ZITEL CORP
8-K, 1999-02-16
PATENT OWNERS & LESSORS
Previous: AIM ADVISOR FUNDS INC, 485APOS, 1999-02-16
Next: ZITEL CORP, 10-Q/A, 1999-02-16



<PAGE>

                         SECURITIES EXCHANGE AND COMMISSION

                              WASHINGTON, D. C.  20549

                                      FORM 8-K

                                   CURRENT REPORT

                      Pursuant to Section 13 or 15(d) of the
                          Securities Exchange Act of 1934

        Date of Report (Date of earliest event reported):  February 3, 1999

                                 ZITEL CORPORATION
               (Exact name of registrant as specified in its charter)

                                     CALIFORNIA
                   (State or other jurisdiction of incorporation)

                 0-12194                               94-2566313
          (Commission File No.)            (IRS Employer Identification No.)


                               47211 BAYSIDE PARKWAY,
                           FREMONT, CALIFORNIA 94538-6517
               (Address of principal executive offices and zip code)

         Registrant's telephone number, including area code: (510) 440-9600

<PAGE>

ITEM 5.   OTHER EVENTS

     A.   PLACEMENT OF DEBENTURES

     On February 3, 1999, Zitel Corporation (the "Company") completed the 
private placement of $5,000,000 in principal amount of 3% Convertible 
Subordinated Debentures due February 2, 2000 (the "Debentures") and five year 
Common Stock Purchase Warrants covering 75,000 shares of the Company's Common 
Stock (the "Common Stock") to a small number of institutional investors in a 
transaction exempt from the registration requirements of the Securities Act 
of 1933, as amended (the "Securities Act").  The Debentures are convertible 
into the number of shares of Common Stock equal to the amount of principal 
and accrued interest being converted divided by the Conversion Price.  The 
Conversion Price will be equal to 90% of the average closing bid prices of 
the Common Stock for each of the ten trading days immediately following, but 
not including the February 3, 1999 closing date of the placement.  There may 
be an adjustment to the Conversion Price in the event that the lesser of 90% 
of the average of the closing bid prices of the Common Stock for the twenty 
consecutive trading days preceding but not including: (a) the 60 calendar day 
anniversary of the closing date; or (b) the 45 calendar day anniversary of 
the effective date of a registration statement under the Securities Act 
registering the resale of the shares of Common Stock issuable upon conversion 
of the Debentures and exercise of the Warrants is less than the Conversion 
Price, then that lesser price so calculated shall thereafter be the 
Conversion Price; there may be an interim adjustment of the Conversion Price 
on the earlier to occur of the dates specified in clauses (a) and (b) above.  
The Conversion Price and number of shares subject to the Debentures and 
Warrants are subject to adjustment in the event of certain reorganizations 
and distributions by the Company and to formula antidilution protection upon 
certain sales of Common Stock or Common Stock equivalents at prices less than 
the Conversion Price or then the current market of the Common Stock.  The 
Debentures also provide for certain additional rights in the event that, 
prior to the later of the 45 day anniversary of the closing date or the 
effective date of a registration statement, the closing bid price of the 
Common Stock for five consecutive trading days is less than 50% of 111.11% of 
the original Conversion Price.  The exercise price of the Warrants is equal 
to 130% of the Conversion Price.

     All Debentures outstanding on February 2, 2000 will convert 
automatically, provided certain conditions specified in the Debentures are 
satisfied.  The holders of the Debentures have registration rights with 
respect to the Common Stock as set forth in a Registration Rights Agreement 
pursuant to which the Company has agreed to register for resale under the 
Securities Act the Common Stock issuable upon conversion of the Debentures, 
on or before March 5, 1999.

     The foregoing description does not purport to be complete and is 
qualified by reference to the definitive agreements filed as Exhibits 
herewith.

ITEM 7.   EXHIBITS

     (c)  The following exhibits are furnished in accordance with the 
provisions of Item 601 of Regulation S-K:

<TABLE>
<CAPTION>
Exhibit Number           Exhibit
<S>                      <C>
                                     2
<PAGE>

               4.1       Form of Convertible Subordinated Debenture

               4.2       Form of Common Stock Purchase Warrant

               4.3       Registration Rights Agreement

               4.4       Securities Purchase Agreement

               4.5       Placement Agency Agreement
</TABLE>

     The foregoing is a partial summary of certain terms of the Debentures 
and Warrants and the rights of the holders. Reference is made to the Exhibits 
filed with this report for the actual terms of the Debentures, Warrants and 
such rights.


                                     SIGNATURE

     Pursuant to the requirements of the Securities Exchange Act of 1934, the 
registrant has duly caused this report to be signed on its behalf by the 
undersigned, thereunto duly authorized.

                                          ZITEL CORPORATION

Dated:  February 16, 1999                 By: Henry C. Harris
                                             ----------------------------------
                                              Henry C. Harris
                                              Chief Financial Officer

                                     3
<PAGE>

                                   EXHIBIT INDEX

<TABLE>
<CAPTION>
EXHIBIT
NUMBER    DESCRIPTION
- ------    -----------
<S>       <C>
4.1       Form of Convertible Subordinated Debenture

4.2       Form of Common Stock Purchase Warrant

4.3       Registration Rights Agreement

4.4       Securities Purchase Agreement

4.5       Placement Agency Agreement
</TABLE>

                                     4

<PAGE>

                                    EXHIBIT 4.1

THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS 
AMENDED, OR ANY STATE SECURITIES LAWS.  IT MAY NOT BE SOLD OR OFFERED FOR 
SALE EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER SAID ACT 
AND ANY APPLICABLE STATE SECURITIES LAW OR AN APPLICABLE EXEMPTION FROM SUCH 
REGISTRATION REQUIREMENTS.

NO. ____                                                          $___________

                                 ZITEL CORPORATION

             3% CONVERTIBLE SUBORDINATED DEBENTURE DUE FEBRUARY 1, 2000

     THIS DEBENTURE ("Debenture") is one of a duly authorized issue of 
Debentures of ZITEL CORPORATION, a corporation duly organized and existing 
under the laws of the State of California (the "Company"), designated as the 
Company's 3% Convertible Subordinated Debentures Due February 1, 2000, in an 
aggregate principal amount not exceeding FIVE MILLION U.S. DOLLARS 
(U.S.$5,000,000) (the "Debenture").

     FOR VALUE RECEIVED, the Company promises to pay to ____________________, 
the initial holder hereof, or its order (including successors-in-interest, 
the "Holder"), the principal sum of ____________________________________ 
____________ U.S. DOLLARS (U.S. $___________) on February 1, 2000 (the 
"Maturity Date") in the manner and amount and subject to the terms and 
conditions of Section 6 hereof and to pay interest on the principal sum 
outstanding under this Debenture ("Outstanding Principal Amount"), at the 
rate of 3% per annum due and payable quarterly in arrears on the first day of 
September, December, March and June of each year (each an "Interest Payment 
Date"), with the first such payment due on March 1, 1999.  Interest shall 
accrue daily and compound quarterly commencing on the date hereof and shall 
continue until payment in full of all amounts due under this Debenture.  The 
interest so payable will be paid to the person in whose name this Debenture 
is registered on the records of the Company regarding registration and 
transfers of the Debenture (the "Debenture Register"). Capitalized terms used 
herein and not otherwise defined shall have the meanings set forth in the 
Convertible Subordinated Debenture Purchase Agreement dated as of February 2, 
1999 between the Company and the Holder and the other parties thereto (the 
"Purchase Agreement") or the Registration Rights Agreement dated as of 
February 2, 1999 between the Company and the Holder and the other parties 
thereto (the "Registration Rights Agreement").

     The principal of, and default payments (referred to below) in respect of,
this Debenture are payable in such coin or currency of the United States as of
the time of payment is legal tender for payment of public and private debts, at
the address last appearing on the Debenture Register of the Company as
designated in writing by the Holder hereof from time to time.  The interest on
this Debenture is payable in registered Common Stock of the Company, with the
number of shares of Common Stock determined by dividing (x) the amount of
interest due for such payment period by (y) the Conversion Price determined as
if the Interest Payment Date were a Holder Conversion Date ("Common Stock
Interest"); PROVIDED, HOWEVER, that if such stock is not subject 

                                     1
<PAGE>

to Effective Registration, such interest shall be payable in such coin or 
currency of the United States as of the time of payment is legal tender for 
payment of public and private debts.  If neither the Common Stock Interest 
due hereunder is delivered, nor the cash interest paid, to the Holder as 
provided above, the Holder may choose to add such amounts to the Outstanding 
Principal Amount.  Any Common Stock Interest or cash interest when so added 
to the Outstanding Principal Amount due under this Debenture shall, for all 
purposes of this Debenture, be deemed to have been part of the principal 
indebtedness originally evidenced by this Debenture including, without 
limitation, for purposes of determining interest payable hereunder after the 
applicable Interest Payment Date for which such Common Stock Interest was not 
delivered, or cash interest was not paid, by the Company and amounts 
convertible into Common Shares hereunder after such applicable Interest 
Payment Date.

     The Company will pay any principal due and all accrued and unpaid 
interest due upon this Debenture to the person that is the Holder of this 
Debenture on the records of the Company as of the applicable Interest Payment 
Date and addressed to such Holder at the last address appearing on the 
Debenture Register.

     The Outstanding Principal Amount and interest due hereunder shall bear 
interest, from and after the 31st day following the occurrence and during the 
continuance of an Event of Default hereunder, at the rate equal to the lower 
of the Citibank Prime Rate per annum plus 7% or the highest rate permitted by 
law.

     Additional cash payments (referred to as "default payments") may be 
required pursuant to the Registration Rights Agreement if there occurs an 
"Interfering Event" (as defined therein).  Such default payments, if not paid 
in cash when due, may be treated by the Holder in its sole discretion as 
being added to the Outstanding Principal Amount due under this Debenture.

     Subject to applicable law, any interest otherwise payable that is not 
paid for any applicable period because it would exceed the highest rate 
permitted by law shall become payable whenever the payment thereof, together 
with other interest due for any such subsequent period would not exceed such 
highest legal rate.

     The Holder of this Debenture is entitled to certain rights and remedies 
pursuant to the Purchase Agreement and Registration Rights Agreement, 
including without limitation provisions requiring mandatory redemption of the 
Debenture. This Debenture does not provide voting rights to the Holder.

     This Debenture is subject to the following additional provisions:

     1.   DENOMINATION.  The Debentures are exchangeable for an equal 
aggregate principal amount of Debentures of different denominations, as 
requested by the Holder surrendering the same.  No service charge will be 
made for such registration or transfer or exchange.

     2.   TRANSFERS.  This Debenture may be transferred or exchanged in the
United States only in compliance with the Securities Act of 1933, as amended
(the "Act") and applicable state securities laws, or applicable exemptions
therefrom.  Prior to due presentment for transfer of this Debenture, the Company
may treat the person in whose name this Debenture is duly registered 

                                     2
<PAGE>

on the Company's Debenture Register as the owner hereof for the purpose of 
receiving payment as herein provided, whether or not this Debenture is 
overdue.

     3.   DEFINITIONS.  For purposes hereof the following definitions shall
apply:

          "CHANGE IN CONTROL TRANSACTION" shall mean the occurrence of (x) 
any consolidation or merger of the Company with or into any other corporation 
or other entity or person (whether or not the Company is the surviving 
corporation), or any other corporate reorganization or transaction or series 
of related transactions in which in excess of 50% of the Company's voting 
power is transferred through a merger, consolidation, tender offer or similar 
transaction, or (y) any person (as defined in Section 13(d) of the Securities 
Exchange Act of 1934, as amended (the "Exchange Act")), together with its 
affiliates and associates (as such terms are defined in Rule 405 under the 
Securities Act of 1933, as amended (the "Act")), beneficially owns or is 
deemed to beneficially own (as described in Rule 13d-3 under the Exchange Act 
without regard to the 60-day exercise period) in excess of 50% of the 
Company's voting power.

          "CLOSING BID PRICE" shall mean the last closing bid price on the 
principal Approved Market (as defined in the Purchase Agreement) as reported 
by Bloomberg Financial Market or an equivalent reliable reporting service 
selected by the Holder and the Company.

          "CLOSING DATE" shall mean the date of original issuance of this 
Debenture.

          "COMMON STOCK" shall mean the common stock, no par value, of the 
Company.

          "CONVERSION NOTICE" shall have the meaning set forth in Paragraph 
5(g).

          "CONVERSION PRICE" shall have the meaning set forth in Paragraph 
5(c).

          "CONVERSION RATE" shall have the meaning set forth in Paragraph 
5(b).

          "FORCED CONVERSION DATE" shall mean the Maturity Date, without 
taking into consideration any acceleration thereof by reason of default, 
required redemption, or otherwise.  The Forced Conversion Date shall be 
subject to deferral as provided for herein and in the Registration Rights 
Agreement.

          "HOLDER CONVERSION DATE" shall have the meaning set forth in 
Paragraph 5(g).

          "MARKET PRICE FOR SHARES OF COMMON STOCK" shall mean the price of 
one share of Common Stock determined as follows:

               (i)   If the Common Stock is listed on an Approved Market, the 
Closing Bid Price;

               (ii)  If (i) does not apply but the Common Stock is quoted in 
the over-the-counter market, another recognized exchange, on the pink sheets 
or bulletin board, the lesser of (A) the lowest sales price or (B) the mean 
between the last reported "bid" and "asked" prices thereof on the date of 
valuation; and

                                     3
<PAGE>

               (iii) If neither clause (i) nor (ii) above applies, the market 
value as determined by a nationally recognized investment banking firm or 
other nationally recognized financial advisor retained by the Company for 
such purpose, taking into consideration, among other factors, the earnings 
history, book value and prospects for the Company, and the prices at which 
shares of Common Stock recently have been traded.  Such determination shall 
be conclusive and binding on all persons.

          "MATRIDIGM TRANSACTION" shall mean any transaction or series of 
transactions whereby the Company acquires debt or equity securities of 
Matridigm Corporation, a California corporation, or the business of the 
Company and Matridigm are combined, and shall include, without limitation, 
the issuance for cash of shares of the Common Stock of the Company with a 
fair market value not to exceed $2,000,000, as determined as of the purchase 
date and pursuant to one-time reset provisions agreed to between the Company 
and the purchasers, with the proceeds used to procure the release of 
obligations of the purchasers to guarantee obligations of Matridigm.

          "TRADING DAY" shall mean a day on which the Common Stock is traded 
on the NASDAQ or principal exchange on which the Common Stock has been listed 
(or any similar organization or agency succeeding such market or exchange's 
functions of reporting prices).

     4.   CHANGE IN CONTROL, ETC.  If a Change in Control Transaction occurs 
before 30 days have elapsed after the date that the Registrable Securities 
(as defined in the Registration Rights Agreement) have been registered as 
contemplated therein (the "Effectiveness Date") (such 30 days to be extended 
one (1) day for each day after such date on which there is a lack of 
Effective Registration), or if the provisions of Section 7 have not been 
complied with, then the Holder shall be entitled to have the Company redeem 
this Debenture in whole or in part at a redemption price equal to 120% of the 
Outstanding Principal Amount of this Debenture plus all accrued but unpaid 
interest and penalties on this Debenture.  Such Holder shall be entitled to 
make such election at any time after commencement and up to 10 days after the 
effective date of the Change in Control Transaction.  For purposes of this 
Paragraph 4, the commencement date shall be the day upon which the Change in 
Control Transaction was publicly announced.

     5.   CONVERSION AT THE OPTION OF THE HOLDER.  The Holder of this 
Debenture shall have the following conversion rights.

          (a)  HOLDER'S RIGHT TO CONVERT.  This Debenture shall be 
convertible at any time, in whole or in part, at the option of the Holder 
hereof, into fully paid, validly issued and nonassessable shares of Common 
Stock.  If this Debenture is converted in part, the remaining portion of this 
Debenture not so converted shall remain entitled to the conversion rights 
provided herein.

          (b)  CONVERSION PRICE FOR HOLDER CONVERTED SHARES.  The Outstanding 
Principal Amount of this Debenture that is converted into shares of Common 
Stock at the option of the Holder shall be convertible into the number of 
shares of Common Stock which results from application of the following 
formula:

                                     4
<PAGE>

                         P + I + D
                         ---------
                     Conversion Price

     P    =    Outstanding Principal Amount of this Debenture submitted for
               conversion
     I    =    accrued but unpaid interest (not previously added to principal)
               on P as of the Holder Conversion Date
     D    =    default payments (not previously added to principal) as of the
               Holder Conversion Date

     The number of shares of Common Stock into which each $1,000 principal 
amount of this Debenture hereto may be converted pursuant to this paragraph 
hereof is hereafter referred to as the "Conversion Rate."

          (c)  INITIAL CONVERSION PRICE.  Subject to adjustments pursuant to 
Sections 5 and 7, this Debenture will have a conversion price (the 
"Conversion Price") equal to 90.0% of the average of the Closing Bid Price 
for each of the ten (10) Trading Days immediately following, but not 
including, the Closing Date (such ten (10) Trading Day average being referred 
to as the "Closing Price"). The Holder shall deliver a notice to the Company 
on the eleventh Trading Day immediately following the Closing Date setting 
forth the calculation of the Conversion Price, which calculation shall be 
binding upon the Company absent manifest error in such calculation.

          (d)  PERIODIC ADJUSTMENTS TO THE CONVERSION PRICE.  If, at any time 
prior to the later of (x) the Registration Statement being declared effective 
by the SEC or (y) the 45 day anniversary of the Closing Date, the Closing Bid 
Price is for five (5) consecutive Trading Days (the fifth of such five (5) 
consecutive Trading Days being the "Periodic Reset Date") less than 50% of 
the Closing Price (such Closing Bid Price, multiplied by 90%, being known as 
the "Periodic Reset Price"), THEN the Company will deliver into the Holder's 
possession within three (3) Trading Days ("T+3") of the Periodic Reset Date, 
such number of additional shares of Common Stock as, together with such other 
shares of Common Stock as the Holder previously acquired as a result of the 
conversion of this Debenture, would result in such Holder having acquired in 
the aggregate a number of shares of Common Stock equal to the number that 
would have been acquired if all prior conversions had been at the Periodic 
Reset Price as the Conversion Price. Adjustments pursuant to this Section 
5(d) may occur multiple times.  If at the Interim Reset Date (defined below) 
the Interim Reset Price is greater than the Periodic Reset Price pursuant to 
which shares of Common Stock were delivered to the Holder under this 
paragraph (d), then the Holder will be required to return a portion of the 
shares previously delivered, so that the number of shares delivered pursuant 
to paragraphs (d) and (e) would be as determined at the Interim Reset Price.

          (e)  ADJUSTMENTS TO THE CONVERSION PRICE.  If the lesser of (i) the 
average of the Closing Bid Prices of the Common Stock for the twenty (20) 
consecutive Trading Days prior to but excluding the forty-five (45) calendar 
day anniversary of the day on which the Registration Statement is declared 
effective by the SEC (such 45 calendar day anniversary to be extended one day 
for each day during that period in which there is not Effective Registration) 
and (ii) the average of the Closing Bid Prices of the Common Stock for the 
twenty (20) consecutive Trading Days prior to but excluding the 60 calendar 
day anniversary of the Closing 

                                     5
<PAGE>

Date (such lesser price, multiplied by 90%, being known as the "Final Reset 
Price" and the date from which the Final Reset Price is calculated being 
known as the "Final Reset Date"), is less than the Closing Price, THEN if and 
only if such Final Reset Price is lower than the Conversion Price, (x) such 
Final Reset Price will automatically become the Conversion Price (subject to 
further adjustment) for all purposes of this Debenture, and (y) with respect 
to any shares issued to the Holder pursuant to Conversion Notices (as defined 
below) submitted after the day on which the Registration Statement is 
declared effective by the SEC and still held by such Holder on the Final 
Reset Date, the Company will deliver into the Holder's possession within T+3 
of the Final Reset Date, such number of additional shares of Common Stock (if 
any) as, together with such other shares of Common Stock as the Holder 
acquired pursuant to Conversion Notices (as defined below) submitted after 
the day on which the Registration Statement is declared effective by the SEC 
as a result of the conversion of this Debenture and which such Holder still 
holds on the Final Reset Date, would result in such Holder having acquired in 
the aggregate a number of shares of Common Stock equal to the number that 
would have been acquired if all such prior conversions had been at the Final 
Reset Price as the Conversion Price. An interim adjustment pursuant to this 
Section 5(e) shall be made on the earlier of the dates specified in clauses 
(i) and (ii) above (the "Interim Reset Date"), which price shall be the 
average specified in such clause (the "Interim Reset Price") and shall be 
effective until the Final Reset Date.

          (f)  ADJUSTMENTS TO CLOSING PRICE.  In the event that subsequent to 
the Closing Date and prior to or during any period of consecutive trading 
days provided for above, the Company shall pay any dividend on the Common 
Stock payable in Common Stock or in rights to acquire Common Stock, or shall 
effect a stock split or reverse stock split, then the Closing Price shall be 
proportionately decreased or increased, as appropriate, to give effect to 
such event.

          (g)  MECHANICS OF CONVERSION.  In order to convert this Debenture 
(in whole or in part) into full shares of Common Stock, the Holder shall 
surrender this Debenture, duly endorsed, by either overnight courier or 2-day 
courier, to the principal office of the Company, and shall give written 
notice in the form of EXHIBIT 1 hereto (the "Conversion Notice") by facsimile 
(with the original of such notice forwarded with the foregoing courier) to 
the Company at such office that the Holder elects to convert the principal 
amount (plus accrued but unpaid interest and default payments) specified 
therein, which such notice and election shall be revocable by the Holder at 
any time prior to its receipt of the Common Stock upon conversion; PROVIDED, 
HOWEVER, that the Company shall not be obligated to issue certificates 
evidencing the shares of the Common Stock issuable upon such conversion 
unless either the Debenture evidencing the principal amount is delivered to 
the Company as provided above, or the Holder notifies the Company that such 
Debenture(s) have been lost, stolen or destroyed and promptly executes an 
agreement reasonably satisfactory to the Company to indemnify the Company 
from any loss incurred by it in connection with such lost, stolen or 
destroyed Debentures.

     The Company shall issue and deliver within T+3 after delivery to the 
Company of such Conversion Notice, to such Holder of Debenture(s) at the 
address of the Holder, or to its designee, a certificate or certificates for 
the number of shares of Common Stock to which the Holder shall be entitled as 
aforesaid, together with a calculation of the Conversion Rate and a Debenture 
or Debentures for the principal amount of Debentures not submitted for 
conversion.  The date on which the Conversion Notice is given (the "Holder 
Conversion Date") shall be

                                     6
<PAGE>

deemed to be the date the Company received by facsimile the Conversion 
Notice, and the person or persons entitled to receive the shares of Common 
Stock issuable upon such conversion shall be treated for all purposes as the 
record holder or holders of such shares of Common Stock on such date.

     In lieu of delivering physical certificates representing the Common 
Shares issuable upon conversion of Debentures or the Warrant Shares (as 
defined in the Purchase Agreement) deliverable upon exercise of Warrants (as 
defined in the Purchase Agreement), provided the Company's transfer agent is 
participating in the Depository Trust Company ("DTC") Fast Automated 
Securities Transfer ("FAST") program, upon request of the holder, the Company 
shall use its best efforts to cause its transfer agent to electronically 
transmit the Common Shares and Warrant Shares issuable upon conversion or 
exercise to the Holder, by crediting the account of Holder's prime broker 
with DTC through its Deposit Withdrawal Agent Commission ("DWAC") system.  
The time periods for delivery described above shall apply to the electronic 
transmittals through the DWAC system.  The parties agree to coordinate with 
DTC to accomplish this objective.  The conversions pursuant to Sections 5 and 
6 shall be deemed to have been made immediately prior to the close of 
business on the Holder Conversion Date.  The person or persons entitled to 
receive the Common Shares issuable upon such conversion shall be treated for 
all purposes as the record holder or holders of such Common Shares at the 
close of business on the Holder Conversion Date.

     6.   CONVERSION UPON MATURITY.

          (a)  At the Forced Conversion Date, all Debentures outstanding at 
such time shall be automatically converted into Common Stock of the Company 
in accordance with the terms of this Debenture, the Purchase Agreement and 
the Registration Rights Agreement, without notice; PROVIDED, HOWEVER, that 
such conversion will be subject to the limitations on a Holder's right to 
convert as set forth in paragraph 12 below, and, PROVIDED FURTHER that the 
Forced Conversion Date shall be deferred for such number of days as is equal 
to 1.5 times the number of days (A) there is not Effective Registration but 
not including the first 90 days after the Closing; (B) there is not a 
sufficient amount of Common Shares available for conversion of all 
outstanding Debentures; or (C) for any other reason there is a default in, or 
failure of performance of, the obligations of the Company under this 
Debenture, the Purchase Agreement or the Registration Rights Agreement which 
interferes with the ability of the Holder to convert this Debenture or to 
freely sell without restriction the shares of Common Stock available upon 
conversion thereof.  The portion of the Outstanding Principal Amount of the 
Debenture that may not be converted by reason of such paragraph 12 limitation 
will be paid to the Holder by the Company in cash in an amount equal to 110% 
of the sum of (i) the Outstanding Principal Amount and (ii) accrued but 
unpaid interest and default payments ("Cash Payment").

     The Company shall issue and deliver within T+3 after delivery to the 
Company of this Debenture, or after receipt of the agreement and 
indemnification described in paragraph 5(c) above, to the Holder of the 
Debenture at the address of the Holder, or to its designee, a certificate or 
certificates for the number of shares of Common Stock to which the Holder 
shall be entitled hereunder, together with the Cash Payment and a calculation 
of the Conversion Rate.  The person or persons entitled to receive the shares 
of Common Stock issuable upon such conversion shall be treated for all 
purposes as the record holder or holders of such shares of Common Stock 

                                     7
<PAGE>

on the Forced Conversion Date.  The Forced Conversion Date shall be a "Holder 
Conversion Date" for purposes of this Debenture.

          (b)  Notwithstanding the preceding subparagraph (6)(a), no holder 
of Debentures shall be obligated to convert any Debentures held by such 
Holder on the Forced Conversion Date unless and until each of the following 
conditions has been satisfied or exists, each of which shall be a condition 
precedent to any such automatic conversion:

               (i)   no material default or breach exists, and no event shall 
have occurred which constitutes (or would constitute with notice or the 
passage of time or both) a material default or breach of the Purchase 
Agreement, the Registration Rights Agreement, any Warrant or this Debenture 
(for purposes of this clause (i), "material" shall mean materially affecting 
the business, affairs or prospects of the Company or the market for its 
securities, or having a material effect on the rights and benefits sought to 
be obtained by the Holders in acquiring the Debentures).

               (ii)  none of the events described in clauses (i) through (iv) 
of Section 2(b) of the Registration Rights Agreement shall have occurred and 
be continuing;

               (iii) Effective Registration (as defined in the Purchase 
Agreement) has occurred and is continuing and has continuously existed for 
the prior 60 consecutive trading days;

               (iv)  the Company and its direct and indirect subsidiaries on 
a consolidated basis has assets with a net realizable fair market value 
exceeding its liabilities and is able to pay all its debts as they become due 
in the ordinary course of business, and the Company is not and has not been 
subject to any liquidation, dissolution or winding up of its affairs; and

               (v)   each Holder of Debentures shall have received a 
certificate from an appropriate executive officer of the Company certifying 
that each of the foregoing conditions precedent exist or have been satisfied.

     The Company shall be given the opportunity after the Forced Conversion 
Date to cure the above conditions, and shall after effecting such cure give 
each Holder of Debentures ten (10) Trading Days' notice prior to an automatic 
conversion of such Holder's Debentures.  Such automatic conversion shall be 
subject to and governed by all the provisions relating to voluntary 
conversion of the Debentures contained herein.

     If the Company is not able to cure the above conditions, then (i) the 
Company has the right upon 60 days' prior written notice to the Holders, 
provided that such notice shall be effective if and only if the Company has 
had unrestricted freely trading Common Stock available for conversion by the 
Holders for the duration of the 60-day notice period and the Holders shall 
have had the opportunity to convert their Debentures during that period, and 
(ii) each Holder has the right to cause the Company, to redeem all Debentures 
outstanding at such time at a redemption price per Debenture equal to 120% of 
the sum of the Outstanding Principal Amount of the Debenture plus accrued but 
unpaid interest and default payments on the Debenture.

                                     8
<PAGE>

          (c)  The Company has no right to prepay this Debenture in whole or 
in part, or to pay this Debenture, except as set forth in this Section 6.

     7.   STOCK SPLITS; DIVIDENDS; ADJUSTMENTS; REORGANIZATIONS; PAYMENTS IN  
          LIEU OF CONVERSIONS.

          (a)  If the Company, at any time while the Debentures are 
outstanding, (i) shall pay a stock dividend or otherwise make a distribution 
or distributions on any equity securities (including investments or 
securities convertible into or exchangeable for such equity securities) in 
shares of Common Stock, (ii) issue any securities payable in shares of Common 
Stock, (iii) subdivide outstanding Common Shares into a larger number of 
shares, (iv) combine outstanding Common Stock into a smaller number of 
shares, the Conversion Price shall be multiplied by a fraction of which the 
numerator shall be the number of shares of Common Stock outstanding before 
such event and of which the denominator shall be the number of shares of 
Common Stock outstanding after such event.  Any adjustment made pursuant to 
this Section 7(a) shall become effective immediately after the record date 
for the determination of shareholders entitled to receive such dividend or 
distribution and shall become effective immediately after the effective date 
in the case of a subdivision or combination.

          (b)  In the event that the Company issues or sells any Common Stock 
or securities which are convertible into or exchangeable for its Common Stock 
or any convertible or exchangeable securities, or any warrants or other 
rights to subscribe for or to purchase or any options for the purchase of its 
Common Stock or any such convertible or exchangeable securities (other than 
shares or options issued pursuant to the Company's current employee or 
director option plans or stock purchase plans as amended consistent with the 
practice in the high-technology sector, at prices consistent with past 
practice or shares issued upon exercise of options, warrants or rights 
outstanding on the date of the Purchase Agreement and listed in Section 
2.1(c) of the Disclosure Schedule or pursuant to a Matridigm Transaction) at 
an effective purchase price per share which is less than the greater of the 
Conversion Price then in effect or the Market Price for Shares of the Common 
Stock on the trading day next preceding such issue or sale, then in each such 
case, the Conversion Price in effect immediately prior to such issue or sale 
shall be reduced effective concurrently with such issue or sale to an amount 
determined by multiplying the Conversion Price then in effect by a fraction, 
(x) the numerator of which shall be the sum of (1) the number of shares of 
Common Stock outstanding immediately prior to such issue or sale, plus (2) 
the number of shares of Common Stock which the aggregate consideration 
received by the Company for such additional shares would purchase at such 
Market Price for shares of Common Stock or Conversion Price, as the case may 
be, then in effect; and (y) the denominator of which shall be the number of 
shares of Common Stock of the Company outstanding immediately after such 
issue or sale.

     For the purposes of the foregoing adjustment, in the case of the 
issuance of any convertible or exchangeable securities, warrants, options or 
other rights to subscribe for or to purchase or exchange for, shares of 
Common Stock ("Exchangeable Securities"), the maximum number of shares of 
Common Stock issuable upon exercise, conversion or exchange of such 
Exchangeable Securities shall be deemed to be outstanding, provided that no 
further adjustment shall be made upon the actual issuance of Common Stock 
upon exercise, exchange or conversion of such Exchangeable Securities.

                                     9
<PAGE>

     In the event of any such issuance for a consideration which is less than 
such Market Price for Shares of Common Stock and also less than the 
Conversion Price then in effect, than there shall be only one such adjustment 
by reason of such issuance, such adjustment to be that which results in the 
greatest reduction of the Purchase Price computed as aforesaid.

          (c)  If the Company, at any time while the Debentures are 
outstanding, shall distribute to all holders of Common Shares evidences of 
its indebtedness or assets or rights or warrants to subscribe for or purchase 
any security (excluding those referred to in Section 7(b) above) then in each 
such case the Conversion Price at which the Debenture shall thereafter be 
convertible shall be determined by multiplying the Conversion Price in effect 
immediately prior to the record date fixed for determination of shareholders 
entitled to receive such distribution by a fraction of which the denominator 
shall be the Market Price for Shares of Common Stock determined as of the 
record date mentioned above, and of which the numerator shall be such Market 
Price for Shares of Common Stock on such record date less the then fair 
market value at such record date of the portion of such assets or evidence of 
indebtedness so distributed applicable to one outstanding Common Stock as 
determined by the Board of Directors in good faith; PROVIDED, HOWEVER that in 
the event of a distribution exceeding 25% of the net assets of the Company, 
such fair market value shall be determined at the Company's expense by a 
nationally recognized or major regional investment banking firm or firm of 
independent chartered accountants of recognized standing (which may be the 
firm that regularly examines the financial statements of the Company) (an 
"Appraiser") selected in good faith by the Board of Directors and Holders of 
a majority in interest of the Debentures.  In either case the adjustments 
shall be described in a statement provided to all holders of Debentures of 
the portion of assets or evidences of indebtedness so distributed or such 
subscription rights applicable to one Common Share.  Such adjustment shall be 
made whenever any such distribution is made and shall become effective 
immediately after the record date mentioned above.

          (d)  (i)   In the event that at any time or from time to time after 
the Closing Date, the Common Stock issuable upon the conversion of the 
Debentures is changed into the same or a different number of shares of any 
class or classes of stock, whether by merger, consolidation, 
recapitalization, reclassification or otherwise (other than a subdivision or 
combination of shares or stock dividend or reorganization provided for 
elsewhere in this Paragraph 7), then and as a condition to each such event 
provision shall be made so that each Holder of Debentures shall have the 
right thereafter to convert such Debenture into the kind of stock receivable 
upon such recapitalization, reclassification or other change by holders of 
shares of Common Stock, all subject to further adjustment as provided herein; 
provided that no further adjustment shall be made in connection with a 
Matridigm Transaction.  In such event, the formulae set forth herein for 
conversion and redemption shall be equitably adjusted to reflect such change 
in number of shares or, if shares of a new class of stock are issued, to 
reflect the market price of the class or classes of stock (applying the same 
factors used in determining the Conversion Price) issued in connection with 
the above described transaction.

               (ii)  If at any time or from time to time after the Closing 
Date there is a capital reorganization of the Common Stock, including by way 
of a sale of all or substantially all of the assets of the Company (other 
than a recapitalization, subdivision, combination, reclassification or 
exchange of shares provided for elsewhere in this Paragraph 7), then, as a 
part of and a condition to such reorganization, provision shall be made in a 
manner reasonably

                                     10
<PAGE>

acceptable to the Holders of the Debentures so that the Holders of the 
Debentures shall thereafter be entitled to receive upon conversion of the 
Debentures the number of shares of stock or other securities or property to 
which a holder of the number of shares of Common Stock deliverable upon 
conversion would have been entitled on such capital reorganization.  In any 
such case, appropriate adjustment shall be made in the application of the 
provisions of this Paragraph 7 with respect to the rights of the Holders of 
the Debentures after the reorganization to the end that the provisions of 
this Paragraph 7 shall be applicable after that event and be as nearly 
equivalent as may be practicable, including, by way of illustration and not 
limitation, by equitably adjusting the formulae set forth herein for 
conversion and redemption to reflect the market price of the securities or 
property (applying the same factors used in determining the Market Price for 
Shares of Common Stock) issued in connection with the above described 
transaction.

               (iii) In addition to the foregoing, if the holders of shares 
of Common Stock receive any non-publicly traded securities or other property 
or cash as part or all of the consideration for a reorganization, 
consolidation, merger or sale, then such distribution shall be treated to the 
extent thereof as a distribution under Section 7(c) above and such Section 
shall also apply to such distribution.  To the extent that, pursuant to the 
foregoing adjustments, (i) the Debentures become convertible into securities 
of an issuer with a greater number of outstanding shares of common stock than 
the Company and (ii) on the date of the relevant merger agreement or the date 
on which the terms of the restructuring are set, the Market Price is less 
than the Conversion Price, then the adjustments set forth in Section 7(b) 
herein shall also be applied as if the additional shares were issued after 
the effective date of the merger or reorganization.

          (e)  Whenever the Conversion Price is adjusted pursuant to Section 
7(a), (b), (c) or (d), the Company shall promptly mail to each Holder of the 
Debentures, a notice setting forth the Conversion Price after such adjustment 
and setting forth a brief statement of the facts requiring such adjustment.

          (f)  In the event of any taking by the Company of a record date of 
the holders of any class of securities for the purpose of determining the 
holders thereof who are entitled to receive any dividend or other 
distribution, any security or right convertible or exchangeable into or 
entitling the holder thereof to receive additional Common Shares, or any 
right to subscribe for, purchase or otherwise acquire any shares of stock of 
any class or any other securities or property, or to receive any other right, 
the Company shall deliver to each Holder of Debentures at least 20 days prior 
to the date specified therein, a notice specifying the date on which any such 
record is to be taken for the purpose of such dividend, distribution, 
security or right and the amount and character of such dividend, 
distribution, security or right.

          (g)  In no event shall the Company issue more than the Maximum 
Share Amount (as defined below and subject to adjustment as provided herein) 
upon conversion of this Debenture, unless the Company shall have obtained 
Stockholder Approval (as defined below) or a waiver of such requirement by 
NASDAQ.  As used herein, Stockholder Approval means approval by the 
stockholders of the Company in accordance with Rule 4460(i) of the rules of 
NASDAQ.  Once the Maximum Share Amount has been issued (the date of which is 
hereinafter referred to as the "Maximum Conversion Date"), unless the Company 
shall have obtained Stockholder Approval or a waiver of such requirement by 
NASDAQ, in lieu of any further right to convert this Debenture, and in full 
satisfaction of the Company's obligations under this 

                                     11
<PAGE>

Debenture, the Company shall pay to the Holder, within three (3) business 
days of the Maximum Conversion Date, an amount equal to the greater of (i) 
120% TIMES the sum of (a) the then outstanding principal amount of this 
Debenture immediately following the Maximum Conversion Date PLUS (b) accrued 
and unpaid interest on such principal amount PLUS (c) accrued and unpaid 
default payments and interest, if any, PLUS (d) any optional amounts that may 
be added thereto at the Maximum Conversion Date by the Holder in accordance 
with the terms hereof (the then outstanding principal amount of this 
Debenture immediately following the Maximum Conversion Date PLUS the amounts 
referred to in clauses (b), (c) and (d) above shall collectively be referred 
to as the "Remaining Convertible Amount"), or (ii) the Remaining Convertible 
Amount DIVIDED BY the Conversion Price (based on the five (5) consecutive 
Trading Days ending on the date which is two (2) trading days prior to the 
date of payment) MULTIPLIED BY the Closing Bid Price of the Common Stock on 
the Approved Market on the Trading Day immediately preceding the date of 
payment.  The Maximum Share Amount shall mean an aggregate of 4,284,603 
shares of Common Stock (19.9% of the Company's outstanding shares of Common 
Stock as of January 15, 1999 minus 75,000 shares reserved for issuance upon 
exercise of the Warrants), subject to equitable adjustments from time to time 
for stock splits, stock dividends, combinations, capital reorganizations and 
similar events relating to the Common Stock occurring after the date hereof.  
With respect to each Holder of Debentures, the Maximum Share Amount shall 
refer to such Holder's PRO RATA share thereof.  In the event that the Company 
obtains Stockholder Approval, the approval of NASDAQ or otherwise concludes 
that it is able to increase the number of shares to be issued above the 
Maximum Share Amount (such increased number being the "New Maximum Share 
Amount"), the references to Maximum Share Amount, above, shall be deemed to 
be, instead, references to the greater New Maximum Share Amount.  In the 
event that Stockholder Approval is not obtained or a registration statement 
covering the additional shares of Common Stock which constitute the New 
Maximum Share Amount is not effective prior to the Maximum Share Amount being 
issued (if such registration statement is necessary to allow for the public 
resale of such securities), the Maximum Share Amount shall remain unchanged; 
PROVIDED, HOWEVER, that the Holder may grant an extension of the effective 
date of such registration statement.  In the event that (a) the aggregate 
number of shares of Common Stock issued pursuant to this Debenture and the 
other Debentures issued on the Closing Date represents at least fifty percent 
(50%) of the Maximum Share Amount and (b) the sum of (x) the aggregate number 
of share of Common Stock issued pursuant to this Debenture and the other 
Debentures issued on the Closing Date PLUS (y) the aggregate number of shares 
of Common Stock that remain issuable pursuant to this Debenture and the other 
Debentures issued on the Closing Date and Warrants issued pursuant to the 
Purchase Agreement, represents at least one hundred percent (100%) of the 
Maximum Share Amount (the "Triggering Event"), the Company will use its best 
efforts to seek and obtain Stockholder Approval (or obtain such other relief 
as will allow conversions hereunder in excess of the Maximum Share Amount) as 
soon as practicable following the Triggering Event and before the Maximum 
Conversion Date.

     8.   FRACTIONAL SHARES.  No fractional shares of Common Stock or scrip 
representing fractional shares of Common Stock shall be issuable hereunder.  
The number of shares of Common Stock that are issuable upon any conversion 
shall be rounded up to the nearest whole share.

                                     12
<PAGE>

     9.   RESERVATION OF STOCK ISSUABLE UPON CONVERSION.

          (a)  RESERVATION REQUIREMENT.  So long as any Debentures remain 
outstanding the Company agrees to reserve and at all times keep available 
solely for purposes of conversion of Debentures such number of authorized but 
unissued shares of Common Stock that is set forth in Section 3.10 of the 
Purchase Agreement.

          (b)  DEFICIENCY.  If the Company does not have a sufficient number 
of shares of Common Stock available to satisfy the Company's obligations to a 
Holder of Debentures upon receipt of a Conversion Notice or is otherwise 
unable to issue such shares of Common Stock in accordance with the terms of 
this Agreement such Holder shall be entitled to the rights and remedies set 
forth in the Registration Rights Agreement.

     10.  NO REISSUANCE OF THE DEBENTURE.  No Debentures acquired by the 
Company by reason of redemption, purchase, exchange or otherwise shall be 
reissued, and all such Debentures shall be retired.

     11.  NO IMPAIRMENT.  The Company shall not intentionally take any action 
which would impair the rights and privileges of the Debentures set forth 
herein or the Holders thereof.

     12.  LIMITATIONS ON HOLDER'S RIGHT TO CONVERT.

          (a)  Notwithstanding anything to the contrary contained herein, no 
Debenture may be converted to the extent that, after giving effect to Common 
Shares to be issued pursuant to a Conversion Notice, the total number of 
shares of Common Stock deemed beneficially owned by such Holder (other than 
by virtue of the ownership of Debentures or ownership of other securities 
that have limitations on a Holder's rights to exchange, convert or exercise 
similar to those limitations set forth herein), together with all shares of 
Common Stock deemed beneficially owned by the holder's "affiliates" (as 
defined in Rule 144 of the Act) that would be aggregated for purposes of 
determining whether a group under Section 13(d) of the Securities Exchange 
Act of 1934, as amended, exists, would exceed 4.9% (the "Restricted Ownership 
Percentage") of the total issued and outstanding shares of the Company's 
Common Stock; PROVIDED that (w) each holder shall have the right at any time 
and from time to time to reduce its Restricted Ownership Percentage 
immediately upon notice to the Company, (x) each Holder shall have the right 
at any time and from time to time, to increase its Restricted Ownership 
Percentage and otherwise waive in whole or in part the restrictions of this 
Section 12(a) upon 61 days' prior notice to the Company or immediately in the 
event of the announcement of a pending or proposed Change in Control 
Transaction, (y) each holder can make subsequent adjustments pursuant to (w) 
or (x) any number of times from time to time (which adjustment shall be 
effective immediately if it results in a decrease in the percentage or shall 
be effective upon 61 days' prior written notice or immediately in the event 
of the announcement of a pending or proposed Change in Control Transaction if 
it results in an increase in the percentage) and (z) each Holder may 
eliminate or reinstate this limitation at any time and from time to time 
(which elimination will be effective upon 61 days' prior notice and which 
reinstatement will be effective immediately).  Without limiting the 
foregoing, in the event of the announcement of a pending or proposed Change 
in Control Transaction, any Holder may reinstate immediately (in whole or in 
part) the requirement that any increase in its Restricted Ownership 
Percentage be subject to 61 days' prior written 

                                     13
<PAGE>

notice, notwithstanding such Change in Control Transaction, without imposing 
such requirement on, or otherwise changing such Holder's rights with respect 
to, any other Change in Control Transaction.  For this purpose, any material 
modification of the terms of a Change in Control Transaction will be deemed 
to result in a new Change in Control Transaction.  The term "deemed 
beneficially owned" as used in this Debenture shall exclude shares that might 
otherwise be deemed beneficially owned by reason of the convertibility of the 
Debentures.  The Company shall provide all Holders with the earlier of (i) 20 
days' prior written notice of any such Change in Control Transaction, to the 
extent the Company has prior knowledge of a Change in Control Transaction; or 
(ii) notice on the day immediately following the Company's learning of any 
such transaction, but only after, in the case of (i) and (ii), such Change in 
Control Transaction has been publicly disclosed.

          (b)  Under certain circumstances specified in Section 3.15 of the 
Purchase Agreement, certain Debentures that are the subject of a Conversion 
Notice must be converted for cash.

     13.  SUBORDINATION.

          (a)  AGREEMENT TO SUBORDINATE.  Notwithstanding anything in this 
Debenture to the contrary, the Company agrees, and by accepting this 
Debenture the Holder agrees, that the indebtedness evidenced by this 
Debenture, solely to the extent that same is payable in cash and not in 
shares of Common Stock, is subordinate and subject in right of payment, to 
the extent and in the manner expressly provided in this Section 13, to the 
prior payment in full of all Senior Debt, and that the subordination is for 
the benefit of and enforceable by the holders of Senior Debt.  This Debenture 
shall in all respects rank senior to all other present and future obligations 
of the Company (other than trade debt), and only Senior Debt shall rank 
senior to this Debenture.

          (b)  INSOLVENCY, BANKRUPTCY, DISSOLUTION OF COMPANY.  Upon any 
payment or distribution (whether in cash, securities or other property) to 
creditors of the Company upon any Insolvency Event:

               (i)   all Senior Debt shall first be paid in full before the 
Holder shall be entitled to receive any payment or other distribution on or 
in respect of this Debenture; and

               (ii)  until all Senior Debt is paid in full, any payment or 
distribution to which the Holder of this Debenture would be entitled but for 
this Section 13 shall be made to holders of Senior Debt as their interests 
may appear, except that the Holder may receive shares of the Company as 
reorganized or readjusted or securities of the Company or any other 
corporation if the payment of such securities is subordinate to Senior Debt 
to at least the same extent as this Debenture is subordinate to Senior Debt.

          (c)  DEFAULT ON SENIOR DEBT.

               (i)   The Company may not pay the principal of, premium, if 
any, or interest on, this Debenture or make any deposit in respect of this 
Debenture (not including any reservation of Common Stock for purposes of the 
conversion of Debentures) and may not repurchase, redeem or otherwise retire 
this Debenture (collectively, "pay this Debenture") if (i) the principal of 
or interest on any Senior Debt is not paid when due or (ii) any other default 
on 

                                     14
<PAGE>

Senior Debt occurs and (ii) the maturity of such Senior Debt is accelerated 
in accordance with its terms unless, in each case, the default has been cured 
or waived and any such acceleration has been rescinded or such Senior Debt 
has been paid in full. During the continuance of any default (other than a 
default described in clause (i) and (ii) of the preceding sentence) with 
respect to any Senior Debt pursuant to which the maturity thereof may be 
accelerated immediately without further notice (except such notice as may be 
required to effect such acceleration) or the expiration of any applicable 
grace periods, the Company may not pay this Debenture for a period (a 
"Payment Blockage Period") commencing upon the receipt by the Company and the 
Holder of written notice of such default from a representative of such Senior 
Debt specifying an election to effect a Payment Blockage Period (a "Payment 
Blockage Notice") and ending 179 days thereafter (or earlier if such Payment 
Blockage Period is terminated (i) by written notice to the Company from the 
representative which gave such Payment Blockage Notice, (ii) by repayment in 
full of such Senior Debt or (iii) because the default specified in such 
Payment Blockage Notice is no longer continuing). Notwithstanding the 
immediately preceding sentence (but subject to the provisions contained in 
the first sentence of this Section), unless the holders of such Senior Debt 
or the representative of such holders shall have accelerated the maturity of 
such Senior Debt, the Company shall resume payments (including any missed 
payments) on this Debenture after the end of such Payment Blockage Period 
unless such payment is otherwise prohibited under this Section 13. Multiple 
Payment Blockage Periods may be imposed so long as (x) the cumulative period 
covered by all such Payment Blockage Periods does not exceed 179 days in any 
365 consecutive day period and (y) no more than one Payment Blockage Period 
may result from the same default.

               (ii)  The failure to make a payment or distribution on this 
Debenture by reason of this Section 13 shall not be construed or deemed to 
prevent the occurrence of an event of default hereunder; PROVIDED that any 
acceleration of payment of this Debenture resulting therefrom shall be 
rescinded if and when the following conditions shall be simultaneously 
satisfied:  (x) each payment or distribution which gave rise to such event of 
default shall be made and (y) no other such event of default shall have 
occurred.

          (d)  SUBORDINATED ACCELERATION; STANDSTILL.  The Holder agrees to 
give the Company not less than 5 days' prior written notice of its intention 
to accelerate the maturity of this Debenture pursuant to Section 4 hereof.  
The Company will promptly notify holders of Senior Debt of any obligation to 
make payments to be made under Section 7.

          (e)  PERMITTED PAYMENTS.  So as to eliminate any doubt, except (as 
to cash payments) as provided in Sections 13(b) and 13(c), payments under 
this Debenture, and payments under the Registration Rights Agreement (whether 
in cash or Common Stock (as applicable)) (collectively, "Permitted Payments") 
shall be made by the Company on the terms of this Debenture and Registration 
Rights Agreement, as the case may be.

          (f)  TURNOVER.  If the Holder receives any cash payment or other 
cash distribution on this Debenture (other than pursuant to a conversion) at 
a time when such payment or distribution should not have been made to the 
Holder by reason of this Section 13, such payment or distribution shall be 
deemed to have been received and held in trust for the benefit of the holders 
of the Senior Debt, and shall be segregated from other property of the Holder 
and be 

                                     15
<PAGE>

paid and delivered as promptly as practicable to the holders of the Senior 
Debt, as their interests may appear, for application to, or collateral for, 
the payment or prepayment of the Senior Debt.

          (g)  RELATIVE RIGHTS.  This Section 13 defines the relative rights 
of the Holder and the holders of Senior Debt.  Nothing herein shall:

               (i)   impair, as between the Company and the Holder, the 
obligation of the Company, which is absolute and unconditional, to pay 
principal of, premium, if any, and interest on this Debenture in accordance 
with its terms and to fulfill its other obligations hereunder; or

               (ii)  except as otherwise expressly provided herein, prevent 
the Holder from exercising its available remedies upon a default, subject to 
the rights of holders of Senior Debt to receive distributions otherwise 
payable to the Holder.

          (h)  AGREEMENT TO COOPERATE.  In the event that a payment may not 
be made on the Debentures as a result of the provisions of this Section 13, 
including without limitation, as a result of an Insolvency Event or a default 
on any Senior Debt, the Company shall, if requested by the Holder, reasonably 
assist the Holder in attempting to purchase such Senior Debt or otherwise 
cure such default so that the payment may be made on the Debenture.  Nothing 
in this Section 13(h) shall obligate the Holder to purchase such Senior Debt 
or to attempt to cure any such default.

          (i)  CONVERSION.  Notwithstanding anything to the contrary 
contained in this Section 13, nothing in this Section 13 shall restrict the 
rights of the Holder (i) to convert the Debenture in accordance with its 
terms, including, without limitation, after an Insolvency Event and during 
the pendency of a default on Senior Debt or (ii) to receive shares of Common 
Stock on account of interest payments due under this Debenture.

          (j)  DEFINITIONS.

               (i)   "Bank Credit Agreement" shall mean that certain credit 
agreement by and between the Company and Comerica Bank, as the same may be 
amended, supplemented or otherwise modified from time to time, as well as any 
future credit agreement that may be executed by the Company and Comerica Bank 
or another financial institution that replaces Comerica Bank as the Company's 
primary commercial bank or lending institution.

               (ii)  "Bankruptcy Code" means the Bankruptcy Reform Act of 
1978, 11 U.S.C. Section 101 ET SEQ., or any successor statute thereto.

               (iii) "Insolvency Event" means (i) any winding-up, insolvency, 
bankruptcy, liquidation or reorganization of the Company, whether voluntary 
or involuntary, (ii) any proceeding or case for reorganization, liquidation, 
bankruptcy, dissolution or other winding-up of the Company or its assets, 
whether or not involving insolvency or bankruptcy, (iii) any assignment by 
the Company for the benefit of creditors or (iv) any receivership or other 
similar proceeding or any marshalling of assets of the Company.

                                     16
<PAGE>

               (iv)  "Senior Debt" means all obligations and liabilities of 
the Company, whether for or on account of principal, reimbursement 
obligations, accrued and unpaid interest (including without limitation all 
interest accruing on and after an Insolvency Event), fees, expenses, 
indemnities and other amounts payable under or in connection with the Bank 
Credit Agreement and all documents or instruments executed in connection 
therewith, whether outstanding on the date of issuance of this Debenture or 
hereafter created, assumed or incurred, not to exceed $7,500,000 in the 
aggregate.

     14.  WAIVERS OF DEMAND, ETC.  The Company hereby expressly and 
irrevocably waives demand and presentment for payment, notice of nonpayment, 
protest, notice of protest, notice of dishonor, notice of acceleration or 
intent to accelerate, bringing of suit and diligence in taking any action to 
collect amounts called for hereunder and will be directly and primarily 
liable for the payment of all sums owing and to be owing hereon, regardless 
of and without any notice, diligence, act or omission as or with respect to 
the collection of any amount called for hereunder.

     15.  REPLACEMENT DEBENTURE.  In the event that any Holder notifies the 
Company that its Debenture(s) have been lost, stolen or destroyed, 
replacement Debenture(s) identical in all respects to the original 
Debenture(s) (except for registration number and Outstanding Principal 
Amount, if different than that shown on the original Debenture(s)), shall be 
issued to the Holder, provided that the Holder executes and delivers to the 
Company an agreement reasonably satisfactory to the Company to indemnify the 
Company from any loss incurred by it in connection with such Debenture.

     16.  PAYMENT OF EXPENSES; ISSUE TAXES.  The prevailing party in any 
litigation with respect to this Debenture shall be reimbursed by the losing 
party for all debts and expenses, including attorneys' fees, which may be 
incurred by such prevailing party in enforcing the provisions of this 
Debenture and/or collecting any amount due under this Debenture, the Purchase 
Agreement, any Warrant or the Registration Rights Agreement.  The Company 
shall pay any and all issue and other taxes (excluding any income, franchise 
or similar taxes) that maybe payable in respect of any issue or delivery of 
Common Shares on conversion of any Debenture pursuant hereto.

     17.  DEFAULTS.  If one or more of the following described "Events of 
Default" shall occur:

          (a)  The Company shall default in the payment of (i) interest on 
this Debenture, and such default shall continue for three (3) business days 
after the due date thereof, or (ii) the principal of this Debenture; or

          (b)  Any of the representations or warranties made by the Company 
herein, in the Purchase Agreement, the Registration Rights Agreement, any 
Warrant or in any certificate or financial or other statements heretofore or 
hereafter furnished by or on behalf of the Company in connection with the 
execution and delivery of this Debenture or such other documents shall be 
false or misleading in any material respect at the time made and the breach 
of which has (or with the passage of time will have) a material adverse 
effect on the rights of the Holder with respect to this Debenture, the 
Purchase Agreement or the Registration Rights Agreement or such effect 
substantially diminishes the value of the Holder's investment in the Company; 
or

                                     17
<PAGE>

          (c)  The Company shall fail in any material respect to perform or 
observe any covenant or agreement in the Purchase Agreement, or any other 
covenant, term, provision, condition, agreement or obligation of the Company 
under this Debenture and such failure shall continue uncured for a period of 
three (3) business days after notice from the Holder of such failure; or

          (d)  The Company shall (1) become insolvent; (2) admit in writing 
its inability to pay its debts generally as they mature; (3) make an 
assignment for the benefit of creditors or commence proceedings for its 
dissolution; or (4) apply for or consent to the appointment of a trustee, 
liquidator or receiver for it or for a substantial part of its property or 
business; or

          (e)  A trustee, liquidator or receiver shall be appointed for the 
Company or for a substantial part of its property or business without its 
consent and shall not be discharged within thirty (30) days after such 
appointment; or

          (f)  Any governmental agency or any court of competent jurisdiction 
at the instance of any governmental agency shall assume custody or control of 
the whole or any substantial portion of the properties or assets of the 
Company and shall not be dismissed within thirty (30) days thereafter; or

          (g)  The Company shall sell or otherwise transfer all or 
substantially all of its assets, if such sale or transfer is effected before 
thirty (30) days have elapsed after the Effectiveness Date, such 30 days to 
be extended one (1) day for each day after such date on which there is not 
Effective Registration; or

          (h)  Bankruptcy, insolvency or liquidation proceedings or other 
proceedings, under any bankruptcy law or any law for the relief of debt shall 
be instituted by or against the Company and, if instituted against the 
Company shall not be dismissed within thirty (30) days after such 
institution, or the Company shall by any action or answer approve of, consent 
to, or acquiesce in any such proceedings or admit to any material allegations 
of, or default in answering a petition filed in any such proceeding; or

          (i)  The Company shall be in default of any of its indebtedness 
that gives the holder thereof the right to accelerate $500,000 or more in 
such indebtedness; or

          (j)  A "going private" transaction under Rule 13e-3 promulgated 
pursuant to the Exchange Act shall have been announced; or

          (k)  A tender offer by the Company under Rule 13e-4 promulgated 
pursuant to the Exchange Act shall have been announced;

THEN, or at any time thereafter, and in each and every such case, unless such
Event of Default shall have been waived in writing by the Holder (which waiver
shall not be deemed to be a waiver of any subsequent default) at the option of
the Holder and in the Holder's sole discretion, the Holder may consider the
Debenture immediately due and payable, without presentment, demand, protest or
notice of any kind, all of which are hereby expressly waived, anything herein or
in any other instruments contained to the contrary notwithstanding, and the
Holder may immediately, and without expiration of any period of grace, enforce
any and all of the Holder's 

                                     18
<PAGE>

rights and remedies provided herein or any other rights or remedies afforded 
by law.  In such event, the Debenture shall be redeemed at a redemption price 
per Debenture equal to 120% of the Outstanding Principal Amount of the 
Debenture, plus accrued but unpaid interest and default payments on the 
Debenture.

     18.  SAVINGS CLAUSE.  In case any provision of this Debenture is held by 
a court of competent jurisdiction to be excessive in scope or otherwise 
invalid or unenforceable, such provision shall be adjusted rather than 
voided, if possible, so that it is enforceable to the maximum extent 
possible, and the validity and enforceability of the remaining provisions of 
this Debenture will not in any way be affected or impaired thereby, and such 
provision shall remain effective in all other jurisdictions.

     19.  ENTIRE AGREEMENT.  This Debenture and the agreements referred to in 
this Debenture constitute the full and entire understanding and agreement 
between the Company and the Holder with respect to the subject hereof.  
Neither this Debenture nor any term hereof may be amended, waived, discharged 
or terminated other than by a written instrument signed by the Company and 
the Holder.

     20.  ASSIGNMENT, ETC.  The Holder may transfer or assign this Debenture 
or any interest herein and may mortgage, encumber or transfer any of its 
rights or interest in and to this Debenture or any part hereof upon the 
consent of the Company (such consent not to be unreasonably withheld), and, 
without limitation, each assignee, transferee and mortgagee (which may 
include any affiliate of the Holder) shall have the right to transfer or 
assign its interest.  No such consent of the Company will be required for any 
transfer or assignment to (i) an affiliate or affiliates of the Holder or 
(ii) any person or entity whose investments are managed by an investment 
adviser that is the same as, or an affiliate of, the investment manager of 
the Holder.  Each such assignee, transferee and mortgagee shall have all of 
the rights of the Holder under this Debenture.  The Company agrees that, 
subject to compliance with the Purchase Agreement, after receipt by the 
Company of written notice of assignment from the Holder or from the Holder's 
assignee, all principal, interest and other amounts which are then and 
thereafter become due under this Debenture shall be paid to such assignee at 
the place of payment designated in such notice.  This Debenture shall be 
binding upon the Company and its successors and affiliates and shall inure to 
the benefit of the Holder and its successors and assigns.

     21.  NO WAIVER.  No failure on the part of the Holder to exercise, and 
no delay in exercising any right, remedy or power hereunder shall operate as 
a waiver thereof, nor shall any single or partial exercise by the Holder of 
any right, remedy or power hereunder preclude any other or future exercise of 
any other right, remedy or power.  Each and every right, remedy or power 
hereby granted to the Holder or allowed it by law or other agreement shall be 
cumulative and not exclusive of any other, and may be exercised by the Holder 
from time to time.

     22.  CERTIFICATE FOR CONVERSION PRICE ADJUSTMENT.  The Company shall, 
upon the written request at any time of any Holder of Debentures, furnish or 
cause to be furnished to such Holder a certificate prepared by the chief 
financial officer of Company setting forth any adjustments or readjustments 
of the Conversion Price pursuant to this Debenture.

                                     19
<PAGE>

     23.  NOTICES.  The Company shall distribute to the Holders of Debentures 
copies of all notices, materials, annual and quarterly reports, proxy 
statements, information statements and any other documents distributed 
generally to the holders of shares of Common Stock of the Company, at such 
times and by such method as such documents are distributed to such holders of 
such Common Stock, but shall not directly or indirectly provide material 
non-public information to the Holder without such Holder's prior written 
consent.

     24.  SPECIFIC ENFORCEMENT.  The Company agrees that irreparable damage 
would occur in the event that any of the provisions of this Debenture were 
not performed in accordance with their specific terms or were otherwise 
breached. It is accordingly agreed that the Holders of Debentures shall be 
entitled to swift specific performance, injunctive relief or other equitable 
remedies to prevent or cure breaches of the provisions of this Debenture and 
to enforce specifically the terms and provisions hereof, this being in 
addition to any other remedy to which any of them may be entitled under 
agreement, at law or in equity.

     25.  MISCELLANEOUS.  Unless otherwise provided herein, any notice or 
other communication to a party hereunder shall be sufficiently given if in 
writing and personally delivered, facsimiled or mailed to said party by 
certified mail, return receipt requested, at its address set forth herein or 
such other address as either may designate for itself in such notice to the 
other and communications shall be deemed to have been received when delivered 
personally or, if sent by mail or facsimile, then when actually received by 
the party to whom it is addressed.  Whenever the sense of this Debenture 
requires, words in the singular shall be deemed to include the plural and 
words in the plural shall be deemed to include the singular.  Paragraph 
headings are for convenience only and shall not affect the meaning of this 
document.

     26.  GOVERNING LAW; CONSENT TO JURISDICTION.  THIS DEBENTURE SHALL BE 
GOVERNED BY AND CONSTRUED AND ENFORCED IN ACCORDANCE WITH THE LAWS OF THE 
STATE OF NEW YORK APPLICABLE TO CONTRACTS TO BE EXECUTED AND PERFORMED 
ENTIRELY WITHIN SUCH STATE.  THE COMPANY (i) HEREBY IRREVOCABLY SUBMITS TO 
THE EXCLUSIVE JURISDICTION OF THE STATE AND FEDERAL COURT LOCATED IN NEW YORK 
COUNTY, NEW YORK FOR THE PURPOSES OF ANY SUIT, ACTION OR PROCEEDING ARISING 
OUT OF OR RELATED TO THIS DEBENTURE AND (ii) HEREBY WAIVES, AND AGREES NOT TO 
ASSERT IN ANY SUCH SUIT, ACTION OR PROCEEDING, ANY CLAIM THAT IT IS NOT 
PERSONALLY SUBJECT TO THE JURISDICTION OF SUCH COURT, THAT THE SUIT, ACTION 
OR PROCEEDING IS BROUGHT IN AN INCONVENIENT FORUM OR THAT THE VENUE OF THE 
SUIT, ACTION OR PROCEEDING IS IMPROPER.  THE COMPANY CONSENTS TO PROCESS 
BEING SERVED IN ANY SUCH SUIT, ACTION OR PROCEEDING BY MAILING A COPY THEREOF 
TO SUCH PARTY AS PROVIDED IN AND AGREES THAT SUCH SERVICE SHALL CONSTITUTE 
GOOD AND SUFFICIENT SERVICE OF PROCESS AND NOTICE THEREOF.  NOTHING IN THIS 
PARAGRAPH SHALL AFFECT OR LIMIT ANY RIGHT TO SERVE PROCESS IN ANY OTHER 
MANNER PERMITTED BY LAW.

                                     20
<PAGE>

     IN WITNESS WHEREOF, the Company has caused this instrument to be duly 
executed by an officer thereunto duly authorized.

Dated:
      ------------------------------------

ZITEL CORPORATION

By:
      ------------------------------------

Name:
     Title:
     Address:  47211 Bayside Parkway
               Fremont, California  94538




[SIGNATURE PAGE TO 3% CONVERTIBLE SUBORDINATED DEBENTURE OF ZITEL CORPORATION]

                                     21
<PAGE>

                                  EXHIBIT 1

                     (To be Executed by Registered Holder
                        in order to Convert Debenture)

                              CONVERSION NOTICE
                                     FOR
          3% CONVERTIBLE SUBORDINATED DEBENTURE DUE FEBRUARY 1, 2000

          The undersigned, as Holder of the 3% Convertible Subordinated 
Debenture Due February 1, 2000 of ZITEL CORPORATION (the "Company"), in the 
outstanding principal amount of U.S.$_____________ (the "Debenture"), hereby 
irrevocably elects to convert that portion of the outstanding principal 
amount of the Debenture shown on the next page into shares of Common Stock, 
no par value per share (the "Common Stock"), of the Company according to the 
conditions of the Debenture, as of the date written below.  The undersigned 
hereby requests that share certificates for the Common Stock to be issued to 
the undersigned pursuant to this Conversion Notice be issued in the name of, 
and delivered to, the undersigned or its designee as indicated below.  If 
shares are to be issued in the name of a person other than the undersigned, 
the undersigned will pay all transfer taxes payable with respect thereto.  No 
fee will be charged to the Holder for any conversion, except for transfer 
taxes, if any.

          Holder acknowledges and confirms that the Common Stock issued 
pursuant to this Notice of Conversion has been or will be sold in accordance 
with the prospectus delivery requirements of the Securities Act of 1933, if 
applicable, or pursuant to an exemption under such Act.

Conversion Information:            NAME OF HOLDER:
                                                  ----------------------------

                                   By:
                                      ----------------------------------------
                                        Print Name:
                                        Print Title:

                                   Print Address of Holder:


                                   -------------------------------------------

                                   -------------------------------------------
                                   Issue Common Stock to:
                                                         ---------------------
                                   at:
                                      ----------------------------------------

                                   Electronically transmit and credit Common
                                   Stock to:
                                            ----------------------------------
                                          at:
                                   ------     --------------------------------

                                   -------------------------------------------
                                   Date of Conversion

                                   -------------------------------------------
                                   Applicable Conversion Rate

                 THE COMPUTATION OF THE NUMBER OF COMMON SHARES TO
                   BE RECEIVED IS SET FORTH ON THE ATTACHED PAGE

                                     
<PAGE>

Page 2 to Conversion Notice for:
                                -----------------------------------------------
                                                (Name of Holder)
                                     
           COMPUTATION OF NUMBER OF COMMON SHARES TO BE RECEIVED

<TABLE>
<S>                                                                             <C>

A.   Outstanding Principal Amount converted:                                    $
B.   Accrued, unpaid interest on Outstanding Principal Amount converted:        $
C.   Default payments due Holder:                                               $
                                                                                --------

TOTAL DOLLAR AMOUNT CONVERTED (TOTAL OF A + B + C)                              $
                                                                                ========

CONVERSION PRICE                                                                $

NUMBER OF SHARES OF COMMON STOCK =   Total dollar amount Converted =            $
                                     ---------------------------------          --------
                                     Conversion Price
</TABLE>

If the conversion is not being settled by DTC, please issue and deliver _____ 
certificate(s) for shares of Common Stock in the following amount(s):

- -------------------------------------------------------------------------------

- -------------------------------------------------------------------------------

- -------------------------------------------------------------------------------

- -------------------------------------------------------------------------------

Please issue and deliver _____ new Debenture(s) in the following amounts:

- -------------------------------------------------------------------------------

- -------------------------------------------------------------------------------

- -------------------------------------------------------------------------------

- -------------------------------------------------------------------------------





<PAGE>

                                 EXHIBIT 4.2

                      CONVERTIBLE SUBORDINATED DEBENTURE

                              PURCHASE AGREEMENT

     CONVERTIBLE SUBORDINATED DEBENTURE PURCHASE AGREEMENT ("Agreement") 
dated as of February 2, 1999 between ZITEL CORPORATION, a California 
corporation (the "Company"), and each person or entity listed as an investor 
on Schedule I attached to this Agreement (each individually an "Investor" and 
collectively the "Investors").

                                  WITNESSETH

     WHEREAS, the Company desires to sell and issue to the Investors, and the 
Investors wish to purchase from the Company, 3% Convertible Subordinated 
Debentures due February 1, 2000 (the "Debentures"), in the aggregate 
principal amount of $5,000,000 at an aggregate price of $5,000,000, having 
the rights and privileges set forth in the Debentures in the form of EXHIBIT 
1.1A attached hereto (the "Issuance"), on the terms and conditions set forth 
herein; and

     WHEREAS, the Debentures will be convertible into shares ("COMMON 
SHARES") of common stock, no par value of the Company ("COMMON STOCK"), 
pursuant to the terms of the Debentures, and the Investors will have 
registration rights with respect to such Common Shares and the Warrant Shares 
(as defined herein), pursuant to the terms of that certain Registration 
Rights Agreement to be entered into between the Company and the Investors 
substantially in the form of EXHIBIT 4.2(f) hereto ("REGISTRATION RIGHTS 
AGREEMENT"); and

     WHEREAS, to induce the Investors to purchase the Debentures, the Company 
has agreed to issue to the Investors warrants exercisable for 75,000 shares 
of Common Stock, in the form attached as EXHIBIT 1.1B (the "WARRANTS");

     NOW, THEREFORE, in consideration of the foregoing premises and the 
covenants contained herein and other good and valuable consideration, the 
receipt and sufficiency of which are hereby acknowledged, the parties hereto 
agree as follows:

                                   ARTICLE 1

                 PURCHASE AND SALE OF DEBENTURES AND WARRANTS

     1.1  ISSUANCE OF DEBENTURES AND WARRANTS.  Upon the following terms and 
conditions, the Company shall issue and sell to each Investor severally, and 
each Investor severally shall purchase from the Company, the outstanding 
principal amount of Debentures indicated next to such Investor's name on 
Schedule I attached hereto.

          (a)  ISSUANCE.  Upon the following terms and conditions, the 
Company shall issue and sell to each Investor severally, and each Investor 
severally shall purchase from the 


                                      1
<PAGE>

Company, the principal amount of Debentures and the number of Warrants 
indicated next to such Investor's name on SCHEDULE I attached hereto.

          (b)  PURCHASE PRICE.  The purchase price for the Debentures to be 
acquired by each Investor (the "PURCHASE PRICE") shall be the Purchase Price 
set forth next to such Investor's name on SCHEDULE I.

          (c)  THE CLOSING.

               (i)   The closing of the purchase and sale of the Debentures 
and the Warrants (the "Closing"), shall take place at 10:00 am., local time 
on the later of the following:  (x) February 2, 1999, (y) the date on which 
the last to be fulfilled or waived of the conditions set forth in Article IV 
hereof and applicable to the Closing shall be fulfilled or waived in 
accordance herewith, or (z) such other time and place and/or on such other 
date as the Investors and the Company may agree.  The date on which the 
Closing occurs is referred to herein as the "Closing Date".

               (ii)  On the Closing Date, the Company shall deliver to each 
Investor (x) certificates (with the number of and outstanding principal 
amount of such certificates requested by such Investor) representing the 
Debentures purchased hereunder by such Investor at the Closing registered in 
the name of such Investor or its nominee and (y) the Warrants registered in 
the name of Investor or its nominee in such denominations as reasonably 
requested by such Investor, and such Investor shall deliver to the Company 
the Purchase Price for the Debentures purchased by such Investor hereunder by 
wire transfer in immediately available funds to an account designated in 
writing by the Company. The delivery of payment by each Investor of the 
Purchase Price applicable to it as set forth in this paragraph shall 
constitute a payment delivered to the Company in satisfaction of such 
Investor's obligation to pay the Purchase Price hereunder.  In addition, each 
party shall deliver all documents, instruments and writings required to be 
delivered by such party pursuant to this Agreement at or prior to the 
applicable Closing.  Notwithstanding anything to the contrary herein, the 
Closing may be conducted through LaSalle National Bank, 135 South LaSalle 
Street, Chicago, Illinois 60603 (the "Escrow Agent") as set forth in that 
certain escrow agreement dated as of January 27, 1999 among the Company, the 
Escrow Agent and Rochon Capital Group, Ltd.

                                   ARTICLE 2

                        REPRESENTATIONS AND WARRANTIES

     2.1  REPRESENTATIONS AND WARRANTIES OF THE COMPANY.  The Company hereby 
makes the following representations and warranties to each of the Investors 
as of the date hereof and on each Closing Date:

          (a)  ORGANIZATION AND QUALIFICATION; MATERIAL ADVERSE EFFECT.  The 
Company is a corporation duly incorporated and existing in good standing 
under the laws of the State of California and has the requisite corporate 
power to own its properties and to carry on its business as now being 
conducted.  The Company does not have any direct or indirect subsidiaries 
other than the subsidiaries listed in Section 2.1(a) of the Company's 
disclosure 


                                      2
<PAGE>

schedule delivered to the Investors and attached hereto (the "Disclosure 
Schedule").  Except where specifically indicated to the contrary, all 
references in this Agreement to subsidiaries shall be deemed to refer to all 
direct and indirect subsidiaries of the Company.  The Company is duly 
qualified as a foreign corporation to do business and is in good standing in 
every jurisdiction in which the nature of the business conducted or property 
owned by it makes such qualification necessary other than those in which the 
failure so to qualify would not have a Material Adverse Effect.  "MATERIAL 
ADVERSE EFFECT" means any adverse effect on the business, operations, 
properties, prospects, or financial condition of the entity with respect to 
which such term is used and which is (either alone or together with all other 
adverse effects) material to such entity and other entities controlling or 
controlled by such entity taken as a whole, and any material adverse effect 
on the transactions contemplated under this Agreement, the Registration 
Rights Agreement or any other agreement or document contemplated hereby or 
thereby.

          (b)  AUTHORIZATION; ENFORCEMENT.  (i) The Company has all requisite 
corporate power and authority to enter into and perform this Agreement, the 
Warrants and the Registration Rights Agreement and to issue the Debentures 
and Warrants in accordance with the terms hereof and thereof, (ii) the 
execution and delivery of this Agreement, the Warrants and the Registration 
Rights Agreement by the Company and the consummation by it of the 
transactions contemplated hereby and thereby, including the issuance of the 
Debentures, the Common Shares and the Warrant Shares have been duly 
authorized by all necessary corporate action, and no further consent or 
authorization of the Company or its Board of Directors (or any committee or 
subcommittee thereof) or stockholders is required, (iii) this Agreement, the 
Warrants, the Debentures and the Registration Rights Agreement have been duly 
executed and delivered by the Company, and (iv) this Agreement, the Warrants, 
the Debentures and the Registration Rights Agreement constitute valid and 
binding obligations of the Company enforceable against the Company in 
accordance with their terms, except as such enforceability may be limited by 
applicable bankruptcy, insolvency, reorganization, moratorium, liquidation or 
similar laws relating to, or affecting generally the enforcement of 
creditors' rights and remedies or by other equitable principles of general 
application.

          (c)  CAPITALIZATION.  As of January 15, 1999, the authorized 
capital stock of the Company consisted of 40,000,000 shares of Common Stock 
and 1,000,000 shares of preferred stock; there are 21,907,553 shares of 
Common Stock and no shares of preferred stock issued and outstanding; and 
3,402,031 shares of Common Stock and no shares of preferred stock are 
reserved for issuance to persons other than the Investors.  After the 
Closing, 3,402,031 shares of Common Stock and no shares of preferred stock 
will be reserved for issuance to persons other than the Investors.  All of 
the outstanding shares of the Company's Common Stock and preferred stock have 
been validly issued and are fully paid and nonassessable.  No shares of 
capital stock are entitled to preemptive rights; and there are as of the date 
hereof outstanding options for 1,861,551 shares of Common Stock and 150,000 
outstanding warrants for shares of Common Stock (excluding the Warrants).  
Except as set forth in Section 2.1(c) of the Disclosure Schedule, there are 
no other scrip, rights to subscribe to, calls or commitments of any character 
whatsoever relating to, or securities or rights exchangeable for or 
convertible into, any shares of capital stock of the Company, or contracts, 
commitments, understandings, or arrangements by which the Company is or may 
become bound to issue additional shares of capital stock of the Company or 
options, warrants, scrip, rights to subscribe to, or commitments to purchase 
or acquire, any shares, or securities or rights convertible or exchangeable 
into shares, of capital stock of the 


                                      3
<PAGE>

Company.  Attached hereto as EXHIBIT 2.1(c)(i) is a true and correct copy of 
the Company's Articles of Incorporation (the "CHARTER"), as in effect on the 
date hereof, and attached hereto as EXHIBIT 2.1(c)(ii) is a true and correct 
copy of the Company's By-Laws, as in effect on the date hereof (the 
"BY-LAWS").

          (d)  ISSUANCE OF COMMON SHARES.  The Common Shares and the shares 
of Common Stock issuable upon the exercise of the Warrants (the "WARRANT 
SHARES") are duly authorized and reserved for issuance and, upon such 
conversion in accordance with the Debentures and/or exercise in accordance 
with the Warrants such Common Shares and Warrant Shares will be validly 
issued, fully paid and non-assessable, free and clear of any and all liens, 
claims and encumbrances, and entitled to be traded on the Nasdaq National 
Market System ("NASDAQ NMS") (or the American Stock Exchange or the New York 
Stock Exchange, collectively with the Nasdaq NMS, the "APPROVED MARKETS"), 
and the holders of such Common Shares and Warrant Shares shall be entitled to 
all rights and preferences accorded to a holder of Common Stock.  The 
outstanding shares of Common Stock are currently listed on the Nasdaq NMS.

          (e)  NO CONFLICTS.  The execution, delivery and performance of this 
Agreement, the Registration Rights Agreement and the Warrants by the Company 
and the consummation by the Company of the transactions contemplated hereby 
and thereby and the issuance of the Debentures and the Warrants do not and 
will not (i) result in a violation of the Company's Charter or By-Laws or 
(ii) conflict with, or constitute a default (or an event which with notice or 
lapse of time or both would become a default) under, or give to others any 
rights of termination, amendment, acceleration or cancellation of, any 
agreement, indenture, patent, patent license or instrument to which the 
Company or any of its subsidiaries is a party, or (iii) result in a violation 
of any federal, state, local or foreign law, rule, regulation, order, 
judgment or decree (including Federal and state securities laws and 
regulations) applicable to the Company or any of its subsidiaries or by which 
any property or asset of the Company or any of its subsidiaries is bound or 
affected.  The business of the Company and its direct and indirect 
subsidiaries is being conducted in material compliance with all applicable 
laws, ordinances or regulations of any governmental entity.  The Company is 
not required under Federal, state, local or foreign law, rule or regulation 
to obtain any consent, authorization or order of, or make any filing or 
registration with, any court or governmental agency in order for it to 
execute, deliver or perform any of its obligations under this Agreement, the 
Registration Rights Agreement, the Debentures and the Warrants or issue and 
sell the Debentures in accordance with the terms hereof and issue the Common 
Shares upon conversion thereof and issue the Warrant Shares on exercise of 
the Warrants and for the registration provisions provided in the Registration 
Rights Agreement, except as specified herein and in the Registration Rights 
Agreement and the Warrant.

          (f)  SEC DOCUMENTS; NO NON-PUBLIC INFORMATION; FINANCIAL 
STATEMENTS. The Common Stock of the Company is registered pursuant to Section 
12(g) of the Securities Exchange Act of 1934, as amended (the "EXCHANGE ACT") 
and the Company has filed all reports, schedules, forms, statements and other 
documents required to be filed by it with the Securities and Exchange 
Commission ("SEC") pursuant to the reporting requirements of the Exchange 
Act, including material filed pursuant to Section 13(a) or 15(d), in addition 
to one or more registration statements and amendments thereto heretofore 
filed by the Company with the SEC 


                                      4
<PAGE>

(all of the foregoing including filings incorporated by reference therein 
being referred to herein as the "SEC DOCUMENTS").  The Company has delivered 
or made available to the Investors true and complete copies of all SEC 
Documents (including, without limitation, proxy information and solicitation 
materials and registration statements) filed with the SEC since September 30, 
1998, all annual SEC Documents filed with the SEC since September 30, 1997, 
and all press releases issued by the Company since May 28, 1998 as set forth 
in Section 2.1(f) of the Disclosure Schedule (the "Press Releases").  The 
Company has not directly or indirectly provided to the Investor any 
information that currently constitutes material non-public information or any 
information which, according to applicable law, rule or regulation, should 
have been disclosed publicly by the Company but which has not been so 
disclosed.  As of their respective dates, the SEC Documents complied in all 
material respects with the requirements of the Exchange Act and the rules and 
regulations of the SEC promulgated thereunder and other federal, state and 
local laws, rules and regulations applicable to such SEC Documents, and none 
of the SEC Documents contained any untrue statement of a material fact or 
omitted to state a material fact required to be stated therein or necessary 
in order to make the statements therein, in light of the circumstances under 
which they were made, not misleading.  The SEC Documents and Press Releases 
contain all material information concerning the Company, and no event or 
circumstance has occurred which would require the Company to disclose such 
event or circumstance in order to make the statements in the SEC Documents 
and the Press Releases not misleading on the date hereof or on the Closing 
Date but which has not been so disclosed.  The financial statements of the 
Company included in the SEC Documents comply as to form and substance in all 
material respects with applicable accounting requirements and the published 
rules and regulations of the SEC or other applicable rules and regulations 
with respect thereto.  Such financial statements have been prepared in 
accordance with United States generally accepted accounting principles 
(except (i) as may be otherwise indicated in such financial statements or the 
notes thereto or (ii) in the case of unaudited interim statements, to the 
extent they may not include footnotes or may be condensed or summary 
statements) and fairly present in all material respects the financial 
position of the Company as of the dates thereof and the results of operations 
and cash flows for the periods then ended (subject, in the case of unaudited 
statements, to normal year-end audit adjustments).

          (g)  PRINCIPAL EXCHANGE/MARKET.  The principal market on which the 
Common Stock is currently traded is the Nasdaq NMS.

          (h)  NO MATERIAL ADVERSE CHANGE.  Since September 30, 1998, no 
Material Adverse Effect has occurred or exists, and no event or circumstance 
which has not been disclosed in the SEC Documents and Press Releases has 
occurred that with notice or the passage of time or both is reasonably likely 
to result in a Material Adverse Effect with respect to the Company or its 
subsidiaries.

          (i)  NO UNDISCLOSED LIABILITIES.  Except as disclosed in Section 
2.1(i) of the Company Disclosure Schedule, the Company and its subsidiaries 
have no liabilities or obligations not disclosed in the SEC Documents or the 
Press Releases, other than those liabilities incurred in the ordinary course 
of the Company's or its subsidiaries' respective businesses since September 
30, 1998, which liabilities, individually or in the aggregate, do not or 
would not have a Material Adverse Effect on the Company or its direct or 
indirect subsidiaries.


                                      5
<PAGE>

          (j)  NO UNDISCLOSED EVENTS OR CIRCUMSTANCES.  No event or 
circumstance has occurred or exists with respect to the Company or its direct 
or indirect subsidiaries or their respective businesses, properties, 
prospects, operations or financial condition, which, under applicable law, 
rule or regulation, requires public disclosure or announcement by the Company 
but which has not been so publicly announced or disclosed.

          (k)  NO GENERAL SOLICITATION.  Neither the Company, nor any of its 
affiliates, or, to its knowledge, any person acting on its or their behalf 
has engaged in any form of general solicitation or general advertising 
(within the meaning of Regulation D under the Securities Act of 1933, as 
amended (the "Act")) in connection with the offer or sale of the Debentures 
or Common Shares.

          (l)  NO INTEGRATED OFFERING.  Neither the Company, nor any of its 
affiliates, nor to its knowledge any person acting on its or their behalf 
has, directly or indirectly, made any offers or sales of any security or 
solicited any offers to buy any security, under circumstances that would 
require registration of the Debentures, the Warrants or the Common Shares or 
Warrant Shares under the Act.  The issuance of the Debentures, Warrants, 
Common Shares, or Warrant Shares to the Investors will not be integrated with 
any other issuance of the Company's securities (past, current or future) 
which requires stockholder approval under the rules of the Nasdaq NMS.

          (m)  FORM S-3.  The Company is eligible to file a Registration 
Statement (as defined in the Registration Rights Agreement) on Form S-3 under 
the Act and rules promulgated thereunder for transactions involving secondary 
offerings, and Form S-3 is permitted to be used for the transactions 
contemplated by the Registration Rights Agreement involving secondary 
offerings under the Act and rules promulgated thereunder.

          (n)  INTELLECTUAL PROPERTY.  The Company (and/or its wholly-owned 
subsidiaries) owns or has licenses to use certain patents, copyrights and 
trademarks ("INTELLECTUAL PROPERTY") associated with its business.  The 
Company and its subsidiaries have all intellectual property rights which are 
material to the conduct of the business of the Company and its subsidiaries 
as it is now being conducted or as proposed to be conducted as disclosed in 
the SEC Documents.  The Company and its subsidiaries have no reason to 
believe that the intellectual property rights which it owns are invalid or 
unenforceable or that the use of such intellectual property by the Company or 
its subsidiaries infringes upon or conflicts with any right of any third 
party, and neither the Company nor any of its subsidiaries has received 
notice of any such infringement or conflict.  The Company and its 
subsidiaries have no knowledge of any material infringement of its 
intellectual property by any third party.

          (o)  SHAREHOLDER RIGHTS PLAN.  None of the acquisition of 
Debentures, Warrants, Common Shares or Warrant Shares nor the deemed 
beneficial ownership of shares of Common Stock prior to, or the acquisition 
of such shares pursuant to, the conversion of Debentures or the exercise of 
the Warrants will trigger the poison pill provisions of any stockholders' 
rights or similar agreements, or a substantially similar occurrence under any 
successor or similar plan.


                                      6
<PAGE>

          (p)  NO LITIGATION.  Except as set forth in Section 2.1(p) of the 
Disclosure Schedule, no litigation or claim (including those for unpaid 
taxes) against the Company or any of its subsidiaries is pending or, to the 
Company's knowledge, threatened, and no other event has occurred, which if 
determined adversely could reasonably be expected to have a Material Adverse 
Effect on the Company or could reasonably be expected to materially and 
adversely effect the transactions contemplated hereby.  The legal proceedings 
described in the Disclosure Schedule will not have an effect on the 
transactions contemplated hereby, and will not have a Material Adverse Effect 
on the Company.

          (q)  BROKERS.  The Company has taken no action which would give 
rise to any claim by any person for brokerage commissions, finder's fees or 
similar payments by the Company or any Investor relating to this Agreement or 
the transactions contemplated hereby, except for amounts owing to Rochon 
Capital Group, Ltd. which amounts shall be paid exclusively by the Company, 
pursuant to a separate agreement.

          (r)  ACKNOWLEDGEMENT OF DILUTION.  The number of shares of Common 
Stock constituting Common Shares or Warrant Shares may increase substantially 
in certain circumstances, including the circumstance where the trading price 
of the Common Stock declines.  The Company acknowledges that its obligation 
to issue Common Shares upon conversion of Debentures and Warrant Shares upon 
exercise of the Warrants is absolute and unconditional (except as limited by 
NASD Rule 4460(i) and any similar rule of any other Approved Market on which 
the Common Stock may then be trading, Section 12 of the Debentures and 
Section 9 of the Warrants), regardless of the dilution that such issuance may 
have on other shareholders of the Company.

          (s)  OTHER INVESTORS.  Except as set forth in Section 2.1(s) of the 
Disclosure Schedule, there are no outstanding securities issued by the 
Company that are entitled to registration rights under the Act.  Except as 
set forth in SCHEDULE 2.1(s), there are no outstanding securities issued by 
the Company that are directly or indirectly convertible into, exercisable 
into, or exchangeable for, shares of Common Stock of the Company, that have 
anti-dilution or similar rights that would be affected by the issuance of the 
Debentures, the Common Shares, the Warrant Shares or the Warrants.

          (t)  CERTAIN TRANSACTIONS.  Except as disclosed in the SEC 
Documents and Section 2.1(t) of the Disclosure Schedule, none of the 
officers, directors, or employees of the Company is presently a party to any 
material transaction with the Company or any of its subsidiaries (other than 
for services as employees, officers and directors), including any contract, 
agreement or other arrangement providing for the furnishing of services to or 
by, providing for rental of real or personal property to or from, or 
otherwise requiring payments to or from any officer, director or such 
employee or, to the knowledge of the Company, any corporation, partnership, 
trust or other entity in which any officer, director, or any such employee 
has a substantial interest or is an officer, director, trustee or partner.

          (u)  PERMITS; COMPLIANCE.  The Company and each of its subsidiaries 
is in possession of all material franchises, grants, authorizations, 
licenses, permits, easements, variances, exemptions, consents, certificates, 
approvals and orders necessary to own, lease and operate its properties and 
to carry on its business as it is now being conducted (collectively, the 


                                      7
<PAGE>

"COMPANY PERMITS"), and there is no action pending or, to the knowledge of 
the Company, threatened regarding suspension or cancellation of any of the 
Company Permits except for such Company Permits the failure of which to 
possess, or the cancellation or suspension of which, would not, individually 
or in the aggregate, have a material effect on the Company.  Neither the 
Company nor any of its subsidiaries is in material conflict with, or in 
material default or material violation of, any of the Company Permits.  Since 
September 30, 1998, neither the Company nor any of its subsidiaries has 
received any notification with respect to possible material conflicts, 
material defaults or material violations of applicable laws.

          (v)  INSURANCE.  The Company and each of its subsidiaries are 
insured by insurers of recognized financial responsibility against such 
losses and risks and in such amounts as management of the Company believes to 
be prudent and customary in the businesses in which the Company and its 
direct and indirect subsidiaries are engaged.  Neither the Company nor any 
such subsidiary has any reason to believe that it will not be able to renew 
its existing insurance coverage as and when such coverage expires or to 
obtain similar coverage from similar insurers as may be necessary to continue 
its business without a significant increase in cost.

          (w)  INTERNAL ACCOUNTING CONTROLS.  The Company and each of its 
subsidiaries maintain a system of internal accounting controls sufficient, in 
the judgment of the Company's board of directors, to provide reasonable 
assurance that (i) transactions are executed in accordance with management's 
general or specific authorizations, (ii) transactions are recorded as 
necessary to permit preparation of financial statements in conformity with 
generally accepted accounting principles and to maintain asset 
accountability, (iii) access to assets is permitted only in accordance with 
management's general or specific authorization and (iv) the recorded 
accountability for assets is compared with the existing assets at reasonable 
intervals and appropriate action is taken with respect to any differences.

          (x)  ENVIRONMENTAL MATTERS.  Except as otherwise disclosed in the 
SEC Documents, the Company and each of its subsidiaries is in compliance in 
all material respects with all applicable state and federal environmental 
laws and no event or condition has occurred that may interfere with the 
compliance by the Company or any of its subsidiaries with any environmental 
law or that may give rise to any liability under any environmental law that, 
individually or in the aggregate, would have a Material Adverse Effect.

          (y)  SOLVENCY.

               (i)   The Company's fair saleable value of its assets exceeds 
the amount that will be required to be paid on or in respect of the Company's 
existing debts and other liabilities (including contingent liabilities) as 
they mature.

               (ii)  The Company's assets do not constitute unreasonably 
small capital to carry out its business as now conducted and as proposed to 
be conducted including the Company's capital needs taking into account the 
particular capital requirements of the business conducted by the Company, and 
projected capital requirements and capital availability thereof.


                                      8
<PAGE>

               (iii) The Company does not intend to incur debts beyond its 
ability to pay such debts as they mature (taking into account the timing and 
amounts of cash to be payable on or in respect of its debt).

               (iv)  The Company does not intend, and does not believe, that 
final judgments against the Company in actions for money damages will be 
rendered at a time when, or in an amount such that, the Company will be 
unable to satisfy any such judgments promptly in accordance with their terms 
(taking into account the maximum reasonable amount of such judgments in any 
such actions and the earliest reasonable time at which such judgments might 
be rendered.  The Company's cash flow, after taking into account all other 
anticipated uses of the cash (including the payments on or in respect of debt 
referred to in paragraph (iii) above), will at all times be sufficient to pay 
all such judgments promptly in accordance with their terms.

     Neither the Company nor any of its subsidiaries is subject to any 
bankruptcy, insolvency or similar proceeding.

          (z)  TAXES.  All federal, state, city and other tax returns, 
reports and declarations required to be filed by or on behalf of the Company 
have been filed and such returns are complete and accurate and disclose all 
taxes (whether based upon income, operations, purchases, sales, payroll, 
licenses, compensation, business, capital, properties or assets or otherwise) 
required to be paid in the periods covered thereby.  All taxes shown on such 
returns and any deficiency assessments, penalties and interest have been 
paid.  All taxes required to be withheld by or on behalf of the Company in 
connection with amounts paid or owing to any employees, independent 
contractor, creditor or other party have been withheld, and such withheld 
taxes have either been duly and timely paid to the proper governmental 
authorities or set aside in accounts for such purposes.

     2.2  REPRESENTATIONS AND WARRANTIES OF THE INVESTORS.  Each of the 
Investors, severally (as to itself) and not jointly, hereby makes the 
following representations and warranties to the Company as of the date hereof 
and on the Closing Date:

          (a)  AUTHORIZATION; ENFORCEMENT.  (i) Such Investor has the 
requisite power and authority to enter into and perform this Agreement and 
the Registration Rights Agreement and to purchase the Debentures being sold 
hereunder and to acquire the Warrant, (ii) the execution and delivery of this 
Agreement and the Registration Rights Agreement by such Investor and the 
consummation by it of the transactions contemplated hereby and thereby have 
been duly authorized by all necessary corporate or partnership action, and 
(iii) this Agreement and the Registration Rights Agreement constitute valid 
and binding obligations of such Investor enforceable against such Investor in 
accordance with their terms, except as such enforceability may be limited by 
applicable bankruptcy, insolvency, reorganization, moratorium, liquidation or 
similar laws relating to, or affecting generally the enforcement of 
creditors' rights and remedies or by other equitable principles of general 
application.

          (b)  NO CONFLICTS.  The execution, delivery and performance of this 
Agreement and the Registration Rights Agreement and the performance under the 
Debentures and Warrants and the consummation by such Investor of the 
transactions contemplated hereby and thereby do not and will not (i) result 
in a violation of such Investor's organizational documents, or (ii) 


                                      9
<PAGE>

conflict with any agreement, indenture or instrument to which such Investor 
is a party, or (iii) result in a material violation of any law, rule, or 
regulation, or any order, judgment or decree of any court or governmental 
agency applicable to such Investor.  Such Investor is not required to obtain 
any consent or authorization of any governmental agency in order for it to 
perform its obligations under this Agreement, the Registration Rights 
Agreement, the Warrants or the Debentures.

          (c)  INVESTMENT REPRESENTATION.  Such Investor is purchasing the 
Debentures and the Warrants for its own account and not with a view to 
distribution in violation of any securities laws.  Such Investor has no 
present intention to sell the Debentures, Warrants, Common Shares, or Warrant 
Shares in violation of Federal or state securities laws and such Investor has 
no present arrangement (whether or not legally binding) to sell the 
Debentures, Warrants, Common Shares or Warrant Shares to or through any 
person or entity; provided, however, that by making the representations 
herein, such Investor does not agree to hold the Debentures, Warrants, Common 
Shares or Warrant Shares for any minimum or other specific term and reserves 
the right to dispose of the Debentures, Warrants, Common Shares or Warrant 
Shares at any time in accordance with Federal and state securities laws 
applicable to such disposition.

          (d)  ACCREDITED INVESTOR.  Such Investor is an "accredited 
investor" as defined in Rule 501 promulgated under the Act.  The Investor has 
such knowledge and experience in financial and business matters in general 
and investments in particular, so that such Investor is able to evaluate the 
merits and risks of an investment in the Debentures and to protect its own 
interests in connection with such investment.  In addition (but without 
limiting the effect of the Company's representations and warranties contained 
herein), such Investor has received such information as it considers 
necessary or appropriate for deciding whether to purchase the Debentures 
pursuant hereto.

          (e)  RULE 144.  Such Investor understands that there is no public 
trading market for the Debentures or Warrants, that none is expected to 
develop, and that the Debentures and Warrants and the Common Shares and 
Warrant Shares must be held indefinitely unless the Common Shares and Warrant 
Shares are registered under the Act or an exemption from registration is 
available.  Such Investor has been advised or is aware of the provisions of 
Rule 144 promulgated under the Act.

          (f)  BROKERS.  Such Investor has taken no action which would give 
rise to any claim by any person for brokerage commissions, finder's fees or 
similar payments by the Company relating to this Agreement or the 
transactions contemplated hereby, except for amounts owing to Rochon Capital 
Group, Ltd., which amounts will be paid exclusively by the Company, pursuant 
to a separate agreement.

          (g)  RELIANCE BY THE COMPANY.  Such Investor understands that the 
Debentures and Warrant are being offered and sold in reliance on a 
transactional exemption from the registration requirements of Federal and 
state securities laws and that the Company is relying upon the truth and 
accuracy of the representations, warranties, agreements, acknowledgments and 
understandings of such Investor set forth herein in order to determine the 
applicability of such exemptions and the suitability of such Investor to 
acquire the Debentures and Warrants.


                                      10
<PAGE>

                                   ARTICLE 3

                                   COVENANTS

     3.1  REGISTRATION AND LISTING; EFFECTIVE REGISTRATION.  Until such time 
as no Debentures or Warrants are outstanding, the Company will cause the 
Common Stock to continue at all times to be registered under Section 12(g) of 
the Exchange Act, will comply in all respects with its reporting and filing 
obligations under the Exchange Act, and will not take any action or file any 
document (whether or not permitted by the Exchange Act or the rules 
thereunder) to terminate or suspend such reporting and filing obligations.  
Until such time as no Debentures or Warrants are outstanding, the Company 
shall continue the listing or trading of the Common Stock on the Nasdaq NMS 
or one of the other Approved Markets and comply in all respects with the 
Company's reporting, filing and other obligations under the bylaws or rules 
of the Approved Market on which the Common Stock is listed.  The Company 
shall cause the Common Shares and the Warrant Shares to be listed on the 
Nasdaq NMS no later than the registration of the Common Shares or the Warrant 
Shares under the Act, and at all times shall continue such listing(s) on one 
of the Approved Markets.  As used herein and in the Registration Rights 
Agreement, the Debenture and the Warrants, the term "EFFECTIVE REGISTRATION" 
shall mean that all registration obligations of the Company pursuant to the 
Registration Rights Agreement and this Agreement have been satisfied, all 
Registrable Securities (as defined in the Registration Rights Agreement) have 
been registered for resale by the Investors, such registration is not subject 
to any suspension or stop order, the prospectus for the Common Shares 
issuable upon conversion of the Debentures and the Warrant Shares issuable 
upon exercise of the Warrants is current and such Common Shares and Warrant 
Shares are listed for trading on one of the Approved Markets and such trading 
has not been suspended for any reason, none of the Company or any direct or 
indirect subsidiary of the Company is subject to any bankruptcy, insolvency 
or similar proceeding, and no Interfering Event (as defined in Section 2(b) 
of the Registration Rights Agreement) exists.

     3.2  DEBENTURES ON CONVERSION AND WARRANTS ON EXERCISE.

          (a)  Upon any conversion by an Investor (or then holder of 
Debentures) of the Debentures pursuant to the terms thereof, the Company 
shall issue and deliver to such Investor (or holder) within three (3) Trading 
Days of the Conversion Date (as defined in the Debenture) a new certificate 
or certificates for the number of Debentures which such Investor (or holder) 
has not yet elected to convert but which are evidenced in part by the 
certificate(s) submitted to the Company in connection with such conversion 
(with the number of and denomination of such new certificate(s) designated by 
such Investor or holder).

          (b)  Upon any partial exercise by an Investor (or then holder of 
the Warrants) of the Warrants, the Company shall issue and deliver to such 
Investor (or holder) within three (3) days of the date on which such Warrants 
are exercised, a new Warrant or Warrants representing the number of adjusted 
Warrant Shares, in accordance with the terms of Section 2 of the Warrants.


                                      11
<PAGE>

     3.3  REPLACEMENT DEBENTURES AND WARRANTS.

          (a)  The certificate(s) representing the Debentures held by any 
Investor (or then holder) may be exchanged by such Investor (or such holder) 
at any time and from time to time for certificates with different 
denominations representing an equal aggregate number of Debentures, as 
requested by such Investor (or such holder) upon surrendering the same.  No 
service charge will be made for such registration or transfer or exchange.

          (b)  The Warrants will be exchangeable at the option of the 
Investor (or then holder of the Warrants) at the office of the Company for 
other Warrants of different denominations entitling the holder thereof to 
purchase in the aggregate the same number of Warrant Shares as are 
purchasable under such Warrants.  No service charge will be made for such 
transfer or exchange.

     3.4  EXPENSES.  The Company shall pay in immediately available funds, at 
the Closing and promptly upon receipt of any further invoices relating to 
same, all reasonable due diligence fees and expenses and attorneys' fees and 
expenses of Kleinberg, Kaplan, Wolff & Cohen, P.C. ("Investors' Counsel"), up 
to a maximum amount of $30,000, incurred by the Investors in connection with 
the preparation, negotiation, execution and delivery of this Agreement, the 
Registration Rights Agreement, the Debentures, the Warrants and the related 
agreements and documents and the transactions contemplated hereunder and 
thereunder.  At Closing, the Company shall pay the amount due for such fees 
and expenses (which may include fees and expenses estimated to be incurred 
for completion of the transaction including post-closing matters).  In the 
event such amount is ultimately less than the actual fees and expenses, the 
Company shall promptly pay such deficiency upon receipt of an invoice 
regarding same.

     3.5  SECURITIES COMPLIANCE. The Company shall notify the SEC and the 
Nasdaq NMS, in accordance with their requirements, of the transactions 
contemplated by this Agreement, the Debenture, the Registration Rights 
Agreement and the Warrants, and shall take all other necessary action and 
proceedings as may be required and permitted by applicable law, rule and 
regulation, for the legal and valid issuance of the Debentures hereunder, the 
Common Shares issuable upon conversion thereof, the Warrants and the Warrant 
Shares issuable upon exercise of the Warrants.

     3.6  DIVIDENDS OR DISTRIBUTIONS.  So long as any Debentures remain 
outstanding, the Company agrees that it shall not (a) declare or pay any 
dividends or make any distributions to any holder or holders of Common Stock, 
or (b) purchase or otherwise acquire for value, directly or indirectly, any 
Common Stock or other equity security of the Company.

     3.7  NOTICES.  The Company agrees to provide all holders of Debentures 
and Warrants with copies of all notices and information, including without 
limitation notices and proxy statements in connection with any meetings, that 
are provided to the holders of shares of Common Stock, contemporaneously with 
the delivery of such notices or information to such Common Stock holders.


                                      12
<PAGE>

     3.8  USE OF PROCEEDS.  The Company agrees that the proceeds received by 
the Company from the sale of the Debentures hereunder shall be used for 
working capital purposes and an investment in Matridigm Corporation.

     3.9  RIGHT OF FIRST REFUSAL; ADJUSTMENTS.

          (a)  Until the expiration of twelve (12) months from the Closing 
Date, the Company shall not (i) sell or otherwise issue or deliver any shares 
of Common Stock or other equity securities or any securities which are 
convertible into or exchangeable for shares of its Common Stock or other 
equity securities or any convertible or exchangeable security, or any 
warrants or other rights to subscribe for or to purchase or any options for 
the purchase of shares of Common Stock or other equity securities to any 
party other than the Investors or their affiliates (a "THIRD PARTY") (other 
than in a bona-fide public offering conducted on the basis of a firm 
commitment underwriting with a price to the public of at least $10,000,000 
and other than shares or options issued or which may be issued pursuant to 
the Company's currently existing employee or director option plans and 
employee stock purchase plans as such plans may be amended from time to time 
consistent with practices of other companies in the high-technology sector, 
shares issued upon exercise of options, warrants or rights outstanding on the 
Closing Date listed in Section 2.1(c) of the Disclosure Schedule or shares 
issued in a Matridigm Transaction (as defined in Section 7.17), or (ii) 
obtain any equity or equity related financing from any Third Party, unless 
such offer, sale, issuance or financing ("FINANCING TRANSACTION") is first 
offered to the Investors.  The Company shall make such offer by providing 
each Investor with written notice of the Company's intention to enter into 
the Financing Transaction with such Third Party together with a term sheet 
identifying all such Third Parties and containing all the economic terms and 
significant provisions of the Financing Transaction (the "OFFER").  Such 
Offer shall be given with respect to each Financing Transaction negotiated by 
the Company with any Third Party.  The Investors shall have ten (10) business 
days from receipt of the Offer to deliver a written notice to the Company 
that the Investors wish to accept the Offer in whole but not in part (subject 
to satisfactory due diligence and reasonably acceptable definitive 
documentation) for the Financing Transaction.  If certain Investors choose 
not to participate, the other Investors may increase their participation on a 
proportional basis.  If the Investors reject the Offer entirely or fail to 
respond within such ten (10) business day period, then the Company shall be 
permitted to complete such Financing Transaction with the Third Party within 
thirty (30) days on terms and conditions identical to those contained in the 
Offer.  If any Financing Transaction is contemplated on terms and conditions 
not identical to those contained in the Offer or with definitive 
documentation not identical to that proposed by the Company with respect to 
the Offer or if such Financing Transaction is not consummated with such Third 
Party within 30 days, then such Financing Transaction shall be deemed a new 
Financing Transaction and the Investors shall again be entitled to receive an 
Offer for such Financing Transaction on such new terms and conditions (and/or 
with such new definitive documentation if applicable) or upon the same terms 
if the Third Party fails to consummate the Financing Transaction in the 
period specified in this sentence. The rights of the Investors under this 
paragraph 3.9 (a) as to any securities, instruments or rights issued which 
are exercisable or exchangeable for, or convertible into, shares of Common 
Stock, where (i) the exercise, exchange or conversion price is at a discount 
of 10% or greater from the then market price of the Common Stock, or (ii) 
holders of such securities, instruments or rights may acquire additional 
shares of Common Stock as a result of a 


                                      13
<PAGE>

one-time or periodic adjustments to the exercise, exchange or conversion 
price, shall survive a Change of Control Transaction, as defined in the 
Debenture.

          (b)  If at any time within twelve (12) months from the Closing Date 
the Company issues Common Stock (or securities or rights exercisable or 
exchangeable for, or convertible into, Common Stock) in a private placement 
at a discount greater than the discount specified in Section 5(c) of the 
Debentures or at a ceiling, conversion, exercise or exchange price less than 
the Conversion Price (as defined in the Debentures and as adjusted pursuant 
to the terms thereof), then the Debentures will automatically (at the 
Investor's request) be adjusted to provide for such greater discount or lower 
or more favorable conversion, exercise or exchange price, as applicable.  
This paragraph 3.9 (b) shall not apply to issuances pursuant to currently 
existing employee or director option or stock purchase plans as such plans 
may be amended from time to time consistent with practices of other companies 
in the high-technology sector, issuances in a Matridigm Transaction or with 
respect to the items listed in Section 2.1(c) of the Disclosure Schedule.

     3.10 RESERVATION OF STOCK ISSUABLE UPON CONVERSION AND UPON EXERCISE OF 
THE WARRANTS.  The Company shall at all times reserve and keep available out 
of its authorized but unissued shares of Common Stock, solely for the purpose 
of effecting the conversion of the Debentures and the exercise of the 
Warrants, such number of its shares of Common Stock as shall from time to 
time be sufficient to effect the conversion of all outstanding Debentures and 
the full exercise of the Warrants and if at any time the number of authorized 
but unissued shares of Common Stock shall not be sufficient to effect the 
conversion of all the then outstanding Debentures, the full exercise of the 
Warrants, the Company will take such corporate action as may, in the opinion 
of its counsel, be necessary to increase its authorized but unissued shares 
of Common Stock to such number of shares as shall be sufficient for such 
purpose, including without limitation engaging in best efforts to obtain the 
requisite shareholder approval.  Without in any way limiting the foregoing, 
the Company agrees to reserve and at all times keep available solely for 
purposes of conversion of Debentures and the exercise of the Warrants such 
number of authorized but unissued shares of Common Stock that is at least 
equal to 200% of the aggregate shares issuable upon conversion of Debentures, 
and 200% of the aggregate shares issuable on exercise of Warrants, which 
number may be reduced by the number of Common Shares or Warrant Shares 
actually delivered pursuant to conversion of Debentures or exercise of the 
Warrants and shall be appropriately adjusted for any stock split, reverse 
split, stock dividend or reclassification of the Common Stock.  When the 
adjustments to the Conversion Price (as defined in the Debenture) pursuant to 
Sections 5(d) and 5(e) of the Debenture have been completed, the percentages 
set forth in the preceding sentence shall be reduced from "200%" to "103%".  
If the Company falls below the reserves specified in the immediately 
preceding sentence and does not cure such non-compliance within 30 days of 
its start, then the Investors will be entitled to the discount adjustments 
specified in Section 2(b)(i) of the Registration Rights Agreement. If at any 
time the number of authorized but unissued shares of Common Stock is not 
sufficient to effect the conversion of all the then outstanding Debentures or 
the full exercise of the Warrants, the Investors shall be entitled to, INTER 
ALIA, the premium price redemption rights provided in the Registration Rights 
Agreement.  The Company shall not be permitted to engage in any transaction 
if, after giving effect thereto, the Company would not be in compliance with 
the reservation requirements of this Section 3.10.


                                      14
<PAGE>

     3.11 BEST EFFORTS.  The parties shall use their best efforts to satisfy 
timely each of the conditions described in Article IV of this Agreement.

     3.12 FORM D; BLUE SKY LAWS.  The Company agrees to file a Form D with 
respect to the Debentures, Warrants, Common Shares and Warrant Shares, as 
required under Regulation D and to provide a copy thereof to each Investor 
promptly after such filing.  The Company shall, on or before each Closing 
Date, take such action as the Company shall have reasonably determined is 
necessary to qualify the Debentures, Warrants, Common Shares and Warrant 
Shares for sale to the Investors at the applicable Closing pursuant to this 
Agreement under applicable securities or "blue sky" laws of the states of the 
United States (or to obtain an exemption from such qualification), and shall 
provide evidence of any such action so taken to each Investor on or prior to 
the Closing Date.

     3.13 NO SENIOR INDEBTEDNESS; LIMITATIONS ON ISSUANCE OF EQUITY.

          (a)  So long as any Debentures remain outstanding, the Company 
agrees that neither the Company nor any direct or indirect subsidiary of the 
Company shall create, incur, assume, guarantee, secure or in any manner 
become liable in respect of any indebtedness, except for Senior Debt as 
defined in the Debenture, debt owed to a financial institution which debt is 
unsecured other than by accounts receivable or trade payables incurred in the 
ordinary course of business consistent with past practices or debt pursuant 
to a Matridigm Transaction, unless junior to the Debentures in all respects.  
For purposes of this Section 3.13, "financial institution" excludes, without 
limitation, any investment company, or any entity that would be an investment 
company, but for the exclusions provided by Section 3(c)(1) or Section 
3(c)(7) of the Investment Company Act of 1940, as amended.

          (b)  Until the Registration Statement (as defined in the 
Registration Rights Agreement) has been declared effective by the SEC and the 
Common Shares are subject to Effective Registration, neither the Company nor 
any of its subsidiaries will issue any equity securities or instruments or 
rights convertible into or exchangeable or exercisable for any equity 
securities, except pursuant to current employee and director option and stock 
purchase plans in amounts and at prices consistent with past practice, in a 
Matridigm Transaction and with respect to items listed in Section 2.1(c) of 
the Disclosure Schedule.
                                     
                                 ARTICLE 4

                          CONDITIONS TO CLOSINGS

     4.1  CONDITIONS PRECEDENT TO THE OBLIGATION OF THE COMPANY TO SELL THE 
DEBENTURES.  The obligation hereunder of the Company to issue and/or sell the 
Debentures to the Investors at the Closing (unless otherwise specified) is 
subject to the satisfaction, at or before the Closing, of each of the 
applicable conditions set forth below.  These conditions are for the 
Company's sole benefit and may be waived by the Company at any time in its 
sole discretion.

          (a)  ACCURACY OF THE INVESTORS' REPRESENTATIONS AND WARRANTIES.  
The representations and warranties of each Investor will be true and correct 
in all material respects as of the date when made and as of the Closing Date 
as though made at that time (except for 


                                      15

<PAGE>

representations and warranties as of an earlier date, which shall have been 
true and correct in all material respects as of such date).

          (b)  PERFORMANCE BY THE INVESTORS.  Each Investor shall have 
performed all agreements and satisfied all conditions required to be 
performed or satisfied by such Investor at or prior to the Closing.

          (c)  NO INJUNCTION. No statute, rule, regulation, executive order, 
decree, ruling or injunction shall have been enacted, entered, promulgated or 
endorsed by any court or governmental authority of competent jurisdiction 
which prohibits the consummation of any of the transactions contemplated by 
this Agreement or the Registration Rights Agreement or the Debentures or the 
Warrants.

     4.2  CONDITIONS PRECEDENT TO THE OBLIGATION OF THE INVESTORS TO PURCHASE 
THE DEBENTURES.  The obligation hereunder of each Investor to acquire and pay 
for the Debentures at the Closing (unless otherwise specified) is subject to 
the satisfaction, at or before the Closing, of each of the applicable 
conditions set forth below.  These conditions are for each Investor's benefit 
and may be waived by each Investor at any time in its sole discretion.

          (a)  ACCURACY OF THE COMPANY'S REPRESENTATIONS AND WARRANTIES.  The 
representations and warranties of the Company shall be true and correct in 
all material respects as of the date when made and as of the Closing Date as 
though made at that time (except for representations and warranties as of an 
earlier date, which shall have been true and correct in all material respects 
as of such date).

          (b)  PERFORMANCE BY THE COMPANY.  The Company shall have performed 
all agreements and satisfied all conditions required to be performed or 
satisfied by the Company at or prior to the Closing.

          (c)  NASDAQ NMS.  From the date hereof to the Closing Date, trading 
in the Company's Common Stock shall not have been suspended by the SEC or the 
Nasdaq NMS (or other Approved Market), and trading in securities generally as 
reported by the Nasdaq NMS (or other Approved Market) shall not have been 
suspended or limited, and the Common Stock shall not have been delisted from 
the Nasdaq NMS (or any other Approved Market where they are currently listed).

          (d)  NO INJUNCTION.  No statute, rule, regulation, executive, 
judicial or administrative order, decree, ruling or injunction shall have 
been enacted, entered, promulgated or endorsed by any court or governmental 
authority of competent jurisdiction which prohibits the consummation of any 
of the transactions contemplated by this Agreement or the Registration Rights 
Agreement or the Debenture or the Warrants.

          (e)  OPINION OF COUNSEL.  At the Closing, the Investors shall have 
received an opinion of counsel to the Company in the form attached hereto as 
Exhibit 4.2(e) and such other opinions, certificates and documents as the 
Investors or their counsel shall reasonably require incident to the Closing.


                                      16
<PAGE>

          (f)  REGISTRATION RIGHTS AGREEMENT.  The Company and the Investors 
shall have executed and delivered the Registration Rights Agreement in the 
form and substance of Exhibit 4.2(f) attached hereto.

          (g)  ADVERSE CHANGES.  Since December 31, 1997, no event which had 
or is likely to have, in the reasonable judgment of the Investors, a Material 
Adverse Effect on the Company or any of its direct or indirect subsidiaries 
shall have occurred.

          (h)  OFFICER'S CERTIFICATE.  The Company shall have delivered to 
the Investors a certificate in form and substance satisfactory to the 
Investors and the Investors' Counsel, executed by an officer of the Company, 
certifying as to satisfaction of closing conditions, incumbency of signing 
officers, and the true, correct and complete nature of the Charter, By-Laws, 
good standing and authorizing resolutions of the Company.

          (i)  DEBENTURES AND WARRANTS.  The Investors shall have received 
certificates representing the Debentures and Warrants in the form and 
substance of Exhibit 1.1A and Exhibit 1.1B hereto.

          (j)  DUE DILIGENCE.  Each Investor shall have completed its 
financial, accounting, operational and legal due diligence in a manner 
satisfactory to such Investor in its sole discretion.

                                   ARTICLE 5

                                LEGEND AND STOCK

     The Company will issue one or more certificates representing the 
Debentures and the Warrants in the name of the Investor and in such 
denominations to be specified by the Investor prior to (or from time to time 
subsequent to) Closing. Each certificate representing the Debentures and the 
Warrants and any shares of Common Stock issued upon conversion or exercise 
thereof initially shall be stamped or otherwise imprinted with a legend 
substantially in the following form:

     THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 
1933 OR ANY STATE SECURITIES LAWS.  THEY MAY NOT BE SOLD OR OFFERED FOR SALE 
EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER SAID ACT AND ANY 
APPLICABLE STATE SECURITIES LAW OR AN APPLICABLE EXEMPTION FROM SUCH 
REGISTRATION REQUIREMENTS.

     The Company agrees to reissue Debentures and Warrants without the legend 
set forth above at such time as (i) the holder thereof is permitted to 
dispose of such Debentures and/or Warrants and Common Stock issuable upon 
conversion or exercise thereof pursuant to Rule 144(k) under the Act, or (ii) 
such Debentures and/or Warrants are sold to a purchaser or purchasers who (in 
the opinion of counsel to the seller or such purchaser(s), in form and 
substance reasonably satisfactory to the Company and its counsel) are able to 
dispose of such shares publicly without registration under the Act.


                                      17
<PAGE>

     Prior to the Registration Statement (as defined in the Registration 
Rights Agreement) being declared effective, any Common Shares issued pursuant 
to conversion of Debentures or Warrant Shares issued upon exercise of the 
Warrants shall bear a legend in the same form as the legend indicated above.  
Upon such Registration Statement becoming effective, the Company agrees to 
promptly, but no later than three (3) business days thereafter, issue new 
certificates representing such Common Shares and Warrant Shares without such 
legend.  Any Common Shares issued pursuant to conversion of Debentures or 
Warrant Shares issued upon exercise of the Warrants after the Registration 
Statement has become effective shall be free and clear of any legends, 
transfer restrictions and stop orders.  Notwithstanding the removal of such 
legend, each Investor agrees to sell the Common Shares and Warrant Shares 
represented by the new certificates in accordance with the applicable 
prospectus delivery requirements or in accordance with an exemption from the 
registration requirements of the Act.

     Nothing herein shall limit the right of any holder to pledge these 
securities pursuant to a bona fide margin account or lending arrangement.

                                   ARTICLE 6

                                  TERMINATION

     6.1  TERMINATION BY MUTUAL CONSENT.  This Agreement may be terminated at 
any time prior to the Closing by the mutual written consent of the Company 
and each of the Investors.

     6.2  OTHER TERMINATION.  This Agreement may be terminated by action of 
the Board of Directors of the Company or by any of the Investors at any time 
if the Closing shall not have been consummated by the fifth business day 
following the date of this Agreement; provided, however, that the party (or 
parties) prepared to close shall retain its (or their) right to sue for any 
breach by the other party (or parties).

                                   ARTICLE 7

                                 MISCELLANEOUS

     7.1  STAMP TAXES.  The Company shall pay all stamp and other taxes and 
duties levied in connection with the issuance of the Debentures pursuant 
hereto, the Common Shares issued upon conversion thereof, and the Warrant 
Shares issued upon exercise of the Warrants.

     7.2  SPECIFIC PERFORMANCE; CONSENT TO JURISDICTION; JURY TRIAL.

          (a)  The Company and the Investors acknowledge and agree that 
irreparable damage would occur in the event that any of the provisions of 
this Agreement were not performed in accordance with their specific terms or 
were otherwise breached.  It is accordingly agreed that the parties shall be 
entitled to an injunction or injunctions to prevent or cure breaches of the 
provisions of this Agreement and to enforce specifically the terms and 
provisions hereof, this being in addition to any other remedy to which any of 
them may be entitled by law or equity.


                                      18
<PAGE>

          (b)  THE COMPANY AND EACH OF THE INVESTORS (I) HEREBY IRREVOCABLY 
SUBMITS TO THE EXCLUSIVE JURISDICTION OF THE UNITED STATES DISTRICT COURT, 
THE NEW YORK STATE COURTS AND OTHER COURTS OF THE UNITED STATES SITTING IN 
NEW YORK COUNTY, NEW YORK FOR THE PURPOSES OF ANY SUIT, ACTION OR PROCEEDING 
ARISING OUT OF OR RELATING TO THIS AGREEMENT AND (II) HEREBY WAIVES, AND 
AGREES NOT TO ASSERT IN ANY SUCH SUIT ACTION OR PROCEEDING, ANY CLAIM THAT IT 
IS NOT PERSONALLY SUBJECT TO THE JURISDICTION OF SUCH COURT, THAT THE SUIT, 
ACTION OR PROCEEDING IS BROUGHT IN AN INCONVENIENT FORUM OR THAT THE VENUE OF 
THE SUIT, ACTION OR PROCEEDING IS IMPROPER.  THE COMPANY AND EACH OF THE 
INVESTORS CONSENTS TO PROCESS BEING SERVED IN ANY SUCH SUIT, ACTION OR 
PROCEEDING BY MAILING A COPY THEREOF TO SUCH PARTY AT THE ADDRESS IN EFFECT 
FOR NOTICES TO IT UNDER THIS AGREEMENT AND AGREES THAT SUCH SERVICE SHALL 
CONSTITUTE GOOD AND SUFFICIENT SERVICE OF PROCESS AND NOTICE THEREOF.  
NOTHING IN THIS PARAGRAPH SHALL AFFECT OR LIMIT ANY RIGHT TO SERVE PROCESS IN 
ANY OTHER MANNER PERMITTED BY APPLICABLE LAW.

          (c)  The Company and each Investor hereby waives all rights to a 
trial by jury.

     7.3  ENTIRE AGREEMENT; AMENDMENT.  This Agreement, together with the 
Registration Rights Agreement, the Warrants, the Debenture and the agreements 
and documents executed in connection herewith and therewith, contains the 
entire understanding of the parties with respect to the matters covered 
hereby and thereby and, except as specifically set forth herein or therein, 
neither the Company nor any Investor makes any representation, warranty, 
covenant or undertaking with respect to such matters.  No provision of this 
Agreement may be waived or amended other than by a written instrument signed 
by the party against whom enforcement of any such amendment or waiver is 
sought.

     7.4  NOTICES.  Any notice or other communication required or permitted 
to be given hereunder shall be in writing by mail, facsimile or personal 
delivery and shall be effective upon actual receipt of such notice.  The 
addresses for such communications shall be:

     to the Company:

     Zitel Corporation
     47211 Bayside Parkway
     Fremont, California  94538
     Attention:  Chief Financial Officer
     Facsimile:    (510) 440-8526


                                      19
<PAGE>

     with copies to:

     Cooley Godward LLP
     One Maritime Plaza
     20th Floor
     San Francisco, California  94111
     Attention:   John L. Cardoza, Esq.
     Facsimile: (415) 951-3699

     to the Investors:

     To each Investor at the address and/or fax number set
     forth on Schedule I of this Agreement.

     with copies to:

     Kleinberg, Kaplan, Wolff & Cohen, P.C.
     551 Fifth Avenue, 18th Floor
     New York, New York 10176
     Attention:   Stephen M. Schultz, Esq.
     Facsimile: (212) 986-8866

     Any party hereto may from time to time change its address for notices by 
giving at least 10 days' written notice of such changed address to the other 
parties hereto.

     7.5  INDEMNITY.  Each party shall indemnify each other party against any 
loss, cost or damages (including reasonable attorney's fees but excluding 
consequential damages) incurred as a result of such parties' breach of any 
representation, warranty, covenant or agreement in this Agreement.

     7.6  WAIVERS.  No waiver by any party of any default with respect to any 
provision, condition or requirement of this Agreement shall be deemed to be a 
continuing waiver in the future or a waiver of any other provision, condition 
or requirement hereof, nor shall any delay or omission of any party to 
exercise any right hereunder in any manner impair the exercise of any such 
right accruing to it thereafter.

     7.7  HEADINGS.  The headings herein are for convenience only, do not 
constitute a part of this Agreement and shall not be deemed to limit or 
affect any of the provisions hereof.

     7.8  SUCCESSORS AND ASSIGNS.  Except as otherwise provided herein, this 
Agreement shall be binding upon and inure to the benefit of the parties and 
their successors and permitted assigns.  The parties hereto may amend this 
Agreement without notice to or the consent of any third party.  The Company 
may not assign this Agreement or any rights or obligations hereunder without 
the prior written consent of all Investors, except that the Company may 
assign this Agreement in connection with a Change of Control Transaction 
occurring in excess of forty-five (45) days after the Effectiveness Date (as 
defined in the Debenture) (such 45 days to be extended one day for every day 
after that date on which there is not Effective Registration), so long as 
such assignment places the Investors in a position economically equivalent to 
that in which they 


                                      20
<PAGE>

would have been but for such assignment, in accordance with the terms of the 
Debentures and the Warrants.  Any Investor may assign this Agreement (in 
whole or in part) or any rights or obligations hereunder subject to the 
consent of the Company (such consent not to be unreasonably withheld) in 
connection with any sale or transfer of all or any portion of the Debentures 
or Warrants held by such Investor, provided that no consent of the Company 
will be required for any transfer or assignment by the Investor to (i) an 
affiliate or affiliates of the Investor or (ii) any person or entity whose 
investments are managed by an investment adviser that is the same as, or an 
affiliate of, the investment manager of the Investor.

     7.9  NO THIRD PARTY BENEFICIARIES.  This Agreement is intended for the 
benefit of the parties hereto and their respective permitted successors and 
assigns and is not for the benefit of, nor may any provision hereof be 
enforced by, any other person.

     7.10 GOVERNING LAW.  This Agreement shall be governed by and construed 
and enforced in accordance with the laws of the State of New York applicable 
to Agreements executed and to be performed entirely within such State.

     7.11 SURVIVAL.  The representations and warranties and the agreements 
and covenants of the Company and each Investor contained herein shall survive 
the Closing.

     7.12 EXECUTION.  This Agreement may be executed in two or more 
counterparts, all of which shall be considered one and the same agreement, it 
being understood that all parties need not sign the same counterpart.

     7.13 PUBLICITY.  The Company agrees that it will not disclose, and will 
not include in any public announcement, the name of any Investor without its 
consent, unless and until such disclosure is required by law or applicable 
regulation, and then only to the extent of such requirement.  The Company 
agrees that a copy of any public announcement regarding the matters covered 
by this Agreement or any agreement and document executed herewith and any 
public announcement (other than the filing of this Agreement as an exhibit on 
Form 8-K), including the name of an Investor will be approved by each 
Investor in advance of the release of such announcements.  The Company agrees 
that prior to the opening of trading on the day following the Closing Date, 
the Company shall issue a public announcement regarding the matters covered 
by this Agreement and related documents, which announcement shall be subject 
to the prior reasonable approval of the Investors.

     7.14 SEVERABILITY.  The parties acknowledge and agree that the Investors 
are not agents, affiliates or partners of each other, that all 
representations, warranties, covenants and agreements of the Investors 
hereunder are several and not joint, that no Investor shall have any 
responsibility or liability for the representations, warrants, agreements, 
acts or omissions of any other Investor, and that any rights granted to 
"Investors" hereunder shall be enforceable by each Investor hereunder.

     7.15 LIKE TREATMENT OF HOLDERS; REDEMPTION.  Neither the Company nor any 
of its affiliates shall, directly or indirectly, pay or cause to be paid any 
consideration (immediate or contingent), whether by way of interest, fee, 
payment for the redemption or conversion of Debentures or exercise of the 
Warrants, or otherwise, to any holder of Debentures or Warrants, 


                                      21
<PAGE>

for or as an inducement to, or in connection with the solicitation of, any 
consent, waiver or amendment of any terms or provisions of the Debenture or 
this Agreement or the Registration Rights Agreement or the Warrants, unless 
such consideration is required to be paid to all holders of Debentures and 
Warrants bound by such consent, waiver or amendment whether or not such 
holders so consent, waive or agree to amend and whether or not such holders 
tender their Debentures or Warrants for redemption, conversion or exercise.  
The Company shall not, directly or indirectly, redeem any Debentures unless 
such offer of redemption is made pro rata to all holders of Debentures on 
identical terms.

     7.16 NO STRICT CONSTRUCTION.  The language used in this Agreement will 
be deemed to be the language chosen by the parties to express their mutual 
intent, and no rules of strict construction will be applied against any party.

     7.17 MATRIDIGM TRANSACTION.  As used herein and in the Debentures and 
the Warrants the term "Matridigm Transaction" shall mean any transaction or 
series of transactions whereby the Company acquires additional debt or equity 
securities of Matridigm Corporation, a California corporation, or the 
business of the Company and Matridigm are combined and shall include, without 
limitation, the issuance for cash of shares of the Common Stock of the 
Company with a fair market value not to exceed $2,000,000, as determined as 
of the purchase date and pursuant to one-time reset provisions agreed to 
between the Company and the purchasers, with the proceeds used to procure the 
release of obligations of the purchasers to guarantee obligations of 
Matridigm.


                           [SIGNATURE PAGES FOLLOW]


                                      22
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be 
duly executed as of the date first above written.

                                    ZITEL CORPORATION

                                    By:       Anna M. McCann
                                        -----------------------------------
                                    Name:     Anna M. McCann
                                    Title:    V.P. Finance & Administration

                                    INVESTORS:

                                    HALIFAX FUND, L.P.

                                    By:       Jeffrey E. Devers
                                        -----------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President


                                    PALLADIN PARTNERS I, L.P.

                                    By:  PALLADIN GROUP L.P.
                                              Attorney-in-Fact

                                    By:       Jeffrey E. Devers
                                        -----------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President


                                    PALLADIN OVERSEAS FUND LIMITED

                                    By:  PALLADIN GROUP L.P.
                                              Attorney-in-Fact

                                    By:       Jeffrey E. Devers
                                        -----------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President


          [SIGNATURE PAGE TO ZITEL CORPORATION CONVERTIBLE SUBORDINATED
                         DEBENTURE PURCHASE AGREEMENT]


                                      23
<PAGE>

                                    THE GLENEAGLES FUND COMPANY

                                    By:  PALLADIN GROUP L.P.
                                              Attorney-in-Fact

                                    By:       Jeffrey E. Devers
                                        -----------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President

                                    PALLADIN SECURITIES, LLC

                                    By:       Jeffrey E. Devers
                                        -----------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President


                                    COLONIAL PENN LIFE INSURANCE COMPANY

                                    By:  PALLADIN GROUP L.P.
                                              Attorney-in-Fact

                                    By:       Jeffrey E. Devers
                                        -----------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President

                                    LANCER SECURITIES LIMITED

                                    By:  PALLADIN GROUP L.P.
                                              Attorney-in-Fact

                                    By:       Jeffrey E. Devers
                                        -----------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President



          [SIGNATURE PAGE TO ZITEL CORPORATION CONVERTIBLE SUBORDINATED
                         DEBENTURE PURCHASE AGREEMENT]


                                      24


<PAGE>
                                     
                                 EXHIBIT 4.3

                        REGISTRATION RIGHTS AGREEMENT

     THIS REGISTRATION RIGHTS AGREEMENT ("Agreement") is entered into as of 
February 2, 1999 between ZITEL CORPORATION, a California corporation with 
offices at 47211 Bayside Parkway, Fremont, California  94538 (the "Company") 
and each of the entities listed under "Investors" on the signature page 
hereto (each an "Investor" and collectively the "Investors"), each with 
offices at the address listed under such Investor's name on Schedule I hereto.

                                 WITNESSETH:

     WHEREAS, pursuant to that certain Convertible Subordinated Debenture 
Purchase Agreement by and between the Company and the Investors (the 
"Purchase Agreement"), the Company initially has agreed to sell and issue to 
the Investors, and the Investors have agreed to purchase from the Company, an 
aggregate of $5 million principal amount of the Company's 3% Convertible 
Subordinated Debentures (the "Debentures") on the terms and conditions set 
forth therein;

     WHEREAS, the Purchase Agreement contemplates that the Debentures will be 
convertible into shares (the "Common Shares") of common stock, no par value, 
of the Company ("Common Stock") pursuant to the terms and conditions set 
forth in the Debentures; and

     WHEREAS, pursuant to the terms of, and in partial consideration for, the 
Investors' agreement to enter into the Purchase Agreement, the Company has 
agreed to issue the Warrants exercisable for Warrant Shares and to provide 
the Investors with certain registration rights with respect to the Common 
Shares and Warrant Shares and certain other rights and remedies with respect 
to the Debentures as set forth in this Agreement;

     NOW, THEREFORE, in consideration of the mutual promises, 
representations, warranties, covenants and conditions set forth in the 
Purchase Agreement and this Agreement, the Company and the Investors agree as 
follows:

     1.   CERTAIN DEFINITIONS.  Capitalized terms used herein and not 
otherwise defined shall have the meaning ascribed thereto in the Purchase 
Agreement, Warrants or the Debentures.  As used in this Agreement, the 
following terms shall have the following respective meanings:

     "CLOSING" and "CLOSING DATE" shall have the meanings ascribed to such 
terms in the Purchase Agreement.

     "COMMISSION" or "SEC" shall mean the Securities and Exchange Commission 
or any other federal agency at the time administering the Securities Act.

     "OUTSTANDING PRINCIPAL AMOUNT" shall have the meaning ascribed to such 
term in the Debentures.

                                     1
<PAGE>

     "REGISTRABLE SECURITIES" shall mean:  (i) the Common Shares and Warrants 
Shares issued to each Holder or its permitted transferee or designee upon 
conversion of the Debentures or exercise of the Warrants, as applicable, or 
upon any stock split, stock dividend, recapitalization or similar event with 
respect to such Common Shares or Warrant Shares; (ii) any securities issued 
or issuable to each Holder upon the conversion, exercise or exchange of any 
Debentures, Warrants, Warrant Shares, or Common Shares; and (iii) any other 
security of the Company issued as a dividend or other distribution with 
respect to, conversion or exchange of or in replacement of Registrable 
Securities.

     The terms "REGISTER", "REGISTERED" and "REGISTRATION" shall refer to a 
registration effected by preparing and filing a registration statement in 
compliance with the Securities Act and applicable rules and regulations 
thereunder, and the declaration or ordering of the effectiveness of such 
registration statement.

     "REGISTRATION EXPENSES" shall mean all expenses to be incurred by the 
Company in connection with each Holder's registration rights under this 
Agreement, including, without limitation, all registration and filing fees, 
printing expenses, fees and disbursements of counsel for the Company, blue 
sky fees and expenses, reasonable fees and disbursements of counsel to 
Holders (using a single counsel selected by a majority in interest of the 
Holders) for a "due diligence" examination of the Company and review of the 
Registration Statement and related documents, and the expense of any special 
audits incident to or required by any such registration (but excluding the 
compensation of regular employees of the Company, which shall be paid in any 
event by the Company).

     "SELLING EXPENSES" shall mean all underwriting discounts and selling 
commissions applicable to the sale of Registrable Securities and all fees and 
disbursements of counsel for Holders not included within "Registration 
Expenses".

     "HOLDER" and "HOLDERS" shall include an Investor or the Investors, 
respectively, and any transferee of the Debentures, Warrants, Warrant Shares 
or Common Shares or Registrable Securities which have not been sold to the 
public to whom the registration rights conferred by this Agreement have been 
transferred in compliance with this Agreement.

     "REGISTRATION STATEMENT" shall have the meaning set forth in Section 
2(a) herein.

     "REGULATION D" shall mean Regulation D as promulgated pursuant to the 
Securities Act, and as subsequently amended.

     "SECURITIES ACT" or "ACT" shall mean the Securities Act of 1933, as 
amended.

     "WARRANTS" shall mean the warrants in form and substance of Exhibit 1.1B 
to the Purchase Agreement between the Company and the Investors, dated as of 
the date hereof.

     "WARRANT SHARES" shall mean shares of Common Stock of the Company issued 
and issuable upon exercise of the Warrant.

     2.   REGISTRATION REQUIREMENTS.  The Company shall use its best efforts to
effect the registration of the Registrable Securities (including without
limitation the execution of an 

                                     2
<PAGE>

undertaking to file post-effective amendments, appropriate qualification 
under applicable blue sky or other state securities laws and appropriate 
compliance with applicable regulations issued under the Securities Act) as 
would permit or facilitate the sale or distribution of all the Registrable 
Securities in the manner (including manner of sale) and in all states 
reasonably requested by the Holder.  Such best efforts by the Company shall 
include the following:

          (a)  The Company shall, as expeditiously as reasonably possible 
after the Closing Date:

               (i)   But in any event within 30 days thereafter, prepare and 
file a registration statement with the Commission pursuant to Rule 415 under 
the Securities Act on Form S-3 under the Securities Act (or in the event that 
the Company is ineligible to use such form, such other form as the Company is 
eligible to use under the Securities Act) covering the Registrable Securities 
("Registration Statement").  Such Registration Statement shall, in addition 
and without limitation, register (pursuant to Rule 416 under the Securities 
Act, or otherwise) such additional indeterminate number of Registrable 
Securities as shall be necessary to permit the conversion in full of the 
Debentures and the issuance of additional shares of Common Stock to Holders 
pursuant to the various reset provisions of the Debentures.  Thereafter, the 
Company shall use its best efforts to cause such Registration Statement and 
other filings to be declared effective as soon as possible, and in any event 
prior to 90 days following the Closing Date.  The Company shall provide 
Holders and their legal counsel reasonable opportunity to review any such 
Registration Statement or amendment or supplement thereto prior to filing.

               (ii)  Prepare and file with the SEC such amendments and 
supplements to such Registration Statement and the prospectus used in 
connection with such Registration Statement as may be necessary to comply 
with the provisions of the Act with respect to the disposition of all 
securities covered by such Registration Statement and notify the Holders of 
the filing and effectiveness of such Registration Statement and any 
amendments or supplements.

               (iii) Furnish to each Holder such numbers of copies of a 
current prospectus conforming with the requirements of the Act, copies of the 
Registration Statement, any amendment or supplement thereto and any documents 
incorporated by reference therein and such other documents as such Holder may 
reasonably require in order to facilitate the disposition of Registrable 
Securities owned by such Holder.

               (iv)  Use its best efforts to register and qualify the 
securities covered by such Registration Statement under such other securities 
or "Blue Sky" laws of such jurisdictions as shall be reasonably requested by 
each Holder; provided that the Company shall not be required in connection 
therewith or as a condition thereto to qualify to do business or to file a 
general consent to service of process in any such states or jurisdictions.

               (v)   Notify each Holder immediately of the happening of any 
event as a result of which the prospectus (including any supplements thereto 
or thereof) included in such Registration Statement, as then in effect, 
includes an untrue statement of material fact or omits to state a material 
fact required to be stated therein or necessary to make the statements 
therein not misleading in light of the circumstances then existing, and use 
its best efforts to promptly update and/or correct such prospectus.

                                     3
<PAGE>

               (vi)  Notify each Holder immediately of the issuance by the 
Commission or any state securities commission or agency of any stop order 
suspending the effectiveness of the Registration Statement or the initiation 
of any proceedings for that purpose.  The Company shall use its best efforts 
to prevent the issuance of any stop order and, if any stop order is issued, 
to obtain the lifting thereof at the earliest possible time.

               (vii) Permit a single firm of counsel, designated as Holders' 
counsel by a majority of the Registrable Securities included in the 
Registration Statement, to review the Registration Statement and all 
amendments and supplements thereto within a reasonable period of time prior 
to each filing, and shall not file any document in a form to which such 
counsel reasonably objects.

               (viii) Use its best efforts to list the Registrable Securities 
covered by such Registration Statement with all securities exchange(s) and/or 
markets on which the Common Stock is then listed and prepare and file any 
required filings with the National Association of Securities Dealers, Inc. or 
any exchange or market where the Common Shares are traded.

               (ix)  Take all steps necessary to enable Holders to avail 
themselves of the prospectus delivery mechanism set forth in Rule 153 (or 
successor thereto) under the Act.

          (b)  Set forth below in this Section 2(b) are (I) events that may 
arise that the Investors consider will interfere with the full enjoyment of 
their rights under the Debentures, the Purchase Agreement and this Agreement 
(the "Interfering Events"), and (II) certain remedies applicable in each of 
these events.  Paragraphs (i) through (iv) of this Section 2(b) describe the 
Interfering Events, provide a remedy to the Investors if an Interfering Event 
occurs and provide that the Investors may require that the Company redeem 
outstanding Debentures at a specified price if certain Interfering Events are 
not timely cured.  Paragraph (v) provides, inter alia, that if cash payments 
required as the remedy in the case of certain of the Interfering Events are 
not paid when due, the Company may be required by the Investors to redeem 
outstanding Debentures at a specified price.  Paragraph (vi) provides, inter 
alia, that the Investors have the right to specific performance.  The 
preceding paragraphs in this Section 2(b) are meant to serve only as an 
introduction to this Section 2(b), are for convenience only, and are not to 
be considered in applying, construing or interpreting this Section 2(b).

               (i)   DELAY IN EFFECTIVENESS OF REGISTRATION STATEMENT.  The 
Company agrees that it shall file the Registration Statement complying with 
the requirements of this Agreement promptly and in any event within 30 days 
following the date of the initial closing of the Purchase Agreement (the 
"Closing Date") and shall use its best efforts to cause such Registration 
Statement to become effective as soon as possible and in any event within 90 
days from the Closing Date.  In the event that such Registration Statement 
has not been declared effective within 90 days from the Closing Date, then 
the percentage (initially 90%) employed to determine the "Conversion Price" 
pursuant to Section 5(c) of the Debentures and all Conversion Price resets 
pursuant to Sections 5(d) and 5(e) of the Debentures (the "Agreed 
Percentage") shall be reduced by 1% during and after the 30-day period 
("Default Period") from and after the 90th day following the Closing Date 
during any part of which such Registration Statement is not effective, and 
such Agreed Percentage shall be further reduced by an additional 1.5% during 
and 

                                     4
<PAGE>

after each Default Period thereafter.  For example, if the Registration 
Statement does not become effective until 120 days from the Closing Date, the 
Agreed Percentage from and after day 91 shall be equal to 89%.  If the 
Registration Statement is not effective until the 150th day after the Closing 
Date, the Agreed Percentage from and after day 121 from the Closing Date 
shall be 87.5%.  In each case, the Agreed Percentage and the Conversion Price 
shall be subject to further adjustment as set forth in the Debenture and the 
Purchase Agreement.  If the Registration Statement has not been declared 
effective within 150 days after the Closing Date, then each Holder shall have 
the right in its sole discretion to sell its Debentures, Common Shares and/or 
Warrant Shares to the Company (in whole or in part) at a price in immediately 
available funds (the "Premium Redemption Price") equal to (A) as to the 
Debentures, 1.3 times (i.e., 130% of) the Outstanding Principal Amount of the 
Debentures plus any accrued but unpaid or unrecognized interest or default 
payments and (B) as to the Common Shares and/or Warrant Shares, 1.3 times the 
dollar amount which is the product of (x) the number of shares so to be 
redeemed pursuant to this paragraph, and (y) the fair market value of such 
shares (as defined in the Debentures) at the time such shares were received 
pursuant to conversion of Debentures or exercise of Warrants.  Payment of 
such amount shall be due and payable within 3 business days of demand 
therefor, which demand shall be revocable by the Holder at any time prior to 
its actual receipt of the Premium Redemption Price.

               (ii)  NO LISTING; PREMIUM PRICE REDEMPTION FOR DELISTING OF 
CLASS OF SHARES.

                    (A)  In the event that the Company fails, refuses or is 
unable to cause the Registrable Securities covered by the Registration 
Statement to be listed with the Approved Market and each other securities 
exchange and market on which the Common Stock is then traded at all times 
during the period ("Listing Period") commencing the earlier of the effective 
date of the Registration Statement or the 90th day following the Closing 
Date, and continuing thereafter for so long as the Debentures are 
outstanding, then the Company shall pay in cash to each Holder a default 
payment at a rate (the "Default Payment Rate") equal to two percent (2%) of 
the sum of (x) the Outstanding Principal Amount of, (y) the accrued but 
unpaid interest on, plus (z) the accrued but unpaid or unrecognized default 
payments on the Debentures (the "Debenture Amount") held by such Holder for 
each 30-day period (or portion thereof) during the Listing Period from and 
after such failure, refusal or inability to so list the Registrable 
Securities until the Registrable Securities are so listed.

                    (B)  In the event that shares of Common Stock of the 
Company are delisted from the Approved Market at any time following the 
Closing Date and remain delisted for 5 consecutive days, then at the option 
of each Holder and to the extent such Holder so elects, the Company shall on 
2 business days notice redeem the Debentures and/or Common Shares and/or 
Warrant Shares held by such Holder, in whole or in part, at a redemption 
price equal to the Premium Redemption Price (as defined above); provided, 
however, that such Holder may revoke such request at any time prior to 
receipt of such payment of such redemption price.  Default payments shall no 
longer accrue on Debentures after such shares have been redeemed by the 
Company pursuant to the foregoing provision.

               (iii) BLACKOUT PERIODS.  In the event any Holder's ability to 
sell Registrable Securities under the Registration Statement is suspended:

                                     5
<PAGE>

                    (A)  for more than (i) five (5) consecutive days or (ii) 
ten (10) days in any calendar year ("Suspension Grace Period"), including 
without limitation by reason of a suspension of trading of the Common Stock 
on the Approved Market, any suspension or stop order with respect to the 
Registration Statement or the fact that an event has occurred as a result of 
which the prospectus (including any supplements thereto) included in such 
Registration Statement then in effect includes an untrue statement of 
material fact or omits to state a material fact required to be stated therein 
or necessary to make the statements therein not misleading in light of the 
circumstances then existing; or

                    (B)  for more than (i) twenty (20) consecutive days or 
(ii) thirty (30) days in any calendar year ("Corporate Event Suspension Grace 
Period"), by reason of any corporate event, including, without limitation, a 
merger, acquisition or disposition;

then the Company shall pay in cash to each Holder a default payment at the 
Default Payment Rate of the Debenture Amount for the Debentures held by such 
Holder for each 30-day period (or portion thereof) from and after the 
expiration of the Suspension Grace Period or Corporate Event Suspension Grace 
Period. Alternatively, a Holder shall have the right but not the obligation 
to have the Company redeem its Debentures and Common Shares and Warrant 
Shares at the price and on the terms (and subject to the right to revoke) set 
forth in Section 2(b)(i) above.

               (iv)  CONVERSION DEFICIENCY; PREMIUM PRICE REDEMPTION FOR 
CONVERSION DEFICIENCY.  In the event that the Company does not have a 
sufficient number of Common Shares available to satisfy the Company's 
obligations to any Holder upon receipt of a Conversion Notice (as defined in 
the Debenture) or is otherwise unable or unwilling to issue such Common 
Shares (including without limitation by reason of the limit described in 
Section 10 below) in accordance with the terms of the Debenture for any 
reason after receipt of a Conversion Notice, then:

                    (A)  The Company shall pay in cash to each Holder a 
default payment at the Default Payment Rate on the Debenture Amount for the 
Debentures held by such Holder for each 30-day period (or portion thereof) 
that the Company fails or refuses to issue Common Shares in accordance with 
the Debenture terms; and

                    (B)  At any time five days after the commencement of the 
running of the first 30-day period described above in clause (A) of this 
paragraph (iv), at the request of any Holder pursuant to a redemption notice, 
the Company promptly (1) shall purchase from such Holder, at a purchase price 
equal to the Premium Redemption Price, the Debenture Amount of Debentures 
equal to such Holder's pro rata share of the "Deficiency", as such terms are 
defined below, if the failure to issue Common Shares results from the lack of 
a sufficient number thereof and (2) shall purchase all (or such portion as 
such Holder may elect) of such Holder's Debentures at such Premium Redemption 
Price if the failure to issue Common Shares results from any other cause.  
The "Deficiency" shall be equal to the Debenture Amount of Debentures that 
would not be able to be converted for Common Shares, due to an insufficient 
number of Common Shares available, if all the outstanding Debentures were 
submitted for conversion at the Conversion Price set forth in the Debentures 
as of the date such Deficiency is determined.  Any request by a Holder 
pursuant to this paragraph (iv)(B) shall be revocable by that Holder at any 
time prior to its receipt of the Premium Redemption Price.

                                     6
<PAGE>

               (v)   PREMIUM PRICE REDEMPTION FOR CASH PAYMENT DEFAULTS.

                    (A)  The Company acknowledges that any failure, refusal 
or inability by the Company described in the foregoing paragraphs (i) through 
(iv) will cause the Holders to suffer damages in an amount that will be 
difficult to ascertain, including without limitation damages resulting from 
the loss of liquidity in the Registrable Securities and the additional 
investment risk in holding the Registrable Securities.  Accordingly, the 
parties agree that it is appropriate to include in this Agreement the 
foregoing provisions for default payments, discounts and mandatory 
redemptions in order to compensate the Holders for such damages.  The parties 
acknowledge and agree that the default payments, discounts and mandatory 
redemptions set forth above represent the parties' good faith effort to 
quantify such damages and, as such, agree that the form and amount of such 
default payments, discounts and mandatory redemptions are reasonable and will 
not constitute a penalty.

                    (B)  Each default payment provided for in the foregoing 
paragraphs (ii) through (iv) shall be in addition to each other default 
payment; provided, however, that in no event shall the Company be obligated 
to pay to any Holder default payments in an aggregate amount greater than the 
Default Payment Rate of the Debenture Amount of the Debentures held by such 
Holder for any 30-day period (or portion thereof).  All default payments 
(which payments shall be pro rata on a per diem basis for any period of less 
than 30 days) required to be made in connection with the above provisions 
shall be paid in cash at any time upon demand, and whether or not a demand is 
made, by the tenth (10th) day of each calendar month for each partial or full 
30-day period occurring prior to that date.  Until paid as required in this 
Agreement, default payments shall be deemed added to, and a part of, the 
Outstanding Principal Amount of a Holder's Debentures.

                    (C)  In the event that the Company fails or refuses to 
pay any default payment or honor any default adjustments of the Agreed 
Percentage when due, at any Holder's request and option the Company shall 
purchase all or a portion of the Debentures, Common Shares and/or Warrant 
Shares held by such Holder (with default payments accruing through the date 
of such purchase), within five (5) days of such request, at a purchase price 
equal to the Premium Redemption Price (as defined above), provided that such 
Holder may revoke such request at any time prior to receipt of such payment 
of such purchase price. Until such time as the Company purchases such 
Debentures at the request of such Holder pursuant to the preceding sentence, 
at any Holder's request and option the Company shall as to such Holder pay 
such amount by adding and including the amount of such default payment to the 
Outstanding Principal Amount of a Holder's Debentures.

               (vi)  CUMULATIVE REMEDIES.  The default payments and mandatory 
redemptions provided for above are in addition to and not in lieu or 
limitation of any other rights the Holders may have at law, in equity or 
under the terms of the Debentures, the Purchase Agreement, the Warrants or 
this Agreement, including without limitation the right to specific 
performance.  Each Holder shall be entitled to specific performance of any 
and all obligations of the Company in connection with the registration rights 
of the Holders hereunder.

          (c)  If the Holder(s) intend to distribute the Registrable 
Securities by means of an underwriting, the Holder(s) shall so advise the 
Company.  Any such underwriting may only 

                                     7
<PAGE>

be administered by investment bankers reasonably satisfactory to the Company. 
 The Company shall only be obligated to permit one underwritten offering, 
which offering shall be determined by a majority-in-interest of the Holders.

          (d)  The Company shall enter into such customary agreements for 
secondary offerings (including a customary underwriting agreement with the 
underwriter or underwriters, if any) and take all such other reasonable 
actions reasonably requested by the Holders in connection therewith in order 
to expedite or facilitate the disposition of such Registrable Securities.  
When Registrable Securities are to be sold in an underwritten offering the 
Company shall:

               (i)   make such representations and warranties to the Holders 
and the underwriter or underwriters, if any, in form, substance and scope as 
are customarily made by issuers to underwriters and holders in secondary 
offerings;

               (ii)  cause to be delivered to the sellers of Registrable 
Securities and the underwriter or underwriters, if any, opinions of 
independent counsel to the Company, on and dated as of the Effectiveness 
Date, which counsel and opinions (in form, scope and substance) shall be 
reasonably satisfactory to the Holders and the underwriter(s), if any, and 
their counsel and covering, without limitation, such matters as are 
customarily given to underwriters and holders in underwritten offerings, 
addressed to the Holders and each underwriter, if any;

               (iii) cause to be delivered, immediately prior to the 
effectiveness of the Registration Statement (and at the time of delivery of 
any Registrable Securities sold pursuant thereto), a "comfort" letter from 
the Company's independent certified public accountants addressed to the 
Holders and each underwriter, if any, stating that such accountants are 
independent public accountants within the meaning of the Securities Act and 
the applicable published rules and regulations thereunder, and otherwise in 
customary form and covering such financial and accounting matters as are 
customarily covered by letters of the independent certified public 
accountants delivered in connection with registered offerings;

               (iv)  the underwriting agreement shall include customary 
indemnification and contribution provisions to and from the underwriters and 
procedures for secondary underwritten offerings; and

               (v)   deliver such documents and certificates as may be 
reasonably requested by the Holders of the Registrable Securities being sold 
or the managing underwriter or underwriters, if any, to evidence compliance 
with clause (i) above and with any customary conditions contained in the 
underwriting agreement, if any.

          (e)  The Company shall make available for inspection by the 
Holders, representative(s) of all the Holders together, any underwriter 
participating in any disposition pursuant to a Registration Statement, and 
any attorney or accountant retained by any Holder or underwriter, all 
financial and other records customary for purposes of the Holders' due 
diligence examination of the Company and review of any Registration 
Statement, all SEC Documents (as defined in the Purchase Agreement) filed 
subsequent to the Closing, pertinent corporate documents and properties of 
the Company, and cause the Company's officers, directors and 

                                     8
<PAGE>

employees to supply all information reasonably requested by any such 
representative, underwriter, attorney or accountant in connection with such 
Registration Statement, provided that such parties agree to keep such 
information confidential.

          (f)  Subject to Section 2(b) above, the Company may suspend the use 
of any prospectus used in connection with the Registration Statement only in 
the event, and for such period of time as, such a suspension is required by 
the rules and regulations of the Commission.  The Company will use its best 
efforts to cause such suspension to terminate at the earliest possible date.

          (g)  The Company shall file a Registration Statement with respect 
to any newly authorized and/or reserved shares within five (5) business days 
of any shareholders meeting authorizing same and shall use its best efforts 
to cause such Registration Statement to become effective within sixty (60) 
days of such shareholders meeting.  If the Holders become entitled, pursuant 
to an event described in clause (iii) of the definition of Registrable 
Securities, to receive any securities in respect of Registrable Securities 
that were already included in a Registration Statement, subsequent to the 
date such Registration Statement is declared effective, and the Company is 
unable under the securities laws to add such securities to the then effective 
Registration Statement, the Company shall promptly file, in accordance with 
the procedures set forth herein, an additional Registration Statement with 
respect to such newly Registrable Securities.  The Company shall use its best 
efforts to (i) cause any such additional Registration Statement, when filed, 
to become effective under the Securities Act, and (ii) keep such additional 
Registration Statement effective during the period described in Section 5 
below.  All of the registration rights and remedies under this Agreement 
shall apply to the registration of such newly reserved shares and such new 
Registrable Securities, including without limitation the provisions providing 
for default payments contained herein.

     3.   EXPENSES OF REGISTRATION.  All Registration Expenses incurred in 
connection with any registration, qualification or compliance with 
registration pursuant to this Agreement shall be borne by the Company, and 
all Selling Expenses of a Holder shall be borne by such Holder.

     4.   REGISTRATION ON FORM S-3.  The Company shall use its best efforts 
to qualify for registration on Form S-3 or any comparable or successor form 
or forms, or in the event that the Company is ineligible to use such form, 
such form as the Company is eligible to use under the Securities Act.

     5.   REGISTRATION PERIOD.  In the case of the registration effected by 
the Company pursuant to this Agreement, the Company will use its best efforts 
to keep such registration effective until the later of (a) the first 
anniversary of the issue of the Debenture and Warrant and (b) the date upon 
which all shares of Common Stock issuable upon conversion of the Debentures 
have been sold freely without restriction.

     6.   INDEMNIFICATION.

          (a)  THE COMPANY INDEMNITY.  The Company will indemnify each Holder,
each of its officers, directors and partners, and each person controlling each
Holder, within the 

                                     9
<PAGE>

meaning of Section 15 of the Securities Act and the rules and regulations 
thereunder with respect to which registration, qualification or compliance 
has been effected pursuant to this Agreement, and each underwriter, if any, 
and each person who controls, within the meaning of Section 15 of the 
Securities Act and the rules and regulations thereunder, any underwriter, 
against all claims, losses, damages and liabilities (or actions in respect 
thereof) arising out of or based on any untrue statement (or alleged untrue 
statement) of a material fact contained in any prospectus, offering circular 
or other document (including any related registration statement, notification 
or the like) incident to any such registration, qualification or compliance, 
or based on any omission (or alleged omission) to state therein a material 
fact required to be stated therein or necessary to make the statements 
therein not misleading, or any violation by the Company of the Securities Act 
or any state securities law or in either case, any rule or regulation 
thereunder applicable to the Company and relating to action or inaction 
required of the Company in connection with any such registration, 
qualification or compliance, and will reimburse each Holder, each of its 
officers, directors and partners, and each person controlling such Holder, 
each such underwriter and each person who controls any such underwriter, for 
any legal and any other expenses reasonably incurred in connection with 
investigating and defending any such claim, loss, damage, liability or 
action, provided that the Company will not be liable in any such case to a 
Holder to the extent that any such claim, loss, damage, liability or expense 
arises out of or is based on any untrue statement or omission based upon 
written information furnished to the Company by such Holder or the 
underwriter (if any) therefor and stated to be specifically for se therein.  
The indemnity agreement contained in this Section 6(a) shall not apply to 
amounts paid in settlement of any such loss, claim, damage, liability or 
action if such settlement is effected without the consent of the Company 
(which consent will not be unreasonably withheld).

          (b)  HOLDER INDEMNITY.  Each Holder will, severally and not 
jointly, if Registrable Securities held by it are included in the securities 
as to which such registration, qualification or compliance is being effected, 
indemnify the Company, each of its directors, officers, partners, and each 
underwriter, if any, of the Company's securities covered by such a 
registration statement, each person who controls the Company or such 
underwriter within the meaning of Section 15 of the Securities Act and the 
rules and regulations thereunder, each other Holder (if any), and each of 
their officers, directors and partners, and each person controlling such 
other Holder(s) against all claims, losses, damages and liabilities (or 
actions in respect thereof) arising out of or based on any untrue statement 
(or alleged untrue statement) of a material fact contained in any such 
registration statement, prospectus, offering circular or other document, or 
any omission (or alleged omission) to state therein a material fact required 
to be stated therein or necessary to make the statement therein not 
misleading, and will reimburse the Company and such other Holder(s) and their 
directors, officers and partners, underwriters or control persons for any 
legal or any other expenses reasonably incurred in connection with 
investigating and defending any such claim, loss, damage, liability or 
action, in each case to the extent, but only to the extent, that such untrue 
statement (or alleged untrue statement) or omission (or alleged omission) is 
made in such registration statement, prospectus, offering circular or other 
document in reliance upon and in conformity with written information 
furnished to the Company by such Holder and stated to be specifically for use 
therein, and provided that the maximum amount for which such Holder shall be 
liable under this indemnity shall not exceed the net proceeds received by 
such Holder from the sale of the Registrable Securities.  The indemnity 
agreement contained in this Section 6(b) shall not apply to amounts paid in 
settlement 

                                     10
<PAGE>

of any such claims, losses, damages or liabilities if such settlement is 
effected without the consent of such Holder (which consent shall not be 
unreasonably withheld).

          (c)  PROCEDURE.  Each party entitled to indemnification under this 
Article (the "Indemnified Party") shall give notice to the party required to 
provide indemnification (the "Indemnifying Party") promptly after such 
Indemnified Party has actual knowledge of any claim as to which indemnity may 
be sought, and shall permit the Indemnifying Party to assume the defense of 
any such claim in any litigation resulting therefrom, provided that counsel 
for the Indemnifying Party, who shall conduct the defense of such claim or 
any litigation resulting therefrom, shall be approved by the Indemnified 
Party (whose approval shall not be unreasonably withheld), and the 
Indemnified Party may participate in such defense at such party's expense, 
and provided further that the failure of any Indemnified Party to give notice 
as provided herein shall not relieve the Indemnifying Party of its 
obligations under this Article except to the extent that the Indemnifying 
Party is materially and adversely affected by such failure to provide notice. 
 No Indemnifying Party, in the defense of any such claim or litigation, 
shall, except with the consent of each Indemnified Party, consent to entry of 
any judgment or enter into any settlement which does not include as an 
unconditional term thereof the giving by the claimant or plaintiff to such 
Indemnified Party of a release from all liability in respect to such claim or 
litigation.  Each Indemnified Party shall furnish such information regarding 
itself or the claim in question as an Indemnifying Party may reasonably 
request in writing and as shall be reasonably required in connection with the 
defense of such claim and litigation resulting therefrom.

     7.   CONTRIBUTION.  If the indemnification provided for in Section 6 
herein is unavailable to the Indemnified Parties in respect of any losses, 
claims, damages or liabilities referred to herein (other than by reason of 
the exceptions provided therein), then each such Indemnifying Party, in lieu 
of indemnifying such Indemnified Party, shall contribute to the amount paid 
or payable by such Indemnified Party as a result of such losses, claims, 
damages or liabilities as between the Company on the one hand and any Holder 
on the other, in such proportion as is appropriate to reflect the relative 
fault of the Company and of such Holder in connection with the statements or 
omissions which resulted in such losses, claims, damages or liabilities, as 
well as any other relevant equitable considerations.  The relative fault of 
the Company on the one hand and of any Holder on the other shall be 
determined by reference to, among other things, whether the untrue or alleged 
untrue statement of a material fact or omission or alleged omission to state 
a material fact relates to information supplied by the Company or by such 
Holder.

     In no event shall the obligation of any Indemnifying Party to contribute 
under this Section 7 exceed the amount that such Indemnifying Party would 
have been obligated to pay by way of indemnification if the indemnification 
provided for under Section 6(a) or 6(b) hereof had been available under the 
circumstances.

     The Company and the Holders agree that it would not be just and equitable
if contribution pursuant to this Section 7 were determined by pro rata
allocation (even if the Holders or the underwriters were treated as one entity
for such purpose) or by any other method of allocation which does not take
account of the equitable considerations referred to in the immediately preceding
paragraphs.  The amount paid or payable by an Indemnified Party as a 

                                     11
<PAGE>

result of the losses, claims, damages and liabilities referred to in the 
immediately preceding paragraphs shall be deemed to include, subject to the 
limitations set forth above, any legal or other expenses reasonably incurred 
by such Indemnified Party in connection with investigating or defending any 
such action or claim. Notwithstanding the provisions of this section, no 
Holder or underwriter shall be required to contribute any amount in excess of 
the amount by which (i) in the case of any Holder, the net proceeds received 
by such Holder from the sale of Registrable Securities or (ii) in the case of 
an underwriter, the total price at which the Registrable Securities purchased 
by it and distributed to the public were offered to the public exceeds, in 
any such case, the amount of any damages that such Holder or underwriter has 
otherwise been required to pay by reason of such untrue or alleged untrue 
statement or omission or alleged omission.  No person guilty of fraudulent 
misrepresentation (within the meaning of Section 11(f) of the Securities Act) 
shall be entitled to contribution from any person who was not guilty of such 
fraudulent misrepresentation.

     8.   SURVIVAL.  The indemnity and contribution agreements contained in 
Sections 6 and 7 and the representations and warranties of the Company 
referred to in Section 2(d)(i) shall remain operative and in full force and 
effect regardless of (i) any termination of this Agreement or the Purchase 
Agreement or any underwriting agreement, (ii) any investigation made by or on 
behalf of any Indemnified Party or by or on behalf of the Company, and (iii) 
the consummation of the sale or successive resales of the Registrable 
Securities.

     9.   INFORMATION BY HOLDERS.  Each Holder shall furnish to the Company 
such information regarding such Holder and the distribution and/or sale 
proposed by such Holder as the Company may reasonably request in writing and 
as shall be reasonably required in connection with any registration, 
qualification or compliance referred to in this Agreement.  The intended 
method or methods of disposition and/or sale (Plan of Distribution) of such 
securities as so provided by such Investor shall be included without 
alteration in the Registration Statement covering the Registrable Securities 
and shall not be changed without written consent of such Holder.

     10.  NASDAQ LIMIT ON STOCK ISSUANCES.  Section 7(g) of the Debenture 
shall govern limits imposed by NASDAQ rules on the conversion of Debentures 
or the exercise of Warrants.

     11.  REPLACEMENT CERTIFICATES.  The certificate(s) representing the 
Common Shares or Warrant Shares held by any Investor (or then Holder) may be 
exchanged by such Investor (or such Holder) at any time and from time to time 
for certificates with different denominations representing an equal aggregate 
number of Common Shares or Warrant Shares, as reasonably requested by such 
Investor (or such Holder) upon surrendering the same.  No service charge will 
be made for such registration or transfer or exchange.

     12.  TRANSFER OR ASSIGNMENT.  Except as otherwise provided herein, this 
Agreement shall be binding upon and inure to the benefit of the parties and 
their successors and permitted assigns.  The rights granted to the Investors 
by the Company under this Agreement to cause the Company to register 
Registrable Securities may be transferred or assigned (in whole or in part) 
to a transferee or assignee of Debentures or Warrants, and all other rights 
granted to the Investors by the Company hereunder may be transferred or 
assigned to any transferee or assignee of any Debentures or Warrants; 
provided in each case that the Company must be given written notice by 

                                     12
<PAGE>

the such Investor at the time of or within a reasonable time after said 
transfer or assignment, stating the name and address of said transferee or 
assignee and identifying the securities with respect to which such 
registration rights are being transferred or assigned; and provided further 
that the transferee or assignee of such rights agrees in writing to be bound 
by the registration provisions of this Agreement.

     13.  MISCELLANEOUS.

          (a)  REMEDIES.  The Company and the Investors acknowledge and agree 
that irreparable damage would occur in the event that any of the provisions 
of this Agreement were not performed in accordance with their specific terms 
or were otherwise breached.  It is accordingly agreed that the parties shall 
be entitled to an injunction or injunctions to prevent or cure breaches of 
the provisions of this Agreement and to enforce specifically the terms and 
provisions hereof, this being in addition to any other remedy to which any of 
them may be entitled by law or equity.

          (b)  JURISDICTION.  The Company and each of the Investors (i) 
hereby irrevocably submits to the exclusive jurisdiction of the United States 
District Court, the New York State courts and other courts of the United 
States sitting in New York County, New York for the purposes of any suit, 
action or proceeding arising out of or relating to this Agreement and (ii) 
hereby waives, and agrees not to assert in any such suit action or 
proceeding, any claim that it is not personally subject to the jurisdiction 
of such court, that the suit, action or proceeding is brought in an 
inconvenient forum or that the venue of the suit, action or proceeding is 
improper.  The Company and each of the Investors consents to process being 
served in any such suit, action or proceeding by mailing a copy thereof to 
such party at the address in effect for notices to it under this Agreement 
and agrees that such service shall constitute good and sufficient service of 
process and notice thereof.  Nothing in this paragraph shall affect or limit 
any right to serve process in any other manner permitted by law.

          (c)  NOTICES.  Any notice or other communication required or 
permitted to be given hereunder shall be in writing by facsimile, mail or 
personal delivery and shall be effective upon actual receipt of such notice.  
The addresses for such communications shall be:

          to the Company:

          Zitel Corporation
          47211 Bayside Parkway
          Fremont, California  94538
          Attention: Chief Financial Officer
          Facsimile: (510) 440-8526

          to the Investors:

          To each Investor at the address and/or fax number set forth
          on Schedule I of this Agreement.

          with copies to:

                                     13
<PAGE>


          Kleinberg, Kaplan, Wolff & Cohen, P.C.
          551 Fifth Avenue
          New York, New York 10176
          Facsimile: (212) 986-8866
          Attention: Stephen M. Schultz, Esq.

Any party hereto may from time to time change its address for notices by 
giving at least 10 days' written notice of such changed address to the other 
parties hereto.

          (d)  INDEMNITY.  Each party shall indemnify each other party 
against any loss, cost or damages (including reasonable attorney's fees) 
incurred as a result of such parties' breach of any representation, warranty, 
covenant or agreement in this Agreement.

          (e)  WAIVERS.  No waiver by any party of any default with respect 
to any provision, condition or requirement of this Agreement shall be deemed 
to be a continuing waiver in the future or a waiver of any other provision, 
condition or requirement hereof, nor shall any delay or omission of any party 
to exercise any right hereunder in any manner impair the exercise of any such 
right accruing to it thereafter.  The representations and warranties and the 
agreements and covenants of the Company and each Investor contained herein 
shall survive the Closing.

          (f)  EXECUTION.  This Agreement may be executed in two or more 
counterparts, all of which shall be considered one and the same agreement, it 
being understood that all parties need not sign the same counterpart.

          (g)  ENTIRE AGREEMENT.  This Agreement, together with the Purchase 
Agreement, the Debentures and the Warrants and the agreements and documents 
contemplated hereby and thereby, contains the entire understanding and 
agreement of the parties, and may not be modified or terminated except by a 
written agreement signed by both parties.

          (h)  GOVERNING LAW; CONSENT OF JURISDICTION.  This Agreement and 
the validity and performance of the terms hereof shall be governed by and 
construed and enforced in accordance with the internal laws of the State of 
New York applicable to contracts executed and to be performed entirely in 
such State.

          (i)  SEVERABILITY.  The parties acknowledge and agree that the 
Investors are not agents, affiliates or partners of each other, that all 
representations, warranties, covenants and agreements of the Investors 
hereunder are several and not joint, that no Investor shall have any 
responsibility or liability for the representations, warrants, agreements, 
acts or omissions of any other Investor, and that any rights granted to 
"Investors" hereunder shall be enforceable by each Investor hereunder.

          (j)  JURY TRIAL.  Each party hereto waives the right to a trial by 
jury.

          (k)  TITLES.  The titles used in this Agreement are used for 
convenience only and are not to be considered in construing or interpreting 
this Agreement.

                             [SIGNATURE PAGES FOLLOW ]

                                     14
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be 
duly executed as of the date first above written.

                                    ZITEL CORPORATION

                                    By:       Anna M. McCann
                                             -------------------------------
                                    Name:     Anna M. McCann
                                    Title:    V.P. Finance & Administration

                                    INVESTORS:

                                    HALIFAX FUND, L.P.

                                    By:       Jeffrey E. Devers
                                             -------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President


                                    PALLADIN PARTNERS I, L.P.

                                    By:  PALLADIN GROUP L.P.
                                              Attorney-in-Fact

                                    By:       Jeffrey E. Devers
                                             -------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President


                                    PALLADIN OVERSEAS FUND LIMITED

                                    By:       PALLADIN GROUP L.P.
                                              Attorney-in-Fact

                                    By:       Jeffrey E. Devers
                                             -------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President

 [SIGNATURE PAGE TO ZITEL CORPORATION CONVERTIBLE SUBORDINATED DEBENTURE
 PURCHASE AGREEMENT]

                                     15
<PAGE>

                                    THE GLENEAGLES FUND COMPANY

                                    By:       PALLADIN GROUP L.P.
                                              Attorney-in-Fact

                                    By:       Jeffrey E. Devers
                                             -------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President

                                    PALLADIN SECURITIES, LLC

                                    By:       Jeffrey E. Devers
                                             -------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President

                                    COLONIAL PENN LIFE INSURANCE COMPANY

                                    By:  PALLADIN GROUP L.P.
                                              Attorney-in-Fact

                                    By:       Jeffrey E. Devers
                                             -------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President

                                    LANCER SECURITIES LIMITED

                                    By:  PALLADIN GROUP L.P.
                                              Attorney-in-Fact

                                    By:       Jeffrey E. Devers
                                             -------------------------------
                                    Name:     Jeffrey E. Devers
                                    Title:    President

     [SIGNATURE PAGE TO ZITEL CORPORATION CONVERTIBLE SUBORDINATED DEBENTURE
PURCHASE AGREEMENT]

                                     16

<PAGE>

                                    EXHIBIT 4.4

THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS 
AMENDED, OR ANY STATE SECURITIES LAWS.  IT MAY NOT BE SOLD OR OFFERED FOR 
SALE EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER SAID ACT 
AND ANY APPLICABLE STATE SECURITIES LAW OR AN APPLICABLE EXEMPTION FROM SUCH 
REGISTRATION REQUIREMENTS.

                            ----------------------------

                                 ZITEL CORPORATION

                            ----------------------------

                           Common Stock Purchase Warrant

                                                               February 2, 1999

     ZITEL CORPORATION, a California corporation (the "COMPANY"), hereby 
certifies that for good and valuable consideration, the receipt and 
sufficiency of which are hereby acknowledged, ________________________, 
having an address at _______________________ ("PURCHASER") or any other 
Warrant Holder is entitled, on the terms and conditions set forth below, to 
purchase from the Company at any time beginning on the date hereof and ending 
on the fifth anniversary of the Closing Date, as extended 1.5 times the 
number of days between the 90th day following the Closing Date and such 
anniversary on which there had been no Effective Registration, _________ 
fully paid and nonassessable shares of Common Stock, no par value, of the 
Company (the "COMMON STOCK"), at a purchase price per share of Common Stock 
equal to 130% of the Conversion Price, as such term is defined in the 
Debenture and as such Conversion Price may from time to time be adjusted 
pursuant to the terms of the Debenture and the Agreement (the "PURCHASE 
PRICE"), as the same may be adjusted pursuant to Section 5 herein.

     1.   DEFINITIONS.

          (a)  The term "AGREEMENT" shall mean the Convertible Debenture 
Purchase Agreement dated as of February 2, 1999, between the Company and the 
Investors signatory thereto.

          (b)  The term "APPROVED MARKET" shall mean the Nasdaq National 
Market System,  the American Stock Exchange or the New York Stock Exchange.

          (c)  The term "CLOSING BID PRICE" shall mean the last closing bid 
price on the principal Approved Market as reported by Bloomberg Financial 
Market or an equivalent reliable reporting service selected by the Warrant 
Holder and the Company.

          (d)  The term "DEBENTURE" shall mean any of the Company's 3% 
Convertible Subordinated Debentures due February 1, 2000.

          (e)  The term "EFFECTIVE REGISTRATION" shall have the meaning 
specified in the Agreement.

                                     1
<PAGE>

          (f)  The term "CLOSING DATE" shall mean the Closing Date as defined 
in Section 1.1 under the Agreement.

          (g)  The term "REGISTRATION RIGHTS AGREEMENT" shall mean the 
Registration Rights Agreement, dated as of February 2, 1999, between the 
Company and the Investors signatory thereto.

          (h)  The term "WARRANT HOLDER" shall mean the Purchaser or any 
assignee of all or any portion of this Warrant.

          (i)  The term "WARRANT SHARES" shall mean the Shares of Common 
Stock or other securities issuable upon exercise of this Warrant.

          (j)  The term "MATRIDIGM TRANSACTION" shall mean any transaction or 
series of transactions whereby the Company acquires debt or equity securities 
of Matridigm Corporation, a California corporation, or the business of the 
Company and Matridigm are combined, and shall include, without limitation, 
the issuance for cash of shares of the Common Stock of the Company with a 
fair market value not to exceed $2,000,000, as determined as of the purchase 
date and pursuant to one-time reset provisions agreed to between the Company 
and the purchasers, with the proceeds used to procure the release of 
obligations of the purchasers to guarantee obligations of Matridigm.

     Capitalized terms used but not defined in this Warrant shall have the 
meanings specified in the Agreement or the Debentures.

     2.   EXERCISE OF WARRANT.

          This Warrant may be exercised by the Warrant Holder, in whole or in 
part, at any time and from time to time by either of the following methods:

          (a)  The Warrant Holder may surrender this Warrant, together with 
the form of subscription at the end hereof duly executed by Warrant Holder 
("SUBSCRIPTION NOTICE"), at the offices of the Company or any transfer agent 
for the Common Stock; or

          (b)  The Warrant Holder may also exercise this Warrant, in whole or 
in part, in a "cashless" or "net-issue" exercise by delivering to the offices 
of the Company or any transfer agent for the Common Stock this Warrant, 
together with a Subscription Notice specifying the number of Warrant Shares 
to be delivered to such Warrant Holder ("DELIVERABLE SHARES") and the number 
of Warrant Shares with respect to which this Warrant is being surrendered in 
payment of the aggregate Purchase Price for the Deliverable Shares 
("SURRENDERED SHARES"); provided that the Purchase Price multiplied by the 
number of Deliverable Shares shall not exceed the value of the Surrendered 
Shares; and provided further that the sum of the number of Deliverable Shares 
and the number of Surrendered Shares so specified shall not exceed the 
aggregate number of Warrant Shares represented by this Warrant.  For the 
purposes of this provision, each Warrant Share as to which this Warrant is 
surrendered will be attributed a value equal to the fair market value (as 
defined below) of the Warrant Share minus the Purchase Price of the Warrant 
Share.

                                     2
<PAGE>

     In the event that the Warrant is not exercised in full, the number of 
Warrant Shares shall be reduced by the number of such Warrant Shares for 
which this Warrant is exercised and/or surrendered, and the Company, at its 
expense, shall within three (3) Trading Days (as defined below) issue and 
deliver or upon the order of Warrant Holder a new Warrant of like tenor in 
the name of Warrant Holder or as Warrant Holder (upon payment by Warrant 
Holder of any applicable transfer taxes) may request, reflecting such 
adjusted Warrant Shares.

     3.   DELIVERY OF STOCK CERTIFICATES.

          (a)  Subject to the terms and conditions of this Warrant, as soon 
as practicable after the exercise of this Warrant in full or in part, and in 
any event within three (3) Trading Days thereafter, the Company shall 
transmit the certificates (together with any other stock or other securities 
or property to which Warrant Holder is entitled upon exercise) by messenger 
or overnight delivery service to reach the address designated by such holder 
within three (3) Trading Days after the receipt of the Subscription Notice 
("T+3").  If such certificates are not received by the Warrant Holder within 
T+3, then the Warrant Holder will be entitled to revoke and withdraw its 
exercise of its Warrant at any time prior to its receipt of those 
certificates.

     In lieu of delivering physical certificates representing the Warrant 
Shares deliverable upon exercise of Warrants, provided the Company's transfer 
agent is participating in the Depository Trust Company ("DTC") Fast Automated 
Securities Transfer ("FAST") program, upon request of the Warrant Holder, the 
Company shall use its best efforts to cause its transfer agent to 
electronically transmit the Warrant Shares issuable upon exercise to the 
Warrant Holder, by crediting the account of Warrant Holder's prime broker 
with DTC through its Deposit Withdrawal Agent Commission ("DWAC") system.  
The time periods for delivery described above shall apply to the electronic 
transmittals through the DWAC system.  The parties agree to coordinate with 
DTC to accomplish this objective.  The exchange pursuant to Section 3 shall 
be deemed to have been made immediately prior to the close of business on the 
date of the Subscription Notice.  The person or persons entitled to receive 
the Warrant Shares issuable upon such exercise shall be treated for all 
purposes as the record holder or holders of such Common Shares at the close 
of business on the date of the Subscription Notice.

     The term Trading Day means (x) if the Common Stock is listed on the New 
York Stock Exchange or the American Stock Exchange, a day on which there is 
trading on such stock exchange, (y) if the Common Stock is not listed on 
either of such stock exchanges but sale prices of the Common Stock are 
reported on an automated quotation system, a day on which trading is reported 
on the principal automated quotation system on which sales of the Common 
Stock are reported, or (z) if the foregoing provisions are inapplicable, a 
day on which quotations are reported by National Quotation Bureau 
Incorporated.

          (b)  This Warrant may not be exercised as to fractional shares of 
Common Stock.  In the event that the exercise of this Warrant, in full or in 
part, would result in the issuance of any fractional share of Common Stock, 
then in such event the Warrant Holder shall be entitled to cash equal to the 
fair market value of such fractional share.  For purposes of this Warrant, 
"fair market value" shall equal the Closing Bid Price on the Approved Market 
which is the principal trading exchange or market for the Common Stock (the 
"Principal Market") on the date of determination or, if the Common Stock is 
not listed or admitted to trading on any 

                                     3
<PAGE>

Approved Market, the average of the closing bid and asked prices on the 
over-the-counter market as furnished by any New York Stock Exchange member 
firm reasonably selected from time to time by the Company for that purpose 
and reasonably acceptable to the Warrant Holder, or, if the Common Stock is 
not listed or admitted to trading on any Approved Market or traded 
over-the-counter and the average price cannot be determined a contemplated 
above, the fair market value of the Common Stock shall be as reasonably 
determined in good faith by the Company's Board of Directors with the 
concurrence of the Warrant Holder.

     4.   (A)  REPRESENTATIONS AND COVENANTS OF THE COMPANY.

          (a)  The Company shall comply with its obligations under the 
Registration Rights Agreement with respect to the Warrant Shares, including, 
without limitation, the Company's obligation to have filed and declared and 
maintained effective a registration statement registering the Warrant Shares 
under the Securities Act of 1933, as amended (the "ACT").

          (b)  The Company shall take all necessary action and proceedings as 
may be required and permitted by applicable law, rule and regulation, 
including, without limitation, the notification of the Principal Market, for 
the legal and valid issuance of this Warrant and the Warrant Shares to the 
Warrant Holder under this Warrant.

          (c)  From the date hereof through the last date on which this 
Warrant is exercisable, the Company shall take all steps necessary to insure 
that the Common Stock remains listed on the Principal Market.

          (d)  The Warrant Shares, when issued in accordance with the terms 
hereof, will be duly authorized and, when paid for or issued in accordance 
with the terms hereof, shall be validly issued, fully paid and 
non-assessable.  The Company has authorized and reserved for issuance to 
Warrant Holder the requisite number of shares of Common Stock to be issued 
pursuant to this Warrant.

          (e)  The Company shall at all times reserve and keep available, 
solely for issuance and delivery as Warrant Shares hereunder the number of 
shares specified in Section 3.10 of the Purchase Agreement.

          (f)  With a view to making available to the Warrant Holder the 
benefits of Rule 144 promulgated under the Act and any other rule or 
regulation of the Securities and Exchange Commission ("SEC") that may at any 
time permit Warrant Holder to sell securities of the Company to the public 
without registration, the Company agrees to use its best efforts to:

               (i)   make and keep public information available, as those 
terms are understood and defined in Rule 144, at all times;

               (ii)  file with the SEC in a timely manner all reports and 
other documents required of the Company under the Act and the Securities 
Exchange Act of 1934, as amended (the "Exchange Act"); and

                                     4
<PAGE>

               (iii) furnish to any Warrant Holder forthwith upon request a 
written statement by the Company that it has complied with the reporting 
requirements of Rule 144 and of the Act and the Exchange Act, a copy of the 
most recent annual or quarterly report of the Company, and such other reports 
and documents so filed by the Company as may be reasonably requested to 
permit any such Warrant Holder to take advantage of any rule or regulation of 
the SEC permitting the selling of any such securities without registration.

          (B)  REPRESENTATIONS AND COVENANTS OF THE PURCHASER.

               The Purchaser shall not resell this Warrant or the Warrant 
Shares, unless such resale is pursuant to an effective registration statement 
under the Act or pursuant to an applicable exemption from such registration 
requirements.

     5.   ADJUSTMENT OF PURCHASE PRICE AND NUMBER OF SHARES.  The number of 
and kind of securities purchasable upon exercise of this Warrant and the 
Purchase Price shall be subject to adjustment from time to time as follows:

          (a)  SUBDIVISIONS, COMBINATIONS AND OTHER ISSUANCES.  If the 
Company shall at any time after the date hereof but prior to the expiration 
of this Warrant subdivide its outstanding securities as to which purchase 
rights under this Warrant exist, by split-up, spin-off, or otherwise, or 
combine its outstanding securities as to which purchase rights under this 
Warrant exist, the number of Warrant Shares as to which this Warrant is 
exercisable as of the date of such subdivision, split-up, spin-off or 
combination shall forthwith be proportionately increased in the case of a 
subdivision, or proportionately decreased in the case of a combination. 
Appropriate proportional adjustments (decrease in the case of subdivision, 
increase in the case of combination) shall also be made to the Purchase Price 
payable per share, so that the aggregate Purchase Price payable for the total 
number of Warrant Shares purchasable under this Warrant as of such date shall 
remain the same as it would have been before such subdivision or combination.

          (b)  STOCK DIVIDEND.  If at any time after the date hereof the 
Company declares a dividend or other distribution on Common Stock payable in 
Common Stock or other securities or rights convertible into or exchangeable 
for Common Stock ("COMMON STOCK EQUIVALENTS") without payment of any 
consideration by holders of Common Stock for the additional shares of Common 
Stock or the Common Stock Equivalents (including the additional shares of 
Common Stock issuable upon exercise or conversion thereof), then the number 
of shares of Common Stock for which this Warrant may be exercised shall be 
increased as of the record date (or the date of such dividend distribution if 
no record date is set) for determining which holders of Common Stock shall be 
entitled to receive such dividends, in proportion to the increase in the 
number of outstanding shares (and shares of Common Stock issuable upon 
conversion of all such securities convertible into Common Stock) of Common 
Stock as a result of such dividend, and the Purchase Price shall be 
proportionately reduced so that the aggregate Purchase Price for all the 
Warrant Shares issuable hereunder immediately after the record date (or on 
the date of such distribution, if applicable), for such dividend shall equal 
the aggregate Purchase Price so payable immediately before such record date 
(or on the date of such distribution, if applicable).

                                     5
<PAGE>

          (c)  OTHER DISTRIBUTIONS.  If at any time after the date hereof the 
Company distributes to holders of its Common Stock, other than as part of its 
dissolution, liquidation or the winding up of its affairs, any shares of its 
capital stock, any evidence of indebtedness or any of its assets (other than 
Common Stock), then the number of Warrant Shares for which this Warrant is 
exercisable shall be increased to equal: (i) the number of Warrant Shares for 
which this Warrant is exercisable immediately prior to such event, (ii) 
multiplied by a fraction, (A) the numerator of which shall be the fair market 
value per share of Common Stock on the record date for the dividend or 
distribution, and (B) the denominator of which shall be the fair market value 
per share of Common Stock on the record date for the dividend or distribution 
minus the amount allocable to one share of Common Stock of the value (as 
determined in good faith by the Board of Directors of the Company) of any and 
all such evidences of indebtedness, shares of capital stock, other securities 
or property, so distributed.  If the value of the distribution exceeds 10% of 
the value of the outstanding Common Stock, at the request of Warrant Holders 
holding an aggregate of at least 50,000 Warrants, the valuation described in 
the preceding sentence shall be determined, at the Company's expense, by a 
nationally recognized investment banking firm or other nationally recognized 
financial advisor retained by the Company with the approval of the Warrant 
Holder.  The Purchase Price shall be reduced to equal: (i) the Purchase Price 
in effect immediately before the occurrence of any event (ii) multiplied by a 
fraction, (A) the numerator of which is the number of Warrant Shares for 
which this Warrant is exercisable immediately before the adjustment, and (B) 
the denominator of which is the number of Warrant Shares for which this 
Warrant is exercisable immediately after the adjustment.

          (d)  MERGER, ETC.  If at any time after the date hereof there shall 
be a merger or consolidation of the Company with or into or a transfer of all 
or substantially all of the assets of the Company to another entity, then the 
Warrant Holder shall be entitled to receive upon or after such transfer, 
merger or consolidation becoming effective, and upon payment of the Purchase 
Price then in effect, the number of shares or other securities or property of 
the Company or of the successor corporation resulting from such merger or 
consolidation, which would have been received by Warrant Holder for the 
shares of stock subject to this Warrant had this Warrant been exercised just 
prior to such transfer, merger or consolidation becoming effective or to the 
applicable record date thereof, as the case may be.  The Company will not 
merge or consolidate with or into any other corporation, or sell or otherwise 
transfer its property, assets and business substantially as an entirety to 
another corporation, unless the corporation resulting from such merger or 
consolidation (if not the Company), or such transferee corporation, as the 
case may be, shall expressly assume, by supplemental agreement, the due and 
punctual performance and observance of each and every covenant and condition 
of this Warrant to be performed and observed by the Company, as adjusted to 
preserve the economic benefits receivable by the Warrant Holder upon exercise.

          (e)  In addition to the foregoing, if the holders of shares of 
Common Stock receive any non-publicly traded securities or other property or 
cash as part or all of the consideration for such reorganization, 
consolidation, merger or sale, then such distribution shall be treated to the 
extent thereof as a distribution under Section 7(a) above and such Section 
shall also apply to such distribution.  To the extent that, pursuant to the 
foregoing adjustments, (i) the Warrants become exercisable into securities of 
an issuer with a greater number of outstanding shares of common stock than 
the Company and (ii) on the date of the relevant merger agreement or the date 
on which the terms of the restructuring are set, the fair market value of a 
share of 

                                     6
<PAGE>

Common Stock is less than the Purchase Price, then the adjustments set forth 
in Section 5(f) herein shall also be applied as if the additional shares were 
issued after the effective date of the merger or reorganization.

          (f)  RECLASSIFICATION, ETC.  If at any time after the date hereof 
there shall be a reorganization or reclassification of the securities as to 
which purchase rights under this Warrant exist into the same or a different 
number of securities of any other class or classes, then the Warrant Holder 
shall thereafter be entitled to receive upon exercise of this Warrant, during 
the period specified herein and upon payment of the Purchase Price then in 
effect, the number of shares or other securities or property resulting from 
such reorganization or reclassification, which would have been received by 
the Warrant Holder for the shares of stock subject to this Warrant had this 
Warrant at such time been exercised.

          (g)  PURCHASE PRICE ADJUSTMENT.  In the event that within twelve 
(12) months of the Closing Date the Company issues or sells any Common Stock 
or securities which are convertible into or exchangeable for its Common Stock 
or any convertible securities, or any warrants or other rights to subscribe 
for or to purchase or any options for the purchase of its Common Stock or any 
such convertible securities (other than shares or options issued or which may 
be issued pursuant to the Company's current employee or director option plans 
or stock purchase plans, as amended consistent with the practice in the 
high-technology sector, at prices consistent with past practice, or shares 
issued upon exercise of options, warrants or rights outstanding on the date 
of the Agreement and listed in Section 2(c) of the Company's Disclosure 
Schedule or shares issued in a Matridigm Transaction) at an effective 
purchase price per share which is less than the greater of the Purchase Price 
then in effect or the fair market value (as defined in Section 3(b) above) of 
the Common Stock on the trading day next preceding such issue or sale, then 
in each such case, the Purchase Price in effect immediately prior to such 
issue or sale shall be reduced effective concurrently with such issue or sale 
to an amount determined by multiplying the Purchase Price then in effect by a 
fraction, (x) the numerator of which shall be the sum of (1) the number of 
shares of Common Stock outstanding immediately prior to such issue or sale, 
plus (2) the number of shares of Common Stock which the aggregate 
consideration received by the Company for such additional shares would 
purchase at such fair market value or, Purchase Price as the case may be, 
then in effect; and (y) the denominator of which shall be the number of 
shares of Common Stock of the Company outstanding immediately after such 
issue or sale.

     For the purposes of the foregoing adjustment, in the case of the 
issuance of any convertible securities, warrants, options or other rights to 
subscribe for or to purchase or exchange for, shares of Common Stock 
("CONVERTIBLE SECURITIES"), the maximum number of shares of Common Stock 
issuable upon exercise, exchange or conversion of such Convertible Securities 
shall be deemed to be outstanding, provided that no further adjustment shall 
be made upon the actual issuance of Common Stock upon exercise, exchange or 
conversion of such Convertible Securities.

     The number of shares which may be purchased hereunder shall be increased 
proportionately to any reduction in Purchase Price pursuant to this paragraph 
5(f), so that after such adjustments the aggregate Purchase Price payable 
hereunder for the increased number of shares shall be the same as the 
aggregate Purchase Price in effect just prior to such adjustments.

                                     7
<PAGE>

     In the event of any such issuance for a consideration which is less than 
such fair market value and also less than the Purchase Price then in effect, 
than there shall be only one such adjustment by reason of such issuance, such 
adjustment to be that which results in the greatest reduction of the Purchase 
Price computed as aforesaid.

     6.   NO IMPAIRMENT.  The Company will not, by amendment of its 
Certificate of Incorporation or through any reorganization, transfer of 
assets, consolidation, merger, dissolution, issue or sale of securities or 
any other voluntary action, avoid or seek to avoid the observance or 
performance of any of the terms of this Warrant, but will at all times in 
good faith assist in the carrying out of all such terms and in the taking of 
all such action as may be necessary or appropriate in order to protect the 
rights of the Warrant Holder against impairment.  Without limiting the 
generality of the foregoing, the Company (a) will not increase the par value 
of any Warrant Shares above the amount payable therefor on such exercise, and 
(b) will take all such action as may be reasonably necessary or appropriate 
in order that the Company may validly and legally issue fully paid and 
nonassessable Warrant Shares on the exercise of this Warrant.

     7.   NOTICE OF ADJUSTMENTS.  Whenever the Purchase Price or number of 
Shares purchasable hereunder shall be adjusted pursuant to Section 5 hereof, 
the Company shall execute and deliver to the Warrant Holder a certificate 
setting forth, in reasonable detail, the event requiring the adjustment, the 
amount of the adjustment, the method by which such adjustment was calculated 
and the Purchase Price and number of shares purchasable hereunder after 
giving effect to such adjustment, and shall cause a copy of such certificate 
to be mailed (by first class mail, postage prepaid) to the Warrant Holder.

     8.   RIGHTS AS STOCKHOLDER.  Prior to exercise of this Warrant, the 
Warrant Holder shall not be entitled to any rights as a stockholder of the 
Company with respect to the Warrant Shares, including (without limitation) 
the right to vote such shares, receive dividends or other distributions 
thereon or be notified of stockholder meetings.  However, in the event of any 
taking by the Company of a record of the holders of any class of securities 
for the purpose of determining the holders thereof who are entitled to 
receive any dividend (other than a cash dividend) or other distribution, any 
right to subscribe for, purchase or otherwise acquire any shares of stock of 
any class or any other securities or property, or to receive any other right, 
the Company shall mail to each Warrant Holder, at least 10 Trading Days prior 
to the date specified therein, a notice specifying the date on which any such 
record is to be taken for the purpose of such dividend, distribution or 
right, and the amount and character of such dividend, distribution or right.

     9.   LIMITATION ON EXERCISE.  Notwithstanding anything to the contrary 
contained herein, this Warrant may not be exercised by the Warrant Holder to 
the extent that, after giving effect to Warrant Shares to be issued pursuant 
to a Subscription Notice, the total number of shares of Common Stock deemed 
beneficially owned by such holder (other than by virtue of ownership of this 
Warrant, or ownership of other securities that have limitations on the 
holder's rights to convert or exercise similar to the limitations set forth 
herein), together with all shares of Common Stock deemed beneficially owned 
by the holder's "affiliates" (as defined in Rule 144 of the Act) that would 
be aggregated for purposes of determining whether a group under Section 13(d) 
of the Securities Exchange Act of 1934, as amended (the "EXCHANGE ACT") 
exists, would 

                                     8
<PAGE>

exceed the Warrant Holder's Restricted Ownership Percentage specified on 
Schedule I to the Agreement; provided that (w) each Warrant Holder shall have 
the right at any time and from time to time to reduce its Restricted 
Ownership Percentage immediately upon notice to the Company or in the event 
of a Change in Control Transaction, (x) each Warrant Holder shall have the 
right at any time and from time to time to increase its Restricted Ownership 
Percentage or otherwise waive in whole or in part the restrictions of this 
Section 9 upon 61 days' prior notice to the Company or immediately in the 
event of a Change in Control Transaction, (y) each Warrant Holder can make 
subsequent adjustments pursuant to (w) or (x) any number of times from time 
to time (which adjustment shall be effective immediately if it results in a 
decrease in the Restricted Ownership Percentage or shall be effective upon 61 
days' prior written notice or immediately in the event of a Change in Control 
Transaction if it results in an increase in the Restricted Ownership 
Percentage) and (z) each Warrant Holder may eliminate or reinstate this 
limitation at any time and from time to time (which elimination will be 
effective upon 61 days' prior notice and which reinstatement will be 
effective immediately).  Without limiting the foregoing, in the event of a 
Change in Control Transaction, any holder may reinstate immediately (in whole 
or in part) the requirement that any increase in its Restricted Ownership 
Percentage be subject to 61 days' prior written notice, notwithstanding such 
Change in Control Transaction, without imposing such requirement on, or 
otherwise changing such holder's rights with respect to, any other Change in 
Control Transaction.  For this purpose, any material modification of the 
terms of a Change in Control Transaction will be deemed to create a new 
Change in Control Transaction.  The term "DEEMED BENEFICIALLY OWNED" as used 
in this Warrant shall exclude shares that might otherwise be deemed 
beneficially owned by reason of the convertibility of the Preferred Shares.  
A "CHANGE IN CONTROL TRANSACTION" will be deemed to have occurred upon the 
earlier of the announcement or consummation of a transaction or series of 
transactions (other than the Merger) involving (x) any consolidation or 
merger of the Company with or into any other corporation or other entity or 
person (whether or not the Company is the surviving corporation), or any 
other corporate reorganization or transaction or series of related 
transactions in which in excess of 50% of the Company's voting power is 
transferred through a merger, consolidation, tender offer or similar 
transaction, or (y) in excess of 50% of the Company's Board of Directors 
consists of directors not nominated by the prior Board of Directors of the 
Company, or (z) any person (as defined in Section 13(d) of the Exchange Act, 
together with its affiliates and associates (as such terms are defined in 
Rule 405 under the Act), beneficially owns or is deemed to beneficially own 
(as described in Rule 13d-3 under the Exchange Act without regard to the 
60-day exercise period) in excess of 50% of the Company's voting power.  The 
delivery of a Subscription Notice by the Warrant Holder shall be deemed a 
representation by such holder that it is in compliance with this paragraph.

     10.  REPLACEMENT OF WARRANT.  On receipt of evidence reasonably 
satisfactory to the Company of the loss, theft, destruction or mutilation of 
this Warrant and, in the case of any such loss, theft or destruction of this 
Warrant, on delivery of an indemnity agreement or security reasonably 
satisfactory in form and amount to the Company or, in the case of any such 
mutilation, on surrender and cancellation of such Warrant, the Company at its 
expense promptly will execute and deliver, in lieu thereof a new Warrant of 
like tenor.

                                     9
<PAGE>

     11.  SPECIFIC PERFORMANCE; CONSENT TO JURISDICTION; CHOICE OF LAW.

          (a)  The Company and the Warrant Holder acknowledge and agree that 
irreparable damage would occur in the event that any of the provisions of 
this Warrant were not performed in accordance with their specific terms or 
were otherwise breached.  It is accordingly agreed that the parties shall he 
entitled to an injunction or injunctions to prevent or cure breaches of the 
provisions of this Warrant and to enforce specifically the terms and 
provisions hereof, this being in addition to any other remedy to which either 
of them may be entitled by law or equity.

          (b)  Each of the Company and the Warrant Holder (i) hereby 
irrevocably submits to the exclusive jurisdiction of the state and federal 
courts located in New York County, New York for the purposes of any suit, 
action or proceeding arising out of or relating to this warrant and (ii) 
hereby waives, and agrees not to assert in any such suit, action or 
proceeding, any claim that it is not personally subject to the jurisdiction 
of such court, that the suit, action or proceeding is brought in an 
inconvenient forum or that the venue of the suit, action or proceeding is 
improper.  Each of the Company and the Warrant Holder consents to process 
being served in any such suit, action or proceeding by mailing a copy thereof 
to such party at the address in effect for notices to it under this Warrant 
and agrees that such service shall constitute good and sufficient service of 
process and notice thereof.  Nothing in this paragraph shall affect or limit 
any right to serve process in any other manner permitted by applicable law.

          (c)  The Company and the Warrant Holder irrevocably waive their 
right to trial by jury.

          (d)  This Warrant shall be governed by and construed and enforced 
in accordance with the internal laws of the State of New York applicable to 
contracts executed and to be performed entirely within such State.

     12.  ENTIRE AGREEMENT; AMENDMENTS.  This Warrant, the Exhibits hereto 
and the provisions contained in the Agreement or the Registration Rights 
Agreement or the Debentures contain the entire understanding of the parties 
with respect to the matters covered hereby and thereby and, except as 
specifically set forth herein and therein, neither the Company nor the 
Warrant Holder makes any representation, warranty, covenant or undertaking 
with respect to such matters. No provision of this Agreement may be waived or 
amended other than by a written instrument signed by the party against whom 
enforcement of any such amendment or waiver is sought.

     13.  NOTICES.  Any notice or other communication required or permitted 
to be given hereunder shall be in writing and shall be effective (a) upon 
hand delivery or delivery by telex (with correct answer back received), 
telecopy or facsimile at the address or number designated below (if delivered 
on a business day during normal business hours where such notice is to be 
received), or the first business day following such delivery (if delivered 
other than on a business day during normal business hours where such notice 
is to be received) or (b) on the second business day following the date of 
mailing by express courier service, fully prepaid, addressed to such address, 
or upon actual receipt of such mailing, whichever shall first occur.  The 
addresses for such communications shall be:

                                     10
<PAGE>

     to the Company:

          Zitel Corporation
          47211 Bayside Parkway
          Fremont, California  94538
          Attention: Chief Financial Officer
          Facsimile: (510) 440-8526

     to the Warrant Holder:

          Halifax Fund, L.P.
          c/o The Palladin Group, L.P.
          Investment Manager
          195 Maplewood Avenue
          Maplewood, New Jersey  07040
          Attention: Robert Chender
          Facsimile: (973) 313-6941

     with copies to:

          Kleinberg, Kaplan, Wolff & Cohen, P.C.
          551 Fifth Avenue, 18th Floor
          New York, New York  10176
          Attention: Stephen M. Schultz, Esq.
          Facsimile: (212) 986-8866

Either party hereto may from time to time change its address for notices 
under this Section 13 by giving at least 10 days' prior written notice of 
such changed address to the other party hereto.

     14.  MISCELLANEOUS.  This Warrant and any term hereof may be changed, 
waived, discharged or terminated only by an instrument in writing signed by 
the party against which enforcement of such change, waiver, discharge or 
termination is sought.  The headings in this Warrant are for purposes of 
reference only, and shall not limit or otherwise affect any of the terms 
hereof.  The invalidity or unenforceability of any provision hereof shall in 
no way affect the validity or enforceability of any other provision.

     15.  ASSIGNMENT.  This Warrant may be transferred or assigned, in whole 
or in part, at any time and from time to time by the then Warrant Holder upon 
the consent of the Company (which consent shall not be unreasonably withheld) 
by submitting this Warrant to the Company together with a duly executed 
Assignment in substantially the form and substance of the Form of Assignment 
which accompanies this Warrant and, upon the Company's receipt hereof, and in 
any event, within three (3) business days thereafter, the Company shall issue 
a Warrant to the Warrant Holder to evidence that portion of this Warrant, if 
any as shall not have been so transferred or assigned.  No consent of the 
Company will be required for any transfer or assignment by the Warrant Holder 
to (i) an affiliate or affiliates of the Warrant Holder or (ii) any person or 
entity whose investments are managed by an investment adviser that is the 
same as, or an affiliate of, the investment manager of the Warrant Holder.

                                     11
<PAGE>

 Dated:                                      ZITEL CORPORATION
       ----------------------- 
                                             By:
                                                -------------------------------
                                                  Name:
                                                  Title:

[CORPORATE SEAL]

Attest:

By:
   ---------------------------
     Its



                                     
    (SIGNATURE PAGE OF ZITEL CORPORATION COMMON STOCK PURCHASE WARRANT)

                                     12
<PAGE>

                           (SUBSCRIPTION NOTICE)
                          FORM OF WARRANT EXERCISE
                 (TO BE SIGNED ONLY ON EXERCISE OF WARRANT)

TO:       ZITEL CORPORATION
ATTN:     SECRETARY

     The undersigned, the holder of the within Warrant, hereby irrevocably 
elects to exercise this Warrant:

     _____ (A)   for, and to purchase thereunder, ________ shares of Common 
Stock of Zitel Corporation, a California corporation (the "COMMON STOCK"), 
and herewith, or by wire transfer, makes payment of $______________ therefor; 
or

     _____ (B)   in a "cashless" or "net-issue exercise" for, and to purchase 
thereunder , ______ shares of Common Stock, and herewith makes payment 
therefor with _________ Surrendered Warrant Shares.

     The undersigned requests that the certificates for such shares be issued 
in the name of, and

     _____ (A)   delivered to __________, whose address is _____________; or

     _____ (B)   electronically transmitted and credited to the account of 
_______________, undersigned's prime broker (Account No. __________) with 
Depository Trust Company through its Deposit Withdrawal Agent Commission 
system.

     The undersigned acknowledges and confirms that the Common Stock issued 
pursuant to this notice of exercise has been sold or will be sold in 
accordance with the prospectus delivery requirements of the Securities Act of 
1933, as amended, if applicable, or pursuant to an exemption under such Act.

Dated:
      ---------------------------

(Signature must conform to name of holder
as specified on the face of the Warrant)

- ---------------------------------
(Address)

Tax Identification Number:
                          -------------

                                     13
<PAGE>

                                 FORM OF ASSIGNMENT
                     (TO BE SIGNED ONLY ON TRANSFER OF WARRANT)

     For value received, the undersigned hereby sells, assigns, and transfers 
unto _____________ the right represented by the within Warrant to purchase 
________ shares of Common Stock of a California corporation, to which the 
within Warrant relates, and ZITEL CORPORATION, appoints ________________ 
Attorney to transfer such right on the books of ZITEL CORPORATION, a 
California corporation, with full power of substitution of premises.

Dated:
      ------------------------------

(Signature must conform to name of holder
as specified on the face of the Warrant)

- ------------------------------------
(Address)

Signed in the presence of:


- ------------------------------------


                                     14

<PAGE>

                                    EXHIBIT 4.5

                                 Zitel Corporation

                       3% Convertible Debentures Due 2000 and
                           Common Stock Purchase Warrants

                             PLACEMENT AGENCY AGREEMENT

                                  February 1, 1999

Rochon Capital Group, Ltd.
  As Placement Agent
16 Mary Street, Suite 2000
San Rafael, California  94901

Ladies and Gentlemen:

     This letter confirms the agreement (this "Agreement") of Zitel 
Corporation, a California corporation (the "Company"), to retain Rochon 
Capital Group, Ltd., a California corporation (the "Placement Agent"), as the 
Company's exclusive agent from February 1, 1999 through and including March 
1, 1999 (the "Engagement Period") to identify for the Company prospective 
purchasers (collectively, the "Purchasers" and each individually, a 
"Purchaser") in a placement (the "Placement") of up to U.S. $5,000,000.00 
aggregate principal amount of the Company's 3% Convertible Debentures Due 
2000 (the "Debentures") convertible into shares of the Company's common 
stock, no par value per share (the "Common Stock"), and up to 75,000 warrants 
(the "Warrants") exercisable into shares of Common Stock.  The Debentures and 
Warrants are collectively referred to herein as the "Securities."

     Terms of the Placement are set forth in the subscription documents, 
including the convertible debenture purchase agreement, convertible 
subordinated debenture, registration rights agreement, and common stock 
purchase warrant, issued in connection with the Placement (collectively, the 
"Subscription Documents").

     The Placement Agent will act on a best efforts basis and will have no 
obligation to purchase any of the Securities offered by the Company in the 
Placement.  During the Engagement Period, the Placement Agent shall have the 
exclusive right to make all offers and to arrange for all sales of securities 
by the Company, including without limitation the exclusive right to identify 
buyers for the Securities.  The Engagement Period shall be automatically 
extended for a reasonable number of days if, during the Engagement Period, 
sales relating to commitments from Purchasers are not consummated during the 
Engagement Period due to delays in the preparation of final documentation; 
provided, however, that in no event will the Engagement Period be 
automatically extended beyond March 15, 1999 without the written consent of 
the Company and the Placement Agent.

     The Placement is intended to be exempt from the registration 
requirements of the Securities Act of 1933, as amended (the "Securities 
Act"), pursuant to Regulation D 

<PAGE>

Rochon Capital Group, Ltd.
February 1, 1999
Page 2


("Regulation D") of the rules and regulations of the Securities and Exchange 
Commission (the "SEC") promulgated under the Securities Act.

     In order to effectuate the Closing (as defined in Section 1 hereof), the 
Company, the Placement Agent and a bank reasonably acceptable to both parties 
(the "Escrow Agent") shall enter into an escrow agreement (the "Escrow 
Agreement").

     The engagement described herein shall be in accordance with applicable 
laws and pursuant to the following procedures, terms and conditions:

     1.   REPRESENTATIONS AND WARRANTIES OF THE COMPANY.   The 
representations and warranties of the Company made to the Purchasers as set 
forth in the Subscription Documents are hereby incorporated by reference as 
of the date of consummation of the sale of the Securities (the "Closing") and 
all such representations and warranties are hereby deemed made by the Company 
directly to the Placement Agent as though set forth in full herein.

     2.   COVENANTS OF THE COMPANY.

          (a)  The covenants of the Company made to the Purchasers as set 
forth in the Subscription Documents are hereby incorporated by reference as 
of the Closing and all such covenants are hereby deemed made by the Company 
directly to the Placement Agent as though set forth in full herein.

          (b)  Neither the Company nor any affiliate of the Company (as 
defined in Rule 501(b) of Regulation D) will sell, offer for sale or solicit 
offers to buy or otherwise negotiate in respect of any security (as defined 
in the Securities Act) which will be integrated with the sale of the 
Securities or the shares of Common Stock issuable upon conversion of the 
Debentures or exercise of the Warrants (the "Underlying Common Shares") in a 
manner which would require the registration under the Securities Act of the 
Securities or the Underlying Common Shares.

          (c)  Any and all filings and documents required to be filed in 
connection with or as a result of the Placement pursuant to federal and state 
securities laws are the responsibility of the Company and will be filed by 
the Company.

          (d)  Any press release to be issued by the Company announcing or 
referring to the Placement shall be subject to the prior review of the 
Placement Agent, and each such press release shall, at the request of the 
Placement Agent, identify Rochon Capital Group, Ltd. as the placement agent.  
This Agreement shall not be filed publicly by the Company without the prior 
written consent of the Placement Agent.

     3.   COVENANTS OF THE PLACEMENT AGENT.   On the basis of, and in 
reliance on, the representations, warranties and covenants of the Purchasers 
set forth in the Subscription Documents, the Placement Agent hereby covenants 
with the Company as follows:

          (a)  The Placement Agent will take no action, nor fail to take any 
action, if such action or failure to take such action would have the effect 
that the offer or sale of the 

<PAGE>

Rochon Capital Group, Ltd.
February 1, 1999
Page 3


Securities would not be exempt from the registration requirements of the 
Securities Act pursuant to Regulation D.

          (b)  No action is being taken or is contemplated by the Placement 
Agent that would permit a public offering of the Securities in any 
jurisdiction where, or in any other circumstance in which, action for those 
purposes is required (other than in jurisdictions where such action has been 
duly taken). The Placement Agent will comply with applicable laws and 
regulations in any jurisdiction in which it may offer, sell or deliver the 
Securities and will not, directly or indirectly, offer, sell or deliver the 
Securities or distribute or publish any prospectus, circular, advertisement 
or other offering material in relation to the Securities in or from any 
country or jurisdiction except under circumstances that will result in 
compliance with any applicable laws and regulations, and all offers, sales 
and deliveries of the Securities by it will be made on the foregoing terms.

     4.   COMPENSATION OF THE PLACEMENT AGENT; EXPENSES.   As compensation 
for services rendered by the Placement Agent in connection with the 
transaction contemplated herein, the Company agrees to pay the Placement 
Agent, directly from the escrowed funds at the Closing, a fee of 3.5% of the 
gross proceeds from the sale of the Securities (the "Agency Fee").  In 
addition, the Company agrees to pay to the Placement Agent, directly from the 
escrowed funds at the Closing, an expense allowance of $10,000.00 as 
reimbursement for the Placement Agent's expenses, including without 
limitation attorney fees and costs, travel-related expenses and estimated 
telephone, facsimile and postage charges (the "Expense Reimbursement").  
Costs incurred by the Placement Agent in excess of the Expense Reimbursement 
shall be the Placement Agent's sole responsibility.  The Company will pay all 
of its expenses incurred in connection with the Placement and will also pay 
the Escrow Agent's fee and the reasonable accountable attorney fees and costs 
incurred by one investor.

     5.   CLOSING.  The Closing may be held at such place or places as shall 
be specified by the Placement Agent and reasonably agreed to by the Company. 
Certificates evidencing the Securities in the names of the respective 
Purchasers and in the respective denominations aggregating all of the 
Securities sold at the Closing shall be delivered by the Company to the 
Escrow Agent.

     6.   CONDITIONS TO CLOSING.   The Company and the Placement Agent agree 
that the issuance and sale of the Securities and all obligations of the 
Placement Agent provided herein shall be subject to the receipt by the 
Placement Agent of (i) a legal opinion of the Company's securities counsel, 
indicating that the Placement Agent is entitled to rely thereon, in the form 
required to be delivered to the Purchasers pursuant to the Subscription 
Documents and (ii) an escrow agreement duly executed by the Company in a form 
reasonably satisfactory to the Placement Agent.

     7.   INDEMNIFICATION.

          (a)  The Company will indemnify and hold harmless the Placement 
Agent and each of its partners, directors, officers, associates, affiliates , 
subsidiaries, divisions, employees, 

<PAGE>

Rochon Capital Group, Ltd.
February 1, 1999
Page 4


consultants, attorneys and agents, and each person, if any, controlling 
either the Placement Agent or any of its affiliates within the meaning of 
either Section 15 of the Securities Act or Section 20 of the Securities 
Exchange Act of 1934, as amended (the "Exchange Act"), from and against any 
and all losses, claims, damages, liabilities, costs or expenses (and any 
legal or other expenses incurred by the Placement Agent in investigating or 
defending the same or in giving testimony or furnishing documents in response 
to a request of any government agency or to a subpoena) in any way relating 
to or in any way arising out of (i) the activities of the Placement Agent 
contemplated by this Agreement or in connection with the Placement, (ii) the 
inaccuracy of any representation or warranty, or the breach of any covenant, 
contained herein, or (iii) any offering documents or offering materials; and 
will reimburse, as incurred, the Placement Agent and each such controlling or 
other person for any legal or other expenses incurred by the Placement Agent 
or such controlling or other person in connection with investigating, 
defending or appearing as a third-party witness in connection with any such 
loss, claim, damage, liability or action.  Such indemnity shall not, however, 
cover any such loss, claim, damage, liability, cost or a breach by the 
Placement Agent of its obligations in Section 3 hereof (a "Non-Indemnity 
Event") or the willful misconduct of any person seeking indemnification 
hereunder.

          (b)  The Placement Agent will indemnify and hold harmless the 
Company and each person, if any, controlling the Company within the meaning 
of either Section 15 of the Securities Act or Section 20 of the Exchange Act, 
to the same extent set forth in subsection (a) above, but only to the extent 
that any loss, claim, damage, liability, cost or expense arises out of or is 
based upon a Non-Indemnity Event.

          (c)  If any action, proceeding or investigation is commenced by a 
third party as to which the indemnified party hereunder proposes to demand 
indemnification under this Agreement, it will notify the indemnifying party 
with reasonable promptness.  The indemnified party shall have the right to 
retain counsel of its own choice (which choice shall be reasonably 
satisfactory to the indemnifying party) to represent it and such counsel 
shall, to the extent consistent with its professional responsibilities, 
cooperate with the indemnifying party and any counsel designated by the 
indemnifying party.  The indemnifying party will not be liable under this 
Agreement for any settlement of any claim against the indemnifying party made 
without the indemnifying party's written consent, which consent shall not be 
unreasonably withheld. Notwithstanding anything to the contrary contained in 
the foregoing subsection (b) or the following subsection (d), the Placement 
Agent shall not be obligated to pay, and will not pay, any amount in respect 
of its obligation to indemnify or contribute greater than the Agency Fee (as 
defined in Section 4 hereof).

          (d)  In order to provide for just and equitable contribution, if a 
claim for indemnification pursuant to this Section 7 is made but it is found 
in a final judgment by a court of competent jurisdiction (not subject to 
further appeal) that such indemnification may not be enforced in such case, 
even though the express provisions hereof provided for indemnification in 
such case, then the Company, on the one hand, and the Placement Agent, on the 
other hand, shall contribute to the losses, claims, damages, liabilities or 
costs to which the indemnified persons may be subject in accordance with the 
relative benefits received from the Placement of the Securities by the 
Company, on the one hand, and the Placement Agent, on the other hand, and 

<PAGE>

Rochon Capital Group, Ltd.
February 1, 1999
Page 5


also the relative fault of the Company, on the one hand, and the Placement 
Agent, on the other hand, in connection with the statements, acts or 
omissions which resulted in such losses, claims, damages, liabilities or 
costs, and the relevant equitable considerations shall also be considered.  
No person found liable for a fraudulent misrepresentation shall be entitled 
to contribution from any person who is not also found liable for such 
fraudulent misrepresentation.

     8.   NON-CIRCUMVENTION; RIGHT OF FIRST REFUSAL.

          (a)  NON-CIRCUMVENTION.  The Company hereby agrees that, for a 
period of two years form the end of the Engagement Period, the Company will 
not enter into any agreement, transaction or arrangement with any of the 
institutions (including their agents, principals and affiliates and the 
accounts and funds which they manage or advise) which the Placement Agent has 
identified to the Company as prospective purchasers of the Securities in the 
Placement (collectively, the "Rochon Contacts"), regardless of whether a 
transaction is consummated with such prospective purchasers, unless the 
Company notifies the Placement Agent in writing of the agreement, transaction 
or arrangement, and pays the Placement Agent the Agency Fee set forth in 
Paragraph 4 hereof.  Within five business days after the expiration of the 
Engagement Period, the Placement Agent will provide the Company with a list 
of the Rochon Contacts, which list and names the Company agrees to hold 
strictly confidential.  Notwithstanding the foregoing, the parties agree that 
the prospective purchasers whose names appear on the list submitted to the 
Company by the Placement Agent in a letter dated May 23, 1997 shall continue 
to be subject to the provisions of Section 8(a) of the placement agency 
agreement by and between the Company and the Placement Agent dated May 19, 
1997, and shall not be subject to the two-year limitation referred to in the 
first sentence of Section 8(a) of this Agreement; and, in addition, the 
parties agree that the list of prospective purchasers whose names appear in a 
letter to the Company from the Placement Agent dated June 19, 1998 shall be 
deemed to have been delivered to the Company by the Placement Agent within 
five business days after the expiration of the Engagement Period, as such 
term is defined in this Agreement, and the Placement Agent shall not be 
required to submit any additional lists of names in order to receive the 
non-circumvention protections described in this Section 8(a).

          (b)  RIGHT OF FIRST REFUSAL.  For a period of two hundred forty 
(240) days from the Closing Date, if the Company desires to sell any equity 
securities of the Company or any securities convertible into or exchangeable 
or exercisable for any equity securities of the Company (other than in 
connection with underwritten public offerings, acquisitions or strategic 
alliances in which the Company issues securities to potential corporate 
partners), then the Company shall offer the Placement Agent in writing the 
exclusive right to identify buyers for such securities upon terms that are 
reasonably acceptable to the Company and the Placement Agent.  The Company 
shall set forth all terms of the Subsequent Transaction in the written offer 
to the Placement Agent and the Placement Agent will then have 10 business 
days from the date of the offer to accept or reject it.  If accepted, the 
Placement Agent will have an additional 10 business days from acceptance to 
obtain commitments from investors to purchase the securities, or the Company 
will then be free to engage others to assist it in offering such securities 
on identical terms.  If the Company chooses to offer or sell securities in 
the Subsequent Transaction on terms which differ in any way from those set 
forth in the written offer to the Placement 

<PAGE>

Rochon Capital Group, Ltd.
February 1, 1999
Page 6


Agent, then the Company must offer the Placement Agent in writing the right 
to act as the Company's exclusive agent in the Subsequent Transaction on the 
modified terms.  The foregoing notwithstanding, in the event of a Change of 
Control of the Company (as that term is defined in the Subscription 
Documents), the right of first refusal set forth in this Section 8(b) shall 
terminate.

     9.   SURVIVAL.  The respective indemnities of the Company and the 
Placement Agent and the representations, warranties and agreements of the 
Company set forth in or made pursuant to this Agreement will remain in full 
force and effect, regardless of any termination or cancellation of this 
Agreement or any investigation made by or on behalf of the Placement Agent, 
the Company or any person referred to in Section 7 hereof, and shall be 
binding upon any successors and assigns of the Company and shall survive any 
termination of this Agreement and/or issuance of the Securities.  Any 
successor or assign of the Placement Agent and/or its designees, the Company 
or any such person or any legal representative of such person shall be 
entitled to the benefit of the respective indemnities, agreements, warranties 
and representations contained herein.

     10.  TERMINATION.  Either party may terminate this Agreement by giving 
notice as hereinafter specified at any time after March 15, 1999 if the 
Closing has not occurred by such date.  In the event of termination pursuant 
to this Section 10, the Company shall remain obligated to pay the Expense 
Reimbursement as set forth in Section 4 hereof.  Subject to the foregoing 
sentence, any termination pursuant to this Section 10 shall be without 
liability of either party to the other party except as provided in the 
immediately preceding sentence.

     11.  General Provisions.

          (a)  PARTIES.  This Agreement shall inure solely to the benefit of, 
and shall be binding upon, the Placement Agent, the Company, the controlling 
and other persons referred to in Section 7 hereof, and their respective 
successors, legal representatives, heirs, designees and assigns, and no other 
person shall have or be construed to have any legal or equitable right, 
remedy or claim under or in respect of or by virtue of this Agreement or any 
provision herein contained.

          (b)  AMENDMENT.  No amendment or modification hereto, or waiver of 
the terms hereof, shall be valid unless in a writing executed by each of the 
parties hereto or by the party or parties to be bound.

          (c)  NOTICES.  All notices, requests and other communications under 
this Agreement shall be in writing and shall be deemed to have been delivered 
48 hours after having been mailed in a general or branch post office and 
enclosed in a registered or certified postpaid envelope; 24 hours after 
having been sent by overnight courier; when delivered to a telegraph company 
or when scanned graphically or otherwise by telegraphic communications 
equipment of the sending party and accompanied by a substantially 
contemporaneous telephone call; and, in each case, addressed to the 
respective parties at the addresses stated below or to such other 

<PAGE>

Rochon Capital Group, Ltd.
February 1, 1999
Page 7


changed addresses as the parties may have fixed by notice; provided, however, 
that any notice of change of address shall be effective only upon receipt.

     To the Company:               Zitel Corporation
                                   47211 Bayside Parkway
                                   Fremont, California  94538
                                   Attention:     Chief Financial Officer
                                   Telephone:     510-440-9600
                                   Facsimile:     510-440-8526

     with a copy to:               Cooley Godward LLP
                                   One Maritime Plaza, 20th Floor
                                   San Francisco, California  94111
                                   Attention:     John L. Cardoza, Esq.
                                   Telephone:     415-693-2045
                                   Facsimile:     415-951-3699

     To the Placement Agent:       Rochon Capital Group, Ltd.
                                   16 Mary Street, Suite 2000
                                   San Rafael, California  94901
                                   Attention:     Phillip L. Neiman
                                   Telephone:     415-256-2400
                                   Facsimile:     415-256-1214

     with a copy to:               Bryan Cave LLP
                                   700 Thirteenth Street, N.W.
                                   Washington, D.C.
                                   Attention:     LaDawn Naegle, Esq.
                                   Telephone:     202-508-6046
                                   Facsimile:     202-508-6200

          (d)  SEVERABILITY.  If any provision of this Agreement, other than 
Section 4, Section 7 and Section 8, is found to be unenforceable, invalid or 
illegal, and cannot be modified to the satisfaction of the Placement Agent, 
such provision shall be deemed deleted from this Agreement and the remainder 
of this Agreement shall not be affected or impaired thereby.

          (e)  ATTORNEYS' FEES.  If any action, including, without 
limitation, arbitration, should arise among the parties hereto to enforce or 
interpret the provisions of this Agreement, the prevailing party in such 
action shall be reimbursed for all reasonable expenses incurred in connection 
with such action, including reasonable attorneys' fees and costs.

          (f)  INTEGRATION.  This Agreement expresses the entire agreement 
and understanding of the parties hereto with respect to the matters set forth 
herein and supersedes all prior written and oral agreements and 
understandings among the parties hereto with respect to the matters set forth 
herein.

<PAGE>

Rochon Capital Group, Ltd.
February 1, 1999
Page 8


          (g)  GOVERNING LAW.  This Agreement shall be construed and enforced 
in accordance with the laws of the State of California without regard to its 
principles of  conflicts of laws.

          (h)  COUNTERPARTS.  This Agreement may be executed in any number of 
counterparts, each of which shall constitute an original, but all of which 
shall together constitute one and the same agreement.  Facsimile signatures 
are considered to be originals and shall have the same effect.

          (i)  FURTHER ASSURANCES.  The parties agree to execute any and all 
such further agreements, instruments or documents, and to take any and all 
such further action, as may be necessary or desirable to carry into effect 
the purpose and intent of this Agreement.

          (j)  HEADINGS.  The headings in this Agreement are for convenience 
of reference only and are in no way intended to describe, interpret, define, 
modify, add to, or limit the scope, extent or intent of, this Agreement or 
any provision hereof.


                   [SIGNATURES APPEAR ON THE FOLLOWING PAGE]

<PAGE>

Rochon Capital Group, Ltd.
February 1, 1999
Page 9


     If the foregoing correctly sets forth the understandings among the 
Placement Agent and the Company, please so indicate in the space provided 
below for that purpose, whereupon this letter shall constitute a binding 
agreement among us.

                                   Very truly yours,

                                   ZITEL CORPORATION

                                   By:  /s/ Ann M. McCann
                                        -----------------------------------
                                        Name:     Anna M. McCann
                                        Title:    Vice President Finance &
                                                  Administration

ACCEPTED AND AGREED TO AS OF
THE DATE FIRST WRITTEN ABOVE:

ROCHON CAPITAL GROUP, LTD.

By:  /s/ Phillip L. Neiman
     ------------------------------
     Name:     Phillip L. Neiman
     Title:    President




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