment of Expenses" in the Prospectus for
information regarding other possible compensation to the Company and the
servicers.
 
    The Company, as Master Servicer, will pay all expenses incurred in
connection with its responsibilities under the Pooling Agreement (subject to
reimbursement as described in the Prospectus), including, without limitation,
the various items of expense enumerated in the Prospectus. In particular,
pursuant to the Pooling Agreement, each month or year, as applicable, the Master
Servicer will be obligated to pay
 
                                      S-76
<PAGE>
from the Master Servicing Fee the fees of the Trustee and certain other fees and
expenses of the Trust, as prescribed by the Pooling Agreement.
 
                      YIELD AND PREPAYMENT CONSIDERATIONS
 
GENERAL
 
    The effective yield to maturity of each Class of Certificates will depend
upon, among other things, the price at which such Certificates are purchased,
the applicable Remittance Rate, the actual characteristics of the Mortgage Loans
in the related Loan Group, the rate of principal payments (including Principal
Prepayments) on the Mortgage Loans in the related Loan Group and the rate of
liquidations on the Mortgage Loans in the related Loan Group. The effective
yield to maturity to holders of the Certificates will be lower than the yield to
maturity otherwise produced by the applicable Remittance Rate and purchase price
of such Certificates because principal and interest distributions will not be
payable to such Certificateholders until the 25th day of the month following the
month of accrual (without any additional distribution of interest or earnings
thereon with respect to such delay). Except in limited circumstances, as
described herein, distributions to the Group I Certificates and Group II
Certificates relate to payments on the Group I Loans and Group II Loans,
respectively.
 
PRINCIPAL PREPAYMENTS AND COMPENSATING INTEREST
 
    When a Mortgagor prepays a Mortgage Loan in full between Due Dates for such
Mortgage Loan, the Mortgagor pays interest on the amount prepaid only to the
date of prepayment instead of for the entire month. Also, when a Curtailment is
made on a Mortgage Loan together with the scheduled Monthly Payment for a month
on or after the related Due Date, the principal balance of the Mortgage Loan is
reduced by the amount of the Curtailment as of such Due Date, but such principal
is not distributed to related Certificateholders until the Distribution Date in
the next month; therefore, one month of interest shortfall accrues on the amount
of such Curtailment.
 
    In order to reduce the adverse effect on Certificateholders from the
deficiency in interest payable as a result of a Payoff on a Mortgage Loan
between its Due Dates, the Master Servicer will pass through Compensating
Interest to the related Certificateholders to the limited extent and in the
manner set forth below. Payoffs received from the first day through the 14th day
of any month will be passed through to related Certificateholders on the
Distribution Date of the same month (except for Payoffs received from the
Cut-Off Date through April 14, 1997, which will be passed through to holders of
related Certificates on the May 1997 Distribution Date), rather than on the
Distribution Date of the following month, together with a full month's interest
with respect to the prior month. Accordingly, no Compensating Interest will be
payable with respect to Payoffs received during such period. Payoffs received
during the period from the 15th day through the last day of any month will be
passed through on the Distribution Date in the following month, and, in order to
provide for a full month's interest payment with respect to the prior month,
Compensating Interest will be passed through to related Certificateholders with
respect to such period.
 
    The amount available for payment of Compensating Interest on any
Distribution Date will include interest at the Pass-Through Rate to the extent
of interest payments paid by Mortgagors on Payoffs received from the first
through the 14th day of the month of such Distribution Date. To the extent that
the amount available to pay Compensating Interest is insufficient to cover the
deficiency in interest payable as a result of a Payoff on a Mortgage Loan, or to
the extent that there is an interest deficiency from a Curtailment, such
remaining deficiency will be allocated to the related Certificates pro rata
according to the amount of interest to which each related Class of Certificates
would otherwise be entitled in reduction thereof.
 
                                      S-77
<PAGE>
LOCKOUT CERTIFICATES
 
    Investors in the Lockout Certificates should be aware that because the Class
IA-3 and Class IIA-4 Certificates will generally not be entitled to receive any
distributions of Principal Prepayments until May 2002, the weighted average
lives of the Lockout Certificates will be longer than would otherwise be the
case, and the effect on the market value of the Lockout Certificates arising out
of changes in market interest rates or market yields for similar securities will
be greater than for other Classes of Class A Certificates entitled to such
distributions.
 
RATE OF PAYMENTS
 
    The rate of principal payments on the Certificates entitled to receive
principal generally is directly related to the rate of principal payments on the
Mortgage Loans in the related Loan Group, which may be in the form of scheduled
payments or Principal Prepayments. See "Risk Factors" herein and "Yield
Considerations" in the Prospectus. Mortgagors may prepay the Mortgage Loans at
any time without penalty. A higher than anticipated rate of Principal
Prepayments would reduce the aggregate principal balance of the Mortgage Loans
more quickly than expected. As a consequence, aggregate interest payments with
respect to the Mortgage Loans would be substantially less than expected.
Therefore, a higher rate of Principal Prepayments in a Loan Group could result
in a lower than expected yield to maturity on each related Class of Certificates
purchased at a premium and in certain circumstances such investors may not fully
recoup their initial investments. Conversely, a lower than anticipated rate of
Principal Prepayments in a Loan Group would reduce the return to investors on
any related Classes of Certificates purchased at a discount, in that principal
payments with respect to the Mortgage Loans would occur later than anticipated.
There can be no assurance that Certificateholders will be able to reinvest
amounts received with respect to the Certificates at a rate which is comparable
to the applicable Remittance Rate. Investors should fully consider all of the
associated risks.
 
SPECIAL SENSITIVITIES
 
    The Companion Component of the Class IA-1 Certificates will be especially
sensitive to the rate of prepayment on the Group I Loans because such Companion
Component will receive distributions of principal on any Distribution Date only
to the extent of a percentage of the Group IA Principal Distribution Amount
remaining, if any, after the Group I PACs receive principal on such Distribution
Date to the extent of their respective Planned Principal Balances. The Class
IA-7 Certificates also will be especially sensitive to the rate of prepayment on
the Group I Loans because the Class IA-7 Certificates will receive distributions
of principal on any Distribution Date only to the extent of a percentage of the
Group IA Principal Distribution Amount remaining, if any, after distributions to
the Group I PACs and the TAC Component of the Class IA-2 Certificates to the
extent of its Targeted Principal Balance. Furthermore, if the Group IA Principal
Distribution Amount on any Distribution Date is not sufficient to reduce the
Class Principal or Component Balances of the Group I PACs to their Planned
Principal Balances, the Companion Component of the Class IA-1 Certificates, the
Class IA-7 Certificates and the TAC Component of the Class IA-2 Certificates
will receive no principal distributions on such Distribution Date, and if the
Group IA Principal Distribution Amount remaining to be distributed to the TAC
Component of the Class IA-2 Certificates is not sufficient to pay such Component
to its Targeted Principal Balance, the Class IA-7 Certificates will receive no
principal distribution on such Distribution Date.
 
    The Class IIA-5 Certificates will be especially sensitive to the rate of
prepayment on the Group II Loans because the Class IIA-5 Certificates will
receive distributions of principal on any Distribution Date only to the extent
of the portion of the Group IIA Principal Distribution Amount remaining, if any,
after distributions the Group II PACs, to the extent of their respective Planned
Principal Balances, and the Group II TACs, to the extent of their respective
Targeted Principal Balances. Furthermore, if the Group IIA Principal
Distribution Amount on any Distribution Date is not sufficient to reduce the
Class Principal or Component Balances of the Group II PACs to their Planned
Principal Balances and to
 
                                      S-78
<PAGE>
reduce the Class Principal or Component Balances of the Group II TACs to their
Targeted Principal Balances, the Class IIA-5 Certificates will receive no
principal distribution on such Distribution Date.
 
BASIC PREPAYMENT ASSUMPTION
 
    Prepayments on mortgage loans are commonly measured relative to a prepayment
standard or model. The model used in this Prospectus Supplement (the "Basic
Prepayment Assumption") assumes a per annum rate of prepayment of 0.2% of the
then outstanding principal balance of a pool of mortgage loans in the first
month after formation of such pool of mortgage loans, following which, such
annual prepayment rate increases by 0.2% each month until the 30th month after
formation of such pool of mortgage loans and remains constant at 6% per annum in
the 30th month after formation of such pool of mortgage loans and in each month
thereafter. 0% of the Basic Prepayment Assumption indicates no prepayments are
received; 100% of the Basic Prepayment Assumption indicates prepayments at 1.00
times the Basic Prepayment Assumption; 105% of the Basic Prepayment Assumption
indicates prepayments at 1.05 times the Basic Prepayment Assumption; 175% of the
Basic Prepayment Assumption indicates prepayments at 1.75 times the Basic
Prepayment Assumption; 240% of the Basic Prepayment Assumption indicates
prepayments at 2.40 times the Basic Prepayment Assumption; 250% of the Basic
Prepayment Assumption indicates prepayments at 2.50 times the Basic Prepayment
Assumption; 300% of the Basic Prepayment Assumption indicates prepayments at
3.00 times the Basic Prepayment Assumption; 350% of the Basic Prepayment
Assumption indicates prepayments at 3.50 times the Basic Prepayment Assumption;
and 500% of the Basic Prepayment Assumption indicates prepayments at 5.00 times
the Basic Prepayment Assumption.
 
    The Basic Prepayment Assumption does not purport to be either an historical
description of the prepayment experience of any pool of mortgage loans or a
prediction of the anticipated rate of prepayment of any pool of mortgage loans,
including the Mortgage Pool, and there is no assurance that the Mortgage Loans
will prepay at any given percentage of the Basic Prepayment Assumption. The
actual rate of Principal Prepayments on the Mortgage Loans may be influenced by
a variety of economic, geographic, social and other factors. In general, if
prevailing interest rates fall significantly below the interest rates on the
Mortgage Loans, the Mortgage Loans are likely to be subject to higher prepayment
rates than if prevailing rates remain at or above the interest rates on the
Mortgage Loans. Conversely, if interest rates rise above the interest rates on
the Mortgage Loans, the rate of prepayment would be expected to decrease. A
comparatively low interest-rate environment may result in a higher than expected
rate of prepayments on the Mortgage Loans and an earlier than expected
retirement of the Certificates.
 
    The Company makes no representation as to the specific factors that will
affect the prepayment of the Mortgage Loans or the relative importance of such
factors. Factors not identified by the Company or discussed herein may
significantly affect the prepayment rate of the Mortgage Loans. In particular,
the Company makes no representation as to the percentage of the principal amount
of the Mortgage Loans that will be paid as of any date or as to the overall rate
of prepayment.
 
    For purposes of the tables set forth in Appendix C, it is assumed that (i)
scheduled payments on all Mortgage Loans are received on the first day of each
month beginning May 1, 1997, (ii) any Payoffs on the Mortgage Loans are received
on the last day of each month beginning in April 1997 and include 30 days of
interest thereon, (iii) there are no defaults or delinquencies on the Mortgage
Loans, (iv) optional termination of the Trust does not occur, (v) the Mortgage
Loans in each Loan Group are comprised of two subgroups of hypothetical mortgage
loans which have the common characteristics indicated:
 
                                      S-79
<PAGE>
             GROUPS OF HYPOTHETICAL MORTGAGE LOANS -- LOAN GROUP I
 
<TABLE>
<CAPTION>
   UNPAID PRINCIPAL        ORIGINAL TERM        MORTGAGE         PASS-THROUGH       REMAINING TERM
        BALANCE              (MONTHS)         INTEREST RATE          RATE              (MONTHS)
- -----------------------  -----------------  -----------------  -----------------  -------------------
<S>                      <C>                <C>                <C>                <C>
  $      5,007,274.55           180           7.1089985015%      6.8189985015%            174
  $    146,973,839.54           180           7.7510711236%      7.4610711236%            170
</TABLE>
 
             GROUPS OF HYPOTHETICAL MORTGAGE LOANS -- LOAN GROUP II
 
<TABLE>
<CAPTION>
   UNPAID PRINCIPAL        ORIGINAL TERM        MORTGAGE         PASS-THROUGH       REMAINING TERM
        BALANCE              (MONTHS)         INTEREST RATE          RATE              (MONTHS)
- -----------------------  -----------------  -----------------  -----------------  -------------------
<S>                      <C>                <C>                <C>                <C>
  $     56,768,068.29           359           7.6204791215%      7.3321940618%            357
  $    302,281,154.64           359           8.2433119749%      7.9538227283%            357
</TABLE>
 
(vi) there are no partial prepayments on the Mortgage Loans and prepayments are
computed after giving effect to scheduled payments received on the following
day, (vii) the Mortgage Loans prepay at the indicated constant percentages of
the Basic Prepayment Assumption, (viii) the date of issuance for the
Certificates is April 30, 1997, (ix) cash distributions are received by the
Certificateholders on the 25th day of each month when due and (x) the scheduled
monthly payments for each Mortgage Loan are computed based upon its unpaid
principal balance, Mortgage Interest Rate and remaining term such that the
Mortgage Loan will fully amortize on its maturity date (collectively, the
"Modeling Assumptions"). The approximate Class Principal Balances of the Junior
Subordinate Certificates as of the Cut Off-Date will be as follows: Class IB-4,
$379,952; Class IB-5, $455,943; Class IB-6, $303,965; Class IIB-4, $1,615,722;
Class IIB-5, $897,623; and Class IIB-6, $1,077,149.
 
    Any discrepancy between the actual characteristics of the Mortgage Loans and
the characteristics of the Mortgage Loans set forth above may affect the
percentages of the initial Class Principal Balances set forth in the tables and
the weighted average lives of the Offered Certificates. In addition, to the
extent that the characteristics of the Mortgage Loans differ and the initial
Class Principal Balances differ, from those assumed in preparing the tables in
Appendix C, the outstanding Class Principal Balance of any Class of Offered
Certificates may be reduced to zero earlier or later than indicated by such
tables.
 
    Variations in actual prepayment experience may increase or decrease the
percentages of the original outstanding Class Principal Balances and the
weighted average lives shown in the tables in Appendix C. Such variations may
occur even if the average prepayment experience of all the Mortgage Loans equals
the indicated percentage of the Basic Prepayment Assumption. There is no
assurance, however, that prepayment of the Mortgage Loans will conform to any
given percentage of the Basic Prepayment Assumption.
 
    Based on the foregoing assumptions, the tables in Appendix C indicate the
projected weighted average lives of the Offered Certificates and set forth the
percentages of the initial outstanding Class Principal Balance of each such
Class of Offered Certificates that would be outstanding after each of the dates
shown at various constant percentages of the Basic Prepayment Assumption.
 
YIELD CONSIDERATIONS WITH RESPECT TO THE CLASS X AND CLASS IP CERTIFICATES
 
    The yields to maturity on the Class X and Class IP Certificates will be
extremely sensitive to the level of both the timing of and overall rate of
receipt of Principal Prepayments on the Mortgage Loans in the related Loan
Group. The interest payable to the Class IX-1 Certificates is based on the
weighted average of the Stripped Interest Rates of the Class IX-1 15-Year
Premium Rate Mortgage Loans. The interest payable to the Class IX-2 Certificates
is based on the weighted average of the Stripped Interest Rates of the Class
IX-2 15-Year Premium Rate Mortgage Loans. The interest payable to the Class IIX
Certificates is based on the weighted average of the Stripped Interest Rates of
the 30-Year Premium Rate Mortgage Loans. Therefore the yield to maturity on any
Class of the Class X Certificates will generally decrease as a result of faster
than expected Principal Prepayments on the related group of Premium Rate
Mortgage
 
                                      S-80
<PAGE>
Loans. Prospective investors should fully consider the risks associated with an
investment in the Class X Certificates, including the possibility that if the
rate of Principal Prepayments on the related Premium Rate Mortgage Loans is
rapid, such investors may not fully recoup their initial investments. Because
the principal payable with respect to the Class IP Certificates (which are
entitled to receive distributions of principal only) is derived from Group I
Loans with Pass-Through Rates that are lower than 7.000%, the yield to maturity
on the Class IP Certificates will be adversely affected by slower than expected
prepayments of Group I Loans with Pass-Through Rates less than 7.000%. Because
the interest payable on the Class IX Certificates and the principal
distributable to the Class IP Certificates are derived from different groups of
Mortgage Loans within Loan Group I, it is possible that faster than expected
prepayments with respect to the Class IX Certificates may occur at the same time
as slower than expected prepayments with respect to the Class IP Certificates.
 
    To illustrate the significance of different rates of prepayment on the
distributions on the Class X and Class IP Certificates, the following tables
indicate the approximate pre-tax yields to maturity (on a corporate bond
equivalent basis) under the different percentages of the Basic Prepayment
Assumption indicated. Because the rate of distribution of interest on the Class
X Certificates and the rate of distribution of principal on the Class IP
Certificates will be directly related to the actual amortization (including
prepayments) of the Mortgage Loans, which will include Mortgage Loans that have
remaining terms to maturity shorter or longer than those assumed and interest
rates higher or lower than those assumed, the pre-tax yields to maturity on the
Class X and Class IP Certificates are likely to differ from those shown in the
following tables even if all the Mortgage Loans in the related Loan Group prepay
at the indicated constant percentages of the Basic Prepayment Assumption and the
weighted average remaining terms to maturity of the Mortgage Loans in the
related Loan Group are as assumed. Any differences between such assumptions and
the actual characteristics and performance of the Mortgage Loans and of the
Certificates may result in yields to maturity being different from those shown
in such tables. Discrepancies between assumed and actual characteristics and
performances underscore the hypothetical nature of the tables, which are
provided only to give a general sense of the sensitivity of yields to maturity
in varying prepayment scenarios. In addition, it is highly unlikely that the
Mortgage Loans will prepay at a constant level of the Basic Prepayment
Assumption until maturity or that all of such Mortgage Loans will prepay at the
same rate. The timing of changes to the rate of Principal Prepayments may
significantly affect the actual yield to maturity to an investor, even if the
average rate of Principal Prepayments is consistent with an investor's
expectation. In general, the earlier a payment of principal of the Mortgage
Loans, the greater the effect on an investor's yield to maturity. As a result,
the effect on an investor's yield to maturity of Principal Prepayments occurring
at a rate higher (or lower) than the rate anticipated by the investor during the
period immediately following the issuance of the Certificates will not be
equally offset by a subsequent like reduction (or increase) in the rate of
Principal Prepayments.
 
    In addition, the yield to maturity on the Class X Certificates may be
adversely affected if an optional termination of the Trust occurs.
 
    The sensitivity tables for the Class X and Class IP Certificates set forth
below are based on the Modeling Assumptions described on pages S-79 and S-80
except that the sensitivity tables for the Class IX-1 and Class IX-2
Certificates are based on the following subgroups of hypothetical mortgage loans
instead of those described above:
 
<TABLE>
<CAPTION>
                     UNPAID PRINCIPAL        ORIGINAL TERM        MORTGAGE         PASS-THROUGH       REMAINING TERM
                          BALANCE              (MONTHS)         INTEREST RATE          RATE              (MONTHS)
                  -----------------------  -----------------  -----------------  -----------------  -------------------
<S>               <C>                      <C>                <C>                <C>                <C>
Class IX-1:         $     64,562,405.84           179           7.6763864560%      7.3863864560%            163
Class IX-2:         $     82,411,433.70           180           7.8095802600%      7.5195802600%            175
</TABLE>
 
All of the tables assume further that the Certificates are purchased at prices
(which include accrued interest in the case of the Class X Certificates) equal
to those set forth in the tables. There can be no assurance that the Mortgage
Loans will have the assumed characteristics, will prepay at any of the rates
shown herein, that the purchase prices of the Certificates will be as assumed or
that the pre-tax yields to
 
                                      S-81
<PAGE>
maturity will correspond to any of the pre-tax yields shown herein. The actual
prices to be paid on the Class X and Class IP Certificates have not been
determined and will be dependent on the characteristics of the Mortgage Pool as
ultimately constituted. In addition to any other factors an investor may deem
material, each investor must make its own decision as to the appropriate
prepayment assumptions to be used in deciding whether or not to purchase a Class
of Certificates.
 
                    SENSITIVITY OF PRE-TAX YIELD TO MATURITY
               OF THE CLASS IX-1 CERTIFICATES TO PREPAYMENTS AT A
                            SPECIFIED ASSUMED PRICE
 
<TABLE>
<CAPTION>
                                           PERCENTAGE OF THE BASIC PREPAYMENT ASSUMPTION
                                  ---------------------------------------------------------------
ASSUMED PRICE                         0%          105%         175%         240%         300%         500%
- --------------------------------  -----------  -----------  -----------  -----------  -----------  -----------
<S>                               <C>          <C>          <C>          <C>          <C>          <C>
$839,751........................       23.6%        17.2%        12.7%         8.6%         4.6%       (9.2)%
</TABLE>
 
    On the basis of a constant prepayment rate of approximately 368% of the
Basic Prepayment Assumption, a purchase price of $839,751, which includes
accrued interest, and the assumptions described above, the pre-tax yield to
maturity of the Class IX-1 Certificates would be approximately 0%. If the actual
prepayment rate were to exceed the rates assumed above, even for one month,
while equaling such rates for all other months, an investor in the Class IX-1
Certificates would not fully recoup the initial purchase price of such
Certificates.
 
                    SENSITIVITY OF PRE-TAX YIELD TO MATURITY
               OF THE CLASS IX-2 CERTIFICATES TO PREPAYMENTS AT A
                            SPECIFIED ASSUMED PRICE
 
<TABLE>
<CAPTION>
                                           PERCENTAGE OF THE BASIC PREPAYMENT ASSUMPTION
                                  ---------------------------------------------------------------
ASSUMED PRICE                         0%          105%         175%         240%         300%         500%
- --------------------------------  -----------  -----------  -----------  -----------  -----------  -----------
<S>                               <C>          <C>          <C>          <C>          <C>          <C>
$1,686,097......................       19.3%        13.9%        10.2%         6.7%         3.4%       (7.9)%
</TABLE>
 
    On the basis of a constant prepayment rate of approximately 361% of the
Basic Prepayment Assumption, a purchase price of $1,686,097, which includes
accrued interest, and the assumptions described above, the pre-tax yield to
maturity of the Class IX-2 Certificates would be approximately 0%. If the actual
prepayment rate were to exceed the rates assumed above, even for one month,
while equaling such rates for all other months, an investor in the Class IX-2
Certificates would not fully recoup the initial purchase price of such
Certificates.
 
                    SENSITIVITY OF PRE-TAX YIELD TO MATURITY
               OF THE CLASS IIX CERTIFICATES TO PREPAYMENTS AT A
                            SPECIFIED ASSUMED PRICE
 
<TABLE>
<CAPTION>
                                           PERCENTAGE OF THE BASIC PREPAYMENT ASSUMPTION
                                  ---------------------------------------------------------------
ASSUMED PRICE                         0%          100%         175%         250%         350%         500%
- --------------------------------  -----------  -----------  -----------  -----------  -----------  -----------
<S>                               <C>          <C>          <C>          <C>          <C>          <C>
$1,967,212......................       20.6%        15.3%        11.2%         7.1%         1.6%       (7.0)%
</TABLE>
 
    On the basis of a constant prepayment rate of approximately 377% of the
Basic Prepayment Assumption, a purchase price of $1,967,212, which includes
accrued interest, and the assumptions described above, the pre-tax yield to
maturity of the Class IIX Certificates would be approximately 0%. If the actual
prepayment rate were to exceed the rates assumed above, even for one month,
while equaling such rates for all other months, an investor in the Class IIX
Certificates would not fully recoup the initial purchase price of such
Certificates.
 
                                      S-82
<PAGE>
                    SENSITIVITY OF PRE-TAX YIELD TO MATURITY
                OF THE CLASS IP CERTIFICATES TO PREPAYMENTS AT A
                            SPECIFIED ASSUMED PRICE
 
<TABLE>
<CAPTION>
                                           PERCENTAGE OF THE BASIC PREPAYMENT ASSUMPTION
                                  ---------------------------------------------------------------
ASSUMED PRICE                         0%          105%         175%         240%         300%         500%
- --------------------------------  -----------  -----------  -----------  -----------  -----------  -----------
<S>                               <C>          <C>          <C>          <C>          <C>          <C>
$91,927.........................        4.3%         5.7%         6.8%         7.9%         9.0%        12.6%
</TABLE>
 
    The pre-tax yields to maturity set forth in the preceding tables were
calculated by determining the monthly discount rates (whether positive or
negative) which, when applied to the assumed streams of cash flows to be paid on
the Class X and Class IP Certificates, would cause the discounted present values
of such assumed streams of cash flows to equal the assumed purchase price,
including accrued interest, where applicable. These monthly discount rates were
converted to corporate bond equivalent rates, which are higher than the monthly
discount rates because they are based on semiannual compounding. These yields to
maturity do not take into account the different interest rates at which
investors may be able to reinvest funds received by them as distributions on the
Class X or Class IP Certificates and thus do not reflect the return on any
investment in the Class X or Class IP Certificates when any reinvestment rates
other than the discount rates are considered.
 
    There are no historical prepayment data available for the Mortgage Pool, and
comparable data are not available because the Mortgage Loans do not constitute a
representative sample of mortgage loans generally. In addition, historical data
available with respect to mortgage loans underlying mortgage pass-through
certificates issued by the Government National Mortgage Association ("GNMA"),
FNMA and FHLMC may not be comparable to prepayments expected to be experienced
by the Mortgage Pool because the Mortgage Loans may have characteristics which
differ from the mortgage loans underlying certificates issued by GNMA, FNMA and
FHLMC.
 
    The Company makes no representation that the Mortgage Loans will prepay in
the manner or at any of the rates assumed above. Each investor must make its own
decision as to the appropriate prepayment assumptions to be used in deciding
whether or not to purchase any of the Certificates. Since the rate of principal
payments (including prepayments) with respect to, and repurchases of, the
Mortgage Loans will significantly affect the yields to maturity on the Offered
Certificates, prospective investors are urged to consult their investment
advisors as to both the anticipated rate of future principal payments (including
prepayments) on the Mortgage Loans and the suitability of the Certificates to
their investment objectives.
 
YIELD CONSIDERATIONS WITH RESPECT TO THE SENIOR SUBORDINATE CERTIFICATES
 
    The tables beginning on page S-85 have been prepared using the Modeling
Assumptions, except that it has been assumed that (i) defaults occur monthly on
the last day of the previous month at rates which in the aggregate are equal to
the following percentages of the aggregate principal balance of the Mortgage
Loans in the applicable Loan Group as of the Cut-Off Date for the number of
months indicated (and none thereafter); (ii) the scheduled monthly payments for
each Mortgage Loan in the applicable Loan Group are computed based upon its
unpaid principal balance after giving effect to any default; (iii) certain
delinquency experience levels specified in the Pooling Agreement for the
determination of the Group IA and Group IIA Prepayment Percentages, as
applicable, and the Group I and Group II Subordinate Prepayment Percentages, as
applicable, are not exceeded; and (iv) prepayments are calculated as assumed
above but before giving effect to any such defaults (unless such defaults would
reduce the aggregate principal balance of the Mortgage Loans in the applicable
Loan Group below the aggregate amount of
 
                                      S-83
<PAGE>
such assumed prepayments, in which case prepayments are limited to the
outstanding principal balance of such Mortgage Loans after such defaults).
 
<TABLE>
<CAPTION>
                   PRINCIPAL BALANCE OF DEFAULTED  PRINCIPAL BALANCE OF DEFAULTED
                   MORTGAGE LOANS IN LOAN GROUP I  MORTGAGE LOANS IN LOAN GROUP II
                       AS A PERCENTAGE OF THE          AS A PERCENTAGE OF THE
                   AGGREGATE PRINCIPAL BALANCE OF  AGGREGATE PRINCIPAL BALANCE OF
NUMBER OF MONTHS                THE                              THE
  COMMENCING IN    MORTGAGE LOANS IN LOAN GROUP I  MORTGAGE LOANS IN LOAN GROUP II
   APRIL 1998          AS OF THE CUT-OFF DATE          AS OF THE CUT-OFF DATE
- -----------------  ------------------------------  -------------------------------
<S>                <C>                             <C>
      N.A.                      0.00%                           0.00%
       24                       0.35%                           0.50%
       24                       0.75%                           1.25%
       24                       1.50%                           4.00%
</TABLE>
 
    For example, if defaulted Mortgage Loans in Loan Group I total 0.35% of the
aggregate principal balance of the Mortgage Loans in Loan Group I as of the
Cut-Off Date as assumed for purposes of the following tables (approximately
$531,933, which is 0.35% of $151,981,114), and such defaults occur at an amount
per month equal to approximately $22,163 (1/24th of $531,933) in each month of
the 24-month period commencing in April 1998, the effect on the pre-tax yield to
maturity of the Senior Subordinate Certificates from such aggregate defaults on
the Mortgage Loans over such 24-month period would be as shown in the tables
below.
 
    In addition, it was assumed that (i) realized losses on liquidation of the
Mortgage Loans occur at a rate of 20% and 30% or, in the case of the Class
IIB-1, Class IIB-2 and Class IIB-3 Certificates, 20% and 40%, of the outstanding
principal balance of such defaulted Mortgage Loans at the time of default as
indicated in the table (referred to as a "Loss Severity Percentage") in the
month in which the Mortgage Loans first default, (ii) there are no Special
Hazard Losses, Fraud Losses or Bankruptcy Losses, (iii) the Senior Subordinate
Certificates are purchased at the assumed purchase prices equal to the indicated
percentages of the Class IB-1, Class IB-2, Class IB-3, Class IIB-1, Class IIB-2,
or Class IIB-3 Principal Balance, as applicable, plus accrued interest from the
Cut-Off Date and (iv) all scheduled payments on Mortgage Loans are advanced by
the Master Servicer whether or not received from the related Mortgagors.
 
    The rate of distributions in reduction of the Class Principal Balance of any
Class of Senior Subordinate Certificates will be related to the actual
amortization schedule of the Mortgage Loans; accordingly, the interest
distributions and distributions in reduction of the Class Principal Balances of
the Senior Subordinate Certificates may result in yields to maturity which
differ from those reflected below.
 
    The Mortgage Loans will not have the characteristics assumed, and it is
unlikely that they will prepay at any of the constant rates specified. The
assumed percentages of the Basic Prepayment Assumption, the principal balance of
the defaulted Mortgage Loans and the loss severities on the Mortgage Loans shown
in the tables below are for illustrative purposes only and the Company makes no
representations with respect to the reasonableness of such assumptions or that
the actual rates of prepayment and liquidation and loss severity experience of
the Mortgage Loans will in any way correspond to any of the assumptions made
herein. In addition, it is unlikely that liquidations will occur in the month of
default, and the timing of such
 
                                      S-84
<PAGE>
liquidations may cause the pre-tax yield to maturity of the Senior Subordinate
Certificates to differ from those shown below.
 
            PRE-TAX YIELD TO MATURITY OF THE CLASS IB-1 CERTIFICATES
           AT AN ASSUMED PURCHASE PRICE OF 97.250% OF THE CLASS IB-1
         PRINCIPAL BALANCE PLUS ACCRUED INTEREST FROM THE CUT-OFF DATE
 
<TABLE>
<CAPTION>
   DEFAULTED GROUP I
 LOANS EXPRESSED AS A
   PERCENTAGE OF THE
  AGGREGATE PRINCIPAL
BALANCE OF THE GROUP I
LOANS AS OF THE CUT-OFF
DATE OVER THE 24-MONTH                  PERCENTAGE OF THE BASIC PREPAYMENT ASSUMPTION                       LOSS
 PERIOD COMMENCING IN    ----------------------------------------------------------------------------     SEVERITY
      APRIL 1998             0%          105%         175%         240%         300%         500%        PERCENTAGE
- -----------------------  -----------  -----------  -----------  -----------  -----------  -----------  ---------------
<S>                      <C>          <C>          <C>          <C>          <C>          <C>          <C>
              0               7.50%        7.52%        7.52%        7.53%        7.54%        7.56%             0%
           0.35%              7.52%        7.52%        7.53%        7.53%        7.54%        7.56%            20%
           0.35%              7.53%        7.52%        7.53%        7.53%        7.54%        7.56%            30%
           0.75%              7.54%        7.52%        7.53%        7.53%        7.54%        7.56%            20%
           0.75%              7.55%        7.53%        7.53%        7.54%        7.54%        7.56%            30%
           1.50%              7.55%        7.54%        7.54%        7.54%        7.54%        7.56%            20%
           1.50%              7.56%        7.55%        7.55%        7.55%        7.55%        7.56%            30%
</TABLE>
 
            PRE-TAX YIELD TO MATURITY OF THE CLASS IB-2 CERTIFICATES
           AT AN ASSUMED PURCHASE PRICE OF 96.500% OF THE CLASS IB-2
         PRINCIPAL BALANCE PLUS ACCRUED INTEREST FROM THE CUT-OFF DATE
 
<TABLE>
<CAPTION>
   DEFAULTED GROUP I
 LOANS EXPRESSED AS A
   PERCENTAGE OF THE
  AGGREGATE PRINCIPAL
BALANCE OF THE GROUP I
LOANS AS OF THE CUT-OFF
DATE OVER THE 24-MONTH                  PERCENTAGE OF THE BASIC PREPAYMENT ASSUMPTION                       LOSS
 PERIOD COMMENCING IN    ----------------------------------------------------------------------------     SEVERITY
      APRIL 1998             0%          105%         175%         240%         300%         500%        PERCENTAGE
- -----------------------  -----------  -----------  -----------  -----------  -----------  -----------  ---------------
<S>                      <C>          <C>          <C>          <C>          <C>          <C>          <C>
              0               7.64%        7.65%        7.67%        7.68%        7.69%        7.71%             0%
           0.35%              7.64%        7.66%        7.67%        7.68%        7.69%        7.71%            20%
           0.35%              7.62%        7.66%        7.67%        7.68%        7.69%        7.71%            30%
           0.75%              7.61%        7.67%        7.67%        7.68%        7.69%        7.72%            20%
           0.75%              7.59%        7.68%        7.68%        7.68%        7.69%        7.72%            30%
           1.50%              7.58%        7.65%        7.68%        7.69%        7.69%        7.72%            20%
           1.50%              7.55%        7.61%        7.65%        7.69%        7.70%        7.72%            30%
</TABLE>
 
                                      S-85
<PAGE>
            PRE-TAX YIELD TO MATURITY OF THE CLASS IB-3 CERTIFICATES
           AT AN ASSUMED PURCHASE PRICE OF 95.500% OF THE CLASS IB-3
         PRINCIPAL BALANCE PLUS ACCRUED INTEREST FROM THE CUT-OFF DATE
 
<TABLE>
<CAPTION>
   DEFAULTED GROUP I
 LOANS EXPRESSED AS A
   PERCENTAGE OF THE
  AGGREGATE PRINCIPAL
BALANCE OF THE GROUP I
LOANS AS OF THE CUT-OFF
DATE OVER THE 24-MONTH                  PERCENTAGE OF THE BASIC PREPAYMENT ASSUMPTION                       LOSS
 PERIOD COMMENCING IN    ----------------------------------------------------------------------------     SEVERITY
      APRIL 1998             0%          105%         175%         240%         300%         500%        PERCENTAGE
- -----------------------  -----------  -----------  -----------  -----------  -----------  -----------  ---------------
<S>                      <C>          <C>          <C>          <C>          <C>          <C>          <C>
              0               7.82%        7.84%        7.86%        7.87%        7.88%        7.92%             0%
           0.35%              7.82%        7.85%        7.86%        7.87%        7.88%        7.92%            20%
           0.35%              7.77%        7.85%        7.86%        7.88%        7.89%        7.92%            30%
           0.75%              7.76%        7.86%        7.87%        7.88%        7.89%        7.92%            20%
           0.75%              7.73%        7.82%        7.87%        7.88%        7.89%        7.92%            30%
           1.50%              7.71%        7.80%        7.85%        7.89%        7.89%        7.92%            20%
           1.50%              7.67%        7.75%        7.80%        7.84%        7.87%        7.93%            30%
</TABLE>
 
           PRE-TAX YIELD TO MATURITY OF THE CLASS IIB-1 CERTIFICATES
           AT AN ASSUMED PURCHASE PRICE OF 97.250% OF THE CLASS IIB-1
         PRINCIPAL BALANCE PLUS ACCRUED INTEREST FROM THE CUT-OFF DATE
 
<TABLE>
<CAPTION>
  DEFAULTED GROUP II
 LOANS EXPRESSED AS A
   PERCENTAGE OF THE
  AGGREGATE PRINCIPAL
BALANCE OF THE GROUP II
LOANS AS OF THE CUT-OFF
DATE OVER THE 24-MONTH                  PERCENTAGE OF THE BASIC PREPAYMENT ASSUMPTION                       LOSS
 PERIOD COMMENCING IN    ----------------------------------------------------------------------------     SEVERITY
      APRIL 1998             0%          100%         175%         250%         350%         500%        PERCENTAGE
- -----------------------  -----------  -----------  -----------  -----------  -----------  -----------  ---------------
<S>                      <C>          <C>          <C>          <C>          <C>          <C>          <C>
              0               7.86%        7.90%        7.92%        7.94%        7.97%        7.99%             0%
           0.50%              7.87%        7.90%        7.92%        7.94%        7.97%        7.99%            20%
           0.50%              7.88%        7.90%        7.93%        7.95%        7.97%        7.99%            40%
           1.25%              7.88%        7.90%        7.93%        7.95%        7.97%        8.00%            20%
           1.25%              7.89%        7.91%        7.93%        7.95%        7.97%        8.00%            40%
           4.00%              7.89%        7.92%        7.94%        7.95%        7.97%        8.00%            20%
           4.00%              7.88%        7.92%        7.94%        7.94%        7.96%        7.99%            40%
</TABLE>
 
                                      S-86
<PAGE>
           PRE-TAX YIELD TO MATURITY OF THE CLASS IIB-2 CERTIFICATES
           AT AN ASSUMED PURCHASE PRICE OF 96.250% OF THE CLASS IIB-2
         PRINCIPAL BALANCE PLUS ACCRUED INTEREST FROM THE CUT-OFF DATE
 
<TABLE>
<CAPTION>
  DEFAULTED GROUP II
 LOANS EXPRESSED AS A
   PERCENTAGE OF THE
  AGGREGATE PRINCIPAL
BALANCE OF THE GROUP II
LOANS AS OF THE CUT-OFF
DATE OVER THE 24-MONTH                  PERCENTAGE OF THE BASIC PREPAYMENT ASSUMPTION                       LOSS
 PERIOD COMMENCING IN    ----------------------------------------------------------------------------     SEVERITY
      APRIL 1998             0%          100%         175%         250%         350%         500%        PERCENTAGE
- -----------------------  -----------  -----------  -----------  -----------  -----------  -----------  ---------------
<S>                      <C>          <C>          <C>          <C>          <C>          <C>          <C>
              0               7.97%        8.03%        8.06%        8.09%        8.13%        8.17%             0%
           0.50%              7.96%        8.03%        8.06%        8.09%        8.13%        8.17%            20%
           0.50%              7.96%        8.03%        8.07%        8.09%        8.13%        8.17%            40%
           1.25%              7.96%        8.03%        8.07%        8.10%        8.13%        8.17%            20%
           1.25%              7.94%        8.03%        8.07%        8.10%        8.13%        8.17%            40%
           4.00%              7.94%        8.03%        8.07%        8.10%        8.13%        8.17%            20%
           4.00%              7.23%        7.17%        7.10%        7.03%        6.98%        6.93%            40%
</TABLE>
 
           PRE-TAX YIELD TO MATURITY OF THE CLASS IIB-3 CERTIFICATES
           AT AN ASSUMED PURCHASE PRICE OF 95.750% OF THE CLASS IIB-3
         PRINCIPAL BALANCE PLUS ACCRUED INTEREST FROM THE CUT-OFF DATE
 
<TABLE>
<CAPTION>
  DEFAULTED GROUP II
 LOANS EXPRESSED AS A
   PERCENTAGE OF THE
  AGGREGATE PRINCIPAL
BALANCE OF THE GROUP II
LOANS AS OF THE CUT-OFF
DATE OVER THE 24-MONTH                  PERCENTAGE OF THE BASIC PREPAYMENT ASSUMPTION                       LOSS
 PERIOD COMMENCING IN    ----------------------------------------------------------------------------     SEVERITY
      APRIL 1998             0%          100%         175%         250%         350%         500%        PERCENTAGE
- -----------------------  -----------  -----------  -----------  -----------  -----------  -----------  ---------------
<S>                      <C>          <C>          <C>          <C>          <C>          <C>          <C>
              0               8.02%        8.09%        8.13%        8.17%        8.21%        8.25%             0%
           0.50%              8.01%        8.09%        8.13%        8.17%        8.21%        8.25%            20%
           0.50%              8.00%        8.09%        8.14%        8.17%        8.21%        8.25%            40%
           1.25%              7.99%        8.09%        8.14%        8.17%        8.21%        8.25%            20%
           1.25%              7.98%        8.07%        8.13%        8.16%        8.21%        8.25%            40%
           4.00%              7.97%        8.03%        8.10%        8.16%        8.20%        8.25%            20%
           4.00%            (78.25%)     (78.25%)     (78.25%)     (78.19%)     (78.21%)     (78.14%)           40%
</TABLE>
 
    The pre-tax yields to maturity set forth in the preceding tables were
calculated by determining the monthly discount rates which, when applied to the
assumed streams of cash flows to be paid on each Class of Senior Subordinate
Certificates, would cause the discounted present value of such assumed stream of
cash flows to equal the assumed offering prices (including accrued interest) of
each Class of the Senior Subordinate Certificates set forth above. In all cases
monthly rates are then converted to the corporate bond equivalent yields shown
above. Implicit in the use of any discounted present value or internal rate of
return calculation such as these is the assumption that intermediate cash flows
are invested at the discount rate or internal rate of return. Thus these
calculations do not take into account the different interest rates at which
investors may be able to reinvest funds received by them as distributed on the
Senior Subordinate Certificates. Consequently, these yields to maturity do not
purport to reflect the return on any investment in the Senior Subordinate
Certificates when such reinvestment rates are considered.
 
    The characteristics of the Mortgage Loans will not correspond exactly to
those assumed in preparing the tables above. The yield to maturity of each Class
of the Senior Subordinate Certificates therefore will differ even if all the
Mortgage Loans in the related Loan Group prepay monthly at the related assumed
prepayment rate. In addition, it is not likely that the Mortgage Loans will
prepay at the same percentage of
 
                                      S-87
<PAGE>
the Basic Prepayment Assumption, and the timing of changes in the rate of
prepayments may affect significantly the yield to maturity received by a holder
of a Class of Senior Subordinate Certificates. There are no historical
prepayment data available for the Mortgage Pool, and comparable data are not
available because the Mortgage Loans do not constitute a representative sample
of mortgage loans generally. In addition, historical data available with respect
to mortgage loans underlying mortgage pass-through certificates issued by GNMA,
FNMA or FHLMC may not be comparable to prepayments expected to be experienced by
the Mortgage Pool, because the Mortgage Loans may have characteristics which
differ from mortgage loans underlying certificates issued by GNMA, FNMA and
FHLMC.
 
    The Company makes no representation that the Mortgage Loans will prepay in
the manner or at any of the rates assumed above. Each investor must make its own
decision as to the appropriate prepayment assumptions to be used in deciding
whether or not to purchase any of the Senior Subordinate Certificates. Since the
rate of principal payments (including Principal Prepayments) with respect to,
and repurchases of, the Mortgage Loans in the applicable Loan Group will
significantly affect the yield to maturity on each Class of the Senior
Subordinate Certificates, prospective investors are urged to consult their
investment advisors as to both the anticipated rate of future principal payments
(including Principal Prepayments) on the Mortgage Loans in the applicable Loan
Group and the suitability of the Senior Subordinate Certificates to their
investment objectives.
 
ADDITIONAL YIELD CONSIDERATIONS APPLICABLE SOLELY TO THE CLASS R CERTIFICATES
 
    The Class R Certificateholders' after-tax rate of return on their
Certificates will reflect their pre-tax rate of return, reduced by the taxes
required to be paid with respect to such Certificates. Holders of Class R
Certificates may have tax liabilities with respect to their Certificates during
the early years of the REMIC's term that substantially exceed any distributions
payable thereon during any such period. In addition, holders of Class R
Certificates may have tax liabilities with respect to their Certificates the
present value of which substantially exceeds the present value of distributions
payable thereon and of any tax benefits that may arise with respect thereto.
Accordingly, the after-tax rate of return on the Class R Certificates may be
negative or may otherwise be significantly adversely affected. The timing and
amount of taxable income attributable to the Class R Certificates will depend
on, among other things, the timing and amounts of prepayments and losses
experienced with respect to the Mortgage Pool.
 
    The Class R Certificateholders should consult their own tax advisors as to
the effect of taxes and the receipt of any payments made to such holders in
connection with the purchase of the Class R Certificates on after-tax rates of
return on the Class R Certificates. See "Certain Federal Income Tax
Consequences" herein and in the Prospectus.
 
ADDITIONAL INFORMATION
 
    The Company intends to file with the Securities and Exchange Commission
certain additional yield tables and other computational materials with respect
to one or more Classes of the Offered Certificates on a Current Report on Form
8-K. Such tables and materials were prepared by the Underwriter at the request
of certain prospective investors, based on assumptions provided by, and
satisfying the special requirements of, such prospective investors. Such tables
and materials are preliminary in nature, and the information contained therein
is subject to, and superseded by, the information in this Supplement.
 
                              CREDIT ENHANCEMENTS
 
SUBORDINATION
 
    The holders of the Senior Certificates of a Certificate Group are entitled
to receive distributions of interest (except, with respect to the Group I
Certificates, the Class IP Certificates and the PO Component of the Class IIA-1
Certificates, which are not entitled to interest) and principal (except, with
respect to the Group I Certificates, the Class IX Certificates and, with respect
to the Group II Certificates, Class IIX Certificates, which are not entitled to
principal) before distributions of interest or principal to the holders
 
                                      S-88
<PAGE>
of the Class B Certificates of the related Certificate Group. No Class B
Certificates of a Certificate Group will receive distributions of interest or
principal on any Distribution Date until the Class or Classes in the related
Certificate Group senior to such Class have received all distributions of
interest and principal due on or before such Distribution Date. See "Description
of the Certificates -- Priority of Distributions" herein.
 
    Losses on Mortgage Loans in a Loan Group will be allocated, in each case
until the applicable Class Principal Balances have been reduced to zero, first,
to the Junior Subordinate Certificates in the related Certificate Group; second,
to the Class IB-3 or Class IIB-3 Certificates, as applicable; third, to the
Class IB-2 or Class IIB-2 Certificates, as applicable; fourth, to the Class IB-1
or Class IIB-1 Certificates, as applicable; and fifth, to the outstanding
Classes of Senior Certificates in the related Certificate Group by Pro Rata
Allocation; PROVIDED, HOWEVER, that only a certain specified amount of Fraud
Losses and Bankruptcy Losses in a Loan Group will be allocated solely to the
Class B Certificates in the related Certificate Group and only a certain
specified amount of Special Hazard Losses in a Loan Group will be allocated
solely to the Class B Certificates in both Certificate Groups, following which
such losses will be allocated among all outstanding Classes of Certificates in
the related Certificate Group by Pro Rata Allocation; PROVIDED, FURTHER, that in
the event any loss is incurred with respect to a Class IP Mortgage Loan or a PO
Component Mortgage Loan, the applicable Class IP Fraction or PO Component
Fraction of such loss will first be allocated to such Class IP Mortgage Loan or
PO Component Mortgage Loan and the remainder of such loss will be allocated as
described above.
 
SHIFTING OF INTERESTS
 
    The Senior Certificates of a Certificate Group entitled to principal, other
than the Lockout Certificates of such Certificate Group, will receive 100% of
Principal Prepayments received with respect to the Mortgage Loans in the related
Loan Group until the fifth anniversary of the first Distribution Date. During
the next four years, such Senior Certificates, other than the Lockout
Certificates of such Certificate Group, will receive a disproportionately large,
but decreasing, share of Principal Prepayments received with respect to the
Mortgage Loans in the related Loan Group. This will result in an acceleration of
the amortization of such Senior Certificates, other than the Lockout
Certificates, subject to the priorities described in "Description of the
Certificates -- Distributions of Principal" herein, enhancing the likelihood
that holders of such Classes of Certificates will be paid the full amount of
principal to which they are entitled.
 
    See "Description of the Certificates -- Distributions of Principal" herein.
 
    Although the Lockout Certificates are Senior Certificates, the Class IA-3
and Class IIA-4 Certificates will generally not be entitled to receive any
distributions of Principal Prepayments until May 2002. Therefore, the Class IA-3
and Class IIA-4 Certificates will not be entitled to receive the
disproportionate allocation of Principal Prepayments in the related Loan Group
that the other Senior Certificates in the same Certificate Group are entitled to
receive. See "Description of the Certificates -- Distributions of Principal".
 
                    CERTAIN FEDERAL INCOME TAX CONSEQUENCES
 
    For federal income tax purposes, the Company will cause an election to be
made to treat the Trust as a REMIC. The certificates issued by the Trust, other
than the Class R Certificates, will be designated as REMIC regular interests. As
REMIC regular interests, such certificates or components will generally be
treated as debt for federal income tax purposes. Certificateholders will be
required to include in income all interest and original issue discount ("OID")
on such Certificates in accordance with the accrual method of accounting
regardless of the Certificateholders' usual methods of accounting. For federal
income tax purposes the Class R Certificates will be the residual interest in
the Trust.
 
    The Class IA-1, Class IA-2, Class IA-7, Class IX-1, Class IX-2, Class IP,
Class IIA-5 and Class IIX Certificates will, and the Class IA-5, Class IA-6,
Class IB-1, Class IB-2, Class IB-3, Class IIA-3,
 
                                      S-89
<PAGE>
Class IIA-6, Class IIA-7, Class IIB-1, Class IIB-2 and Class IIB-3 Certificates
may, be treated as having been issued with OID for federal income tax purposes.
The prepayment assumption that will be used in determining the rate of accrual
of market discount and premium, if any, for federal income tax purposes is 240%
of the Basic Prepayment Assumption for Loan Group I and 250% of the Basic
Prepayment Assumption for Loan Group II as described herein under "Yield and
Prepayment Considerations". No representation is made that the Mortgage Loans
will prepay at any given percentage of the Basic Prepayment Assumption.
 
    In certain circumstances OID Regulations (as defined in "Certain Federal
Income Tax Consequences" in the Prospectus) permit the holder of a debt
instrument to recognize original issue discount under a method that differs from
that used by the issuer. Accordingly, it is possible that the holder of a
Certificate may be able to select a method for recognizing original issue
discount that differs from that used by the Company in preparing reports to the
Certificateholders and the IRS.
 
    If actual prepayments differ sufficiently from the prepayment assumption,
the calculation of OID for certain Classes of Offered Certificates might produce
a negative number for certain accrual periods. In such event, Certificateholders
will not be entitled to a deduction for such amount, but will be required to
carry such amount forward as an offset to OID, if any, accruing in future
accrual periods.
 
    Certain Classes of Certificates may be treated for federal income tax
purposes as having been issued at a premium. Whether any holder of a Certificate
will be treated as holding a Certificate with amortizable bond premium will
depend on such Certificateholder's purchase price and the distributions
remaining to be made on such Certificate at the time of its acquisition by such
Certificateholder. Holders of such Classes of Certificates should consult their
own tax advisors regarding the possibility of making an election to amortize any
such premium. See "Certain Federal Income Tax Consequences -- Taxation of Owners
of REMIC Regular Certificates -- Original Issue Discount" and "-- Market
Discount and Premium" in the Prospectus.
 
    The Offered Certificates will generally be treated as "qualifying real
property loans" for mutual savings banks and domestic building and loan
associations, "loans secured by an interest in real property" for domestic
building and loan associations, and "real estate assets" for real estate
investment trusts ("REITs") in the same proportion that the assets in the REMICs
would be so treated. In addition, interest on the Offered Certificates will
generally be treated as "interest on obligations secured by mortgages on real
property" for REITs to the extent that such Offered Certificates are treated as
"real estate assets". Recently enacted legislation repealed the provisions of
Section 593(d) of the Internal Revenue Code allowing the reserve method of
accounting for bad debts, effective for taxable years beginning after December
31, 1995. See "Certain Federal Income Tax Consequences" in the Prospectus.
 
SPECIAL TAX CONSIDERATIONS APPLICABLE TO THE RESIDUAL CERTIFICATES
 
    The Internal Revenue Service has issued regulations under the provisions of
the Code related to REMICs (the "REMIC Regulations") that significantly affect
holders of the Class R Certificates. The REMIC Regulations impose restrictions
on the transfer or acquisition of certain residual interests, including the
Class R Certificates. In addition, the REMIC Regulations contain restrictions
that apply to the transfer of "noneconomic" residual interests to United States
persons. Pursuant to the Pooling Agreement, the Class R Certificates may not be
transferred to non-United States persons.
 
    The Small Business Job Protection Act of 1996 has eliminated the special
rule permitting Section 593 institutions ("thrift institutions") to use net
operating losses and other allowable deductions to offset their excess inclusion
income from REMIC residual certificates that have "significant value" within the
meaning of the REMIC Regulations, effective for taxable years beginning after
December 31, 1995, except with respect to residual certificates continuously
held by a thrift institution since November 1, 1995.
 
    In addition, the Small Business Job Protection Act of 1996 provides three
rules for determining the effect on excess inclusions on the alternative minimum
taxable income of a residual holder. First, alternative minimum taxable income
for such residual holder is determined without regard to the special
 
                                      S-90
<PAGE>
rule that taxable income cannot be less than excess inclusions. Second, a
residual holder's alternative minimum taxable income for a tax year cannot be
less than excess inclusions for the year. Third, the amount of any alternative
minimum tax net operating loss deductions must be computed without regard to any
excess inclusions. These rules are effective for tax years beginning after
December 31, 1986, unless a residual holder elects to have such rules apply only
to tax years beginning after August 20, 1996.
 
    The REMIC Regulations provide that a transfer to a United States person of
"noneconomic" residual interests will be disregarded for all federal income tax
purposes, and that the purported transferor of "noneconomic" residual interests
will continue to remain liable for any taxes due with respect to the income on
such residual interests, unless "no significant purpose of the transfer was to
impede the assessment or collection of tax". Based on the REMIC Regulations, the
Class R Certificates may constitute noneconomic residual interests during some
or all of their terms for purposes of the REMIC Regulations and, accordingly,
unless no significant purpose of a transfer is to impede the assessment or
collection of tax, transfers of the Class R Certificates may be disregarded and
purported transferors may remain liable for any taxes due with respect to the
income on the Class R Certificates. All transfers of the Class R Certificates
will be subject to certain restrictions under the terms of the Pooling Agreement
that are intended to reduce the possibility of any such transfer being
disregarded to the extent that the Class R Certificates constitute noneconomic
residual interests. See "Certain Federal Income Tax Consequences -- Taxation of
Owners of REMIC Residual Certificates -- Noneconomic REMIC Residual
Certificates" in the Prospectus.
 
    The Class R Certificateholders may be required to report an amount of
taxable income with respect to the earlier accrual periods of the REMIC's term
that significantly exceeds the amount of cash distributions received by such
Class R Certificateholders from the REMIC with respect to such periods.
Consequently, the Class R Certificateholders should have other sources of funds
sufficient to pay any federal income taxes due in the earlier years of the REMIC
as a result of their ownership of such Class R Certificates. In addition, the
required inclusion of this amount of taxable income during the REMIC's earlier
accrual periods and the deferral of corresponding tax losses or deductions until
later accrual periods or until the ultimate sale or disposition of a Class R
Certificate (or possibly later under the "wash sale" rules of Section 1091 of
the Code) may cause the Class R Certificateholders' after-tax rate of return to
be zero or negative even if the Class R Certificateholders' pre-tax rate of
return is positive. That is, on a present value basis, the Class R
Certificateholders' resulting tax liabilities could substantially exceed the sum
of any tax benefits and the amount of any cash distributions on such Class R
Certificates over their life.
 
    As discussed above, the rules for accrual of original issue discount with
respect to certain Classes of Certificates are subject to significant complexity
and uncertainty. Because original issue discount on the Certificates will be
deducted by the related REMIC in determining its taxable income, any changes
required by the Internal Revenue Service in the application of those rules to
the Certificates may significantly affect the timing of original issue discount
deductions to the related REMIC and therefore the amount of the related REMIC's
taxable income allocable to holders of the Class R Certificates.
 
    Purchasers of the Class R Certificates are strongly advised to consult their
own tax advisors as to the economic and tax consequences of investment in such
Certificates.
 
    For further information regarding the federal income tax consequences of
investing in the Class R Certificates, see "Certain Yield and Prepayment
Considerations -- Additional Yield Considerations Applicable Solely to the Class
R Certificates" herein and "Certain Federal Income Tax Consequences -- Taxation
of Owners of REMIC Residual Certificates" in the Prospectus.
 
    An individual, trust or estate that holds (whether directly or indirectly
through certain pass-through entities) a Class R Certificate may have
significant additional gross income with respect to, but may be subject to
limitations on the deductibility of, servicing and trustee's fees and other
administrative expenses properly allocable to the related REMIC in computing
such Certificateholder's regular tax liability and will not be able to deduct
such fees or expenses to any extent in computing such Certificateholder's
alternative minimum tax liability. Such expenses will be allocated for federal
income tax information reporting
 
                                      S-91
<PAGE>
purposes entirely to the Class R Certificates. However, it is possible that the
IRS may require all or some portion of such fees and expenses to be allocated to
the Class R Certificates. See "Certain Federal Income Tax Consequences --
Pass-Through of Servicing Fees" and "-- Taxation of Owners of REMIC Residual
Certificates" in the Prospectus.
 
    The Company will be designated as the "tax matters persons" with respect to
the Trust as defined in the REMIC Regulations (defined below), and in connection
therewith will be required to hold not less than 0.01% of the Class R
Certificates.
 
    For further information regarding the federal income tax consequences of
investing in the Certificates, see "Certain Federal Income Tax Consequences" in
the Prospectus.
 
                        CERTAIN LEGAL INVESTMENT ASPECTS
 
    As of the date of their issuance, the Offered Certificates, other than the
Class IB-2, Class IB-3, Class IIB-2 and Class IIB-3 Certificates, will
constitute "mortgage related securities" for purposes of the Secondary Mortgage
Market Enhancement Act of 1984 ("SMMEA"), and as such will be legal investments
for persons, trusts, corporations, partnerships, associations, business trusts
and business entities (including depository institutions, life insurance
companies, and pension funds) created pursuant to or existing under the laws of
the United States or of any state whose authorized investments are subject to
state regulation to the same extent that, under applicable law, obligations
issued by or guaranteed as to principal and interest by the United States or any
agency or instrumentality thereof constitute legal investments for such
entities. Under SMMEA, if a state enacted legislation prior to October 4, 1991
specifically limiting the legal investment authority of any of such entities
with respect to "mortgage related securities", the Offered Certificates, other
than the Class IB-2, Class IB-3, Class IIB-2 and Class IIB-3 Certificates, will
constitute legal investments for entities subject to such legislation only to
the extent provided therein. Certain states have enacted such legislation.
Investors should consult their own legal advisors in determining whether and to
what extent the Offered Certificates, constitute legal investments for such
investors.
 
    SMMEA also amended the legal investment authority of federally-chartered
depository institutions as follows: federal savings and loan associations and
federal savings banks may invest in, sell or otherwise deal with the Offered
Certificates, other than the Class IB-2, Class IB-3, Class IIB-2 and Class IIB-3
Certificates, without limitation as to the percentage of their assets
represented thereby, federal credit unions may invest in the Offered
Certificates, other than the Class IB-2, Class IB-3, Class IIB-2 and Class IIB-3
Certificates, and national banks may purchase the Offered Certificates, other
than the Class IB-2, Class IB-3, Class IIB-2 and Class IIB-3 Certificates, for
their own accounts without regard to the limitations generally applicable to
investment securities set forth in 12 U.S.C. 24 (Seventh), in each case subject
to such regulations as the applicable federal regulatory authority may
prescribe.
 
    Institutions whose investment activities are subject to review by certain
regulatory authorities hereafter may be or may become subject to restrictions on
investment in the Offered Certificates, and such restrictions may be
retroactively imposed. The Federal Financial Institutions Examination Council,
the Federal Deposit Insurance Corporation, the Office of the Comptroller of the
Currency, the Board of Governors of the Federal Reserve System, the Office of
Thrift Supervision and the National Credit Union Administration have adopted
guidelines, and have proposed policies, regarding the suitability of investments
in various types of derivative mortgage-backed securities, including securities
such as the Offered Certificates. In addition, several states have adopted or
are considering regulations that would prohibit regulated institutions subject
to their jurisdiction from holding mortgage-backed securities such as the
Offered Certificates, including such securities previously purchased. Investors
should consult their own legal advisors in determining whether and to what
extent the Offered Certificates constitute legal investments for such investors.
 
                                      S-92
<PAGE>
    There may be other restrictions on the ability of certain investors,
including depository institutions, either to purchase the Offered Certificates
or to purchase the Offered Certificates representing more than a specified
percentage of the investor's assets. Investors should consult their own legal
advisors in determining whether and to what extent the Offered Certificates
constitute legal investments for such investors.
 
                              ERISA CONSIDERATIONS
 
    Any fiduciary of an employee benefit plan or other benefit plan or
arrangement which is subject to the Employee Retirement Income Security Act of
1974, as amended ("ERISA"), or Section 4975 of the Internal Revenue Code of
1986, as amended (the "Code") (each, a "Plan"), or other person that proposes to
use "plan assets" of any Plan to acquire any Offered Certificates should consult
with its counsel with respect to the potential consequences under ERISA and
Section 4975 of the Code of the acquisition and ownership of such Certificates
by, on behalf of or with "plan assets" of any Plan. See "ERISA Considerations"
in the Prospectus.
 
UNDERWRITER'S PTE
 
    Donaldson, Lufkin & Jenrette Securities Corporation (the "Underwriter") is
the recipient of a final prohibited transaction exemption (the "Underwriter's
PTE") which may afford protection from violations under Sections 406 and 407 of
ERISA and Section 4975 of the Code for Plans that acquire Offered Certificates
(other than the Senior Subordinate Certificates). It is not clear whether
exemptive relief is available under the Underwriter's PTE for Plans that acquire
the Residual Certificates. Plans (or persons using "plan assets" of any Plan)
that acquire Offered Certificates (other than the Senior Subordinate
Certificates) may be eligible for exemptive relief under the Underwriter's PTE
if:
 
        (a) The Class of such Certificates acquired by the Plan is not
    subordinated to other Classes of Certificates with respect to the right to
    receive payment in the event of defaults or delinquencies on the underlying
    Mortgage Loans;
 
        (b) The Plan is an "accredited investor" (as defined in Rule 501(a)(1)
    of Regulation D under the Securities Act of 1933, as amended (the "Act"));
 
        (c) The acquisition of such Certificates by the Plan is on terms
    (including the price paid for the Certificates) that are at least as
    favorable to the Plan as they would be in an arm's length transaction with
    an unrelated party; and
 
        (d) The sum of all payments made to and retained by the Underwriter in
    connection with the distribution of such Certificates represents not more
    than reasonable compensation for underwriting such Certificates; the sum of
    all payments made to and retained by the Company pursuant to the sale of the
    Mortgage Loans to the Trust represents not more than the fair market value
    of the Mortgage Loans; and the sum of all payments made to and retained by
    the Company or any other servicer represents not more than reasonable
    compensation for their services under the Pooling Agreement and
    reimbursement of their reasonable expenses in connection therewith.
 
    In addition, the Underwriter's PTE will not provide exemptive relief for
certain transactions prohibited by Section 406(b) of ERISA or Section
4975(c)(1)(E) or (F) of the Code that may result from an investment of "plan
assets" of any Plan in such Certificates if:
 
        (e) The Plan's investment in any Class of such Certificates exceeds 25%
    of the outstanding Certificates of that Class at the time of acquisition;
 
        (f) 25% or more of the Plan assets with respect to which the investing
    fiduciary has discretionary authority or renders investment advice are
    invested in certificates evidencing interests in trusts sponsored or
    containing assets sold or serviced by the Company;
 
                                      S-93
<PAGE>
        (g) The Plan is sponsored by the Company, the Underwriter, the Trustee,
    any servicer, the obligor under any credit support mechanism, or any
    mortgagor with respect to Mortgage Loans constituting more than 5% of the
    aggregate unamortized principal balance of the Mortgage Loans on the Closing
    Date (a "Major Obligor") or their affiliates; or
 
        (h) The Plan fiduciary responsible for the decision to invest or any of
    its affiliates is a Major Obligor.
 
    Whether the conditions of the Underwriter's PTE will be satisfied with
respect to Offered Certificates of a particular Class (other than the Senior
Subordinate Certificates, for which the Underwriter's PTE will not afford
exemptive relief) will depend upon the facts and circumstances existing at the
time the Plan acquires (or "plan assets" of the Plan are used to acquire)
Certificates of that Class. Any Plan fiduciary or other person that proposes to
use "plan assets" of any Plan to acquire such Offered Certificates in reliance
upon the Underwriter's PTE should determine whether such acquisition will
satisfy all applicable conditions and consult with its counsel regarding other
factors that may affect the applicability of the Underwriter's PTE.
 
PROHIBITED TRANSACTION CLASS EXEMPTIONS
 
    To qualify for exemption under PTCE 83-1 (see "ERISA Considerations --
Prohibited Transaction Class Exemption 83-1" in the Prospectus), a Certificate
(i) must entitle its holder to more than nominal pass-through payments of both
principal and interest from the Mortgage Loans, (ii) must not be subordinated to
other Classes of Certificates with respect to the right to receive payments in
the event of defaults or delinquencies on the underlying Mortgage Loans and
(iii) must not be issued by a Trust which holds cooperative apartment Mortgage
Loans. See "ERISA Considerations -- Prohibited Transaction Class Exemption 83-1"
in the Prospectus.
 
    Because the Trust will hold cooperative apartment Mortgage Loans, PTCE 83-1
will not afford exemptive relief to Plans (or persons using "plan assets" of any
Plan) that acquire Offered Certificates from the prohibited transaction rules of
ERISA or Section 4975 of the Code. Purchasers using insurance company general
account assets to effect the purchase of the Senior Subordinate Certificates
should consider the availability of exemptive relief under Section III of PTCE
95-60. See "ERISA Considerations -- Prohibited Transaction Class Exemption 83-1"
and "-- Other Exemptions" in the Prospectus.
 
RESTRICTIONS ON SENIOR SUBORDINATE AND RESIDUAL CERTIFICATES
 
    Because the Senior Subordinate Certificates will not qualify for exemptive
relief under the Underwriter's PTE or PTCE 83-1, and because it is not clear
whether the Residual Certificates may qualify for exemptive relief under the
Underwriter's PTE, purchases of such Certificates by, on behalf of or with "plan
assets" of any Plan will not to be registered unless the transferee (i) provides
an opinion of counsel satisfactory to the Trustee and the Company that the
purchase of any such Certificate by, on behalf of or with "plan assets" of such
Plan is permissible under applicable law, will not constitute or result in a
non-exempt prohibited transaction under ERISA or Section 4975 of the Code, and
will not subject the Master Servicer, the Company or the Trustee to any
obligation in addition to those undertaken in the Pooling Agreement or (ii)
represents that it is an insurance company using assets of its general account
to effect such purchase in reliance upon the availability of exemptive relief
under Section III of PTCE 95-60. See "ERISA Considerations" in the Prospectus.
 
                             METHOD OF DISTRIBUTION
 
    Subject to the terms and conditions set forth in the Underwriting Agreement,
the Company has agreed to sell to the Underwriter, and the Underwriter has
agreed to purchase, all of the Offered Certificates, other than the 0.01%
Percentage Interest of the Class R Certificates to be retained by the Company.
The aggregate proceeds (excluding accrued interest) to the Company from the sale
of the
 
                                      S-94
<PAGE>
Offered Certificates, before deducting expenses estimated to be $520,000, will
be approximately 100.910% of the initial aggregate Certificate Principal Balance
of the Offered Certificates. Under the terms and conditions of the Underwriting
Agreement, the Underwriter is committed to take and pay for all of such Offered
Certificates, if any are taken. Distribution of such Offered Certificates will
be made by the Underwriter from time to time in negotiated transactions or
otherwise at varying prices to be determined at the time of sale. The difference
between the purchase price for the Offered Certificates paid to the Company and
the proceeds from the sale of such Certificates realized by the Underwriter will
constitute underwriting discounts and commissions.
 
    The Company has agreed to indemnify the Underwriter against certain civil
liabilities, including liabilities under the Act.
 
                                 LEGAL MATTERS
 
    Certain legal matters will be passed upon for the Company by Thomas G.
Lehmann, General Counsel, Vice President and Secretary of the Company, and by
its special counsel, Orrick, Herrington & Sutcliffe LLP, San Francisco,
California. Brown & Wood LLP, New York, New York, will pass upon certain legal
matters on behalf of the Underwriter.
 
                              CERTIFICATE RATINGS
 
    It is a condition to the issuance of the Offered Certificates that the Class
A Certificates and Class R Certificates each be rated "AAA" by Standard &
Poor's, a division of The McGraw-Hill Companies, Inc. ("S&P") and by Duff &
Phelps Credit Rating Co. ("DCR"), that the Class X and Class IP Certificates
each be rated "AAAr" by S&P and "AAA" by DCR and that the Class IB-1 and Class
IIB-1 Certificates be rated not less than "AA" by DCR, the Class IB-2 and Class
IIB-2 Certificates be rated not less than "A" by DCR and the Class IB-3 and
Class IIB-3 Certificates be rated not less than "BBB" by DCR. A security rating
is not a recommendation to buy, sell or hold securities and may be subject to
revision or withdrawal at any time by the assigning Rating Agency. Each security
rating should be evaluated independently of any other security rating.
 
    The ratings on the Offered Certificates address the likelihood of the
receipt by Certificateholders of all distributions with respect to the
underlying Mortgage Loans to which they are entitled. The ratings do not
represent any assessment of the likelihood that the rate of Principal
Prepayments by Mortgagors might differ from those originally anticipated. As a
result of such differences in the rate of Principal Prepayments,
Certificateholders might suffer a lower than anticipated yield to maturity. See
"Risk Factors" and "Yield and Prepayment Considerations" herein.
 
                                      S-95
<PAGE>
                                                                      APPENDIX A
 
                        PLANNED PRINCIPAL BALANCE TABLES
<TABLE>
<CAPTION>
                                CLASS IA-1 PAC    CLASS IA-2                                                  CLASS IIA-1
DISTRIBUTION DATE                 COMPONENT      PAC COMPONENT    CLASS IA-4     CLASS IA-5    CLASS IA-6    PAC COMPONENT
- ------------------------------  --------------  ---------------  -------------  ------------  ------------  ---------------
<S>                             <C>             <C>              <C>            <C>           <C>           <C>
Initial Balance...............  1$1,330,672.00   $7,984,500.00   $44,000,000.00 $8,820,291.00 $4,779,258.00  $2,111,439.00
May 25, 1997..................  10,939,574.07     7,708,901.04   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
June 25, 1997.................  10,532,702.12     7,422,186.44   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
July 25, 1997.................  10,110,276.52     7,124,511.49   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
August 25, 1997...............   9,672,527.00     6,816,038.08   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
September 25, 1997............   9,219,692.42     6,496,934.53   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
October 25, 1997..............   8,752,020.65     6,167,375.50   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
November 25, 1997.............   8,269,768.34     5,827,541.85   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
December 25, 1997.............   7,773,200.75     5,477,620.52   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
January 25, 1998..............   7,262,591.57     5,117,804.34   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
February 25, 1998.............   6,738,222.66     4,748,291.97   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
March 25, 1998................   6,200,383.89     4,369,287.65   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
April 25, 1998................   5,649,372.86     3,981,001.09   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
May 25, 1998..................   5,085,494.71     3,583,647.33   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
June 25, 1998.................   4,509,061.84     3,177,446.52   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
July 25, 1998.................   3,920,393.72     2,762,623.76   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
August 25, 1998...............   3,319,816.56     2,339,408.94   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
September 25, 1998............   2,707,663.11     1,908,036.53   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
October 25, 1998..............   2,084,272.36     1,468,745.42   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
November 25, 1998.............   1,449,989.28     1,021,778.71   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
December 25, 1998.............     805,164.52       567,383.48   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
January 25, 1999..............     163,965.54       115,543.27   44,000,000.00  8,820,291.00  4,779,258.00    2,111,439.00
February 25, 1999.............           0.00             0.00   43,192,641.61  8,820,291.00  4,779,258.00    2,111,439.00
March 25, 1999................           0.00             0.00   42,111,938.17  8,820,291.00  4,779,258.00    2,111,439.00
April 25, 1999................           0.00             0.00   41,037,390.73  8,820,291.00  4,779,258.00    2,111,439.00
May 25, 1999..................           0.00             0.00   39,969,755.48  8,820,291.00  4,779,258.00    2,111,439.00
June 25, 1999.................           0.00             0.00   38,909,004.97  8,820,291.00  4,779,258.00    2,111,439.00
July 25, 1999.................           0.00             0.00   37,855,111.93  8,820,291.00  4,779,258.00    2,111,439.00
August 25, 1999...............           0.00             0.00   36,808,049.34  8,820,291.00  4,779,258.00    2,111,439.00
September 25, 1999............           0.00             0.00   35,767,790.39  8,820,291.00  4,779,258.00    2,111,439.00
October 25, 1999..............           0.00             0.00   34,734,308.46  8,820,291.00  4,779,258.00    2,111,439.00
November 25, 1999.............           0.00             0.00   33,707,577.17  8,820,291.00  4,779,258.00    2,111,439.00
December 25, 1999.............           0.00             0.00   32,687,570.34  8,820,291.00  4,779,258.00    2,111,439.00
January 25, 2000..............           0.00             0.00   31,674,261.98  8,820,291.00  4,779,258.00    2,111,439.00
February 25, 2000.............           0.00             0.00   30,667,626.36  8,820,291.00  4,779,258.00    2,111,439.00
March 25, 2000................           0.00             0.00   29,667,637.90  8,820,291.00  4,779,258.00    2,111,439.00
 
<CAPTION>
 
DISTRIBUTION DATE                CLASS IIA-2    CLASS IIA-6    CLASS IIA-7
- ------------------------------  -------------  -------------  -------------
<S>                             <C>            <C>            <C>
Initial Balance...............  $28,500,000.00 $16,000,000.00 $19,587,131.00
May 25, 1997..................  28,500,000.00  16,000,000.00  19,587,131.00
June 25, 1997.................  28,500,000.00  16,000,000.00  19,587,131.00
July 25, 1997.................  28,500,000.00  16,000,000.00  19,587,131.00
August 25, 1997...............  28,500,000.00  16,000,000.00  19,587,131.00
September 25, 1997............  28,500,000.00  16,000,000.00  19,587,131.00
October 25, 1997..............  28,500,000.00  16,000,000.00  19,587,131.00
November 25, 1997.............  28,500,000.00  16,000,000.00  19,587,131.00
December 25, 1997.............  28,500,000.00  16,000,000.00  19,587,131.00
January 25, 1998..............  28,500,000.00  16,000,000.00  19,587,131.00
February 25, 1998.............  28,500,000.00  16,000,000.00  19,587,131.00
March 25, 1998................  28,500,000.00  16,000,000.00  19,587,131.00
April 25, 1998................  28,500,000.00  16,000,000.00  19,587,131.00
May 25, 1998..................  28,500,000.00  16,000,000.00  19,587,131.00
June 25, 1998.................  28,500,000.00  16,000,000.00  19,587,131.00
July 25, 1998.................  28,500,000.00  16,000,000.00  19,587,131.00
August 25, 1998...............  28,500,000.00  16,000,000.00  19,587,131.00
September 25, 1998............  28,500,000.00  16,000,000.00  19,587,131.00
October 25, 1998..............  28,500,000.00  16,000,000.00  19,587,131.00
November 25, 1998.............  28,500,000.00  16,000,000.00  19,587,131.00
December 25, 1998.............  28,500,000.00  16,000,000.00  19,587,131.00
January 25, 1999..............  28,500,000.00  16,000,000.00  19,587,131.00
February 25, 1999.............  28,500,000.00  16,000,000.00  19,587,131.00
March 25, 1999................  26,878,389.42  16,000,000.00  19,587,131.00
April 25, 1999................  25,205,591.49  16,000,000.00  19,587,131.00
May 25, 1999..................  23,482,371.61  16,000,000.00  19,587,131.00
June 25, 1999.................  21,709,520.37  16,000,000.00  19,587,131.00
July 25, 1999.................  19,887,853.02  16,000,000.00  19,587,131.00
August 25, 1999...............  18,018,208.88  16,000,000.00  19,587,131.00
September 25, 1999............  16,158,602.81  16,000,000.00  19,587,131.00
October 25, 1999..............  14,308,988.21  16,000,000.00  19,587,131.00
November 25, 1999.............  12,469,318.80  16,000,000.00  19,587,131.00
December 25, 1999.............  10,639,548.56  16,000,000.00  19,587,131.00
January 25, 2000..............   8,819,631.74  16,000,000.00  19,587,131.00
February 25, 2000.............   7,009,522.88  16,000,000.00  19,587,131.00
March 25, 2000................   5,209,176.77  16,000,000.00  19,587,131.00
</TABLE>
 
                                      S-96
<PAGE>
                        PLANNED PRINCIPAL BALANCE TABLES
<TABLE>
<CAPTION>
                                CLASS IA-1 PAC    CLASS IA-2                                                  CLASS IIA-1
DISTRIBUTION DATE                 COMPONENT      PAC COMPONENT    CLASS IA-4     CLASS IA-5    CLASS IA-6    PAC COMPONENT
- ------------------------------  --------------  ---------------  -------------  ------------  ------------  ---------------
<S>                             <C>             <C>              <C>            <C>           <C>           <C>
April 25, 2000................   $       0.00    $        0.00   $28,674,271.29 $8,820,291.00 $4,779,258.00  $2,111,439.00
May 25, 2000..................           0.00             0.00   27,687,501.37  8,820,291.00  4,779,258.00    2,111,439.00
June 25, 2000.................           0.00             0.00   26,707,303.23  8,820,291.00  4,779,258.00    2,111,439.00
July 25, 2000.................           0.00             0.00   25,733,652.15  8,820,291.00  4,779,258.00    2,111,439.00
August 25, 2000...............           0.00             0.00   24,766,523.61  8,820,291.00  4,779,258.00    2,111,439.00
September 25, 2000............           0.00             0.00   23,805,893.32  8,820,291.00  4,779,258.00    2,111,439.00
October 25, 2000..............           0.00             0.00   22,851,737.16  8,820,291.00  4,779,258.00    2,111,439.00
November 25, 2000.............           0.00             0.00   21,904,031.25  8,820,291.00  4,779,258.00    2,111,439.00
December 25, 2000.............           0.00             0.00   20,962,751.89  8,820,291.00  4,779,258.00    2,111,439.00
January 25, 2001..............           0.00             0.00   20,027,875.59  8,820,291.00  4,779,258.00    2,111,439.00
February 25, 2001.............           0.00             0.00   19,099,379.06  8,820,291.00  4,779,258.00    2,111,439.00
March 25, 2001................           0.00             0.00   18,177,239.21  8,820,291.00  4,779,258.00    2,111,439.00
April 25, 2001................           0.00             0.00   17,261,433.17  8,820,291.00  4,779,258.00    2,111,439.00
May 25, 2001..................           0.00             0.00   16,351,938.25  8,820,291.00  4,779,258.00    2,111,439.00
June 25, 2001.................           0.00             0.00   15,448,731.96  8,820,291.00  4,779,258.00    2,111,439.00
July 25, 2001.................           0.00             0.00   14,551,792.03  8,820,291.00  4,779,258.00    2,111,439.00
August 25, 2001...............           0.00             0.00   13,661,096.37  8,820,291.00  4,779,258.00    2,111,439.00
September 25, 2001............           0.00             0.00   12,776,623.08  8,820,291.00  4,779,258.00    2,111,439.00
October 25, 2001..............           0.00             0.00   11,898,350.49  8,820,291.00  4,779,258.00    2,111,439.00
November 25, 2001.............           0.00             0.00   11,026,257.10  8,820,291.00  4,779,258.00    2,111,439.00
December 25, 2001.............           0.00             0.00   10,160,321.62  8,820,291.00  4,779,258.00    2,111,439.00
January 25, 2002..............           0.00             0.00    9,300,522.95  8,820,291.00  4,779,258.00    2,111,439.00
February 25, 2002.............           0.00             0.00    8,446,840.19  8,820,291.00  4,779,258.00    2,111,439.00
March 25, 2002................           0.00             0.00    7,599,252.63  8,820,291.00  4,779,258.00    2,111,439.00
April 25, 2002................           0.00             0.00    6,757,739.75  8,820,291.00  4,779,258.00      945,243.83
May 25, 2002..................           0.00             0.00    5,982,475.80  8,820,291.00  4,779,258.00            0.00
June 25, 2002.................           0.00             0.00    5,226,711.16  8,820,291.00  4,779,258.00            0.00
July 25, 2002.................           0.00             0.00    4,490,081.89  8,820,291.00  4,779,258.00            0.00
August 25, 2002...............           0.00             0.00    3,772,230.40  8,820,291.00  4,779,258.00            0.00
September 25, 2002............           0.00             0.00    3,072,805.35  8,820,291.00  4,779,258.00            0.00
October 25, 2002..............           0.00             0.00    2,391,461.52  8,820,291.00  4,779,258.00            0.00
November 25, 2002.............           0.00             0.00    1,727,859.74  8,820,291.00  4,779,258.00            0.00
December 25, 2002.............           0.00             0.00    1,081,666.73  8,820,291.00  4,779,258.00            0.00
January 25, 2003..............           0.00             0.00      452,555.09  8,820,291.00  4,779,258.00            0.00
February 25, 2003.............           0.00             0.00            0.00  8,660,494.11  4,779,258.00            0.00
March 25, 2003................           0.00             0.00            0.00  8,064,585.72  4,779,258.00            0.00
April 25, 2003................           0.00             0.00            0.00  7,484,810.39  4,779,258.00            0.00
May 25, 2003..................           0.00             0.00            0.00  6,960,044.49  4,779,258.00            0.00
June 25, 2003.................           0.00             0.00            0.00  6,449,777.25  4,779,258.00            0.00
 
<CAPTION>
 
DISTRIBUTION DATE                CLASS IIA-2    CLASS IIA-6    CLASS IIA-7
- ------------------------------  -------------  -------------  -------------
<S>                             <C>            <C>            <C>
April 25, 2000................  $3,418,548.50  $16,000,000.00 $19,587,131.00
May 25, 2000..................   1,637,593.41  16,000,000.00  19,587,131.00
June 25, 2000.................           0.00  15,866,267.11  19,587,131.00
July 25, 2000.................           0.00  14,104,525.49  19,587,131.00
August 25, 2000...............           0.00  12,352,324.69  19,587,131.00
September 25, 2000............           0.00  10,609,621.13  19,587,131.00
October 25, 2000..............           0.00   8,876,371.50  19,587,131.00
November 25, 2000.............           0.00   7,152,532.74  19,587,131.00
December 25, 2000.............           0.00   5,438,062.05  19,587,131.00
January 25, 2001..............           0.00   3,732,916.91  19,587,131.00
February 25, 2001.............           0.00   2,037,055.04  19,587,131.00
March 25, 2001................           0.00     350,434.45  19,587,131.00
April 25, 2001................           0.00           0.00  18,260,144.37
May 25, 2001..................           0.00           0.00  16,591,881.31
June 25, 2001.................           0.00           0.00  14,932,735.03
July 25, 2001.................           0.00           0.00  13,282,664.57
August 25, 2001...............           0.00           0.00  11,641,629.18
September 25, 2001............           0.00           0.00  10,009,588.39
October 25, 2001..............           0.00           0.00   8,386,501.99
November 25, 2001.............           0.00           0.00   6,772,330.00
December 25, 2001.............           0.00           0.00   5,167,032.70
January 25, 2002..............           0.00           0.00   3,570,570.64
February 25, 2002.............           0.00           0.00   1,982,904.58
March 25, 2002................           0.00           0.00     403,995.55
April 25, 2002................           0.00           0.00           0.00
May 25, 2002..................           0.00           0.00           0.00
June 25, 2002.................           0.00           0.00           0.00
July 25, 2002.................           0.00           0.00           0.00
August 25, 2002...............           0.00           0.00           0.00
September 25, 2002............           0.00           0.00           0.00
October 25, 2002..............           0.00           0.00           0.00
November 25, 2002.............           0.00           0.00           0.00
December 25, 2002.............           0.00           0.00           0.00
January 25, 2003..............           0.00           0.00           0.00
February 25, 2003.............           0.00           0.00           0.00
March 25, 2003................           0.00           0.00           0.00
April 25, 2003................           0.00           0.00           0.00
May 25, 2003..................           0.00           0.00           0.00
June 25, 2003.................           0.00           0.00           0.00
</TABLE>
 
                                      S-97
<PAGE>
                        PLANNED PRINCIPAL BALANCE TABLES
<TABLE>
<CAPTION>
                                CLASS IA-1 PAC    CLASS IA-2                                                  CLASS IIA-1
DISTRIBUTION DATE                 COMPONENT      PAC COMPONENT    CLASS IA-4     CLASS IA-5    CLASS IA-6    PAC COMPONENT
- ------------------------------  --------------  ---------------  -------------  ------------  ------------  ---------------
<S>                             <C>             <C>              <C>            <C>           <C>           <C>
July 25, 2003.................   $       0.00    $        0.00   $        0.00  $5,953,722.51 $4,779,258.00  $        0.00
August 25, 2003...............           0.00             0.00            0.00  5,471,599.21  4,779,258.00            0.00
September 25, 2003............           0.00             0.00            0.00  5,003,131.30  4,779,258.00            0.00
October 25, 2003..............           0.00             0.00            0.00  4,548,047.66  4,779,258.00            0.00
November 25, 2003.............           0.00             0.00            0.00  4,106,082.03  4,779,258.00            0.00
December 25, 2003.............           0.00             0.00            0.00  3,676,972.90  4,779,258.00            0.00
January 25, 2004..............           0.00             0.00            0.00  3,260,463.45  4,779,258.00            0.00
February 25, 2004.............           0.00             0.00            0.00  2,856,301.47  4,779,258.00            0.00
March 25, 2004................           0.00             0.00            0.00  2,464,239.24  4,779,258.00            0.00
April 25, 2004................           0.00             0.00            0.00  2,084,033.52  4,779,258.00            0.00
May 25, 2004..................           0.00             0.00            0.00  1,781,157.32  4,779,258.00            0.00
June 25, 2004.................           0.00             0.00            0.00  1,487,432.02  4,779,258.00            0.00
July 25, 2004.................           0.00             0.00            0.00  1,202,658.03  4,779,258.00            0.00
August 25, 2004...............           0.00             0.00            0.00    926,639.55  4,779,258.00            0.00
September 25, 2004............           0.00             0.00            0.00    659,184.48  4,779,258.00            0.00
October 25, 2004..............           0.00             0.00            0.00    400,104.40  4,779,258.00            0.00
November 25, 2004.............           0.00             0.00            0.00    149,214.50  4,779,258.00            0.00
December 25, 2004.............           0.00             0.00            0.00          0.00  4,685,591.46            0.00
January 25, 2005..............           0.00             0.00            0.00          0.00  4,450,541.46            0.00
February 25, 2005.............           0.00             0.00            0.00          0.00  4,223,148.08            0.00
March 25, 2005................           0.00             0.00            0.00          0.00  4,003,240.22            0.00
April 25, 2005................           0.00             0.00            0.00          0.00  3,790,650.11            0.00
May 25, 2005..................           0.00             0.00            0.00          0.00  3,637,145.21            0.00
June 25, 2005.................           0.00             0.00            0.00          0.00  3,488,335.97            0.00
July 25, 2005.................           0.00             0.00            0.00          0.00  3,344,112.27            0.00
August 25, 2005...............           0.00             0.00            0.00          0.00  3,204,366.21            0.00
September 25, 2005............           0.00             0.00            0.00          0.00  3,068,992.09            0.00
October 25, 2005..............           0.00             0.00            0.00          0.00  2,937,886.41            0.00
November 25, 2005.............           0.00             0.00            0.00          0.00  2,810,947.78            0.00
December 25, 2005.............           0.00             0.00            0.00          0.00  2,688,076.87            0.00
January 25, 2006..............           0.00             0.00            0.00          0.00  2,569,176.43            0.00
February 25, 2006.............           0.00             0.00            0.00          0.00  2,454,151.22            0.00
March 25, 2006................           0.00             0.00            0.00          0.00  2,342,907.93            0.00
April 25, 2006................           0.00             0.00            0.00          0.00  2,235,355.21            0.00
May 25, 2006..................           0.00             0.00            0.00          0.00  2,169,799.99            0.00
June 25, 2006.................           0.00             0.00            0.00          0.00  2,105,610.78            0.00
July 25, 2006.................           0.00             0.00            0.00          0.00  2,042,762.25            0.00
 
<CAPTION>
 
DISTRIBUTION DATE                CLASS IIA-2    CLASS IIA-6    CLASS IIA-7
- ------------------------------  -------------  -------------  -------------
<S>                             <C>            <C>            <C>
July 25, 2003.................  $        0.00  $        0.00  $        0.00
August 25, 2003...............           0.00           0.00           0.00
September 25, 2003............           0.00           0.00           0.00
October 25, 2003..............           0.00           0.00           0.00
November 25, 2003.............           0.00           0.00           0.00
December 25, 2003.............           0.00           0.00           0.00
January 25, 2004..............           0.00           0.00           0.00
February 25, 2004.............           0.00           0.00           0.00
March 25, 2004................           0.00           0.00           0.00
April 25, 2004................           0.00           0.00           0.00
May 25, 2004..................           0.00           0.00           0.00
June 25, 2004.................           0.00           0.00           0.00
July 25, 2004.................           0.00           0.00           0.00
August 25, 2004...............           0.00           0.00           0.00
September 25, 2004............           0.00           0.00           0.00
October 25, 2004..............           0.00           0.00           0.00
November 25, 2004.............           0.00           0.00           0.00
December 25, 2004.............           0.00           0.00           0.00
January 25, 2005..............           0.00           0.00           0.00
February 25, 2005.............           0.00           0.00           0.00
March 25, 2005................           0.00           0.00           0.00
April 25, 2005................           0.00           0.00           0.00
May 25, 2005..................           0.00           0.00           0.00
June 25, 2005.................           0.00           0.00           0.00
July 25, 2005.................           0.00           0.00           0.00
August 25, 2005...............           0.00           0.00           0.00
September 25, 2005............           0.00           0.00           0.00
October 25, 2005..............           0.00           0.00           0.00
November 25, 2005.............           0.00           0.00           0.00
December 25, 2005.............           0.00           0.00           0.00
January 25, 2006..............           0.00           0.00           0.00
February 25, 2006.............           0.00           0.00           0.00
March 25, 2006................           0.00           0.00           0.00
April 25, 2006................           0.00           0.00           0.00
May 25, 2006..................           0.00           0.00           0.00
June 25, 2006.................           0.00           0.00           0.00
July 25, 2006.................           0.00           0.00           0.00
</TABLE>
 
                                      S-98
<PAGE>
                        PLANNED PRINCIPAL BALANCE TABLES
<TABLE>
<CAPTION>
                                CLASS IA-1 PAC    CLASS IA-2                                                  CLASS IIA-1
DISTRIBUTION DATE                 COMPONENT      PAC COMPONENT    CLASS IA-4     CLASS IA-5    CLASS IA-6    PAC COMPONENT
- ------------------------------  --------------  ---------------  -------------  ------------  ------------  ---------------
<S>                             <C>             <C>              <C>            <C>           <C>           <C>
August 25, 2006...............   $       0.00    $        0.00   $        0.00  $       0.00  $1,981,229.52  $        0.00
September 25, 2006............           0.00             0.00            0.00          0.00  1,920,988.13            0.00
October 25, 2006..............           0.00             0.00            0.00          0.00  1,862,014.08            0.00
November 25, 2006.............           0.00             0.00            0.00          0.00  1,804,283.75            0.00
December 25, 2006.............           0.00             0.00            0.00          0.00  1,747,773.96            0.00
January 25, 2007..............           0.00             0.00            0.00          0.00  1,692,461.95            0.00
February 25, 2007.............           0.00             0.00            0.00          0.00  1,638,325.34            0.00
March 25, 2007................           0.00             0.00            0.00          0.00  1,585,342.16            0.00
April 25, 2007................           0.00             0.00            0.00          0.00  1,533,490.80            0.00
May 25, 2007..................           0.00             0.00            0.00          0.00  1,482,750.07            0.00
June 25, 2007.................           0.00             0.00            0.00          0.00  1,433,099.12            0.00
July 25, 2007.................           0.00             0.00            0.00          0.00  1,384,517.50            0.00
August 25, 2007...............           0.00             0.00            0.00          0.00  1,336,985.09            0.00
September 25, 2007............           0.00             0.00            0.00          0.00  1,290,482.14            0.00
October 25, 2007..............           0.00             0.00            0.00          0.00  1,244,989.27            0.00
November 25, 2007.............           0.00             0.00            0.00          0.00  1,200,487.40            0.00
December 25, 2007.............           0.00             0.00            0.00          0.00  1,156,957.82            0.00
January 25, 2008..............           0.00             0.00            0.00          0.00  1,114,382.15            0.00
February 25, 2008.............           0.00             0.00            0.00          0.00  1,072,742.32            0.00
March 25, 2008................           0.00             0.00            0.00          0.00  1,032,020.59            0.00
April 25, 2008................           0.00             0.00            0.00          0.00    992,199.54            0.00
May 25, 2008..................           0.00             0.00            0.00          0.00    953,262.06            0.00
June 25, 2008.................           0.00             0.00            0.00          0.00    915,191.32            0.00
July 25, 2008.................           0.00             0.00            0.00          0.00    877,970.82            0.00
August 25, 2008...............           0.00             0.00            0.00          0.00    841,584.34            0.00
September 25, 2008............           0.00             0.00            0.00          0.00    806,015.95            0.00
October 25, 2008..............           0.00             0.00            0.00          0.00    771,250.00            0.00
November 25, 2008.............           0.00             0.00            0.00          0.00    737,271.14            0.00
December 25, 2008.............           0.00             0.00            0.00          0.00    704,064.26            0.00
January 25, 2009..............           0.00             0.00            0.00          0.00    671,614.54            0.00
February 25, 2009.............           0.00             0.00            0.00          0.00    639,907.43            0.00
March 25, 2009................           0.00             0.00            0.00          0.00    608,928.63            0.00
April 25, 2009................           0.00             0.00            0.00          0.00    578,664.09            0.00
May 25, 2009..................           0.00             0.00            0.00          0.00    549,100.03            0.00
June 25, 2009.................           0.00             0.00            0.00          0.00    520,222.90            0.00
July 25, 2009.................           0.00             0.00            0.00          0.00    492,019.40            0.00
August 25, 2009...............           0.00             0.00            0.00          0.00    464,476.48            0.00
September 25, 2009............           0.00             0.00            0.00          0.00    437,581.30            0.00
October 25, 2009..............           0.00             0.00            0.00          0.00    411,321.26            0.00
November 25, 2009.............           0.00             0.00            0.00          0.00    385,684.00            0.00
 
<CAPTION>
 
DISTRIBUTION DATE                CLASS IIA-2    CLASS IIA-6    CLASS IIA-7
- ------------------------------  -------------  -------------  -------------
<S>                             <C>            <C>            <C>
August 25, 2006...............  $        0.00  $        0.00  $        0.00
September 25, 2006............           0.00           0.00           0.00
October 25, 2006..............           0.00           0.00           0.00
November 25, 2006.............           0.00           0.00           0.00
December 25, 2006.............           0.00           0.00           0.00
January 25, 2007..............           0.00           0.00           0.00
February 25, 2007.............           0.00           0.00           0.00
March 25, 2007................           0.00           0.00           0.00
April 25, 2007................           0.00           0.00           0.00
May 25, 2007..................           0.00           0.00           0.00
June 25, 2007.................           0.00           0.00           0.00
July 25, 2007.................           0.00           0.00           0.00
August 25, 2007...............           0.00           0.00           0.00
September 25, 2007............           0.00           0.00           0.00
October 25, 2007..............           0.00           0.00           0.00
November 25, 2007.............           0.00           0.00           0.00
December 25, 2007.............           0.00           0.00           0.00
January 25, 2008..............           0.00           0.00           0.00
February 25, 2008.............           0.00           0.00           0.00
March 25, 2008................           0.00           0.00           0.00
April 25, 2008................           0.00           0.00           0.00
May 25, 2008..................           0.00           0.00           0.00
June 25, 2008.................           0.00           0.00           0.00
July 25, 2008.................           0.00           0.00           0.00
August 25, 2008...............           0.00           0.00           0.00
September 25, 2008............           0.00           0.00           0.00
October 25, 2008..............           0.00           0.00           0.00
November 25, 2008.............           0.00           0.00           0.00
December 25, 2008.............           0.00           0.00           0.00
January 25, 2009..............           0.00           0.00           0.00
February 25, 2009.............           0.00           0.00           0.00
March 25, 2009................           0.00           0.00           0.00
April 25, 2009................           0.00           0.00           0.00
May 25, 2009..................           0.00           0.00           0.00
June 25, 2009.................           0.00           0.00           0.00
July 25, 2009.................           0.00           0.00           0.00
August 25, 2009...............           0.00           0.00           0.00
September 25, 2009............           0.00           0.00           0.00
October 25, 2009..............           0.00           0.00           0.00
November 25, 2009.............           0.00           0.00           0.00
</TABLE>
 
                                      S-99
<PAGE>
                        PLANNED PRINCIPAL BALANCE TABLES
<TABLE>
<CAPTION>
                                CLASS IA-1 PAC    CLASS IA-2                                                  CLASS IIA-1
DISTRIBUTION DATE                 COMPONENT      PAC COMPONENT    CLASS IA-4     CLASS IA-5    CLASS IA-6    PAC COMPONENT
- ------------------------------  --------------  ---------------  -------------  ------------  ------------  ---------------
<S>                             <C>             <C>              <C>            <C>           <C>           <C>
December 25, 2009.............   $       0.00    $        0.00   $        0.00  $       0.00  $ 360,657.37   $        0.00
January 25, 2010..............           0.00             0.00            0.00          0.00    336,229.43            0.00
February 25, 2010.............           0.00             0.00            0.00          0.00    312,388.48            0.00
March 25, 2010................           0.00             0.00            0.00          0.00    289,123.01            0.00
April 25, 2010................           0.00             0.00            0.00          0.00    266,421.73            0.00
May 25, 2010..................           0.00             0.00            0.00          0.00    244,273.55            0.00
June 25, 2010.................           0.00             0.00            0.00          0.00    222,667.56            0.00
July 25, 2010.................           0.00             0.00            0.00          0.00    201,593.09            0.00
August 25, 2010...............           0.00             0.00            0.00          0.00    181,039.62            0.00
September 25, 2010............           0.00             0.00            0.00          0.00    160,996.86            0.00
October 25, 2010..............           0.00             0.00            0.00          0.00    141,454.66            0.00
November 25, 2010.............           0.00             0.00            0.00          0.00    122,403.11            0.00
December 25, 2010.............           0.00             0.00            0.00          0.00    103,832.42            0.00
January 25, 2011..............           0.00             0.00            0.00          0.00     85,733.04            0.00
February 25, 2011.............           0.00             0.00            0.00          0.00     68,095.53            0.00
March 25, 2011................           0.00             0.00            0.00          0.00     50,910.68            0.00
April 25, 2011................           0.00             0.00            0.00          0.00     34,169.40            0.00
May 25, 2011..................           0.00             0.00            0.00          0.00     17,862.80            0.00
June 25, 2011.................           0.00             0.00            0.00          0.00      1,982.14            0.00
July 25, 2011.................           0.00             0.00            0.00          0.00      1,466.29            0.00
August 25, 2011...............           0.00             0.00            0.00          0.00        964.01            0.00
September 25, 2011............           0.00             0.00            0.00          0.00        475.03            0.00
October 25, 2011 and
 thereafter...................           0.00             0.00            0.00          0.00          0.00            0.00
 
<CAPTION>
 
DISTRIBUTION DATE                CLASS IIA-2    CLASS IIA-6    CLASS IIA-7
- ------------------------------  -------------  -------------  -------------
<S>                             <C>            <C>            <C>
December 25, 2009.............  $        0.00  $        0.00  $        0.00
January 25, 2010..............           0.00           0.00           0.00
February 25, 2010.............           0.00           0.00           0.00
March 25, 2010................           0.00           0.00           0.00
April 25, 2010................           0.00           0.00           0.00
May 25, 2010..................           0.00           0.00           0.00
June 25, 2010.................           0.00           0.00           0.00
July 25, 2010.................           0.00           0.00           0.00
August 25, 2010...............           0.00           0.00           0.00
September 25, 2010............           0.00           0.00           0.00
October 25, 2010..............           0.00           0.00           0.00
November 25, 2010.............           0.00           0.00           0.00
December 25, 2010.............           0.00           0.00           0.00
January 25, 2011..............           0.00           0.00           0.00
February 25, 2011.............           0.00           0.00           0.00
March 25, 2011................           0.00           0.00           0.00
April 25, 2011................           0.00           0.00           0.00
May 25, 2011..................           0.00           0.00           0.00
June 25, 2011.................           0.00           0.00           0.00
July 25, 2011.................           0.00           0.00           0.00
August 25, 2011...............           0.00           0.00           0.00
September 25, 2011............           0.00           0.00           0.00
October 25, 2011 and
 thereafter...................           0.00           0.00           0.00
</TABLE>
 
                                     S-100
<PAGE>
                                                                      APPENDIX B
 
                       TARGETED PRINCIPAL BALANCES TABLES
 
<TABLE>
<CAPTION>
                                                              CLASS IA-2       CLASS IIA-1
DISTRIBUTION DATE                                           TAC COMPONENT     TAC COMPONENT       CLASS IIA-3
- ---------------------------------------------------------  ----------------  ----------------  -----------------
<S>                                                        <C>               <C>               <C>
Initial Balance..........................................  $  11,800,000.00  $  56,279,967.00  $  139,910,604.00
May 25, 1997.............................................     11,657,393.52     56,631,716.79     138,888,045.24
June 25, 1997............................................     11,503,848.96     56,985,665.02     137,711,869.55
July 25, 1997............................................     11,339,657.63     57,341,825.43     136,382,355.67
August 25, 1997..........................................     11,165,131.02     57,700,211.84     134,899,974.97
September 25, 1997.......................................     10,980,600.28     58,060,838.16     133,265,392.05
October 25, 1997.........................................     10,786,415.48     58,423,718.40     131,479,464.92
November 25, 1997........................................     10,582,944.95     58,788,866.64     129,543,244.89
December 25, 1997........................................     10,370,574.53     59,156,297.06     127,457,975.87
January 25, 1998.........................................     10,149,706.74     59,526,023.91     125,225,093.43
February 25, 1998........................................      9,920,759.98     59,898,061.56     122,846,223.35
March 25, 1998...........................................      9,684,167.61     60,272,424.45     120,323,179.79
April 25, 1998...........................................      9,440,377.04     60,649,127.10     117,657,963.00
May 25, 1998.............................................      9,189,848.75     61,028,184.15     114,852,756.73
June 25, 1998............................................      8,933,055.32     61,409,610.30     111,909,925.07
July 25, 1998............................................      8,670,480.37     61,793,420.36     108,832,009.03
August 25, 1998..........................................      8,402,617.53     62,179,629.24     105,621,722.64
September 25, 1998.......................................      8,129,969.29     62,568,251.92     102,281,948.65
October 25, 1998.........................................      7,853,045.98     62,959,303.50      98,815,733.95
November 25, 1998........................................      7,572,364.55     63,352,799.14      95,226,284.44
December 25, 1998........................................      7,288,447.47     63,748,754.14      91,516,959.71
January 25, 1999.........................................      7,012,045.12     64,147,183.85      87,691,267.23
February 25, 1999........................................      6,743,051.87     64,548,103.75      83,752,856.30
March 25, 1999...........................................      6,481,363.99     64,951,529.40      81,327,122.20
April 25, 1999...........................................      6,226,879.56     65,357,476.46      78,847,555.02
May 25, 1999.............................................      5,979,825.25     65,765,960.68      76,317,424.36
June 25, 1999............................................      5,740,082.03     66,176,997.94      73,740,088.91
July 25, 1999............................................      5,507,532.54     66,590,604.18      71,118,989.47
August 25, 1999..........................................      5,282,061.05     67,006,795.45      68,457,641.69
September 25, 1999.......................................      5,063,553.42     67,425,587.92      65,841,056.04
October 25, 1999.........................................      4,851,897.13     67,846,997.85      63,268,483.68
November 25, 1999........................................      4,646,981.20     68,271,041.59      60,739,185.97
December 25, 1999........................................      4,448,696.23     68,697,735.59      58,252,434.35
January 25, 2000.........................................      4,256,934.32     69,127,096.44      55,807,510.16
February 25, 2000........................................      4,071,589.09     69,559,140.80      53,403,704.56
March 25, 2000...........................................      3,892,555.64     69,993,885.43      51,040,318.30
April 25, 2000...........................................      3,719,730.55     70,431,347.21      48,716,661.69
May 25, 2000.............................................      3,553,011.82     70,871,543.13      46,432,054.39
June 25, 2000............................................      3,392,298.91     71,314,490.27      44,185,825.31
July 25, 2000............................................      3,237,492.66     71,760,205.84      41,977,312.50
August 25, 2000..........................................      3,088,495.31     72,208,707.12      39,805,862.98
September 25, 2000.......................................      2,945,210.49     72,660,011.54      37,670,832.64
October 25, 2000.........................................      2,807,543.16     73,114,136.62      35,571,586.11
November 25, 2000........................................      2,675,399.61     73,571,099.97      33,507,496.64
December 25, 2000........................................      2,548,687.47     74,030,919.34      31,477,945.98
</TABLE>
 
                                     S-101
<PAGE>
                       TARGETED PRINCIPAL BALANCES TABLES
<TABLE>
<CAPTION>
                                                              CLASS IA-2       CLASS IIA-1
DISTRIBUTION DATE                                           TAC COMPONENT     TAC COMPONENT       CLASS IIA-3
- ---------------------------------------------------------  ----------------  ----------------  -----------------
<S>                                                        <C>               <C>               <C>
January 25, 2001.........................................  $   2,427,315.64  $  74,493,612.59  $   29,482,324.25
February 25, 2001........................................      2,311,194.33     74,959,197.67      27,520,029.83
March 25, 2001...........................................      2,200,235.01     75,427,692.65      25,590,469.27
April 25, 2001...........................................      2,094,350.36     75,899,115.73      23,693,057.12
May 25, 2001.............................................      1,993,454.35     76,373,485.21      21,827,215.85
June 25, 2001............................................      1,897,462.11     76,850,819.49      19,992,375.77
July 25, 2001............................................      1,806,290.01     77,331,137.11      18,187,974.83
August 25, 2001..........................................      1,719,855.56     77,814,456.72      16,413,458.63
September 25, 2001.......................................      1,638,077.48     78,300,797.07      14,668,280.20
October 25, 2001.........................................      1,560,875.60     78,790,177.05      12,951,899.97
November 25, 2001........................................      1,488,170.91     79,282,615.66      11,263,785.64
December 25, 2001........................................      1,419,885.51     79,778,132.01       9,603,412.08
January 25, 2002.........................................      1,355,942.61     80,276,745.33       7,970,261.21
February 25, 2002........................................      1,296,266.50     80,778,474.99       6,363,821.94
March 25, 2002...........................................      1,240,782.54     81,283,340.46       4,783,590.03
April 25, 2002...........................................      1,189,417.18     81,791,361.34       3,229,068.03
May 25, 2002.............................................      1,158,097.61     82,302,557.35       1,423,713.38
June 25, 2002............................................      1,125,466.96     81,521,347.14               0.00
July 25, 2002............................................      1,091,572.96     79,350,409.30               0.00
August 25, 2002..........................................      1,056,462.18     77,212,970.75               0.00
September 25, 2002.......................................      1,020,180.07     75,108,551.67               0.00
October 25, 2002.........................................        982,770.96     73,036,678.77               0.00
November 25, 2002........................................        944,278.10     70,996,885.20               0.00
December 25, 2002........................................        904,743.68     68,988,710.45               0.00
January 25, 2003.........................................        864,208.86     67,011,700.29               0.00
February 25, 2003........................................        822,713.75     65,065,406.66               0.00
March 25, 2003...........................................        780,297.51     63,149,387.60               0.00
April 25, 2003...........................................        736,998.27     61,263,207.18               0.00
May 25, 2003.............................................        690,063.67     59,513,042.60               0.00
June 25, 2003............................................        642,419.36     57,790,611.47               0.00
July 25, 2003............................................        594,099.07     56,095,503.54               0.00
August 25, 2003..........................................        545,135.66     54,427,314.17               0.00
September 25, 2003.......................................        495,561.13     52,785,644.32               0.00
October 25, 2003.........................................        445,406.63     51,170,100.40               0.00
November 25, 2003........................................        394,702.45     49,580,294.26               0.00
December 25, 2003........................................        343,478.10     48,015,843.06               0.00
January 25, 2004.........................................        291,762.28     46,476,369.26               0.00
February 25, 2004........................................        239,582.92     44,961,500.46               0.00
March 25, 2004...........................................        186,967.17     43,470,869.44               0.00
April 25, 2004...........................................        133,941.46     42,004,113.98               0.00
May 25, 2004.............................................         76,164.64     40,757,824.73               0.00
June 25, 2004............................................         18,241.35     39,531,550.74               0.00
July 25, 2004............................................              0.00     38,324,976.69               0.00
August 25, 2004..........................................              0.00     37,137,791.74               0.00
September 25, 2004.......................................              0.00     35,969,689.45               0.00
October 25, 2004.........................................              0.00     34,820,367.78               0.00
</TABLE>
 
                                     S-102
<PAGE>
                       TARGETED PRINCIPAL BALANCES TABLES
<TABLE>
<CAPTION>
                                                              CLASS IA-2       CLASS IIA-1
DISTRIBUTION DATE                                           TAC COMPONENT     TAC COMPONENT       CLASS IIA-3
- ---------------------------------------------------------  ----------------  ----------------  -----------------
<S>                                                        <C>               <C>               <C>
November 25, 2004........................................  $           0.00  $  33,689,528.96  $            0.00
December 25, 2004........................................              0.00     32,576,879.45               0.00
January 25, 2005.........................................              0.00     31,482,129.89               0.00
February 25, 2005........................................              0.00     30,404,995.06               0.00
March 25, 2005...........................................              0.00     29,345,193.78               0.00
April 25, 2005...........................................              0.00     28,302,448.87               0.00
May 25, 2005.............................................              0.00     27,452,330.89               0.00
June 25, 2005............................................              0.00     26,614,923.00               0.00
July 25, 2005............................................              0.00     25,790,015.74               0.00
August 25, 2005..........................................              0.00     24,977,402.69               0.00
September 25, 2005.......................................              0.00     24,176,880.48               0.00
October 25, 2005.........................................              0.00     23,388,248.67               0.00
November 25, 2005........................................              0.00     22,611,309.79               0.00
December 25, 2005........................................              0.00     21,845,869.24               0.00
January 25, 2006.........................................              0.00     21,091,735.25               0.00
February 25, 2006........................................              0.00     20,348,718.86               0.00
March 25, 2006...........................................              0.00     19,616,633.90               0.00
April 25, 2006...........................................              0.00     18,895,296.88               0.00
May 25, 2006.............................................              0.00     18,336,241.94               0.00
June 25, 2006............................................              0.00     17,783,435.02               0.00
July 25, 2006............................................              0.00     17,236,779.85               0.00
August 25, 2006..........................................              0.00     16,696,181.38               0.00
September 25, 2006.......................................              0.00     16,161,545.83               0.00
October 25, 2006.........................................              0.00     15,632,780.59               0.00
November 25, 2006........................................              0.00     15,109,794.27               0.00
December 25, 2006........................................              0.00     14,592,496.67               0.00
January 25, 2007.........................................              0.00     14,080,798.73               0.00
February 25, 2007........................................              0.00     13,574,612.54               0.00
March 25, 2007...........................................              0.00     13,073,851.34               0.00
April 25, 2007...........................................              0.00     12,578,429.48               0.00
May 25, 2007.............................................              0.00     12,088,262.39               0.00
June 25, 2007............................................              0.00     11,603,266.61               0.00
July 25, 2007............................................              0.00     11,123,359.73               0.00
August 25, 2007..........................................              0.00     10,648,460.42               0.00
September 25, 2007.......................................              0.00     10,178,488.36               0.00
October 25, 2007.........................................              0.00      9,713,364.28               0.00
November 25, 2007........................................              0.00      9,253,009.90               0.00
December 25, 2007........................................              0.00      8,797,347.97               0.00
January 25, 2008.........................................              0.00      8,346,302.18               0.00
February 25, 2008........................................              0.00      7,899,797.23               0.00
March 25, 2008...........................................              0.00      7,457,758.75               0.00
April 25, 2008...........................................              0.00      7,020,113.32               0.00
May 25, 2008.............................................              0.00      6,586,788.46               0.00
June 25, 2008............................................              0.00      6,157,712.58               0.00
July 25, 2008............................................              0.00      5,732,815.02               0.00
August 25, 2008..........................................              0.00      5,312,026.00               0.00
</TABLE>
 
                                     S-103
<PAGE>
                       TARGETED PRINCIPAL BALANCES TABLES
<TABLE>
<CAPTION>
                                                              CLASS IA-2       CLASS IIA-1
DISTRIBUTION DATE                                           TAC COMPONENT     TAC COMPONENT       CLASS IIA-3
- ---------------------------------------------------------  ----------------  ----------------  -----------------
<S>                                                        <C>               <C>               <C>
September 25, 2008.......................................  $           0.00  $   4,895,276.61  $            0.00
October 25, 2008.........................................              0.00      4,482,498.83               0.00
November 25, 2008........................................              0.00      4,073,625.47               0.00
December 25, 2008........................................              0.00      3,668,590.20               0.00
January 25, 2009.........................................              0.00      3,267,327.50               0.00
February 25, 2009........................................              0.00      2,869,772.68               0.00
March 25, 2009...........................................              0.00      2,475,861.85               0.00
April 25, 2009...........................................              0.00      2,085,531.93               0.00
May 25, 2009.............................................              0.00      1,698,720.61               0.00
June 25, 2009............................................              0.00      1,315,366.36               0.00
July 25, 2009............................................              0.00        935,408.40               0.00
August 25, 2009..........................................              0.00        558,786.72               0.00
September 25, 2009.......................................              0.00        185,442.04               0.00
October 25, 2009 and thereafter..........................              0.00              0.00               0.00
</TABLE>
 
                                     S-104
<PAGE>
                                                                     APPENDIX C+
 
                     GROUP 1 LOANS - 15 YEAR MORTGAGE LOANS
             PERCENT OF INITIAL CLASS PRINCIPAL BALANCE OUTSTANDING
           AT VARIOUS PERCENTAGES OF THE BASIC PREPAYMENT ASSUMPTION
<TABLE>
<CAPTION>
                                                                     CLASS IA-1
<S>                                       <C>        <C>        <C>        <C>        <C>        <C>
                                          ----------------------------------------------------------------
 
<CAPTION>
DISTRIBUTION DATE                            0%        105%       175%       240%       300%       500%
- ----------------------------------------  ----------------------------------------------------------------
<S>                                       <C>        <C>        <C>        <C>        <C>        <C>
Initial Percentage......................        100%       100%       100%       100%       100%       100%
April 25, 1998..........................         93         84         78         73         68         51
April 25, 1999..........................         84         69         55         42         30          0
April 25, 2000..........................         76         69         48         29         14          0
April 25, 2001..........................         69         69         43         22          4          0
April 25, 2002..........................         69         69         40         18          0          0
April 25, 2003..........................         69         67         38         16          0          0
April 25, 2004..........................         69         62         34         14          0          0
April 25, 2005..........................         69         54         29         12          0          0
April 25, 2006..........................         69         45         23          9          0          0
April 25, 2007..........................         69         36         18          7          0          0
April 25, 2008..........................         66         27         13          4          0          0
April 25, 2009..........................         47         18          8          3          0          0
April 25, 2010..........................         26         10          4          1          0          0
April 25, 2011..........................          4          1          1          *          0          0
April 25, 2012..........................          0          0          0          0          0          0
Weighted Average Life (Years)(1)........        9.3        7.3        4.8        3.0        1.7        1.0
 
<CAPTION>
                                                                   CLASS IA-2
<S>                                       <C>     <C>        <C>        <C>        <C>        <C>
                                          -------------------------------------------------------------
DISTRIBUTION DATE                           0%      105%       175%       240%       300%       500%
- ----------------------------------------  -------------------------------------------------------------
<S>                                       <C>     <C>        <C>        <C>        <C>        <C>
Initial Percentage......................     100%       100%       100%       100%       100%       100   %
April 25, 1998..........................      90         79         73         68         68         55
April 25, 1999..........................      78         58         44         31         29          0
April 25, 2000..........................      66         58         37         19         13          0
April 25, 2001..........................      57         57         32         11          4          0
April 25, 2002..........................      56         56         28          6          0          0
April 25, 2003..........................      55         54         25          4          0          0
April 25, 2004..........................      54         48         20          1          0          0
April 25, 2005..........................      54         39         14          0          0          0
April 25, 2006..........................      53         29          7          0          0          0
April 25, 2007..........................      51         19          1          0          0          0
April 25, 2008..........................      47          9          0          0          0          0
April 25, 2009..........................      27          0          0          0          0          0
April 25, 2010..........................       6          0          0          0          0          0
April 25, 2011..........................       0          0          0          0          0          0
April 25, 2012..........................       0          0          0          0          0          0
Weighted Average Life (Years)(1)........     7.5        5.6        3.3        1.9        1.7        1.1
 
<CAPTION>
                                                                   CLASS IA-3
                                          -------------------------------------------------------------
DISTRIBUTION DATE                           0%      105%       175%       240%       300%       500%
- ----------------------------------------  -------------------------------------------------------------
Initial Percentage......................     100%       100%       100%       100%       100%       100%
April 25, 1998..........................      96         96         96         96         96         96
April 25, 1999..........................      92         92         92         92         92         92
April 25, 2000..........................      87         87         87         87         87         87
April 25, 2001..........................      82         82         82         82         82         82
April 25, 2002..........................      76         76         76         76         76         65
April 25, 2003..........................      70         69         68         67         66         40
April 25, 2004..........................      64         61         59         57         56         24
April 25, 2005..........................      57         52         49         47         44         14
April 25, 2006..........................      49         43         39         36         33          8
April 25, 2007..........................      41         34         29         26         22          5
April 25, 2008..........................      33         25         21         17         15          3
April 25, 2009..........................      23         17         13         11          8          1
April 25, 2010..........................      13          9          7          5          4          1
April 25, 2011..........................       2          1          1          1          *          *
April 25, 2012..........................       0          0          0          0          0          0
Weighted Average Life (Years)(1)........     8.4        8.0        7.7        7.5        7.3        5.7
 
<CAPTION>
                                                                   CLASS IA-4
                                          -------------------------------------------------------------
DISTRIBUTION DATE                           0%      105%       175%       240%       300%       500%
- ----------------------------------------  -------------------------------------------------------------
Initial Percentage......................     100%       100%       100%       100%       100%       100%
April 25, 1998..........................     100        100        100        100        100        100
April 25, 1999..........................     100         93         93         93         93         85
April 25, 2000..........................     100         65         65         65         65         24
April 25, 2001..........................      96         39         39         39         39          0
April 25, 2002..........................      82         15         15         15         15          0
April 25, 2003..........................      66          0          0          0          0          0
April 25, 2004..........................      49          0          0          0          0          0
April 25, 2005..........................      31          0          0          0          0          0
April 25, 2006..........................      11          0          0          0          0          0
April 25, 2007..........................       0          0          0          0          0          0
April 25, 2008..........................       0          0          0          0          0          0
April 25, 2009..........................       0          0          0          0          0          0
April 25, 2010..........................       0          0          0          0          0          0
April 25, 2011..........................       0          0          0          0          0          0
April 25, 2012..........................       0          0          0          0          0          0
Weighted Average Life (Years)(1)........     6.9        3.7        3.7        3.7        3.7        2.6
</TABLE>
 
- ----------------------------------
 +  This table has been prepared based on the assumptions described herein under
    "Yield and Prepayment Considerations--General" (including the assumptions
    regarding the characteristics and performance of the Mortgage Loans which
    differ from the actual characteristics and performance thereof) and should
    be read in conjunction therewith.
 
 *  Indicates an amount above zero and less than 0.5% of original principal
    balance outstanding.
 
(1) The weighted average life of any Class of Certificates is determined by (i)
    multiplying the amount of each assumed principal distribution on such Class
    of Certificates by the number of years from the date of issuance of the
    Certificates to the related Distribution Date, (ii) summing the results, and
    (iii) dividing the sum by the total amount of principal distributed on such
    Class of Certificates.
 
                                     S-105
<PAGE>
                     GROUP 1 LOANS - 15 YEAR MORTGAGE LOANS
             PERCENT OF INITIAL CLASS PRINCIPAL BALANCE OUTSTANDING
           AT VARIOUS PERCENTAGES OF THE BASIC PREPAYMENT ASSUMPTION
<TABLE>
<CAPTION>
                                                                     CLASS IA-5
<S>                                       <C>        <C>        <C>        <C>        <C>        <C>
                                          ----------------------------------------------------------------
 
<CAPTION>
DISTRIBUTION DATE                            0%        105%       175%       240%       300%       500%
- ----------------------------------------  ----------------------------------------------------------------
<S>                                       <C>        <C>        <C>        <C>        <C>        <C>
Initial Percentage......................        100%       100%       100%       100%       100%       100%
April 25, 1998..........................        100        100        100        100        100        100
April 25, 1999..........................        100        100        100        100        100        100
April 25, 2000..........................        100        100        100        100        100        100
April 25, 2001..........................        100        100        100        100        100         27
April 25, 2002..........................        100        100        100        100        100          0
April 25, 2003..........................        100         85         85         85         85          0
April 25, 2004..........................        100         24         24         24         24          0
April 25, 2005..........................        100          0          0          0          0          0
April 25, 2006..........................        100          0          0          0          0          0
April 25, 2007..........................         50          0          0          0          0          0
April 25, 2008..........................          0          0          0          0          0          0
April 25, 2009..........................          0          0          0          0          0          0
April 25, 2010..........................          0          0          0          0          0          0
April 25, 2011..........................          0          0          0          0          0          0
April 25, 2012..........................          0          0          0          0          0          0
Weighted Average Life (Years)(1)........       10.0        6.6        6.6        6.6        6.6        3.9
 
<CAPTION>
                                                                   CLASS IA-6
<S>                                       <C>     <C>        <C>        <C>        <C>        <C>
                                          -------------------------------------------------------------
DISTRIBUTION DATE                           0%      105%       175%       240%       300%       500%
- ----------------------------------------  -------------------------------------------------------------
<S>                                       <C>     <C>        <C>        <C>        <C>        <C>
Initial Percentage......................     100%       100%       100%       100%       100%       100   %
April 25, 1998..........................     100        100        100        100        100        100
April 25, 1999..........................     100        100        100        100        100        100
April 25, 2000..........................     100        100        100        100        100        100
April 25, 2001..........................     100        100        100        100        100        100
April 25, 2002..........................     100        100        100        100        100          0
April 25, 2003..........................     100        100        100        100        100          0
April 25, 2004..........................     100        100        100        100        100          0
April 25, 2005..........................     100         79         79         79         79          0
April 25, 2006..........................     100         47         47         47         47          0
April 25, 2007..........................     100         32         32         32         32          0
April 25, 2008..........................      21         21         21         21         21          0
April 25, 2009..........................      12         12         12         12         12          0
April 25, 2010..........................       6          6          6          6          6          0
April 25, 2011..........................       1          1          1          1          1          0
April 25, 2012..........................       0          0          0          0          0          0
Weighted Average Life (Years)(1)........    11.0        9.5        9.5        9.5        9.5        4.4
 
<CAPTION>
                                                                   CLASS IA-7
                                          -------------------------------------------------------------
DISTRIBUTION DATE                           0%      105%       175%       240%       300%       500%
- ----------------------------------------  -------------------------------------------------------------
Initial Percentage......................     100%       100%       100%       100%       100%       100%
April 25, 1998..........................     107        107        107        107         45          0
April 25, 1999..........................     115        115        115        115          0          0
April 25, 2000..........................     123        123        123        123          0          0
April 25, 2001..........................     132        132        132        132          0          0
April 25, 2002..........................     142        142        142        142          0          0
April 25, 2003..........................     152        152        152        152          0          0
April 25, 2004..........................     163        163        163        163          0          0
April 25, 2005..........................     175        175        175        140          0          0
April 25, 2006..........................     187        187        187        108          0          0
April 25, 2007..........................     201        201        201         79          0          0
April 25, 2008..........................     215        215        151         54          0          0
April 25, 2009..........................     231        217         98         33          0          0
April 25, 2010..........................     248        115         50         16          0          0
April 25, 2011..........................      50         17          7          2          0          0
April 25, 2012..........................       0          0          0          0          0          0
Weighted Average Life (Years)(1)........    13.8       13.0       12.0       10.1        0.9        0.3
 
<CAPTION>
                                                                    CLASS IP
                                          -------------------------------------------------------------
DISTRIBUTION DATE                           0%      105%       175%       240%       300%       500%
- ----------------------------------------  -------------------------------------------------------------
Initial Percentage......................     100%       100%       100%       100%       100%       100%
April 25, 1998..........................      96         93         92         90         89         84
April 25, 1999..........................      92         85         80         76         72         60
April 25, 2000..........................      87         75         68         62         56         40
April 25, 2001..........................      82         66         57         50         43         26
April 25, 2002..........................      76         58         48         40         33         17
April 25, 2003..........................      70         50         40         31         25         11
April 25, 2004..........................      64         43         32         24         19          7
April 25, 2005..........................      57         36         26         19         14          4
April 25, 2006..........................      50         29         20         14         10          3
April 25, 2007..........................      43         23         15         10          7          2
April 25, 2008..........................      34         18         11          7          5          1
April 25, 2009..........................      25         12          7          4          3          *
April 25, 2010..........................      16          7          4          2          1          *
April 25, 2011..........................       5          2          1          1          *          *
April 25, 2012..........................       0          0          0          0          0          0
Weighted Average Life (Years)(1)........     8.5        6.5        5.5        4.8        4.3        3.1
</TABLE>
 
- ----------------------------------
 *  Indicates an amount above zero and less than 0.5% of original principal
    balance outstanding.
 
(1) The weighted average life of any Class of Certificates is determined by (i)
    multiplying the amount of each assumed principal distribution on such Class
    of Certificates by the number of years from the date of issuance of the
    Certificates to the related Distribution Date, (ii) summing the results, and
    (iii) dividing the sum by the total amount of principal distributed on such
    Class of Certificates.
 
                                     S-106
<PAGE>
                     GROUP 1 LOANS - 15 YEAR MORTGAGE LOANS
             PERCENT OF INITIAL CLASS PRINCIPAL BALANCE OUTSTANDING
           AT VARIOUS PERCENTAGES OF THE BASIC PREPAYMENT ASSUMPTION
<TABLE>
<CAPTION>
                                                                            CLASS R
<S>                                       <C>          <C>          <C>          <C>          <C>          <C>
                                          ----------------------------------------------------------------------------
 
<CAPTION>
DISTRIBUTION DATE                             0%          105%         175%         240%         300%         500%
- ----------------------------------------  ----------------------------------------------------------------------------
<S>                                       <C>          <C>          <C>          <C>          <C>          <C>
Initial Percentage......................         100%         100%         100%         100%         100%         100%
April 25, 1998..........................         100          100          100          100          100          100
April 25, 1999..........................         100          100          100          100          100            0
April 25, 2000..........................         100          100          100          100          100            0
April 25, 2001..........................         100          100          100          100          100            0
April 25, 2002..........................         100          100          100          100            2            0
April 25, 2003..........................         100          100          100          100            2            0
April 25, 2004..........................         100          100          100          100            2            0
April 25, 2005..........................         100          100          100          100            2            0
April 25, 2006..........................         100          100          100          100            2            0
April 25, 2007..........................         100          100          100          100            2            0
April 25, 2008..........................         100          100          100          100            2            0
April 25, 2009..........................         100          100          100          100            2            0
April 25, 2010..........................         100          100          100          100            2            0
April 25, 2011..........................         100          100          100          100            2            0
April 25, 2012..........................           0            0            0            0            0            0
Weighted Average Life (Years)(1)........        14.5         14.5         14.5         14.5          5.2          1.8
 
<CAPTION>
                                                                  CLASS IB-1, IB-2 & IB-3
<S>                                       <C>     <C>          <C>          <C>          <C>          <C>
                                          -----------------------------------------------------------------------
DISTRIBUTION DATE                           0%       105%         175%         240%         300%         500%
- ----------------------------------------  -----------------------------------------------------------------------
<S>                                       <C>     <C>          <C>          <C>          <C>          <C>
Initial Percentage......................    100 %        100%         100%         100%         100%         100%
April 25, 1998..........................     96           96           96           96           96           96
April 25, 1999..........................     92           92           92           92           92           92
April 25, 2000..........................     87           87           87           87           87           87
April 25, 2001..........................     82           82           82           82           82           82
April 25, 2002..........................     76           76           76           76           76           76
April 25, 2003..........................     70           69           68           67           66           63
April 25, 2004..........................     64           61           59           57           56           50
April 25, 2005..........................     57           52           49           47           44           36
April 25, 2006..........................     49           43           39           36           33           24
April 25, 2007..........................     41           34           29           26           22           14
April 25, 2008..........................     33           25           21           17           15            8
April 25, 2009..........................     23           17           13           11            8            4
April 25, 2010..........................     13            9            7            5            4            1
April 25, 2011..........................      2            1            1            1            *            *
April 25, 2012..........................      0            0            0            0            0            0
Weighted Average Life (Years)(1)........    8.4          8.0          7.7          7.5          7.3          6.8
</TABLE>
 
- ----------------------------------
 *  Indicates an amount above zero and less than 0.5% of original principal
    balance outstanding.
 
(1) The weighted average life of any Class of Certificates is determined by (i)
    multiplying the amount of each assumed principal distribution on such Class
    of Certificates by the number of years from the date of issuance of the
    Certificates to the related Distribution Date, (ii) summing the results, and
    (iii) dividing the sum by the total amount of principal distributed on such
    Class of Certificates.
 
                                     S-107
<PAGE>
                    GROUP II LOANS - 30 YEAR MORTGAGE LOANS
             PERCENT OF INITIAL CLASS PRINCIPAL BALANCE OUTSTANDING
           AT VARIOUS PERCENTAGES OF THE BASIC PREPAYMENT ASSUMPTION
<TABLE>
<CAPTION>
                                                                          CLASS IIA-2
<S>                                       <C>          <C>          <C>          <C>          <C>          <C>
                                          ----------------------------------------------------------------------------
 
<CAPTION>
DISTRIBUTION DATE                             0%          100%         175%         250%         350%         500%
- ----------------------------------------  ----------------------------------------------------------------------------
<S>                                       <C>          <C>          <C>          <C>          <C>          <C>
Initial Percentage......................         100%         100%         100%         100%         100%         100%
April 25, 1998..........................         100          100          100          100          100          100
April 25, 1999..........................          99           88           88           88           88           88
April 25, 2000..........................          89           12           12           12           12           12
April 25, 2001..........................          79            0            0            0            0            0
April 25, 2002..........................          68            0            0            0            0            0
April 25, 2003..........................          57            0            0            0            0            0
April 25, 2004..........................          44            0            0            0            0            0
April 25, 2005..........................          30            0            0            0            0            0
April 25, 2006..........................          15            0            0            0            0            0
April 25, 2007..........................           0            0            0            0            0            0
April 25, 2008..........................           0            0            0            0            0            0
April 25, 2009..........................           0            0            0            0            0            0
April 25, 2010..........................           0            0            0            0            0            0
April 25, 2011..........................           0            0            0            0            0            0
April 25, 2012..........................           0            0            0            0            0            0
April 25, 2013..........................           0            0            0            0            0            0
April 25, 2014..........................           0            0            0            0            0            0
April 25, 2015..........................           0            0            0            0            0            0
April 25, 2016..........................           0            0            0            0            0            0
April 25, 2017..........................           0            0            0            0            0            0
April 25, 2018..........................           0            0            0            0            0            0
April 25, 2019..........................           0            0            0            0            0            0
April 25, 2020..........................           0            0            0            0            0            0
April 25, 2021..........................           0            0            0            0            0            0
April 25, 2022..........................           0            0            0            0            0            0
April 25, 2023..........................           0            0            0            0            0            0
April 25, 2024..........................           0            0            0            0            0            0
April 25, 2025..........................           0            0            0            0            0            0
April 25, 2026..........................           0            0            0            0            0            0
April 25, 2027..........................           0            0            0            0            0            0
Weighted Average Life (Years)(1)........         6.4          2.5          2.5          2.5          2.5          2.5
 
<CAPTION>
                                                                        CLASS IIA-3
<S>                                       <C>     <C>          <C>          <C>          <C>          <C>
                                          -----------------------------------------------------------------------
DISTRIBUTION DATE                           0%       100%         175%         250%         350%         500%
- ----------------------------------------  -----------------------------------------------------------------------
<S>                                       <C>     <C>          <C>          <C>          <C>          <C>
Initial Percentage......................    100 %        100%         100%         100%         100%         100%
April 25, 1998..........................     95           91           87           84           84           78
April 25, 1999..........................     90           77           67           56           48           28
April 25, 2000..........................     86           73           54           35           17            0
April 25, 2001..........................     81           69           42           17            0            0
April 25, 2002..........................     77           64           31            2            0            0
April 25, 2003..........................     72           48           11            0            0            0
April 25, 2004..........................     66           32            0            0            0            0
April 25, 2005..........................     60           16            0            0            0            0
April 25, 2006..........................     54            2            0            0            0            0
April 25, 2007..........................     47            0            0            0            0            0
April 25, 2008..........................     40            0            0            0            0            0
April 25, 2009..........................     32            0            0            0            0            0
April 25, 2010..........................     23            0            0            0            0            0
April 25, 2011..........................     14            0            0            0            0            0
April 25, 2012..........................      4            0            0            0            0            0
April 25, 2013..........................      0            0            0            0            0            0
April 25, 2014..........................      0            0            0            0            0            0
April 25, 2015..........................      0            0            0            0            0            0
April 25, 2016..........................      0            0            0            0            0            0
April 25, 2017..........................      0            0            0            0            0            0
April 25, 2018..........................      0            0            0            0            0            0
April 25, 2019..........................      0            0            0            0            0            0
April 25, 2020..........................      0            0            0            0            0            0
April 25, 2021..........................      0            0            0            0            0            0
April 25, 2022..........................      0            0            0            0            0            0
April 25, 2023..........................      0            0            0            0            0            0
April 25, 2024..........................      0            0            0            0            0            0
April 25, 2025..........................      0            0            0            0            0            0
April 25, 2026..........................      0            0            0            0            0            0
April 25, 2027..........................      0            0            0            0            0            0
Weighted Average Life (Years)(1)........    8.9          5.2          3.4          2.5          2.0          1.6
 
<CAPTION>
                                                                        CLASS IIA-4
                                          -----------------------------------------------------------------------
DISTRIBUTION DATE                           0%       100%         175%         250%         350%         500%
- ----------------------------------------  -----------------------------------------------------------------------
Initial Percentage......................    100 %        100%         100%         100%         100%         100%
April 25, 1998..........................     99           99           99           99           99           99
April 25, 1999..........................     98           98           98           98           98           98
April 25, 2000..........................     97           97           97           97           97           97
April 25, 2001..........................     96           96           96           96           96           96
April 25, 2002..........................     95           95           95           95           95           95
April 25, 2003..........................     94           92           91           89           87           62
April 25, 2004..........................     92           89           86           83           79           40
April 25, 2005..........................     91           84           79           74           67           25
April 25, 2006..........................     89           79           71           64           55           17
April 25, 2007..........................     88           72           62           53           42           12
April 25, 2008..........................     86           67           54           44           33            8
April 25, 2009..........................     84           61           48           37           25            5
April 25, 2010..........................     82           56           42           30           19            4
April 25, 2011..........................     79           51           36           25           15            2
April 25, 2012..........................     77           46           31           21           11            2
April 25, 2013..........................     74           42           27           17            9            1
April 25, 2014..........................     71           38           23           14            7            1
April 25, 2015..........................     68           34           20           11            5            1
April 25, 2016..........................     64           30           17            9            4            *
April 25, 2017..........................     60           27           14            7            3            *
April 25, 2018..........................     56           23           12            6            2            *
April 25, 2019..........................     51           20           10            4            1            *
April 25, 2020..........................     46           17            8            3            1            *
April 25, 2021..........................     41           14            6            3            1            *
April 25, 2022..........................     35           11            5            2            *            *
April 25, 2023..........................     29            9            3            1            *            *
April 25, 2024..........................     22            6            2            1            *            *
April 25, 2025..........................     15            4            1            *            *            *
April 25, 2026..........................      6            2            1            *            *            *
April 25, 2027..........................      0            0            0            0            0            0
Weighted Average Life (Years)(1)........   20.4         15.1         12.9         11.4         10.0          7.2
 
<CAPTION>
                                                                        CLASS IIA-5
                                          -----------------------------------------------------------------------
DISTRIBUTION DATE                           0%       100%         175%         250%         350%         500%
- ----------------------------------------  -----------------------------------------------------------------------
Initial Percentage......................    100 %        100%         100%         100%         100%         100%
April 25, 1998..........................    108          108          108          108           16            0
April 25, 1999..........................    116          116          116          116            0            0
April 25, 2000..........................    125          125          125          125            0            0
April 25, 2001..........................    135          135          135          135            0            0
April 25, 2002..........................    145          145          145          145            0            0
April 25, 2003..........................    157          157          157          157            0            0
April 25, 2004..........................    169          169          169          169            0            0
April 25, 2005..........................    182          182          182          182            0            0
April 25, 2006..........................    196          196          196          196            0            0
April 25, 2007..........................    211          211          211          211            0            0
April 25, 2008..........................    228          228          228          228            0            0
April 25, 2009..........................    245          245          245          245            0            0
April 25, 2010..........................    264          264          264          229            0            0
April 25, 2011..........................    285          285          285          189            0            0
April 25, 2012..........................    307          307          307          155            0            0
April 25, 2013..........................    331          331          331          127            0            0
April 25, 2014..........................    356          356          343          104            0            0
April 25, 2015..........................    384          384          293           84            0            0
April 25, 2016..........................    414          414          248           68            0            0
April 25, 2017..........................    446          446          209           54            0            0
April 25, 2018..........................    481          481          174           43            0            0
April 25, 2019..........................    518          487          143           33            0            0
April 25, 2020..........................    558          414          115           26            0            0
April 25, 2021..........................    602          344           91           19            0            0
April 25, 2022..........................    648          277           70           14            0            0
April 25, 2023..........................    699          214           52           10            0            0
April 25, 2024..........................    753          153           35            6            0            0
April 25, 2025..........................    590           95           21            4            0            0
April 25, 2026..........................    263           40            8            1            0            0
April 25, 2027..........................      0            0            0            0            0            0
Weighted Average Life (Years)(1)........   28.6         25.5         21.6         17.1          0.7          0.4
</TABLE>
 
- ----------------------------------
 *  Indicates an amount above zero and less than 0.5% of original principal
    balance outstanding.
 
(1) The weighted average life of any Class of Certificates is determined by (i)
    multiplying the amount of each assumed principal distribution on such Class
    of Certificates by the number of years from the date of issuance of the
    Certificates to the related Distribution Date, (ii) summing the results, and
    (iii) dividing the sum by the total amount of principal distributed on such
    Class of Certificates.
 
                                     S-108
<PAGE>
                    GROUP II LOANS - 30 YEAR MORTGAGE LOANS
             PERCENT OF INITIAL CLASS PRINCIPAL BALANCE OUTSTANDING
           AT VARIOUS PERCENTAGES OF THE BASIC PREPAYMENT ASSUMPTION
<TABLE>
<CAPTION>
                                                                          CLASS IIA-6
<S>                                       <C>          <C>          <C>          <C>          <C>          <C>
                                          ----------------------------------------------------------------------------
 
<CAPTION>
DISTRIBUTION DATE                             0%          100%         175%         250%         350%         500%
- ----------------------------------------  ----------------------------------------------------------------------------
<S>                                       <C>          <C>          <C>          <C>          <C>          <C>
Initial Percentage......................         100%         100%         100%         100%         100%         100%
April 25, 1998..........................         100          100          100          100          100          100
April 25, 1999..........................         100          100          100          100          100          100
April 25, 2000..........................         100          100          100          100          100          100
April 25, 2001..........................         100            0            0            0            0            0
April 25, 2002..........................         100            0            0            0            0            0
April 25, 2003..........................         100            0            0            0            0            0
April 25, 2004..........................         100            0            0            0            0            0
April 25, 2005..........................         100            0            0            0            0            0
April 25, 2006..........................         100            0            0            0            0            0
April 25, 2007..........................          98            0            0            0            0            0
April 25, 2008..........................          67            0            0            0            0            0
April 25, 2009..........................          33            0            0            0            0            0
April 25, 2010..........................           0            0            0            0            0            0
April 25, 2011..........................           0            0            0            0            0            0
April 25, 2012..........................           0            0            0            0            0            0
April 25, 2013..........................           0            0            0            0            0            0
April 25, 2014..........................           0            0            0            0            0            0
April 25, 2015..........................           0            0            0            0            0            0
April 25, 2016..........................           0            0            0            0            0            0
April 25, 2017..........................           0            0            0            0            0            0
April 25, 2018..........................           0            0            0            0            0            0
April 25, 2019..........................           0            0            0            0            0            0
April 25, 2020..........................           0            0            0            0            0            0
April 25, 2021..........................           0            0            0            0            0            0
April 25, 2022..........................           0            0            0            0            0            0
April 25, 2023..........................           0            0            0            0            0            0
April 25, 2024..........................           0            0            0            0            0            0
April 25, 2025..........................           0            0            0            0            0            0
April 25, 2026..........................           0            0            0            0            0            0
April 25, 2027..........................           0            0            0            0            0            0
Weighted Average Life (Years)(1)........        11.5          3.6          3.6          3.6          3.6          3.6
 
<CAPTION>
                                                                        CLASS IIA-7
<S>                                       <C>     <C>          <C>          <C>          <C>          <C>
                                          -----------------------------------------------------------------------
DISTRIBUTION DATE                           0%       100%         175%         250%         350%         500%
- ----------------------------------------  -----------------------------------------------------------------------
<S>                                       <C>     <C>          <C>          <C>          <C>          <C>
Initial Percentage......................    100 %        100%         100%         100%         100%         100%
April 25, 1998..........................    100          100          100          100          100          100
April 25, 1999..........................    100          100          100          100          100          100
April 25, 2000..........................    100          100          100          100          100          100
April 25, 2001..........................    100           93           93           93           93           93
April 25, 2002..........................    100            0            0            0            0            0
April 25, 2003..........................    100            0            0            0            0            0
April 25, 2004..........................    100            0            0            0            0            0
April 25, 2005..........................    100            0            0            0            0            0
April 25, 2006..........................    100            0            0            0            0            0
April 25, 2007..........................    100            0            0            0            0            0
April 25, 2008..........................    100            0            0            0            0            0
April 25, 2009..........................    100            0            0            0            0            0
April 25, 2010..........................     96            0            0            0            0            0
April 25, 2011..........................     64            0            0            0            0            0
April 25, 2012..........................     28            0            0            0            0            0
April 25, 2013..........................      0            0            0            0            0            0
April 25, 2014..........................      0            0            0            0            0            0
April 25, 2015..........................      0            0            0            0            0            0
April 25, 2016..........................      0            0            0            0            0            0
April 25, 2017..........................      0            0            0            0            0            0
April 25, 2018..........................      0            0            0            0            0            0
April 25, 2019..........................      0            0            0            0            0            0
April 25, 2020..........................      0            0            0            0            0            0
April 25, 2021..........................      0            0            0            0            0            0
April 25, 2022..........................      0            0            0            0            0            0
April 25, 2023..........................      0            0            0            0            0            0
April 25, 2024..........................      0            0            0            0            0            0
April 25, 2025..........................      0            0            0            0            0            0
April 25, 2026..........................      0            0            0            0            0            0
April 25, 2027..........................      0            0            0            0            0            0
Weighted Average Life (Years)(1)........   14.4          4.5          4.5          4.5          4.5          4.5
 
<CAPTION>
                                                                CLASS IIB-1, IIB-2 & IIB-3
                                          -----------------------------------------------------------------------
DISTRIBUTION DATE                           0%       100%         175%         250%         350%         500%
- ----------------------------------------  -----------------------------------------------------------------------
Initial Percentage......................    100 %        100%         100%         100%         100%         100%
April 25, 1998..........................     99           99           99           99           99           99
April 25, 1999..........................     98           98           98           98           98           98
April 25, 2000..........................     97           97           97           97           97           97
April 25, 2001..........................     96           96           96           96           96           96
April 25, 2002..........................     95           95           95           95           95           95
April 25, 2003..........................     94           92           91           89           87           84
April 25, 2004..........................     92           89           86           83           79           72
April 25, 2005..........................     91           84           79           74           67           57
April 25, 2006..........................     89           79           71           64           55           42
April 25, 2007..........................     88           72           62           53           42           29
April 25, 2008..........................     86           67           54           44           33           20
April 25, 2009..........................     84           61           48           37           25           14
April 25, 2010..........................     82           56           42           30           19            9
April 25, 2011..........................     79           51           36           25           15            6
April 25, 2012..........................     77           46           31           21           11            4
April 25, 2013..........................     74           42           27           17            9            3
April 25, 2014..........................     71           38           23           14            7            2
April 25, 2015..........................     68           34           20           11            5            1
April 25, 2016..........................     64           30           17            9            4            1
April 25, 2017..........................     60           27           14            7            3            1
April 25, 2018..........................     56           23           12            6            2            *
April 25, 2019..........................     51           20           10            4            1            *
April 25, 2020..........................     46           17            8            3            1            *
April 25, 2021..........................     41           14            6            3            1            *
April 25, 2022..........................     35           11            5            2            *            *
April 25, 2023..........................     29            9            3            1            *            *
April 25, 2024..........................     22            6            2            1            *            *
April 25, 2025..........................     15            4            1            *            *            *
April 25, 2026..........................      6            2            1            *            *            *
April 25, 2027..........................      0            0            0            0            0            0
Weighted Average Life (Years)(1)........   20.4         15.1         12.9         11.4         10.0          8.8
</TABLE>
 
- ----------------------------------
 *  Indicates an amount above zero and less than 0.5% of original principal
    balance outstanding.
 
(1) The weighted average life of any Class of Certificates is determined by (i)
    multiplying the amount of each assumed principal distribution on such Class
    of Certificates by the number of years from the date of issuance of the
    Certificates to the related Distribution Date, (ii) summing the results, and
    (iii) dividing the sum by the total amount of principal distributed on such
    Class of Certificates.
 
                                     S-109
<PAGE>
PROSPECTUS
                                  PNC MORTGAGE
                                SECURITIES CORP.
 
                       MORTGAGE PASS-THROUGH CERTIFICATES
                              (ISSUABLE IN SERIES)
                              -------------------
 
THESE CERTIFICATES DO NOT REPRESENT AN OBLIGATION OF OR INTEREST IN PNC MORTGAGE
  SECURITIES CORP. OR ANY OF ITS AFFILIATES, INCLUDING PNC BANK CORP. NEITHER
    THESE CERTIFICATES NOR THE UNDERLYING MORTGAGE LOANS ARE GUARANTEED BY
                   ANY AGENCY OR INSTRUMENTALITY OF THE UNITED STATES.
                              -------------------
 
    PNC MORTGAGE SECURITIES CORP. (THE "COMPANY") MAY SELL FROM TIME TO TIME UP
TO $3,000,000,000 AGGREGATE AMOUNT OF CERTIFICATES (THE "CERTIFICATES")
EVIDENCING UNDIVIDED INTERESTS IN ONE OR MORE TRUSTS (EACH, A "TRUST FUND") TO
BE CREATED BY THE COMPANY FROM TIME TO TIME.
 
    THE CERTIFICATES WILL BE ISSUABLE IN SERIES (EACH, A "SERIES"), EACH OF
WHICH WILL REPRESENT UNDIVIDED INTERESTS IN A SINGLE TRUST FUND, UNLESS
OTHERWISE INDICATED IN THE APPLICABLE PROSPECTUS SUPPLEMENT. THE PROPERTY OF
EACH TRUST FUND WILL CONSIST EITHER OF A POOL OF MORTGAGE LOANS (A "MORTGAGE
POOL") SECURED BY ONE-TO FOUR-FAMILY RESIDENTIAL PROPERTIES OR MULTI-FAMILY
RESIDENTIAL PROPERTIES (THE "MORTGAGE LOANS") WHICH MORTGAGE LOANS, IF SO
SPECIFIED IN THE RELATED PROSPECTUS SUPPLEMENT, MAY INCLUDE COOPERATIVE
APARTMENT LOANS ("COOPERATIVE LOANS"), AND RELATED PROPERTY AND INTERESTS,
CONVEYED TO THE TRUST FUND BY THE COMPANY, OR OF CERTIFICATES WHICH IN TURN
EVIDENCE OWNERSHIP OF A MORTGAGE POOL AND RELATED PROPERTY. UNLESS OTHERWISE
INDICATED IN THE RELATED PROSPECTUS SUPPLEMENT, EACH POOL WILL CONSIST ENTIRELY
OF FIXED-RATE FIRST-LIEN MORTGAGE LOANS OR ENTIRELY OF ADJUSTABLE-RATE
FIRST-LIEN MORTGAGE LOANS ACQUIRED BY THE COMPANY FROM ONE OR MORE QUALIFIED
SELLERS. INFORMATION REGARDING EACH SERIES OF CERTIFICATES, INCLUDING THE RATE
OF INTEREST BORNE BY THE CERTIFICATES (THE "REMITTANCE RATE") FOR SUCH SERIES,
AS WELL AS INFORMATION REGARDING THE SIZE, COMPOSITION AND OTHER CHARACTERISTICS
OF THE POOL RELATING TO SUCH SERIES, WILL BE FURNISHED IN A PROSPECTUS
SUPPLEMENT AT THE TIME SUCH SERIES IS OFFERED. IF INDICATED IN THE APPLICABLE
PROSPECTUS SUPPLEMENT, CERTIFICATES OF A SERIES MAY BE DIVIDED INTO SEVERAL
CLASSES (EACH, A "CLASS"), WHICH EACH MAY BEAR DIFFERENT RATES OF INTEREST, AND
THE RIGHTS OF THE HOLDERS OF CERTAIN CLASSES MAY BE SUBORDINATED TO THOSE OF
OTHER CLASSES, AS SPECIFIED IN THE APPLICABLE PROSPECTUS SUPPLEMENT.
 
    THE COMPANY WILL, WITH RESPECT TO EACH SERIES OF CERTIFICATES, ELECT TO HAVE
THE RELATED MORTGAGE POOL TREATED AS A REAL ESTATE MORTGAGE INVESTMENT CONDUIT
(A "REMIC") UNDER APPLICABLE PROVISIONS OF THE INTERNAL REVENUE CODE. SEE
"CERTAIN FEDERAL INCOME TAX CONSEQUENCES".
 
    EXCEPT FOR CERTAIN REPRESENTATIONS AND WARRANTIES, AND EXCEPT AS OTHERWISE
STATED IN THE RELATED PROSPECTUS SUPPLEMENT, THE COMPANY'S SOLE OBLIGATIONS WITH
RESPECT TO A SERIES OF THE CERTIFICATES ARE ITS CONTRACTUAL SERVICING AND/OR
ADMINISTRATIVE RESPONSIBILITIES AND ITS OBLIGATION (UNLESS OTHERWISE SPECIFIED
IN THE APPLICABLE PROSPECTUS SUPPLEMENT), IN THE EVENT OF PAYMENT DELINQUENCIES
ON MORTGAGE LOANS, TO MAKE CASH ADVANCES WITH RESPECT THERETO IF IT DEEMS SUCH
ADVANCES TO BE RECOVERABLE FROM THE PROCEEDS OF ANY APPLICABLE CREDIT
ENHANCEMENT INSTRUMENTS, LIQUIDATION PROCEEDS OR OTHERWISE.
 
    SEE "RISK FACTORS" IMMEDIATELY FOLLOWING "SUMMARY OF PROSPECTUS" HEREIN FOR
A DISCUSSION OF CERTAIN FACTORS THAT SHOULD BE CONSIDERED BEFORE PURCHASING
CERTIFICATES OF ANY SERIES.
                               -----------------
 
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
  EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE NOR HAS ANY
    SUCH COMMISSION PASSED UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS.
           ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.
                              -------------------
 
    OFFERS OF THE CERTIFICATES MAY BE MADE THROUGH ONE OR MORE DIFFERENT
METHODS, INCLUDING OFFERINGS THROUGH UNDERWRITERS, AS MORE FULLY DESCRIBED UNDER
"METHODS OF DISTRIBUTION". THE CERTIFICATES FOR EACH MORTGAGE POOL ARE OFFERED
WHEN, AS AND IF ISSUED, SUBJECT TO PRIOR SALE OR WITHDRAWAL, CANCELLATION OR
MODIFICATION OF THE OFFER WITHOUT NOTICE.
 
    THIS PROSPECTUS MAY ALSO BE USED IN CONNECTION WITH RESALES OF CERTIFICATES
BY CERTAIN PURCHASERS THEREOF, INCLUDING DEALERS, WHO ARE OR MAY BE DEEMED TO BE
"UNDERWRITERS" WITHIN THE MEANING OF THE SECURITIES ACT OF 1933. SEE "METHODS OF
DISTRIBUTION" HEREIN. RE-OFFERS AND SALES OF CERTIFICATES BY PURCHASERS THEREOF
ARE EXPECTED TO BE MADE AT THEN PREVAILING MARKET PRICES, ALTHOUGH THERE CAN BE
NO ASSURANCE THAT A SECONDARY MARKET FOR ANY SERIES OF CERTIFICATES WILL
DEVELOP.
 
    RETAIN THIS PROSPECTUS FOR FUTURE REFERENCE.
 
    THIS PROSPECTUS MAY NOT BE USED TO CONSUMMATE SALES OF CERTIFICATES UNLESS
ACCOMPANIED BY A PROSPECTUS SUPPLEMENT.
 
NOVEMBER 21, 1996
<PAGE>
                               TABLE OF CONTENTS
 
<TABLE>
<CAPTION>
CAPTION                                                                     PAGE
- --------------------------------------------------------------------------  ----
<S>                                                                         <C>
Summary of Prospectus.....................................................    3
Risk Factors..............................................................    9
The Mortgage Pools........................................................   10
Use of Proceeds...........................................................   14
Yield Considerations......................................................   14
Maturity, Average Life and Prepayment Assumptions.........................   16
The Company...............................................................   17
Description of Certificates...............................................   20
Primary Insurance, FHA Mortgage Insurance, VA Mortgage Guaranty, Hazard
 Insurance; Claims Thereunder.............................................   39
Description of Credit Enhancements........................................   44
Certain Legal Aspects of the Mortgage Loans...............................   52
ERISA Considerations......................................................   59
Certain Federal Income Tax Consequences...................................   62
Methods of Distribution...................................................   78
Transferability of Certificates...........................................   78
Legal Matters.............................................................   79
Financial Information.....................................................   79
Additional Information....................................................   79
Glossary..................................................................   80
</TABLE>
 
    UNTIL 90 DAYS AFTER THE DATE OF EACH SUPPLEMENT TO THIS PROSPECTUS, ALL
DEALERS EFFECTING TRANSACTIONS IN THE REGISTERED SECURITIES COVERED BY SUCH
SUPPLEMENT, WHETHER OR NOT PARTICIPATING IN THE DISTRIBUTION THEREOF, MAY BE
REQUIRED TO DELIVER SUCH SUPPLEMENT AND THIS PROSPECTUS. THIS IS IN ADDITION TO
THE OBLIGATION OF DEALERS TO DELIVER A SUPPLEMENT AND PROSPECTUS WHEN ACTING AS
UNDERWRITERS OF SECURITIES COVERED BY SUCH SUPPLEMENT AND WITH RESPECT TO THEIR
UNSOLD ALLOTMENTS OR SUBSCRIPTIONS.
 
    NO PERSON HAS BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY
REPRESENTATION OTHER THAN THOSE CONTAINED IN THIS PROSPECTUS AND EACH SUPPLEMENT
TO THIS PROSPECTUS AND, IF GIVEN OR MADE, SUCH INFORMATION OR REPRESENTATION
MUST NOT BE RELIED UPON. THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL OR
A SOLICITATION OF AN OFFER TO BUY ANY SECURITIES OTHER THAN THE CERTIFICATES
OFFERED HEREBY, NOR AN OFFER OF THE CERTIFICATES TO ANY PERSON IN ANY STATE OR
OTHER JURISDICTION IN WHICH SUCH OFFER WOULD BE UNLAWFUL. THE DELIVERY OF THIS
PROSPECTUS AT ANY TIME DOES NOT IMPLY THAT INFORMATION HEREIN IS CORRECT AS OF
ANY TIME SUBSEQUENT TO ITS DATE; HOWEVER, IF ANY MATERIAL CHANGE OCCURS WHILE
THIS PROSPECTUS IS REQUIRED BY LAW TO BE DELIVERED, THIS PROSPECTUS WILL BE
AMENDED OR SUPPLEMENTED ACCORDINGLY.
 
               INCORPORATION OF CERTAIN INFORMATION BY REFERENCE
 
    There are incorporated herein by reference all documents and reports filed
or caused to be filed by the Company with respect to a Series pursuant to
Section 13(a), Section 13(c), Section 14 or Section 15(d) of the Securities
Exchange Act of 1934, prior to the termination of an offering of Certificates
evidencing interests therein. Upon request, the Company will provide or cause to
be provided without charge to each person to whom this Prospectus is delivered
in connection with the offering of one or more Classes of Certificates, a list
identifying all filings with respect to a Series pursuant to Section 13(a),
Section 13(c), Section 14 or Section 15(d) of the Securities Exchange Act of
1934, since the Company's last fiscal year covered by its annual report on Form
10-K, if any, and a copy of any or all documents or reports incorporated herein
by reference, in each case to the extent such documents or reports relate to one
or more such Classes of such Certificates, other than the exhibits to such
documents (unless such exhibits are specifically incorporated by reference in
such documents). Requests to the Company should be directed to: PNC Mortgage
Securities Corp., 75 North Fairway Dr., Vernon Hills, IL 60061, telephone number
(847) 549-6500, Attn: Legal Department.
 
                                       2
<PAGE>
                             SUMMARY OF PROSPECTUS
 
    THE FOLLOWING IS A SUMMARY OF CERTAIN PERTINENT INFORMATION AND IS QUALIFIED
IN ITS ENTIRETY BY REFERENCE TO THE DETAILED INFORMATION APPEARING ELSEWHERE IN
THIS PROSPECTUS, AND BY REFERENCE TO INFORMATION WITH RESPECT TO EACH MORTGAGE
POOL AND SERIES OF CERTIFICATES CONTAINED IN THE SUPPLEMENT TO THIS PROSPECTUS
TO BE PREPARED IN CONNECTION WITH SUCH SERIES.
 
<TABLE>
<S>                           <C>
Title of Certificates.......  Mortgage Pass-Through Certificates, issuable in
                              Series and in one or more Classes of each Series
                              (the "Certificates").
 
Depositor...................  PNC Mortgage Securities Corp. (the "Company"), an
                              indirect subsidiary of PNC Bank Corp.
 
Description of
  Certificates..............  Each Certificate will represent an undivided
                              interest in one of a number of trusts to be
                              created by the Company from time to time. The
                              property of each trust fund (a "Trust Fund") will
                              consist either of a pool (a "Mortgage Pool") of
                              mortgage loans secured by one-to four-family
                              residential properties or multi-family residential
                              properties (the "Mortgage Loans") which Mortgage
                              Loans, if so specified in the related Prospectus
                              Supplement, may include cooperative apartment
                              loans ("Cooperative Loans"), and related property
                              and interests, conveyed to such Trust Fund by the
                              Company, or of certificates which in turn
                              represent ownership of a Mortgage Pool and related
                              property and interests. Unless otherwise specified
                              in the applicable Prospectus Supplement, each
                              Certificate will represent an interest in all the
                              principal and in interest up to a specified rate
                              on the Mortgage Loans in such Mortgage Pool. If so
                              specified in the Prospectus Supplement applicable
                              to any Series, Certificates may be issued in
                              several Classes, which may pay interest at
                              different rates, may represent different
                              allocations of the right to receive principal and
                              interest, and certain of which may be subordinated
                              to others. Any such Class of Certificates may
                              provide for payments of principal only or interest
                              only or for disproportionate payments of principal
                              and interest. See "Description of Certificates".
                              The related Prospectus Supplement or Current
                              Report on Form 8-K described below will set forth
                              the actual undivided interest in a Mortgage Pool,
                              or entitlement to principal and/or interest,
                              represented by each Certificate (and, if
                              applicable, describe the manner in which such
                              undivided interest may change from time to time).
 
                              The Certificates will be offered in fully
                              registered form only. If specified in the
                              applicable Prospectus Supplement, one or more
                              Classes of Certificates for any Series may be
                              transferable only on the books of The Depository
                              Trust Company or another depository identified in
                              such Prospectus Supplement. The Certificates of a
                              particular Series or Class may or may not be rated
                              by one or more nationally recognized rating
                              organizations. Neither the Certificates, the
                              underlying Mortgage Loans nor certificates will be
                              guaranteed by the Company, PNC Bank Corp. or any
                              other affiliate of the Company and, unless
                              otherwise specified in the applicable Prospectus
                              Supplement, neither the Certificates, the
                              underlying Mortgage Loans nor certificates will be
                              insured or guaranteed by any governmental agency.
                              Additional
</TABLE>
 
                                       3
<PAGE>
 
<TABLE>
<S>                           <C>
                              information about the Mortgage Pool relating to a
                              Series of Certificates may be set forth in a
                              Current Report on Form 8-K that will be filed with
                              the Securities and Exchange Commission within 15
                              days after the issuance of such Certificates. If
                              so indicated in the applicable Prospectus
                              Supplement, a Series of Certificates may include
                              one or more Classes of Certificates (which may be
                              sold in one or more private offerings or may be
                              offered pursuant to this Prospectus) representing
                              subordinated interests in the Mortgage Pool,
                              undivided interests in a portion of the interest
                              paid on the Mortgage Loans in the related Mortgage
                              Pool or such other interests as may be described
                              therein.
 
Sellers.....................  Mortgage Loans will be purchased from qualified
                              originators or entities that have purchased or
                              otherwise acquired the Mortgage Loans from
                              qualified originators ("Sellers"), as described
                              herein.
 
Servicing and
  Administration............  Generally, the Company will be responsible for the
                              servicing and administration of the Mortgage Loans
                              (in such capacity, the "Master Servicer") and the
                              Sellers will perform certain servicing functions
                              with respect to the Mortgage Loans (in such
                              capacity, "Seller/Servicers"). If so specified in
                              the applicable Prospectus Supplement, however, (i)
                              the servicing of the Mortgage Loans will be
                              performed by the Seller which sold the Mortgage
                              Loans to the Company for inclusion in the Trust
                              Fund, or by a qualified servicer selected by the
                              Company (either entity acting in such capacity,
                              the "Servicer"), (ii) there will not be a Master
                              Servicer and (iii) the Company will calculate
                              amounts distributable to the Certificateholders,
                              prepare tax returns on behalf of the Trust Fund
                              and provide certain other administrative services
                              specified in the Pooling Agreement (in such
                              capacity, the "Certificate Administrator").
 
Interest....................  Except as otherwise specified in the applicable
                              Prospectus Supplement, interest payments will be
                              passed through on the 25th day (or if such day is
                              not a business day, the business day immediately
                              following such 25th day) of each month or such
                              other date as specified in the applicable
                              Prospectus Supplement (the "Distribution Date") at
                              the interest rate (the "Remittance Rate")
                              applicable to each Class of Certificates,
                              commencing with the month following the month of
                              initial issuance of such Certificates. See
                              "Maturity, Average Life and Prepayment
                              Assumptions", "Yield Considerations" and
                              "Description of Certificates".
 
Principal (including
  Principal Prepayments)....  Except as otherwise specified in the applicable
                              Prospectus Supplement, principal payments will be
                              passed through on each Distribution Date,
                              commencing with the month following the month of
                              initial issuance of each Series of Certificates.
                              See "Maturity, Average Life and Prepayment
                              Assumptions", "Yield Considerations" and
                              "Description of Certificates".
 
Advances....................  With respect to Series of Certificates as to which
                              the Company will act as Master Servicer and except
                              as otherwise specified in
</TABLE>
 
                                       4
<PAGE>
 
<TABLE>
<S>                           <C>
                              the applicable Prospectus Supplement, the Master
                              Servicer will be obligated to make advances of its
                              own funds in order to cover deficiencies in
                              amounts distributable to Certificateholders
                              resulting from Mortgagor delinquencies only, to
                              the extent the Master Servicer determines such
                              advances are recoverable from future payments or
                              collections on the Mortgage Loans, amounts
                              available as a result of any subordination feature
                              or from applicable credit enhancements. Similarly,
                              with respect to Series of Certificates as to which
                              the Company will not act as Master Servicer and
                              the servicing of the Mortgage Loans will be
                              performed by the Servicer, the Servicer, except as
                              otherwise specified in the applicable prospectus
                              supplement, will be obligated to make advances of
                              its own funds in order to cover deficiencies in
                              amounts distributable to Certificateholders only
                              to the extent the Servicer determines such
                              advances are recoverable from future payments or
                              collections on the Mortgage Loans, amounts
                              available as a result of any subordination in
                              right of payment of one or more Classes of
                              Certificates to such rights of holders of other
                              Classes of Certificates or from applicable credit
                              enhancements. See "Description of
                              Certificates--Advances".
 
The Mortgage Loans..........  Each Mortgage Pool will have an aggregate
                              principal balance of at least $5,000,000 and will
                              consist of one or more of the following types of
                              Mortgage Loans with various original terms:
</TABLE>
 
<TABLE>
<S>                           <C>   <C>
                               (1)  fixed-rate, fully amortizing Mortgage Loans
                                    providing for level monthly payments of
                                    principal and interest;
 
                               (2)  adjustable-rate Mortgage Loans ("ARMs" or
                                    "ARM Loans"), which may include graduated
                                    payment Mortgage Loans and other Mortgage
                                    Loans providing for negative amortization;
 
                               (3)  Mortgage Loans, with either fixed or
                                    adjustable rates, that do not provide for
                                    level monthly payments of principal and
                                    interest and/or do not provide for
                                    amortization in full by their maturity
                                    dates;
 
                               (4)  fixed-rate Mortgage Loans that do not
                                    provide for amortization in full by their
                                    maturity dates and which may at the end of
                                    their terms be converted by the Mortgagors
                                    to fully-amortizing ARM Loans, provided that
                                    certain conditions are met; and
 
                               (5)  any other type of Mortgage Loan, as
                                    described in the applicable Prospectus
                                    Supplement.
</TABLE>
 
<TABLE>
<S>                           <C>
                              If provided for in the applicable Prospectus
                              Supplement, a Mortgage Pool may contain Mortgage
                              Loans subject to buy- down plans ("Buydown
                              Loans"). See "The Mortgage Pools".
 
Primary Insurance
  Policies..................  To the extent specified in the applicable
                              Prospectus Supplement, each Mortgage Loan having a
                              loan-to-value ratio at origination and at the
                              applicable Cut-Off Date (as defined herein) above
                              80% (or another specified level) will be covered
</TABLE>
 
                                       5
<PAGE>
 
<TABLE>
<S>                           <C>
                              by a primary mortgage insurance policy (a "Primary
                              Insurance Policy") insuring against default by the
                              Mortgagor with respect to all or a specified
                              portion of the principal amount thereof, until the
                              principal balance of such Mortgage Loan is reduced
                              below 80% of the then current appraised value of
                              the Mortgaged Property or the principal balance of
                              the Mortgage Loan at origination, as applicable.
                              See "The Mortgage Pools" and "Primary Mortgage
                              Insurance, FHA Mortgage Insurance, VA Mortgage
                              Guaranty, Hazard Insurance; Claims Thereunder".
 
Credit Enhancements.........  The Company or the Servicer, as applicable, may
                              obtain for certain Mortgage Pools a mortgage pool
                              insurance policy (a "Mortgage Pool Insurance
                              Policy"), limited in scope, covering defaults on
                              the Mortgage Loans in such Mortgage Pool that are
                              not covered as to their entire outstanding
                              principal balance by insurance coverage provided
                              by the Federal Housing Authority or guarantees
                              issued by the Department of Veterans Affairs.
 
                              The Company or the Servicer, as applicable, may
                              also obtain for certain Mortgage Pools a fraud
                              bond (a "Fraud Bond"), limited in scope, insuring
                              Certificateholders against losses on any Mortgage
                              Loan which result in an exclusion from, denial of,
                              or defense to coverage under a Primary Insurance
                              Policy or, if applicable, a Mortgage Pool
                              Insurance Policy, because of circumstances
                              involving fraudulent conduct or negligence by the
                              Seller, a Seller/Servicer, the Servicer or the
                              related mortgagor (the "Mortgagor").
 
                              In addition, the Company or the Servicer, as
                              applicable, may obtain for certain Mortgage Pools
                              a bankruptcy bond (a "Bankruptcy Bond"), limited
                              in scope, insuring against losses resulting from
                              the bankruptcy of a Mortgagor under a Mortgage
                              Loan contained in a Mortgage Pool.
 
                              All of the Mortgage Loans (other than Cooperative
                              Loans and Mortgage Loans secured by condominium
                              apartments) will be covered by standard hazard
                              insurance policies insuring against losses due to
                              various causes, including fire, lightning and
                              windstorm. For some Series of Certificates,
                              certain other physical risks which are not
                              otherwise insured against (including earthquakes
                              in some geographical regions, mud flows and
                              floods) will be covered by a special hazard
                              insurance policy (a "Special Hazard Insurance
                              Policy") to be obtained with respect to the
                              Mortgage Pool.
 
                              In lieu of obtaining one or more of the credit
                              enhancements described above, the Seller, the
                              Company or the Servicer, as applicable, may
                              establish a reserve fund (a "Reserve Fund") and/or
                              obtain a letter of credit (a "Letter of Credit"),
                              either of which would provide coverage
                              substantially similar to the credit enhancement or
                              enhancements it replaces. Any losses not covered
                              by any of these credit enhancements will not be
                              insured against and will therefore be borne by
                              Certificateholders for such Series. See "The
                              Mortgage Pools" and "Description of Credit
                              Enhancements".
</TABLE>
 
                                       6
<PAGE>
 
<TABLE>
<S>                           <C>
                              In addition to the credit enhancements described
                              above, the Company or the Servicer, as applicable,
                              may obtain or provide for other credit
                              enhancements for a Series of Certificates which
                              provide for coverage of certain risks of default
                              or losses, such as, but not limited to,
                              certificate insurance policies issued by insurers
                              acceptable to each rating agency rating the
                              Certificates, insuring to holders of the
                              Certificates the payment of amounts due in
                              accordance with the terms of the Certificates, or
                              other arrangements acceptable to each rating
                              agency rating the Certificates. Coverage of
                              certain risks of default or loss may also be
                              provided to a particular Class or Classes of
                              Certificates by the subordination in right of
                              payment of one or more Classes of Certificates of
                              the same Series to the right of holders of such
                              Class or Classes of Certificates to receive
                              payments.
 
                              The Prospectus Supplement for each Series will
                              indicate whether such Series or the Mortgage Loans
                              contained therein are covered by various credit
                              enhancements, indicating the nature, amount and
                              extent of such coverage.
 
Private Certificates and
  Agency Certificates.......  If specified in the related Prospectus Supplement,
                              a Trust Fund may include private mortgage
                              pass-through certificates ("Private Certificates")
                              or certificates issued by the Federal Home Loan
                              Mortgage Corporation ("FHLMC"), the Federal
                              National Mortgage Association ("FNMA") or the
                              Government National Mortgage Association ("GNMA")
                              (collectively, "Agency Certificates"). Any Private
                              Certificates or Agency Certificates will be
                              described in the related Prospectus Supplement.
 
Tax Status..................  For Federal income tax purposes, the
                              Certificateholders of a Series will be considered
                              to own "regular interests" or "residual interests"
                              in a REMIC. Holders of Certificates designated in
                              the applicable Prospectus Supplement as "regular
                              interests" will be treated as holders of debt of
                              the REMIC for federal income tax purposes. Such
                              Certificateholders must include in income interest
                              due and original issue discount on their
                              Certificates using the accrual method of
                              accounting, regardless of their usual methods of
                              accounting. Holders of Certificates designated in
                              the applicable Prospectus Supplement as "residual
                              interests" will be taxable on their allocable
                              share of the taxable income of the REMIC
                              regardless of the cash distributable on such
                              interests. See "Certain Federal Income Tax
                              Consequences--Taxation of Owners of REMIC Residual
                              Certificates".
 
                              With certain exceptions described herein,
                              Certificates held by a "domestic building and loan
                              association" will be considered to represent
                              "loans secured by an interest in real property"
                              within the meaning of Section 7701(a)(19)(C)(v) of
                              the Internal Revenue Code of 1986, as amended (the
                              "Code"), and to represent "qualifying real
                              property loans" within the meaning of Section
                              593(d) of the Code.
</TABLE>
 
                                       7
<PAGE>
 
<TABLE>
<S>                           <C>
                              See "Certain Federal Income Tax Consequences".
 
Optional Termination........  For each Series of Certificates, the Company will
                              have the option to repurchase the related Mortgage
                              Loans or certificates, as the case may be, and
                              thereby effect the early retirement of such Series
                              at any time after the principal balances of the
                              Mortgage Loans or certificates aggregate less than
                              the percentage specified in the related Prospectus
                              Supplement of the aggregate principal balance of
                              the Mortgage Loans in such Mortgage Pool or the
                              certificates as of the first day of the month in
                              which such Certificates were issued or such other
                              day as may be specified in the applicable
                              Prospectus Supplement (the "Cut-Off Date"). The
                              amount distributable to Certificateholders in
                              connection with any such repurchase will also be
                              set forth in the applicable Prospectus Supplement.
 
Investment Considerations...  Potential investors should be aware that (a) any
                              decline in the value of a property securing a
                              Mortgage Loan in a Mortgage Pool may result in a
                              loss to Certificateholders if the related
                              Mortgagor defaults and the loss is not covered by
                              the credit enhancements provided for such Mortgage
                              Loan or Mortgage Pool and (b) any hazard loss not
                              covered by the standard hazard insurance policy or
                              any applicable Special Hazard Insurance Policy or
                              comparable credit enhancement covering a defaulted
                              Mortgage Loan may result in a loss to
                              Certificateholders.
 
                              Prepayments of Mortgage Loans, or early
                              liquidations of Mortgage Loans by foreclosure or
                              otherwise (whether or not a loss is incurred) may,
                              in certain circumstances, increase or, in certain
                              circumstances, decrease Certificateholders' yield
                              on the Certificates. See "Yield Considerations"
                              and "Maturity, Average Life and Prepayment
                              Assumptions".
 
                              There is no assurance that a secondary market will
                              exist for any Series of the Certificates.
 
                              See "Risk Factors" herein.
 
ERISA Limitations...........  A fiduciary of any employee benefit plan subject
                              to the Employee Retirement Income Security Act of
                              1974, as amended ("ERISA"), or Section 4975 of the
                              Code (and any person which proposes to cause any
                              such plan to acquire Certificates) should
                              carefully review with its own legal advisors
                              whether the purchase or holding of Certificates
                              could give rise to a transaction prohibited or
                              otherwise impermissible under ERISA or the Code.
                              See "ERISA Considerations".
</TABLE>
 
                                       8
<PAGE>
                                  RISK FACTORS
 
    Investors should consider, among other things, the following factors in
connection with the purchase of the Certificates:
 
    LIMITED LIQUIDITY.  There can be no assurance that a secondary market for
the Certificates of any Series will develop or, if it does develop, that it will
provide Certificateholders with liquidity of investment or that it will continue
for the life of the Certificates of any Series. The Prospectus Supplement for
any Series of Certificates may indicate that an underwriter specified therein
intends to establish a secondary market in such Certificates. However, no
underwriter will be obligated to do so and offerings may be effected hereunder
without participation by any underwriter. The Certificates will not be listed on
any securities exchange.
 
    LIMITED OBLIGATIONS.  The Certificates will not represent an interest in or
obligation of the Company, PNC Bank Corp. or any of their affiliates. The
obligations of the Company with respect to the Certificates or the Mortgage
Loans will be limited to any representations and warranties made by the Company
in, as well as any servicing and/or administrative obligations under, the
Pooling Agreement (as defined herein) for each Series of Certificates. Unless
otherwise specified in the applicable Prospectus Supplement, these obligations,
for Series of Certificates as to which the Company will act as Master Servicer,
will consist primarily of the obligation under certain circumstances to
repurchase Mortgage Loans as to which there has been a breach of representations
and warranties which materially and adversely affects the interests of the
Certificateholders in a Mortgage Loan or to cure such breach. In addition,
unless otherwise specified in the applicable Prospectus Supplement, the Master
Servicer will have a limited obligation to make certain advances (to the extent
not previously advanced by the Seller/Servicers) in the event of delinquencies
on the Mortgage Loans, but only to the extent deemed recoverable. Except as so
described in the related Prospectus Supplement, neither the Certificates, the
underlying Mortgage Loans nor Certificateholders will be guaranteed or insured
by any governmental agency or instrumentality, or by the Company or any of its
affiliates. Proceeds of the assets included in the related Trust Fund for each
Series of Certificates (including the Mortgage Loans and any form of credit
enhancement) will be the sole source of payments on the Certificates, and there
will be no recourse to the Company or any other entity in the event that such
proceeds are insufficient or otherwise unavailable to make all payments provided
for under the Certificates.
 
    LIMITATIONS, REDUCTION AND SUBSTITUTION OF CREDIT ENHANCEMENT.  With respect
to each Series of Certificates, credit enhancement may be provided in limited
amounts to cover certain types of losses on the underlying Mortgage Loans.
Credit enhancement will be provided in one or more of the forms referred to
herein, including, but not limited to: subordination of other Classes of
Certificates of the same Series; a Letter of Credit; a Mortgage Pool Insurance
Policy; a Special Hazard Insurance Policy; a Fraud Bond; a Bankruptcy Bond; a
Reserve Fund; and any combination thereof. See "Description of Credit
Enhancements" herein. Regardless of the form of credit enhancement provided, the
amount of coverage will be limited in amount and in most cases will be subject
to periodic reduction in accordance with a schedule or formula. Furthermore,
such credit enhancements may provide only very limited coverage as to certain
types of losses, and may provide no coverage as to certain other types of
losses. All or a portion of the credit enhancement for any series of
Certificates will generally be permitted to be reduced, terminated or
substituted for, if each applicable rating agency indicates that the then
current rating thereof will not be adversely affected. See "Description of
Credit Enhancements".
 
    RISKS OF THE MORTGAGE LOANS.  An investment in securities such as the
Certificates which generally represent interests in mortgage loans may be
affected by, among other things, a decline in real estate values and changes in
the related Mortgagors' financial condition. No assurance can be given that the
values of the Mortgaged Properties (as defined herein) have remained or will
remain at their levels on the dates of origination of the related Mortgage
Loans. If the residential real estate market should experience an overall
decline in property values such that the outstanding balances of the Mortgage
Loans, and any secondary financing on the Mortgaged Properties, in a particular
Mortgage Pool become equal to or greater than the value of the Mortgaged
Properties, the actual rates of delinquencies, foreclosures and losses could be
higher than those now generally experienced in the mortgage lending industry. In
addition, in the case of the Mortgage Loans that are subject to negative
amortization, the principal balances of such Mortgage Loans could be increased
to amounts equal to or
 
                                       9
<PAGE>
in excess of the values of the underlying Mortgaged Properties, thereby
increasing the likelihood of default. To the extent that such losses are not
covered by the applicable credit enhancement, holders of Certificates of the
Series evidencing interests in the related Mortgage Pool will bear all risk of
loss resulting from default by Mortgagors and will have to look primarily to the
value of the Mortgaged Properties for recovery of the outstanding principal and
unpaid interest on the defaulted Mortgage Loans. Certain of the types of loans
which may be included in the Mortgage Pools may involve additional uncertainties
not present in traditional types of loans. For example, certain of the Mortgage
Loans may provide for escalating or variable payments by the Mortgagor, as to
which the Mortgagor is generally qualified on the basis of the initial payment
amount. In some instances the Mortgagors' income may not be sufficient to enable
them to continue to make their loan payments as such payments increase and thus
the likelihood of default will increase. In addition to the foregoing, certain
geographic regions of the United States from time to time will experience weaker
regional economic conditions and housing markets and, consequently, will
experience higher rates of loss and delinquency on mortgage loans generally. The
Mortgage Loans underlying certain Series of Certificates may be concentrated in
these regions, and such concentration may present risk considerations in
addition to those generally present for similar mortgage-backed securities
without such concentration.
 
    YIELD AND PREPAYMENT CONSIDERATIONS.  The yield to maturity of the
Certificates of each Series will depend on the rate of principal payment
(including prepayments, liquidations due to defaults and repurchases) on the
Mortgage Loans and the price paid by Certificateholders. Such yield to maturity
may be adversely affected by a higher or lower than anticipated rate of
prepayments on the related Mortgage Loans. The yield to maturity on Certificates
entitling the holders thereof primarily or exclusively to payments of interest
on the Mortgage Loans will be extremely sensitive to the rate of prepayments on
the related Mortgage Loans. In addition, the yield on certain other types of
Classes of Certificates may be relatively more sensitive to the rate of
prepayment on the related Mortgage Loans than other Classes of Certificates.
Prepayments are influenced by a number of factors, including prevailing mortgage
market interest rates, local and regional economic conditions and homeowner
mobility. See "Yield Considerations" and "Maturity, Average Life and Prepayment
Assumptions".
 
                              THE MORTGAGE POOLS*
 
GENERAL
 
    Unless otherwise indicated in the applicable Prospectus Supplement, each
Mortgage Pool will consist entirely of either fixed- or adjustable-rate mortgage
loans (the "Mortgage Loans") evidenced by promissory notes (the "Mortgage
Notes") secured by first mortgages, deeds of trust or security deeds (the
"Mortgages") on one- to four-family residential properties or multi-family
residential properties (the "Mortgaged Properties"). The types of Mortgaged
Properties securing the Mortgage Loans in each Mortgage Pool may include (a)
owner occupied, (i) attached or detached single-family residences, including
residences in planned unit developments, (ii) two- to four-family primary
residences and (iii) condominiums or other attached dwelling units, (b)
second/vacation homes and nonowner occupied residences, and (c) such other types
of homes or dwellings as are set forth in the related Prospectus Supplement. If
specified in the applicable Prospectus Supplement, a Mortgage Pool may contain
cooperative apartment loans ("Cooperative Loans") evidenced by promissory notes
("Cooperative Notes") secured by security interests in shares issued by private
cooperative housing corporations (each, a "Cooperative") and in the related
proprietary leases or occupancy agreements granting exclusive rights to occupy
specific dwelling units in the related buildings. As used herein, unless the
context indicates otherwise, "Mortgage Loans" includes Cooperative Loans,
"Mortgaged Properties" includes shares in the related Cooperative and the
related proprietary leases or occupancy agreements securing Cooperative Notes,
"Mortgage Notes" includes Cooperative Notes and "Mortgages" includes a security
agreement with respect to a Cooperative Note.
 
- --------------
* Whenever in this Prospectus the terms "Mortgage Pool", "Certificates" and
"Trust Fund" are used, those terms apply, unless the context indicates
otherwise, to one specific Mortgage Pool, to the Series of Certificates
representing undivided interests in the related Trust Fund and to the related
Trust Fund, respectively. Similarly, the term "Remittance Rate" will refer to
the rate of interest borne by the Certificates of one specific Series (or borne
by one Class of Certificates of one specific Series).
 
                                       10
<PAGE>
    The Mortgage Loans to be purchased by the Company for inclusion in a
Mortgage Pool will be screened and underwritten in accordance with the standards
set forth herein under "The Company-- Mortgage Purchase Program" and "--Credit,
Appraisal and Underwriting Standards". The Mortgage Loans in each Mortgage Pool
will be originated by or purchased from lending institutions which meet the
requirements set forth under "The Company--Mortgage Purchase Program" (such
institutions, "Sellers"). Generally, the Company will be responsible for the
servicing and administration of the Mortgage Loans and the Sellers will perform
certain servicing functions with respect to the Mortgage Loans (in such
capacity, "Seller/Servicers"), which term includes related servicing
corporations, agents and replacement servicers designated by the Company. If so
specified in the applicable Prospectus Supplement, however, (i) the servicing of
the Mortgage Loans will be performed by the Seller which sold the Mortgage Loans
to the Company for inclusion in the Trust Fund, or by a qualified servicer
selected by the Company (either entity acting in such capacity, the "Servicer"),
(ii) there will not be a Master Servicer and (iii) the Company will calculate
amounts distributable to the Certificateholders, prepare tax returns on behalf
of the Trust Fund and provide certain other administrative services specified in
the Pooling Agreement (in such capacity, the "Certificate Administrator"). The
Servicer and the Certificate Administrator may perform their respective
servicing and administrative responsibilities through agents or independent
contractors, but shall not thereby be released from any of their obligations
under the Pooling Agreement. See "Description of Certificates--Servicing". The
applicable Prospectus Supplement will set forth information respecting the
number and principal amount of Mortgage Loans which were originated for the
purpose of (a) purchasing and (b) refinancing the related Mortgaged Properties.
 
    To the extent specified in the applicable Prospectus Supplement, Mortgage
Loans with loan-to-value ratios and/or principal balances exceeding certain
limits will be covered partially by Primary Insurance Policies. A Mortgage Pool
may include Mortgage Loans insured by the Federal Housing Administration ("FHA")
or guaranteed by the Department of Veterans Affairs ("VA"), which loans will be
covered by FHA insurance policies ("FHA Insurance Policies") and VA guaranties
("VA Guaranties"), respectively. Mortgage Loans guaranteed by the VA ("VA
Loans") may also be covered by supplemental Primary Insurance Policies. In
addition, if specified in the applicable Prospectus Supplement, the Company, the
Seller or the Servicer, as applicable, may obtain or establish one or more
credit enhancements for a Mortgage Pool. Any such credit enhancement will be
described in the applicable Prospectus Supplement. Such credit enhancements may
be limited to one or more Classes of Certificates and may include, but will not
necessarily be limited to, any of the following: a Mortgage Pool Insurance
Policy, a Special Hazard Insurance Policy, a Fraud Bond, a Bankruptcy Bond, a
Letter of Credit, a Reserve Fund, a certificate insurance policy, or any
combination of the foregoing. Coverage of certain risks of default or loss may
also be provided to a particular Class or Classes of Certificates by the
subordination in right of payment of one or more Classes of Certificates of the
same Series to the right of holders of such Class or Classes of Certificates to
receive payments. See "Description of Credit Enhancements".
 
    Unless otherwise specified in the related Prospectus Supplement for any
Series of Certificates, all Mortgage Loans will be of one or more of the
following types of Mortgage Loans of varying terms at origination:
 
        (1) fully amortizing Mortgage Loans, each providing for interest (the
    "Mortgage Interest Rate") at a fixed rate and level monthly payments of
    principal and interest over the term of such Mortgage Loan;
 
        (2) Mortgage Loans, each with an adjustable Mortgage Interest Rate,
    which may include graduated payment Mortgage Loans and other Mortgage Loans
    providing for negative amortization;
 
        (3) Mortgage Loans with either fixed or adjustable Mortgage Interest
    Rates, that do not provide for level monthly payments of principal and
    interest and/or do not provide for amortization in full by their maturity
    dates;
 
        (4) fixed-rate Mortgage Loans that do not provide for amortization in
    full by their maturity dates and which may at the end of their terms be
    converted by the Mortgagors to fully amortizing adjustable-rate Mortgage
    Loans, provided that certain conditions are met; and
 
                                       11
<PAGE>
        (5) any other type of Mortgage Loan described in the applicable
    Prospectus Supplement.
 
    If so specified in the related Prospectus Supplement for any Series of
Certificates, a Mortgage Pool may contain Buydown Loans which include provisions
whereby the Seller or a third party partially subsidizes the monthly payments of
the Mortgagor during the initial portion of the term of the Buydown Loan, the
difference to be made up from a fund (the "Buydown Fund") contributed by the
Seller or a third party at the time of origination of the Mortgage Loan. A
Buydown Fund will be in an amount equal either to the discounted value or full
aggregate amount of future payment subsidies. The applicable Prospectus
Supplement or Current Report on Form 8-K will contain information with respect
to any Buydown Loans, including information on the interest rate initially
payable by the Mortgagor, annual increases in the interest rate, the length of
the buydown period and the Buydown Fund. The underlying assumption of buydown
plans is that the income of the Mortgagor will increase during the buydown
period as a result of normal increases in compensation and of inflation, so that
the Mortgagor will be able to meet the full mortgage payments at the end of the
buydown period. To the extent that this assumption as to increased income is not
correct, the possibility of defaults on Buydown Loans is increased.
 
    The aggregate principal balances of the Mortgage Loans in each Mortgage Pool
on the date specified in the related Prospectus Supplement as the Cut-Off Date
will be at least $5,000,000. Unless otherwise specified in the Prospectus
Supplement of a particular Series, each Mortgage Loan at origination will have
an outstanding principal balance of not less than $30,000 nor more than
$1,000,000. With respect to each Mortgage Pool, unless otherwise specified in
the related Prospectus Supplement, all principal and interest payments on the
Mortgage Loans due prior to the Cut-Off Date will have been made.
 
    For each Mortgage Pool, the related Prospectus Supplement will generally
contain specific information as of the Cut-Off Date regarding (i) the aggregate
principal balance of the Mortgage Loans; (ii) the range of Mortgage Interest
Rates or initial Mortgage Interest Rates borne by the Mortgage Loans; (iii) the
month and year in which the first monthly payments occur, and the latest
maturity of the Mortgage Loans; (iv) the largest and smallest principal balances
of the Mortgage Loans at origination; (v) the aggregate principal balance of all
Mortgage Loans having loan-to-value ratios at origination exceeding 80%; (vi)
the types of dwellings constituting the Mortgaged Properties securing the
Mortgage Loans; (vii) the percentage of the Mortgage Loans (by principal
balance) of nonowner occupied and of second and vacation properties; (viii) the
geographic distribution of the Mortgage Loans, prepared on a state-by-state
basis for states containing 5% or more of the Mortgage Pool; and (ix) the number
and aggregate principal balance of Buydown Loans.
 
    Specific information with respect to the Mortgage Loans in a particular
Mortgage Pool and the applicable credit enhancements which is not included in
the related Prospectus Supplement will generally be included in a Current Report
on Form 8-K which will be available to purchasers of the Certificates at or
before the time of initial issuance of the related Series of Certificates, and
which will be filed with the Securities and Exchange Commission (the
"Commission") within 15 days thereafter.
 
    Generally, the Company will act as master servicer (the "Master Servicer")
and will be responsible for administering and servicing the Mortgage Loans in
each Mortgage Pool. The Master Servicer has entered or will enter into a
contract with each Seller/Servicer to perform, as an independent contractor,
certain servicing functions for the Master Servicer subject to its supervision
and may enter into a contract with an independent entity to perform
administration functions for the Mortgage Pools, subject to the Master
Servicer's supervision. Unless otherwise specified in the applicable Prospectus
Supplement, the Master Servicer will reserve the right to remove the Seller/
Servicer of any Mortgage Loan at any time if the Master Servicer considers such
removal to be in the best interests of Certificateholders. In such event, the
Master Servicer would continue to be responsible for servicing such Mortgage
Loan and intends to designate a replacement Seller/Servicer (which may include
the Company or an affiliate of the Company). The Master Servicer may perform its
administrative and servicing responsibilities through agents or independent
contractors, but shall not thereby be released from any of its responsibilities
under the Pooling Agreement. The Master Servicer will receive a fee (the "Master
Servicing Fee") for its services. The Seller/Servicers will perform certain
servicing functions for the Company pursuant to servicing contracts (the
"Servicing Contracts") with the Master Servicer and will receive a fee for
acting as the primary servicer of the
 
                                       12
<PAGE>
related Mortgage Loans (the "Servicing Fee"). The fees to the Master Servicer
and the Seller/ Servicers will be paid from the difference between the Mortgage
Interest Rates on each Mortgage Loan and the Remittance Rate with respect to
such Mortgage Loan.
 
    If so specified in the applicable Prospectus Supplement, the Company will
not act as Master Servicer for a particular Series of Certificates. In such
event, (i) the servicing of the Mortgage Loans will be performed by the Servicer
specified in the applicable Prospectus Supplement, (ii) there will not be a
Master Servicer, and (iii) the Certificate Administrator will calculate amounts
distributable to the Certificateholders, prepare tax returns on behalf of the
Trust Fund and provide certain other administrative services specified in the
Pooling Agreement. The Servicer and the Certificate Administrator may perform
their respective servicing and administrative responsibilities through agents or
independent contractors, but shall not thereby be released from any of their
respective responsibilities under the Pooling Agreement. With respect to such
Series of Certificates, the Servicer will receive the Servicing Fee and the
Certificate Administrator will receive a fee for its services (the "Certificate
Administrator Fee"), each of which will be paid from the difference between the
Mortgage Interest Rate on each Mortgage Loan and the Remittance Rate with
respect to such Mortgage Loan.
 
    Unless otherwise specified in the applicable Prospectus Supplement, the
Certificates of each Series will represent undivided interests in a Trust Fund
consisting of the Mortgage Loans included in the Mortgage Pool for that Series
and related property. Certain Series will be enhanced by mortgage loan insurance
or other forms of credit enhancement, in each case as more fully described
herein under the captions "Description of Certificates" and "Description of
Credit Enhancements" and/or in the related Prospectus Supplement. When each
Series of Certificates is issued, the Company will cause the Mortgage Loans in
the Mortgage Pool for that Series to be assigned to an independent bank or trust
company as trustee (the "Trustee") for the benefit of the holders of
Certificates of that Series, and the Master Servicer or the Servicer will be
responsible for servicing the Mortgage Loans pursuant to a separate pooling and
servicing agreement ("Pooling Agreement") for the Series.
 
    The Company's assignment of the Mortgage Loans to the Trustee will be
without recourse, and the Company's obligations with respect to the Mortgage
Loans will, unless otherwise indicated in the Prospectus Supplement for a Series
of Certificates, be limited to any representations and warranties made by it in,
as well as its contractual obligations under, the Pooling Agreement for each
Series. These obligations consist primarily of the obligation to administer and,
if applicable, service the Mortgage Loans and, with respect to Series of
Certificates as to which the Company will act as Master Servicer and unless
otherwise stated in the Prospectus Supplement for such Series, in the event of
delinquencies in payments on the Mortgage Loans in any Mortgage Pool, to advance
cash ("Advances") in the amounts described herein under "Description of
Certificates--Advances", to the extent such Advances are not made by the
Seller/Servicers. Any such Advances by the Master Servicer will be limited to
amounts which, in the judgment of the Master Servicer, ultimately will be
reimbursable with respect to such Mortgage Pool from Mortgagor payments or under
any applicable Mortgage Pool Insurance Policy, any applicable Special Hazard
Insurance Policy, any Primary Insurance Policy, FHA Insurance Policy or VA
Guaranty issued with respect to a Mortgage Loan, any applicable Letter of
Credit, Reserve Fund or any other applicable policy of insurance, any
subordination feature described herein or the proceeds of liquidation of a
Mortgage Loan. See "Description of Credit Enhancements". Unless otherwise
specified in the applicable Prospectus Supplement, each Seller/Servicer will be
obligated, in the event of delinquencies on the Mortgage Loans serviced by it in
any Mortgage Pool, to make Advances limited to amounts which, in its judgment,
after consultation with the Master Servicer, ultimately will be reimbursable
from the sources stated above. If so specified in the applicable Prospectus
Supplement, neither the Master Servicer nor the Seller/Servicers will be
obligated to make Advances with respect to Mortgage Loans delinquent longer than
the time period specified in such Prospectus Supplement. See "Description of
Certificates--Advances" and "Description of Credit Enhancements". The Master
Servicer is obligated to remit to Certificateholders of a Series all amounts
relating to the Mortgage Loans to the extent such amounts have been collected or
advanced by the Seller/Servicers or advanced by the Master Servicer and are due
Certificateholders pursuant to the terms of the Pooling Agreement for such
Series. With respect to Series of Certificates as to which the Company will not
act as Master Servicer and the servicing of the Mortgage Loans will be performed
by the Servicer, unless otherwise stated in the applicable Prospectus
Supplement, the Servicer will be obligated to make Advances in
 
                                       13
<PAGE>
the amounts described herein under "Description of Certificates--Advances",
limited to amounts which, in the judgment of the Servicer, ultimately will be
reimbursable with respect to such Mortgage Pool from any of the sources stated
above.
 
CONVERSION OF MORTGAGE LOANS
 
    The Prospectus Supplement for certain Series of Certificates representing
undivided interests in a Trust Fund consisting of adjustable-rate Mortgage Loans
may provide that some or all of the Mortgage Loans in the related Mortgage Pool
may have a conversion feature. Unless otherwise specified in the related
Prospectus Supplement, each such Mortgage Loan may be converted at the
Mortgagor's option at any time during a specified initial period to a fixed-rate
Mortgage Loan, subject to the Seller/Servicer's or the Servicer's determination
that the Mortgagor has met certain payment history requirements and the payment
of a conversion fee ("Conversion Fee") to the Seller/Servicer or the Servicer,
as applicable. Unless otherwise specified in the applicable Prospectus
Supplement, upon any such conversion, the Master Servicer, or the Seller with
respect to Series of Certificates as to which the Company will not act as Master
Servicer, will repurchase the Mortgage Loan from the Mortgage Pool at its then
outstanding principal balance, plus interest at the Mortgage Interest Rate on
such Mortgage Loan to the date of repurchase. The amounts distributable to
Certificateholders of different Classes, if applicable, upon such repurchase,
and the portion of the Conversion Fee to be passed through to
Certificateholders, if any, will be set forth in the Prospectus Supplement for
each such Series of Certificates.
 
                                USE OF PROCEEDS
 
    All of the net proceeds to be received from the sale of each Series of the
Certificates will be used by the Company to purchase the Mortgage Loans related
to that Series or to return to the Company the amounts previously used to effect
such purchases, the costs of carrying the Mortgage Loans until sale of the
Certificates and other expenses connected with pooling the Mortgage Loans and
issuing the Certificates, or for general corporate purposes. The Company expects
to issue Certificates in Series from time to time as part of its continuing
program of acquiring Mortgage Loans and selling Certificates. See "The
Company--Mortgage Purchase Program".
 
                              YIELD CONSIDERATIONS
 
GENERAL
 
    The yield to maturity on any Certificate will depend on the purchase price
paid by the Certificateholder, the effective interest rate of the Certificate
and the weighted average life of the Mortgage Loans underlying the Certificate.
See "Maturity, Average Life and Prepayment Assumptions" for a discussion of
weighted average life. Any prepayment of a Mortgage Loan or liquidation of a
Mortgage Loan (by foreclosure proceedings or by virtue of the purchase of a
Mortgage Loan in advance of its stated maturity or otherwise) will have the
effect of passing through to Certificateholders amounts of principal which would
otherwise be passed through in amortized increments over the remaining term of
such Mortgage Loan. The effect of such prepayments on the yield to maturity to
Certificateholders depends on several factors. For example, if the Certificates
are purchased above par (I.E., for more than 100% of the outstanding principal
balance of the Mortgage Loans they represent), such prepayments will tend to
decrease the yield to maturity. If the Certificates were purchased at a discount
(I.E., for less than 100% of such outstanding principal balance), such
prepayments will tend to increase the yield to maturity. See "Certain Legal
Aspects of the Mortgage Loans--Enforceability of Certain Provisions" for a
description of certain provisions of each Mortgage Loan and statutory,
regulatory and judicial developments that may affect the prepayment experience
and maturity assumptions on the Mortgage Loans. See also "Description of
Certificates-- Termination" for a description of the repurchase of the Mortgage
Loans in any Mortgage Pool when the aggregate outstanding principal balance
thereof is less than a specified percentage of the aggregate outstanding
principal balance of the Mortgage Loans in such Mortgage Pool on the related
Cut-Off Date.
 
    The timing of changes in the rate of principal payments on or repurchases of
the Mortgage Loans may significantly affect an investor's actual yield to
maturity, even if the average rate of principal payments experienced over time
is consistent with an investor's expectation. In general, the earlier a
 
                                       14
<PAGE>
prepayment of principal on the underlying Mortgage Loans or a repurchase
thereof, the greater will be the effect on an investor's yield to maturity. As a
result, the effect on an investor's yield to maturity of principal payments and
repurchases occurring at a rate higher (or lower) than the rate anticipated by
the investor during the period immediately following the issuance of a Series of
Certificates would not be fully offset by a subsequent like reduction (or
increase) in the rate of principal payments.
 
EFFECTIVE INTEREST RATE
 
    Unless otherwise specified in the applicable Prospectus Supplement, each
monthly interest payment on a Mortgage Loan is calculated as 1/12 of the
applicable Mortgage Interest Rate multiplied by the unpaid principal balance
outstanding on the first day of the month after application of principal
payments made on such date. Unless otherwise specified in the applicable
Prospectus Supplement, the Remittance Rate for each Class of Certificates will
be calculated on the basis of the "Pass-Through Rate" for the related Mortgage
Loans. With respect to a Series of Certificates as to which the Company will act
as Master Servicer, the "Pass-Through Rate" for any Mortgage Loan will equal the
related Mortgage Interest Rate less the sum of the Servicing Fee and the Master
Servicing Fee for such Mortgage Loan. With respect to a Series of Certificates
as to which the Company will not act as Master Servicer, the "Pass-Through Rate"
for any Mortgage Loan will equal the related Mortgage Interest Rate less the sum
of the Servicing Fee and the Certificate Administrator Fee for such Mortgage
Loan.
 
    As described in the applicable Prospectus Supplement, in certain events, if
the amounts available for distribution in respect of interest are not sufficient
to cover the total of all accrued and unpaid interest at the Pass-Through Rate,
the available amount will be distributed to the Certificateholders pro rata in
accordance with their respective interests or in an order of priority described
in the applicable Prospectus Supplement.
 
    For the sale of Certificates under this Prospectus, the Company may
establish one or more Mortgage Pools having a variable, as opposed to a fixed,
Pass-Through Rate. A Mortgage Pool with a variable Pass-Through Rate may be
composed of Mortgage Loans that have adjustable Mortgage Interest Rates, or of
Mortgage Loans with fixed Mortgage Interest Rates if the amount to be passed
through is determined on a Mortgage Loan-by-Mortgage Loan basis as the Mortgage
Interest Rate minus specified fees for servicing and administrative
compensation, which may include any of the Servicing Fee, the Master Servicing
Fee and the Certificate Administrator Fee, for each such Mortgage Loan, as set
forth in the Prospectus Supplement, or as otherwise determined as described in
the applicable Prospectus Supplement. Because the Mortgage Interest Rates may
vary in such a Mortgage Pool, and the servicing and administrative compensation
generally will be fixed, the Pass-Through Rate will be affected by
disproportionate principal prepayments among Mortgage Loans bearing different
Mortgage Interest Rates and, consequently, the yield to maturity
Certificateholders will be affected. The characteristics of any such
variable-rate Mortgage Pools will be described in the applicable Prospectus
Supplement. Although Mortgage Interest Rates in a fixed Pass-Through Rate
Mortgage Pool may vary from Mortgage Loan to Mortgage Loan, disproportionate
principal prepayments among the Mortgage Loans bearing different Mortgage
Interest Rates will not affect the return to Certificateholders.
 
    For any Series of Certificates, the effective yield to maturity to
Certificateholders generally will be slightly lower than the yield to maturity
otherwise produced by the applicable Pass-Through Rate because, while interest
will accrue on each Mortgage Loan from the first day of each month, the
distribution of such interest to Certificateholders at the applicable
Pass-Through Rate generally will be made on a later day, which, unless otherwise
specified in the applicable Prospectus Supplement, will be the 25th day (or, if
such day is not a business day, the next succeeding business day) of the month
following the month of accrual.
 
    When a prepayment in full (a "Payoff") is made by a Mortgagor on a Mortgage
Loan during a month, the Mortgagor is charged interest on the days in the month
actually elapsed up to the date of the Payoff at the daily interest rate
(determined by dividing the Mortgage Interest Rate by 365, or 360 in the case of
Payoffs received on a date on which the monthly payment for such Mortgage Loan
is due (a "Due Date")) which is applied to the principal amount of the Mortgage
Loan so prepaid. Similarly, when a Mortgage Loan is liquidated under a Mortgage
Pool Insurance Policy during a month, the pool insurer will pay interest on the
Mortgage Loan only to the date the claim is paid. Also, when a partial
 
                                       15
<PAGE>
principal prepayment (a "Curtailment") is made on a Mortgage Loan together with
the scheduled Monthly Payment for a month on or after the related Due Date, the
Mortgagor does not pay interest on the prepaid amount, and therefore
Certificateholders will not receive any interest on such prepaid amount.
 
    Unless otherwise specified in the applicable Prospectus Supplement, to the
extent that Compensating Interest (as defined below) is not paid, the effect of
a Payoff or such a liquidation will be to reduce slightly the amount of interest
passed through on the next Distribution Date, because interest on the principal
amount of the Mortgage Loan so prepaid was paid only to the date of such Payoff
or liquidation and not to the end of the month of prepayment. Unless otherwise
specified in the applicable Prospectus Supplement, the following will apply:
Payoffs received during the period from the first day of a calendar month
through the 14th day of such month will be passed through, without Compensating
Interest and without interest accrued from the first day of such month to the
date of the Payoff, on the Distribution Date in such month, and Payoffs received
during the period from the 15th day of a calendar month through the last day of
such month will be passed through, with Compensating Interest and with interest
at the applicable Pass-Through Rate attributable to interest paid through the
date of the Payoff by the Mortgagors on the Distribution Date in the following
month. Proceeds of Mortgage Loans liquidated under a Mortgage Pool Insurance
Policy during a month will be passed through, with Compensating Interest and
interest at the applicable Pass-Through Rate attributable to interest paid by
the pool insurer under an applicable Mortgage Pool Insurance Policy, on the
Distribution Date in the following month.
 
    Unless otherwise specified in the applicable Prospectus Supplement, the
following will apply: "Compensating Interest" will consist of a full month's
payment of interest at the applicable Pass-Through Rate on a Mortgage Loan for
which a Payoff is made or which is liquidated, less the interest at the
applicable Pass-Through Rate attributable to interest paid by the Mortgagor or
by the pool insurer under an applicable Mortgage Pool Insurance Policy through
the date of Payoff. Compensating Interest on liquidated Mortgage Loans will be
passed through to Certificateholders, together with any interest at the
applicable Pass-Through Rate attributable to interest paid by the pool insurer
under any applicable Mortgage Pool Insurance Policy to the date of liquidation
on the Distribution Date of the month following liquidation. Compensating
Interest on Payoffs will be paid on a Distribution Date only with respect to
Payoffs received during the period from the 15th day of the preceding calendar
month through the last day of such preceding month. The applicable Pooling and
Servicing Agreement will specify any limitations on the extent of or source of
funds available for payments of Compensating Interest.
 
               MATURITY, AVERAGE LIFE AND PREPAYMENT ASSUMPTIONS
 
    The Mortgage Loans at origination will have varying maturities as more fully
described in the applicable Prospectus Supplement. The Company expects that most
such Mortgage Loans will have maturities at origination of either 10 to 15 years
or 20 to 30 years and that such Mortgage Loans may be prepaid in full or in part
at any time, generally without penalty. The prepayment experience will affect
the lives of the Certificates. The Company anticipates that a substantial number
of Mortgage Loans will be paid in full prior to their scheduled maturity.
 
    A number of factors, including homeowner mobility, economic conditions,
enforceability of "due-on-sale" clauses, assumability of the Mortgage Loans,
mortgage market interest rates and the general availability of mortgage funds
affect prepayment experience. Generally, each Mortgage executed in connection
with a fixed-rate Mortgage Loan, except for FHA-insured or VA-guaranteed
Mortgage Loans, will contain "due-on-sale" provisions permitting the holder of
the Mortgage Note to accelerate the maturity of the Mortgage Loan upon
conveyance by the Mortgagor of the underlying Mortgaged Property. With respect
to Series of Certificates as to which the Company will act as Master Servicer,
the Master Servicer will agree that it or the applicable Seller/Servicer will
enforce any "due-on-sale" clause contained in any such Mortgage to the extent it
has knowledge of the conveyance or proposed conveyance of the underlying
Mortgaged Property and reasonably believes that it is entitled to do so under
applicable law; provided, however, that neither the Master Servicer nor the
Seller/Servicer will take any action in relation to the enforcement of any
"due-on-sale" provision which would impair or threaten to impair any recovery
under any related Primary Insurance Policy or Mortgage Pool Insurance Policy.
With respect to Series of Certificates as to which the Company will not act as
Master
 
                                       16
<PAGE>
Servicer, the Servicer will agree to enforce any "due-on-sale" clause in the
instances and to the extent described in the preceding sentence. However, a
Mortgage Pool may contain fixed-rate Mortgage Loans which will allow a
subsequent owner of a Mortgaged Property, if credit underwriting standards are
met, to assume such fixed-rate Mortgage Loan without enforcement of any
"due-on-sale" clause. With respect to Mortgage Loans bearing adjustable Mortgage
Interest Rates, unless otherwise specified in the related Prospectus Supplement,
the related Mortgages will generally provide that such Mortgage Loans are
assumable by creditworthy subsequent owners without enforcement of any "due-
on-sale" clause. An assumption of a Mortgage Loan may have the effect of
increasing the life of such Mortgage Loan.
 
    "Weighted average life" refers to the average amount of time that will
elapse from the date of issuance of a Certificate until each dollar of principal
will be repaid to the Certificateholders. The weighted average life of the
Certificates will be influenced by the rate at which principal on the Mortgage
Loans in the Mortgage Pool is paid, which may be in the form of (i) scheduled
amortization or (ii) Curtailments and Payoffs (collectively "Principal
Prepayments"). Based upon published information, the rate of prepayments on
fixed- and adjustable-rate conventional one-to four-family mortgage loans has
fluctuated significantly in recent years. The Company believes such fluctuation
is due to a number of factors, including those discussed above, and that such
factors will also affect the prepayment experience on the Mortgage Loans in any
Mortgage Pool. Accordingly, the Company cannot predict what future prepayment
experience will be or what the resulting weighted average life might be.
However, principal prepayments on mortgage loans are commonly measured relative
to a prepayment standard or model. The model used in this Prospectus and in each
Prospectus Supplement, unless otherwise indicated therein (the "Basic Prepayment
Assumption" or "BPA"), represents an assumed rate of prepayment each month
relative to the then outstanding principal balance of a pool of new Mortgage
Loans. The BPA assumes prepayment rates of 0.2% per annum of the then
outstanding principal balance of such Mortgage Loans in the first month of the
life of the Mortgage Loans and an additional 0.2% per annum in each month
thereafter until the 30th month. Beginning in the 30th month and in each month
thereafter during the life of the Mortgage Loans, such prepayment model assumes
a constant prepayment rate of 6.0% per annum. Varying prepayment assumptions are
often expressed as percentages of the BPA (E.G., at 150% of the BPA, assumed
prepayments during the first month of a pool would be 0.3% per annum, each month
thereafter the rate of prepayments would increase by 0.3% per annum, and in the
30th and succeeding months the rate would be 9% per annum). The Prospectus
Supplement or Current Report on Form 8-K for each Series of Certificates may
contain a table setting forth the projected weighted average life of each Class
of Certificates of such Series and the percentage of the original principal
amounts or notional principal amounts of each such Class that would be
outstanding on specified Distribution Dates for such Series, based on the
assumptions set forth with respect to the BPA deemed appropriate by the Company
and specified therein.
 
                                  THE COMPANY
 
    The Company, a Delaware corporation, is a wholly-owned indirect subsidiary
of PNC Bank Corp., a bank holding company. The Company was organized for the
purpose of providing mortgage lending institutions, including affiliated
institutions, with greater financing and lending flexibility by purchasing
mortgage loans from such institutions and issuing mortgage-backed securities.
The Company's principal executive offices are located at 75 North Fairway Drive,
Vernon Hills, Illinois 60061, telephone (847) 549-6500.
 
MORTGAGE PURCHASE PROGRAM
 
    Set forth below is a description of the principal aspects of the Company's
purchase program for Mortgage Loans eligible for inclusion in a Mortgage Pool.
The Company will represent and warrant to the Trustee that each Mortgage Pool
will consist of Mortgage Loans purchased from one or more institutions
("Sellers") which are (i) state-chartered or federally-chartered savings and
loan associations, banks or similar financial institutions whose deposits or
accounts are insured by the Federal Deposit Insurance Corporation ("FDIC") or,
if specified in the applicable Prospectus Supplement or Current Report on Form
8-K, substantially similar deposit insurance approved by any applicable rating
agency, (ii) approved as mortgagees by the FHA ("FHA-Approved Mortgagees"),
(iii) approved by the Federal National Mortgage Association ("FNMA") as
mortgagees ("FNMA-
 
                                       17
<PAGE>
Approved Mortgagees") or by the Federal Home Loan Mortgage Corporation ("FHLMC")
as mortgagees ("FHLMC-Approved Mortgagees"), or any successor entity to either,
(iv) assignees of FHA-Approved Mortgagees, FNMA-Approved Mortgagees or
FHLMC-Approved Mortgagees, (v) the FDIC or the Resolution Trust Corporation,
(vi) entities which have purchased Mortgage Loans from institutions described in
clauses (i)-(v) above or (vii) such other entities as may be described in the
applicable Prospectus Supplement. The institutions described in clauses (i)-(v)
of the preceding sentence will collectively be referred to herein as "Lenders".
The Company has approved (or will approve) individual institutions as eligible
Lenders by applying certain criteria, including the Lender's depth of mortgage
origination experience, servicing experience and financial stability. In
general, each Lender must have experience in originating and servicing
conventional residential mortgages and must have a net worth acceptable to the
Company. Each Lender is required to use the services of qualified underwriters,
appraisers and attorneys. Other factors evaluated by the Company in approving
Lenders include delinquency and foreclosure ratio performances.
 
LOAN STANDARDS
 
    The Mortgage Loans to be included in each Mortgage Pool will be loans with
fixed or adjustable rates of interest secured by first mortgages, deeds of trust
or security deeds on residential properties with original principal balances
which did not exceed 95% of the value of the Mortgaged Properties, unless such
loans are FHA-insured or VA-guaranteed. Generally, each Mortgage Loan having a
loan-to-value ratio at origination and as of the Cut-Off Date in excess of 80%
or which is secured by a second or vacation home will be covered by a Primary
Insurance Policy, FHA Insurance Policy or VA Guaranty insuring against default
all or a specified portion of the principal amount thereof. See "Primary
Insurance, FHA Mortgage Insurance, VA Mortgage Guaranty, Hazard Insurance;
Claims Thereunder". Each mortgage insurer must be a Qualified Insurer (defined
herein to mean a mortgage guaranty insurance company which is duly qualified as
such under the laws of each state in which the Mortgaged Properties are located,
duly authorized and licensed in such states to transact a mortgage guaranty
insurance business and to write the insurance provided by the Primary Insurance
Policy or the Mortgage Pool Insurance Policy, as the case may be, and which is
approved as an insurer by FHLMC, FNMA or any successor entity to either, and by
the Company).
 
    The Mortgage Loans to be included in each Mortgage Pool will be "one- to
four-family" mortgage loans, which means permanent loans (as opposed to
construction or land development loans) secured by Mortgages on non-farm
properties, including attached or detached single-family or second/vacation
homes, two-to four-family primary residences and condominiums or other attached
dwelling units, including individual condominiums, row houses, townhouses and
other separate dwelling units even when located in buildings containing five or
more such units. Each Mortgage Loan must be secured by an owner occupied primary
residence or second/vacation home, or by a nonowner occupied residence. The
Mortgaged Property may not be a mobile home.
 
CREDIT, APPRAISAL AND UNDERWRITING STANDARDS
 
    The Mortgage Loans to be included in each Mortgage Pool will be subject to
the various credit, appraisal and underwriting standards described herein. The
Company's credit, appraisal and underwriting standards with respect to certain
Mortgage Loans will generally conform to those published in the Company's
Selling Guide (together with the Company's Servicing Guide, the "Guide", as
modified from time to time). The credit, appraisal and underwriting standards as
set forth in the Guide are continuously revised based on opportunities and
prevailing conditions in the residential mortgage market and the market for the
Company's mortgage pass-through certificates. The Mortgage Loans may be
underwritten by the Company or by designated third parties.
 
    In addition, the Company may purchase Mortgage Loans which do not conform to
the underwriting standards set forth in the Guide. Such Mortgage Loans may be
purchased in negotiated transactions from Sellers who will represent that the
Mortgage Loans have been originated in accordance with credit, appraisal and
underwriting standards agreed to by the Company. The Company will generally
review only a limited portion of the Mortgage Loans in any delivery of such
Mortgage Loans for conformity with the applicable credit, appraisal and
underwriting standards. Certain other Mortgage Loans will be purchased from
Sellers who will represent that the Mortgage Loans were originated pursuant to
credit, appraisal and underwriting standards determined by a
 
                                       18
<PAGE>
mortgage insurance company acceptable to the Company. The Company will accept a
certification from such insurance company as to a Mortgage Loan's insurability
in a mortgage pool as of the date of certification as evidence that such
Mortgage Loan conforms to applicable underwriting standards. Such certifications
will likely have been issued before the purchase of the Mortgage Loans by the
Company. The Company will perform only random quality assurance reviews on
Mortgage Loans delivered with such certifications.
 
    The credit, appraisal and underwriting standards utilized in negotiated
transactions and the credit, appraisal and underwriting standards of insurance
companies issuing certificates may vary substantially from the credit, appraisal
and underwriting standards set forth in the Guide. All of the credit, appraisal
and underwriting standards will provide an underwriter with sufficient
information to evaluate the borrower's repayment ability and the adequacy of the
Mortgaged Property as collateral. Due to the variety of underwriting standards
and review procedures that may be applicable to the Mortgage Loans included in
any Mortgage Pool, the related Prospectus Supplement will not distinguish among
the various credit, appraisal and underwriting standards applicable to the
Mortgage Loans nor describe any review for compliance with applicable credit,
appraisal and underwriting standards performed by the Company. Moreover, there
can be no assurance that every Mortgage Loan was originated in conformity with
the applicable credit, appraisal and underwriting standards in all material
respects, or that the quality or performance of Mortgage Loans underwritten
pursuant to varying standards as described above will be equivalent under all
circumstances.
 
    The Company's underwriting standards are intended to evaluate the
prospective Mortgagor's credit standing and repayment ability, and the value and
adequacy of the proposed Mortgaged Property as collateral. In the loan
application process, prospective Mortgagors will be required to provide
information regarding such factors as their assets, liabilities, income, credit
history, employment history and other related items. Each prospective Mortgagor
will also provide an authorization to apply for a credit report which summarizes
the Mortgagor's credit history. With respect to establishing the prospective
Mortgagor's ability to make timely payments, the Company will require evidence
regarding the Mortgagor's employment and income, and of the amount of deposits
made to financial institutions where the Mortgagor maintains demand or savings
accounts. In some instances, Mortgage Loans which were originated under a
Limited Documentation Origination Program may be sold to the Company. For a
mortgage loan originated under a Limited Documentation Origination Program to
qualify for purchase by the Company, the prospective mortgagor must have a good
credit history and be financially capable of making a larger cash down payment,
in a purchase, or be willing to finance less of the appraised value, in a
refinancing, than would otherwise be required by the Company. Currently, the
Company's underwriting standards provide that only mortgage loans with certain
loan-to-value ratios will qualify for purchase. If the mortgage loan qualifies,
the Company waives some of its documentation requirements and eliminates
verification of income and employment for the prospective mortgagor.
 
    The Company's underwriting standards generally follow guidelines acceptable
to FNMA and FHLMC. In determining the adequacy of the property as collateral, an
independent appraisal is made of each property considered for financing. The
appraiser is required to inspect the property and verify that it is in good
condition and that construction, if new, has been completed. The appraisal is
based on the appraiser's judgment of values, giving appropriate weight to both
the market value of comparable homes and the cost of replacing the property.
 
    Certain states where the Mortgaged Properties may be located are
"anti-deficiency" states where, in general, lenders providing credit on one- to
four-family properties must look solely to the property for repayment in the
event of foreclosure. See "Certain Legal Aspects of the Mortgage
Loans--Anti-Deficiency Legislation and Other Limitations on Lenders." The
Company's underwriting standards in all states (including anti-deficiency
states) require that the underwriting officers be satisfied that the value of
the property being financed, as indicated by the independent appraisal,
currently supports and is anticipated to support in the future the outstanding
loan balance, and provides sufficient value to mitigate the effects of adverse
shifts in real estate values.
 
                                       19
<PAGE>
SELLER WARRANTIES AND INDEMNIFICATION OF THE COMPANY
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, each Seller generally will make representations and warranties
with respect to Mortgage Loans sold by it to the Company for inclusion in the
Trust Fund which the Company deems sufficient to permit it to make its
representations and warranties in respect of such Mortgage Loans to the Trustee
and the Certificateholders under the Pooling Agreement. See "Description of
Certificates--Representations and Warranties" below. Each Seller will also make
certain other representations and warranties regarding Mortgage Loans sold by
it. Upon the breach of any representation or warranty made by a Seller that
materially and adversely affects the interests of the Certificateholder in a
Mortgage Loan (other than those breaches which have been cured), the Company may
require the Seller to repurchase the related Mortgage Loan. In addition, each
Seller will agree to indemnify the Company against any loss or liability
incurred by the Company on account of any breach of any representation or
warranty made by the Seller, any failure to disclose any matter that makes any
such representation and warranty misleading, or any inaccuracy in information
furnished by the Seller to the Company, including any information set forth in
this Prospectus or in any Prospectus Supplement. See "Description of
Certificates--Assignment of Mortgage Loans" and "--Representations and
Warranties".
 
    With respect to Series of Certificates as to which the Company will not act
as Master Servicer, the Seller which sold the Mortgage Loans to the Company for
inclusion in the Trust Fund will make representations and warranties to the
Company with respect to such Mortgage Loans, and the Company will assign such
representations and warranties to the Trustee and the Certificateholders under
the Pooling Agreement. Upon the breach of any representation or warranty made by
such Seller that materially and adversely affects the interests of the
Certificateholder in a Mortgage Loan (other than those breaches which have been
cured), the Seller will be required to repurchase the related Mortgage Loan. See
"Description of Certificates--Assignment of Mortgage Loans" and
"--Representations and Warranties".
 
RELATIONSHIPS WITH AFFILIATES
 
    PNC Mortgage Corp. of America, an affiliate of the Company, may be a Seller,
a Seller/Servicer or a Servicer. Two of the Company's directors are also
directors of PNC Mortgage Corp. of America.
 
                          DESCRIPTION OF CERTIFICATES
 
    Each Series of Certificates will be issued pursuant to a separate Pooling
Agreement. With respect to Series of Certificates as to which the Company will
act as Master Servicer, the Pooling Agreement will be between the Company, as
Depositor and Master Servicer, and the Trustee named in the Prospectus
Supplement, and the Mortgage Loans will be serviced by Seller/Servicers pursuant
to selling and servicing contracts ("Selling and Servicing Contracts") between
the Company and such Seller/Servicers, or will be serviced by servicers pursuant
to servicing arrangements approved by the Company. With respect to Series of
Certificates as to which the Company will not act as Master Servicer, the
Pooling Agreement will be among the Company, as Depositor and Certificate
Administrator, the Servicer and the Trustee named in the Prospectus Supplement.
A form of Pooling Agreement and a form of the Selling and Servicing Contract are
filed as exhibits to the Registration Statement of which this Prospectus is a
part. The following discussion summarizes certain provisions expected to be
contained in each Pooling Agreement which governs the Trust Funds consisting
principally of one- to-four family residential properties. The applicable
Prospectus Supplement will describe material features of the related Pooling
Agreement, which may differ from the features described below. The following
summary and the summary contained in a Prospectus Supplement do not purport to
be complete and are subject to, and are qualified in their entirety by reference
to, all of the provisions of the Pooling Agreement for each particular Series
and of the applicable Selling and Servicing Contracts or similar contracts.
 
GENERAL
 
    The Certificates of each Series will represent undivided interests in the
Trust Fund created pursuant to the Pooling Agreement for such Series. The Trust
Fund for each Series will consist, to the extent provided in the Pooling
Agreement, of (i) such Mortgage Loans as from time to time are subject
 
                                       20
<PAGE>
to the Pooling Agreement (exclusive of any related Retained Yield (described
below), except as otherwise specified in the related Prospectus Supplement),
(ii) such assets as from time to time are held in the Certificate Account
(described below) and the Custodial Accounts for P&I (described below) related
to such Mortgage Loans (exclusive of any Retained Yield, except as otherwise
specified in the related Prospectus Supplement), (iii) property acquired by
foreclosure of Mortgage Loans or deed in lieu of foreclosure, (iv) any
combination, as specified in the related Prospectus Supplement, of a Letter of
Credit, Mortgage Pool Insurance Policy, Special Hazard Insurance Policy,
Bankruptcy Bond, Fraud Bond, Reserve Fund or other type of credit enhancement as
described under "Description of Credit Enhancements", (v) the Private
Certificates and Agency Certificates, if any, described in the applicable
Prospectus Supplement, and (vi) such other assets or rights as are described in
the applicable Prospectus Supplement. If so specified in the applicable
Prospectus Supplement, Certificates of a given Series may be issued in several
Classes, which may pay interest at different rates, may represent different
allocations of the right to receive principal and interest, and certain of which
may be subordinated to others. Any such Class of Certificates may also provide
for payments of principal only or interest only or for disproportionate payments
of principal and interest. Subordinated Classes of a given Series of
Certificates may or may not be offered by the same Prospectus Supplement as the
senior Classes of such Series.
 
    The Certificates will be freely transferable and exchangeable for
Certificates of the same Series and Class at the office set forth in such
Certificates, provided, however, that certain Classes of Certificates may be
subject to transfer restrictions set forth in such Certificates and described in
the applicable Prospectus Supplement. A reasonable service charge may be imposed
for any registration of exchange or transfer of Certificates, and the Company
may require payment of a sum sufficient to cover any tax or other governmental
charge. If specified in the applicable Prospectus Supplement, one or more
Classes of Certificates for any Series may be transferable only on the books of
The Depository Trust Company or another depository identified in such Prospectus
Supplement.
 
    Unless otherwise indicated in the applicable Prospectus Supplement,
beginning with the month following the month in which the Cut-Off Date occurs
for a Series of Certificates, distributions of principal and interest (or, where
applicable, principal only or interest only) on each Class of Certificates will
be made either by the Trustee, the Master Servicer or the Certificate
Administrator, as applicable, acting on behalf of the Trustee or a paying agent
appointed by the Trustee (the "Paying Agent") on the 25th day (or if such 25th
day is not a business day, the business day immediately following such 25th day)
of each calendar month (the "Distribution Date") to the persons in whose names
the Certificates are registered at the close of business on the last business
day of the month preceding the month in which the Distribution Date occurs (the
"Record Date"). Distributions for each Series will be made by wire transfer in
immediately available funds for the account of, or by check mailed to, each
Certificateholder of record; provided, however, that, unless otherwise specified
in the related Prospectus Supplement, the final distribution in retirement of
the Certificates for each Class of a Series will be made only upon presentation
and surrender of the Certificates at the office or agency of the Company or the
Trustee specified in the notice to Certificateholders of such final
distribution.
 
ASSIGNMENT OF MORTGAGE LOANS
 
    The Company will cause the Mortgage Loans to be assigned to the Trustee,
together with all principal and interest on the Mortgage Loans other than
principal and interest due on or before the Cut-Off Date. The Company will
expressly reserve its or a Seller's rights in and to any Retained Yield, which
accordingly will not constitute part of the Trust Fund. In addition, the
applicable Prospectus Supplement may specify that the Seller will retain the
right to a specified portion of either principal or interest, or both. The
Trustee will, concurrently with such assignment, authenticate and deliver the
Certificates or cause the Certificates to be authenticated and delivered to the
Company or its designated agent in exchange for the Trust Fund. Each Mortgage
Loan will be identified in a schedule appearing as an exhibit to the Pooling
Agreement for the related Series. Unless otherwise specified in the related
Prospectus Supplement, such schedule will include information as of the close of
business on the Cut-Off Date as to the principal balance of each Mortgage Loan,
the Mortgage Interest Rate
 
                                       21
<PAGE>
and the maturity of each Mortgage Note, the Seller/Servicer's or the Servicer's
Servicing Fee, whether a Primary Insurance Policy has been obtained for each
Mortgage Loan and the then-current scheduled monthly payment of principal and
interest for each Mortgage Loan.
 
    In addition, the Company will, as to each Mortgage Loan, deliver or cause to
be delivered to the Trustee the Mortgage Note, an assignment to the Trustee of
the Mortgage in a form for recording or filing as may be appropriate in the
state where the Mortgaged Property is located, the original recorded Mortgage
with evidence of recording or filing indicated thereon, a copy of the title
insurance policy or other evidence of title and evidence of any Primary
Insurance Policy, FHA Insurance Policy or VA Guaranty for such Mortgage Loan, if
applicable; or, in the case of each Cooperative Loan, the related Cooperative
Note, the original security agreement, the proprietary lease or occupancy
agreement, the related stock certificate and related blank stock powers, and a
copy of the original filed financing statement together with assignments thereof
from the applicable Seller to the Trustee in a form sufficient for filing. In
certain instances where original documents respecting a Mortgage Loan may not be
available prior to execution of the Pooling Agreement, the Company will deliver
such documents to the Trustee within 270 days thereafter. Notwithstanding the
foregoing, a Trust Fund may include Mortgage Loans where the original Mortgage
Note is not delivered to the Trustee if the Company delivers to the Trustee or
the custodian a copy or a duplicate original of the Mortgage Note, together with
an affidavit certifying that the original thereof has been lost or destroyed.
With respect to such Mortgage Loans, the Trustee (or its nominee) may not be
able to enforce the Mortgage Note against the related borrower. The Company will
agree to repurchase or substitute for such a Mortgage Loan in certain
circumstances (see "Description of Certificates--Representations and
Warranties").
 
    The Trustee will review the mortgage documents within 45 days of receipt
thereof to ascertain that all required documents have been properly executed and
received. The Trustee will hold such documents for each Series in trust for the
benefit of Certificateholders of such Series. With respect to Series of
Certificates as to which the Company will act as Master Servicer, if any
document is found by the Trustee not to have been properly executed or received
or to be unrelated to the Mortgage Loans identified in the Pooling Agreement,
and the Company cannot cure such defect, the Company will substitute a new
mortgage loan meeting the conditions set forth in the Pooling Agreement (see
"--Substitution of Mortgage Loans" below) or repurchase the related Mortgage
Loan from the Trustee at a price equal to 100% of the outstanding principal
balance of such Mortgage Loan, plus accrued interest thereon at the applicable
Pass-Through Rate through the last day of the month of such repurchase. With
respect to Series of Certificates as to which the Company will not act as Master
Servicer, if a defect of the type described in the preceding sentence is
discovered by the Trustee and cannot be cured by the Seller, the Seller will
substitute a new mortgage loan or repurchase the related Mortgage Loan from the
Trustee upon the terms described in the preceding sentence. The purchase price
of any Mortgage Loan so repurchased will be passed through to Certificateholders
as liquidation proceeds in accordance with the procedures specified under
"--Distributions on Certificates". This substitution or repurchase obligation
constitutes the sole remedy available to the Certificateholders or the Trustee
for such a defect in a constituent document.
 
    An assignment of each Mortgage Loan to the Trustee will be recorded or filed
except in states where, in the written opinion of counsel admitted to practice
in such state acceptable to the Company and the Trustee, such filing or
recording is not required to protect the Trustee's interest in the Mortgage Loan
against sale, further assignment, satisfaction or discharge by the Seller, the
Seller/ Servicers, the Servicer, the Company or the Master Servicer.
 
    Buydown Funds provided by the Sellers or other parties for any Buydown Loans
included in a Mortgage Pool will be (a) deposited on the date of settlement of
the sale of the Certificates to the original purchasers thereof (the "Closing
Date") into a separate account (the "Buydown Fund Account") maintained with a
bank or trust company specified in the related Prospectus Supplement, (b) held
and monitored by the Seller/Servicers or the Servicer, as applicable, in insured
Buydown Fund Accounts or (c) held in Custodial Accounts for P&I. Since Buydown
Funds may be funded at either the par values of future payment subsidies or
funded in an amount less than the par values of future payment subsidies and
determined by discounting such par values in accordance with interest
 
                                       22
<PAGE>
accruing on such values, Buydown Fund Accounts may be non-interest-bearing or
may bear interest. In no event will the amount held in any Buydown Fund Account
exceed the level of deposit insurance covering such account. Accordingly, more
than one such account may be established.
 
SUBSTITUTION OF MORTGAGE LOANS
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, the Company may substitute an eligible mortgage loan for a
defective Mortgage Loan in lieu of repurchasing such defective Mortgage Loan or
the related Mortgaged Property (a) within three months after the Closing Date
for the related Series of Certificates, and (b) within two years after such
Closing Date, if the related Mortgage Loan is a "defective obligation" within
the meaning of Section 860G(a)(4)(A)(ii) of the Code. Any mortgage loan, to be
eligible for substitution, must fit within the general description of the
Mortgage Loans set forth herein and in the related Prospectus Supplement. With
respect to Series of Certificates as to which the Company will not act as Master
Servicer, the Seller or the Servicer, as specified in the related Prospectus
Supplement, may substitute an eligible mortgage loan for a defective Mortgage
Loan in lieu of repurchasing such defective Mortgage Loan or the related
Mortgaged Property in the circumstances and to the extent described in the two
preceding sentences. See "The Mortgage Pools".
 
REPRESENTATIONS AND WARRANTIES
 
    In the Pooling Agreement for each Series of Certificates as to which the
Company will act as Master Servicer, unless otherwise stated in the applicable
Prospectus Supplement, the Company will represent and warrant to the Trustee,
among other things, that (i) the information set forth in the schedule of
Mortgage Loans is true and correct in all material respects; (ii) except in the
case of Cooperative Loans, a lender's title policy (or other satisfactory
evidence of title) was issued on the date of the origination of each Mortgage
Loan and each such policy or other evidence of title is valid and remains in
full force and effect; (iii) if a Primary Insurance Policy, FHA Insurance Policy
or VA Guaranty is required with respect to such Mortgage Loan, such policy or
guaranty is valid and remains in full force and effect as of the Closing Date;
(iv) as of the Closing Date, the Company had good title to the Mortgage Loans
and the Mortgage Notes are subject to no offsets, defenses or counterclaims,
except to the extent that the buydown agreement for a Buydown Loan forgives
certain indebtedness of a Mortgagor; (v) except in the case of Cooperative
Loans, as of the Closing Date, each Mortgage is a valid first lien on an
unencumbered estate in fee simple or leasehold interest in the Mortgaged
Property (subject only to (a) liens for current real property taxes and special
assessments, (b) covenants, conditions and restrictions, rights of way,
easements and other matters of public record as of the date of recording of such
Mortgage, such exceptions appearing of record being acceptable to mortgage
lending institutions generally or specifically reflected in the mortgage
originator's appraisal, (c) exceptions set forth in the title insurance policy
covering such Mortgaged Property and (d) other matters to which like properties
are commonly subject which do not materially interfere with the benefits of the
security intended to be provided by the Mortgage); (vi) as of the Closing Date,
each Mortgaged Property is free of damage and is in good repair, except for
ordinary wear and tear; (vii) as of the time each Mortgage Loan was originated,
the Mortgage Loan complies with all applicable state and federal laws, including
usury, equal credit opportunity, disclosure and recording laws; (viii) as of the
Closing Date, there are no delinquent tax or assessment liens against any
Mortgaged Property; and (ix) unless otherwise specified in the related
Prospectus Supplement, each Mortgage Loan was originated and will be serviced by
(a) an institution which is a member of the Federal Reserve System or the
deposits of which are insured by the FDIC, (b) an institution which is a member
of the Federal Home Loan Bank System, (c) an institution which is a FHA-Approved
Mortgagee, (d) an institution which is a FNMA-Approved Mortgagee, or (e) an
institution which is a FHLMC-Approved Mortgagee. The applicable Prospectus
Supplement and Pooling Agreement may set forth additional representations and
warranties of the Company. In addition, with respect to any Mortgage Loan as to
which the Company delivers to the Trustee or the custodian an affidavit
certifying that the original Mortgage Note has been lost or destroyed, if such
Mortgage Loan subsequently is in default and the enforcement thereof or of the
related Mortgage is materially adversely affected by the absence of the original
Mortgage Note, the Company will be obligated to repurchase or substitute for
such Mortgage
 
                                       23
<PAGE>
Loan in the manner described below. However, the Company will not be required to
repurchase or substitute for any Mortgage Loan as described above if the
circumstances giving rise to such requirement also constitute fraud in the
origination of the related Mortgage Loan.
 
    If the Mortgage Loans include Cooperative Loans, representations and
warranties with respect to title insurance or hazard insurance will not be
given. Generally, a Cooperative itself is responsible for the maintenance of
hazard insurance for property owned by such Cooperative, and the borrowers
(tenant-stockholders) of such Cooperative do not maintain hazard insurance on
their individual dwelling units. Title insurance is not obtained for Cooperative
Loans because such loans are not secured by real property. See "Certain Legal
Aspects of the Mortgage Loans--Cooperative Loans".
 
    With respect to Series of Certificates as to which the Company will not act
as Master Servicer, the Seller which sold the Mortgage Loans to the Company for
inclusion in the Trust Fund will make representations and warranties to the
Company with respect to such Mortgage Loans substantially similar to those
indicated in the second preceding paragraph, and the Company will assign such
representations and warranties to the Trustee and the Certificateholders under
the Pooling Agreement. The applicable Prospectus Supplement and Pooling
Agreement may set forth additional representations and warranties of the Seller
and/or the Company.
 
    In the event of the discovery by the Company or the Servicer of a breach of
any representation or warranty which materially and adversely affects the
interest of the Certificateholders in the related Mortgage Loan, or the receipt
of notice of such a breach from the Trustee, the Company or the Seller, as the
case may be, will cure the breach, substitute a new mortgage loan for such
Mortgage Loan or repurchase such Mortgage Loan, or any Mortgaged Property
acquired with respect thereto, on the terms set forth above under "--Assignment
of Mortgage Loans". The proceeds of any such repurchase will be passed through
to Certificateholders as liquidation proceeds. This substitution or repurchase
obligation constitutes the sole remedy available to the Certificateholders or
the Trustee for any such breach.
 
    Under the Pooling Agreement, the Master Servicer, or the Servicer with
respect to Series of Certificates for which the Company will not act as Master
Servicer, will have the right, but not the obligation, to purchase any Mortgage
Loan from the applicable Mortgage Pool in the event that such Mortgage Loan
becomes 90 days or more delinquent.
 
SERVICING
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, pursuant to the Pooling Agreement the Master Servicer will be
responsible for servicing and administering the Mortgage Loans, but will be
permitted to contract with the Seller/Servicer from whom each Mortgage Loan was
purchased, or another eligible servicing institution, to perform such functions
under the supervision of the Master Servicer as more fully described below.
 
    In the contract pursuant to which each Seller/Servicer will perform its
servicing duties, which contract will generally be the Selling and Servicing
Contract, each Seller/Servicer will agree, subject to the general supervision of
the Master Servicer or its agent, to perform diligently all services and duties
customary to the servicing of mortgage loans. The Master Servicer or its agent
will monitor each Seller/Servicer's performance and, unless otherwise specified
in the applicable Prospectus Supplement, the Master Servicer will have the right
to remove and substitute a replacement Seller/ Servicer at any time if it
considers such removal to be in the best interest of Certificateholders. The
duties performed by the Seller/Servicers include collection and remittance of
principal and interest payments, administration of mortgage escrow accounts,
collection of insurance claims and, if necessary, foreclosure. In the event a
Selling and Servicing Contract is terminated by the Company for any reason, the
Master Servicer may procure a substitute Seller/Servicer, which may be an
affiliate of the Master Servicer. During the period necessary to effect the
execution and implementation of a contract with such substitute Seller/Servicer,
all duties and responsibilities of the Seller/Servicer under the terminated
Selling and Servicing Contract will be performed by the Master Servicer. In such
event, the Master Servicer will be entitled to retain the same Servicing Fee as
was paid to the Seller/ Servicer under such terminated Selling and Servicing
Contract.
 
                                       24
<PAGE>
    With respect to Series of Certificates as to which the Company will not act
as Master Servicer, pursuant to the Pooling Agreement the servicing of the
Mortgage Loans will be performed by the Servicer, and the Company (as
Certificate Administrator) will calculate amounts distributable to the
Certificateholders, prepare tax returns on behalf of the Trust Fund and provide
certain other administrative services specified in the Pooling Agreement. The
Servicer will generally perform the same services and duties as a
Seller/Servicer under a Selling and Servicing Agreement, as well as certain
services of the Master Servicer described herein. The Trustee or its agent will
monitor the Servicer's performance and, unless otherwise specified in the
applicable Prospectus Supplement, the Trustee will have the right to remove and
substitute a replacement servicer, which may be the Company or an affiliate of
the Company, to assume the servicing obligations of the Servicer at any time if
it considers such removal to be in the best interests of Certificateholders.
During the period necessary to effect the execution and implementation of a
contract with such substitute servicer, certain duties and responsibilities of
the Servicer under the Pooling Agreement will be performed by the Trustee. In
such event, the Trustee will be entitled to retain the same Servicing Fee as was
to be paid the Servicer under the Pooling Agreement. The obligation of the
Trustee or a replacement servicer to perform the servicing duties of the
Servicer will not, however, require such party to cure any defect with respect
to any Mortgage Loan, or substitute a new mortgage loan for or repurchase a
Mortgage Loan as to which there has been a breach of a representation or
warranty made by the Seller or to cure any breach of a servicing covenant made
by the former Servicer.
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, each Seller/Servicer will retain as its Servicing Fee a portion
of the interest payable on each Mortgage Loan serviced by it. The Servicing Fee
will be established by the Company either as a fixed rate or as a rate
calculated as the difference between interest at the Mortgage Interest Rate and
interest at the rate required to be passed through to the Master Servicer (the
"Net Rate"). Unless otherwise set forth in the applicable Prospectus Supplement,
the Servicing Fee will be no less than 0.25% per annum for each individual
Mortgage Loan serviced. In addition, unless otherwise set forth in the
Prospectus Supplement, the Seller/Servicer will retain late charges, assumption
fees and similar charges to the extent collected from Mortgagors. The Company
expects that such fees and charges will be negligible in amount. Unless
otherwise provided in the applicable Prospectus Supplement, the Master Servicer
will retain as its Master Servicing Fee an amount which will be calculated as a
per annum percentage for each Mortgage Loan plus an amount calculated to
reimburse the Master Servicer for the expenses required to be borne by it,
which, unless otherwise set forth in the applicable Prospectus Supplement, will
include the Trustee's fees and premiums on or other expenses relating to any
Mortgage Pool Insurance Policy and/or other credit enhancements.
 
    With respect to Series of Certificates as to which the Company will not act
as Master Servicer, the Servicer will receive a Servicing Fee, as established in
the applicable Pooling Agreement, which, unless otherwise indicated in the
applicable Prospectus Supplement, will be no less than 0.25% per annum for each
individual Mortgage Loan serviced and the Certificate Administrator will retain
as its Certificate Administrator Fee an amount which will be calculated as a per
annum percentage for each Mortgage Loan plus an amount calculated to reimburse
the Certificate Administrator for payment by it of the Trustee's fees.
 
RETAINED YIELD
 
    For certain Series, the Company or a Seller may retain a portion of the
interest payable on each Mortgage Loan (the "Retained Yield"). The Retained
Yield will either be set as a fixed rate or will be calculated by subtracting
the Master Servicing Fee and the Remittance Rate from the Net Rate or, if
applicable, by subtracting the Servicing Fee, the Certificate Administrator Fee
and the Remittance Rate from interest at the Mortgage Interest Rate. Unless
otherwise specified in the applicable Prospectus Supplement, any such Retained
Yield and any earnings from reinvestments thereof will not be part of the Trust
Fund. The Company or the Seller, as the case may be, may at its option transfer
to a third party all or a portion of the Retained Yield for a Series of
Certificates.
 
                                       25
<PAGE>
PAYMENTS ON MORTGAGE LOANS; CUSTODIAL ACCOUNTS FOR P&I,
    INVESTMENT ACCOUNT, CERTIFICATE ACCOUNT AND RESERVE
  ACCOUNT
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, pursuant to the Servicing Contract each Seller/Servicer will
agree to establish and maintain for the Master Servicer a special custodial
account for principal and interest (the "Custodial Account for P&I"), into which
it will deposit on a daily basis (unless otherwise specified in the applicable
Prospectus Supplement) the following payments and collections received
subsequent to the Cut-Off Date (other than payments due on or before the Cut-Off
Date) with respect to the Mortgage Loans serviced by it:
 
        (i) All payments on account of principal and interest, including
    Principal Prepayments;
 
        (ii) All net proceeds received in connection with the liquidation of
    defaulted Mortgage Loans, by foreclosure or otherwise (hereinafter referred
    to as "Liquidation Proceeds"), or under any applicable credit enhancements
    or title, hazard or other insurance policy covering any Mortgage Loan, other
    than proceeds to be applied to the restoration or repair of the related
    Mortgaged Property (hereinafter referred to as "Insurance Proceeds");
 
       (iii) Any Advances of such Seller/Servicer's funds (such Advances to be
    deposited prior to the Withdrawal Date, as defined below); and
 
       (iv) All proceeds of any Mortgage Loans or property acquired in respect
    thereof repurchased as required for defects in documentation, breach of
    representations or warranties, or otherwise.
 
    Each Seller/Servicer has the option of either (i) depositing gross interest
collections in the Custodial Account for P&I, subject to withdrawal of its
related Servicing Fees, or (ii) deducting its Servicing Fees from gross interest
collections prior to deposit in such account.
 
    On the Withdrawal Date or, with the Master Servicer's approval, on a daily
basis, each Seller/ Servicer may withdraw the following amounts from its
Custodial Account for P&I:
 
        (i) Amounts received on particular Mortgage Loans as late payments of
    principal or interest and respecting which the Seller/Servicer has made an
    unreimbursed Advance;
 
        (ii) Amounts to reimburse the Seller/Servicer for Advances the Master
    Servicer has determined to be otherwise nonrecoverable; and
 
       (iii) Amounts in respect of Servicing Fees previously deposited.
 
    The Company will require that deposits in each Custodial Account for P&I be
(i) insured by the FDIC, (ii) held in a trust account in the trust department of
an institution holding such account in such manner that the rights of the Master
Servicer, the Trustee and the Certificateholders thereto shall be fully
protected against the claims of any creditors of the Seller/Servicer and of any
creditors or depositors of the institution in which such account is maintained
or (iii) held in such other account acceptable to the rating agency or agencies
for the Series of Certificates. If a Custodial Account for P&I is insured by the
FDIC and at any time the amount in such account exceeds the limits of insurance
on such account, the Seller/Servicer shall be required to withdraw such excess
from such account and remit it to the Master Servicer for deposit in the
Investment Account described below.
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer and unless otherwise specified in the related Prospectus
Supplement, not later than the 20th day of each month (or the preceding business
day if such 20th day is not a business day) (the "Withdrawal Date"), the Master
Servicer will withdraw or direct the withdrawal from any funds in the Custodial
Account for P&I maintained by each Seller/Servicer an amount representing:
 
        (i) Scheduled installments of principal and interest on the Mortgage
    Loans received or advanced by the Seller/Servicer which were due on the
    first day of the current month, net of Servicing Fees due the
    Seller/Servicer and less any amounts to be withdrawn later by the Master
    Servicer from any applicable Buydown Fund Account;
 
                                       26
<PAGE>
        (ii) Proceeds of liquidations of Mortgage Loans received by the
    Seller/Servicer in the immediately preceding calendar month, with interest
    to the date of liquidation, net of Servicing Fees due the Seller/Servicer
    and less any amounts to be withdrawn later by the Master Servicer from any
    applicable Buydown Fund Account;
 
       (iii) Principal due to Payoffs received during the period from the 15th
    of the immediately preceding calendar month through the 14th of such
    calendar month; in each case with interest at the applicable Pass-Through
    Rate attributable to interest paid by the Mortgagor through the date of the
    Payoff (provided, however, that in the case of Payoffs received between the
    first day and the 14th day of any month, interest accrued from the first day
    of such month to the date of such Payoff will not be paid to the
    Certificateholders), less any amounts to be withdrawn later by the Master
    Servicer from any applicable Buydown Fund Account; and
 
       (iv) Curtailments received by the Seller/Servicer on such Mortgage Loans
    in the immediately preceding calendar month.
 
    All amounts withdrawn from the Custodial Accounts for P&I, together with any
Insurance Proceeds or Liquidation Proceeds (including any amounts paid in
respect of repurchase obligations on defective Mortgage Loans or otherwise) not
otherwise applied by Seller/Servicers and amounts withdrawn from any Buydown
Fund Account, if applicable, shall be immediately deposited into the Investment
Account.
 
    Under the Pooling Agreement for each Series of Certificates as to which the
Company will act as Master Servicer, the Master Servicer or the related
Seller/Servicer is permitted to make the following withdrawals from the Buydown
Fund Account or Custodial Account for P&I, as applicable:
 
        (i) To deposit in the Investment Account the amount necessary in order
    to supplement payments received on Buydown Loans;
 
        (ii) In the event of a Payoff of any Buydown Loan, to apply the
    remaining related Buydown Funds to reduce the required amount of such Payoff
    (or, if the Mortgagor has made a Payoff equal in amount to the total unpaid
    principal balance, to refund such remaining Buydown Funds to the person
    entitled to receive such Buydown Funds);
 
       (iii) In the event of foreclosure or liquidation of any Buydown Loan, to
    deposit the remaining related Buydown Funds in the Investment Account; and
 
       (iv) To clear and terminate the portion of any account representing
    Buydown Funds.
 
    Unless otherwise specified in the applicable Prospectus Supplement, the
Master Servicer may invest funds withdrawn from the Custodial Accounts for P&I
each month and remitted to the Master Servicer, as well as any Insurance
Proceeds, Liquidation Proceeds and Buydown Funds, for its own account and at its
own risk, for the period from the Withdrawal Date to the next Distribution Date,
or for such longer or shorter period as may be specified in the applicable
Prospectus Supplement (in each case, the "Investment Period"). Investment of
such funds shall be made through an account in the name of the Master Servicer
and the Trustee (the "Investment Account"), which shall be maintained in the
trust department of a bank acceptable to any applicable rating agency or
agencies for the Series of Certificates. The Investment Account may be a
commingled account with other similar accounts maintained by the Master Servicer
and invested for its own account; provided, that the maintenance of such a
commingled account has been approved by any applicable rating agency or agencies
for the Series of Certificates. Unless otherwise specified in the applicable
Prospectus Supplement, the investment of funds in the Investment Account shall
be limited to the investments described below.
 
    On the last day of the Investment Period, the Master Servicer will withdraw
from the Investment Account all funds due to be distributed to
Certificateholders, and shall deposit such funds, together with any Advances
required to be made by it, in the Certificate Account described below.
 
    Unless otherwise specified in the applicable Prospectus Supplement, the
investment of funds in an Investment Account shall be limited to one or more of
the following investments ("Eligible Investments") which shall in no event
mature later than the next Distribution Date:
 
                                       27
<PAGE>
        (i) Obligations of, or guaranteed as to principal and interest by, the
    United States or any agency or instrumentality thereof, when such
    obligations are backed by the full faith and credit of the United States;
 
        (ii) Repurchase agreements on obligations of, or guaranteed as to
    principal and interest by, the United States or any agency or
    instrumentality thereof, when such obligations are backed by the full faith
    and credit of the United States; provided that the unsecured obligations of
    the party agreeing to repurchase such obligations are at the time assigned
    such ratings as may be required by the applicable rating agency or agencies
    for the Series of Certificates at the date of acquisition thereof;
 
       (iii) Federal funds, certificates of deposit, time deposits and bankers'
    acceptances of any bank or trust company incorporated under the laws of the
    United States or any state thereof; provided that the debt obligations of
    such bank or trust company (or, in the case of the principal bank in a bank
    holding company system, debt obligations of the bank holding company) have
    been assigned such ratings as may be required by the applicable rating
    agency or rating agencies for the Series of Certificates at the date of
    acquisition thereof;
 
       (iv) Obligations of, or guaranteed by, any state of the United States or
    the District of Columbia receiving the highest long-term debt ratings
    available for such securities by the applicable rating agency or rating
    agencies for the Series of Certificates;
 
        (v) Commercial paper of any corporation incorporated under the laws of
    the United States or any state thereof which on the date of acquisition has
    been assigned such ratings as may be required by the applicable rating
    agency or rating agencies for the Series of Certificates; or
 
       (vi) Securities (other than stripped bonds or stripped coupons) bearing
    interest or sold at a discount that are issued by any corporation
    incorporated under the laws of the United States or any state thereof and
    rated by each applicable rating agency or rating agencies for the Series of
    Certificates in its highest long-term unsecured rating category; provided,
    however, that securities issued by any such corporation will not be
    investments to the extent that investment therein would cause the
    outstanding principal amount of securities issued by such corporation that
    are then held as part of the Custodial Account for P&I, the Investment
    Account or the Certificate Account to exceed 20% of the aggregate principal
    amount of all Eligible Investments then held in the Custodial Account for
    P&I, the Investment Account and the Certificate Account;
 
       (vii) Units of taxable money market funds or mutual funds, which funds
    have been rated by each applicable rating agency or rating agencies for the
    Series of Certificates in its highest rating category or which have been
    designated in writing by each such rating agency or rating agencies as
    Eligible Investments with respect to this definition; or
 
      (viii) such other investments bearing interest or sold at a discount the
    investment in which will not, as evidenced by a letter from each applicable
    rating agency or rating agencies for the Series of Certificates, result in
    the downgrading or withdrawal of the rating or ratings assigned to the
    Certificates by such rating agency or rating agencies.
 
    Not later than the Distribution Date for a Series of Certificates as to
which the Company will act as Master Servicer, the Master Servicer will withdraw
from the Investment Account all amounts required to be distributed on such
Distribution Date and deposit such amounts into a separate non-interest-bearing
trust account (the "Certificate Account") in the corporate trust department of
the Trustee or another depository institution acceptable to the applicable
rating agency or rating agencies.
 
    Under the Pooling Agreement for each Series of Certificates as to which the
Company will act as Master Servicer, the Master Servicer will be authorized to
make the following withdrawals from the Certificate Account:
 
        (i) To reimburse the Master Servicer or any Seller/Servicer for Advances
    out of amounts received as late payments on related Mortgage Loans or out of
    related Insurance Proceeds or Liquidation Proceeds;
 
                                       28
<PAGE>
        (ii) To reimburse the Master Servicer or any Seller/Servicer out of
    related Insurance Proceeds or Liquidation Proceeds for amounts expended by
    the Master Servicer or any Seller/ Servicer in connection with the
    restoration of property damaged by an uninsured cause or in connection with
    the liquidation of a Mortgage Loan;
 
       (iii) To pay that portion of any payment which constitutes Retained Yield
    or the Master Servicing Fee (a) deposited by a Seller/Servicer in respect of
    interest on a Mortgage Loan, (b) deposited by the Master Servicer in respect
    of interest on a Mortgage Loan or (c) deposited as Insurance Proceeds or
    Liquidation Proceeds (including amounts paid in respect of repurchase
    obligations on defective Mortgage Loans or otherwise) in respect of interest
    on a Mortgage Loan and as to which no prior withdrawals from funds deposited
    by the Master Servicer have been made; provided, however, that with respect
    to any payment of interest deposited in the Certificate Account in respect
    of a Mortgage Loan (whether paid by the Mortgagor or received as Liquidation
    Proceeds, Insurance Proceeds or otherwise) which is less than the full
    amount of interest due with respect to such Mortgage Loan, the Master
    Servicer shall withdraw from the Certificate Account as Retained Yield only
    that portion of such payment of interest that bears the same relationship to
    the total amount of such payment of interest as the Retained Yield in
    respect of such Mortgage Loan bears to the Mortgage Interest Rate for such
    Mortgage Loan;
 
       (iv) To reimburse the Master Servicer or any Seller/Servicer for Advances
    which the Master Servicer has determined to be otherwise nonrecoverable;
 
        (v) To pay any expenses which were incurred and are reimbursable
    pursuant to the Pooling Agreement; and,
 
    after making or providing for the above withdrawals,
 
       (vi) To make payments to Certificateholders and/or the Company as
    described below under "--Distributions on Certificates" and to clear and
    terminate the Certificate Account upon liquidation of all Mortgage Loans or
    other termination of the Trust Fund.
 
    The Master Servicer may also establish with the Trustee for a Series of
Certificates a Reserve Account if required to assure timely distributions of
principal and interest, as a condition to obtaining a specified rating for such
Certificates or to provide for the expenses of the Trust Fund. Any such Reserve
Account so established will be described in the applicable Prospectus
Supplement.
 
    With respect to Series of Certificates as to which the Company will not act
as Master Servicer, unless otherwise specified in the applicable Prospectus
Supplement, the Custodial Account for P&I, the Buydown Fund Account and the
Reserve Account will be established by the Servicer, and the required and
permitted deposits into and withdrawals from such accounts set forth above will
be made by the Servicer. The Servicer shall deposit any required Advances in the
Custodial Account for P&I on the Withdrawal Date. The withdrawal of funds and
their deposit into the Investment Account on the Withdrawal Date, as described
above, will also be effected by the Servicer. The Investment Account described
above will be established by the Certificate Administrator and the Trustee, and
investments of amounts therein in Eligible Investments will be directed by the
Certificate Administrator for its own account and at its own risk. The
Certificate Administrator will make the required withdrawal from the Investment
Account on the last day of the Investment Period for deposit in the Certificate
Account, as described above. Authorized withdrawals from the Certificate Account
for the purposes described above will be made by the Certificate Administrator.
Other than as set forth in this paragraph, unless the context otherwise
requires, references above to "Master Servicer" or "Seller/ Servicer", and to
"Master Servicing Fee" shall refer instead to "Servicer" and "Servicing Fee",
respectively.
 
DISTRIBUTIONS ON CERTIFICATES
 
    On each Distribution Date commencing in the month following the month in
which the Cut-Off Date occurs (or such other time as may be set forth in the
applicable Prospectus Supplement), the Trustee, the Master Servicer or the
Certificate Administrator, as applicable, acting on behalf of the Trustee or the
Paying Agent will withdraw from the Certificate Account and distribute to
 
                                       29
<PAGE>
Certificateholders of record on the applicable Record Date, and to holders of
residual interests, if any, who are entitled to receive such distributions
pursuant to the terms of the applicable Pooling Agreement, to the extent of
their entitlement thereto, an amount in the aggregate equal to the sum of:
 
        (i) All scheduled payments of principal and interest at the Pass-Through
    Rate either collected from the Mortgagors on the Mortgage Loans prior to the
    related Determination Date (as defined below) or advanced by the Master
    Servicer, the Servicer or the Seller/Servicers;
 
        (ii) Scheduled amounts of Buydown Funds respecting Buydown Loans (not
    withdrawn and remitted by the Servicer or the related Seller/Servicer, as
    applicable);
 
       (iii) All Curtailments received on the Mortgage Loans in the month prior
    to the month in which the Distribution Date occurs (the "Distribution
    Period");
 
       (iv) All Insurance Proceeds or Liquidation Proceeds received during the
    Distribution Period, together with interest at the applicable Pass-Through
    Rate to the extent described herein under "Yield Considerations--Effective
    Interest Rate"; and
 
        (v) All Payoffs received during the period from the 15th day of the
    immediately preceding calendar month through the 14th day of such calendar
    month; in each case together with interest at the applicable Pass-Through
    Rate to the extent described under "Yield Considerations-- Effective
    Interest Rate" herein;
 
    less the sum of:
 
        (a) Previously unreimbursed Advances made by the Master Servicer, the
    Seller/Servicers or the Servicer on Mortgage Loans which are considered by
    the Master Servicer or the Servicer, as the case may be, as of the
    Distribution Date to be nonrecoverable;
 
        (b) Amounts expended by the Seller/Servicers, the Master Servicer or the
    Servicer in connection with the preservation or restoration of property
    securing Mortgage Loans which have been liquidated and related liquidation
    expenses; and
 
        (c) Amounts representing other expenses of the Master Servicer, the
    Seller/Servicers or the Servicer, reimbursable pursuant to the Pooling
    Agreement.
 
    In addition, if the Master Servicer with respect to Series of Certificates
as to which the Company will act as Master Servicer, or the Servicer with
respect to Series of Certificates as to which the Company will not act as Master
Servicer, is obligated to do so under the applicable Pooling Agreement, the
Master Servicer or the Servicer, as the case may be, shall include with any such
distribution an Advance equal to principal payments and interest payments
(adjusted to the applicable Pass-Through Rate or Rates) due on the first day of
the month in which the Distribution Date occurs and not received as of the close
of business on the Withdrawal Date, subject to such Master Servicer's or
Servicer's determination that such payments are recoverable from future payments
or collections on the Mortgage Loans, any subordination feature or Insurance
Proceeds or Liquidation Proceeds. See "--Advances" below.
 
    The method of allocating the amount withdrawn from the Certificate Account
on each Distribution Date to principal and interest (or, where applicable, to
principal only or interest only) on a particular Series of Certificates will be
described in the applicable Prospectus Supplement. Distributions of interest on
each Class of Certificates will be made prior to distributions of principal
thereon. Each Class of Certificates may have a different Remittance Rate, and
each Remittance Rate may be fixed, variable or adjustable. The applicable
Prospectus Supplement will specify the Remittance Rate for each Class, or in the
case of a variable or adjustable Remittance Rate, the initial Remittance Rate
and the method for determining the Remittance Rate.
 
    On each Distribution Date for a Series of Certificates, the Trustee, the
Master Servicer or the Certificate Administrator, as applicable, on behalf of
the Trustee or the Paying Agent, as the case may be, will distribute to each
holder of record on the Record Date, an amount equal to the Percentage Interest
(as defined below) represented by the Certificate held by such holder multiplied
by the sum of the Class Principal Distribution Amount (as defined below) for
such Class and, if such Class is entitled to payments of interest on such
Distribution Date, one month's interest at the applicable Remittance
 
                                       30
<PAGE>
Rate on the principal balance or notional principal balance of such Class
specified in the applicable Prospectus Supplement, less (unless otherwise
specified in the related Prospectus Supplement) such Class's pro rata share of
the sum of (i) the shortfalls in collections of interest on Payoffs with respect
to which distribution is to be made on such Distribution Date, if any, (ii) the
amount of any deferred interest added to the principal balance of the Mortgage
Loans and/or the outstanding balance of the Certificates on the related Due
Date, (iii) one month's interest at the applicable Pass-Through Rate on the
amount of any Curtailments received on the Mortgage Loans in the month preceding
the month of the distribution and (iv) any other interest shortfalls (including,
without limitation, shortfalls arising out of application of the Soldiers' and
Sailors' Relief Act or similar legislation or regulations as in effect from time
to time) allocable to Certificateholders which are not covered by advances or
applicable credit enhancements, in each case in such amount as is allocated to
such Class on the basis set forth in the related Prospectus Supplement. The
"Percentage Interest" represented by a Certificate of a particular Class will be
equal to the percentage obtained by dividing the initial principal balance or
notional amount of such Certificate by the aggregate initial amount or notional
amount of all the Certificates of such Class. The "Class Principal Distribution
Amount" for a Class of Certificates for any Distribution Date will be the
portion, if any, of the Principal Distribution Amount (as defined in the related
Prospectus Supplement) allocable to such Class for such Distribution Date, as
described in the related Prospectus Supplement.
 
    In the case of a Series of Certificates which includes two or more Classes
of Certificates, the timing, sequential order, priority of payment or amount of
distributions in respect of principal, and any schedule or formula or other
provisions applicable to the determination thereof with respect to each such
Class shall be as provided in the related Prospectus Supplement. Distributions
in respect of principal of any Class of Certificates will be made on a pro rata
basis among all of the Certificates of such Class.
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer and except as otherwise provided in the applicable Pooling
Agreement, not later than the tenth day preceding each Distribution Date (the
"Determination Date"), the Master Servicer will furnish to the Trustee (and to
any Certificateholder upon request) a statement setting forth the aggregate
amount to be distributed on such Distribution Date to each Class of
Certificates, on account of principal and/or interest, stated separately. With
respect to Series of Certificates as to which the Company will not act as Master
Servicer, the Certificate Administrator will provide the statements described in
the preceding sentence.
 
REPORTS TO CERTIFICATEHOLDERS
 
    For each Series of Certificates, with each distribution to
Certificateholders from the Certificate Account, the Trustee, or the Master
Servicer or Certificate Administrator, as applicable, on behalf of the Trustee,
will forward to each Certificateholder a statement or statements with respect to
the related Trust Funds setting forth the information specifically described in
the related Pooling Agreement, which generally will include the following with
respect to such Series of Certificates:
 
        (i) the beginning principal balance or notional principal balance
    representing the ending balance from the prior statement;
 
        (ii) the amount, if any, of such distribution principal;
 
       (iii) the amount, if any, of such distribution allocable to interest on
    the Mortgage Loans accrued at the applicable Pass-Through Rate on the
    beginning principal balance or notional principal balance, and, with respect
    to a Series of Certificates where one or more Classes of such Series are
    subordinated in right of payment to one or more other Classes of such
    Series, the amount, if any, of any shortfall in the amount of interest and
    principal distributed;
 
       (iv) the total amount distributed;
 
        (v) the ending principal balance or notional principal balance after the
    application in (ii) above; and
 
       (vi) the then applicable Pass-Through Rate or weighted average
    Pass-Through Rate, calculated as of the close of business on the related
    Determination Date.
 
                                       31
<PAGE>
    Upon request, a Certificateholder may receive a monthly report which sets
forth (i) the amount of the distribution for such month allocable to Principal
Prepayments, miscellaneous post-liquidation collections and Conversion Fees,
(ii) Mortgage Loan delinquencies, indicating the number and aggregate principal
amount of Mortgage Loans delinquent one, two and three months, as well as the
book value of any Mortgaged Property acquired through foreclosure, deed in lieu
of foreclosure or other exercise of rights respecting the Trustee's security
interest in the Mortgage Loans, (iii) the amount of remaining coverage under any
applicable credit enhancements, stated separately, as of the close of business
on the applicable Determination Date and (iv) the sum of the Master Servicing
Fee and the aggregate Servicing Fees for the month.
 
    In addition, by the date required by applicable tax law of each year, the
Master Servicer with respect to Series of Certificates as to which the Company
will act as Master Servicer, or the Certificate Administrator with respect to
Series of Certificates as to which the Company will not act as Master Servicer,
will furnish a report to each Certificateholder of record at any time during the
preceding calendar year as to the aggregate of amounts reported pursuant to (ii)
in the second preceding paragraph above, plus information with respect to the
amount of servicing compensation for the related Mortgage Pool, the value of any
property acquired by the Trustee through abandonment or foreclosure, deferred
interest added to the principal balance or the notional principal balance of
each Class of Certificates, as applicable, and such other customary information
as the Master Servicer or Certificate Administrator, as applicable, determines
to be necessary to enable Certificateholders to prepare their tax returns for
such calendar year or, in the event such person was a Certificateholder of
record during a portion of such calendar year, for the applicable portion of
such a year.
 
ADVANCES
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer and unless otherwise stated in the applicable Prospectus
Supplement, the Master Servicer will be obligated under the Pooling Agreement to
make Advances (to the extent not previously advanced by the Seller/Servicers as
described below) in amounts sufficient to cover any deficiency between the funds
scheduled to be received on the Mortgage Loans during the Distribution Period,
and amounts withdrawn from the Custodial Accounts for P&I on each Withdrawal
Date during the Distribution Period and from any Buydown Fund Account; provided,
however, that the Master Servicer will be obligated to make such Advances only
to the extent any such Advance, in the judgment of the Master Servicer made on
the Determination Date, will be reimbursable from any applicable credit
enhancements, from Mortgagor payments or from Liquidation Proceeds or Insurance
Proceeds of the related Mortgage Loans. In connection with certain credit
enhancements, the Master Servicer may make other advances, such as to pay
insurance premiums, real estate property taxes, protection and preservation
taxes, sales expenses and foreclosure costs including court costs and reasonable
attorneys' fees in connection with a Mortgage Pool Insurance Policy, which shall
also constitute "Advances".
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer and unless otherwise stated in the applicable Prospectus
Supplement, each Seller/Servicer will be obligated to advance on the Withdrawal
Date its own funds or funds from the Custodial Account for P&I maintained by it
equal to the amount of any deficiency between the amount in such Custodial
Account for P&I on the Withdrawal Date and the amount due to be remitted to the
Master Servicer on such date. Each Seller/Servicer will advance only funds which
the Master Servicer anticipates will be ultimately reimbursable from the sources
discussed above. To the extent the Seller/Servicers make such Advances, the
Master Servicer will be relieved of its obligation, if any, to make Advances
with respect to the Mortgage Loans respecting which such amounts were advanced.
If an Advance made by any Seller/Servicer later proves to be unrecoverable, the
Master Servicer will cause such Seller/ Servicer to be reimbursed from funds in
the Certificate Account.
 
    With respect to Series of Certificates as to which the Company will not act
as Master Servicer and unless otherwise stated in the applicable Prospectus
Supplement, the Servicer will be obligated under the Pooling Agreement to
advance on the Withdrawal Date its own funds or funds from the Custodial Account
for P&I equal to the amount of any deficiency between the amount in such
Custodial Account for P&I on the Withdrawal Date and the amount due to be
remitted to the Certificate Administrator on such date. The Servicer will be
obligated to make such Advances only to the extent any such
 
                                       32
<PAGE>
Advance, in the judgment of the Servicer made on the related Determination Date,
will be reimbursable from any applicable credit enhancements, from Mortgagor
payments or from Liquidation Proceeds or Insurance Proceeds of the related
Mortgage Loans. In connection with certain credit enhancements, the Master
Servicer may make other advances, such as to pay insurance premiums, real estate
property taxes, protection and preservation taxes, sales expenses and
foreclosure costs including court costs and reasonable attorneys' fees in
connection with a Mortgage Pool Insurance Policy, which shall also constitute
"Advances".
 
COLLECTION AND OTHER SERVICING PROCEDURES
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, under the Selling and Servicing Contract each Seller/Servicer
agrees to make reasonable efforts to collect all payments called for under the
Mortgage Notes and will, consistent with the Selling and Servicing Contract, the
Pooling Agreement for any Series and any applicable credit enhancements, follow
such collection procedures as it follows or would follow with respect to
mortgage loans held for its own account which are comparable to the Mortgage
Loans. With respect to Series of Certificates as to which the Company will not
act as Master Servicer and the servicing of the Mortgage Loans will be performed
by the Servicer, the Pooling Agreement will require the Servicer to make the
same efforts to collect payments on the Mortgage Notes and follow the same
collection procedures as would be required of the Servicer if it were a
Seller/Servicer under a Selling and Servicing Contract. Consistent with the
above, each Seller/Servicer with respect to Series of Certificates as to which
the Company will act as Master Servicer, or the Servicer with respect to Series
of Certificates as to which the Company will not act as Master Servicer, may, in
its discretion, (i) waive any prepayment charge, assumption fee, late payment
charge or any other charge in connection with a Principal Prepayment on a
Mortgage Loan and (ii) only upon receiving authorization from the insurer on any
applicable Mortgage Pool Insurance Policy or Primary Insurance Policy, and with
respect to each Seller/Servicer, from the Master Servicer, arrange with a
Mortgagor a schedule for the liquidation of delinquencies running for no more
than 180 days after the first delinquent due date for payment on any Mortgage
Note. Such authorization shall be given by the Master Servicer or the Servicer
only upon determining that the coverage of such Mortgage Loan by any applicable
credit enhancement will not be affected. In the event of any such arrangement,
the Master Servicer's obligation to make Advances on the related Mortgage Loan,
if any, shall continue during the scheduled period to the extent such Advances
are not made by the Seller/Servicers.
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, the Selling and Servicing Contract with each Seller/Servicer
requires that such Seller/Servicer enforce "due-on-sale" clauses, where
applicable, with respect to the Mortgage Loans on the same basis as with loans
in its own portfolio, provided that such clause is not to be enforced if it is
unenforceable under applicable law or the terms of the related Mortgage Note or
if the coverage of any related credit enhancement would be adversely affected by
such enforcement. Subject to the above, if a Mortgaged Property has been or is
about to be conveyed by the Mortgagor, the Seller/Servicer or the Master
Servicer will be authorized to take or enter into an assumption agreement,
pursuant to which the Mortgagor remains liable under the Mortgage Note, from or
with the person to whom such Mortgaged Property has been or is about to be
conveyed. Any fees collected by a Seller/Servicer for entering into an
assumption agreement will be retained by it as additional servicing
compensation. With respect to Series of Certificates as to which the Company
will not act as Master Servicer and the servicing of the Mortgage Loans will be
performed by the Servicer, the Pooling Agreement will require the Servicer to
enforce any "due-on-sale" clause in the instances and to the extent described in
the first sentence of this paragraph, and the Servicer will be authorized to
take or enter into an assumption agreement and retain any fees collected for
entering into an assumption agreement as additional servicing compensation to
the same extent as a Seller/Servicer will be so authorized under a Selling and
Servicing Contract.
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, the Master Servicer may, or upon receiving authorization from
the Master Servicer, a Seller/Servicer may, in connection with any such
conveyance and only upon assurance that the related Mortgage Loan will continue
to be covered by any applicable credit enhancement, release the original
Mortgagor from liability upon the Mortgage Note and substitute the new Mortgagor
as liable thereon. If required by
 
                                       33
<PAGE>
law or the terms of the related Mortgage Note, the Master Servicer may allow
such release and substitution without the consent of the provider of any
applicable credit enhancement. In connection with any such assumption or
substitution, the Mortgage Interest Rate borne by the related Mortgage Note may
not be changed. With respect to Series of Certificates as to which the Company
will not act as Master Servicer and the servicing of the Mortgage Loans will be
performed by the Servicer, the Servicer may in connection with any such
conveyance release the original Mortgager from liability upon the Mortgage Note
and substitute a new Mortgagor as liable thereon in the instances and to the
extent described above in this paragraph with respect to the Master Servicer.
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, under each Selling and Servicing Contract the Seller/Servicer
is required to establish and maintain a Custodial Account for Reserves into
which Mortgagors deposit amounts sufficient to pay taxes, assessments, hazard
insurance premiums or comparable items to the extent it is consistent with such
Seller/Servicer's normal practices to collect payments from Mortgagors to cover
tax and insurance expenses. Withdrawals from the Custodial Account for Reserves
maintained for Mortgagors may be made to effect timely payment of taxes,
assessments and hazard insurance premiums or comparable items, to reimburse the
Seller/Servicer out of related assessments for maintaining hazard insurance, to
refund to Mortgagors amounts determined to be overages, to pay interest to
Mortgagors on balances in the Custodial Account for Reserves, if required, to
repair or otherwise protect the Mortgaged Property and to clear and terminate
the Custodial Account for Reserves. Each Seller/ Servicer is solely responsible
for administration of the Custodial Account for Reserves and is expected to make
Advances to such account when a deficiency exists therein. With respect to
Series of Certificates as to which the Company will not act as Master Servicer
and the servicing of the Mortgage Loans will be performed by the Servicer, the
Servicer will be required to establish and maintain a Custodial Account for
Reserves and to make Advances to such account, and will be authorized to make
withdrawals from the Custodial Account for Reserves, in the instances and to the
extent a Seller/ Servicer would be so required and authorized under a Selling
and Servicing Contract.
 
SERVICING COMPENSATION AND PAYMENT OF EXPENSES
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, the Seller/Servicers' primary compensation for their servicing
activities will come from the payment to them or the retention by them, of an
amount equal to the Servicing Fee for each Mortgage Loan. The Master Servicer's
primary compensation for supervising the mortgage servicing and advancing
certain expenses of a Mortgage Pool will come from the payment to it, of an
amount equal to the Master Servicing Fee with respect to each Mortgage Loan in
such Mortgage Pool. The Master Servicing Fee and the Servicing Fee with respect
to each payment of interest received on a Mortgage Loan will equal one-twelfth
of the annual Master Servicing Fee or Servicing Fee annual percentage, as
applicable, set forth in the Pooling Agreement multiplied by the outstanding
principal balance of such Mortgage Loan during the month for which such amount
is computed. In addition to the Servicing Fee and Master Servicing Fee, the
Company or a Seller may retain as its Retained Yield the right to a portion of
the interest payable on each Mortgage Loan calculated by subtracting the
applicable Pass-Through Rate and related Servicing Fee and Master Servicing Fee
from the applicable Mortgage Interest Rate.
 
    With respect to Series of Certificates as to which the Company will not act
as Master Servicer and the servicing of the Mortgage Loans will be performed by
the Servicer, the Servicer's primary compensation for its servicing activities
will come from the payment to it or its retention, with respect to each interest
payment on a Mortgage Loan, of an amount equal to the Servicing Fee for such
Mortgage Loan. The Servicing Fee with respect to each payment of interest
received on a Mortgage Loan will equal one-twelfth of the Servicing Fee annual
percentage set forth in the Pooling Agreement multiplied by the outstanding
principal balance of such Mortgage Loan during the month for which such amount
is computed. In addition to the Servicing Fee, the Company or a Seller may
retain as its Retained Yield the right to a portion of the interest payable on
each Mortgage Loan calculated by subtracting the related Servicing Fee, the
Certificate Administrator Fee and the Remittance Rate from the applicable
Mortgage Interest Rate.
 
    With respect to Series of Certificates as to which the Company will not act
as Master Servicer and the servicing of the Mortgage Loans will be performed by
the Servicer, the Certificate Administrator's
 
                                       34
<PAGE>
compensation for its administrative services will come from the payment to it,
with respect to each interest payment on a Mortgage Loan, of an amount equal to
the Certificate Administrator Fee for such Mortgage Loan. The Certificate
Administrator Fee with respect to each payment of interest received on a
Mortgage Loan will equal one-twelfth of the annual Certificate Administrator Fee
annual percentage set forth in the Pooling Agreement multiplied by the
outstanding principal balance of such Mortgage Loan during the month for which
such amount is computed, subject to any minimum fee as will be set forth in the
applicable Prospectus Supplement.
 
    As principal payments are made on each Mortgage Loan, the outstanding
principal balance of the Mortgage Loans will decline, and thus compensation to
the Seller/Servicers and the Master Servicer, or to the Servicer and the
Certificate Administrator with respect to Series of Certificates for which the
Company will not act as Master Servicer, and any Retained Yield will decrease as
the Mortgage Loans amortize (subject to any minimum levels of such compensation
set forth in the applicable Prospectus Supplement). Principal Prepayments and
liquidations of Mortgage Loans prior to maturity will also cause servicing
compensation to the Seller/Servicers and the Master Servicer, or to the Servicer
and the Certificate Administrator, as applicable, and any Retained Yield to
decrease (subject to any minimum levels of such compensation set forth in the
applicable Prospectus Supplement).
 
    In addition to their primary compensation, the Seller/Servicers or the
Servicer, as applicable, will retain all prepayment fees, assumption fees and
late payment charges, to the extent collected from Mortgagors. The
Seller/Servicers' or the Servicer's income from such charges will depend upon
their origination and servicing policies.
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, the Master Servicer will pay all expenses incurred in
connection with its activities as Master Servicer (subject to limited
reimbursement as described below), which, unless otherwise specified in the
applicable Prospectus Supplement, will include payment of the fees and
disbursements of the Trustee, payment of premiums of any Mortgage Pool Insurance
Policy, Special Hazard Insurance Policy, certificate insurance policy, Fraud
Bond or Bankruptcy Bond or the costs of obtaining or maintaining any Letter of
Credit or Reserve Fund and payment of expenses incurred in connection with
distributions and reports to Certificateholders of each Series.
 
    With respect to Series of Certificates as to which the Company will not act
as Master Servicer and the servicing of the Mortgage Loans will be performed by
the Servicer, the Servicer will pay certain expenses incurred in connection with
its activities as Servicer (subject to limited reimbursement as described
below), which, unless otherwise specified in the applicable Prospectus
Supplement, will include payment of premiums of any Mortgage Pool Insurance
Policy, Special Hazard Insurance Policy, certificate insurance policy, Fraud
Bond or Bankruptcy Bond or the costs of maintaining any Letter of Credit or
Reserve Fund. The Certificate Administrator will pay the fees and disbursements
of the Trustee.
 
    As set forth in the preceding section, the Master Servicer and the
Seller/Servicers, or the Servicer, as applicable, are entitled to reimbursement
for certain expenses incurred by them in connection with the liquidation of
defaulted Mortgage Loans. Certificateholders of such Series will suffer no loss
by reason of such expenses to the extent claims are paid under any applicable
credit enhancements. In the event, however, that claims are not paid under such
policies or alternative coverages, or if coverage has been exhausted,
Certificateholders of such Series will suffer a loss to the extent that the
proceeds of liquidation of a defaulted Mortgage Loan, after reimbursement of the
Master Servicer's and the Seller/Servicer's expenses, or the Servicer's
expenses, as applicable, are less than the principal balance of such Mortgage
Loan. In addition, the Master Servicer and the Seller/Servicers, or the
Servicer, as applicable, are entitled to reimbursement of expenditures incurred
by them in connection with the restoration of a damaged Mortgaged Property, such
right of reimbursement being prior to the rights of Certificateholders to
receive any related Insurance Proceeds or Liquidation Proceeds.
 
EVIDENCE AS TO COMPLIANCE
 
    Except as may be specified in the applicable Prospectus Supplement, each
Pooling Agreement will provide that on or before April 30 of each year,
beginning on the first April 30 that is at least six months after the Cut-Off
Date, one or more firms of independent public accountants will furnish
statements to the Trustee to the effect that, in connection with such firm's
examination of the
 
                                       35
<PAGE>
financial statements of the Master Servicer or the Servicer, as applicable, as
of the previous December 31, nothing came to such firm's attention that
indicated that the Master Servicer or the Servicer, as applicable, was not in
compliance with specified sections of the Pooling Agreement, except for (i) such
exceptions as such firm believes to be immaterial and (ii) such other exceptions
as are set forth in such statement.
 
    Except as may be provided in the applicable Prospectus Supplement, each
Pooling Agreement will also provide for delivery to the Trustee of an annual
statement signed by an officer of the Master Servicer or the Servicer, as
applicable, to the effect that, based on a review of the Master Servicer's or
the Servicer's activities during the preceding calendar year, to the best of
such officer's knowledge the Master Servicer or the Servicer, as applicable, has
fulfilled its obligations under the Pooling Agreement throughout the preceding
year or, if there has been a default in the fulfillment of any such obligations,
specifying each such default and the nature and status thereof.
 
CERTAIN MATTERS REGARDING THE MASTER SERVICER, THE
  SERVICER, THE CERTIFICATE ADMINISTRATOR AND THE COMPANY
 
    Except as may otherwise be specified in the applicable Prospectus
Supplement, the Pooling Agreement for each Series will provide that the Company
may not resign from its obligations and duties thereunder as Master Servicer or
Certificate Administrator, as applicable, or that the Servicer, where
applicable, may not resign from its obligations and duties thereunder, except
upon determination that its duties thereunder are no longer permissible under
applicable law. No such resignation will become effective until the Trustee or a
successor has assumed the Company's master servicing obligations and duties, or,
where applicable, the Servicer's obligations and duties, under such Pooling
Agreement.
 
    The Pooling Agreement for each Series will provide that neither the Company
nor the Master Servicer, or that, where applicable, neither the Servicer nor the
Certificate Administrator, nor any director, officer, employee or agent of the
Company, the Master Servicer, the Servicer and the Certificate Administrator
(where applicable) (the "Indemnified Parties") will be under any liability to
the Trust Fund or the Certificateholders or the Trustee, any Seller/Servicer or
others for any action taken by any Indemnified Party, any Seller/Servicer or the
Trustee in good faith pursuant to the Pooling Agreement, or for errors in
judgment; provided, however, that neither the Company, the Master Servicer, the
Servicer nor the Certificate Administrator nor any such person will be protected
against any liability which would otherwise be imposed by reason of willful
misfeasance, bad faith or gross negligence in the performance of duties or by
reason of reckless disregard of obligations and duties thereunder. The Pooling
Agreement relating to each such Series will further provide that any Indemnified
Party is entitled to indemnification by the Trust Fund and will be held harmless
against any loss, liability or expense incurred in connection with any legal
action relating to the Pooling Agreement or the Certificates, other than any
loss, liability or expense related to any specific Mortgage Loan or Mortgage
Loans (except any such loss, liability or expense otherwise reimbursable
pursuant to the Pooling Agreement) and any loss, liability or expense incurred
by reason of willful misfeasance, bad faith or gross negligence in the
performance of duties thereunder or by reason of reckless disregard of
obligations and duties thereunder. In addition, the Pooling Agreement for each
such Series will provide that neither the Company nor the Master Servicer or,
where applicable, neither the Servicer nor the Certificate Administrator, is
under any obligation to appear in, prosecute or defend any legal action which is
not incidental to its responsibilities under the Pooling Agreement and which in
its opinion may involve it in any expense or liability. The Company or the
Master Servicer or, where applicable, the Servicer or the Certificate
Administrator, may, however, in its discretion, undertake any such action which
it may deem necessary or desirable with respect to the Pooling Agreement and the
rights and duties of the parties thereto and the interests of the
Certificateholders thereunder. In such event, the legal expenses and costs of
such action and any liability resulting therefrom will be expenses, costs and
liabilities of the Trust Fund, and the Company or the Master Servicer or, where
applicable, the Servicer or the Certificate Administrator, will be entitled to
be reimbursed therefor and to charge the Certificate Account.
 
    Any person into which the Master Servicer, the Servicer or the Certificate
Administrator may be merged, converted or consolidated, or any person resulting
from any merger, conversion or consolidation to which the Master Servicer, the
Servicer or the Certificate Administrator is a party, or
 
                                       36
<PAGE>
any person succeeding to the business of the Master Servicer, the Servicer or
the Certificate Administrator, will be the successor of the Master Servicer, the
Servicer or the Certificate Administrator, respectively, under the Pooling
Agreement.
 
EVENTS OF DEFAULT
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, events of Default under the Pooling Agreement for each such
Series, unless otherwise specified in the applicable Prospectus Supplement, will
include, without limitation, (i) any failure by the Master Servicer to make a
required deposit to the Certificate Account or, if the Master Servicer is the
Paying Agent, to distribute to Certificateholders of any Class any required
payment which continues unremedied for ten days after the giving of written
notice of such failure to the Master Servicer by the Trustee, or to the Master
Servicer and the Trustee by the holders of Certificates for that Series
evidencing interests aggregating not less than 25% of the Trust Fund, as
determined in the manner set forth in such Pooling Agreement; (ii) any failure
on the part of the Master Servicer duly to observe or perform in any material
respects any other of the covenants or agreements on the part of the Master
Servicer contained in the Certificates for that Series or in such Pooling
Agreement which continues unremedied for 60 days after the giving of written
notice of such failure to the Master Servicer by the Trustee, or to the Master
Servicer and the Trustee by the holders of Certificates for that Series
evidencing interests aggregating not less than 25% of the Trust Fund, as
determined in the manner set forth in such Pooling Agreement; and (iii) certain
events of insolvency, readjustment of debt, marshalling of assets and
liabilities or similar proceedings and certain actions by the Master Servicer
indicating insolvency, reorganization or inability to pay its obligations. With
respect to Series of Certificates as to which the Company will not act as Master
Servicer, the Events of Default under the Pooling Agreement for each such
Series, unless otherwise specified in the applicable Prospectus Supplement, will
be the same failures by or conditions of the Servicer or the Certificate
Administrator as will constitute Events of Default by the Master Servicer under
the Pooling Agreement for each Series of Certificates for which the Company will
act as Master Servicer, except that an Event of Default created by a failure of
the Master Servicer to make a required deposit to the Certificate Account
referred to in clause (i) of the immediately prior sentence will instead be the
failure of the Servicer to make a required deposit to the Investment Account on
the Withdrawal Date.
 
RIGHTS UPON EVENT OF DEFAULT
 
    As long as an Event of Default under the Pooling Agreement for any Series
remains unremedied, the Trustee or holders of Certificates for that Series
evidencing interests aggregating not less than 25% of the Trust Fund, as
determined in the manner set forth in such Pooling Agreement, may terminate all
of the rights and obligations of the Master Servicer, the Servicer or the
Certificate Administrator, as applicable, under such Pooling Agreement and in
and to the Trust Fund, whereupon the Trustee will succeed to all the
responsibilities, duties and liabilities of the Master Servicer, the Servicer or
the Certificate Administrator, as applicable, under such Pooling Agreement and
will be entitled to similar compensation arrangements and limitations on
liability. In the event that the Trustee is unwilling or unable so to act, it
may appoint or petition a court of competent jurisdiction for the appointment of
a housing and home finance institution with a net worth of at least $10,000,000
to act as successor to the Master Servicer, the Servicer or the Certificate
Administrator, as applicable, under such Pooling Agreement. Pending any such
appointment, the Trustee is obligated to act in such capacity. In the event the
Trustee acts as successor to the Master Servicer or the Servicer, the Trustee
will be obligated to make Advances unless it is prohibited by law from doing so.
The Trustee and such successor may agree upon the compensation to be paid, which
in no event may be greater than the compensation to the Company, as initial
Master Servicer, or with respect to a Series of Certificates as to which the
Company will not act as Master Servicer, to the Servicer named in the applicable
Prospectus Supplement or the Certificate Administrator, as applicable, under
such Pooling Agreement. Subject to certain limitations, holders of Certificates
for a Series evidencing interests aggregating not less than 25% of the Trust
Fund, as determined in the manner set forth in the Pooling Agreement for that
Series, may direct the action of the Trustee in pursuing remedies and exercising
powers under such Pooling Agreement.
 
    No Certificateholder of any Series will have any right under the applicable
Pooling Agreement to institute any proceeding with respect to such Pooling
Agreement unless such Certificateholder
 
                                       37
<PAGE>
previously has given to the Trustee written notice of default and unless the
holders of Certificates for that Series evidencing interests aggregating not
less than 25% of the Trust Fund, as determined in the manner set forth in such
Pooling Agreement, have made written request upon the Trustee to institute such
proceeding in its own name as Trustee thereunder and have offered to the Trustee
reasonable indemnity and the Trustee for 60 days has neglected or refused to
institute any such proceeding. However, the Trustee is under no obligation to
exercise any of the trusts or powers vested in it by the Pooling Agreement for
any Series or to make any investigation of matters arising thereunder or to
institute, conduct or defend any litigation thereunder or in relation thereto at
the request, order or direction of any of the Certificateholders, unless such
Certificateholders have offered to the Trustee reasonable security or indemnity
against the costs, expenses and liabilities which may be incurred therein or
thereby.
 
AMENDMENT
 
    The Pooling Agreement for each Series may be amended by the Company and the
Trustee, with respect to Series of Certificates as to which the Company will act
as Master Servicer, and by the Company, the Servicer, the Certificate
Administrator and the Trustee with respect to Series of Certificates as to which
the Company will not act as Master Servicer, without the consent of any of the
Certificateholders covered by such Pooling Agreement, (i) to cure any ambiguity,
(ii) to correct or supplement any provision therein which may be inconsistent
with any other provision therein, (iii) to comply with any requirements imposed
by the Internal Revenue Code of 1986, as amended (the "Code") or any regulations
thereunder, including provisions to such extent as shall be necessary to
maintain the qualification of the Trust Fund as a REMIC or to avoid or minimize
the risk of imposition of any tax on the related Trust Fund, and (iv) to correct
the description of any property at any time included in the Trust Fund, or to
assure conveyance to the Trustee of any property included in the Trust Fund. The
Pooling Agreement for each Series may also be amended by the Company and the
Trustee, with respect to Series of Certificates as to which the Company will act
as Master Servicer, and by the Company, the Servicer, the Certificate
Administrator and the Trustee with respect to Series of Certificates as to which
the Company will not act as Master Servicer, with the consent of the holders of
Certificates for that Series evidencing interests aggregating not less than 66%
of the Trust Fund, as determined in the manner set forth in such Pooling
Agreement, for the purpose of adding any provisions to or changing in any manner
or eliminating any of the provisions of such Pooling Agreement or of modifying
in any manner the rights of the holders of Certificates of that Series;
provided, however, that no such amendment may (i) reduce in any manner the
amount of, or delay the timing of, payments received on Mortgage Loans which are
required to be distributed in respect of any Certificate without the consent of
the holder of such Certificate, or (ii) reduce the aforesaid percentage of
Certificates, the holders of which are required to consent to any such amendment
without the consent of the holders of all Certificates of such Series then
outstanding.
 
    The Prospectus Supplement for a particular Series may describe other or
different provisions concerning conditions to the amendment of the related
Pooling Agreement.
 
LIST OF CERTIFICATEHOLDERS
 
    With respect to Series of Certificates as to which the Company will act as
Master Servicer, upon written request of the Trustee, the Master Servicer will
provide to the Trustee within 30 days after the receipt of such request a list
of the names and addresses of all Certificateholders of record of a particular
Series or Class as of the most recent Record Date for payment of distributions
to Certificateholders of that Series or Class. Upon written request of three or
more Certificateholders of record of such a Series of Certificates, for purposes
of communicating with other Certificateholders with respect to their rights
under the Pooling Agreement for such Series, the Trustee will afford such
Certificateholders access during business hours to the most recent list of
Certificateholders of that Series held by the Trustee. If such list is as of a
date more than 90 days prior to the date of receipt of such Certificateholders'
request, the Trustee shall promptly request from the Master Servicer a current
list and will afford such requesting Certificateholders access to such list
promptly upon receipt. With respect to Series of Certificates as to which the
Company will not act as Master Servicer, the Company, as Certificate
Administrator, will provide the list of names and addresses of the
Certificateholders described above in the same manner as so described.
 
                                       38
<PAGE>
TERMINATION
 
    The obligations created by the Pooling Agreement for each Series will
terminate upon the occurrence of both (i) the later of the maturity or other
liquidation of the last Mortgage Loan subject thereto and the disposition of all
property acquired upon foreclosure of any Mortgage Loan and (ii) the payment to
Certificateholders of each Class, if any, of that Series of all amounts held on
behalf of such Certificateholders and required to be paid to them pursuant to
such Pooling Agreement. The Pooling Agreement for each Series will permit, but
not require, the Company to repurchase from the Trust Fund for such Series all
remaining Mortgage Loans at a price equal to the unpaid principal amount thereof
or the Trust Fund's adjusted basis in the Mortgage Loans, as described in the
related Prospectus Supplement, in either case together with interest at the
applicable Mortgage Interest Rates (which will generally be passed through to
Certificateholders at the applicable Pass-Through Rates). The exercise of such
right will effect early retirement of the Certificates of such Series, but the
Company's right so to repurchase is subject to the aggregate principal balances
of the Mortgage Loans at the time of repurchase being less than the percentage
specified in the related Prospectus Supplement of the aggregate principal amount
of the Mortgage Loans underlying the Certificates of such Series as of the
Cut-Off Date. In no event, however, will the trust created by any Pooling
Agreement continue beyond the expiration of 21 years from the death of the
survivor of the issue of the person named in such Pooling Agreement. For each
Series, the Trustee will give written notice of termination of the Pooling
Agreement to each Certificateholder, and the final distribution will be made
only upon surrender and cancellation of the Certificates at an office or agency
specified in the notice of termination.
 
THE TRUSTEE
 
    The Trustee under each Pooling Agreement will be named in the related
Prospectus Supplement. The bank or trust company serving as Trustee may have
normal banking relationships with the Company and/or its affiliates. The Trustee
will have combined capital and surplus of not less than $50 million.
 
    The Trustee under each Pooling Agreement may resign at any time, in which
event the Company will be obligated to appoint a successor Trustee. The Company
may also remove the Trustee if the Trustee ceases to be eligible to continue as
such under the applicable Pooling Agreement or if the capital and surplus of the
Trustee is reduced below $50 million. Upon becoming aware of such circumstances,
the Company will be obligated to appoint a successor Trustee for the related
Series. The Trustee may also be removed at any time by holders of Certificates
of a Series evidencing more than 50% of the aggregate undivided interests in the
related Trust Fund. Any resignation or removal of the Trustee and appointment of
a successor Trustee will not become effective until acceptance of the
appointment by the successor Trustee.
 
             PRIMARY INSURANCE, FHA MORTGAGE INSURANCE, VA MORTGAGE
                 GUARANTY, HAZARD INSURANCE; CLAIMS THEREUNDER
 
    As set forth below, a Mortgage Loan may be required to be covered by a
hazard insurance policy and either an FHA Insurance Policy, a VA Guaranty or a
Primary Insurance Policy. The following is only a brief description of such
coverage and does not purport to describe all of the characteristics of each
type of insurance. Such insurance is subject to underwriting and approval of
individual Mortgage Loans by the respective insurers and guarantors. In some
cases, however, the issuer of the insurance or guaranty may delegate
underwriting authority to the originator of the Mortgage Loan. The descriptions
of any insurance coverage in this Prospectus or any Prospectus Supplement do not
purport to be complete and are qualified in their entirety by reference to such
forms of policies, and to such statutes or regulations as may be applicable.
 
PRIMARY INSURANCE
 
    Unless otherwise specified in the applicable Prospectus Supplement, each
Mortgage Loan with a loan-to-value ratio at origination and at the Cut-Off Date
greater than 80% will be covered by a Primary Insurance Policy providing
insurance coverage against default on such Mortgage Loan, in general, of up to
25% of the principal balance of such Mortgage Loan with maintenance requirements
in certain cases for the remaining term of such Mortgage Loan, but at least
until the loan-to-value
 
                                       39
<PAGE>
ratio drops to 80%. Conversely, Mortgage Loans with lower loan-to-value ratios
(up to approximately 80%) may not be covered by any Primary Insurance Policies.
Applicable state laws may in some instances limit the maximum coverage which may
be obtained with respect to certain Mortgage Loans. Any such policy will be
issued by a Qualified Insurer.
 
    While the terms and conditions of the Primary Insurance Policies will
differ, each Primary Insurance Policy will in general provide substantially the
following coverage. The amount of the loss as calculated under a Primary
Insurance Policy covering a Mortgage Loan (herein referred to as the "Loss")
will generally consist of the unpaid principal balance of such Mortgage Loan and
accrued and unpaid interest thereon and reimbursement of certain expenses, less
(i) rents or other payments collected or received by the insured (other than the
proceeds of hazard insurance) that are derived from the related Mortgaged
Property, (ii) hazard insurance proceeds in excess of the amount required to
restore such Mortgaged Property and which have not been applied to the payment
of the Mortgage Loan, (iii) certain amounts expended by the insured but not
approved by the insurer, (iv) claim payments previously made on such Mortgage
Loan and (v) unpaid premiums and certain other amounts.
 
    The issuer of a Primary Insurance Policy will generally be required to pay
either: (i) the insured percentage of the Loss; (ii) the entire amount of the
Loss, after receipt by the insurer of good and merchantable title to, and
possession of, the Mortgaged Property; or (iii) at the option of the insurer
under certain Primary Insurance Policies, the sum of the delinquent monthly
payments plus any advances made by the insured, both to the date of the claim
payment and, thereafter, monthly payments in the amount that would have become
due under the Mortgage Loan if it had not been discharged plus any advances made
by the insured until the earlier of (a) the date the Mortgage Loan would have
been discharged in full if the default had not occurred or (b) an approved sale.
 
    As conditions precedent to the filing or payment of a claim under a Primary
Insurance Policy, in the event of default by the Mortgagor, the insured will
typically be required, among other things, to: (i) advance or discharge (a)
hazard insurance premiums and (b) as necessary and approved in advance by the
insurer, real estate taxes, protection and preservation expenses and foreclosure
and related costs; (ii) in the event of any physical loss or damage to the
Mortgaged Property, have the Mortgaged Property restored to at least its
condition at the effective date of the Primary Insurance Policy (ordinary wear
and tear excepted); and (iii) tender to the insurer good and merchantable title
to, and possession of, the Mortgaged Property. If any Advance to be made
(including expenses to be paid) by the Master Servicer as a condition for
coverage of a loss by a Primary Insurance Policy is not so made by the Master
Servicer because the such Advance has been determined to be nonrecoverable, then
such loss will be allocated to the Certificateholders. See "Description of
Certificates--Advances".
 
    For any Certificates offered hereunder, the Master Servicer will cause each
Servicer to maintain, or with respect to a Series of Certificates as to which
the Company will not act as Master Servicer, the Servicer will maintain, in full
force and effect and to the extent coverage is available a Primary Insurance
Policy with regard to each Mortgage Loan for which such coverage is required
under the standard described above, provided that such Primary Insurance Policy
was in place as of the Cut-Off Date and the Company had knowledge of such
Primary Insurance Policy. With respect to Series of Certificates as to which the
Company will act as Master Servicer, in the event that the Master Servicer
learns that a Mortgage Loan had a loan-to-value ratio at origination and as of
the Cut-Off Date in excess of 80% and was not the subject of a Primary Insurance
Policy (and was not included in any exception to such standard disclosed in the
related Prospectus Supplement), then the Master Servicer is required to use its
reasonable efforts to obtain and maintain a Primary Insurance Policy to the
extent that such a policy is obtainable at a reasonable price. With respect to
Series of Certificates as to which the Company will not act as Master Servicer,
in the event the Servicer learns of the lack of a Primary Insurance Policy
described in the preceding sentence, the Servicer shall notify the Trustee who
shall require the Seller to obtain a Primary Insurance Policy, repurchase the
Mortgage Loan or substitute a mortgage loan for the applicable Mortgage Loan.
The Master Servicer or the Servicer, as applicable, will not cancel or refuse to
renew any such Primary Insurance Policy in effect at the time of the initial
issuance of a Series of Certificates that is required to be kept in force under
the applicable Pooling Agreement unless, in the event that such Series of
Certificates was rated at the time of issuance, the replacement Primary
Insurance Policy from such cancelled or non-renewed policy is
 
                                       40
<PAGE>
maintained with an insurer whose claims-paying ability is acceptable to the
rating agency or agencies that rated such Series of Certificates for mortgage
pass-through certificates having a rating equal to or better than the
then-current ratings of such series of Certificates.
 
    Evidence of each Primary Insurance Policy will be provided to the Trustee
simultaneously with the transfer to the Trustee of the related Mortgage Loan.
With respect to Series of Certificates as to which the Company will act as
Master Servicer, under the Selling and Servicing Contract each Seller/ Servicer,
on behalf of itself, the Company, the Master Servicer, the Trustee and the
Certificateholders, will be required to present claims to the insurer under any
Primary Insurance Policy and take such reasonable steps as are necessary to
permit recovery thereunder with respect to defaulted Mortgage Loans. Amounts
collected by a Seller/Servicer under such Primary Insurance Policy shall be
deposited in the Custodial Account for P&I maintained by such Seller/Servicer on
behalf of the Company, the Master Servicer, the Trustee and the
Certificateholders. The Master Servicer will agree to cause each Seller/Servicer
not to cancel or refuse to renew any Primary Insurance Policy required to be
kept in force by the Pooling Agreement. With respect to Series of Certificates
as to which the Company will not act as Master Servicer, under the Pooling
Agreement the Servicer will agree not to cancel or refuse to renew any Primary
Insurance Policy and will be required to present claims to the insurer under any
such Primary Insurance Policy, take steps to permit recovery under any such
Primary Insurance Policy and deposit amounts collected thereunder in the
Custodial Account for P&I to the same extent as a Seller/Servicer will be so
required under a Selling and Servicing Contract.
 
    See "Description of Credit Enhancements--The Fraud Bond" for a discussion of
the possible effect of fraudulent conduct or negligence by the Seller, the
Seller/Servicer or the Mortgagor with respect to a Mortgage Loan on the coverage
of a Primary Insurance Policy.
 
FHA MORTGAGE INSURANCE
 
    The National Housing Act of 1934, as amended (the "Housing Act"), authorizes
various FHA mortgage insurance programs. Some of the Mortgage Loans may be
insured under either Section 203(b), Section 234 or Section 235 of the Housing
Act. Under Section 203(b), FHA insures mortgage loans of up to 30 years'
duration for the purchase of one- to four-family dwelling units. Mortgage loans
for the purchase of condominium units are insured by FHA under Section 234.
Loans insured under these programs must bear interest at a rate not exceeding
the maximum rate in effect at the time the loan is made, as established by the
United States Department of Housing and Urban Development ("HUD"), and may not
exceed specified percentages of the lesser of the appraised value of the
property and the sales price, less seller paid closing costs for the property,
up to certain specified maximums. In addition, FHA imposes initial investment
minimums and other requirements on mortgage loans insured under the Section
203(b) and Section 234 programs.
 
    Under Section 235, assistance payments are paid by HUD to the mortgagee on
behalf of eligible mortgagors for as long as the mortgagors continue to be
eligible for the payments. To be eligible, a mortgagor must be part of a family,
must have income within the limits prescribed by HUD at the time of initial
occupancy, must occupy the property and must meet requirements for
recertification at least annually.
 
    The regulations governing these programs provide that insurance benefits are
payable either (i) upon foreclosure (or other acquisition of possession) and
conveyance of the mortgaged premises to HUD or (ii) upon assignment of the
defaulted mortgage loan to HUD. The FHA insurance that may be provided under
these programs upon conveyance of the home to HUD is equal to 100% of the
outstanding principal balance of the mortgage loan, plus accrued interest, as
described below, and certain additional costs and expenses. When entitlement to
insurance benefits results from assignment of the mortgage loan to HUD, the
insurance payment is computed as of the date of the assignment and includes the
unpaid principal amount of the mortgage loan plus mortgage interest accrued and
unpaid to the assignment date.
 
    When entitlement to insurance benefits results from foreclosure (or other
acquisition of possession) and conveyance, the insurance payment is equal to the
unpaid principal amount of the mortgage loan, adjusted to reimburse the
mortgagee for certain tax, insurance and similar payments made by it and to
deduct certain amounts received or retained by the mortgagee after default, plus
reimbursement not to exceed two-thirds of the mortgagee's foreclosure costs.
 
                                       41
<PAGE>
VA MORTGAGE GUARANTY
 
    The Servicemen's Readjustment Act of 1944, as amended, permits a veteran
(or, in certain instances, his or her spouse) to obtain a mortgage loan guaranty
by the VA covering mortgage financing of the purchase of a one-to four-family
dwelling unit to be occupied as the veteran's home at an interest rate not
exceeding the maximum rate in effect at the time the loan is made, as
established by HUD. The program has no limit on the amount of a mortgage loan,
requires no down payment from the purchaser and permits the guaranty of mortgage
loans with terms limited by the estimated economic life of the property, up to
30 years. The maximum guaranty that may be issued by the VA under this program
is 50% of the original principal amount of the mortgage loan up to a certain
dollar limit established by the VA. The loan-to-value ratios allowed for
VA-guaranteed loans are set forth in the FNMA Seller's Guide. The liability on
the guaranty is reduced or increased pro rata with any reduction or increase in
the amount of indebtedness, but in no event will the amount payable on the
guaranty exceed the amount of the original guaranty. Notwithstanding the dollar
and percentage limitations of the guaranty, a mortgagee will ordinarily suffer a
monetary loss only where the difference between the unsatisfied indebtedness and
the proceeds of a foreclosure sale of mortgaged premises is greater than the
original guaranty as adjusted. The VA may, at its option, and without regard to
the guaranty, make full payment to a mortgagee of the unsatisfied indebtedness
on a mortgage upon its assignment to the VA.
 
    Since there is no limit imposed by the VA on the principal amount of a
VA-guaranteed mortgage loan but there is a limit on the amount of the VA
guaranty, additional coverage under a Primary Insurance Policy may be required
by the Company for VA loans in excess of certain amounts. The amount of any such
additional coverage will be set forth in the related Prospectus Supplement.
 
HAZARD INSURANCE
 
    Unless otherwise specified in the applicable Prospectus Supplement, each
Seller/Servicer with respect to Series of Certificates as to which the Company
will act as Master Servicer, or the Servicer with respect to Series of
Certificates as to which the Company will not act as Master Servicer, will cause
to be maintained for each Mortgage Loan (other than Cooperative Loans and
Mortgage Loans secured by condominium apartments) that it services a hazard
insurance policy providing for no less than the coverage of the standard form of
fire insurance policy with extended coverage customary in the state in which the
Mortgaged Property is located. Such coverage will be in an amount not less than
the maximum insurable value of the Mortgaged Property or the original principal
balance of such Mortgage Loan, whichever is less. As set forth above, all
amounts collected by the Master Servicer or a Seller/Servicer, or the Servicer,
as applicable, under any hazard policy (except for amounts to be applied to the
restoration or repair of the Mortgaged Property or released to the Mortgagor in
accordance with the Seller/Servicer's or the Servicer's normal servicing
procedures) will be deposited in the Custodial Account for P&I. In the event
that the Master Servicer or the Seller/Servicer, or the Servicer, as applicable,
maintains a blanket policy insuring against hazard losses on all of the Mortgage
Loans, it shall conclusively be deemed to have satisfied its obligation relating
to the maintenance of hazard insurance. Such blanket policy may contain a
deductible clause, in which case the Master Servicer or the Seller/Servicer, or
the Servicer, as applicable, will deposit in the Custodial Account for P&I or
the Certificate Account all sums which would have been deposited therein but for
such clause. The Master Servicer and each of the Seller/Servicers with respect
to Series of Certificates as to which the Company will act as Master Servicer,
or the Servicer with respect to Series of Certificates as to which the Company
will not act as Master Servicer, are required to maintain a fidelity bond and
errors and omissions policy with respect to officers and employees which provide
coverage against losses which may be sustained as a result of an officer's or
employee's misappropriation of funds or errors and omissions in failing to
maintain insurance, subject to certain limitations as to amount of coverage,
deductible amounts, conditions, exclusions and exceptions in such form and
amount as specified in the Servicing Contract or the Pooling Agreement, as
applicable.
 
    In general, the standard form of fire and extended coverage policy covers
physical damage to or destruction of the improvements on the property by fire,
lightning, explosion, smoke, windstorm and hail, and riot, strike and civil
commotion, subject to the conditions and exclusions particularized in each
policy. Although the policies relating to the Mortgage Loans will be
underwritten by different insurers under different state laws in accordance with
different applicable state forms and therefore
 
                                       42
<PAGE>
will not contain identical terms and conditions, the basic terms thereof are
dictated by respective state laws, and most such policies typically do not cover
any physical damage resulting from the following: war, revolution, governmental
actions, floods and other water-related causes, earth movement (including
earthquakes, landslides and mud flows), nuclear reactions, wet or dry rot,
vermin, rodents, insects or domestic animals, theft and, in certain cases,
vandalism. The foregoing list is merely indicative of certain kinds of uninsured
risks and is not intended to be all-inclusive. The Company may require Mortgaged
Properties in certain locations to be covered by policies of earthquake
insurance, to the extent it is reasonably available. When any improvement to a
Mortgaged Property is located in a designated flood area and in a community
which participates in the National Flood Insurance Program at the time of
origination of the related Mortgage Loan, and flood insurance is required and
available, the Pooling Agreement requires the Master Servicer, through the
Seller/Servicer responsible for servicing such Mortgage Loan, or the Servicer,
as applicable, to cause the Mortgagor to acquire and maintain such insurance.
 
    The hazard insurance policies covering the Mortgaged Properties typically
contain a clause which, in effect, requires the insured at all times to carry
insurance of a specified percentage (generally 80% to 90%) of the full
replacement value of the improvements on the property in order to recover the
full amount of any partial loss. If the insured's coverage falls below this
specified percentage, such clause provides that the insurer's liability in the
event of partial loss does not exceed the larger of (i) the replacement cost of
the improvements less physical depreciation, and (ii) such proportion of the
loss, without deduction for depreciation, as the amount of insurance carried
bears to the specified percentage of the full replacement cost of such
improvements.
 
    Neither the Seller/Servicer with respect to Series of Certificates as to
which the Company will act as Master Servicer, or the Servicer with respect to
Series of Certificates as to which the Company will not act as Master Servicer,
will require that a hazard or flood insurance policy be maintained for any
Cooperative Loan or Mortgage Loan secured by a condominium apartment. With
respect to a Cooperative Loan, generally the Cooperative itself is responsible
for maintenance of hazard insurance for the property owned by the Cooperative,
and the tenant-stockholders of the Cooperative do not maintain individual hazard
insurance policies. To the extent, however, that a Cooperative and the related
borrower on a Cooperative Note do not maintain such insurance or do not maintain
adequate coverage or any insurance proceeds are not applied to the restoration
of the damaged property, damage to such borrower's cooperative apartment or such
Cooperative's building could significantly reduce the value of the collateral
securing such Cooperative Note. With respect to a Mortgage Loan secured by a
condominium apartment, the condominium owner's association for the related
building generally is responsible for maintenance of hazard insurance for such
building, and the condominium owners do not maintain individual hazard insurance
policies. To the extent that the owner of a Mortgage Loan secured by a
condominium apartment and the related condominium owner's association do not
maintain such insurance or do not maintain adequate coverage or any insurance
proceeds are not applied to the restoration of the damaged property, damage to
such borrower's condominium apartment or the related building could
significantly reduce the value of the Mortgaged Property.
 
    Since the amount of hazard insurance the Master Servicer or the
Seller/Servicers, or the Servicer, as applicable, will cause to be maintained on
the Mortgaged Properties declines as the principal balances owing on the related
Mortgage Loans decrease, and since residential properties have historically
appreciated in value over time, in the event of partial loss, hazard insurance
proceeds may be insufficient to restore fully the damaged property. See
"Description of Credit Enhancements-- Special Hazard Insurance" for a
description of the limited protection afforded by the Special Hazard Insurance
Policy, Letter of Credit or Reserve Fund, if any is obtained, against losses
occasioned by certain hazards which are otherwise uninsured against, as well as
against losses caused by the application of the clause described in the
preceding paragraph.
 
    Any losses incurred with respect to Mortgage Loans due to uninsured risks
(including earthquakes, mudflows and floods) or insufficient hazard insurance
proceeds could affect distributions to the Certificateholders.
 
                                       43
<PAGE>
                       DESCRIPTION OF CREDIT ENHANCEMENTS
 
    To the extent provided in the applicable Prospectus Supplement, credit
enhancement for each Series of Certificates may be comprised of one or more of
the following components, each of which will have a dollar limit. Credit
enhancement components may include coverage with respect to losses that are (i)
attributable to the Mortgagor's failure to make any payment of principal or
interest as required under the Mortgage Note, but not including Special Hazard
Losses, Extraordinary Losses (as defined below) or other losses resulting from
damage to a Mortgaged Property, Bankruptcy Losses or Fraud Losses (any such
loss, a "Defaulted Mortgage Loss"); (ii) of a type generally covered by a
Special Hazard Insurance Policy (any such loss, a "Special Hazard Loss"); (iii)
attributable to certain actions which may be taken by a bankruptcy court in
connection with a Mortgage Loan, including a reduction by a bankruptcy court of
the principal balance of or the Mortgage Interest Rate on a Mortgage Loan or an
extension of its maturity (any such loss, a "Bankruptcy Loss"); (iv) incurred on
defaulted Mortgage Loans as to which there was fraudulent conduct or negligence
by either the Seller, the Seller/Servicer, the Servicer or the Mortgagor in
connection with such Mortgage Loans (any such loss, a "Fraud Loss"); and (v)
attributable to shortfalls in the payment of amounts due to one or more Classes
of Certificates. Losses occasioned by war, civil insurrection, certain
governmental actions, nuclear reaction, chemical contamination, errors in
design, faulty workmanship or materials or waste by the Mortgagor
("Extraordinary Losses") will not be covered. To the extent that the credit
enhancement for any Series of Certificates is exhausted, the Certificateholders
will bear all further risks of loss not otherwise insured against.
 
    As set forth below and in the applicable Prospectus Supplement, (i) coverage
with respect to Defaulted Mortgage Losses may be provided by one or more of a
Letter of Credit, Reserve Fund or a Mortgage Pool Insurance Policy, (ii)
coverage with respect to Special Hazard Losses may be provided by one or more of
a Letter of Credit, Reserve Fund or a Special Hazard Insurance Policy (any
instrument, to the extent providing such coverage, a "Special Hazard
Instrument"); (iii) coverage with respect to Bankruptcy Losses may be provided
by one or more of a Letter of Credit, Reserve Fund or Bankruptcy Bond (any
instrument, to the extent providing such coverage, a "Bankruptcy Instrument")
and (iv) coverage with respect to Fraud Losses may be provided by one or more of
a Letter of Credit, Reserve Fund or Fraud Bond (any instrument, to the extent
providing such coverage, a "Fraud Instrument"). In addition, if provided in the
applicable Prospectus Supplement, in lieu of or in addition to any or all of the
foregoing arrangements, credit enhancement may be in the form of subordination
of one or more Classes of Certificates to provide credit support to one or more
other Classes of Certificates.
 
    The amounts and types of credit enhancement arrangements as well as the
provider thereof, if applicable, with respect to each Series of Certificates
will be set forth in the related Prospectus Supplement. To the extent provided
in the applicable Prospectus Supplement and the Pooling Agreement, the credit
enhancement arrangements may be periodically modified, reduced and substituted
for based on the aggregate outstanding principal balance of the Mortgage Loans
covered thereby. If specified in the applicable Prospectus Supplement, credit
support for a Series of Certificates may cover one or more other series of
certificates issued by the Company or others.
 
    Unless otherwise specified in the applicable Prospectus Supplement, to the
extent permitted by any applicable rating agency and provided that the then
current ratings of the Certificates are maintained, coverage under any credit
enhancement may be cancelled or reduced.
 
    The descriptions of any credit enhancement instruments included in this
Prospectus or any Prospectus Supplement and the coverage thereunder do not
purport to be complete and are qualified in their entirety by reference to the
actual forms of governing documents, copies of which are available upon request.
 
MORTGAGE POOL INSURANCE
 
    A Mortgage Pool Insurance Policy may be obtained for a particular Series of
Certificates. Any such policy will be obtained by the Company or the Servicer,
as applicable, from a Qualified Insurer for the Mortgage Pool, covering loss by
reason of the default in payments on any Mortgage Loans included therein that
are not covered as to their entire outstanding principal balances by Primary
Insurance, FHA Insurance or VA Guarantees. Each Mortgage Pool Insurance Policy
will cover all or a portion of
 
                                       44
<PAGE>
those Mortgage Loans in a Mortgage Pool in an amount to be specified in the
applicable Prospectus Supplement or in the related Current Report on Form 8-K.
The term "Mortgage Pool Insurance Policy" wherever used in this Prospectus or
any Supplement shall refer to one or more such Mortgage Pool Insurance Policies
as the context may require. The identity of the insurer or insurers and certain
financial information with respect to the insurer or insurers for each Mortgage
Pool will be contained in the applicable Prospectus Supplement or in the related
Current Report on Form 8-K. The Trustee will be the named insured under any
Mortgage Pool Insurance Policy. A Mortgage Pool Insurance Policy is not a
blanket policy against loss, since claims thereunder may only be made respecting
particular defaulted Mortgage Loans and only upon the satisfaction of certain
conditions precedent described below.
 
    Any Mortgage Pool Insurance Policy will provide that no claim may be validly
presented thereunder unless (i) hazard insurance on the property securing the
defaulted Mortgage Loan has been kept in force and real estate taxes and other
protection and preservation expenses have been paid, (ii) if there has been
physical loss or damage to the Mortgaged Property, it has been restored to its
condition (reasonable wear and tear excepted) at the Cut-Off Date, (iii) any
required Primary Insurance Policy is in effect for the defaulted Mortgage Loan
and a claim thereunder has been submitted and settled, and (iv) the insured has
acquired good and merchantable title to the Mortgaged Property free and clear of
liens except permitted encumbrances. Assuming the satisfaction of these
conditions, the insurer will have the option to either (i) purchase the property
securing the defaulted Mortgage Loan at a price equal to the principal balance
thereof, plus accrued and unpaid interest at the Mortgage Interest Rate to the
date of purchase, less the amount of any loss paid under a Primary Insurance
Policy, if any, or (ii) pay the difference between the proceeds received from an
approved sale of the property and the principal balance of the defaulted
Mortgage Loan, plus accrued and unpaid interest at the Mortgage Interest Rate to
the date of payment of the claim, less the amount of such loss paid under a
Primary Insurance Policy, if any. In each case, the insurer will reimburse the
Master Servicer and the Seller/Servicer, or the Servicer with respect to Series
of Certificates for which the Company will not act as Master Servicer, for
certain expenses incurred by them.
 
    An endorsement (an "Advance Claims Endorsement") may be issued to any
Mortgage Pool Insurance Policy which provides that the Insurer will make
advances of monthly principal and interest payments on Mortgage Loans as to
which the Seller/Servicer, or the Servicer with respect to Series of
Certificates for which the Company will not act as Master Servicer, has not
received a payment from the related Mortgagor and neither the Seller/Servicer
nor the Master Servicer, or the Servicer, as applicable, has advanced such
payment. The presence of such endorsement, if any, will be disclosed in the
Prospectus Supplement.
 
    An endorsement may also be issued to any Mortgage Pool Insurance Policy
which provides that the insurer will pay claims presented under the Mortgage
Pool Insurance Policy although claims made against the applicable Primary
Insurance Policy have not been settled due to the insolvency, bankruptcy,
receivership or assignment for the benefit of creditors of the issuer of the
Primary Insurance Policy. The presence of such endorsement, if any, will be
disclosed in the Prospectus Supplement.
 
    Unless otherwise specified in the applicable Prospectus Supplement, to the
extent permitted by any applicable rating agency and provided that the then
current ratings of the Certificates are maintained, coverage under any Mortgage
Pool Insurance Policy may be cancelled or reduced.
 
    The original amount of coverage under any Mortgage Pool Insurance Policy
will be reduced over the life of the Certificates by the aggregate dollar amount
of claims paid, less certain amounts realized by the insurer upon disposition of
foreclosed properties. The amount of claims paid includes certain expenses
incurred by the Master Servicer, or the Servicer with respect to Series of
Certificates for which the Company will not act as Master Servicer, as well as
accrued interest on delinquent Mortgage Loans to the date of payment of the
claim. Accordingly, if aggregate net claims paid under any Mortgage Pool
Insurance Policy reach the original policy limit, coverage thereunder will lapse
and any further losses will be borne by Certificateholders. In addition, in such
event, the Master Servicer or the Servicer, as applicable, will not be obligated
(unless sufficient recoveries from other sources are expected) to make any
further Advances, since such Advances would no longer be ultimately recoverable
under the Mortgage Pool Insurance Policy. See "Description of
Certificates--Advances".
 
                                       45
<PAGE>
    Since the property subject to a defaulted Mortgage Loan must be restored to
its original condition prior to claiming against the insurer, no Mortgage Pool
Insurance Policy will provide coverage against hazard losses. As set forth under
"Primary Insurance, FHA Mortgage Insurance, VA Mortgage Guaranty, Hazard
Insurance; Claims Thereunder", the hazard insurance policies covering the
Mortgage Loans typically exclude from coverage physical damage resulting from a
number of causes, and even when the damage is covered, may afford recoveries
which are significantly less than the full replacement of such losses. Further,
any Special Hazard Insurance Policy which may be obtained does not cover all
risks, and such coverage will be limited in amount. See "--Special Hazard
Insurance" below. Certain hazard risks will, as a result, be uninsured against
and will therefore be borne by Certificateholders.
 
    A Mortgage Pool Insurance Policy may include a provision permitting the
insurer to purchase defaulted Mortgage Loans from the Trust.
 
    See "--The Fraud Bond" below for a discussion of the possible effect of
fraudulent conduct or negligence by the Seller, the Seller/Servicer, the
Servicer or the Mortgagor with respect to a Mortgage Loan on the coverage of a
Mortgage Pool Insurance Policy.
 
SUBORDINATION
 
    If so specified in the applicable Prospectus Supplement, distributions with
respect to scheduled principal, Principal Prepayments, interest or any
combination thereof that otherwise would have been payable to one or more
Classes of Certificates of a Series (the "Subordinated Certificates") will
instead be payable to holders of one or more other Classes of such Series (the
"Senior Certificates") under the circumstances and to the extent specified in
the Prospectus Supplement. If specified in the applicable Prospectus Supplement,
delays in receipt of scheduled payments on the Mortgage Loans and losses on
defaulted Mortgage Loans will be borne first by the various Classes of
Subordinated Certificates and thereafter by the various Classes of Senior
Certificates, in each case under the circumstances and subject to the
limitations specified in the Prospectus Supplement. The aggregate distributions
in respect of delinquent payments on the Mortgage Loans over the lives of the
Certificates or at any time, the aggregate losses in respect of defaulted
Mortgage Loans which must be borne by the Subordinated Certificates by virtue of
subordination and the amount of the distributions otherwise distributable to the
Subordinated Certificateholders that will be distributable to Senior
Certificateholders on any Distribution Date may be limited as specified in the
applicable Prospectus Supplement. If the aggregate distribution with respect to
delinquent payments on the Mortgage Loans or aggregate losses in respect of such
Mortgage Loans were to exceed the total amounts payable and available for
distribution to holders of Subordinated Certificates or, if applicable, were to
exceed the specified maximum amount, holders of Senior Certificates could
experience losses on the Certificates.
 
    In addition to or in lieu of the foregoing, if so specified in the
applicable Prospectus Supplement, all or any portion of distributions otherwise
payable to holders of Subordinated Certificates on any Distribution Date may
instead be deposited into one or more reserve accounts (the "Reserve Account")
established by the Trustee. If so specified in the applicable Prospectus
Supplement, such deposits may be made on each Distribution Date, on each
Distribution Date for specified periods or until the balance in the Reserve
Account has reached a specified amount and, following payments from the Reserve
Account to holders of Senior Certificates or otherwise, thereafter to the extent
necessary to restore the balance in the Reserve Account to required levels, in
each case as specified in the Prospectus Supplement. If so specified in the
applicable Prospectus Supplement, amounts on deposit in the Reserve Account may
be released to the Company, the Servicer or the Seller, as applicable, or the
holders of any Class of Certificates at the times and under the circumstances
specified in the Prospectus Supplement.
 
    If specified in the applicable Prospectus Supplement, various Classes of
Senior Certificates and Subordinated Certificates may themselves be subordinate
in their right to receive certain distributions to other Classes of Senior and
Subordinated Certificates, respectively, through a cross support mechanism or
otherwise.
 
                                       46
<PAGE>
    As between Classes of Senior Certificates and as between Classes of
Subordinated Certificates, distributions may be allocated among such classes (i)
in the order of their scheduled final distribution dates, (ii) in accordance
with a schedule or formula, (iii) in relation to the occurrence of events, or
(iv) otherwise, in each case as specified in the applicable Prospectus
Supplement. As between Classes of Subordinated Certificates, payments to holders
of Senior Certificates on account of delinquencies or losses and payments to any
Reserve Account will be allocated as specified in the Prospectus Supplement.
 
THE FRAUD BOND
 
    Some or all of the Primary Insurance Policies covering Mortgage Loans in any
Mortgage Pool may contain an exclusion from coverage for Fraud Losses. To
provide limited protection to Certificateholders against losses in the event
that coverage relating to a Mortgage Loan which otherwise would have been
available under a Primary Insurance Policy is not ultimately available by reason
of such an exclusion, if so specified in the applicable Prospectus Supplement, a
Fraud Instrument may be obtained or established by the Company or the Servicer,
as applicable, for the Mortgage Pool. The type, coverage amount and term of any
such Fraud Instrument will be disclosed in the applicable Prospectus Supplement
or in the related Current Report on Form 8-K, and the coverage amount may be
cancelled or reduced during the life of the Mortgage Pool, provided that the
then current ratings of the Certificates will not be adversely affected thereby.
The Company or the Servicer, as applicable, may also replace the initial Fraud
Instrument with any other type of Fraud Instrument, provided that the then
current ratings of the Certificates will not be adversely affected thereby. The
identity of the issuer of any Fraud Bond or the Letter of Credit providing such
coverage and certain financial information with respect to such issuer will be
contained in the applicable Prospectus Supplement or related Current Report on
Form 8-K.
 
    In addition, the Company understands that, regardless of whether exclusion
language such as that described above is included in the insurance documents, it
is the policy of some or all issuers of Primary Insurance Policies and of
Mortgage Pool Insurance Policies to deny coverage in circumstances involving
fraudulent conduct or negligence by either the Seller, the Seller/Servicer, the
Servicer or the Mortgagor. It is unclear whether any such denial would be upheld
by a court. Neither the repurchase obligation of the Company with respect to
Series of Certificates as to which the Company will act as Master Servicer, or
the Seller with respect to Series of Certificates as to which the Company will
not act as Master Servicer, nor any of the Fraud Instruments described above
would apply to any such denial of coverage unless, as described above, such
denial is based upon a specific exclusion relating to fraudulent conduct or
negligence which is included in a Primary Insurance Policy.
 
THE BANKRUPTCY BOND
 
    The Prospectus Supplement for certain Series may specify that the Master
Servicer with respect to Series of Certificates as to which the Company will act
as Master Servicer, or the Servicer with respect to Series of Certificates as to
which the Company will not act as Master Servicer, has undertaken to pay to the
Trustee for the benefit of Certificateholders any portion of the principal
balance of a Mortgage Loan which becomes unsecured pursuant to a proceeding
under Chapter 7, 11 or 13 of the Federal Bankruptcy Code. If such obligation is
undertaken, the Master Servicer or the Servicer, as applicable, will also agree
to pay to the Trustee for the benefit of Certificateholders any shortfall in
payment of principal and interest resulting from the recasting of any originally
scheduled monthly principal and interest payment pursuant to a ruling under the
Bankruptcy Code. These payment obligations will be subject to the limitations
specified in the applicable Pooling Agreement. The Master Servicer or the
Servicer, as applicable, will have the option, in lieu of making such payments,
to repurchase any Mortgage Loan affected by bankruptcy court rulings. To insure
the Master Servicer's or the Servicer's obligation to make the payments
described above, the Master Servicer or the Servicer, as applicable, will obtain
or establish a Bankruptcy Instrument in an initial amount specified in the
Prospectus Supplement or in the related Current Report on Form 8-K. The
Prospectus Supplement or Current Report on Form 8-K may also specify that,
provided that the then current ratings of the Certificates are maintained,
coverage under any Bankruptcy Instrument may be cancelled or reduced. The Master
Servicer with respect to Series of Certificates as to which the Company will act
as Master Servicer, or the Servicer with respect to Series of Certificates as to
which
 
                                       47
<PAGE>
the Company will not act as Master Servicer, may also replace the initial method
pursuant to which such coverage is provided with either of the other two
alternative methods, provided that the then current ratings of the Certificates
will not be adversely affected thereby.
 
SPECIAL HAZARD INSURANCE
 
    A Special Hazard Insurance Instrument may be established or obtained by the
Company or the Servicer, as applicable, for certain Series. Any Special Hazard
Insurance Instrument will, subject to limitations described below, protect the
holders of the Certificates evidencing such Mortgage Pool from (i) loss by
reason of damage to properties subject to defaulted Mortgage Loans covered
thereby caused by certain hazards (including earthquakes in some geographic
areas, mud flows and floods) not insured against under customary standard forms
of fire and hazard insurance policies with extended coverage, and (ii) loss on
such loans caused by reason of the application of the co-insurance clause
typically contained in hazard insurance policies. The Master Servicer with
respect to Series of Certificates as to which the Company will act as Master
Servicer, or the Servicer with respect to Series of Certificates as to which the
Company will not act as Master Servicer, may also replace the initial method
pursuant to which such coverage is provided with either of the other two
alternative methods, provided that the then current ratings of the Certificates
will not be adversely affected thereby. The Prospectus Supplement or Current
Report on Form 8-K may also specify that, provided the then current ratings of
the Certificates are maintained, coverage under any Special Hazard Instrument
may be cancelled or reduced. Any Special Hazard Insurance Policy will be issued
by an insurance company licensed to transact a property and casualty insurance
business in each state in which Mortgaged Properties covered thereby are
located. The identity of the issuer of any Special Hazard Insurance Policy or
the Letter of Credit providing such coverage and certain financial information
with respect to such issuer will be contained in the related Prospectus
Supplement. No Special Hazard Insurance Instrument will cover Extraordinary
Losses.
 
    Subject to the foregoing limitations, the terms of any Special Hazard
Insurance Instrument will provide generally that, where there has been damage to
property securing a defaulted Mortgage Loan covered by such instrument and such
damage is not fully covered by the hazard insurance policy maintained with
respect to such property, the Special Hazard Insurance Instrument will pay
either (i) the cost of repair of such property or (ii) the unpaid principal
balance of such Mortgage Loan at the time of an approved sale of such property,
plus accrued interest at the Mortgage Interest Rate to the date of claim
settlement and certain expenses incurred in respect of such property, less any
net proceeds upon the sale of such property. In either case, the amount paid
under any Special Hazard Insurance Instrument will be reduced by the proceeds,
if any, received under the hazard insurance policy maintained with respect to
such property. It is expected that the Mortgage Pool Insurer, if any, will
represent to the Master Servicer or the Servicer, as applicable, that
restoration of the property securing a Mortgage Loan from the proceeds described
under (i) above will satisfy the condition under any related Mortgage Pool
Insurance Policy that the property securing a defaulted Mortgage Loan be
restored before a claim under any such policy may be validly presented in
respect of such Mortgage Loan. The payment described under (ii) above will
render unnecessary presentation of a claim in respect of such Mortgage Loan
under any Mortgage Pool Insurance Policy. Therefore, so long as any Mortgage
Pool Insurance Policy for a Series of Certificates remains in effect, the
decision to pay the cost of repair rather than to pay the unpaid principal
balance of the related Mortgage Loan, plus accrued interest and certain
expenses, will not affect the amount of the total insurance proceeds paid to the
holders of the Certificates of that Series with respect to such Mortgage Loan,
but will affect the amount of special hazard insurance coverage remaining under
any Special Hazard Insurance Instrument and the coverage remaining under any
Mortgage Pool Insurance Policy obtained for that Series.
 
LETTER OF CREDIT
 
    If any component of credit enhancement as to any Series of Certificates is
to be provided by a letter of credit (the "Letter of Credit"), a bank or other
entity (the "Letter of Credit Bank") will deliver to the Trustee an irrevocable
Letter of Credit. The Letter of Credit Bank and certain information with respect
thereto, as well as the amount available under the Letter of Credit with
 
                                       48
<PAGE>
respect to each component of credit enhancement, will be specified in the
applicable Prospectus Supplement. The Letter of Credit will expire on the
expiration date set forth in the related Prospectus Supplement, unless earlier
terminated or extended in accordance with its terms.
 
    The Letter of Credit may also provide for the payment of Advances which the
Master Servicer with respect to Series of Certificates as to which the Company
will act as Master Servicer, or the Servicer with respect to Series of
Certificates as to which the Company will not act as Master Servicer, would be
obligated to make with respect to delinquent monthly payments.
 
RESERVE FUND
 
    If so specified in the related Prospectus Supplement, the Company, the
Servicer or the Seller, as applicable, will deposit or cause to be deposited in
a Reserve Fund cash or Eligible Investments in specified amounts, or any other
instruments satisfactory to the rating agency or agencies rating the
Certificates offered pursuant to such Prospectus Supplement, which will be
applied and maintained in the manner and under the conditions specified in such
Prospectus Supplement. In the alternative or in addition to such deposit, to the
extent described in the related Prospectus Supplement, a Reserve Fund may be
funded through application of all or a portion of amounts otherwise payable on
one or more related Classes of Certificates, from Retained Yield, or otherwise.
Amounts in a Reserve Fund may be used to provide one or more components of
credit enhancement, or applied to reimburse the Master Servicer with respect to
Series of Certificates as to which the Company will act as Master Servicer, or
the Servicer with respect to Series of Certificates as to which the Company will
not act as Master Servicer, for outstanding Advances, or may be used for other
purposes, in the manner and to the extent specified in the related Prospectus
Supplement. Unless otherwise provided in the related Prospectus Supplement, any
such Reserve Fund will not be deemed to be part of the related Trust Fund.
 
    Amounts deposited in any Reserve Fund for a Series of Certificates will be
invested in Eligible Investments by, or at the direction of, and for the benefit
of the Master Servicer or the Certificate Administrator, as applicable, or any
other person named in the related Prospectus Supplement. Unless otherwise
specified in the applicable Prospectus Supplement, any amounts remaining in the
Reserve Fund upon the termination of the Trust Fund will be returned to whomever
deposited such amounts in the Reserve Fund.
 
CERTIFICATE INSURANCE POLICIES
 
    If so specified in the related Prospectus Supplement, the Company or the
Servicer may obtain one or more certificate insurance policies, issued by
insurers acceptable to the rating agency or agencies rating the Certificates
offered pursuant to such Prospectus Supplement, insuring the holders of one or
more Classes of Certificates the payment of amounts due in accordance with the
terms of such Class or Classes of Certificates, subject to such limitations and
exceptions as are set forth in the applicable Prospectus Supplement.
 
MAINTENANCE OF CREDIT ENHANCEMENTS; CLAIMS THEREUNDER
    AND OTHER REALIZATION UPON DEFAULTED MORTGAGE LOANS
 
    For each Series of Certificates which will be covered by a Mortgage Pool
Insurance Policy, or a Letter of Credit established in lieu of such policy (such
coverage to be disclosed in the applicable Prospectus Supplement), the Master
Servicer with respect to Series of Certificates as to which the Company will act
as Master Servicer, or the Servicer with respect to Series of Certificates as to
which the Company will not act as Master Servicer, will exercise its best
reasonable efforts to keep such Mortgage Pool Insurance Policy or Letter of
Credit in full force and effect throughout the term of the Pooling Agreement,
unless coverage thereunder has been exhausted through the payment of claims or
until such instrument is replaced in accordance with the terms of the Pooling
Agreement. Unless otherwise specified in the applicable Prospectus Supplement,
the Master Servicer or the Servicer, as applicable, will agree to pay the
premiums for any Mortgage Pool Insurance Policy, and the fee for any Letter of
Credit, on a timely basis. In the event that the insurer under the Mortgage Pool
Insurance Policy ceases to be a Qualified Insurer (as defined in the Pooling
Agreement), or the Letter of Credit Bank ceases to be acceptable to the agency
or agencies, if any, rating the Series, the Master Servicer or the Servicer, as
applicable, will use its best reasonable efforts to obtain from another
Qualified Insurer
 
                                       49
<PAGE>
or letter of credit issuer a replacement policy or letter of credit comparable
to the Mortgage Pool Insurance Policy or Letter of Credit which it replaces,
with total coverage equal to the then outstanding coverage of the Mortgage Pool
Insurance Policy or Letter of Credit, provided that if the cost of the
replacement policy or letter of credit is greater than the cost of the Mortgage
Pool Insurance Policy or Letter of Credit being replaced, the coverage of the
replacement policy or letter of credit for a Series of Certificates may be
reduced to a level such that its premium rate or cost does not exceed 150% of
the premium rate or cost of the Mortgage Pool Insurance Policy or Letter of
Credit for a Series which is rated by one or more rating agencies, or 100% of
the premium rate or cost for such policy or letter of credit for a Series which
is not so rated.
 
    In addition, the Master Servicer or the Servicer, as applicable, may
substitute at any time a Mortgage Pool Insurance Policy or Letter of Credit for
an existing Mortgage Pool Insurance Policy or Letter of Credit. In no event,
however, may the Master Servicer or the Servicer, as applicable, provide a
Letter of Credit in lieu of a Mortgage Pool Insurance Policy, or vice-versa, or
substitute one such instrument for another, except under the circumstances
detailed in the preceding paragraph, if such action will impair the then current
ratings, if any, of the Certificates.
 
    Unless otherwise specified in the applicable Prospectus Supplement, each
Seller/Servicer with respect to Series of Certificates as to which the Company
will act as Master Servicer, or the Servicer with respect to Series of
Certificates as to which the Company will not act as Master Servicer, will cause
a Primary Insurance Policy to be maintained in full force and effect with
respect to each Mortgage Loan it services with a loan-to-value ratio in excess
of 80%; provided, however, that if the loan-to-value ratio of a Mortgage Loan
based on a subsequent appraisal of the Mortgaged Property is less than 80%, such
Primary Insurance Policy may be terminated, if so specified in the applicable
Prospectus Supplement. Each Seller/Servicer or the Servicer, as applicable, will
agree to pay the premium for each Primary Insurance Policy on a timely basis in
the event that the Mortgagor does not make such payments. See "Primary
Insurance, FHA Mortgage Insurance, VA Mortgage Guaranty, Hazard Insurance;
Claims Thereunder--Primary Insurance" herein.
 
    For each Series of Certificates which will be covered by a Special Hazard
Insurance Instrument (such coverage to be disclosed in the applicable Prospectus
Supplement), the Master Servicer with respect to Series of Certificates as to
which the Company will act as Master Servicer, or the Servicer with respect to
Series of Certificates as to which the Company will not act as Master Servicer,
will exercise its best reasonable efforts to keep such Special Hazard Insurance
Instrument in full force and effect throughout the term of the Pooling
Agreement, unless coverage thereunder has been exhausted through the payment of
claims or until such Special Hazard Insurance Instrument has been replaced in
accordance with the terms of the Pooling Agreement. So long as any applicable
rating on a Series of Certificates will be maintained, the Master Servicer or
the Servicer, as applicable, may at any time replace the initial instrument
providing special hazard coverage with either of the other two alternative
methods. Unless otherwise specified in the applicable Prospectus Supplement, the
Master Servicer or the Servicer, as applicable, will agree to pay the premium
for any Special Hazard Insurance Policy (or Letter of Credit obtained in lieu
thereof) on a timely basis. Unless otherwise specified in the applicable
Prospectus Supplement, any such policy will provide for a fixed premium rate on
the declining balance of the Mortgage Loans. In the event that any Special
Hazard Insurance Policy is cancelled or terminated for any reason other than the
exhaustion of total policy coverage, the Master Servicer or the Servicer, as
applicable, is obligated either to substitute a Letter of Credit or Reserve Fund
or to exercise its best reasonable efforts to obtain from another insurer a
replacement policy comparable to such Special Hazard Insurance Policy with a
total coverage which is equal to the then existing coverage of such Special
Hazard Insurance Policy; provided, however, that if the cost of any such
replacement policy shall be greater than the cost of the original Special Hazard
Insurance Policy, the amount of coverage of such replacement policy may be
reduced to a level such that the cost shall be equal to the cost of the original
Special Hazard Insurance Policy. As indicated above, in lieu of obtaining a
replacement Special Hazard Insurance Policy, the Master Servicer or the
Servicer, as applicable, may obtain a Letter of Credit or establish a Reserve
Fund in accordance with terms prescribed by any applicable rating agency so that
any rating obtained for the Certificates will not be impaired.
 
                                       50
<PAGE>
    For each Series of Certificates which will be covered by a Fraud Instrument
(such coverage to be disclosed in the applicable Prospectus Supplement), the
Master Servicer with respect to Series of Certificates as to which the Company
will act as Master Servicer, or the Servicer with respect to Series of
Certificates as to which the Company will not act as Master Servicer, will
exercise its best reasonable efforts to maintain and keep any such Fraud
Instrument in full force and effect throughout the required term as set forth in
the applicable Prospectus Supplement, unless coverage thereunder has been
exhausted through the payment of claims. The Master Servicer or the Servicer, as
applicable, will agree to pay the premium for any Fraud Bond or Bankruptcy Bond
on a timely basis.
 
    For each Series of Certificates or Class of Certificates which will be
covered by a certificate insurance policy or a Letter of Credit or Reserve Fund
(such coverage to be disclosed in the applicable Prospectus Supplement), the
Master Servicer with respect to Series of Certificates as to which the Company
will act as Master Servicer, or the Servicer with respect to Series of
Certificates as to which the Company will not act as Master Servicer, will
exercise its best reasonable efforts to maintain and keep any such certificate
insurance policy, Letter of Credit or Reserve Fund in full force and effect
throughout the required term set forth in the applicable Prospectus Supplement.
Unless otherwise specified in the Prospectus Supplement, the Master Servicer or
the Servicer, as applicable, will agree to pay the premium for any certificate
insurance policy on a timely basis.
 
    The Master Servicer or the Seller/Servicers, with respect to Series of
Certificates as to which the Company will act as Master Servicer, or the
Servicer with respect to Series of Certificates as to which the Company will not
act as Master Servicer, on behalf of the Trustee and Certificateholders, will
present claims to the issuer of any applicable Primary Insurance Policy, FHA
Insurance Policy, VA Guaranty, Mortgage Pool Insurance Policy, Special Hazard
Insurance Policy or Letter of Credit, or under any Reserve Fund or other form of
credit enhancement, and will take such reasonable steps as are necessary to
permit recovery under such insurance policies or alternative coverages
respecting defaulted Mortgage Loans. With respect to any applicable Fraud Bond,
Bankruptcy Bond or certificate insurance policy, the Trustee will present claims
to the issuer of such bond or policy on behalf of the Certificateholders. As set
forth above, all collections by the Master Servicer or the Seller/Servicer, or
the Servicer, as applicable, under such policies or alternative coverages that
are not applied to the restoration of the related Mortgaged Property are to be
deposited in the applicable Custodial Account for P&I, the Investment Account or
the Certificate Account, subject to withdrawal as heretofore described.
 
    If any property securing a defaulted Mortgage Loan is damaged and proceeds,
if any, from the related hazard insurance policy or any applicable Special
Hazard Insurance Policy (or Letter of Credit or Reserve Fund), as the case may
be, are insufficient to restore the damaged property to a condition sufficient
to permit recovery under any applicable Mortgage Pool Insurance Policy or
Primary Insurance Policy, the Master Servicer, with respect to Series of
Certificates as to which the Company will act as Master Servsicer, or the
Servicer with respect to Series of Certificates as to which the Company will not
act as Master Servicer, will not be required to expend its own funds to restore
the damaged property unless it determines (i) that such restoration will
increase the proceeds to Certificateholders upon liquidation of the Mortgage
Loan after reimbursement of the Master Servicer or the Servicer, as applicable,
for its expenses and (ii) that such expenses will be recoverable to it through
Liquidation Proceeds or Insurance Proceeds.
 
    If recovery under any Mortgage Pool Insurance Policy (or Letter of Credit
established in lieu of such policy), Primary Insurance Policy, FHA Insurance
Policy or VA Guaranty is not available because the Master Servicer, with respect
to Series of Certificates as to which the Company will act as Master Servicer,
or the Servicer with respect to Series of Certificates as to which the Company
will not act as Master Servicer, has been unable to make the determinations
described in the second preceding paragraph, or otherwise, the Seller/Servicer
or the Servicer, as applicable, is, nevertheless, obligated to follow such
normal practices and procedures as it deems necessary or advisable to realize
upon the defaulted Mortgage Loan. If the proceeds of any liquidation of the
property securing the defaulted Mortgage Loan are less than the principal
balance of the defaulted Mortgage Loan plus accrued and unpaid interest thereon
at the applicable Pass-Through Rate (after deduction of the Retained Yield, if
any, or a pro rata portion thereof as required by the applicable Pooling
Agreement), Certificateholders in the aggregate will realize a loss in the
amount of such difference plus the aggregate of expenses
 
                                       51
<PAGE>
incurred by the Master Servicer and the Seller/Servicer, or the Servicer, as
applicable, in connection with such proceedings and which are reimbursable under
the Pooling Agreement. In addition, and as set forth above, in the event that
the Master Servicer or the Servicer, as applicable, has expended its own funds
to restore damaged property and such funds have not been reimbursed under any
Special Hazard Insurance Policy or Letter of Credit or Reserve Fund, it will be
entitled to receive from the Certificate Account, out of related Liquidation
Proceeds or Insurance Proceeds, an amount equal to such expenses incurred by it,
in which event the Certificateholders may realize a loss up to the amount so
charged. Since Insurance Proceeds cannot exceed deficiency claims and certain
expenses incurred by the Master Servicer and the Seller/Servicers, or the
Servicer, as applicable, no insurance payments will result in a recovery to
Certificateholders which exceeds the principal balance of the defaulted Mortgage
Loan together with accrued and unpaid interest thereon at the applicable
Pass-Through Rate. In addition, where property securing a defaulted Mortgage
Loan can be resold for an amount exceeding the principal balance of any related
Mortgage Note together with accrued interest and expenses, it may be expected
that, where retention of any such amount is legally permissible, the insurer
will exercise its right under any related Mortgage Pool Insurance Policy to
purchase such property and realize for itself any excess proceeds. In addition,
with respect to certain Series of Certificates, if so provided in the applicable
Prospectus Supplement, the Master Servicer or the Servicer, as applicable, may
have the option to purchase from the Trust Fund any defaulted Mortgage Loan
after a specified period of delinquency. If a defaulted Mortgage Loan is not so
removed from the Trust Fund, then, upon the final liquidation thereof, if a loss
is realized which is not covered by any applicable form of credit enhancement or
other insurance, the Certificateholders will bear such loss. However, if a gain
results from the final liquidation of a defaulted Mortgage Loan which is not
required by law to be remitted to the related Mortgagor, the Master Servicer or
the Servicer, as applicable, will be entitled to retain such gain as additional
servicing compensation unless the applicable Prospectus Supplement provides
otherwise. See "Description of Credit Enhancements".
 
                  CERTAIN LEGAL ASPECTS OF THE MORTGAGE LOANS
 
    The Mortgages (other than the security agreements with respect to the
Cooperative Loans) will be either deeds of trust or mortgages, depending upon
the prevailing practice in the state in which the Mortgaged Property is located.
A mortgage creates a lien upon the real property encumbered by the mortgage. It
is not prior to the lien for real estate taxes and assessments. Priority between
mortgages depends on their terms and generally on the order of filing with a
state or county office. There are two parties to a mortgage: the mortgagor, who
is usually the borrower and homeowner, and the mortgagee, who is the lender.
Under the mortgage instrument, the mortgagor delivers to the mortgagee a note or
bond and the mortgage. Although a deed of trust is similar to a mortgage, a deed
of trust formally has three parties; the borrower-homeowner, called the trustor
(similar to a mortgagor), a lender, called the beneficiary (similar to a
mortgagee), and a third-party grantee, called the trustee. Under a deed of
trust, the trustor grants the property, irrevocably until the debt is paid, in
trust, generally with a power of sale, to the trustee to secure payment of the
obligation. In some cases, a mortgage will also contain a power of sale. The
trustee's authority under a deed of trust and the mortgagee's authority under a
mortgage are governed by law, by the express provisions of the deed of trust or
mortgage and, in some cases, by the directions of the beneficiary. For purposes
of the following discussion, "mortgagor" shall, as appropriate, refer to a
mortgagor or trustor and "lender" shall refer to a mortgagee or beneficiary. A
Mortgage Pool may also contain Cooperative Loans which are described below under
"--Cooperative Loans".
 
COOPERATIVE LOANS
 
    If specified in the Prospectus Supplement relating to a Series of
Certificates, the Mortgage Loans may also include Cooperative Loans. Each
promissory note (a "Cooperative Note") evidencing a Cooperative Loan will be
secured by a security interest in shares issued by the related private
cooperative housing corporation (a "Cooperative") that owns the related
apartment building, which is a corporation entitled to be treated as a housing
cooperative under federal tax law, and in the related proprietary lease or
occupancy agreement granting exclusive rights to occupy a specific dwelling unit
in the Cooperative's building. The security agreement will create a lien upon or
grant a security interest in the cooperative shares and proprietary lease or
occupancy agreement, the priority of which will depend on the terms of the
particular security agreement as well as the order of recordation of the
 
                                       52
<PAGE>
agreement (or the filing of the financing statements related thereto) in the
appropriate recording office or the taking of possession of the cooperative
shares, depending on the law of the state in which the cooperative is located.
Such a lien or security interest is not, in general, prior to liens in favor of
the Cooperative for unpaid assessments or common charges.
 
    Unless otherwise specified in the related Prospectus Supplement, all
cooperative buildings relating to the Cooperative Loans are located in the
States of New York and New Jersey. Generally, each Cooperative owns in fee or
has a leasehold interest in all the real property and owns in fee or leases the
building and all separate dwelling units therein. The Cooperative is directly
responsible for property management and, in most cases, payment of real estate
taxes, other governmental impositions and hazard and liability insurance. If
there is an underlying mortgage (or mortgages) on the Cooperative's building or
underlying land, as is generally the case, or an underlying lease of the land,
as is the case in some instances, the Cooperative, as mortgagor or lessee, as
the case may be, is also responsible for fulfilling such mortgage or rental
obligations. An underlying mortgage loan is ordinarily obtained by the
Cooperative in connection with either the construction or purchase of the
Cooperative's building or the obtaining of capital by the Cooperative. The
interest of the occupant under proprietary leases or occupancy agreements as to
which that Cooperative is the landlord are generally subordinate to the interest
of the holder of an underlying mortgage and to the interest of the holder of a
land lease. If the Cooperative is unable to meet the payment obligations (i)
arising under an underlying mortgage, the mortgagee holding an underlying
mortgage could foreclose on that mortgage and terminate all subordinate
proprietary leases and occupancy agreements or (ii) arising under its land
lease, the holder of the landlord's interest under the land lease could
terminate it and all subordinate proprietary leases and occupancy agreements. In
addition, an underlying mortgage on a Cooperative may provide financing in the
form of a mortgage that does not fully amortize, with a significant portion of
principal being due in one final payment at maturity. The inability of the
Cooperative to refinance a mortgage and its consequent inability to make such
final payment could lead to foreclosure by the mortgagee. Similarly, a land
lease has an expiration date and the inability of the Cooperative to extend its
term or, in the alternative, to purchase the land, could lead to termination of
the Cooperative's interest in the property and termination of all proprietary
leases and occupancy agreements. In either event, a foreclosure by the holder of
an underlying mortgage or the termination of the underlying lease could
eliminate or significantly diminish the value of any collateral held by the
lender who financed the purchase by an individual tenant-stockholder of shares
of the Cooperative or, in the case of a Mortgage Pool, the collateral securing
any related Cooperative Loans.
 
    Each Cooperative is owned by shareholders (referred to as
tenant-stockholders) who, through ownership of stock or shares in the
Cooperative, receive proprietary leases or occupancy agreements which confer
exclusive rights to occupy specific dwellings. Generally, a tenant-stockholder
of a Cooperative must make a monthly maintenance payment to the Cooperative
pursuant to the proprietary lease, which maintenance payment represents such
tenant-stockholder's PRO RATA share of the Cooperative's payments for its
underlying mortgage, real property taxes, maintenance expenses and other capital
or ordinary expenses. An ownership interest in a Cooperative and accompanying
occupancy rights may be financed through a Cooperative Loan evidenced by a
Cooperative Note and secured by an assignment of and a security interest in the
occupancy agreement or proprietary lease and a security interest in the shares
of the related Cooperative. The lender generally takes possession of the share
certificate and a counterpart of the proprietary lease or occupancy agreement
and a financing statement covering the proprietary lease or occupancy agreement
and the Cooperative shares is filed in the appropriate state and local offices
to perfect the lender's interest in its collateral. Subject to the limitations
discussed below, upon default of the tenant-stockholder, the lender may sue for
judgment on the Cooperative Note, dispose of the collateral at a public or
private sale or otherwise proceed against the collateral or tenant-stockholder
as an individual as provided in the security agreement covering the assignment
of the proprietary lease or occupancy agreement and the pledge of Cooperative
shares. See "-- Foreclosure on Shares of Cooperatives" below.
 
TAX ASPECTS OF COOPERATIVE OWNERSHIP
 
    In general, a "tenant-stockholder" (as defined in Section 216(b)(2) of the
Code) of a corporation that qualifies as a "cooperative housing corporation"
within the meaning of Section 216(b)(1) of the
 
                                       53
<PAGE>
Code is allowed a deduction under Section 216(a) of the Code for amounts paid or
accrued within his or her taxable year to the corporation representing his or
her proportionate share of certain interest expenses and certain real estate
taxes allowable as deductions to the corporation under Sections 163 and 164 of
the Code. In order for a corporation to qualify under Section 216(b)(1) of the
Code for the taxable year to which such interest and tax deductions relate, such
section requires, among other things, that at least 80% of the gross income of
the corporation be derived from its tenant-stockholders. By virtue of this
requirement, the status of a corporation for purposes of Section 216(b)(1) of
the Code must be determined on a year-to-year basis. Consequently, there can be
no assurance that Cooperatives relating to the Cooperative Loans will qualify
under such section for any particular year. In the event that such a Cooperative
fails to qualify for one or more years, the value of the collateral securing any
related Cooperative Loans could be significantly impaired because no deduction
would be allowable to tenant-stockholders under Section 216(a) of the Code with
respect to those years. In view of the significance of the tax benefits accorded
tenant-stockholders of a corporation that qualifies under Section 216(b)(1) of
the Code, the likelihood that such a failure would be permitted to continue over
a period of years appears remote.
 
FORECLOSURE
 
    Foreclosure may be accomplished by judicial action. The action is initiated
by the service of legal pleadings upon all parties having an interest in the
real property. Delays in completion of the foreclosure may occasionally result
from difficulties in locating necessary parties defendant. Judicial foreclosure
proceedings are generally not contested by any of the parties defendant.
However, when the lender's right to foreclose is contested, the legal
proceedings necessary to resolve the issue can be time consuming. After the
completion of judicial foreclosure, the court would issue a judgment of
foreclosure and would generally appoint a referee or other court officer to
conduct the sale of property.
 
    In many states, foreclosure of a mortgage or deed of trust may also be
accomplished by a nonjudicial sale under a specific provision in the mortgage or
deed of trust which authorizes the sale of the property at public auction upon
default by the mortgagor. The laws of the various states establish certain
notice requirements for non-judicial foreclosure sales. In some states, notice
of default must be recorded and sent to the mortgagor and to any person who has
recorded a request for a copy of a notice of default and notice of sale. In
addition, notice must be provided in some states to certain other persons
including junior lienholders and any other individual having an interest in the
real property. In some states, the mortgagor, or any other person having a
junior encumbrance on the real estate, may, during a reinstatement period, cure
the default by paying the entire amount in arrears, plus the costs and expenses
incurred in enforcing the obligation. Generally, state law controls the amount
of foreclosure expenses and costs, including limited attorneys' fees, which may
be recovered by a lender. Some states also require a notice of sale to be posted
in a public place and published for a specified period of time in one or more
newspapers. In addition, some state laws require that a copy of the notice of
sale be posted on the property and sent to all parties having an interest in the
real property.
 
    In case of foreclosure under either a mortgage or a deed of trust, the sale
by the receiver or other designated officer or by the trustee is a public sale.
However, because of a number of factors, including the difficulty a potential
buyer at the sale would have in determining the exact status of title and the
fact that the physical condition of the property may have deteriorated during
the foreclosure proceedings, it is uncommon for a third party to purchase the
property at the foreclosure sale. Rather, it is common for the lender to
purchase the property from the trustee or referee with a credit bid in an amount
equal to the principal amount of the mortgage or deed of trust, accrued and
unpaid interest and the expenses of foreclosure. Thereafter, the lender will
assume the burdens of ownership, including obtaining casualty insurance and
making such repairs at its own expense as are necessary to render the property
suitable for sale. The lender will commonly obtain the services of a real estate
broker and pay the broker's commission in connection with the sale of the
property. Depending upon market conditions, the ultimate proceeds of the sale of
the property may not equal the lender's investment in the property.
 
    Courts have imposed general equitable principles upon foreclosure
proceedings. These equitable principles are generally designed to relieve the
mortgagor from the legal effect of his defaults under the loan documents.
Examples of judicial remedies that have been fashioned include judicial
requirements that the lender undertake affirmative and sometimes expensive
actions to determine
 
                                       54
<PAGE>
the causes for the mortgagor's default and the likelihood that the mortgagor
will be able to reinstate the loan. In some cases, courts have substituted their
judgment for the lender's judgment and have required that lenders reinstate
loans or recast payment schedules in order to accommodate mortgagors who are
suffering from a temporary financial disability. In other cases, courts have
limited the right of the lender to foreclose if the default under the security
instrument is not monetary, such as the mortgagor failing to adequately maintain
or insure the property or the mortgagor executing a second mortgage or deed of
trust affecting the property. Some courts have been faced with the issue of
whether or not federal or state constitutional provisions reflecting due process
concerns for adequate notice require that mortgagors receive notices in addition
to the statutorily prescribed minimum. For the most part, these cases have
upheld the notice provisions as being reasonable or have found that the
foreclosure sale does not involve sufficient state action to afford
constitutional protections to the mortgagor.
 
FORECLOSURE ON SHARES OF COOPERATIVES
 
    The Cooperative shares owned by the tenant-stockholder, together with the
rights of the tenant-stockholder under the proprietary lease or occupancy
agreement, are pledged to the lender and are, in almost all cases, subject to
restrictions on transfer as set forth in the Cooperative's certificate of
incorporation and by-laws, as well as in the proprietary lease or occupancy
agreement. The proprietary lease or occupancy agreement, even while pledged, may
be cancelled by the Cooperative for failure by the tenant-stockholder to pay
maintenance or other obligations or charges owed by such tenant-stockholder,
including mechanics' liens against the Cooperative's building incurred by such
tenant-stockholder. Generally, maintenance and other obligations and charges
arising under a proprietary lease or occupancy agreement which are owed to the
Cooperative are made liens upon the shares to which the proprietary lease or
occupancy agreement relates. In addition, the proprietary lease or occupancy
agreement generally permits the Cooperative to terminate such lease or agreement
in the event the borrower defaults in the performance of covenants thereunder.
Typically, the lender and the Cooperative enter into a recognition agreement
which, together with any lender protection provisions contained in the
proprietary lease, establishes the rights and obligations of both parties in the
event of a default by the tenant-stockholder on its obligations under the
proprietary lease or occupancy agreement. A default by the tenant-stockholder
under the proprietary lease or occupancy agreement will usually constitute a
default under the security agreement between the lender and the
tenant-stockholder.
 
    The recognition agreement generally provides that, in the event that the
tenant-stockholder has defaulted under the proprietary lease or occupancy
agreement, the Cooperative will take no action to terminate such lease or
agreement until the lender has been provided with notice of and an opportunity
to cure the default. The recognition agreement typically provides that if the
proprietary lease or occupancy agreement is terminated, the Cooperative will
recognize the lender's lien against proceeds from a sale of the shares and the
proprietary lease or occupancy agreement allocated to the dwelling, subject,
however, to the Cooperative's right to sums due under such proprietary lease or
occupancy agreement or which have become liens on the shares relating to the
proprietary lease or occupancy agreement. The total amount owed to the
Cooperative by the tenant-stockholder, which the lender generally cannot
restrict and does not monitor, could reduce the amount realized upon a sale of
the collateral below the outstanding principal balance of the Cooperative Loan
and accrued and unpaid interest thereon.
 
    Recognition agreements also generally provide that in the event the lender
succeeds to the tenant-stockholder's shares and proprietary lease or occupancy
agreement as the result of realizing upon its collateral for a Cooperative Loan,
the lender must obtain the approval or consent of the board of directors of the
Cooperative as required by the proprietary lease before transferring the
Cooperative shares and assigning the proprietary lease. Such approval or consent
is usually based on the prospective purchaser's income and net worth, among
other factors, and may significantly reduce the number of potential purchasers,
which could limit the ability of the lender to sell and realize upon the value
of the collateral. Generally, the lender is not limited in any rights it may
have to dispossess the tenant-stockholder.
 
                                       55
<PAGE>
    Because of the nature of Cooperative Loans, lenders do not require the
tenant-stockholder (i.e., the borrower) to obtain title insurance of any type.
Consequently, the existence of any prior liens or other imperfections of title
affecting the Cooperative's building or real estate also may adversely affect
the marketability of the shares allocated to the dwelling unit in the event of
foreclosure.
 
    A foreclosure on the Cooperative shares is accomplished by public sale in
accordance with the provisions of Article 9 of the Uniform Commercial Code (the
"UCC") and the security agreement relating to those shares. Article 9 of the UCC
requires that a sale be conducted in a "commercially reasonable" manner. Whether
a sale has been conducted in a "commercially reasonable" manner will depend on
the facts in each case. In determining commercial reasonableness, a court will
look to the notice given the debtor and the method, manner, time, place and
terms of the sale and the sale price. Generally, a sale conducted according to
the usual practice of creditors selling similar collateral will be considered
reasonably conducted.
 
    Article 9 of the UCC provides that the proceeds of the sale will be applied
first to pay the costs and expenses of the sale and then to satisfy the
indebtedness secured by the lender's security interest. The recognition
agreement, however, generally provides that the lender's right to reimbursement
is subject to the right of the Cooperative corporation to receive sums due under
the proprietary lease or occupancy agreement. If there are proceeds remaining,
the lender must account to the tenant-stockholder for the surplus. Conversely,
if a portion of the indebtedness remains unpaid, the tenant-stockholder is
generally responsible for the deficiency. See "--Anti-Deficiency Legislation and
Other Limitations on Lenders" below.
 
RIGHTS OF REDEMPTION
 
    In some states, after sale pursuant to a deed of trust or foreclosure of the
mortgage, there are statutory periods during which the mortgagor and foreclosed
junior lienors may redeem the property from the foreclosure sale. One effect of
the statutory right of redemption is to diminish the ability of the lender to
sell the foreclosed property because the right of redemption would defeat the
title of any purchaser from the lender subsequent to foreclosure or sale under a
deed of trust. As a practical matter, the lender may therefore be forced to
retain the property and pay the expenses of ownership until the redemption
period has run.
 
ANTI-DEFICIENCY LEGISLATION AND OTHER LIMITATIONS ON
  LENDERS
 
    Certain states have imposed statutory prohibitions which restrict or
eliminate the remedies of a lender under a deed of trust or a mortgage. In some
states, statutes limit the right of the lender to obtain a deficiency judgment
against the mortgagor following sale under a deed of trust or foreclosure. A
deficiency judgment would be a personal judgment against the former mortgagor
equal in most cases to the difference between the net amount realized upon the
public sale of the real property and the amount due to the lender. Other
statutes may require the lender to exhaust the security afforded under a deed of
trust or mortgage by foreclosure in an attempt to satisfy the full debt before
bringing a personal action against the mortgagor. Some state statutes also
prohibit any deficiency judgment where the loan proceeds were used to purchase
an owner-occupied dwelling. Finally, other statutory provisions limit any
deficiency judgment against the former mortgagor following a judicial sale to
the excess of the outstanding debt over the fair market value of the property at
the time of the public sale. The basic purpose of these statutes is to prevent a
lender from obtaining a large deficiency judgment against the former mortgagor
as a result of low or no bids at the judicial sale.
 
    Generally, Article 9 of the UCC governs foreclosure on Cooperative shares
and the related proprietary lease or occupancy agreement. Some courts have
interpreted Article 9 to prohibit or limit a deficiency award in certain
circumstances, including circumstances where the disposition of the collateral
(which, in the case of a Cooperative Loan, would be the shares of the
Cooperative and the related proprietary lease or occupancy agreement) was not
conducted in a commercially reasonable manner.
 
    In addition to anti-deficiency and related legislation, numerous other
statutory provisions, including the federal bankruptcy laws and state laws
affording relief to debtors, may interfere with or affect the ability of the
secured mortgage lender to collect the full amount of interest due or realize
upon its security. For example, with respect to federal bankruptcy law, a court
with federal bankruptcy
 
                                       56
<PAGE>
jurisdiction may permit a mortgagor through his or her Chapter 11, Chapter 12 or
Chapter 13 rehabilitative plan to cure a monetary default in respect of a
mortgage loan on the mortgagor's residence by paying arrearages within a
reasonable time period and reinstating the original mortgage loan payment
schedule even though the lender accelerated the mortgage loan and foreclosure
proceedings had occurred prior to the filing of the debtor's petition. Some
courts with federal bankruptcy jurisdiction have approved plans, based on the
particular facts of the reorganization case, that effected the curing of a
mortgage loan default by paying arrearages over a number of years.
 
    Courts with federal bankruptcy jurisdiction have also held that the terms of
a mortgage loan secured by property of the mortgagor may be modified. These
courts have held that such modifications may include reducing the amount of each
monthly payment, changing the rate of interest, altering the repayment schedule,
and reducing the lender's security interest to the value of the residence, thus
leaving the lender in the position of a general unsecured creditor for the
difference between the value of the residence and the outstanding balance of the
loan. Courts with federal bankruptcy jurisdiction similarly may be able to
modify the terms of a Cooperative Loan.
 
    The Code provides priority to certain tax liens over the lien of the
security instrument. Numerous federal and some state consumer protection laws
impose substantive requirements upon lenders in connection with the origination
and the servicing of mortgage loans. These laws include the federal
Truth-in-Lending Act, Real Estate Settlement Procedures Act, Equal Credit
Opportunity Act, Fair Credit Billing Act, Fair Credit Reporting Act and related
statutes. These federal laws impose specific statutory liabilities upon lenders
who originate mortgage loans and who fail to comply with the provisions of the
law. In some cases, this liability may affect assignees of the mortgage loans.
 
ENFORCEABILITY OF CERTAIN PROVISIONS
 
    The standard forms of note, mortgage and deed of trust used by lenders
generally contain "due-on-sale" clauses. These clauses permit the lender to
accelerate the maturity of the loan if the mortgagor sells, transfers or conveys
the property. The enforceability of these clauses was the subject of legislation
and litigation in many states, and in some cases the enforceability of these
clauses was limited or denied. However, the Garn-St Germain Depository
Institutions Act of 1982 (the "Garn-St Germain Act") purports to pre-empt state
statutory and case law that prohibits the enforcement of "due-on-sale" clauses
and permits lenders to enforce these clauses in accordance with their terms,
subject to certain limited exceptions. The Garn-St Germain Act does "encourage"
lenders to permit assumption of loans at the original rate of interest or at
some other rate less than the average of the original rate and the market rate.
In addition, certain states have continuing restrictions on the enforceability
of due-on-sale clauses for certain loans.
 
    The Garn-St Germain Act also sets forth nine specific instances in which a
mortgage lender covered by the act (including federal savings associations and
federal savings banks) may not exercise a "due-on-sale" clause, notwithstanding
the fact that a transfer of the property may have occurred. These include
intrafamily transfers, certain transfers by operation of law, leases of less
than three years and the creation of a junior encumbrance. Regulations
promulgated under the Garn-St Germain Act by the Federal Home Loan Bank Board
(now the Office of Thrift Supervision) and statutes in some states also prohibit
the imposition of a prepayment penalty upon the acceleration of a loan pursuant
to a "due-on-sale" clause. In addition, a few states have exercised their rights
under the Garn-St Germain Act to limit the enforceability of the due-on-sale
clauses in certain loans made prior to passage of the Garn-St Germain Act. As of
the date hereof, certain states have taken action to reimpose interest rate
limits and/or to limit discount points or other charges.
 
    A consequence of the inability to enforce a due-on-sale clause may be that a
mortgagor's buyer may assume the existing mortgage loan rather than paying it
off, if such existing loan bears an interest rate below the current market rate,
which may have an impact upon the average life of the Mortgage Loans and the
number of Mortgage Loans which may be outstanding until maturity.
 
    Under the terms of the Soldiers' and Sailors' Civil Relief Act of 1940, as
amended (the "Relief Act"), a Mortgagor who enters military service after the
origination of such Mortgagor's Mortgage Loan (including a Mortgagor who is a
member of the National Guard or is in reserve status at the time of the
origination of the Mortgage Loan and is later called to active duty) may not be
charged interest above an annual rate of 6% during the period of such
Mortgagor's active duty status, unless a court
 
                                       57
<PAGE>
orders otherwise upon application of the lender. Any shortfall in interest
collections resulting from the application of the Relief Act, to the extent not
covered by any applicable credit enhancements, could result in losses to the
Holders of the Certificates. In addition, the Relief Act imposes limitations
which would impair the ability of the Servicer to foreclose on an affected
Mortgage Loan during the Mortgagor's period of active duty status. Thus, in the
event that such a Mortgage Loan goes into default, there may be delays and
losses occasioned by the inability to realize upon the Mortgaged Property in a
timely fashion.
 
APPLICABILITY OF USURY LAWS
 
    Title V of the Depository Institutions Deregulation and Monetary Control Act
of 1980, enacted in March 1980 ("Title V"), provides that state usury
limitations shall not apply to certain types of residential first mortgage loans
originated by certain lenders after March 31, 1980. A similar federal statute
was in effect with respect to mortgage loans made during the first three months
of 1980. The Federal Home Loan Bank Board (now the Office of Thrift Supervision)
has issued regulations governing the implementation of Title V. The statute
authorizes any state to reimpose interest rate limits by adopting before April
1, 1983, a law or constitutional provision which expressly rejects application
of the federal law. In addition, even where Title V is not so rejected, any
state is authorized to adopt a provision limiting discount points or other
charges prior to origination on mortgage loans covered by Title V.
 
    Under the Company's mortgage purchase program, each Lender is required to
represent and warrant to the Company that all Mortgage Loans are originated in
full compliance with applicable state laws, including usury laws. Based upon
such representations and warranties from the Lenders, the Company will make a
similar representation and warranty in the Pooling Agreement for each Series to
the Trustee for the benefit of Certificateholders. See "Description of
Certificates-- Representations and Warranties".
 
ALTERNATIVE MORTGAGE INSTRUMENTS
 
    Alternative mortgage instruments, including adjustable-rate mortgage loans,
originated by non-federally chartered lenders have historically been subjected
to a variety of restrictions. Such restrictions differed from state to state,
resulting in difficulties in determining whether a particular alternative
mortgage instrument originated by a state-chartered lender was in compliance
with applicable law. These difficulties were alleviated substantially as a
result of the enactment of Title VIII of the Garn-St Germain Act ("Title VIII").
Title VIII provides that, notwithstanding any state law to the contrary,
state-chartered banks may originate alternative mortgage instruments in
accordance with regulations promulgated by the Comptroller of the Currency with
respect to origination of alternative mortgage instruments by national banks,
state-chartered credit unions may originate alternative mortgage instruments in
accordance with regulations promulgated by the National Credit Union
Administration with respect to origination of alternative mortgage instruments
by federal credit unions, and all other non-federally chartered housing
creditors, including state-chartered savings and loan associations,
state-chartered savings banks and mortgage banking companies, may originate
alternative mortgage instruments in accordance with the regulations promulgated
by the Federal Home Loan Bank Board (now the Office of Thrift Supervision) with
respect to origination of alternative mortgage instruments by federal savings
and loan associations. Title VIII provides that any state may reject
applicability of the provisions of Title VIII by adopting, prior to October 15,
1985, a law or constitutional provision expressly rejecting the applicability of
such provisions. Certain states have taken such action.
 
ENVIRONMENTAL RISKS
 
    Real property pledged as security to a lender may be subject to unforeseen
environmental risks. Under the laws of certain states, contamination of a
property may give rise to a lien on the property to assure the payment of costs
of clean-up. In several states such a lien has priority over the lien of an
existing mortgage against such property. In addition, under the laws of some
states and under the federal Comprehensive Environmental Response, Compensation
and Liability Act of 1980 ("CERCLA"), a lender may be liable, as an "owner" or
"operator", for costs arising out of releases or threatened releases of
hazardous substances that require remedy at a mortgaged property, if agents or
employees of the lender have become sufficiently involved in the operations of
the borrower,
 
                                       58
<PAGE>
regardless of whether or not the environmental damage or threat was caused by a
prior owner. Furthermore, a decision in May 1990 of the United States Court of
Appeals for the Eleventh Circuit in UNITED STATES V. FLEET FACTORS CORP. very
narrowly construed the provision in CERCLA excluding secured lenders from those
who may be liable for remedial costs. In construing the statutory phrase
"without participation in management", which is a qualification for the security
interest exclusion, the court held that a lender need not have involved itself
in the day-to-day operations of the facility or participated in decisions
relating to hazardous waste to be liable; rather, liability could attach to the
lender if its involvement with the management of the facility is broad enough to
support the inference that the lender could affect hazardous waste decisions if
it so chose. The court added that a lender's capacity to influence such
decisions could be inferred from the extent of its involvement in the facility's
financial management. A subsequent decision by the United States Court of
Appeals for the Ninth Circuit in In RE BERGSOE METAL CORP. ruled that a secured
lender had no liability absent "some actual management of the facility" on the
part of the lender. Also, if the lender takes title to or possession of the
property, it may be deemed to have obviated the security interest exclusion and
to be liable for clean-up costs pursuant to CERCLA. If a lender is or becomes
liable, it may be precluded from bringing an action for contribution against the
owner or operator who created the environmental hazard. Such clean-up costs may
be substantial. It is possible that such costs could become a liability of the
related Trust Fund and occasion a loss to Certificateholders in certain
circumstances described above if such remedial costs were incurred.
 
    Except as otherwise specified in the applicable Prospectus Supplement, at
the time the Mortgage Loans were originated, no environmental assessment or a
very limited environment assessment of the Mortgaged Properties will have been
conducted.
 
                              ERISA CONSIDERATIONS
 
    The Employee Retirement Income Security Act of 1974, as amended ("ERISA"),
imposes certain requirements on employee benefit plans and other benefit plans
or arrangements which are subject to ERISA or Section 4975 of the Code ("Plans")
and on those persons who are fiduciaries with respect to Plans or otherwise
responsible for the investment of "plan assets" of Plans ("Plan Assets"). In
accordance with the general fiduciary standards of ERISA, an ERISA Plan
fiduciary should consider whether an investment in the Certificates is permitted
by the documents and instruments governing the Plan, consistent with the Plan's
overall investment policy and appropriate in view of the composition of its
investment portfolio.
 
    Employee benefit plans which are governmental plans (as defined in Section
3(32) of ERISA) and certain church plans (as defined in Section 3(33) of ERISA)
are not subject to the requirements of ERISA or Section 4975 of the Code.
Accordingly, assets of such plans may be invested in the Certificates subject to
the provisions of applicable state law and, in the case of any such plan which
is qualified under Section 401(a) of the Code, the restrictions imposed under
Section 503 of the Code.
 
    In addition to imposing general fiduciary standards, ERISA prohibits a broad
range of transactions involving Plan Assets and certain persons ("Parties in
Interest") who have certain specified relationships to the Plan under Section
406 of ERISA, and taxes any such transaction under Section 4975 of the Code,
unless an exemption applies. If the assets of a Mortgage Pool are treated for
purposes of ERISA and Section 4975 of the Code as Plans or other entities
holding Plan Assets with respect to Plans, collective investment funds,
insurance company general or separate accounts (collectively, "Plan Asset
Investors") that purchase or hold Certificates of the applicable Series, an
investment in Certificates by any such Plan might constitute or give rise to a
prohibited transaction under ERISA or Section 4975 of the Code, unless a
statutory or administrative exemption applies. Violation of the prohibited
transaction rules could result in the imposition of excise taxes and/or other
penalties under ERISA and/or Section 4975 of the Code.
 
PLAN ASSETS REGULATION
 
    The United States Department of Labor ("DOL") has issued a final regulation
(the "Regulation") under which the assets of an entity in which a Plan Asset
Investor makes an equity investment will be treated as Plan Assets in certain
circumstances. Unless the Regulation provides an exemption from this "plan
asset" treatment, and if an exemption is not otherwise available under
 
                                       59
<PAGE>
ERISA, an undivided portion of the assets of a Mortgage Pool will be treated,
for purposes of applying the fiduciary standards and prohibited transaction
rules of ERISA and Section 4975 of the Code, as Plan Assets with respect to each
Plan which becomes a Certificateholder of the applicable Series.
 
    The Regulation provides an exemption from "plan asset" treatment for
securities issued by an entity if, immediately after the most recent acquisition
of any equity interest in the entity, less than 25% of the value of each class
of equity interests in the entity, excluding interests held by a person who has
discretionary authority or control with respect to the assets of the entity (or
any affiliate of such a person), is held by "benefit plan investors" (I.E.,
Plans, governmental, foreign and other employee benefit plans not subject to
ERISA and entities holding Plan Assets). Because the availability of this
exemption with respect to any Mortgage Pool depends upon the identity of the
Certificateholders of the applicable Series at any time, there can be no
assurance as to whether any Series or Class of Certificates will qualify for
this exemption.
 
PROHIBITED TRANSACTION CLASS EXEMPTION 83-1
 
    Prohibited Transaction Class Exemption 83-1 (Class Exemption for Certain
Transactions Involving Mortgage Pool Investment Trusts) ("PTCE 83-1") permits,
subject to certain conditions, certain transactions involving the creation,
maintenance and termination of certain residential mortgage pools and the
acquisition and holding of certain residential mortgage pool pass-through
certificates by Plan Asset Investors, regardless of whether (a) the mortgage
pool is exempt from "plan asset" treatment or (b) the transactions would
otherwise be prohibited under ERISA or Section 4975 of the Code. If the general
conditions (described below) of PTCE 83-1 are satisfied, an investment by a Plan
in Certificates (1) will be exempt from the prohibitions of Section 406(a) of
ERISA (relating generally to Plan Asset transactions involving Parties in
Interest who are not fiduciaries) if the Certificates are purchased at no more
than fair market value, and (2) will be exempt from the prohibitions of Sections
406(b)(1) and (2) of ERISA (relating generally to Plan Asset transactions with
fiduciaries) if, in addition, the purchase is approved by an independent
fiduciary, the Plan Asset Investor pays no more for the Certificates than would
be paid in an arm's length transaction with an unrelated party, no sales
commission is paid to the Company as Mortgage Pool sponsor, the Plan Asset
Investor does not purchase more than 25% of the Certificates of the applicable
Series, and at least 50% of the Certificates of that Series is purchased by
persons independent of the Company, the Trustee and the Insurer, as applicable.
 
    PTCE 83-1 sets forth three general conditions which must be satisfied for
any transaction to be eligible for exemption: (1) the existence of a pool
trustee who is not an affiliate of the pool sponsor; (2) the maintenance of a
system of insurance or other protection for the pooled mortgage loans and
property securing such loans, and for indemnifying certificateholders against
reductions in pass-through payments due to property damage or defaults in loan
payments; and (3) a limitation on the amount of the payment retained by the pool
sponsor, together with other funds inuring to its benefit, to not more than
adequate consideration for selling the mortgage loans plus reasonable
compensation for services provided by the pool sponsor to the mortgage pool.
 
    Unless otherwise specified in the applicable Prospectus Supplement, the
Trustee for each Series will be unaffiliated with the Company, and the first
general condition of PTCE 83-1 will be satisfied for each such Series. With
respect to the second general condition of PTCE 83-1, the Company intends to use
its best efforts to establish for each Series of Certificates an insurance,
indemnification, subordination or other method of credit support which will
adequately protect the Mortgage Pools and indemnify Certificateholders of the
applicable Series against pass-through payment reductions resulting from
property damage or defaults in loan payments. See "Description of Credit
Enhancements". The amount, method and description of the credit support method
applicable to a Series of Certificates will be set forth in the related
Prospectus Supplement. With respect to the third general condition of PTCE 83-1,
the Company intends to use its best efforts to establish for each Series a
compensation method which will produce for the Company total compensation which
will not exceed adequate consideration for forming the Mortgage Pool, selling
the Certificates and serving as Master Servicer of the Mortgage Pool. However,
the Company does not guarantee that its credit support and compensation methods
will be sufficient to meet the second and third general conditions (described
above) with respect to any Series.
 
                                       60
<PAGE>
    As indicated in the two preceding paragraphs, the continued maintenance of a
system of insurance or other protection for the pooled mortgage loans and
property securing such loans, and for indemnifying certificateholders against
reductions in pass-through payments due to property damage or defaults in loan
payments, is one of the three general conditions that must be satisfied for any
transaction involving a Mortgage Pool to remain eligible for exemption by PTCE
83-1 from the prohibited transaction rules of ERISA and Section 4975 of the
Code. If the credit support method established for any Series is cancelled or
terminated, or if the credit support is reduced to such an extent that its
coverage amount is less than the greater of (a) 1% of the aggregate unpaid
principal balance of the Mortgage Loans or (b) the unpaid principal balance of
the largest single Mortgage Loan (see "Description of Credit Enhancements"),
then the Mortgage Pool relating to that Series may no longer satisfy the general
conditions of PTCE 83-1. In such event, the exemption from the prohibited
transaction rules afforded by PTCE 83-1 may no longer be available.
 
    One or more Series of Certificates may be offered to Plan Asset Investors
through a forward delivery commitment contract, which is a contract for the
purchase of Certificates to be delivered at an agreed future settlement date.
PTCE 83-1 permits the sale of Certificates to a Plan Asset Investor pursuant to
such a contract, provided that the forward delivery commitment is expressly
approved by a fiduciary who is independent of the Company, the Trustee, the
Insurer (if any) and their respective affiliates, and who has the authority to
manage and control the Plan Assets being committed for investment in the
Certificates.
 
    PTCE 83-1 will not provide exemptive relief with respect to a Series of
Certificates evidencing interests in Trust Funds that include Cooperative Loans.
If a Series of Certificates is subdivided into two or more Classes which are
entitled to disproportionate allocations of the principal and interest payments
on the Mortgage Loans, the availability of the exemption afforded by PTCE 83-1
may be adversely affected, as described in the applicable Prospectus Supplement.
Moreover, if any Class of Certificates is entitled to pass-through payments of
principal (but no or only nominal interest) or interest (but no or only nominal
principal), PTCE 83-1 will not exempt holders of that Class of Certificates from
the prohibited transaction rules of ERISA and Section 4975 of the Code.
 
OTHER EXEMPTIONS
 
    If for any reason PTCE 83-1 does not provide an exemption for a particular
Certificateholder who is a Plan Asset Investor, one of five other prohibited
transaction class exemptions issued by the DOL might apply, I.E., PTCE 96-23
(Class Exemptions for Plan Asset Transactions Determined by In-House Asset
Managers), PTCE 95-60 (Class Exemption for Certain Transactions Involving
Insurance Company General Accounts), PTCE 91-38 (Class Exemption for Certain
Transactions Involving Bank Collective Investment Funds), PTCE 90-1 (Class
Exemption for Certain Transactions Involving Insurance Company Pooled Separate
Accounts) or PTCE 84-14 (Class Exemption for Plan Asset Transactions Determined
by Independent Qualified Professional Asset Managers). There can be no assurance
that any of these class exemptions will apply with respect to any particular
Plan Asset Investor or, even if it were to apply, that the exemption would apply
to all transactions involving the Mortgage Pool. In addition, the underwriter
with respect to a particular Series may be the recipient of a final prohibited
transaction exemption which, if so specified in the applicable Prospectus
Supplement, may accord a Plan Asset Investor protection from violations of the
prohibited transaction rules of ERISA and Section 4975 of the Code if the Plan
Asset Investor satisfies the conditions described in the applicable Prospectus
Supplement.
 
GENERAL CONSIDERATIONS
 
    In summary, the Company, the Trustee, the Servicer, any insurer, the obligor
under any other credit enhancement instrument, any Seller/Servicer, any
underwriter for any Series of Certificates, as applicable, and their respective
affiliates might be considered or might become Parties in Interest with respect
to a Plan Asset Investor. In that event, the acquisition or holding of
Certificates of the applicable Series or Class by or on behalf of such Plan
Asset Investor might be viewed as giving rise to a prohibited transaction under
ERISA and Section 4975 of the Code, unless PTCE 83-1 or another exemption is
available. Accordingly, before a Plan Asset Investor makes the investment
decision to purchase, to commit to purchase or to hold Certificates of any
Series or Class, the Plan Asset Investor should determine (a) whether the second
and third general conditions and the specific conditions
 
                                       61
<PAGE>
(described briefly above) of PTCE 83-1 have been satisfied; (b) whether adequate
protection is accorded by any prohibited transaction exemption issued to the
underwriter with respect to the applicable Series, as described in the
applicable Prospectus Supplement; (c) whether any other prohibited transaction
class exemption (if required) is available under ERISA and Section 4975 of the
Code; or (d) whether an exemption from "plan asset" treatment is available to
the applicable Mortgage Pool. The Plan Asset Investor should also consult the
ERISA discussion, if any, in the applicable Prospectus Supplement for further
information regarding the application of ERISA and Section 4975 of the Code to
any Series or Class of Certificates.
 
    ANY PLAN ASSET INVESTOR THAT PROPOSES TO USE PLAN ASSETS TO PURCHASE
CERTIFICATES SHOULD CONSULT WITH ITS OWN COUNSEL WITH RESPECT TO THE POTENTIAL
CONSEQUENCES UNDER ERISA AND THE CODE OF THE ACQUISITION AND OWNERSHIP OF
CERTIFICATES.
 
                    CERTAIN FEDERAL INCOME TAX CONSEQUENCES
 
    The following is a general discussion of the anticipated material federal
income tax consequences of the purchase, ownership and disposition of the
Certificates offered hereunder. It does not purport to discuss all federal
income tax consequences that may be applicable to particular categories of
investors, some of which may be subject to special rules and does not address
the tax consequences of persons holding Certificates as part of a hedge or
hedging transaction. Further, the authorities on which this discussion is based
are subject to change or differing interpretations, which changes or differing
interpretations could apply retroactively. This discussion does not address the
state or local tax consequences of the purchase, ownership and disposition of
such Certificates. Investors should consult their own tax advisors in
determining the federal, state, local or other tax consequences to them of the
purchase, ownership and disposition of the Certificates offered hereunder.
 
    The following discussion addresses certificates ("REMIC Certificates")
representing interests in a Mortgage Pool ("REMIC Mortgage Pool") as to which
the Master Servicer will cause to elect treatment as a real estate mortgage
investment conduit ("REMIC") under Sections 860A through 860G ("REMIC
Provisions") of the Code. Under the REMIC Provisions, REMICs may issue "regular"
interests and must issue one and only one class of "residual" interests. A REMIC
Certificate representing a regular interest in a REMIC Mortgage Pool will be
referred to as a "REMIC Regular Certificate" and a REMIC Certificate
representing a residual interest in a REMIC Mortgage Pool will be referred to as
a "REMIC Residual Certificate".
 
    The following discussion is based in part upon the rules governing original
issue discount that are set forth in Code Sections 1271 through 1273 and 1275
and in Treasury regulations issued under the original issue discount provisions
of the Code (the "OID Regulations"), and the Treasury regulations issued under
the provisions of the Code relating to REMICs (the "REMIC Regulations"). The OID
Regulations generally are effective with respect to debt instruments issued on
or after April 4, 1994.
 
  A. CLASSIFICATION OF REMIC TRUST FUNDS
 
    With respect to each Series of REMIC Certificates, Orrick, Herrington &
Sutcliffe, special counsel to the Company, will deliver their opinion generally
to the effect that, assuming (i) a REMIC election is made timely in the required
form, (ii) the Master Servicer complies with all provisions of the related
Pooling Agreement, (iii) certain representations set forth in the Pooling
Agreement are true, and (iv) there is continued compliance with applicable
provisions of the Code, as it may be amended from time to time, and applicable
Treasury regulations issued thereunder, the related REMIC Mortgage Pool will
qualify as a REMIC and the classes of interests offered will be considered to be
regular interests or residual interests in that REMIC Mortgage Pool within the
meaning of the REMIC Provisions.
 
    Holders of REMIC Certificates should be aware that, if an entity electing to
be treated as a REMIC fails to comply with one or more of the ongoing
requirements of the Code for REMIC status during any taxable year, the Code
provides that the entity will not be treated as a REMIC for such year and
thereafter. In such event, an entity electing to be treated as a REMIC may be
taxable as a separate corporation under Treasury regulations, and the related
REMIC Certificates may not be accorded the status described below under the
heading "Characterization of Investments in REMIC Certificates". In the case of
an inadvertent termination of REMIC status, the Code provides the Treasury
 
                                       62
<PAGE>
Department with authority to issue regulations providing relief. Any such
relief, however, may be accompanied by sanctions, such as the imposition of a
corporate tax on all or a portion of the REMIC's income for the period of time
in which the requirements for REMIC status are not satisfied.
 
  B. CHARACTERIZATION OF INVESTMENTS IN REMIC CERTIFICATES
 
    In general, REMIC Certificates are not treated for federal income tax
purposes as ownership interests in the assets of a REMIC Mortgage Pool. However,
with respect to taxable years of a Certificateholder beginning after December
31, 1986, (i) REMIC Certificates held by a mutual savings bank or a domestic
building and loan association will constitute "qualifying real property loans"
within the meaning of Code Section 593(d) in the same proportion that the assets
of the REMIC Mortgage Pool underlying such Certificates ("Assets") would be so
treated; (ii) REMIC Certificates held by a domestic building and loan
association will constitute a "regular or residual interest in a REMIC" within
the meaning of Code Section 7701(a)(19)(C)(xi) in the same proportion that the
Assets would be treated as "loans.......secured by an interest in real property"
within the meaning of
Code Section 7701(a)(19)(C)(v) or as other assets described in Code Section
7701(a)(19)(C); and (iii) REMIC Certificates held by a real estate investment
trust will constitute "real estate assets" within the meaning of Code Section
856(c)(5)(A), and interest on the REMIC Certificates will be considered
"interest on obligations secured by mortgages on real property or on interests
in real property" within the meaning of Code Section 856(c)(3)(B) in the same
proportion that, for both purposes, the Assets would be treated as "interests in
real property" as defined in Code Section 856(c)(6)(C) (or, as provided in the
Committee Report, as "real estate assets" as defined in Code Section
856(c)(6)(B)). See, in this regard, "--Characterization of Investments in Trust
Certificates--Buydown Mortgage Loans", below. Moreover, if 95% or more of the
Assets qualify for any of the foregoing treatments, the REMIC Certificates will
qualify for the corresponding status in their entirety. Investors should be
aware that the investment of amounts in any reserve account in assets not so
qualifying would, and holding property acquired by foreclosure pending sale
might, reduce the amount of the REMIC Certificate that would qualify for the
foregoing treatment. The REMIC Regulations provide that payments on Mortgage
Loans held pending distribution are considered part of the Mortgage Loans for
purposes of Code Sections 593(d) and 856(c)(5)(A); it is unclear whether such
collected payments would be so treated for purposes of Code Section
7701(a)(19)(c)(v), but there appears to be no reason why analogous treatment
should not be given to such collected payments under that provision. The
determination as to the percentage of the REMIC's assets that will constitute
assets described in the foregoing sections of the Code will be made with respect
to each calendar quarter based on the average adjusted basis of each category of
the assets held by the REMIC during such calendar quarter. The REMIC will report
those determinations to Certificateholders in the manner and at the times
required by applicable Treasury regulations. The applicable Prospectus
Supplement or the related Current Report on Form 8-K for each Series of REMIC
Certificates will describe the Assets as of the Cut-Off Date. REMIC Certificates
held by certain financial institutions will constitute "evidence of
indebtedness" within the meaning of Code Section 582(c)(1); in addition, REMIC
Regular Certificates acquired by a REMIC in accordance with the requirements of
Section 860G(a)(3)(C) or Section 860G(a)(4)(B) of the Code will be treated as
"qualified mortgages" for purposes of Code Section 860D(a)(4).
 
  C. TAXATION OF OWNERS OF REMIC REGULAR CERTIFICATES
 
    Except as otherwise stated in this discussion, the REMIC Regular
Certificates will be treated for federal income tax purposes as debt instruments
issued by the REMIC Mortgage Pool and not as ownership interests in the REMIC
Mortgage Pool or its Assets. In general, interest, original issue discount and
market discount paid or accrued on a REMIC Regular Certificate will be treated
as ordinary income to the holder of such REMIC Regular Certificate.
Distributions in reduction of the stated redemption price at maturity of the
REMIC Regular Certificate will be treated as a return of capital to the extent
of such holder's basis in such REMIC Regular Certificate. Holders of REMIC
Regular Certificates that otherwise report income under a cash method of
accounting will be required to report income with respect to REMIC Regular
Certificates under an accrual method.
 
                                       63
<PAGE>
   1. ORIGINAL ISSUE DISCOUNT
 
    Certain REMIC Regular Certificates may be issued with "original issue
discount" within the meaning of Code Section 1273(a). Any holders of REMIC
Regular Certificates issued with original issue discount generally will be
required to include original issue discount in income as it accrues, in
accordance with a constant interest method that takes into account the
compounding of interest, in advance of the receipt of the cash attributable to
such income. The Company will report annually (or more often if required) to the
Internal Revenue Service ("IRS") and to Certificateholders such information with
respect to the original issue discount accruing on the REMIC Regular
Certificates as may be required under Code Section 6049 and the regulations
thereunder. See "--Reporting and Other Administrative Matters of REMICS" below.
 
    Rules governing original issue discount are set forth in Code Sections 1271
through 1273 and 1275 and, to some extent, in the OID Regulations. Code Section
1272(a)(6) provides special original issue discount rules applicable to REMIC
Regular Certificates. Regulations have not yet been proposed or adopted under
Section 1272(a)(6) of the Code. Further, application of the OID Regulations to
the REMIC Regular Certificates remains unclear in some respects because the OID
Regulations generally purport not to apply to instruments to which section
1272(a)(6) applies such as REMIC Regular Certificates, and separately because
they either do not address, or are subject to varying interpretations with
regard to, several relevant issues.
 
    Code Section 1272(a)(6) requires that a mortgage prepayment assumption
("Prepayment Assumption") be used in computing the accrual of original issue
discount on REMIC Regular Certificates and for certain other federal income tax
purposes. The Prepayment Assumption is to be determined in the manner prescribed
in Treasury regulations. To date, no such regulations have been promulgated. The
Committee Report indicates that the regulations will provide that the Prepayment
Assumption, if any, used with respect to a particular transaction must be the
same as that used by the parties in pricing the transaction. Unless otherwise
specified in the applicable Prospectus Supplement, the Company will use a
percentage of the Basic Prepayment Assumption (or such other Prepayment
Assumption as may be specified in the applicable Prospectus Supplement) in
reporting original issue discount that is consistent with this standard.
However, the Company does not make any representation that the Mortgage Loans
will in fact prepay at that percentage of the Basic Prepayment Assumption or at
any other rate. Each investor must make its own decision as to the
appropriate prepayment assumption to be used in deciding whether or not to
purchase any of the REMIC Regular Certificates. The Prospectus Supplement with
respect to a Series of REMIC Certificates will disclose the percentage of the
Basic Prepayment Assumption (or such other Prepayment Assumption as may be
specified therein) to be used in reporting original issue discount, if any, and
for certain other federal income tax purposes.
 
    The total amount of original issue discount on a REMIC Regular Certificate
is the excess of the "stated redemption price at maturity" of the REMIC Regular
Certificate over its "issue price". Except as discussed in the following two
paragraphs, in general, the issue price of a particular Class of REMIC Regular
Certificates offered hereunder will be the price at which a substantial amount
of REMIC Regular Certificates of that Class are first sold to the public
(excluding bond houses and brokers).
 
    If a REMIC Regular Certificate is sold with accrued interest that relates to
a period prior to the issue date of such REMIC Regular Certificate, the amount
paid for the accrued interest will be treated instead as increasing the issue
price of the REMIC Regular Certificate. In addition, that portion of the first
interest payment in excess of interest accrued from the Closing Date to the
first Distribution Date will be treated for federal income tax reporting
purposes as includible in the stated redemption price at maturity of the REMIC
Regular Certificate, and as excludible from income when received as a payment of
interest on the first Distribution Date. The OID Regulations suggest that some
or all of this pre-issuance accrued interest "may" be treated as a separate
asset (and hence not includible in a REMIC Regular Certificate's issue price or
stated redemption price at maturity), whose cost is recovered entirely out of
interest paid on the first Distribution Date. It is unclear how such treatment
would be elected under the OID Regulations and whether an election could be made
unilaterally by a Certificateholder.
 
                                       64
<PAGE>
    The stated redemption price at maturity of a REMIC Regular Certificate is
equal to the total of all payments to be made on such Certificate other than
"qualified stated interest." Under the OID Regulations, "qualified stated
interest" is interest that is unconditionally payable at least annually during
the entire term of the Certificate at either (i) a single fixed rate that
appropriately takes into account the length of the interval between payments or
(ii) the current values of a single "qualified floating rate" or "objective
rate" (each, a "Single Variable Rate"). A "current value" is the value of a
variable rate on any day that is no earlier than three months prior to the first
day on which that value is in effect and no later than one year following that
day. A "qualified floating rate" is a rate whose variations can reasonably be
expected to measure contemporaneous variations in the cost of newly borrowed
funds in the currency in which the Certificate is denominated. Such a rate
remains qualified even though it is multiplied by a fixed, positive multiple not
exceeding 1.35, increased or decreased by a fixed rate, or both. Certain
combinations of rates constitute a single qualified floating rate, including (i)
interest stated at a fixed rate for an initial period of less than one year
followed by a qualified floating rate if the value of the floating rate at the
closing date is intended to approximate the fixed rate, and (ii) two or more
qualified floating rates that can be expected to have approximately the same
values throughout the term of the Certificate. A combination of such rates is
conclusively presumed to be a single floating rate if the values of all rates on
the closing date are within 0.25% of each other. A variable rate that is subject
to an interest rate cap, floor, "governor" or similar restriction on rate
adjustment may be a qualified floating rate only if such restriction is fixed
throughout the term of the instrument, or is not reasonably expected as of the
closing date to cause the yield on the debt instrument to differ significantly
from the expected yield absent the restriction. An "objective rate" is a rate
(other than a qualified floating rate) determined using a single formula fixed
for the life of the Certificate, which is based on (i) one or more qualified
floating rates (including a multiple or inverse of a qualified floating rate),
(ii) one or more rates each of which would be a qualified floating rate for a
debt instrument denominated in a foreign currency, (iii) the yield or changes in
price of one or more items of "actively traded" personal property, (iv) a
combination of rates described in (i), (ii) and (iii), or (v) a rate designated
by the IRS. However, a variable rate is not an objective rate if it is
reasonably expected that the average value of the rate during the first half of
the Certificate's term will differ significantly from the average value of such
rate during the final half of its term. A combination of interest stated at a
fixed rate for an initial period of less than one year followed by an objective
rate is treated as a single objective rate if the value of the objective rate at
the closing date is intended to approximate the fixed rate; such a combination
of rates is conclusively presumed to be a single objective rate if the objective
rate on the closing date does not differ from the fixed rate by more than 0.25%.
The qualified stated interest payable with respect to certain variable rate debt
instruments not bearing stated interest at a Single Variable Rate generally is
determined under the OID Regulations by converting such instruments into fixed
rate debt instruments. Instruments qualifying for such treatment generally
include those providing for stated interest at (i) more than one qualified
floating rates, or at (ii) a single fixed rate and (a) one or more qualified
floating rates or (b) a single "qualified inverse floating rate" (each, a
"Multiple Variable Rate"). A qualified inverse floating rate is an objective
rate equal to a fixed rate reduced by a qualified floating rate, the variations
in which can reasonably be expected to inversely reflect contemporaneous
variations in the cost of newly borrowed funds (disregarding permissible rate
caps, floors, governors and similar restrictions such as are described above).
Under these rules, some of the payments of interest on a Certificate bearing a
fixed rate of interest for an initial period followed by a qualified floating
rate of interest in subsequent periods could be treated as included in the
stated redemption price at maturity if the initial fixed rate were to differ
sufficiently from the rate that would have been set using the formula applicable
to subsequent periods. See "--Variable Rate Certificates". REMIC Regular
Certificates offered hereby other than Certificates providing for variable rates
of interest or for the accretion of interest are not anticipated to have stated
interest other than "qualified stated interest", but if any such REMIC Regular
Certificates are so offered, appropriate disclosures will be made in the
Prospectus Supplement. Some or all of the payments on REMIC Regular Certificates
providing for the accretion of interest will be included in the stated
redemption price at maturity of such Certificates.
 
    Under a DE MINIMIS rule in the Code, as interpreted in the OID Regulations,
original issue discount on a REMIC Regular Certificate will be considered to be
zero if such original issue discount is less than 0.25% of the stated redemption
price at maturity of the REMIC Regular Certificate multiplied by the weighted
average life of the REMIC Regular Certificate. For this purpose, the
 
                                       65
<PAGE>
weighted average life of the REMIC Regular Certificate is computed as the sum of
the amounts determined by multiplying the amount of each payment under the
instrument (other than a payment of qualified stated interest) by a fraction,
whose numerator is the number of complete years from the issue date until such
payment is made, and whose denominator is the stated redemption price at
maturity of such REMIC Regular Certificate. The IRS may be anticipated to take
the position that this rule should be applied taking into account the Prepayment
Assumption and the effect of any anticipated investment income. Under the OID
Regulations, REMIC Regular Certificates bearing only qualified stated interest
except for any "teaser" rate, interest holiday or similar provision would be
treated as subject to the DE MINIMIS rule if the greater of the deferred or
foregone interest or the other original issue discount is less than such DE
MINIMIS amount.
 
    The OID Regulations generally would treat DE MINIMIS original issue discount
as includible in income as each principal payment is made, based on the product
of the total amount of such DE MINIMIS original issue discount and a fraction,
whose numerator is the amount of such principal payment and whose denominator is
the stated principal amount of the REMIC Regular Certificate. The OID
Regulations also would permit a Certificateholder to elect to accrue DE MINIMIS
original issue discount into income currently based on a constant yield method.
See "Taxation of Owners of REMIC Regular Certificates--Market Discount and
Premium".
 
    Each holder of a REMIC Regular Certificate must include in gross income the
sum of the "daily portions" of original issue discount on its REMIC Regular
Certificate for each day during its taxable year on which it held such REMIC
Regular Certificate. For this purpose, in the case of an original holder of a
REMIC Regular Certificate, the daily portions of original issue discount will be
determined as follows. A calculation will first be made of the portion of the
original issue discount that accrued during each accrual period, that is, unless
otherwise stated in the applicable Prospectus Supplement, each period that
begins or ends on a date that corresponds to a Distribution Date on the REMIC
Regular Certificate and begins on the first day following the immediately
preceding accrual period (beginning on the Closing Date in the case of the first
such period). For any accrual period such portion will equal the excess, if any,
of (i) the sum of (A) the present value of all of the distributions remaining to
be made on the REMIC Regular Certificate, if any, as of the end of the accrual
period and (B) the distribution made on such REMIC Regular Certificate during
the accrual period of amounts included in the stated redemption price at
maturity, over (ii) the adjusted issue price of such REMIC Regular Certificate
at the beginning of the accrual period. The present value of the remaining
payments referred to in the preceding sentence will be calculated based on (i)
the yield to maturity of the REMIC Regular Certificate, calculated as of the
settlement date, giving effect to the Prepayment Assumption, (ii) events
(including actual prepayments) that have occurred prior to the end of the
accrual period, and (iii) the Prepayment Assumption. The adjusted issue price of
a REMIC Regular Certificate at the beginning of any accrual period will equal
the issue price of such Certificate, increased by the aggregate amount of
original issue discount with respect to such REMIC Regular Certificate that
accrued in prior accrual periods, and reduced by the amount of any distributions
made on such REMIC Regular Certificate in prior accrual periods of amounts
included in the stated redemption price at maturity. The original issue discount
accruing during any accrual period will be allocated ratably to each day during
the period to determine the daily portion of original issue discount for each
day. With respect to an accrual period between the settlement date and the first
Distribution Date on the REMIC Regular Certificate (notwithstanding that no
distribution is scheduled to be made on such date) that is shorter than a full
accrual period, the OID Regulations permit the daily portions of original issue
discount to be determined according to any reasonable method.
 
    A subsequent purchaser of a REMIC Regular Certificate that purchases such
REMIC Regular Certificate at a cost (not including payment for accrued qualified
stated interest) less than its remaining stated redemption price at maturity
will also be required to include in gross income, for each day on which it holds
such REMIC Regular Certificate, the daily portions of original issue discount
with respect to such REMIC Regular Certificate, but reduced, if such cost
exceeds the "adjusted issue price", by an amount equal to the product of (i)
such daily portions and (ii) a constant fraction, whose numerator is such excess
and whose denominator is the sum of the daily portions of original issue
discount on such REMIC Regular Certificate for all days on or after the day of
purchase. The adjusted issue price of a REMIC Regular Certificate on any given
day is equal to the sum of the adjusted issue price (or, in the case of the
first accrual period, the issue price) of the REMIC Regular
 
                                       66
<PAGE>
Certificate at the beginning of the accrual period during which such day occurs
and the daily portions of original issue discount for all days during such
accrual period prior to such day, reduced by the aggregate amount of
distributions previously made other than distributions of qualified stated
interest.
 
    VARIABLE RATE CERTIFICATES.  Purchasers of REMIC Regular Certificates
bearing a variable rate of interest should be aware that there is uncertainty
concerning the application of Section 1272(a)(6) of the Code and the OID
Regulations to such Certificates. In the absence of other authority, the Company
intends to be guided by the provisions of the OID Regulations governing variable
rate debt instruments in adapting the provisions of Section 1272(a)(6) of the
Code to such Certificates for the purpose of preparing reports furnished to
Certificateholders. The effect of the application of such provisions generally
will be to cause Certificateholders holding Certificates bearing interest at a
Single Variable Rate to take into account for each period an amount
corresponding approximately to the sum of (i) the qualified stated interest,
accruing on the outstanding face amount of the REMIC Regular Certificate as the
stated interest rate for that Certificate varies from time to time and (ii) the
amount of original issue discount that would have been attributable to that
period on the basis of a constant yield to maturity for a bond issued at the
same time and issue price as the REMIC Regular Certificate, having the same face
amount and schedule of payments of principal as such Certificate, subject to the
same Prepayment Assumption, and bearing interest at a fixed rate equal to the
value of the applicable qualified floating rate or qualified inverse floating
rate in the case of a Certificate providing for either such rate, or equal to
the fixed rate that reflects the reasonably expected yield on the Certificate in
the case of a Certificate providing for an objective rate other than an inverse
floating rate, in each case as of the issue date. Certificateholders holding
REMIC Regular Certificates bearing interest at a Multiple Variable Rate
generally will take into account interest and original issue discount under a
similar methodology, except that the amounts of qualified stated interest and
original issue discount attributable to such a Certificate first will be
determined for an equivalent fixed rate debt instrument, the assumed fixed rates
for which are (a) for each qualified floating rate, the value of each such rate
as of the closing date (with appropriate adjustment for any differences in
intervals between interest adjustment dates), (b) for a qualified inverse
floating rate, the value of the rate as of the closing date, (c) for any other
objective rate, the fixed rate that reflects the yield that is reasonably
expected for the Certificate, and (d) for an actual fixed rate, such
hypothetical fixed rate as would result under (a) or (b) if the actual fixed
rate were replaced by a hypothetical qualified floating rate or qualified
inverse floating rate such that the fair market value of the Certificate as of
the issue date would be approximately the same as that of an otherwise identical
debt instrument providing for the hypothetical variable rate rather than the
actual fixed rate. If the interest paid or accrued with respect to a Multiple
Variable Rate Certificate during an accrual period differs from the assumed
fixed interest rate, such difference will be an adjustment (to interest or
original issue discount, as applicable) to the Certificateholder's taxable
income for the taxable period or periods to which such difference relates.
Additionally, purchasers of such Certificates should be aware that the
provisions of the OID Regulations applicable to variable rate debt instruments
have been limited and may not apply to some REMIC Regular Certificates having
variable rates. If such a Certificate is not governed by the provisions of the
OID Regulations applicable to variable rate debt instruments, it may be subject
to provisions of proposed Treasury Regulations applicable to instruments having
contingent payments. The application of those provisions to instruments such as
variable rate REMIC Regular Certificates is subject to differing
interpretations. Prospective purchasers of variable rate REMIC Regular
Certificates are advised to consult their tax advisors concerning the tax
treatment of such Certificates.
 
   2. MARKET DISCOUNT AND PREMIUM
 
    A Certificateholder that purchases a REMIC Regular Certificate at a market
discount, that is, at a purchase price less than the adjusted issue price (as
defined under "--Taxation of Owners of REMIC Regular Certificates--Original
Issue Discount") of such REMIC Regular Certificate generally will recognize
market discount upon receipt of each distribution of principal. In particular,
such a holder will generally be required to allocate each payment of principal
on a REMIC Regular Certificate first to accrued market discount, and to
recognize ordinary income to the extent such principal payment does not exceed
the aggregate amount of accrued market discount on such REMIC Regular
Certificate not previously included in income. Such market discount must be
included in income in addition to any original issue discount includible in
income with respect to such REMIC Regular Certificate.
 
                                       67
<PAGE>
    A Certificateholder may elect to include market discount in income currently
as it accrues, rather than including it on a deferred basis in accordance with
the foregoing. If made, such election will apply to all market discount bonds
acquired by such Certificateholder on or after the first day of the first
taxable year to which such election applies. In addition, the OID Regulations
permit a Certificateholder to elect to accrue all interest, discount (including
DE MINIMIS market or original issue discount) and premium in income as interest,
based on a constant yield method. If such an election were made for a REMIC
Regular Certificate with market discount, the Certificateholder would be deemed
to have made an election to currently include market discount in income with
respect to all other debt instruments having market discount that such
Certificateholder acquires during the year of the election or thereafter.
Similarly, a Certificateholder that makes this election for a Certificate that
is acquired at a premium is deemed to have made an election to amortize bond
premium, as described below, with respect to all debt instruments having
amortizable bond premium that such Certificateholder owns or acquires. The
election to accrue interest, discount and premium on a constant yield method
with respect to a Certificate is irrevocable.
 
    Under a statutory DE MINIMIS exception, market discount with respect to a
REMIC Regular Certificate will be considered to be zero for purposes of Code
Sections 1276 through 1278 if such market discount is less than 0.25% of the
stated redemption price at maturity of such REMIC Regular Certificate multiplied
by the number of complete years to maturity remaining after the date of its
purchase. In interpreting a similar DE MINIMIS rule with respect to original
issue discount on obligations payable in installments, the OID Regulations refer
to the weighted average maturity of obligations, and it is likely that the same
rule will be applied in determining whether market discount is DE MINIMIS. It
appears that DE MINIMIS market discount on a REMIC Regular Certificate would be
treated in a manner similar to original issue discount of a DE MINIMIS amount.
See "Taxation of Holders of REMIC Regular Certificates--Original Issue
Discount". Such treatment would result in discount being included in income at a
slower rate than discount would be required to be included using the method
described above. However, Treasury regulations implementing the market discount
DE MINIMIS exception have not been issued in proposed or temporary form, and the
precise treatment of DE MINIMIS market discount on obligations payable in more
than one installment therefore remains uncertain.
 
    The 1986 Act grants authority to the Treasury Department to issue
regulations providing for the method for accruing market discount of more than a
DE MINIMIS amount on debt instruments, the principal of which is payable in more
than one installment. Until such time as regulations are issued by the Treasury
Department, certain rules described in the Committee Report will apply. Under
those rules, the holder of a bond purchased with more than DE MINIMIS market
discount may elect to accrue such market discount either on the basis of a
constant yield method or on the basis of the appropriate proportionate method
described below. Under the proportionate method for obligations issued with
original issue discount, the amount of market discount that accrues during a
period is equal to the product of (i) the total remaining market discount,
multiplied by (ii) a fraction, the numerator of which is the original issue
discount accruing during the period and the denominator of which is the total
remaining original issue discount at the beginning of the period. Under the
proportionate method for obligations issued without original issue discount, the
amount of market discount that accrues during a period is equal to the product
of (i) the total remaining market discount, multiplied by (ii) a fraction, the
numerator of which is the amount of stated interest paid during the accrual
period and the denominator of which is the total amount of stated interest
remaining to be paid at the beginning of the period. The Prepayment Assumption,
if any, used in calculating the accrual of original issue discount is to be used
in calculating the accrual of market discount under any of the above methods.
Because the regulations referred to in this paragraph have not been issued, it
is not possible to predict what effect such regulations might have on the tax
treatment of a REMIC Regular Certificate purchased at a discount in the
secondary market.
 
    Further, a purchaser generally will be required to treat a portion of any
gain on sale or exchange of a REMIC Regular Certificate as ordinary income to
the extent of the market discount accrued to the date of disposition under one
of the foregoing methods, less any accrued market discount previously reported
as ordinary income. Such purchaser also may be required to defer a portion of
its interest deductions for the taxable year attributable to any indebtedness
incurred or continued to purchase or carry such REMIC Regular Certificate. Any
such deferred interest expense is, in general, allowed as a
 
                                       68
<PAGE>
deduction not later than the year in which the related market discount income is
recognized. If such holder elects to include market discount in income currently
as it accrues on all market discount instruments acquired by such holder in that
taxable year or thereafter, the interest deferral rule described above will not
apply.
 
    A REMIC Regular Certificate purchased at a cost (not including payment for
accrued qualified stated interest) greater than its remaining stated redemption
price at maturity will be considered to be purchased at a premium. The holder of
such a REMIC Regular Certificate may elect to amortize such premium under the
constant yield method. The OID Regulations also permit Certificateholders to
elect to include all interest, discount and premium in income based on a
constant yield method, further treating the Certificateholder as having made the
election to amortize premium generally, as discussed above. The Committee Report
indicates a Congressional intent that the same rules that will apply to accrual
of market discount on installment obligations will also apply in amortizing bond
premium under Code Section 171 on installment obligations such as the REMIC
Regular Certificates.
 
   3. REALIZED LOSSES
 
    Under Code Section 166, both corporate holders of REMIC Regular Certificates
and noncorporate holders of REMIC Regular Certificates that acquire such
Certificates in connection with a trade or business should be allowed to deduct,
as ordinary losses, any losses sustained during a taxable year in which their
Certificates become wholly or partially worthless as a result of one or more
realized losses on the Mortgage Loans. However, it appears that a noncorporate
holder that does not acquire a REMIC Regular Certificate in connection with a
trade or business will not be entitled to deduct a loss under Code Section 166
until such holder's Certificate becomes wholly worthless (I.E., until its
outstanding principal balance has been reduced to zero) and that the loss will
be characterized as a short-term capital loss.
 
    Each holder of a REMIC Regular Certificate will be required to accrue
interest and original issue discount with respect to such Certificate without
regard to any reduction in distributions attributable to defaults or
delinquencies on the Mortgage Loans or the underlying assets until it can be
established that any such reduction ultimately will not be recoverable. As a
result, the amount of taxable income reported in any period by the holder of a
REMIC Regular Certificate could exceed the amount of economic income actually
realized by the holder in such period. Although the holder of a REMIC Regular
Certificate eventually will recognize a loss or reduction in income attributable
to previously accrued and included income that, as a result of a realized loss,
ultimately will not be realized, the law is unclear with respect to the timing
and character of such loss or reduction in income.
 
  D. TAXATION OF OWNERS OF REMIC RESIDUAL CERTIFICATES
 
   1. GENERAL
 
    An owner of a REMIC Residual Certificate ("Residual Owner") generally will
be required to report its daily portion of the taxable income or, subject to the
limitation described below in "--Taxation of Owners of REMIC Residual
Certificates--Basis Rules and Distributions", the net loss of the REMIC Mortgage
Pool for each day during a calendar quarter that the Residual Owner owned such
REMIC Residual Certificate. For this purpose, the daily portion will be
determined by allocating to each day in the calendar quarter, using a 30 days
per month/90 days per quarter/360 days per year counting convention (unless
otherwise disclosed in the applicable Prospectus Supplement), its ratable
portion of the taxable income or net loss of the REMIC Mortgage Pool for such
quarter, and by allocating the daily portions among the Residual Owners (on such
day) in accordance with their percentage of ownership interests on such day. Any
amount included in the gross income or allowed as a loss of any Residual Owner
by virtue of this paragraph will be treated as ordinary income or loss.
Purchasers of REMIC Residual Certificates should be aware that taxable income
from such Certificates could exceed cash distributions thereon in any taxable
year. For example, if Mortgage Loans are acquired by a REMIC at a discount, then
the holder of a residual interest may recognize income without corresponding
cash distributions. This result could occur because a payment produces
recognition of discount on the Mortgage Loan while the payment could be used in
whole or in part to make principal payments on REMIC Regular Certificates issued
without substantial discount. Taxable income may also be greater in earlier
years as a result of the fact that interest expense
 
                                       69
<PAGE>
deductions, expressed as a percentage of the outstanding principal amount of the
REMIC Regular Certificates, will increase over time as the lower yielding
sequences of Certificates are paid, whereas interest income with respect to any
given fixed rate Mortgage Loan will remain constant over time as a percentage of
the outstanding principal amount of that loan.
 
    Any payments received by a holder of a REMIC Residual Certificate in
connection with the acquisition of such Certificate will be taken into account
in determining the income of such holder for federal income tax purposes.
Although it appears likely that any such payment would be includible in income
immediately upon its receipt, the IRS might assert that such payment should be
included in income over time according to an amortization schedule or according
to some other method. Because of the uncertainty concerning the treatment of
such payments, holders of REMIC Residual Certificates should consult their tax
advisors concerning the treatment of such payments for income tax purposes.
 
   2. TAXABLE INCOME OR NET LOSS OF THE REMIC TRUST FUND
 
    The taxable income or net loss of the REMIC Mortgage Pool will reflect a
netting of income from the Mortgage Loans, any cancellation of indebtedness
income due to the allocation of Realized Losses to REMIC Regular Certificates,
and deductions and losses allowed to the REMIC Mortgage Pool. Such taxable
income or net loss for a given calendar quarter will be determined in the same
manner as for an individual having the calendar year as his taxable year and
using the accrual method of accounting, with certain modifications. The first
modification is that a deduction will be allowed for accruals of interest
(including original issue discount) on the REMIC Regular Certificates. Second,
market discount equal to the excess of any Mortgage Loan's adjusted issue price
(as determined under "Taxation of Owners of REMIC Regular Certificates--Market
Discount and Premium") over its fair market value at the time of their transfer
to the REMIC Mortgage Pool generally will be included in income as it accrues,
based on a constant yield and on the Prepayment Assumption. For this purpose,
the Company intends to treat the fair market value of the Mortgage Loans as
being equal to the aggregate issue prices of the REMIC Regular Certificates and
REMIC Residual Certificates; if one or more classes of REMIC Regular
Certificates or REMIC Residual Certificates are retained by the Company, it will
estimate the value of such retained interests in order to determine the fair
market value of the Mortgage Loans for this purpose. Third, no item of income,
gain, loss or deduction allocable to a prohibited transaction (see "--Prohibited
Transactions and Other Possible REMIC Taxes", below) will be taken into account.
Fourth, the REMIC Mortgage Pool generally may not deduct any item that would not
be allowed in calculating the taxable income of a partnership by virtue of Code
Section 703(a)(2). Fifth, the REMIC Regulations provide that the limitation on
miscellaneous itemized deductions imposed on individuals by Code Section 67 will
not be applied at the Mortgage Pool level to the servicing fees paid to the
Master Servicer or sub-servicers, if any. (See, however, "--Pass-Through of
Servicing Fees", below.) If the deductions allowed to the REMIC Mortgage Pool
exceed its gross income for a calendar quarter, such excess will be the net loss
for the REMIC Mortgage Pool for that calendar quarter.
 
   3. BASIS RULES AND DISTRIBUTIONS
 
    Any distribution by a REMIC Mortgage Pool to a Residual Owner will not be
included in the gross income of such Residual Owner to the extent it does not
exceed the adjusted basis of such Residual Owner's interest in a REMIC Residual
Certificate. Such distribution will reduce the adjusted basis of such interest,
but not below zero. To the extent a distribution exceeds the adjusted basis of
the REMIC Residual Certificate, it will be treated as gain from the sale of the
REMIC Residual Certificate. (See "--Sales of REMIC Certificates", below.) The
adjusted basis of a REMIC Residual Certificate is equal to the amount paid for
such REMIC Residual Certificate, increased by amounts included in the income of
the Residual Owner (See "--Taxation of Owners of REMIC Residual
Certificates--Daily Portions", above) and decreased by distributions and by net
losses taken into account with respect to such interest.
 
    A Residual Owner is not allowed to take into account any net loss for any
calendar quarter to the extent such net loss exceeds such Residual Owner's
adjusted basis in its REMIC Residual Certificate as of the close of such
calendar quarter (determined without regard to such net loss). Any loss
 
                                       70
<PAGE>
disallowed by reason of this limitation may be carried forward indefinitely to
future calendar quarters and, subject to the same limitation, may be used only
to offset income from the REMIC Residual Certificate.
 
    The effect of these basis and distribution rules is that a Residual Owner
may not amortize its basis in a REMIC Residual Certificate, but may only recover
its basis through distributions, through the deduction of any net losses of the
REMIC Mortgage Pool or upon the sale of its REMIC Residual Certificate (See
"--Sales of REMIC Certificates", below). The residual holder does, however,
receive reduced taxable income over the life of the REMIC, because the REMIC's
basis in the underlying REMIC Mortgage Pool includes the fair market value of
the REMIC Regular Certificates and REMIC Residual Certificates.
 
   4. EXCESS INCLUSIONS
 
    Any "excess inclusions" with respect to a REMIC Residual Certificate are
subject to certain special tax rules. With respect to a Residual Owner, the
excess inclusion for any calendar quarter is defined as the excess (if any) of
the daily portions of taxable income over the sum of the "daily accruals" for
each day during such quarter that such REMIC Residual Certificate was held by
such Residual Owner. The daily accruals are determined by allocating to each day
during a calendar quarter its ratable portion of the product of the "adjusted
issue price" of the REMIC Residual Certificate at the beginning of the calendar
quarter and 120 percent of the long-term "applicable federal rate" (generally,
an average of current yields on Treasury securities of comparable maturity) (the
"AFR") in effect at the time of issuance of the REMIC Residual Certificate. For
this purpose, the adjusted issue price of a REMIC Residual Certificate as of the
beginning of any calendar quarter is the issue price of the REMIC Residual
Certificate, increased by the amount of daily accruals for all prior quarters
and decreased by any distributions made with respect to such REMIC Residual
Certificate before the beginning of such quarter. The issue price of a REMIC
Residual Certificate is the initial offering price to the public (excluding bond
houses and brokers) at which a substantial amount of the REMIC Residual
Certificates were sold.
 
    For Residual Owners, other than thrift institutions described in Code
Section 593, an excess inclusion cannot be offset by deductions, losses or loss
carryovers from other activities. For Residual Owners that are subject to tax on
unrelated business taxable income (as defined in Code Section 511), an excess
inclusion of such Residual Owner is treated as unrelated business taxable
income. For Residual Owners that are nonresident alien individuals or foreign
corporations generally subject to United States 30% withholding tax, even if
interest paid to such Residual Owners is generally eligible for exemptions from
such tax, an excess inclusion will be subject to such tax and no tax treaty rate
reduction or exemption may be claimed with respect thereto. See "--Foreign
Investors in REMIC Certificates".
 
    Provisions enacted by the "Technical and Miscellaneous Revenue Act of 1988"
(the "1988 Act") cause the above-described exception for thrift institutions
generally to apply only to those residual interests held and deductions, losses
and loss carryovers incurred directly by such institutions (and not by other
members of an affiliated group of corporations filing a consolidated income tax
return) or certain wholly owned direct subsidiaries of such institutions formed
and operated exclusively in connection with the organization and operation of
one or more REMICs. The REMIC Regulations further limit this exception to
residual interests having "significant value". In order to have significant
value, the REMIC Residual Certificates must have an aggregate issue price, at
issuance, at least equal to two percent of the aggregate issue prices of all of
the related REMIC Regular and Residual Certificates. In addition, the
anticipated weighted average life of the REMIC Residual Certificates must equal
or exceed 20 percent of the anticipated weighted average life of the REMIC,
based on the Prepayment Assumption and on any required or permitted clean up
calls or required liquidation provided for in the REMIC's organizational
documents. Although it has not done so, the Treasury also has authority to issue
regulations that, if REMIC Residual Certificates are found in the aggregate not
to have "significant value", would treat as excess inclusions with respect to
such REMIC Residual Certificates the entire daily portion of taxable income for
such REMIC Residual Certificates. Each Prospectus Supplement pursuant to which
REMIC Residual Certificates are offered will state whether such REMIC Residual
Certificates will have, or may be regarded as having, "significant value" under
the REMIC Regulations; provided, however, that any disclosure that a
 
                                       71
<PAGE>
REMIC Residual Certificate will have "significant value" will be based upon
certain assumptions, and the Company will make no representation that a REMIC
Residual Certificate will have "significant value" for purposes of the above
described rules or that a Residual Owner will receive distributions of amounts
calculated pursuant to those assumptions.
 
    In the case of any REMIC Residual Certificates held by a real estate
investment trust, the aggregate excess inclusions with respect to such REMIC
Residual Certificates, reduced (but not below zero) by the real estate
investment trust taxable income (within the meaning of Code Section 857(b)(2),
excluding any net capital gain), will be allocated among the shareholders of
such trust in proportion to the dividends received by such shareholders from
such trust, and any amount so allocated will be treated as an excess inclusion
with respect to a REMIC Residual Certificate as if held directly by such
shareholder.
 
   5. NONECONOMIC REMIC RESIDUAL CERTIFICATES
 
    Under the REMIC Regulations, transfers of "noneconomic" REMIC Residual
Certificates will be disregarded for all federal income tax purposes if "a
significant purpose of the transfer was to enable the transferor to impede the
assessment or collection of tax". If such transfer is disregarded, the purported
transferor will continue to remain liable for any taxes due with respect to the
income on such "noneconomic" REMIC Residual Certificate. The REMIC Regulations
provide that a REMIC Residual Certificate will be considered a noneconomic
residual interest unless, at the time of its transfer and based on the
Prepayment Assumption and any required or permitted clean up calls or required
liquidation provided for in the REMIC's organizational documents, (1) the
present value of the expected future distributions (discounted using the AFR) on
the REMIC Residual Certificate equals at least the present value of the expected
tax on the anticipated excess inclusions, and (2) the transferor reasonably
expects that the transferee will receive distributions with respect to the REMIC
Residual Certificate at or after the time the taxes accrue on the anticipated
excess inclusions in an amount sufficient to satisfy the accrued taxes.
Accordingly, all transfers of REMIC Residual Certificates that may constitute
noneconomic residual interests will be subject to certain restrictions under the
terms of the related Pooling and Servicing Agreement that are intended to reduce
the possibility of any such transfer being disregarded. Such restrictions will
require each party to a transfer to provide an affidavit that no purpose of such
transfer is to impede the assessment or collection of tax, including certain
representations as to the financial condition of the prospective transferee.
Prior to purchasing a REMIC Residual Certificate, prospective purchasers should
consider the possibility that a purported transfer of such REMIC Residual
Certificate by such a purchaser to another purchaser at some future date may be
disregarded in accordance with the above-described rules, which would result in
the retention of tax liability by such purchaser. The applicable Prospectus
Supplement will disclose whether offered REMIC Residual Certificates may be
considered "noneconomic" residual interests under the REMIC Regulations;
provided, however, that any disclosure that a REMIC Residual Certificate will or
will not be considered "noneconomic" will be based upon certain assumptions, and
the Company will make no representation that a REMIC Residual Certificate will
not be considered "noneconomic" for purposes of the above-described rules or
that a REMIC Residual Owner will receive distributions calculated pursuant to
such assumptions. See "Foreign Investors in REMIC Certificates" below for
additional restrictions applicable to transfers of certain REMIC Residual
Certificates to foreign persons.
 
   6. TAX-EXEMPT INVESTORS
 
    Generally, tax exempt organizations that are not subject to Federal income
taxation on "unrelated business taxable income" pursuant to Code Section 511 are
treated as "disqualified organizations" under provisions of the 1988 Act. Under
provisions of the Pooling Agreement, such organizations generally are prohibited
from owning Residual Certificates. For Residual Owners that are subject to tax
on unrelated business taxable income (as defined in Code Section 511), an excess
inclusion of such Residual Owner is treated as unrelated business taxable
income. See "--Sales of REMIC Certificates".
 
   7. REAL ESTATE INVESTMENT TRUSTS
 
    If the applicable Prospectus Supplement so provides, a Mortgage Pool may
hold Mortgage Loans bearing interest based wholly or partially on Mortgagor
profits, Mortgaged Property appreciation, or
 
                                       72
<PAGE>
similar contingencies. Such interest, if earned directly by a real estate
investment trust ("REIT"), would be subject to the limitations of Code sections
856 (f) and 856 (j). Treasury Regulations treat a REIT holding a REMIC Residual
Certificate for a principal purpose of avoiding such Code provisions as
receiving directly the income of the REMIC Mortgage Pool, hence potentially
jeopardizing its qualification for taxation as a REIT and exposing such income
to taxation as a prohibited transaction at a 100 percent rate.
 
   8. MARK-TO-MARKET RULES
 
    On December 28, 1993, the IRS released temporary regulations (the
"Mark-to-Market Regulations") relating to the requirement that a securities
dealer mark to market securities held for sale to customers. This mark-to-market
requirement applies to all securities owned by a dealer, except to the extent
that the dealer has specifically identified a security as held for investment.
The Mark-to-Market Regulations provide that for purposes of this mark-to-market
requirement, a "negative value" REMIC Residual Certificate is not treated as a
security and thus generally may not be marked to market. This exclusion from the
mark-to-market requirement is expanded to include all REMIC Residual
Certificates under proposed Treasury regulations published January 4, 1995 which
provide that any REMIC Residual Certificate issued after January 4, 1995 will
not be treated as a security and therefore generally may not be marked to
market. Prospective purchasers of a REMIC Residual Certificate should consult
their tax advisors regarding the possible application of the mark-to-market
requirement to REMIC Residual Certificates.
 
  E. SALES OF REMIC CERTIFICATES
 
    If a REMIC Certificate is sold, the seller will recognize gain or loss equal
to the difference between the amount realized on the sale and its adjusted basis
in the REMIC Certificate. The adjusted basis of a REMIC Regular Certificate
generally will equal the cost of such REMIC Regular Certificate to the seller,
increased by any original issue discount or market discount included in the
seller's gross income with respect to such REMIC Regular Certificate and reduced
by premium amortization deductions and distributions previously received by the
seller of amounts included in the stated redemption price at maturity of such
REMIC Regular Certificate. The adjusted basis of a REMIC Residual Certificate
will be determined as described under "--Taxation of Owners of REMIC Residual
Certificates--Basis Rules and Distributions", above. Gain from the disposition
of a REMIC Regular Certificate that might otherwise be treated as a capital gain
will be treated as ordinary income to the extent that such gain does not exceed
the excess, if any, of (i) the amount that would have been includible in such
holder's income had income accrued at a rate equal to 110% of the AFR as of the
date of purchase over (ii) the amount actually includible in such holder's
income. Except as otherwise provided under "--Taxation of Owners of REMIC
Regular Certificates--Market Discount and Premium" and under Code Section
582(c), any additional gain or any loss on the sale or exchange of a REMIC
Certificate will be capital gain or loss, provided such REMIC Certificate is
held as a capital asset (generally, property held for investment) within the
meaning of Code Section 1221. The Code currently provides for a top marginal tax
rate on ordinary income of 39.6% for individuals while maintaining a maximum
marginal rate for the long-term capital gains of individuals at 28%. There is no
such rate differential for corporations. In addition, the distinction between a
capital gain or loss and ordinary income or loss remains relevant for other
purposes, including limitations on the use of capital losses to offset ordinary
income.
 
    A portion of any gain from the sale of a REMIC Regular Certificate that
might otherwise be capital gain may be treated as ordinary income to the extent
that such Certificate is held as part of a "conversion transaction" within the
meaning of Code Section 1258. A conversion transaction generally is one in which
the taxpayer has taken two or more positions in Certificates or similar property
that reduce or eliminate market risk, if substantially all of the taxpayer's
return is attributable to the time value of the taxpayer's net investment in
such transaction. The amount of gain so realized in a conversion transaction
that is recharacterized as ordinary income generally will not exceed the amount
of interest that would have accrued on the taxpayer's net investment at 120% of
the AFR at the time the taxpayer enters into the conversion transaction, subject
to appropriate reduction for prior inclusion of interest and other ordinary
income items from the transaction.
 
                                       73
<PAGE>
    A taxpayer may elect to have net capital gain taxed at ordinary income rates
rather than capital gains rates in order to include such net capital gain in
total net investment income for that taxable year, for purposes of the
limitation on the deduction of interest on indebtedness incurred to purchase or
carry property held for investment to a taxpayer's net investment income.
 
    The recently enacted Omnibus Budget Reconciliation Act of 1993 (the "Budget
Act") revised the rules for deducting interest on indebtedness allocable to
property held for investment. Generally, deductions for such interest are
limited to a taxpayer's net investment income for each taxable year. As amended
by the Budget Act, net investment income for each taxable year includes net
capital gain attributable to the disposition of investment property only if the
taxpayer elects to have such net capital gain taxed at ordinary income rates
rather than capital gains rates.
 
    If a Residual Owner sells a REMIC Residual Certificate at a loss, the loss
will not be recognized if, within six months before or after the sale of the
REMIC Residual Certificate, such Residual Owner purchases another residual
interest in any REMIC or any interest in a taxable mortgage pool (as defined in
Code Section 7701(i)) comparable to a residual interest in a REMIC. Such
disallowed loss will be allowed upon the sale of the other residual interest (or
comparable interest) if the rule referred to in the preceding sentence does not
apply to that sale. While the Committee Report states that this rule may be
modified by Treasury regulations, the REMIC Regulations do not address this
issue and it is not clear whether any such modification will in fact be
implemented or, if implemented, what the precise nature or effective date of it
would be.
 
    The 1988 Act makes transfers of a residual interest to certain "disqualified
organizations" subject to an additional tax on the transferor in an amount equal
to the maximum corporate tax rate applied to the present value of the total
anticipated excess inclusions (discounted using the applicable Federal rate)
with respect to such residual interest for the periods after the transfer. For
this purpose, "disqualified organizations" includes the United States, any state
or political subdivision of a state, any foreign government or international
organization or any agency or instrumentality of any of the foregoing; any
tax-exempt entity (other than a Code Section 521 cooperative) which is not
subject to the tax on unrelated business income; and any rural electrical and
telephone cooperative. The anticipated excess inclusions must be determined as
of the date that the REMIC Residual Certificate is transferred and must be based
on events that have occurred up to the time of such transfer, the Prepayment
Assumption, and any required or permitted clean up calls or required liquidation
provided for in the REMIC's organizational documents. The tax generally is
imposed on the transferor of the REMIC Residual Certificate, except that it is
imposed on an agent for a disqualified organization if the transfer occurs
through such agent. The Pooling and Servicing Agreement requires, as a
prerequisite to any transfer of a Residual Certificate, the delivery to the
Trustee of an affidavit of the transferee to the effect that it is not a
disqualified organization and contains other provisions designed to render any
attempted transfer of a Residual Certificate to a disqualified organization
void.
 
    In addition, if a "pass-through entity" includes in income excess inclusions
with respect to a REMIC Residual Certificate, and a disqualified organization is
the record holder of an interest in such entity, then a tax will be imposed on
such entity equal to the product of (i) the amount of excess inclusions on the
REMIC Residual Certificate that are allocable to the interest in the
pass-through entity held by such disqualified organization and (ii) the highest
marginal federal income tax rate imposed on corporations. A pass-through entity
will not be subject to this tax for any period, however, if the record holder of
an interest in such entity furnishes to such entity (i) such holder's social
security number and a statement under penalties of perjury that such social
security number is that of the record holder or (ii) a statement under
penalities of perjury that such record holder is not a disqualified
organization. For these purposes, a "pass-through entity" means any regulated
investment company, real estate investment trust, trust, partnership or certain
other entities described in Section 860E(e)(6) of the Code. In addition, a
person holding an interest in a pass-through entity as a nominee for another
person shall, with respect to such interest, be treated as a pass-through
entity. Legislation presently pending before the United States Congress, the Tax
Simplification and Technical Corrections Bill of 1993 (the "Simplification
Act"), would apply this tax on an annual basis to "large partnerships".
Generally, the Simplification Act would treat partnerships that have, or have
had, 250 or more partners as a large partnership for this purpose. The
 
                                       74
<PAGE>
Simplification Act would not limit application of the tax to excess inclusions
allocable to disqualified organizations, and in fact would apply the tax to
large partnerships having no disqualified organizations as partners. If enacted
in its present form, the Simplification Act would apply to partnership taxable
years ending on or after December 31, 1994.
 
  F. PASS-THROUGH OF SERVICING FEES
 
    The general rule is that Residual Certificateholders take into account
taxable income or net loss of the related REMIC Mortgage Pool. Under that rule,
servicing compensation of the Company and the subservicers (if any) would be
allocated to the holders of the REMIC Residual Certificates, and therefore would
not affect the income or deductions of holders of REMIC Regular Certificates.
However, in the case of a "single-class REMIC", such expenses and an equivalent
amount of additional gross income will be allocated among all holders of REMIC
Regular Certificates and REMIC Residual Certificates for purposes of the
limitations on the deductibility of certain miscellaneous itemized deductions by
individuals contained in Code Sections 56(b)(1) and 67. Generally, any holder of
a REMIC Certificate who is an individual, estate or trust will be able to deduct
such expenses in determining regular tax liability only to the extent that such
expenses together with certain other miscellaneous itemized deductions of such
individual, estate or trust exceed 2% of adjusted gross income; such a holder
may not deduct such expenses to any extent in determining liability for
alternative minimum tax. Accordingly, REMIC Residual Certificates, and REMIC
Regular Certificates receiving an allocation of servicing compensation, may not
be appropriate investments for individuals, estates or trusts, and such persons
should carefully consult with their own tax advisors regarding the advisability
of an investment in such Certificates.
 
    A "single-class REMIC" is a REMIC that either (i) would be treated as a
pass-through trust under the provisions of Treasury Regulation Section
301.7701-4(c) in the absence of a REMIC election, or (ii) is substantially
similar to such a pass-through trust and is structured with the principal
purpose of avoiding the allocation of investment expenses to holders of REMIC
Regular Certificates. Unless otherwise stated in the related Prospectus
Supplement, the Company intends to treat a REMIC Mortgage Pool as other than a
"single-class REMIC", consequently allocating servicing compensation expenses
and related income amounts entirely to REMIC Residual Certificates and in no
part to REMIC Regular Certificates.
 
  G. PROHIBITED TRANSACTIONS AND OTHER POSSIBLE REMIC TAXES
 
    The Code imposes a tax on REMIC Mortgage Pools equal to 100 percent of the
net income derived from "prohibited transactions". In general, a prohibited
transaction means the disposition of a Mortgage Loan other than pursuant to
certain specified exceptions, the receipt of income from a source other than a
Mortgage Loan or certain other permitted investments, the receipt of
compensation for services, or gain from the disposition of an asset purchased
with the payments on the Mortgage Loans for temporary investment pending
distribution on the REMIC Certificates. The Code also imposes a 100 percent tax
on the value of any contribution of assets to the REMIC after the "start-up day"
(the day on which the regular and residual interests are issued), other than
pursuant to specified exceptions, and subjects "net income from foreclosure
property" to tax at the highest corporate rate. It is not anticipated that a
REMIC Mortgage Pool will engage in any such transactions or receive any such
income.
 
  H. TERMINATION OF A REMIC TRUST FUND
 
    In general, no special tax consequences will apply to a holder of a REMIC
Regular Certificate upon the termination of the REMIC Mortgage Pool by virtue of
the final payment or liquidation of the last Mortgage Loan remaining in the
REMIC Mortgage Pool. If a Residual Owner's adjusted basis in its REMIC Residual
Certificate at the time such termination occurs exceeds the amount of cash
distributed to such Residual Owner in liquidation of its interest, then,
although the matter is not entirely free from doubt, it appears that the
Residual Owner would be entitled to a loss (which would be a capital loss) equal
to the amount of such excess.
 
  I. REPORTING AND OTHER ADMINISTRATIVE MATTERS OF REMICS
 
    Reporting of interest income, including any original issue discount, with
respect to REMIC Regular Certificates is required annually, and may be required
more frequently under Treasury
 
                                       75
<PAGE>
regulations. In addition to those holders of REMIC Regular Certificates to whom
information reporting generally applies, certain holders of REMIC Regular
Certificates who are generally exempt from information reporting on debt
instruments, such as corporations, banks, registered securities or commodities
brokers, real estate investment trusts, registered investment companies, common
trust funds, charitable remainder annuity trusts and unitrusts, will be provided
interest and original issue discount income information and the information set
forth in the following paragraph upon request in accordance with the
requirements of the Treasury regulations. The information must be provided by
the later of 30 days after the end of the quarter for which the information was
requested, or two weeks after the receipt of the request. The REMIC Mortgage
Pool must also comply with rules requiring the face of a REMIC Certificate
issued at more than a DE MINIMIS discount to disclose the amount of original
issue discount and the issue date and requiring such information to be reported
to the Treasury Department.
 
    The REMIC Regular Certificate information reports must include a statement
of the "adjusted issue price" of the REMIC Regular Certificate at the beginning
of each accrual period. In addition, the reports must include information
necessary to compute the accrual of any market discount that may arise upon
secondary trading of REMIC Regular Certificates. Because exact computation of
the accrual of market discount on a constant yield method would require
information relating to the holder's purchase price which the REMIC Mortgage
Pool may not have, it appears that this provision will only require information
pertaining to the appropriate proportionate method of accruing market discount.
 
    The responsibility for complying with the foregoing reporting rules will be
borne by the Company.
 
    For purposes of the administrative provisions of the Code, REMIC Mortgage
Pools will be treated as partnerships and the holders of Residual Certificates
will be treated as partners. Unless otherwise stated in the applicable
Prospectus Supplement, the Company will file federal income tax information
returns on behalf of the related REMIC Mortgage Pool, and will be designated as
agent for, and will act on behalf of the "tax matters person" with respect to
the REMIC Mortgage Pool in all respects.
 
    As agent for the tax matters person, the Company will, subject to certain
notice requirements and various restrictions and limitations, generally have the
authority to act on behalf of the REMIC and the Residual Owners in connection
with the administrative and judicial review of items of income, deduction, gain
or loss of the REMIC Mortgage Pool, as well as the REMIC Mortgage Pool's
classification. Residual Owners will generally be required to report such REMIC
Mortgage Pool items consistently with their treatment on the REMIC Mortgage
Pool's federal income tax information return and may in some circumstances be
bound by a settlement agreement between the Master Servicer, as agent for the
tax matters person, and the IRS concerning any such REMIC Mortgage Pool item.
Adjustments made to the REMIC Mortgage Pool tax return may require a Residual
Owner to make corresponding adjustments on its return, and an audit of the REMIC
Mortgage Pool's tax return, or the adjustments resulting from such an audit,
could result in an audit of a Residual Owner's return.
 
  J. BACKUP WITHHOLDING WITH RESPECT TO REMIC CERTIFICATES
 
    Payments of interest and principal on REMIC Regular Certificates, as well as
payments of proceeds from the sale of REMIC Certificates, may be subject to the
"backup withholding tax" under Section 3406 of the Code at a rate of 31 percent
if recipients of such payments fail to furnish to the payor certain information,
including their taxpayer identification numbers, or otherwise fail to establish
an exemption from such tax. Any amounts deducted and withheld from a
distribution to a recipient would be allowed as a credit against such
recipient's federal income tax. Furthermore, certain penalties may be imposed by
the IRS on a recipient of payments that is required to supply information but
that does not do so in the proper manner.
 
  K. FOREIGN INVESTORS IN REMIC CERTIFICATES
 
   1. REMIC REGULAR CERTIFICATES
 
    Except as qualified below, payments made on a REMIC Regular Certificate to a
REMIC Regular Certificateholder that is not a U.S. Person, as hereinafter
defined (a "Non-U.S. Person"), or to a
 
                                       76
<PAGE>
person acting on behalf of such a Certificateholder, generally will be exempt
from U.S. federal income and withholding taxes, provided (a) the holder of the
Certificate is not subject to U.S. tax as a result of a connection to the United
States other than ownership of such Certificate, (b) the holder of such
Certificate signs a statement under penalties of perjury that certifies that
such holder is a Non-U.S. Person, and provides the name and address of such
holder, and (c) the last U.S. Person in the chain of payment to the holder
received such statement from such holder or a financial institution holding on
its behalf and does not have actual knowledge that such statement is false. If
the holder does not qualify for exemption, distributions of interest, including
distributions in respect of accrued original issue discount, to such holder may
be subject to a withholding tax rate of 30 percent, subject to reduction under
any applicable tax treaty.
 
    "U.S. Person" means a citizen or resident of the United States, a
corporation, partnership or other entity created or organized in or under the
laws of the United States or any political subdivision thereof, or an estate or
trust that is subject to U.S. federal income tax regardless of the source of its
income.
 
    Holders of REMIC Regular Certificates should be aware that the IRS might
take the position that exemption from U.S. withholding taxes does not apply to
such a holder that also directly or indirectly owns 10 percent or more of the
REMIC Residual Certificates of a particular Series of Certificates. Further, the
foregoing rules will not apply to exempt a United States shareholder of a
controlled foreign corporation from taxation on such United States shareholder's
allocable portion of the interest or original issue discount income earned by
such controlled foreign corporation.
 
   2. REMIC RESIDUAL CERTIFICATES
 
    Amounts paid to a Residual Owner that is a Non-U.S. Person generally will be
treated as interest for purposes of applying the withholding tax on Non-U.S.
Persons with respect to income on its REMIC Residual Certificate. However, it is
unclear whether distributions on REMIC Residual Certificates will be eligible
for the general exemption from withholding tax that applies to REMIC Regular
Certificates as described above. Treasury regulations provide that, for purposes
of the portfolio interest exception, payments to the foreign owner of a REMIC
Residual Certificate are to be considered paid on the obligations held by the
REMIC, rather than on the Certificate itself. Such payments would thus only
qualify for the portfolio interest exception if the underlying obligations held
by the REMIC would so qualify. Such withholding tax generally would be imposed
at a rate of 30 percent but would be subject to reduction under any tax treaty
applicable to the Residual Owner. However, there is no exemption from
withholding tax nor may the rate of such tax be reduced, under a tax treaty or
otherwise, with respect to any distribution of income that is an excess
inclusion. See "--Taxation of Owners of REMIC Residual Certificates--Excess
Inclusions".
 
    Certain restrictions relating to transfers of REMIC Residual Certificates to
and by investors who are not U.S. Persons are also imposed by the REMIC
Regulations. First, transfers of REMIC Residual Certificates to Non-U.S. Persons
that have "tax avoidance potential" are disregarded for all federal income tax
purposes. If such transfer is disregarded, the purported transferor of such a
REMIC Residual Certificate to a Non-U.S. Person would continue to remain liable
for any taxes due with respect to the income on such REMIC Residual Certificate.
A REMIC Residual Certificate has tax avoidance potential unless, at the time of
the transfer, the transferor reasonably expects that the REMIC will distribute
to the transferee amounts that will equal at least 30 percent of each excess
inclusion, and that such amounts will be distributed at or after the time at
which the excess inclusion accrues and not later than the close of the calendar
year following the calendar year of accrual. This rule does not apply to
transfers if the income from the REMIC Residual Certificate is taxed in the
hands of the transferee as income effectively connected with the conduct of a
U.S. trade or business. Second, if a Non-U.S. Person transfers a REMIC Residual
Certificate to a U.S. Person, and the transfer has the effect of allowing the
transferor to avoid tax on accrued excess inclusions, that transfer is
disregarded for all federal income tax purposes and the purported Non-U.S.
Person transferor continues to be treated as the owner of the REMIC Residual
Certificate. Thus, the REMIC's liability to withhold 30 percent of the accrued
excess inclusions is not terminated even though the REMIC Residual Certificate
is no longer held by a Non-U.S. Person.
 
                                       77
<PAGE>
  L. STATE AND LOCAL TAXATION
 
    Many states do not automatically conform to changes in the federal income
tax laws. Consequently, a REMIC Mortgage Pool which would not qualify as a fixed
investment trust for federal income tax purposes may be characterized as a
corporation, a partnership, or some other entity for purposes of state income
tax law. Such characterization could result in entity level income or franchise
taxation of a REMIC Mortgage Pool formed in, owning mortgages or property in, or
having servicing activity performed in a state without conforming REMIC
provisions in its income or franchise tax law. Further, REMIC Regular
Certificateholders resident in nonconforming states may have their ownership of
REMIC Regular Certificates characterized as an interest other than debt of the
REMIC such as stock or a partnership interest. Investors are advised to consult
their tax advisors concerning the state and local income tax consequences of
their purchase and ownership of REMIC Regular Certificates.
 
                            METHODS OF DISTRIBUTION
 
    Certificates are being offered hereby in Series from time to time (each
Series evidencing a separate Mortgage Pool) through any of the following
methods:
 
        1.  By negotiated firm commitment underwriting and public reoffering by
    underwriters;
 
        2.  By agency placements through one or more placement agents primarily
    with institutional investors and dealers; and
 
        3.  By placement directly by the Company with institutional investors.
 
    A Prospectus Supplement will be prepared for each Series which will describe
the method of offering being used for that Series and will set forth the
identity of any underwriters thereof and either the price at which such Series
is being offered, the nature and amount of any underwriting discounts or
additional compensation to such underwriters and the proceeds of the offering to
the Company, or the method by which the price at which the underwriters will
sell the Certificates will be determined. Each Prospectus Supplement for an
underwritten offering will also contain information regarding the nature of the
underwriters' obligations, any material relationship between the Company and any
underwriter and, where appropriate, information regarding any discounts or
concessions to be allowed or reallowed to dealers or others and any arrangements
to stabilize the market for the Certificates so offered. In firm commitment
underwritten offerings, the underwriters will be obligated to purchase all of
the Certificates of such Series if any such Certificates are purchased.
Certificates may be acquired by the underwriters for their own accounts and may
be resold from time to time in one or more transactions, including negotiated
transactions, at a fixed public offering price or at varying prices determined
at the time of sale.
 
    Underwriters and agents may be entitled under agreements entered into with
the Company to indemnification by the Company against certain civil liabilities,
including liabilities under the Securities Act of 1933, as amended (the "Act"),
or to contribution with respect to payments which such underwriters or agents
may be required to make in respect thereof.
 
    If a Series is offered other than through underwriters, the Prospectus
Supplement relating thereto will contain information regarding the nature of
such offering and any agreements to be entered into between the Company and
purchasers of Certificates of such Series.
 
                        TRANSFERABILITY OF CERTIFICATES
 
    The Company anticipates that the Certificates will be sold primarily to
institutional investors. Purchasers of Certificates, including dealers, may,
depending on the facts and circumstances of such purchases, be deemed to be
"underwriters" within the meaning of the Act, in connection with reoffers and
sales by them of Certificates. Certain purchasers will be required to give the
Company prior notice of their intention to resell their Certificates, and to
represent to the Company that they will observe certain prospectus delivery and
anti-manipulative requirements of the Act and the Securities Exchange Act of
1934, as amended. The Company will charge any Certificateholder requesting
amended or updated Prospectuses or Prospectus Supplements all expenses incurred
by the Company for preparation and delivery of such documents.
Certificateholders should consult with their legal advisors in this regard prior
to any such reoffer or resale.
 
                                       78
<PAGE>
                                 LEGAL MATTERS
 
    Certain legal matters will be passed upon for the Company by Thomas G.
Lehmann, General Counsel, Vice President and Secretary of the Company, and by
its special counsel, Orrick, Herrington & Sutcliffe, San Francisco, California.
 
                             FINANCIAL INFORMATION
 
    The Company has determined that its financial statements are not material to
the offering made hereby. However, any prospective investor who desires to
review financial information concerning the Company will be provided, upon
request, with a copy of the consolidated balance sheet of the Company as of
December 31, 1994 or the end of its last fiscal year, whichever is later, and a
copy of the most recent statement of earnings of the Company. Such requests
should be directed to PNC Mortgage Securities Corp., Controller's Department, 75
North Fairway Drive, Vernon Hills, Illinois 60061.
 
                             ADDITIONAL INFORMATION
 
    This Prospectus, together with the Prospectus Supplement for each Series of
Certificates, contains a summary of the material terms of the applicable
exhibits to the Registration Statement and the documents referred to herein and
therein. Copies of such exhibits are on file at the offices of the Securities
and Exchange Commission in Washington, D.C., may be obtained at rates prescribed
by the Commission upon request to the Commission and may be inspected, without
charge, at the Commission's offices.
 
                                       79
<PAGE>
                                    GLOSSARY
 
    Set forth below is a list of certain of the more significant terms used in
this Prospectus and the pages on which the definitions of such terms may be
found.
<TABLE>
<CAPTION>
                                                    PAGE
                                                    -----
<S>                                              <C>
Act............................................          66
Advance Claims Endorsement.....................          39
Advances.......................................          11
AFR............................................          59
Agency Certificates............................           6
Bankruptcy Bond................................           6
Bankruptcy Instrument..........................          38
Bankruptcy Loss................................          37
Basic Prepayment Assumption....................          15
BPA............................................          15
Buydown Fund...................................          10
Buydown Loans..................................           5
CERCLA.........................................          48
Certificate Account............................          24
Certificate Administrator......................           4
Certificate Administrator Fee..................          11
Certificates...................................           1
Class..........................................           1
Code...........................................          33
Commission.....................................          11
Company........................................           1
Compensating Interest..........................          14
Conversion Fee.................................          12
Cooperative....................................          10
Cooperative Loan...............................           1
Cooperative Note...............................          10
Curtailment....................................          14
Custodial Account for P&I......................          22
Cut-Off Date...................................           7
Defaulted Mortgage Loss........................          37
Determination Date.............................          26
Distribution Date..............................           4
Distribution Period............................          25
DOL............................................          49
Eligible Investments...........................          24
ERISA..........................................           7
Extraordinary Losses...........................          38
FDIC...........................................          15
FHA............................................          10
FHA Approved Mortgagees........................          15
FHA Insurance Policies.........................          10
FHLMC..........................................           6
FHLMC Approved Mortgagees......................          15
FNMA...........................................           6
FNMA Approved Mortgagees.......................          15
Fraud Bond.....................................           5
Fraud Instrument...............................          38
Fraud Loss.....................................          37
Garn-St. Germain Act...........................          47
GNMA...........................................           6
Indemnified Parties............................          31
Insurance Proceeds.............................          22
Investment Account.............................          23
Investment Period..............................          23
IRS............................................          53
Lenders........................................          15
Letter of Credit...............................           6
Letter of Credit Bank..........................          42
 
<CAPTION>
                                                    PAGE
                                                    -----
<S>                                              <C>
Liquidation Proceeds...........................          22
Loss...........................................          34
Master Servicer................................           4
Master Servicing Fee...........................          11
Mortgaged Properties...........................           9
Mortgage Loans.................................           1
Mortgage Notes.................................           9
Mortgage Pool..................................           1
Mortgage Pool Insurance Policy.................           5
Mortgages......................................           9
Mortgagor......................................           6
Net Rate.......................................          21
1988 Act.......................................          59
Non-U.S. Person................................          64
OID Regulations................................          51
Parties in Interest............................          49
Paying Agent...................................          18
Payoff.........................................          14
Plans..........................................          49
Pooling Agreement..............................          11
Prepayment Assumption..........................          53
Primary Insurance Policy.......................           5
Principal Prepayment...........................          15
Private Certificates...........................           6
PTCE 83-1......................................          49
Record Date....................................          19
Regulation.....................................          49
Relief Act.....................................          47
REMIC..........................................           1
REMIC Certificates.............................          51
REMIC Mortgage Pool............................          51
REMIC Provisions...............................          51
REMIC Regulations..............................          51
Remittance Rate................................           1
Reserve Account................................          40
Reserve Fund...................................           6
Residual Owner.................................          58
Retained Yield.................................          22
Sellers........................................           4
Seller/Servicers...............................           4
Selling and Servicing Contracts................          18
Senior Certificates............................          39
Series.........................................           1
Servicer.......................................           4
Servicing Contracts............................          11
Servicing Fee..................................          11
Special Hazard Instrument......................          38
Special Hazard Insurance Policy................           6
Special Hazard Loss............................          37
Title V........................................          47
Title VIII.....................................          48
Trustee........................................          11
Trust Fund.....................................           1
UCC............................................          55
VA.............................................          10
VA Guaranties..................................          10
VA Loans.......................................          10
Withdrawal Date................................          23
</TABLE>
 
                                       80
<PAGE>
 
                                             -----------------------------------
 
                                             -----------------------------------
 
                                                     PNC MORTGAGE
                                                   SECURITIES CORP.
                                                 DEPOSITOR AND MASTER SERVICER
 
                                                          MORTGAGE
                                                 PASS-THROUGH CERTIFICATES
                                                       SERIES 1997-3
 
                                                        $446,638,440
                                                         (APPROXIMATE)
 
              ------------------------------------------------------------------
 
                                                     PROSPECTUS SUPPLEMENT
 
                ----------------------------------------------------------------
 
                                                DONALDSON, LUFKIN & JENRETTE
                                                    SECURITIES CORPORATION
 
                                                        APRIL 28, 1997
 
                                     -------------------------------------------
                                     -------------------------------------------


© 2022 IncJournal is not affiliated with or endorsed by the U.S. Securities and Exchange Commission