AFFYMETRIX INC
S-3, 1999-12-10
COMMERCIAL PHYSICAL & BIOLOGICAL RESEARCH
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<PAGE>
   AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON DECEMBER 10, 1999
                                                      REGISTRATION NO. 333-
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------

                                    FORM S-3
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                            ------------------------

                                AFFYMETRIX, INC.
             (Exact Name Of Registrant As Specified In Its Charter)
                         ------------------------------

<TABLE>
<S>                                                       <C>
                        DELAWARE                                                 77-0319159
            (State or Other Jurisdiction of                                   (I.R.S. Employer
             Incorporation or Organization)                                 Identification No.)
</TABLE>

                            3380 CENTRAL EXPRESSWAY
                         SANTA CLARA, CALIFORNIA 95051
                                 (408) 731-5000
  (Address, including zip code, and telephone number, including area code, of
                   registrant's principal executive offices)
                         ------------------------------

                               VERN NORVIEL, ESQ.
               SENIOR VICE PRESIDENT, GENERAL COUNSEL & SECRETARY
                                AFFYMETRIX, INC.
                            3380 CENTRAL EXPRESSWAY
                         SANTA CLARA, CALIFORNIA 95051
                                 (408) 731-5000
 (Name, address, including zip code, and telephone number, including area code,
                             of agent for service)
                         ------------------------------

                                    COPY TO:

                            STANLEY F. FARRAR, ESQ.
                              SULLIVAN & CROMWELL
                             1888 CENTURY PARK EAST
                                   SUITE 2100
                       LOS ANGELES, CALIFORNIA 90067-1725
                                 (310) 712-6600
                         ------------------------------

    APPROXIMATE DATE OF PROPOSED SALE TO THE PUBLIC: From time to time after the
effective date of this registration statement.

    If the only securities being registered on this form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box. / /

    If any of the securities being registered on this form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or interest
reinvestment plans, check the following box. /X/

    If this form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering. / /

    If this form is a post-effective amendment filed pursuant to
Rule 462(c) under the Securities Act, check the following box and list the
Securities Act registration statement number of the earlier effective
registration statement for the same offering. / /

    If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. / /
                         ------------------------------

                        CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
                                                              PROPOSED MAXIMUM     PROPOSED MAXIMUM
                                           AMOUNT TO BE        AGGREGATE PRICE    AGGREGATE OFFERING      AMOUNT OF
 TITLE OF SECURITIES TO BE REGISTERED       REGISTERED            PER UNIT               PRICE         REGISTRATION FEE
<S>                                     <C>                  <C>                  <C>                  <C>
5% Convertible Subordinated Notes Due
  2006................................     $150,000,000          100%(1)(2)         $150,000,000(1)       $39,600
Common Stock, $0.01 par value.........  1,219,515 shares(3)         --(4)                --(4)             --(4)
</TABLE>

(1) Estimated solely for purposes of calculating the registration fee in
    accordance with Rule 457(i) of the Securities Act of 1933.
(2) Exclusive of accrued interest and distributions, if any.
(3) This number represents the number of shares of common stock that are
    initially issuable upon conversion of the 5% Convertible Subordinated Notes
    Due 2006 registered hereby. For purposes of estimating the number of shares
    of common stock to be registered, Affymetrix calculated the number of shares
    issuable upon conversion of the notes based on a conversion rate of 8.1301
    shares per $1,000 principal amount of notes. In addition, the number of
    shares set forth in the table to be registered includes an indeterminate
    number of shares of common stock issuable upon conversion of the notes, as
    this amount may be adjusted as a result of stock splits, stock dividends and
    antidilution provisions.
(4) No additional consideration will be received for the common stock, and
    therefore no registration fee is required pursuant to Rule 457(i).
                         ------------------------------

    THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(A),
MAY DETERMINE.

- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
<PAGE>
               SUBJECT TO COMPLETION   -  DATED DECEMBER 10, 1999
THE INFORMATION IN THIS PROSPECTUS IS NOT COMPLETE AND MAY BE CHANGED. THESE
SECURITIES MAY NOT BE SOLD UNTIL THE REGISTRATION STATEMENT FILED WITH THE
SECURITIES AND EXCHANGE COMMISSION IS DECLARED EFFECTIVE. THIS PROSPECTUS IS NOT
AN OFFER TO SELL THESE SECURITIES AND IS NOT SOLICITING AN OFFER TO BUY THESE
SECURITIES IN ANY STATE WHERE THE OFFER OR SALE IS NOT PERMITTED.
<PAGE>
P R O S P E C T U S

                                AFFYMETRIX, INC.

                                  $150,000,000

                 5% CONVERTIBLE SUBORDINATED NOTES DUE 2006 AND

                   1,219,515 SHARES OF COMMON STOCK ISSUABLE
                          UPON CONVERSION OF THE NOTES
                               ------------------

    This prospectus relates to the 5% Convertible Subordinated Notes Due 2006 of
Affymetrix, Inc., a Delaware corporation, held by certain security holders who
may offer for sale the notes and the shares of our common stock into which the
notes are convertible at any time at market prices prevailing at the time of
sale or at privately negotiated prices. The selling security holders may sell
the notes or the common stock directly to purchasers or through underwriters,
broker-dealers or agents, who may receive compensation in the form of discounts,
concessions or commissions.

    We will pay interest on the notes on October 1 and April 1 of each year,
commencing on April 1, 2000.

    The notes are convertible at any time prior to maturity into shares of our
common stock at a conversion price of $123.00 per share, which is equivalent to
a conversion rate of 8.1301 shares of our common stock per $1,000 principal
amount of notes. This conversion rate is subject to adjustment under the terms
of the notes. The notes are general, unsecured obligations that are subordinated
to all existing and future senior indebtedness.

    We may redeem the notes on or after October 7, 2002. Holders of the notes
may require us to repurchase the notes upon a Change in Control, except that
this repurchase right does not apply to transactions in which at least 90% of
the consideration consists of common stock and in certain other circumstances.
At our option, we may repurchase the notes for cash or common stock. See
"Description of Notes--Certain Rights to Require Purchase of Notes Upon a Change
In Control."

    Our common stock is listed on the Nasdaq National Market under the symbol
"AFFX." The last reported sale price of our common stock on the Nasdaq National
Market on December 9, 1999 was $106.44 per share. The notes are currently
eligible for trading on the PORTAL Market of the Nasdaq Stock Market.

    INVESTING IN OUR COMMON STOCK OR OUR NOTES INVOLVES RISKS. PLEASE CAREFULLY
CONSIDER THE "RISK FACTORS" BEGINNING ON PAGE 4 OF THIS PROSPECTUS.

    NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR PASSED UPON THE
ADEQUACY OR ACCURACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.

    In connection with this offering, no person is authorized to give any
information or to make any representations not contained in this prospectus. If
information is given or representations are made, you may not rely on that
information or representations as having been authorized by us. This prospectus
is neither an offer to sell nor a solicitation of an offer to buy any securities
other than those registered by this prospectus, nor is it an offer to sell or a
solicitation of an offer to buy securities where an offer or solicitation would
be unlawful. You may not imply from the delivery of this prospectus, nor from
any sale made under this prospectus, that our affairs are unchanged since the
date of this prospectus or that the information contained in this prospectus is
correct as of any time after the date of this prospectus.

               The date of this prospectus is             , 1999.
<PAGE>
                               TABLE OF CONTENTS

<TABLE>
<S>                                                           <C>
SUMMARY.....................................................    3
RISK FACTORS................................................    4
FORWARD-LOOKING STATEMENTS..................................   17
WHERE YOU CAN FIND MORE INFORMATION.........................   17
INCORPORATION BY REFERENCE..................................   17
USE OF PROCEEDS.............................................   19
RATIO OF EARNINGS TO FIXED CHARGES..........................   19
DESCRIPTION OF NOTES........................................   20
CERTAIN UNITED STATES FEDERAL INCOME TAX CONSIDERATIONS.....   34
SELLING SECURITY HOLDERS....................................   39
PLAN OF DISTRIBUTION........................................   41
VALIDITY OF THE SECURITIES..................................   42
EXPERTS.....................................................   42
</TABLE>

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

    You should rely only on the information contained in this document or to
which we have referred you. We have not authorized anyone to provide you with
information that is different. This document may only be used where it is legal
to sell these securities. The information in this document may only be accurate
on the date of this document.

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

                                       2
<PAGE>
                                    SUMMARY

    THE FOLLOWING SUMMARY IS QUALIFIED IN ITS ENTIRETY BY THE MORE DETAILED
INFORMATION APPEARING ELSEWHERE IN THIS PROSPECTUS. YOU SHOULD CONSIDER
CAREFULLY THE INFORMATION SET FORTH IN THIS PROSPECTUS UNDER THE HEADING "RISK
FACTORS." UNLESS INDICATED OTHERWISE, REFERENCES TO "AFFYMETRIX" OR TO THE
"COMPANY" OR TO "WE" OR "US" REFER TO AFFYMETRIX, INC.

                                AFFYMETRIX, INC.

    Affymetrix is recognized as one of the worldwide leaders in developing and
commercializing high-quality DNA chip probe array technology and systems. We
have developed and presently market GeneChip-Registered Trademark- systems, our
proprietary probe array platform, which is used for acquiring, analyzing and
managing complex genetic information to facilitate and improve the
understanding, diagnosis, monitoring and treatment of disease.

    Our GeneChip system consists of disposable DNA probe arrays containing gene
sequences on a glass chip, reagents for use with the probe arrays, a scanner and
other instruments that process the arrays and software that analyzes and manages
genetic information from probe arrays. Commercial sales of our GeneChip system
began in April 1996, and we currently sell our products to pharmaceutical and
biotechnology companies, academic research centers and clinical reference
laboratories.

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

    We are a Delaware corporation. Our headquarters are located at 3380 Central
Expressway, Santa Clara, California 95051. Our telephone number is
(408) 731-5000, and our e-mail address is [email protected]. We also maintain
an Internet home page at affymetrix.com. Information contained on our home page
is not part of this prospectus.

                                       3
<PAGE>
                                  RISK FACTORS
                          RISKS RELATING TO THE NOTES

SUBSTANTIAL LEVERAGE AND DEBT SERVICE OBLIGATIONS MAY ADVERSELY AFFECT OUR CASH
FLOW.

    Affymetrix has substantial amounts of outstanding indebtedness, primarily
the notes. As a result of this indebtedness, Affymetrix' principal and interest
payment obligations will increase substantially. There is the possibility that
Affymetrix may be unable to generate cash sufficient to pay the principal of,
interest on and other amounts due in respect of its indebtedness when due.
Affymetrix also expects to add additional equipment loans and lease lines to
finance capital expenditures and may obtain additional long term debt, working
capital lines of credit and lease lines. There can be no assurance that any
financing arrangements will be available.

    Affymetrix' substantial leverage could have significant negative
consequences, including:

    - increasing Affymetrix' vulnerability to general adverse economic and
      industry conditions;

    - limiting Affymetrix' ability to obtain additional financing;

    - requiring the dedication of a substantial portion of Affymetrix' expected
      cash flow from operations to service its indebtedness, thereby reducing
      the amount of Affymetrix' expected cash flow available for other purposes,
      including working capital and capital expenditures;

    - limiting Affymetrix' flexibility in planning for, or reacting to, changes
      in its business and the industry in which it competes; or

    - placing Affymetrix at a possible competitive disadvantage compared to less
      leveraged competitors and competitors that have better access to capital
      resources.

THE NOTES ARE SUBORDINATED TO ALL OTHER SENIOR DEBT.

    The notes are unsecured and subordinated in right of payment to all of
Affymetrix' existing and future senior indebtedness, as defined in the
indenture, dated as of September 22, 1999. As a result, in the event of
bankruptcy, liquidation or reorganization or upon acceleration of the notes due
to an event of default, as defined below and in specific other events,
Affymetrix' assets will be available to pay obligations on the notes only after
all senior indebtedness has been paid in full in cash or other payment
satisfactory to the holders of senior indebtedness. There may not be sufficient
assets remaining to pay amounts due on any or all of the notes then outstanding.
The notes are also effectively subordinated to the liabilities, including trade
payables, of Affymetrix' subsidiary. The indenture does not prohibit or limit
the incurrence of senior indebtedness or the incurrence of other indebtedness
and other liabilities by Affymetrix or its subsidiary. The incurrence of
additional indebtedness and other liabilities by Affymetrix or its subsidiary
could adversely affect Affymetrix' ability to pay obligations on the notes. As
of September 30, 1999, Affymetrix had approximately $327,000 of indebtedness
outstanding that would have constituted senior indebtedness. As of
September 30, 1999, Affymetrix' subsidiary had no material indebtedness or other
liabilities. Affymetrix anticipates that from time to time it will incur
additional indebtedness, including senior indebtedness.

WE MAY BE UNABLE TO REPURCHASE THE NOTES.

    At maturity, the entire outstanding principal amount of the notes will
become due and payable by Affymetrix. In addition, in the event of a Change in
Control, each holder of notes will have the right, at the holder's option, to
require Affymetrix to purchase all or any part of such holder's notes.
Affymetrix cannot assure you that it will have sufficient financial resources or
will be able to arrange financing to pay the principal amount or the purchase
price of such notes.

                                       4
<PAGE>
    Under the terms of the indenture, we may elect, if we meet certain
conditions, to pay the purchase price with shares of common stock; such payment
in common stock would have a dilutive effect on holders of our common stock and
could cause the market price of our common stock to decline.

    Our ability to purchase the notes in the event of a Change in Control,
whether in cash or in common stock, may be limited by law, the indenture and the
terms of other agreements relating to borrowings that constitute senior
indebtedness, as such indebtedness or agreements may be entered into, replaced,
supplemented or amended at any time or from time to time. Affymetrix may be
required to refinance its senior indebtedness in order to make any such payment.
Affymetrix may not have the financial ability to purchase the notes in the event
payment of its senior indebtedness is accelerated.

    The term "Change in Control" is limited to certain specified transactions
and may not include other events that might adversely affect Affymetrix'
financial condition or result in a downgrade of the credit rating of the notes,
nor would the requirement that Affymetrix offer to purchase the notes upon a
Change in Control necessarily afford holders of the notes protection in the
event of a highly leveraged transaction, reorganization, merger or similar
transaction. The term "Change in Control" does not apply to transactions in
which 90% of the consideration paid for Affymetrix' common stock in a merger or
similar transactions consists of common stock and in certain other circumstances
where Affymetrix' common stock is trading at a premium over its conversion
price. See "Description of Notes--Certain Rights to Require Purchase of Notes
Upon a Change in Control."

THERE IS NO PUBLIC MARKET FOR THE NOTES AND THERE ARE RESTRICTIONS ON RESALE OF
THE NOTES.

    The notes are currently eligible to trade on the Private Offerings, Resale
and Trading through Automated Linkages (PORTAL-SM-) Market of the Nasdaq Stock
Market. Although the initial purchasers have advised us that they currently
intend to make a market in the notes, they are not obligated to do so and may
discontinue market making activities at any time without notice. Consequently,
we cannot ensure that any market for the notes will develop or, if one does
develop, that it will be maintained. If an active market for the notes fails to
develop or be sustained, the trading price of the notes could be materially and
adversely affected. We do not intend to apply for listing of the notes on any
securities exchange or any automated quotation system.

                 RISKS RELATING TO AFFYMETRIX AND ITS BUSINESS

BECAUSE AFFYMETRIX COMMON STOCK IS EXTREMELY VOLATILE AND DIFFICULT TO PREDICT,
BASED IN PART UPON THE VARIABILITY IN AFFYMETRIX' QUARTERLY RESULTS OF
OPERATIONS, THE MARKET VALUE OF YOUR AFFYMETRIX COMMON STOCK WILL FLUCTUATE
SIGNIFICANTLY AND MAY DECREASE.

    Recently, the stock market and the trading price for Affymetrix common stock
have experienced price fluctuations. Market fluctuations may reduce the market
price of Affymetrix common stock. As a result of any one of the following
factors, some of which are beyond Affymetrix' control, the market value of the
Affymetrix common stock you receive as a result of the merger may be
significantly less than the market value of Affymetrix common stock today:

    - quarterly variations in Affymetrix' operating results;

    - the sale by Affymetrix' principal stockholder, Glaxo Wellcome, plc and its
      affiliates, of all or a portion of their 31% interest;

    - the simultaneous sale by a significant number of former Genetic
      MicroSystems stockholders of Affymetrix common stock shortly after the
      merger of Affymetrix and Genetic MicroSystems;

    - announcements of new commercial products and initiatives either by
      Affymetrix or its collaborative partners or competitors;

    - developments in litigation initiated against Affymetrix or by Affymetrix;

                                       5
<PAGE>
    - developments concerning proprietary rights;

    - technological innovations by Affymetrix and its competitors;

    - new collaborative agreements;

    - announcements of Affymetrix' results of research activities;

    - changes in patent laws;

    - changes in government regulation or new regulatory actions; and

    - fluctuations in the stock market price and volume of traded shares
      generally, especially fluctuations in the traditionally volatile
      technology and biotechnology sectors.

    One important reason for Affymetrix' volatile stock price is the volatility
in its quarterly results of operations, which may fluctuate significantly
period-to-period. These fluctuations depend on a number of factors, including:

    - the volume and timing of orders for GeneChip products;

    - the timing of probe array, instrument and software shipments and
      installations;

    - Affymetrix' manufacturing capabilities;

    - variations in product yields and gross margins;

    - variations in revenue recognized under Affymetrix' supply and
      collaborative agreements, including license fees, product sales, design
      fees, milestones, royalties and other contract revenues;

    - Affymetrix' mix of products sold;

    - the timing of new product introductions by Affymetrix;

    - variations in expenses incurred in connection with the operations of
      Affymetrix' business, including legal fees, manufacturing facility
      start-up costs and capital expenditures;

    - the delay by customers of fourth quarter 1999 orders until after
      January 1, 2000;

    - the introduction of new products by Affymetrix' competitors;

    - the cost and availability of licenses to third-party intellectual property
      associated with Affymetrix' products;

    - market acceptance of the GeneChip products and other potential products;

    - the cost, quality and availability of reagents and components required to
      manufacture or use Affymetrix' products;

    - the price and terms under which Affymetrix is able to license its
      intellectual property to others;

    - changes in commercial and government funding of research using Affymetrix'
      products;

    - regulatory actions; and

    - third-party reimbursement policies.

    Although Affymetrix believes that period-to-period comparisons of
Affymetrix' results of operations are not a good indication of Affymetrix'
future performance, it is likely that in some future quarter or quarters,
Affymetrix' operating results will be below the expectations of public market
analysts or investors and the market price of Affymetrix common stock may fall
significantly.

                                       6
<PAGE>
BECAUSE AFFYMETRIX HAS A LIMITED OPERATING HISTORY AND IS IN THE EARLY STAGES OF
DEVELOPMENT OF COMMERCIAL USES FOR ITS TECHNOLOGY, AFFYMETRIX CANNOT ASSURE YOU
THAT IT WILL EVENTUALLY DEVELOP A COMMERCIALLY SUCCESSFUL PRODUCT.

    For the most part, Affymetrix' technologies are still in the early stages of
development, and Affymetrix has just begun to incorporate its technologies into
commercial products. Affymetrix needs to make significant investments to ensure
Affymetrix' products perform correctly and are cost-effective as well as to
obtain additional regulatory approvals to sell its product for purposes other
than research use. Even if Affymetrix develops its products for commercial use
and obtains all necessary regulatory approvals, it may not be able to develop
products that:

    - are accepted by the research, diagnostic or other marketplaces;

    - are accurate and effective;

    - meet applicable regulatory standards in a timely manner;

    - are protected from competition by others;

    - do not infringe the intellectual proprietary rights of others;

    - can be manufactured in sufficient quantities or at a reasonable cost; or

    - can be marketed successfully.

UNLESS AFFYMETRIX DECREASES VARIABILITY IN ITS MANUFACTURING YIELDS, INCREASES
ITS MANUFACTURING CAPACITY AND RESOLVES ITS OTHER MANUFACTURING PROBLEMS, IT MAY
BE UNABLE TO MANUFACTURE PRODUCTS CONSISTENTLY ON A TIMELY BASIS THAT MEET
CUSTOMER PERFORMANCE EXPECTATIONS, WHICH COULD HARM ITS RELATIONSHIP WITH ITS
CUSTOMERS AND CAUSE DEMAND FOR ITS PRODUCTS TO DECLINE AND HARM ITS FINANCIAL
PERFORMANCE.

    Affymetrix is currently manufacturing limited quantities of probe arrays for
internal and collaborative purposes and for sale to the research market in two
manufacturing facilities, one located in Sunnyvale, California and the other in
West Sacramento, California. The actual number of probe arrays Affymetrix is
able to sell or use depends on the utilization of the production capacity at
these facilities, the yield of probe arrays that pass quality control testing
and the number of probe arrays manufactured on each probe array wafer. Portions
of the production capacity at these facilities are also limited to only some
types of probe arrays. Affymetrix has experienced and continues to experience
significant variability in the manufacturing yield of its GeneChip products
which has reduced, and is expected to continue to reduce, its gross margins and
revenues. Affymetrix has also experienced, and anticipates that it will continue
to experience, difficulties in meeting anticipated customer, collaborator and
internal demand for some of its probe array products. Affymetrix' inability to
deliver products in a timely manner could seriously harm its relationship with
its customers, delay introduction of new products and cause demand for its
products to decline.

    Because Affymetrix has a limited manufacturing history, it does not fully
understand all of the factors that affect its manufacturing processes, which may
not easily allow for production in larger volumes. As a result, manufacturing
and quality control problems have arisen and Affymetrix expects them to continue
to arise as Affymetrix attempts to increase the production rate at its
manufacturing facilities. Affymetrix may not be able to increase production
rates at these facilities in a timely and cost-effective manner or at
commercially reasonable cost.

    Moreover, the Sunnyvale, California manufacturing facility is located in an
earthquake-prone area, and the West Sacramento facility is susceptible to
flooding. Although Affymetrix has two manufacturing facilities, which Affymetrix
expects will mitigate risk when the West Sacramento facility becomes fully
operational and capacity is increased at that facility, Affymetrix could be
unable to manufacture products

                                       7
<PAGE>
for sale or its capacity could be significantly decreased if one of these
facilities is damaged until that damaged facility is replaced or restored to
operation.

BECAUSE AFFYMETRIX' QUALITY CONTROL PROCEDURES MAY NOT BE FULLY DEVELOPED TO
ENSURE PROPER PERFORMANCE OF ITS PRODUCTS, AFFYMETRIX' CUSTOMERS MAY RECEIVE
UNDERPERFORMING PRODUCTS AND MAY DECIDE TO SWITCH TO A NEW SUPPLIER.

    The GeneChip products are produced in an innovative and complicated
manufacturing process. Unlike semiconductor companies, Affymetrix can test only
a portion of the products it produces due to the unique nature of its products.
It is possible that Affymetrix may not identify a probe array that does not meet
all of Affymetrix' performance specifications before it is shipped. Further,
after the probe arrays are shipped, a customer may test only selected probes.
Due to the complexity and limited operating history of these products,
Affymetrix and its customers have experienced technical problems and anticipate
that additional technical problems will occur and be discovered as more GeneChip
systems are placed into operation. If Affymetrix is unable to deliver products
consistently to its customers that meet their performance expectations, demand
for Affymetrix' products will decline.

IF AFFYMETRIX FAILS TO OBTAIN, ENFORCE, DEFEND OR MAINTAIN ITS INTELLECTUAL
PROPERTY RIGHTS, OR IF IT NEEDS A LICENSE TO INTELLECTUAL PROPERTY TO CONTINUE
ITS BUSINESS, ITS BUSINESS MAY BE IRREPARABLY HARMED.

    Affymetrix is involved in significant litigation in which third parties
assert that Affymetrix is infringing their intellectual property. In addition,
other parties have patents that Affymetrix believes may be asserted against
Affymetrix.

    If Affymetrix, its partners or its customers must obtain a license to
continue to manufacture, market or use its current or future products and
processes, Affymetrix, its partners or its customers may not be able to obtain
that license on commercially acceptable terms, if at all. For example, if Hyseq
or Oxford Gene Technology were successful in their lawsuits against Affymetrix,
Affymetrix believes neither company would grant Affymetrix a license on
commercially reasonable terms, if at all. Affymetrix may also have to negotiate
a license with third parties, either because it believes it may be infringing
another party's intellectual property or because it wishes to expand its product
line using another party's technology. Affymetrix may not be able to obtain
these licenses on commercially acceptable terms, if at all.

    Affymetrix' failure to enforce successfully its intellectual property rights
would remove a legal obstacle to competitors in designing probe array systems
with similar competitive advantages to Affymetrix' GeneChip technology.
Affymetrix is currently involved in significant litigation and/or oppositions
with Hyseq, Oxford Gene Technology, Incyte, Synteni, Multilyte and ProtoGene
concerning Affymetrix' intellectual property which consume and will continue to
consume substantial financial and managerial resources. Further, because of the
substantial amount of discovery required in connection with any litigation,
there is a risk that disclosure could compromise confidential information. In
addition, patent law relating to the scope of claims in Affymetrix' technology
fields is still evolving and the extent of future protection for Affymetrix'
proprietary rights is uncertain.

    The patent positions of pharmaceutical and biotechnology companies are
generally uncertain and involve complex legal and factual questions. Affymetrix
believes that there will continue to be significant litigation in the industry
regarding patent and other intellectual property rights. As a result, Affymetrix
cannot guarantee:

    - that any of Affymetrix' pending patent applications will result in issued
      patents;

    - that Affymetrix will develop additional technologies that are patentable;

    - that any patents issued to Affymetrix or its strategic partners will
      provide a basis for commercially viable products;

                                       8
<PAGE>
    - that third parties will not challenge any patents issued to Affymetrix or
      its strategic partners;

    - that any patents issued to Affymetrix or its strategic partners will not
      be challenged by third parties; or

    - that the patents of others will not have a negative impact on Affymetrix'
      ability to do business.

    Others may independently develop similar or alternative technologies,
duplicate any of Affymetrix' technologies, or design around or invalidate
Affymetrix' patented technologies. In addition, Affymetrix has incurred and
expects to continue to incur substantial costs to bring litigation and to defend
against the patent suits brought by third parties. Administrative proceedings,
such as oppositions or interferences, in both the United States Patent Office or
any foreign patent office could also substantially reduce the scope of
Affymetrix' patent protection as well as result in the expenditure of
substantial funds in legal fees.

BECAUSE THE MARKETS IN WHICH AFFYMETRIX OPERATES ARE HIGHLY COMPETITIVE AND
RAPIDLY CHANGING, AFFYMETRIX MUST CONTINUE TO DEVELOP AND INTRODUCE NEW PRODUCTS
TO COMPETE SUCCESSFULLY AGAINST NEW ENTRANTS AND ESTABLISHED COMPANIES WITH
GREATER RESOURCES.

    Affymetrix competes in markets that are new, intensely competitive, highly
fragmented and rapidly changing. Affymetrix has experienced and expects to
continue to experience increased competition from current and potential
competitors, many of which have significantly greater financial, technical,
marketing and other resources.

    A large number of publicly traded and privately held companies, including
Applied Biosystems division of Perkin-Elmer, Amersham Pharmacia Biotech,
CuraGen, Gene Logic, General Scanning, Corning, Genome Solutions,
Hewlett-Packard, Hitachi, Incyte/Synteni, Illumina, Lynx and Motorola, also are
developing or have developed DNA probe based tests or other products and
services, some of which may be competitive with Affymetrix' products.

    The failure of Affymetrix to develop the enhancements to its technology or
manufacturing equipment necessary to compete successfully with newly emerging
technologies, or to develop products based on these technologies, will harm
Affymetrix' business.

    Currently, Affymetrix' principal competition comes from existing DNA probe
array and other technologies that are used to perform many of the same functions
for which Affymetrix markets its GeneChip products. In order to compete against
existing and newly developed technologies and maintain pricing and gross
margins, Affymetrix will need to be successful in demonstrating to potential
customers that the GeneChip products provide improved performance and
capabilities and in asserting Affymetrix patents in the DNA probe array field.

    Affymetrix' competitors may be able to respond more quickly to new or
emerging technologies and changes in customer requirements than Affymetrix can.
In addition, current and potential competitors have greater name recognition,
more extensive customer bases and access to proprietary genetic content.

BECAUSE AFFYMETRIX DEPENDS ON A LIMITED NUMBER OF SUPPLIERS, IT MAY NOT BE ABLE
TO SHIP PRODUCTS ON TIME IF IT IS UNABLE TO OBTAIN AN ADEQUATE SUPPLY OF
MANUFACTURING EQUIPMENT, RAW MATERIALS AND PRODUCT COMPONENTS FROM THOSE
SUPPLIERS ON A TIMELY BASIS, WHICH COULD REDUCE DEMAND FOR ITS PRODUCTS.

    Affymetrix relies on Hewlett-Packard to manufacture, install and service its
scanners and on Enzo to manufacture certain reagents used with probe arrays and
various labeling kits needed to process samples. Key parts of the GeneChip
product line, as well as various equipment and raw materials used in the
synthesis of probe arrays, are currently available only from a single source or
a limited number of sources. In addition, components of Affymetrix'
manufacturing equipment are available from one of only a few suppliers.
Affymetrix cannot assure you that manufacturing equipment, scanners or other
components of

                                       9
<PAGE>
the GeneChip product will be available in a timely fashion and in sufficient
quantities under acceptable terms. Even if alternative sources of supply are
available, it could be time consuming and expensive for Affymetrix to qualify
new vendors. In addition, Affymetrix is dependent on its vendors to provide
components of appropriate quality and reliability and to meet applicable
regulatory requirements. Consequently, in the event that supplies from these
vendors were delayed or interrupted for any reason, Affymetrix could be delayed
in its ability to develop and deliver products to its customers.

IF AFFYMETRIX IS UNABLE TO MAINTAIN ITS RELATIONSHIPS WITH COLLABORATIVE
PARTNERS, AFFYMETRIX MAY HAVE DIFFICULTY SELLING ITS PRODUCTS AND SERVICES.

    Affymetrix believes that its success in penetrating its target markets
depends in part on Affymetrix' ability to develop and maintain collaborative
relationships with key pharmaceutical, diagnostic, biotechnology,
bioinformatics, analytical instrument and reagent companies as well as with
academic researchers, all in an effort to help develop, test, manufacture, sell
and service Affymetrix' GeneChip technology. Affymetrix has significant
relationships with Hewlett-Packard, bioMerieux, Amersham Pharmacia Biotech KK
and Roche Molecular Systems, and Affymetrix has entered into a consortium with
the Whitehead Institute, Millennium Pharmaceuticals and Bristol-Myers Squibb.
Affymetrix has received a material portion of its revenue since inception from
these and other collaborative partners. Affymetrix also intends to enter into
collaborative arrangements with other companies to expand Affymetrix'
operations, apply its technology, and sell potential future products.
Affymetrix' present or future collaborative partners may not be able to perform
their obligations as expected or devote sufficient resources to the development,
clinical testing, supply or marketing of Affymetrix' potential products
developed under these collaborations. Moreover, any of the following
developments could impact Affymetrix' business, financial condition and results
of operations:

    - one of Affymetrix' partners develops technologies or components
      competitive with Affymetrix' GeneChip products;

    - Affymetrix' existing collaborations preclude it from entering into
      additional arrangements;

    - failure of Affymetrix' partners to obtain timely regulatory approvals;

    - premature termination of an agreement;

    - one of Affymetrix' partners' failure to devote sufficient resources to the
      development and sale of its products; or

    - inability of one of Affymetrix' partners to supply products to it.

    In addition, Affymetrix' agreements with its collaborators may have
provisions that allow for termination or give rise to disputes regarding the
rights and obligations of the parties. These and other possible disagreements
could lead to termination of the agreement or delays in collaborative research,
development, supply or commercialization of certain products, or could require
or result in litigation or arbitration. Any such delay, litigation or
arbitration could impact Affymetrix' financial condition. Any of Affymetrix'
collaborations may prove to be unsuccessful. Likewise, Affymetrix may not be
able to negotiate future collaborative arrangements on acceptable terms, if at
all.

UNLESS AFFYMETRIX DEVELOPS AND MARKETS PROFITABLE COMMERCIAL PRODUCTS, IT WILL
CONTINUE TO EXPERIENCE SIGNIFICANT OPERATING LOSSES.

    Affymetrix has experienced net losses of $2 million to $25 million per year
since its inception and has an accumulated deficit of approximately
$112.8 million as of September 30, 1999. Moreover, Affymetrix expects to incur
substantial additional operating losses as a result of increases in expenses for
manufacturing, marketing and sales, research and product development and general
and administrative costs. If

                                       10
<PAGE>
Affymetrix is unable to achieve, among other things, the goals set forth below,
it may never achieve profitability:

    - achieve consistently acceptable manufacturing yields;

    - develop products that the marketplace accepts;

    - create a product mix that is appealing to pharmaceutical and biotechnology
      companies, academic research centers and clinical reference laboratories;

    - enter into supply agreements with customers desiring to use Affymetrix'
      products;

    - establish its commercial manufacturing capability for DNA probe arrays;

    - cost-effectively manufacture components of its GeneChip product line;

    - avoid infringing on the intellectual property rights of others;

    - enforce Affymetrix' intellectual property rights against others;

    - establish sales and distribution capabilities cost-effectively;

    - develop its marketing capabilities cost-effectively;

    - obtain necessary regulatory approvals; and

    - hire and retain qualified key personnel.

AFFYMETRIX HAS LIMITED SALES, MARKETING AND TECHNICAL SUPPORT EXPERIENCE, WHICH
MAY HURT ITS EFFORTS AT SELLING ITS PRODUCTS.

    Affymetrix has expanded the distribution of its products in recent years.
This expansion has placed new and increased demands on its direct sales force
and technical and sales support staff, including accounting controls. Although
Affymetrix invests significant resources to expand its direct sales force and
its technical and support staff, only a limited number of qualified personnel
are available in these areas. Therefore, Affymetrix may not be able to expand
its direct sales force and technical support staff as necessary to support its
growing operations. Affymetrix has also entered into a non-exclusive
distribution agreement with Amersham Pharmacia Biotech KK covering Japan and a
service agreement with Hewlett-Packard for its GeneArray scanner. Affymetrix'
existing organization and relationships may not be sufficient and Affymetrix may
have to expand its organization and enter into additional collaboration or
distribution arrangements to sell its products both inside and outside the
United States. Affymetrix cannot assure you that:

    - Affymetrix will be able to establish a sufficiently sized sales, marketing
      or technical support organization;

    - Amersham Pharmacia Biotech KK will be successful in distributing
      Affymetrix' products;

    - Amersham Pharmacia Biotech KK will not sell competitive products in Japan;

    - Hewlett-Packard will be successful in servicing Affymetrix' instruments
      and not become its competitor; or

    - Affymetrix will be able to establish additional collaborative or
      distribution arrangements to sell, market and service its products.

                                       11
<PAGE>
THE LOSS OF A KEY CUSTOMER COULD SUBSTANTIALLY REDUCE AFFYMETRIX' REVENUES AND
BE PERCEIVED AS A LOSS OF MOMENTUM IN ITS BUSINESS.

    Affymetrix believes that the sales cycle for the GeneChip products will be
lengthy due to the need to educate potential customers about its
characteristics. As a result, Affymetrix' customers are concentrated in a small
number of pharmaceutical and biotechnology companies, academic research centers
and clinical reference laboratories. Affymetrix expects that a small number of
customers will continue to account for a substantial portion of revenues for the
foreseeable future. If Affymetrix loses a major customer, Affymetrix' revenues
may be substantially reduced and investors may perceive this as a loss of
momentum in Affymetrix' business. Moreover, if consideration in the
pharmaceutical and biotechnology industries continues, Affymetrix' current and
potential customers could decrease or slow aggregate sales of its technology and
shrink its target market.

    Affymetrix' dependence on sales to a few customers may also strengthen the
negotiating position of its potential customers, which, in turn, could reduce
the sales price of the GeneChip products and reduce Affymetrix' revenues.

AFFYMETRIX' BUSINESS COULD SUFFER IF AFFYMETRIX CANNOT INTEGRATE OR FULLY
REALIZE IN A TIMELY FASHION THE COST SAVINGS AND OTHER BENEFITS IT EXPECTS TO
OCCUR AS A CONSEQUENCE OF ACQUISITIONS, INCLUDING THE ANTICIPATED ACQUISITION OF
GENETIC MICROSYSTEMS.

    Affymetrix may not be able to integrate successfully and profitably manage
acquired entities, such as Genetic MicroSystems, without incurring substantial
costs, delays or other financial or operational difficulties. In particular,
there are many things relating to the integration and management of Genetic
MicroSystems that could go wrong and harm the financial condition of the
combined company. Some of these things include:

    - diversion of management's attention;

    - the failure to realize fully in a timely fashion the enhanced cost
      savings, selling opportunities, development, marketing and manufacturing
      benefits Affymetrix expects will occur after the merger; and

    - risks associated with unanticipated events or liabilities.

    Although Affymetrix has conducted what it believes to be a prudent level of
review regarding the operational condition of Genetic MicroSystems, it cannot
predict the full range of integration-related problems which may occur.

BECAUSE AFFYMETRIX' BUSINESS IS HIGHLY DEPENDENT ON KEY EXECUTIVES AND
SCIENTISTS, AFFYMETRIX' INABILITY TO RECRUIT AND RETAIN THESE PERSONNEL COULD
HINDER ITS BUSINESS EXPANSION PLANS.

    Affymetrix is highly dependent on its executive officers and its senior
scientists and engineers, including its scientific advisors. The loss of
services of any of these persons could have a negative impact on Affymetrix'
product development and marketing efforts. In addition, research, product
development and sales will require additional skilled personnel in areas such as
bioinformatics, organic chemistry, information services, regulatory affairs,
manufacturing, sales, marketing and technical support.

    There is a shortage of skilled personnel, which is likely to continue for
some time. As a result, competition for these people, particularly for employees
with technical expertise, is intense and the turnover rate for these people is
high. If Affymetrix is unable to hire, train and retain a sufficient number of
qualified employees, it could hinder the planned expansion of its business.

    In addition, Affymetrix relies on its scientific advisors and consultants to
assist it in formulating its research, development and commercialization
strategy. All of the scientific advisors and consultants are engaged by
employers other than Affymetrix and have commitments to other entities that may
limit their

                                       12
<PAGE>
availability to Affymetrix. Some of Affymetrix' scientific advisors and
consultants also consult for companies that may be its competitors.

SERIOUS ETHICAL, LEGAL AND SOCIAL IMPLICATIONS SURROUNDING GENETIC TESTING MAY
HARM THE MARKET ACCEPTANCE OF AFFYMETRIX' PRODUCTS OR MAY CAUSE GOVERNMENTAL
AUTHORITIES TO SEVERELY RESTRICT THE USE OF GENETIC TESTS, WHICH COULD SERIOUSLY
REDUCE THE MARKET FOR AFFYMETRIX' PRODUCTS.

    The genetic tests under development by Affymetrix have given rise to some
difficult issues, including:

    - genetic tests may be subject to ethical concerns or reluctance to
      administer or pay for tests for conditions that are not treatable; and

    - specific gene-based diagnostic tests could encounter public resistance,
      resulting in societal and governmental concerns regarding genetic testing
      in general.

    The prospect of broadly available genetic testing has also raised issues
regarding the appropriate utilization and the confidentiality of information
provided by this testing.

    Governmental authorities could limit the use of genetic testing or prohibit
it under some conditions. These restrictions would reduce the market for
Affymetrix' products. Moreover, ethical concerns about genetic testing may
seriously affect market acceptance of Affymetrix' GeneChip product or result in
legislative restrictions on the use of Affymetrix' products in some countries.

REDUCTIONS IN GOVERNMENT FUNDING OF RESEARCH INSTITUTIONS COULD REDUCE
AFFYMETRIX' REVENUES.

    Affymetrix sells a significant portion of its products for research use to
universities, government research laboratories, private foundations and other
institutions whose funding is dependent upon grants from government agencies,
such as the National Institute of Health. The government, however, may
significantly reduce research funding in the future. Any such reduction may harm
Affymetrix' existing and prospective research customers' ability to purchase
Affymetrix' products for research use.

IF AFFYMETRIX CANNOT COMPLY WITH GOVERNMENT REGULATIONS OR AFFYMETRIX
EXPERIENCES DELAYS IN GETTING APPROVAL FROM GOVERNMENTAL AGENCIES OR
GOVERNMENTAL AGENCIES RESTRICT AFFYMETRIX' ABILITY TO MARKET ITS PRODUCTS,
AFFYMETRIX WILL BE UNABLE TO SELL A COMMERCIAL PRODUCT.

    Affymetrix must comply with the FDA's regulations for the sale of
"analyte-specific reagents," as well as other standards prescribed by various
federal, state and local regulatory agencies in the United States and other
countries. Although Affymetrix has registered the manufacturing sites for its
arrays as ASRs with the FDA and its products are listed with the FDA, Affymetrix
cannot guarantee that it will be able to comply with the regulations at
reasonable costs.

    In addition, many of Affymetrix' future products, including its diagnostic
products, will be regulated as medical devices when Affymetrix or its partners
begin selling their products commercially for non-research uses and will be
subject to further approval by the FDA or foreign agencies and compliance with
the ISO quality standards instituted by the International Organization for
Standardization for sales in Europe. Affymetrix, however, has not filed any
applications to market commercially its products as medical devices with the FDA
or any foreign agency. Delays in the application or approval process may cause
Affymetrix to introduce its products into the market later than anticipated. Any
failure to obtain regulatory approval, restrictions on Affymetrix' ability to
market its products, or delays in the introduction of Affymetrix' products to
the market could harm its business.

    Moreover, the FDA and state agencies inspect medical device manufacturers
periodically. If the FDA believes that a company is not in compliance with
applicable laws or regulations, it can take any number of actions, including
detaining or seizing products and assessing civil and criminal penalties against
Affymetrix, its officers or its employees.

                                       13
<PAGE>
    Medical device laws and regulations are also in effect in many of the
countries where Affymetrix may do business. These laws and regulations range
from comprehensive device approval requirements for some or all of Affymetrix'
medical device products to requests for product data or certifications. The
number and scope of these requirements are increasing. Affymetrix may not be
able to obtain regulatory approvals in these countries or it may be required to
incur significant costs in obtaining or maintaining its foreign regulatory
approvals. In addition, the export of certain of Affymetrix' products which have
not yet been cleared for domestic commercial distribution may be subject to FDA
export restrictions. Any failure to obtain product approvals in a timely fashion
or to comply with state or foreign medical device laws and regulations may
prevent Affymetrix from marketing its products.

    Affymetrix is also subject to numerous environmental and safety laws and
regulations, including those governing the use, storage and disposal of
hazardous and biological materials, and construction of new facilities.
Affymetrix may not be able to obtain the necessary permits to operate new
facilities or the cost of compliance may be very high.

AFFYMETRIX' BUSINESS COULD BE HARMED IF AFFYMETRIX' PRODUCTS OR THE PRODUCTS
UPON WHICH IT DEPENDS MALFUNCTION OR BECOME UNAVAILABLE BECAUSE OF YEAR 2000
PROBLEMS.

    Affymetrix is continuing to assess or has assessed the potential impact of
the year 2000 computer problem on its products, including GeneChip products and
software, information systems, embedded systems, including computers used in its
manufacturing process, and on the ability of some third parties to supply
critical materials and services as well as the readiness of some customers.
Affymetrix completed the assessment of its products, computer systems, embedded
systems, some third party suppliers and major customers in the second quarter of
1999, and plans to take necessary remediation action by the end of 1999. While
Affymetrix does not anticipate a material business interruption to result from
the year 2000 problem, Affymetrix may experience a business interruption if any
of Affymetrix' products, information systems, embedded systems, key third party
suppliers and services providers and major customers are not year 2000 ready. In
addition, Affymetrix' sales in the last quarter of 1999 may be reduced if
customers defer purchases due to year 2000 concerns. Affymetrix has implemented
a year 2000 contingency plan that involves purchasing and building inventory
over the remainder of 1999 so that it will be able to continue to operate in the
event of a modest and short-term supply shortage resulting from any year 2000
problems experienced by its suppliers.

AFFYMETRIX' EFFORTS TO INCREASE ITS PRESENCE IN MARKETS OUTSIDE OF THE UNITED
STATES MAY BE UNSUCCESSFUL AND COULD RESULT IN LOSSES.

    Affymetrix intends to expand its international presence in order to increase
its export sales. Export sales to international customers entail a number of
risks, each of which could reduce Affymetrix' revenues. These risks include:

    - unexpected changes in, or impositions of, legislative or regulatory
      requirements;

    - delays resulting from difficulty in obtaining export licences for certain
      technology, tariffs, quotas and other trade barriers and restrictions;

    - longer payment cycles and greater difficulty in accounts receivable
      collection;

    - potentially adverse taxes;

    - currency exchange fluctuations;

    - the burdens of complying with a variety of foreign laws; and

    - other factors beyond Affymetrix' control.

                                       14
<PAGE>
RESTRICTIVE REIMBURSEMENT POLICIES BY HEALTH CARE ORGANIZATIONS COULD REDUCE
AFFYMETRIX' REVENUES.

    Affymetrix' ability to sell certain products and services successfully may
depend on the extent to which Affymetrix is able to secure reimbursement from
government authorities, such as Medicare and Medicaid, private health insurers,
and other organizations, such as health maintenance organizations. These third-
party payors are increasingly likely to challenge the prices charged for health
care products and services. The cumulative effect of the trend towards managed
health care in the United States, legislative proposals to reform health care or
reduce government insurance programs, and the concurrent growth of organizations
such as HMOs, which could control or significantly influence the purchase of
health care products and services, may result in lower prices for health care
products and services sold by Affymetrix, its customers and its collaborative
partners. This reduction in turn could reduce the amount of Affymetrix' future
revenues or royalty payments that may be due to it. The lower prices could also
harm Affymetrix' profits and the profits of its customers and collaborative
partners. As a result, pharmaceutical, diagnostic and biotechnology companies
may choose to reduce or eliminate certain research and development programs that
utilize Affymetrix' products. A reduction of Affymetrix' revenues or royalty
payments or the reduction or cancellation of research programs that utilize
Affymetrix' products could seriously harm its business, financial condition and
results of operations.

BECAUSE GLAXO WELLCOME OWNS A SUBSTANTIAL PORTION OF AFFYMETRIX' OUTSTANDING
CAPITAL STOCK, IT MAY BE ABLE TO INFLUENCE THE OUTCOME OF STOCKHOLDER VOTES.

    Glaxo Wellcome, plc and its affiliates currently beneficially own
approximately 31% of the outstanding Affymetrix common stock. Although
Affymetrix has executed a governance agreement with Glaxo, Glaxo nevertheless
may be able to influence the outcome of stockholder votes, including votes
concerning the election of directors, adoption of amendments to Affymetrix'
certificate of incorporation and bylaws and approval of mergers and other
significant corporate transactions.

AFFYMETRIX HAS VARIOUS MECHANISMS IN PLACE TO DISCOURAGE TAKEOVER ATTEMPTS WHICH
MAY DISCOURAGE, DELAY OR PREVENT A CHANGE IN CONTROL THAT A STOCKHOLDER MAY
CONSIDER FAVORABLE.

    Affymetrix adopted a stockholder rights plan and change of control policy.
The purpose of the stockholder rights plan is to allow Affymetrix and its board
of directors an opportunity to deal responsibly with parties that attempt to
gain a control position in Affymetrix without the approval of the board of
directors. The purpose of the change of control policy is to ensure that
Affymetrix' employees are treated fairly in the event of a change of control.
Affymetrix' stockholder rights plan and change of control policy may discourage,
delay or prevent a change in control of Affymetrix that a stockholder may
consider favorable.

    In addition, certain provisions of Affymetrix' certificate of incorporation
and bylaws may discourage, delay or prevent a change in control of it that a
stockholder may consider favorable. These provisions include:

    - authorizing the issuance of "blank check" preferred stock;

    - prohibiting cumulative voting in the election of directors;

    - requiring super-majority voting to effect certain amendments to
      Affymetrix' certificate of incorporation and bylaws;

    - limiting the persons who may call special meetings of stockholders;

    - prohibiting stockholder action by written consent; and

    - establishing advance notice requirements for nominations for election to
      the board of directors or for proposing matters that can be acted upon by
      stockholders at stockholder meetings.

                                       15
<PAGE>
    In addition, relevant provisions of Delaware law and Affymetrix' stock
incentive plans may also discourage, delay or prevent a change in control.

IF AFFYMETRIX IS FOUND LIABLE FOR A PRODUCT LIABILITY CLAIM, IT MAY NOT HAVE
  ADEQUATE INSURANCE TO PAY THAT CLAIM, WHICH WILL HARM AFFYMETRIX' FINANCIAL
  CONDITION.

    Affymetrix' business exposes it to potential product liability claims that
are inherent in the testing, manufacturing, marketing and sale of human
diagnostic and therapeutic products. Affymetrix intends to acquire additional
insurance, should it be desirable, for clinical liability risks. Affymetrix may
not be able to obtain this insurance or general product liability insurance on
acceptable terms or at reasonable costs or this insurance may not be in
sufficient amounts to provide adequate coverage against potential liabilities.

BECAUSE THE MARKET PRICE OF AFFYMETRIX COMMON STOCK IS EXTREMELY VOLATILE,
  AFFYMETRIX MAY BE AT RISK OF SECURITIES CLASS ACTION LITIGATION.

    In the past, securities class action litigation has often been brought
against a company following periods of volatility in the market price of its
securities. Due to the potential volatility of its stock price, Affymetrix may
be the target of this type of litigation in the future. Securities litigation
could result in substantial costs and divert management's attention and
resources.

                                       16
<PAGE>
                           FORWARD-LOOKING STATEMENTS

    All statements in this prospectus that are not historical are
forward-looking statements within the meaning of Section 21E of the Securities
Exchange Act of 1934 (the "Exchange Act"), including statements regarding our
"expectations," "beliefs," "hopes," "intentions," "strategies" or the like.
These statements are based on our management's current expectations and are
subject to a number of factors and uncertainties that could cause actual results
to differ materially from those described in the forward-looking statements. We
caution investors that there can be no assurance that actual results or business
conditions will not differ materially from those projected or suggested in these
forward-looking statements as a result of various factors, including but not
limited to, the risk factors contained in this prospectus. We expressly disclaim
any obligation or undertaking to release publicly any updates or revisions to
any forward-looking statements contained in this prospectus to reflect any
change in our expectations with regard to these statements or any change in
events, conditions or circumstances on which any of these statements is based.

                      WHERE YOU CAN FIND MORE INFORMATION

    We file annual, quarterly and special reports, proxy statements and other
information with the SEC under the Exchange Act. The Exchange Act file number
for our SEC filings is 0-28218. You may read and copy any document we file at
the following SEC public reference rooms:

<TABLE>
<S>                            <C>                            <C>
   450 Fifth Street, N.W.         500 West Madison Street         7 World Trade Center
         Room 1024                      14th Floor                     Suite 1300
   Washington, D.C. 20549         Chicago, Illinois 60661       New York, New York 10048
</TABLE>

    You may obtain information on the operation of the public reference room in
Washington, D.C. by calling the SEC at 1-800-SEC-0330.

    We file information electronically with the SEC. Our SEC filings are
available from the SEC's Internet site at http://www.sec.gov, which contains
reports, proxy and information statements and other information regarding
issuers that file electronically.

    Our common stock is listed on the Nasdaq National Market under the symbol
"AFFX." You may read and copy our SEC filings and other information at the
offices of Nasdaq Operations, 1735 K Street, N.W., Washington, D.C. 20006.

    Except as described under "Incorporation by Reference," the information on
file with the SEC and the Nasdaq National Market does not constitute part of
this prospectus.

                           INCORPORATION BY REFERENCE

    The SEC allows us to "incorporate by reference" certain documents we file
with it, which means that we can disclose important information to you by
referring you to those documents. The information in the documents incorporated
by reference is considered to be part of this prospectus. However, to the extent
the information contained in this prospectus is inconsistent with information
previously filed with the SEC, the information contained in this prospectus
supersedes this incorporated information. Information in documents that we file
later with the SEC will automatically update and supersede information included
or incorporated by reference in this prospectus. We incorporate by reference the
documents listed below and any future filings we will make with the SEC under
Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act:

    - Form 8-A filed on October 16, 1998;

    - Annual Report on Form 10-K for the year ended December 31, 1998;

    - Current Reports on Form 8-K filed on April 1, 1999 and September 28, 1999;

    - Definitive Proxy Statement on Schedule 14A filed on April 29, 1999;

    - Form S-8 filed on August 18, 1999; and

                                       17
<PAGE>
    - Quarterly Reports on Form 10-Q for the quarters ended March 31, 1999,
      June 30, 1999, and September 30, 1999.

    Upon written or oral request, we will provide at no cost to each person to
whom a prospectus is delivered, including any beneficial owner, a copy of any
and all of the information that has been incorporated by reference in this
prospectus. To request a copy of any or all of these documents, you should write
or telephone us at: 3380 Central Expressway, Santa Clara, California 95051,
(408) 731-5000, Attention: Senior Vice President and General Counsel.

                                       18
<PAGE>
                                USE OF PROCEEDS

    We will not receive any proceeds from the sale of the notes or the shares of
common stock offered by this prospectus. See "Selling Security Holders."

                       RATIO OF EARNINGS TO FIXED CHARGES

<TABLE>
<CAPTION>
                                                                                   NINE MONTHS ENDED
                                     FOR THE YEARS ENDED DECEMBER 31,                SEPTEMBER 30,
                           ----------------------------------------------------   -------------------
                             1998       1997       1996       1995       1994       1999       1998
                           --------   --------   --------   --------   --------   --------   --------
<S>                        <C>        <C>        <C>        <C>        <C>        <C>        <C>
Deficiency of earnings
  available to cover
  fixed charges(1).......  $(25,451)  $(22,526)  $(12,227)  $(10,747)  $(9,680)   $(20,100)  $(18,239)
</TABLE>

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

(1) Earnings consist of net loss available to common stockholders. Fixed charges
    consist of interest expense, including amortization of debt issuance costs,
    and that portion of rental expense we believe to be representative of
    interest.

                                       19
<PAGE>
                              DESCRIPTION OF NOTES

    THE NOTES WERE ISSUED UNDER A CONTRACT CALLED THE "INDENTURE," DATED AS OF
SEPTEMBER 22, 1999, BETWEEN US AND THE BANK OF NEW YORK, AS TRUSTEE (THE
"TRUSTEE"). THE FOLLOWING DESCRIPTION IS ONLY A SUMMARY OF THE MATERIAL
PROVISIONS OF THE INDENTURE, THE NOTES AND THE REGISTRATION RIGHTS AGREEMENT. WE
URGE YOU TO READ THE INDENTURE, THE NOTES AND THE REGISTRATION RIGHTS AGREEMENT
IN THEIR ENTIRETY BECAUSE THEY, AND NOT THIS DESCRIPTION, DEFINE YOUR RIGHTS AS
HOLDERS OF THESE NOTES. YOU MAY REQUEST COPIES OF THESE DOCUMENTS AT OUR ADDRESS
SET FORTH UNDER THE CAPTION "INCORPORATION BY REFERENCE." THE TERMS OF THE NOTES
INCLUDE THOSE STATED IN THE INDENTURE AND THOSE MADE PART OF THE INDENTURE BY
REFERENCE TO THE TRUST INDENTURE ACT OF 1939, AS AMENDED (THE "TRUST INDENTURE
ACT").

GENERAL

    The notes are unsecured, subordinated obligations of Affymetrix. We issued
the notes initially with a principal amount limited to $150,000,000. Interest on
the notes will accrue at the rate of 5% per annum and will be payable
semiannually in arrears on October 1 or April 1 of each year commencing on
April 1, 2000. Interest on the notes will accrue from the date of original
issuance or, if interest has already been paid, from the date it was most
recently paid. We will make each interest payment to the holders of record
("Holders") of these notes on the immediately preceding September 15 or
March 15 as the case may be (whether or not such day is a business day). The
notes will mature on October 1, 2006.

    We will pay the principal of, premium, if any, and interest on the notes at
the office or agency maintained by us in the Borough of Manhattan in New York
City. Holders may register the transfer of their notes at the same location. We
reserve the right to pay interest to Holders of the notes by check mailed to
such Holders at their registered addresses or by wire transfer. Interest on the
notes will be computed on the basis of a 360-day year comprised of twelve 30-day
months.

    The notes will be issued only in fully-registered book-entry form, without
coupons, and, except under the limited circumstances described below, will be
represented by one or more global notes. There will be no service charge for any
registration of transfer or exchange of notes. We may, however, require the
Holders to pay a sum sufficient to cover any tax or other governmental charge
payable in connection with any such transfer or exchange.

BOOK-ENTRY, DELIVERY AND FORM

    We will issue the notes in the form of one or more global notes except as
described under "Certificated Notes" below. The global notes will be deposited
with, or on behalf of, the clearing agency registered under the Exchange Act
that is designated to act as depositary for the notes (the "Depositary") and
registered in the name of the Depositary or its nominee. DTC will be the initial
Depositary. Except as set forth below, the global notes may be transferred, in
whole and not in part, only to the Depositary or another nominee of the
Depositary. You may hold your beneficial interests in the global notes directly
through the Depositary if you have an account with the Depositary or indirectly
through organizations which have accounts with the Depositary.

    The Depositary has advised us that it is:

    - a limited-purpose trust company organized under the laws of the State of
      New York;

    - a member of the Federal Reserve System;

    - a "clearing corporation" within the meaning of the New York Uniform
      Commercial Code; and

    - a "clearing agency" registered pursuant to the provisions of Section 17A
      of the Exchange Act.

                                       20
<PAGE>
    The Depositary was created to hold securities of institutions that have
accounts with the Depositary ("participants") and to facilitate the clearance
and settlement of securities transactions among its participants in such
securities through electronic book-entry changes in accounts of the
participants, thereby eliminating the need for physical movement of securities
certificates. The Depositary's participants include securities brokers and
dealers (which may include the initial purchasers), banks, trust companies,
clearing corporations and certain other organizations. Access to the
Depositary's book-entry system is also available to others such as banks,
brokers, dealers and trust companies that clear through or maintain a custodial
relationship with a participant, whether directly or indirectly.

    Upon the issuance of the global notes, the Depositary will credit, on its
book-entry registration and transfer system, the principal amount of notes
represented by such global notes to the accounts of participants. The initial
purchasers will designate the accounts to be credited. Ownership of beneficial
interests in a global note will be limited to participants or persons that may
hold interests through participants. Ownership of beneficial interests in the
global notes will be shown on, and the transfer of those ownership interests
will be effected only through, records maintained by the Depositary (with
respect to participants' interests) and such participants (with respect to the
owners of beneficial interests in the global notes other than participants). The
laws of some jurisdictions may require that certain purchasers of securities
take physical delivery of such securities in definitive form. Such limits and
laws may impair the ability to transfer or pledge beneficial interests in a
global note.

    So long as the Depositary or its nominee is the registered holder and owner
of a global note, the Depositary or such nominee, as the case may be, will be
considered the sole legal owner and holder of the related notes for all purposes
of such notes and the Indenture. Except as set forth below, as an owner of a
beneficial interest in a global note, you will be subject to the following
limitations:

    - you will not be entitled to have the notes represented by the global notes
      registered in your name;

    - you will not receive or be entitled to receive physical delivery of
      certificated notes; and

    - you will not be considered to be the owners or Holders of any notes under
      the global notes.

    We understand that under existing industry practice, in the event an owner
of a beneficial interest in a global note desires to take any action that the
Depositary, as the holder of the global notes, is entitled to take, the
Depositary would authorize the participants to take such action, and that the
participants would authorize beneficial owners owning through such participants
to take such action or would otherwise act upon the instructions of beneficial
owners owning through them.

    Payment of principal of and premium, if any, and interest on notes
represented by a global note registered in the name of and held by the
Depositary or its nominee will be made to the Depositary or its nominee, as the
case may be, as the registered owner and holder of the global notes.

    We expect that the Depositary or its nominee, upon receipt of any payment of
principal of, premium, if any, or interest on a global note, will credit
participants' accounts with payments in amounts proportionate to their
respective beneficial interests in the principal amount of the global notes as
shown on the records of the Depositary or its nominee. We also expect that
payments by participants to owners of beneficial interests in a global note held
through such participants will be governed by standing instructions and
customary practices and will be the responsibility of such participants. We will
not have any responsibility or liability for any aspect of the records relating
to, or payments made on account of, beneficial ownership interests in the global
notes for any note or for maintaining, supervising or reviewing any records
relating to such beneficial ownership interests or for any other aspect of the
relationship between the Depositary and its participants or the relationship
between such participants and the owners of beneficial interests in the global
notes owning through such participants.

                                       21
<PAGE>
    Unless and until the global notes are exchanged in whole or in part for
certificated notes, the global notes may not be transferred except as a whole by
the Depositary to a nominee of such Depositary or by a nominee of such
Depositary to another nominee of such Depositary.

    Although the Depositary has agreed to the foregoing procedures in order to
facilitate transfers of interests in the global notes among participants of the
Depositary, it is under no obligation to perform or continue to perform such
procedures, and such procedures may be discontinued at any time. Neither we nor
the Trustee will have any responsibility for the performance by the Depositary
or its participants or indirect participants of their respective obligations
under the rules and procedures governing their operations.

YEAR 2000 ISSUES RELATING TO DTC

    DTC management is aware that some computer applications, systems and the
like for processing dates ("Systems") that are dependent upon calendar dates,
including dates before, on or after January 1, 2000, may encounter "year 2000
problems." DTC has informed its participants and other members of the financial
community (the "Industry") that it has developed and is implementing a program
so that its Systems, as the same relate to the timely payment of distributions
(including principal and income payments) to securityholders, book-entry
deliveries and settlement of trades within DTC ("DTC Services"), continue to
function appropriately. This program includes a technical assessment and a
remediation plan, each of which is complete. Additionally, DTC's plan includes a
testing phase, which is expected to be completed within appropriate time frames.

    However, DTC's ability to perform properly its services is also dependent
upon other parties, including but not limited to issuers and their agents, as
well as third-party vendors from whom DTC licenses software and hardware, and
third-party vendors on whom DTC relies for information or the provision of
services, including telecommunication and electrical utility service providers,
among others. DTC has informed the Industry that it is contacting (and will
continue to contact) third-party vendors from whom DTC acquired services to:
(a) impress upon them the importance of such services being year 2000 compliant
and (b) determine the extent of their efforts for year 2000 remediation (and, as
appropriate, testing) of their services. In addition, DTC is in the process of
developing such contingency plans as it deems appropriate.

    According to DTC, the foregoing information with respect to DTC has been
provided to the Industry for informational purposes only and is not intended to
serve as a representation, warranty or contract modification of any kind.

CERTIFICATED NOTES

    The notes represented by the global notes are exchangeable for certificated
notes in definitive form of like tenor in denominations of $1,000 and integral
multiples thereof if:

    - the Depositary notifies us that it is unwilling or unable to continue as
      Depositary for the global notes or if at any time the Depositary ceases to
      be a clearing agency registered under the Exchange Act or announces an
      intention permanently to cease business or in fact does so and, in each
      case, a successor Depositary is not appointed by us;

    - we in our discretion at any time determine not to have all of the notes
      represented by the global notes; or

    - an Event of Default (as defined under the caption "Events of Default") has
      occurred and is continuing.

    Any note that is exchangeable pursuant to the above is exchangeable for
certificated notes issuable in authorized denominations and registered in such
names as the Depositary shall direct. Subject to the

                                       22
<PAGE>
foregoing, the global notes are not exchangeable, except for global notes of the
same aggregate denomination to be registered in the name of the Depositary or
its nominee.

CONVERSION RIGHTS

    A Holder may, at any time prior to the close of business on the business day
immediately preceding the maturity date, convert a note or any portion of a note
into shares of common stock initially at the conversion price of $123.00 per
share unless such note or portion thereof has been previously redeemed. The
right to convert a note called for redemption will terminate on the earlier of
(1) the close of business on the business day immediately preceding the date
fixed for such redemption (the "Redemption Date"), unless we default in making
the payment due on the Redemption Date, and (2) the close of business on the
business day immediately preceding the maturity date of the notes. For
information as to notices of redemption, see "Optional Redemption."

    If we declare or make a distribution in respect of our common stock as
described in clause (4) or (5) below by means of dividend or otherwise, the
Holder of each note, upon conversion of such note after the close of business on
the date fixed for the determination of stockholders entitled to receive such
distribution and prior to the effectiveness of the conversion price adjustment
in respect of such distribution pursuant to clause (4) or (5) below, will be
entitled to receive for each share of common stock into which such note is
converted, the portion to the evidences of indebtedness, shares of capital
stock, cash and other property so distributed applicable to one share of common
stock. In lieu of distributing any portion of such distribution not consisting
of cash or our securities, we may, with respect to all Holders so converting,
pay such Holder cash equal to the fair market value thereof.

    The conversion price will be subject to adjustment upon the occurrence of
certain events, including:

    (1) the issuance of common stock as a dividend or distribution on common
       stock;

    (2) the issuance to all holders of common stock of rights, warrants or
       options entitling them to subscribe for or purchase common stock at less
       than the "current market price" (as defined in the Indenture) per share;

    (3) subdivisions and combinations of common stock;

    (4) distributions to all holders of common stock of evidences of our
       indebtedness, shares of capital stock, securities, cash or property
       (excluding any rights, warrants or options referred to in
       clause (2) above and any dividend or distribution paid exclusively in
       cash and any dividend or distribution referred to in clause (1) above);

    (5) distributions consisting exclusively of cash to all holders of common
       stock in an aggregate amount that, together with (A) other all-cash
       distributions made within the preceding 12 months and (B) any cash and
       the fair market value, as of the expiration of the tender or exchange
       offer referred to below, of consideration payable in respect of any
       tender or exchange offer by us or one of our Subsidiaries (as such term
       is defined in the Indenture) for the common stock concluded within the
       preceding 12 months, exceeds 12.5% of our aggregate market capitalization
       (such aggregate market capitalization being the product of the current
       market price of the common stock multiplied by the number of shares of
       common stock then outstanding) on the date of such distribution; and

    (6) the successful completion of a tender or exchange offer made by us or
       one of our Subsidiaries for the common stock which involves an aggregate
       consideration that, together with (A) any cash and the fair market value
       of other consideration payable in respect of any tender or exchange offer
       by us or one of our Subsidiaries for the common stock concluded within
       the preceding 12 months and (B) the aggregate amount of any all-cash
       distributions to all holders of our common stock

                                       23
<PAGE>
       made within the preceding 12 months, exceeds 12.5% of our aggregate
       market capitalization on the expiration of such tender or exchange offer.

No adjustment of the conversion price will be required to be made until
cumulative adjustments amount to 1% or more of the conversion price as last
adjusted.

    If we distribute rights or warrants (other than those referred to in
clause (2) of the preceding paragraph) pro rata to holders of common stock, so
long as any such rights or warrants have not expired or been redeemed by us, the
Holder of any note surrendered for conversion will be entitled to receive upon
such conversion, in addition to the shares of common stock issuable upon such
conversion (the "Conversion Shares"), a number of rights or warrants to be
determined as follows:

    (1) if such conversion occurs on or prior to the date for the distribution
       to the holders of rights or warrants of separate certificates evidencing
       such rights or warrants (the "Distribution Date"), the same number of
       rights or warrants to which a holder of a number of shares of common
       stock equal to the number of Conversion Shares is entitled at the time of
       such conversion in accordance with the terms and provisions of and
       applicable to the rights or warrants; and

    (2) if such conversion occurs after such Distribution Date, the same number
       of rights or warrants to which a holder of the number of shares of common
       stock into which such Note was convertible immediately prior to such
       Distribution Date would have been entitled on such Distribution Date in
       accordance with the terms and provisions of and applicable to the rights
       or warrants.

The conversion price of the notes will not be subject to adjustment on account
of any declaration, distribution or exercise of such rights or warrants.

    If the common stock is converted into the right to receive other securities,
cash or other property as a result of certain reclassifications, consolidations,
mergers, sales or transfers of assets or other transactions, each note then
outstanding would (without the consent of any Holders of notes) become
convertible only into the kind and amount of securities, cash and other property
receivable upon the transaction by a holder of the number of shares of common
stock which would have been received by a Holder immediately prior to such
transaction if such Holder had converted its notes.

    We will not issue fractional shares of common stock to a Holder who converts
a note. In lieu of issuing fractional shares, we will pay a cash adjustment
based upon the market price.

    Except as described in this paragraph, no Holder of notes will be entitled,
upon conversion thereof, to any actual payment or adjustment on account of
accrued and unpaid interest or on account of dividends on shares of common stock
issued in connection therewith. If any Holder surrenders a note for conversion
between the close of business on any record date for the payment of an
installment of interest and the opening of business on the related interest
payment date (except notes called for redemption on a Redemption Date within
such period between and including such record date and interest payment date),
such Holder must deliver payment to us of an amount equal to the interest
payable on such interest payment date on the principal amount converted together
with the note being surrendered.

    If at any time we make a distribution of property to our stockholders which
would be taxable to such stockholders as a dividend for federal income tax
purposes (e.g., distributions of evidences of our indebtedness or assets, but
generally not stock dividends or rights to subscribe to capital stock) and,
pursuant to the conversion price adjustment provisions of the Indenture, the
conversion price of the notes is reduced, such reduction may be deemed to be the
receipt of taxable income to Holders of the notes.

    We from time to time may decrease the conversion price by any amount for any
period of at least 20 days, in which case we will give at least 15 days' notice
of that decrease, if our board of directors (the "Board") has made a
determination that that decrease would be in our best interests, which
determination will be conclusive. No decrease will be taken into account for
purposes of determining whether the closing

                                       24
<PAGE>
price of the common stock exceeds the conversion price by 105% in connection
with an event which otherwise would be a Change in Control.

    In addition, we may make such reductions in the conversion price as our
Board deems advisable to avoid or diminish any income tax to holders of shares
of common stock resulting from any dividend or distribution of stock (or rights
to acquire stock) or from any event treated as such for income tax purposes or
for any other reasons.

OPTIONAL REDEMPTION

    At any time on or after October 7, 2002, we will be entitled at our option
to redeem all or a portion of these notes upon at least 30 and not more than
60 days' notice by mail to the Holders of the notes, at the following redemption
prices (expressed as percentages of the principal amount on the Redemption
Date), plus accrued and unpaid interest to (but not including) the Redemption
Date (subject to the rights of Holders of record on any relevant record date to
receive interest due on any relevant interest payment date that is on or prior
to such Redemption Date), if redeemed during the periods set forth below:

<TABLE>
<CAPTION>
                                                              REDEMPTION
PERIOD                                                          PRICE
- ------                                                        ----------
<S>                                                           <C>
October 7, 2002 through September 30, 2003..................    102.50%
October 1, 2003 through September 30, 2004..................    101.67%
October 1, 2004 through September 30, 2005..................    100.83%
October 1, 2005 and thereafter..............................    100.00%
</TABLE>

    If we opt to redeem less than all of the notes at any time, the Trustee will
select or cause to be selected the notes to be redeemed by such method as it
deems fair and appropriate. In the event of a partial redemption, the Trustee
may provide for selection for redemption of portions of the principal amount of
any note of a denomination larger than $1,000.

    There is no sinking fund provision in the notes.

CERTAIN RIGHTS TO REQUIRE PURCHASE OF NOTES UPON A CHANGE IN CONTROL

    Upon the occurrence of any of the following events (each, a "Change in
Control"), each Holder of notes will have the right to require that we purchase
such Holder's notes on the date fixed by us that is not less than 30 nor more
than 45 days (the "Purchase Date") after we give notice of the Change in
Control, at a purchase price (the "Purchase Price") in cash equal to 100% of the
principal amount of such notes on the date of purchase plus accrued and unpaid
interest, if any, to the date of purchase:

    (1) any individual, corporation, partnership, joint venture, trust,
       unincorporated organization or government or agency or political
       subdivision thereof (a "Person"), or any Persons acting together in a
       manner which would constitute a "group" (a "Group") for purposes of
       Section 13(d) of the Exchange Act, or any successor provision thereto,
       together with any Affiliates (as defined in the Indenture) thereof,
       (i) become the Beneficial Owners (as defined below), directly or
       indirectly, of our capital stock, entitling such Person or Persons and
       its or their Affiliates to exercise more than 50% of the total voting
       power of all classes of our capital stock entitled to vote generally in
       the election of our directors or (ii) shall succeed in having sufficient
       of its or their nominees (who are not supported by a majority of the then
       current Board) elected to the Board such that such nominees, when added
       to any existing directors remaining on the Board after such election who
       are Affiliates of or acting in concert with such Persons, shall
       constitute a majority of the Board;

    (2) we shall be a party to any transaction pursuant to which the common
       stock is converted into the right to receive other securities (other than
       common stock), cash and/or property (or we, by

                                       25
<PAGE>
       dividend, tender or exchange offer or otherwise, distribute other
       securities, cash and/or property to holders of common stock) and the
       value of all such securities, cash and/or property distributed in such
       transaction and any other transaction effected within the 12 months
       preceding consummation of such transaction (as determined in good faith
       by the Board, whose determination shall be conclusive and described in a
       certified resolution of the Board) is more than 50% of the average of the
       daily Closing Prices for the five consecutive Trading Days ending on the
       Trading Day immediately preceding the date of such transaction (or, if
       earlier, the Trading Day immediately preceding the "ex" date (as defined
       in the Indenture) for such transaction); or

    (3) we shall consolidate with or merger into any other Person or sell,
       convey, transfer or lease our properties and assets substantially as an
       entirety to any Person other than one of our Subsidiaries, or any other
       Person shall consolidate with or merge into us (other than in the case of
       this clause (3), pursuant to any consolidation or merger where Persons
       who are our stockholders immediately prior thereto become the Beneficial
       Owners of shares of capital stock of the surviving company entitling such
       Persons to exercise more than 50% of the total voting power of all
       classes of such surviving company's capital stock entitled to vote
       generally in the election of directors).

On or prior to the Purchase Date, we shall deposit with a paying agent an amount
of money sufficient to pay the aggregate Purchase Price of the notes which is to
be paid on the Purchase Date.

    At our option, instead of paying the Purchase Price in cash, we may pay the
Purchase Price in common stock valued at 95% of the average of the closing sales
prices of the common stock for the five Trading Days immediately preceding and
including the third day prior to the Purchase Date. We may only pay the Purchase
Price in common stock if we satisfy conditions provided in the Indenture.

    We may not purchase any note pursuant to the preceding paragraphs at any
time when the subordination provisions of the Indenture otherwise would prohibit
us from making payments of principal in respect of the notes. If we fail to
purchase the notes when required under the preceding paragraphs, such failure
will constitute an Event of Default (as defined under the caption "Events of
Default") under the Indenture whether or not such purchase is permitted by the
subordination provisions of the Indenture.

    Notwithstanding the foregoing, a Change in Control will not be deemed to
have occurred:

    - if the Closing Price of the common stock for any five Trading Days during
      the ten Trading Days immediately preceding the Change in Control is at
      least equal to 105% of the conversion price in effect immediately
      preceding the Change in Control; or

    - if at least 90% of the consideration (excluding cash payments for
      fractional shares or cash payments for appraisal rights) received or to be
      received by the holders of our common stock in the transaction or
      transactions constituting a Change in Control consists of (x) shares of
      common stock of an entity organized under the laws of a U.S. jurisdiction
      whose shares of common stock are, or upon issuance will be, traded on a
      national securities exchange in the U.S. or through The Nasdaq Stock
      Market, Inc. or (y) shares of common stock of an entity organized under
      the laws of a jurisdiction outside of the U.S., or American Depositary
      Shares representing such shares of common stock, that are, or upon
      issuance will be, traded on a national securities exchange in the U.S. or
      through The Nasdaq Stock Market, Inc., if such entity has a worldwide
      total market capitalization of its equity securities (before giving effect
      to the transaction or transactions constituting a Change in Control) of at
      least US$5 billion.

    On or before the 15th day after we know or reasonably should know a Change
in Control has occurred, we will be required to mail to all Holders of record of
the notes a notice (the "Company Notice") of the occurrence of such Change in
Control, stating:

    - the Purchase Date;

                                       26
<PAGE>
    - the date by which the purchase right must be exercised;

    - the Purchase Price for the notes; and

    - the procedures which a Holder of notes must follow to exercise such
      purchase right.

    To exercise the purchase right, the Holder of a note will be required to
deliver, on or before the 30th day after the date of the Company Notice, an
irrevocable written notice to us (or an agent designated by us for such purpose)
and the Trustee of such Holder's exercise of such right, together with the
certificates evidencing the note or notes with respect to which the right is
being exercised, duly endorsed for transfer. In addition, if the Purchase Date
falls between the relevant record date and the corresponding succeeding interest
payment date, the Holder will be required to deliver with the notes to be
purchased a payment in cash equal to the interest that the Holder is to receive
on such interest payment date.

    The effect of these provisions granting the Holders the right to require us
to purchase the notes upon the occurrence of a Change in Control may make it
more difficult for any person or group to acquire control of Affymetrix or to
effect a business combination with us. Moreover, under the Indenture, we will
not be permitted to pay principal of or interest on, or otherwise acquire the
notes (including any purchase at the election of the Holders of notes upon the
occurrence of a Change in Control) if a payment default on Senior Indebtedness
(as defined under "Subordination" below) has occurred and is continuing, or in
the event of our insolvency, bankruptcy, reorganization, dissolution or other
winding up where Senior Indebtedness is not paid in full. Our ability to pay
cash to Holders of notes following the occurrence of a Change in Control may be
limited by our then existing financial resources. There can be no assurance that
sufficient funds will be available when necessary to make any required
repurchases. See "Risk Factors--We may be unable to raise the funds necessary to
purchase the notes in the event of a Change in Control."

    If a Change in Control occurs and the Holders exercise the rights to require
us to repurchase notes, we intend to comply with applicable tender offer rules
under the Exchange Act, including Rules 13e-4 (other than SEC filing
requirements if not then applicable) and 14e-1, as then in effect, with respect
to any such purchase.

    The term "Beneficial Owner" shall be determined in accordance with
Rules 13d-3 and 13d-5 promulgated by the SEC under the Exchange Act or any
successor provision thereto, except that a Person shall be deemed to have
"beneficial ownership" of all shares that such Person has the right to acquire,
whether such right is exercisable immediately or only after the passage of time.
The term "Trading Day" means each Monday, Tuesday, Wednesday, Thursday and
Friday, other than any day on which securities are not traded on the applicable
securities exchange or in the applicable securities market. The "Closing Price"
on any Trading Day with respect to the per share price of common stock means the
last reported sales price regular way or, in case no such reported sale takes
place on such Trading Day, the average of the reported closing bid and asked
prices regular way, in either case on the New York Stock Exchange or, if the
common stock is not listed or admitted to trading on the New York Stock
Exchange, on the principal national securities exchange on which the common
stock is listed or admitted to trading, or, if not listed or admitted to trading
on any national securities exchange, on The Nasdaq Stock Market, Inc. or if the
common stock is not listed or admitted to trading on any national securities
exchange or The Nasdaq Stock Market, Inc., the average of the closing bid and
asked prices in the over-the-counter market as furnished by any New York Stock
Exchange member firm that we select from time to time for that purpose and is
reasonably acceptable to the Trustee.

                                       27
<PAGE>
REGISTRATION RIGHTS

    We have agreed pursuant to the Registration Rights Agreement, for the
benefit of the Holders of the notes and the common stock issuable upon
conversion of the notes, that we will, at our cost:

    - use our commercially reasonable best efforts to cause this shelf
      registration statement to be declared effective under the Securities Act
      no later than 150 days after the first date of initial issuance of the
      notes; and

    - subject to certain rights to suspend use of the shelf registration
      statement, use our commercially reasonable best efforts to keep the shelf
      registration statement effective until the earliest of (1) the time when
      the notes covered by the shelf registration statement can be sold pursuant
      to Rule 144 under the Securities Act or any successor rule or regulation
      thereto, (2) two years from the effective date and (3) the date on which
      all notes registered under the shelf registration statement are disposed
      of in accordance therewith.

    In the event a shelf registration statement is filed, we will, among other
things:

    - provide to each Holder of notes for whom such shelf registration statement
      was filed, copies of the prospectus which is a part of the shelf
      registration statement;

    - notify each Holder of notes when the shelf registration statement has
      become effective; and

    - take certain other actions as are required to permit unrestricted resales
      of the notes and the common stock issuable upon the conversion of the
      notes by such Holders of the notes to third parties, other than through
      underwritten offerings of an aggregate of less than $50 million aggregate
      principal amount of notes or common stock issuable upon the conversion
      thereof.

    The following requirements and restrictions will generally apply to a Holder
selling such securities pursuant to the shelf registration statement:

    - such Holder will be required to be named as selling security holder in the
      related prospectus;

    - such Holder will be required to deliver a prospectus to purchasers;

    - such Holder will be subject to certain of the civil liability provisions
      under the Securities Act in connection with such sales; and

    - such Holder will be bound by the provisions of the Registration Rights
      Agreement which are applicable to such Holder (including certain
      indemnification obligations).

    If any of the following events occurs (each, a "Registration Default"),
additional interest will accrue on the notes over and above the rate set forth
in the title of the notes at the rate of 0.5% per annum:

    - on or prior to the 150th day after the first date of original issuance of
      the notes, the SEC has not declared the shelf registration statement
      effective; or

    - after the shelf registration statement has been declared effective, such
      shelf registration statement ceases to be effective or usable (subject to
      certain exceptions, including the right to suspend the use of the shelf
      registration statement under certain circumstances for up to 90 days) in
      connection with resales of notes and the common stock issuable upon the
      conversion thereof in accordance with and during the periods specified in
      the Registration Rights Agreement.

Such additional interest will accrue from and including the date on which any
such Registration Default occurs to but excluding the date on which all
Registration Defaults have been cured. We will have no other liabilities for
monetary damages with respect to our registration obligations, except that if we
breach, fail to comply with or violate certain provisions of the Registration
Rights Agreement, the Holders of the notes will be entitled to equitable relief,
including injunction and specific performance. We may not oppose the granting of
such equitable relief.

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CONSOLIDATION, MERGER AND SALE OF ASSETS

    We may, without the consent of the Holders of any of the notes, consolidate
with or merge into any other Person or convey, transfer or lease our properties
substantially as an entirety to, any other Person, if:

    - the successor, transferee or lessee (the "Successor Company") if other
      than us, expressly assumes our obligations under the Indenture and the
      notes by means of a supplemental indenture entered into with the Trustee;

    - after giving effect to the transaction, no Event of Default and no event
      which, with notice or lapse of time, or both, would constitute an Event of
      Default, shall have occurred and be continuing;

    - the Successor Company is (A) organized under the laws of any U.S.
      jurisdiction or (B) is organized under the laws of a jurisdiction outside
      the U.S. and has (i) common stock or American Depositary Shares
      representing such common stock traded on a national securities exchange in
      the U.S. or through The Nasdaq Stock Market, Inc. and (ii) a worldwide
      total market capitalization of its equity securities (before giving effect
      to such consolidation or merger) of at least US$5 billion; and

    - certain other conditions specified in the Indenture are met.

    Under any consolidation by us with, or merger by us into, any other Person
or any conveyance, transfer or lease of our properties and assets substantially
as an entirety as described in the preceding paragraph, the Successor Company
will be our successor and shall succeed to, and be substituted for, and may
exercise every right and power of, Affymetrix under the Indenture, and
thereafter, except in the case of a lease, the predecessor (if still in
existence) will be released from its obligations and covenants under the
Indenture and the notes.

EVENTS OF DEFAULT

    Each of the following is an "Event of Default":

    (1) a default in the payment of any interest upon any of the notes when due
       and payable, continued for 30 days, whether or not such payment is
       prohibited by the subordination provisions of the Indenture;

    (2) a default in the payment of the principal of and premium, if any, on any
       of the notes when due (including on a Redemption Date), whether or not
       such payment is prohibited by the subordination provisions of the
       Indenture;

    (3) a default in our obligation to provide notice of a Change in Control or
       default in the payment of the purchase price in respect of any note on
       the purchase date therefor, whether or not such payment is prohibited by
       the subordination provisions of the Indenture;

    (4) a default by us in the performance, or breach, of any of our other
       covenants in the Indenture which are not remedied by the end of a period
       of 60 days after written notice to us by the Trustee or to us and the
       Trustee by the Holders of at least 25% in principal amount of the
       outstanding notes;

    (5) failure to pay when due the principal of, or acceleration of, any
       indebtedness for money borrowed by us in excess of $10 million, if such
       indebtedness is not discharged, or such acceleration is not waived or
       annulled, by the end of a period of 30 days after written notice to us by
       the Trustee or to us and the Trustee by the Holders of at least 25% of
       principal amount of outstanding notes; or

    (6) certain events of bankruptcy, insolvency or reorganization of
       Affymetrix.

    If an Event of Default (other than of a type referred to in clause (6) of
the preceding paragraph) occurs and is continuing, either the Trustee or the
Holders of at least 25% in principal amount of the outstanding notes may declare
the principal amount of and accrued interest on all notes to be immediately

                                       29
<PAGE>
due and payable. Such declaration may be rescinded if certain conditions are
satisfied. If an Event of Default of the type referred to in clause (6) of the
preceding paragraph occurs, the principal amount of and accrued interest on the
outstanding notes shall automatically become immediately due and payable.

    The Holders of not less than a majority in principal amount of the
outstanding notes may direct the time, method and place of conducting any
proceedings for any remedy available to the Trustee, or exercising any trust or
power conferred on the Trustee; PROVIDED that such direction does not conflict
with any rule of law or with the Indenture. The Trustee may take any other
action deemed proper by the Trustee which is not inconsistent with such
direction.

    Subject to the provisions of the Indenture relating to the duties of the
Trustee, if an Event of Default occurs and is continuing, the Trustee will be
under no obligation to exercise any of the rights or powers under the Indenture
at the request or direction of any of the Holders of the notes unless such
Holders have offered to the Trustee reasonable indemnity or security against any
loss, liability or expense. Except to enforce the right to receive payment of
principal, premium (if any) or interest when due or the right to convert such
Note in accordance with the Indenture, no Holder may institute any proceeding or
pursue any remedy with respect to the Indenture or the notes unless:

    - such Holder has previously given the Trustee notice that an Event of
      Default is continuing;

    - Holders of at least 25% in principal amount of the outstanding notes have
      requested the Trustee to pursue the remedy;

    - such Holders have offered the Trustee security or indemnity satisfactory
      to the Trustee against any loss, liability or expense;

    - the Trustee has not complied with such request within 60 days after the
      receipt thereof and the offer of security or indemnity; and

    - the Holders of a majority in principal amount of the outstanding notes
      have not given the Trustee a direction inconsistent with such request
      within such 60-day period.

    In addition, we are required to deliver to the Trustee, within 120 days
after the end of each fiscal year, a certificate indicating whether the officers
signing such certificate know of any default by us in the performance or
observance of any of the terms of the Indenture. If such officers do know of a
default, the certificate must specify the status and nature of all such
defaults.

MODIFICATION AND WAIVER

    We and the Trustee may enter into one or more supplemental indentures that
add, change or eliminate provisions of the Indenture or modify the rights of the
Holders of the notes with the consent of the Holders of at least a majority in
principal amount of the notes then outstanding. However, without the consent of
each Holder of an outstanding Note affected thereby, no supplemental indenture
may, among other things:

    - change the stated maturity of the principal of or any installment of
      interest on any note;

    - reduce the principal amount of, or the premium or rate of interest on, any
      note;

    - adversely affect the right of any Holder to convert any note as provided
      in the Indenture;

    - change the place of payment where, or the coin of currency in which, the
      principal of any note or any premium or interest thereon is payable;

    - impair the right to institute suit for the enforcement of any such payment
      on or with respect to any note on or after the stated maturity (or, in the
      case of redemption, on or after the Redemption Date);

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<PAGE>
    - modify the subordination provisions of the Indenture in a manner adverse
      to the Holders of the notes;

    - modify the redemption provisions of the Indenture in a manner adverse to
      the Holders of the notes;

    - modify the provisions of the Indenture relating to our requirement to
      offer to purchase notes upon a Change in Control in a manner adverse to
      the Holders of the notes;

    - reduce the percentage in principal amount of the outstanding notes the
      consent of whose Holders is required for any such modification or
      amendment of the Indenture or for any waiver of compliance with certain
      provisions of, or of certain defaults under the Indenture; or

    - modify the foregoing requirements.

    Without the consent of any Holders of notes, we and the Trustee may enter
into one or more supplemental indentures for any of the following purposes:

    (1) to evidence a successor to us and the assumption by such successor of
       our obligations under the Indenture and the notes;

    (2) to add to our covenants for the benefit of the Holders of the notes or
       to surrender any right or power conferred to us;

    (3) to secure our obligations in respect of the notes;

    (4) to make provision with respect to the conversion rights of Holders of
       the notes pursuant to the requirements of the Indenture;

    (5) to make any changes or modifications to the Indenture necessary in
       connection with the registration of the notes under the Securities Act as
       contemplated by the Indenture;

    (6) to cure any ambiguity or inconsistency in the Indenture;

    (7) to comply with any requirement in connection with the qualification of
       the Indenture under the Trust Indenture Act; or

    (8) to make any other provisions with respect to matters or questions
       arising under the Indenture which are not inconsistent with the
       provisions of the Indenture.

However, no supplemental indenture entered into pursuant to clause (5), (6),
(7) or (8) above may adversely affect the interests of the Holders of the notes.

    The Holders of a majority in principal amount of the outstanding notes may,
on behalf of the Holders of all notes, waive compliance by us with certain
restrictive provisions of the Indenture. The Holders of a majority in principal
amount of the outstanding notes may, on behalf of the Holders of all notes,
waive any past default under the Indenture and its consequences, except a
default in the payment of the principal of or any premium or interest on any
note or in respect of a provision which under the Indenture cannot be modified
or amended without the consent of the Holder of each outstanding note affected.

SUBORDINATION

    The payment of the principal of and premium, if any, and interest on the
notes will, to the extent set forth in the Indenture, be subordinated in right
of payment to the prior payment in full of all Senior Indebtedness. When there
is a payment or distribution of assets to creditors upon any liquidation,
dissolution, winding up, reorganization, assignment for the benefit of
creditors, marshaling of assets or any bankruptcy, insolvency or similar
proceedings of Affymetrix, the holders of all Senior Indebtedness will first be
entitled to receive payment in full of all amounts due or to become due thereon,
or provision for such payment in money or money's worth, before the Holders of
the notes will be entitled to receive any payment in respect of the principal of
or premium, if any, or interest on the notes. No payments on account of
principal of, or premium, if any, or interest on the notes or on account of the
purchase or acquisition of

                                       31
<PAGE>
notes may be made if a default in any payment with respect to Senior
Indebtedness has occurred and is continuing or if any judicial proceeding is
pending with respect to any such default.

    By reason of such subordination, in the event of insolvency, our creditors
who are not holders of Senior Indebtedness (including Holders of the notes) may
recover less, ratably, than holders of Senior Indebtedness.

    "Senior Indebtedness" means the principal of and premium, if any, and
interest on all our indebtedness for money borrowed, other than the notes,
whether outstanding on the date of the execution of the Indenture or thereafter
created, incurred, guaranteed or assumed, except such indebtedness that by the
terms of the instrument or instruments by which such indebtedness was created or
incurred expressly provides that it (i) is junior in right of payment to the
notes or (ii) ranks PARI PASSU in right of payment to the notes.

    The term "indebtedness for money borrowed," when used with respect to us,
means:

    - any obligation of, or any obligation guaranteed by, us for the repayment
      of borrowed money, whether or not evidenced by bonds, debentures, notes or
      other written instruments;

    - all our obligations with respect to interest rate hedging arrangements to
      hedge interest rates;

    - any deferred payment obligation of, or any such obligation guaranteed by,
      us for the payment of the purchase price of property or assets evidenced
      by a note or similar instrument; and

    - any obligation of, or any such obligation guaranteed by, us for the
      payment of rent or other amounts under a lease of property or assets which
      obligation is required to be classified and accounted for as a capitalized
      lease on our balance sheet under generally accepted accounting principles.

    At September 30, 1999, Senior Indebtedness was approximately $327,000, all
of which was secured. We expect from time to time to incur additional
indebtedness. The Indenture does not limit or prohibit us from incurring
additional Senior Indebtedness or additional indebtedness.

DEFEASANCE

    We at any time, upon satisfaction of the requirements described below, may
terminate all of our obligations under the notes and the Indenture ("legal
defeasance"), except for certain obligations, including those to maintain a
registrar and paying agents and hold moneys for payment in trust, to register
the transfer or exchange of the notes, to replace mutilated, destroyed, lost or
stolen notes, to provide for conversion of the notes, to comply with the
Registration Rights Agreement, and to purchase the notes in the event of a
Change in Control. In addition, we may terminate our obligations to comply with
certain restrictive covenants ("covenants defeasance") relating to the
maintenance of our properties and payment of taxes and other claims, the
operation of the cross-default and cross-acceleration provisions.

    We may exercise our legal defeasance option notwithstanding our prior
exercise of our covenant defeasance option. If we exercise our defeasance
option, payment of the notes may not be accelerated because of the occurrence of
certain Events of Default.

    To exercise either defeasance option, we must irrevocably deposit in trust
with the Trustee money and/or U.S. Government Obligations (as defined below)
that will provide money in an amount sufficient in the written opinion of a
nationally recognized firm of independent public accountants to pay the
principal of, premium, if any, and each installment of interest on the
outstanding notes. We may only establish such trust if, among other things:

    - no Event of Default (or event that with the passing of time or the giving
      of notice, or both, would constitute an Event of Default) shall have
      occurred or be continuing;

    - we have delivered to the Trustee an opinion of counsel to the effect that
      such deposit shall not cause the trust so created to be subject to the
      Investment Company Act of 1940, as amended;

                                       32
<PAGE>
    - in the case of (A) legal defeasance, we have delivered to the Trustee an
      opinion of counsel to the effect that we have received from, or there has
      been published by, the Internal Revenue Service a ruling or there has been
      a change in law, which in the opinion of our counsel, provides that
      Holders of the notes will not recognize gain or loss for federal income
      tax purposes as a result of such deposit, defeasance and discharge and
      will be subject to federal income tax on the same amount, in the same
      manner and at the same times as would have been the case if such deposit,
      defeasance and discharge had not occurred, or (B) covenant defeasance, we
      have delivered to the Trustee an opinion of counsel to the effect that the
      Holders of the notes will not recognize gain or loss for federal income
      tax purposes as a result of such deposit and defeasance and will be
      subject to federal income tax on the same amount, in the same manner and
      at the same times as would have been the case if such deposit and
      defeasance had not occurred; and

    - we satisfy certain other customary conditions precedent.

    "U.S. Government Obligations" means securities that are (X) direct
obligations of the United States of America for the payment of which its full
faith and credit is pledged or (Y) obligations of a Person controlled or
supervised by and acting as an agency or instrumentality of the United States of
America the payment of which is unconditionally guaranteed as a full faith and
credit obligation by the United States of America, which, in either case, are
not callable or redeemable at the option of the issuer thereof, and shall also
include a depository receipt issued by a bank (as defined in Section 3(a)(2) of
the Securities Act) as a custodian with respect to any such U.S. Government
Obligation or a specific payment of principal of or interest on any such U.S.
Government Obligation held by such custodian for the account of the holder of
such depository receipt; provided that (except as required by law) such
custodian is not authorized to make any deduction from the amount payable to the
holder of such depository receipt from any amount received by the custodian in
respect of the U.S. Government Obligation or the specific payment of principal
of or interest on the U.S. Government Obligation evidenced by such depositary
receipt.

REGARDING THE TRUSTEE

    The Bank of New York is the Trustee under the Indenture.

GOVERNING LAW

    The Indenture and the notes will be governed by and construed in accordance
with the laws of the State of New York without regard to conflict of laws
principles.

                                       33
<PAGE>
            CERTAIN UNITED STATES FEDERAL INCOME TAX CONSIDERATIONS

    The following is a general discussion of the principal United States federal
income tax considerations relevant to the initial purchasers of the notes. This
discussion is based on currently existing provisions of the Internal Revenue
Code of 1986, as amended (the "Code"), existing and proposed Treasury
regulations promulgated thereunder and administrative and judicial
interpretations thereof, all as in effect or proposed on the date hereof and all
of which are subject to change, possibly with retroactive effect.

    This discussion does not deal with all aspects of United States federal
income taxation that may be important to holders of the notes or shares of
common stock received upon conversion thereof, and it does not include any
description of the tax laws of any state, local or foreign government. This
discussion does not address the tax consequences to subsequent beneficial owners
of the notes, and is limited to beneficial owners who hold the notes and the
shares of common stock received upon conversion thereof as capital assets within
the meaning of Section 1221 of the Code. Moreover, this discussion is for
general information only and does not purport to address all of the United
States federal income tax consequences that may be relevant to particular
purchasers (such as certain financial institutions, insurance companies,
tax-exempt entities, dealers in securities or persons who have hedged the risk
of owning a note or a share of common stock) that may be subject to special
rules.

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<PAGE>
    For the purpose of this discussion, a "United States Holder" refers to a
beneficial owner of notes or common stock who or which is:

    - a citizen or resident of the United States for United States federal
      income tax purposes;

    - a corporation or other entity taxable as a corporation created or
      organized in or under the laws of the United States or any political
      subdivision thereof;

    - an estate the income of which is subject to United States Federal income
      taxation regardless of its source;

    - a trust if (A) a United States court is able to exercise primary
      supervision over the administration of the trust and (B) one or more
      United States fiduciaries have authority to control all substantial
      decisions of the trust; or

    - otherwise subject to United States Federal income tax on a net income
      basis in respect of its worldwide taxable income.

    The term "Non-United States Holder" refers to any beneficial owner of a note
or common stock who or which is not a United States Holder.

    PROSPECTIVE PURCHASERS ARE URGED TO CONSULT THEIR OWN TAX ADVISORS AS TO THE
PARTICULAR FEDERAL, STATE, LOCAL AND FOREIGN TAX CONSEQUENCES TO THEM OF THE
ACQUISITION, OWNERSHIP AND DISPOSITION OF THE NOTES, INCLUDING THE CONVERSION OF
THE NOTES INTO SHARES OF COMMON STOCK, AND THE EFFECT THAT THEIR PARTICULAR
CIRCUMSTANCES MAY HAVE ON SUCH TAX CONSEQUENCES.

CERTAIN FEDERAL TAX CONSIDERATIONS APPLICABLE TO UNITED STATES HOLDERS

    INTEREST ON NOTES.  Interest paid on the notes will be taxable to a United
States Holder as ordinary interest income in accordance with such holder's
method of tax accounting. We expect that the notes will not be issued with
original issue discount ("OID") within the meaning of the Code.

    CONSTRUCTIVE DIVIDEND.  Certain corporate transactions, such as
distributions of assets to holders of common stock, may cause a deemed
distribution to the holders of the notes if the conversion price or conversion
ratio of the notes is adjusted to reflect such corporate transaction. Such
deemed distributions will be taxable as a dividend, return of capital, or
capital gain in accordance with the earnings and profits rules discussed under
"Dividends on Shares of Common Stock."

    CONVERSION OF NOTES.  A United States Holder of notes generally will not
recognize gain or loss on the conversion of the notes solely into shares of
common stock (other than cash received in lieu of fractional shares). The United
States Holder's tax basis in the shares of common stock received upon conversion
of the notes will be equal to the holder's aggregate tax basis in the notes
exchanged therefor (less any portion allocable to cash received in lieu of a
fractional share). The holding period of the shares of common stock received by
the holder upon a conversion of the notes generally will include the period
during which the holder held the notes prior to the conversion. In addition,
amounts attributable to accrued interest will be taxed to the holder as ordinary
income. The holder's tax basis in the notes will be increased by such amount.

    Cash received in lieu of a fractional share of common stock should be
treated as a payment in exchange for such fractional share rather than as a
dividend. Gain or loss recognized on the receipt of cash paid in lieu of such
fractional shares generally will equal the difference between the amount of cash
received and the amount of tax basis allocable to the fractional shares
exchanged therefor.

    DIVIDENDS ON SHARES OF COMMON STOCK.  We have never paid any dividends and
do not anticipate paying dividends for the foreseeable future. In the event,
however, that we make distributions on shares of our common stock, the
distributions will constitute dividends for United States federal income tax

                                       35
<PAGE>
purposes to the extent of our current or accumulated earnings and profits as
determined under United States federal income tax principles. Dividends paid to
holders that are United States corporations may qualify for the
dividends-received deduction.

    To the extent, if any, that a United States Holder receives a distribution
on its shares of common stock that would otherwise constitute a dividend for
United States federal income tax purposes but that exceeds our current and
accumulated earnings and profits, the distribution will be treated first as a
non-taxable return of capital reducing the holder's basis in its shares of
common stock. Any such distribution in excess of the holder's basis in its
shares of common stock will be treated as capital gain.

    SALE OR EXCHANGE OF NOTES OR SHARES OF COMMON STOCK.  In general, a United
States Holder of notes will recognize gain or loss upon the sale, redemption,
retirement or other disposition of the notes measured by the difference between:

    - the amount of cash and the fair market value of any property received
      (except to the extent attributable to the payment of accrued interest) and

    - the United States Holder's tax basis in the notes.

    A United States Holder's tax basis in the notes generally will equal the
cost of the notes to the holder. In general, each United States Holder of common
stock into which the notes have been converted will recognize gain or loss upon
the sale, exchange, redemption, or other disposition of the common stock under
rules similar to those applicable to the notes. Special rules may apply to
redemptions of the common stock which may result in the amount paid being
treated as a dividend. Gain or loss on the disposition of the notes or shares of
common stock will be capital gain or loss and will be long-term capital gain or
loss if the holding period of the notes or the common stock that was disposed of
exceeded one year. Net capital gain (i.e., any excess of net long-term capital
gains over net short-term capital losses) realized by individual taxpayers is
taxable at a maximum rate of 20%.

CERTAIN FEDERAL TAX CONSIDERATIONS APPLICABLE TO NON-UNITED STATES HOLDERS

    INTEREST ON NOTES.  Generally, interest paid on the notes to a Non-United
States Holder will not be subject to United States federal income tax if:

    - such interest is not effectively connected with the conduct of a trade or
      business within the United States by such Non-United States Holder;

    - the Non-United States Holder does not actually or constructively own 10%
      or more of the total voting power of all classes of our stock entitled to
      vote and is not a controlled foreign corporation with respect to which we
      are a "related person" within the meaning of the Code (for this purpose,
      the holder of the notes is deemed to own constructively the common stock
      into which the notes could be converted); and

    - the beneficial owner, under penalty of perjury, certifies that the owner
      is not a United States person and provides the owner's name and address.

    If certain requirements are satisfied, the certification described in the
last clause above may be provided by a securities clearing organization, a bank
or other financial institution that holds customers' securities in the ordinary
course of its trade or business. Under recently adopted United States Treasury
regulations, which generally are effective for payments made after December 31,
2000, subject to certain transition rules, the certification described in the
last clause above also may be provided by a qualified intermediary on behalf of
one or more beneficial owners (or other intermediaries), provided that such
intermediary has entered into a withholding agreement with the Internal Revenue
Service and certain other conditions are met. A holder that is not exempt from
tax under these rules will be subject to United States federal income tax
withholding at a rate of 30% unless the interest is effectively connected with
the conduct of a United States trade or business, in which case the interest
will be subject to the United States

                                       36
<PAGE>
federal income tax on net income that applies to United States persons
generally. Corporate Non-United States Holders that receive interest income that
is effectively connected with the conduct of a trade or business within the
United States may also be subject to an additional "branch profits" tax on such
income. Non-United States Holders should consult applicable income tax treaties,
which may provide different rules.

    CONVERSION OF NOTES.  A Non-United States Holder generally will not be
subject to United States federal income tax on the conversion of a note into
shares of common stock. To the extent a Non-United States Holder receives shares
of common stock attributable to accrued interest, such amounts will be taxed as
described above under "Certain Federal Tax Considerations Applicable to
Non-United States Holders--Interest on Notes." To the extent a Non-United States
Holder receives cash in lieu of a fractional share on conversion, such cash may
give rise to gain that would be subject to the rules described below with
respect to the sale or exchange of a note or common stock.

    DIVIDENDS ON SHARES OF COMMON STOCK.  Generally, any distribution on shares
of common stock to a Non-United States Holder will be subject to United States
federal income tax withholding at a rate of 30% unless the dividend is
effectively connected with the conduct of a trade or business within the United
States by the Non-United States Holder, in which case the dividend will be
subject to the United States federal income tax on net income that applies to
United States persons generally. Corporate Non-United States Holders that
receive dividend income that is effectively connected with the conduct of a
trade or business within the United States also may be subject to an additional
"branch profits" tax on such income. Non-United States Holders should consult
any applicable income tax treaties, which may provide for a lower rate of
withholding or other rules different from those described above. A Non-United
States Holder (and in the case of Non-United States Holders that are treated as
partnerships or other fiscally transparent entities, partners, shareholders or
other beneficiaries of such Non-United States Holders) may be required to
satisfy certain certification requirements in order to claim a reduction of or
exemption from withholding under the foregoing rules.

    SALE OR EXCHANGE OF NOTES OR SHARES OF COMMON STOCK.  A Non-United States
Holder generally will not be subject to United States federal income tax on gain
recognized upon the sale or other disposition of the notes or shares of common
stock unless:

    - the gain is (or is treated as) effectively connected with the conduct of a
      trade or business within the United States by the Non-United States
      Holder; or

    - in the case of a Non-United States Holder who is a nonresident alien
      individual and holds the common stock as a capital asset, such holder is
      present in the United States for 183 or more days in the taxable year and
      certain other circumstances are present; or

    - we are a "United States real property holding corporation" for United
      States federal income tax purposes at any time within the shorter of the
      five-year period preceding the disposition or the holder's holding period.
      We do not believe that we currently are a "United States real property
      holding corporation" or that we will become one in the future.

    FEDERAL ESTATE TAXES.  A note beneficially owned by an individual who is a
Non-United States Holder at the time of his or her death generally will not be
subject to U.S. federal estate tax as a result of such individual's death,
provided that:

    - such individual does not actually or constructively own 10% or more of the
      total combined voting power of all classes of our stock entitled to vote
      within the meaning of section 871(h)(3) of the Code; and

    - interest payments with respect to such note would not have been, if
      received at the time of such individual's death, effectively connected
      with the conduct of a U.S. trade or business by such individual.

                                       37
<PAGE>
    Common stock owned or treated as owned by an individual who is a Non-United
States Holder at the time of his or her death will be included in such
individual's estate for United States federal estate tax purposes and thus will
be subject to United States federal estate tax, unless an applicable estate tax
treaty provides otherwise.

INFORMATION REPORTING AND BACKUP WITHHOLDING

    UNITED STATES HOLDERS.  Information reporting and backup withholding may
apply to payments of interest or dividends on, or the proceeds of the sale or
other disposition of, the notes or shares of common stock made by us with
respect to certain non-corporate United States Holders. Such United States
Holders generally will be subject to backup withholding at a rate of 31% unless
the recipient of such payment supplies a taxpayer identification number,
certified under penalties of perjury, as well as certain other information, or
otherwise establishes, in the manner prescribed by law, an exemption from backup
withholding. Any amount withheld under backup withholding is allowable as a
credit against the United States Holder's federal income tax, upon furnishing
the required information to the Internal Revenue Service.

    NON-UNITED STATES HOLDERS.  Generally, information reporting and backup
withholding of United States federal income tax at a rate of 31% may apply to
the payment of principal, interest and premium (if any) to Non-United States
Holders if the payee fails to certify that the holder is a Non-United States
person or if we or our paying agent have actual knowledge that the payee is a
United States person.

    The payment of the proceeds on the disposition of notes or shares of common
stock to or through the United States office of a United States or foreign
broker will be subject to information reporting and backup withholding unless
the owner provides the certification described above or otherwise establishes an
exemption. The proceeds of the disposition by a Non-United States Holder of
notes or shares of common stock to or through a foreign office of a broker will
not be subject to backup withholding. However, if such broker is a United States
person, a controlled foreign corporation for United States tax purposes, or a
foreign person 50% or more of whose gross income from all sources for certain
periods is from activities that are effectively connected with a United States
trade or business, information reporting will apply unless such broker has
documentary evidence of the owner's foreign status and has no actual knowledge
to the contrary or unless the owner otherwise establishes an exemption. Both
backup withholding and information reporting will apply to the proceeds from
such disposition if the broker has actual knowledge that the payee is a United
States Holder.

    Recently adopted United States Treasury regulations, which generally are
effective for payments made after December 31, 2000, subject to certain
transition rules, alter the foregoing rules in certain respects. Among other
things, such regulations provide presumptions under which a Non-United States
Holder is subject to information reporting and backup withholding at the rate of
31% unless we receive certification from the holder of non-U.S. status.
Depending on the circumstances, this certificate will need to be provided:

    - directly by the Non-United States Holder;

    - in the case of a Non-United States Holder that is treated as a partnership
      or other fiscally transparent entity, by the partners, shareholders or
      other beneficiaries of such entity; or

    - certain qualified financial institutions or other qualified entities on
      behalf of the Non-United States Holder.

                                       38
<PAGE>
                            SELLING SECURITY HOLDERS

    The notes were originally issued by us and sold by the initial purchasers in
a transaction exempt from the registration requirements of the Securities Act to
persons reasonably believed by the initial purchasers to be qualified
institutional buyers. Selling holders, including their transferees, pledgees or
donees or their successors, may from time to time offer and sell pursuant to
this prospectus any or all of the notes and common stock into which the notes
are convertible.

    The following table sets forth information with respect to the selling
holders and the principal amounts of notes beneficially owned by each selling
holder that may be offered under this prospectus. The information is based on
information provided by or on behalf of the selling holders. The selling holders
may offer all, some or none of the notes or common stock into which the notes
are convertible. Because the selling holders may offer all or some portion of
the notes or the common stock, no estimate can be given as to the amount of the
notes or the common stock that will be held by the selling holders upon
termination of any sales. In addition, the selling holders identified below may
have sold, transferred or otherwise disposed of all or a portion of their notes
since the date on which they provided the information regarding their notes in
transactions exempt from the registration requirements of the Securities Act.

<TABLE>
<CAPTION>
                                             PRINCIPAL AMOUNT    COMMON STOCK                    COMMON STOCK
                                                 OF NOTES        ISSUABLE UPON                    OWNED AFTER
                                            BENEFICIALLY OWNED   CONVERSION OF      COMMON       COMPLETION OF
NAME                                           AND OFFERED         THE NOTES     STOCK OFFERED   THE OFFERING
- ----                                        ------------------   -------------   -------------   -------------
<S>                                         <C>                  <C>             <C>             <C>
AAM/Zazove Institutional Investment
  Fund....................................      $1,500,000           12,196          12,196             --
AIG National Union Fire Insurance.........         725,000            5,894           5,894             --
Alexandra Global Investment Fund Ltd......       1,000,000            8,130           8,130             --
American Century Heritage Fund............       2,000,000           16,260          16,260
Angelo, Gordon & Co., L.P.................         100,000              813             813             --
Argent Classic Convertible Arbitrage Fund
  (Bermuda) L.P...........................       4,000,000           35,520          35,520             --
Argent Classic Convertible Arbitrage
  Fund L.P................................       1,000,000            8,130           8,130             --
Associated Electric & Gas Insurance
  Services Limited........................         400,000            3,252           3,252             --
BBT Fund, L.P.............................      15,000,000          121,951         121,951             --
BNP Arbitrage SNC.........................       5,250,000           42,683          42,683          8,700
Boulder II Limited........................       2,200,000           17,886          17,886             --
Boulder Capital Inc.......................         400,000            3,252           3,252             --
California Public Employees' Retirement
  System..................................       4,000,000           35,520          35,520             --
Chrysler Corporation Master Retirement
  Trust...................................       2,415,000           19,634          19,634             --
The Class IC Company, Ltd.................       1,000,000            8,130           8,130             --
Delaware PERS.............................       1,525,000           12,398          12,398             --
Employee Benefit Convertible Securities
  Fund....................................         300,000            2,439           2,439             --
Fiduciary Trust Company International.....         500,000            4,065           4,065             --
GLG Global Convertible Fund...............       1,720,000           13,983          13,983
GLG Global Convertible Units Fund.........         280,000            2,276           2,276
GLG Market Neutral Fund...................       3,100,000           25,203          25,203
Global Bermuda Limited Partnership........       1,000,000            8,130           8,130          6,475
Highbridge Capital Corporation............       7,000,000           56,910          56,910             --
ICI American Holdings Trust...............         630,000            5,235           5,235             --
Island Holdings...........................          10,000               81              81             --
Lakeshore International, Ltd..............       2,000,000           16,260          16,260         13,025
Lipper Convertibles, L.P..................       6,500,000           52,845          52,845             --
Lipper Convertibles Series II, L.P........       1,000,000            8,130           8,130             --
Lipper Offshore Convertibles, L.P.........       2,500,000           20,325          20,325             --
</TABLE>

                                       39
<PAGE>

<TABLE>
<CAPTION>
                                             PRINCIPAL AMOUNT    COMMON STOCK                    COMMON STOCK
                                                 OF NOTES        ISSUABLE UPON                    OWNED AFTER
                                            BENEFICIALLY OWNED   CONVERSION OF      COMMON       COMPLETION OF
NAME                                           AND OFFERED         THE NOTES     STOCK OFFERED   THE OFFERING
- ----                                        ------------------   -------------   -------------   -------------
<S>                                         <C>                  <C>             <C>             <C>
Michael Angelo, L.P.......................       1,100,000            8,943           8,943             --
Motion Picture Industry Health
  Plan--Active Member Fund................         280,000            2,276           2,276             --
Motion Picture Industry Health
  Plan--Retiree Member Fund...............         145,000            1,178           1,178             --
Nalco Chemical Retirement.................         325,000            2,439           2,439             --
Nations Capital Income Fund...............       4,000,000           32,520          32,520             --
OCM Convertible Trust.....................       1,300,000           10,569          10,569             --
Onex Industrial Partners Ltd..............         400,000            3,252           3,252             --
Pacific Innovations Trust Capital Income
  Fund....................................         300,000            2,439           2,439             --
Pacific Life Insurance Company............       1,000,000            8,130           8,130
Partner Reinsurance Company Ltd...........         495,000            4,024           4,024             --
Ramius, L.P...............................       1,400,000           11,382          11,382             --
Ramius Securities, LLC....................         350,000            2,845           2,845             --
Raphael, L.P..............................         350,000            2,845           2,845             --
RCG Baldwin, L.P..........................         700,000            5,691           5,691             --
RCG Multi-Strategy Account, L.P...........       1,750,000           14,227          14,227             --
Robertson Stephens........................       5,000,000           40,650          40,650             --
San Diego County Employees Retirement
  Assoc...................................       2,000,000           16,260          16,260             --
SG Cowen Securities Corporation...........       2,000,000           16,260          16,260             --
Starvest Combined Portfolio...............         250,000            2,032           2,032             --
State Employees' Retirement Fund of the
  State of Delaware.......................       1,275,000           10,365          10,365             --
State of Connecticut Combined Investment
  Funds...................................       2,940,000           23,902          23,902             --
State of Oregon Equity....................       7,230,000           58,780          58,780             --
The TCW Group, Inc........................      14,395,000          117,032         117,032             --
Triarc Companies Inc......................         350,000            2,845           2,845             --
Tribeca Investments LLC...................      10,000,000           81,301          81,301             --
Value Line Convertible Fund, Inc..........       1,000,000            8,130           8,130             --
Vanguard Convertible Securities
  Fund, Inc...............................       1,650,000           13,414          13,414             --
Zazove Income Fund, L.P...................       2,000,000           16,260          16,260             --
Zeneca Holdings Trust.....................         625,000            5,081           5,081             --
Other Holders.............................      16,335,000          132,805         132,805             --
</TABLE>

    None of the selling holders nor any of their affiliates, officers, directors
or principal equity holders has held any position or office or has had any
material relationship with us within the past three years, except that Robertson
Stephens was an initial purchaser in connection with the offer and sale of the
notes in September 1999. The selling holders purchased all of the notes from us
in private transactions on or after September 22, 1999. All of the notes were
"restricted securities" under the Securities Act prior to this registration.

    Information concerning the selling holders may change from time to time and
any changed information will be set forth in supplements to this prospectus if
and when necessary. In addition, the conversion rate and therefore, the number
of shares of common stock issuable upon conversion of the notes, is subject to
adjustment under certain circumstances. Accordingly, the aggregate principal
amount of notes and the number of shares of common stock into which the notes
are convertible may increase or decrease.

                                       40
<PAGE>
                              PLAN OF DISTRIBUTION

    The selling holders and their successors, including their transferees,
pledgees or donees or their successors, may sell the notes and the common stock
into which the notes are convertible directly to purchasers or through
underwriters, broker-dealers or agents, who may receive compensation in the form
of discounts, concessions or commissions from the selling holders or the
purchasers. These discounts, concessions or commissions as to any particular
underwriter, broker-dealer or agent may be in excess of those customary in the
types of transactions involved.

    The notes and the common stock into which the notes are convertible may be
sold in one or more transactions at fixed prices, at prevailing market prices at
the time of sale, at prices related to the prevailing market prices, at varying
prices determined at the time of sale, or at negotiated prices. These sales may
be effected in transactions, which may involve crosses or block transactions:

    - on any national securities exchange or U.S. inter-dealer system of a
      registered national securities association on which the notes or the
      common stock may be listed or quoted at the time of sale;

    - in the over-the-counter market;

    - in transactions otherwise than on these exchanges or systems or in the
      over-the-counter market;

    - through the writing of options, whether the options are listed on an
      options exchange or otherwise; or

    - through the settlement of short sales.

    In connection with the sale of the notes and the common stock into which the
notes are convertible or otherwise, the selling holders may enter into hedging
transactions with broker-dealers or other financial institutions, which may in
turn engage in short sales of the notes or the common stock into which the notes
are convertible in the course of hedging the positions they assume. The selling
holders may also sell the notes or the common stock into which the notes are
convertible short and deliver these securities to close out their short
positions, or loan or pledge the notes or the common stock into which the notes
are convertible to broker-dealers that in turn may sell these securities.

    The aggregate proceeds to the selling holders from the sale of the notes or
common stock into which the notes are convertible offered by them will be the
purchase price of the notes or common stock less discounts and commissions, if
any. Each of the selling holders reserves the right to accept and, together with
their agents from time to time, to reject, in whole or in part, any proposed
purchase of notes or common stock to be made directly or through agents. We will
not receive any of the proceeds from this offering.

    Our outstanding common stock is listed for quotation on the Nasdaq National
Market. We do not intend to list the notes for trading on any national
securities exchange or on the Nasdaq National Market and can give no assurance
about the development of any trading market for the notes.

    In order to comply with the securities laws of some states, if applicable,
the notes and common stock into which the notes are convertible may be sold in
these jurisdictions only through registered or licensed brokers or dealers. In
addition, in some states the notes and common stock into which the notes are
convertible may not be sold unless they have been registered or qualified for
sale or an exemption from registration or qualification requirements is
available and is complied with.

    The selling holders and any underwriters, broker-dealers or agents that
participate in the sale of the notes and common stock into which the notes are
convertible may be "underwriters" within the meaning of Section 2(11) of the
Securities Act. Any discounts, commissions, concessions or profit they earn on
any resale of the shares may be underwriting discounts and commissions under the
Securities Act. Selling holders who are "underwriters" within the meaning of
Section 2(11) of the Securities Act will be subject to the prospectus delivery
requirements of the Securities Act. The selling holders have acknowledged that

                                       41
<PAGE>
they understand their obligations to comply with the provisions of the Exchange
Act and the rules thereunder relating to stock manipulation, particularly
Regulation M.

    In addition, any securities covered by this prospectus that qualify for sale
pursuant to Rule 144 or Rule 144A of the Securities Act may be sold under
Rule 144 or Rule 144A rather than pursuant to this prospectus. A selling holder
may not sell any notes or common stock described in this prospectus and may not
transfer, devise or gift these securities by other means not described in this
prospectus.

    To the extent required, the specific notes or common stock to be sold, the
names of the selling holders, the respective purchase prices and public offering
prices, the names of any agent, dealer or underwriter, and any applicable
commissions or discounts with respect to a particular offer will be set forth in
an accompanying prospectus supplement or, if appropriate, a post-effective
amendment to the registration statement of which this prospectus is a part.

    We entered into a registration rights agreement for the benefit of holders
of the notes to register their notes and common stock under applicable federal
and state securities laws under specific circumstances and at specific times.
The registration rights agreement provides for cross-indemnification of the
selling holders and us and their and our respective directors, officers and
controlling persons against specific liabilities in connection with the offer
and sale of the notes and the common stock, including liabilities under the
Securities Act. We will pay substantially all of the expenses incurred by the
selling holders incident to the offering and sale of the notes and the common
stock.

                           VALIDITY OF THE SECURITIES

    The validity of the notes offered hereby and of the shares of common stock
issuable upon conversion thereof will be passed upon for Affymetrix by
Sullivan & Cromwell, Los Angeles, California.

                                    EXPERTS

    Ernst & Young LLP, independent auditors, have audited Affymetrix' financial
statements and schedule included in its Annual Report on Form 10-K for the year
ended December 31, 1998, as set forth in their report, which is incorporated by
reference in this document. Our financial statements and schedule are
incorporated by reference in reliance on Ernst & Young LLP's report, given on
their authority as experts in accounting and auditing.

                                       42
<PAGE>
                                    PART II
                     INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION.

    The following table sets forth all expenses, other than the underwriting
discounts and commissions, payable by the Registrant in connection with the sale
of the common stock being registered. All the amounts shown are estimates except
for the registration fee and the filing fee.

<TABLE>
<S>                                                           <C>
Registration fee............................................  $ 39,600
Legal fees and expenses.....................................   208,367
Accounting fees and expenses................................    22,500
Nasdaq National Market filing fee...........................    17,500
Miscellaneous...............................................   212,033
                                                              --------
  TOTAL.....................................................   500,000
                                                              ========
</TABLE>

ITEM 15. INDEMNIFICATION OF OFFICERS AND DIRECTORS.

    As permitted by Section 102(b)(7) of the Delaware General Corporation Law,
Affymetrix' charter includes a provision that eliminates the personal liability
of a director to Affymetrix or its stockholders for monetary damages arising out
of the director's breach of his or her fiduciary duty. The charter provides,
however, that unless otherwise permitted by applicable law, a director remains
potentially liable for monetary damages for:

    - breach of the director's duty of loyalty to Affymetrix or its
      stockholders;

    - acts or omissions not in good faith or which involve misconduct or a
      knowing violation of law;

    - an improper payment of a dividend or an improper redemption or repurchase
      of Affymetrix' stock (as provided in Section 174 of the Delaware General
      Corporation Law); or

    - any transaction from which a director derives an improper personal
      benefit.

Any repeal or modification of this provision will not affect any right or
protection of a director that exists at the time of such repeal or modification.

    Section 145 of the Delaware General Corporation Law empowers a Delaware
corporation to indemnify any persons who are, or are threatened to be made,
parties to any threatened, pending or completed legal action, suit or
proceeding, whether civil, criminal, administrative or investigative (other than
an action by or in the right of such corporation) by reason of the fact that
such person is or was an officer, director, employee or agent of such
corporation, or is or was serving at the request of such corporation as a
director, officer, employee or agent of another corporation, partnership, joint
venture, trust or other enterprise. The indemnity may include expenses
(including attorneys' fees), judgments, fines and amounts paid in settlement
actually and reasonably incurred by such person in connection with such action,
suit or proceeding, provided that such officer, director, employee or agent
acted in good faith and in a manner he or she reasonably believed to be in or
not opposed to the corporation's best interests, and, for criminal proceedings,
had no reasonable cause to believe his or her conduct was unlawful. A Delaware
corporation may indemnify officers and directors in an action by or in the right
of the corporation under the same conditions, except that no indemnification is
permitted without judicial approval if the officer or director is adjudged to be
liable to the corporation. Where an officer or director is successful on the
merits or otherwise in the defense of any action referred to above, the
corporation must indemnify him or her against the expenses which such officer or
director actually and reasonably incurred.

                                      II-1
<PAGE>
    Article VIII of the bylaws of Affymetrix provides in terms similar to those
of Section 145 of the Delaware General Corporation Law that Affymetrix has the
power and is required to indemnify its directors and officers in accordance with
Delaware Law.

    The right to indemnification includes the right to be paid by Affymetrix the
expenses (including attorneys' fees) incurred in defending any suits brought in
advance of their final disposition; provided, however, that if the Delaware
General Corporation Law requires, an advancement of expenses incurred by an
indemnitee in his or her capacity as a director or officer (and not in any other
capacity in which service was or is rendered by the indemnitee, including,
without limitation, service to an employee benefit plan) will be made only upon
delivery to Affymetrix of an undertaking, by or on behalf of the indemnitee, to
repay all amounts so advanced if it will ultimately be determined by final
judicial decision from which there is no further right to appeal. The rights to
indemnification and to the advancement of expenses covered in Sections 1 and 2
of Article VII of Affymetrix' bylaws are contract rights and these rights
continue as to an indemnitee who has ceased to be a director or officer and will
inure to the benefit of his or her heirs, executors and administrators.

    If a claim covered by Affymetrix' bylaws (Article VIII, Sections 1 and
2) is not paid in full by Affymetrix within 60 days after a written claim has
been received by Affymetrix, except in the case of advancement of expenses
pursuant to the terms of an undertaking, in which case the applicable period is
20 days, an indemnitee will be entitled to be paid also the expense of
prosecuting or defending the suit. The failure of the indemnitee to meet any
applicable standard for indemnification set forth in the Delaware General
Corporation Law:

    - is a defense in any suit brought by the indemnitee to enforce a right to
      indemnification (but not in a suit brought by the indemnitee to enforce a
      right to an advancement of expenses), and

    - entitles Affymetrix to recover an advancement of expenses pursuant to the
      terms of an undertaking upon a final adjudication in any suit brought by
      Affymetrix to recover an advancement of expenses pursuant to the terms of
      an undertaking.

Neither the failure of Affymetrix, including its board of directors, independent
legal counsel, or its stockholders, to have made a determination prior to the
commencement of the suit that indemnification of the indemnitee is proper in the
circumstances because the indemnitee has met the applicable standard of conduct
set forth in the Delaware General Corporation Law, nor an actual determination
by Affymetrix, including its board of directors, independent legal counsel, or
its stockholders, that the indemnitee has not met the applicable standard of
conduct or, in the case of such a suit brought by the indemnitee, is a defense
to the suit. In any suit brought by an indemnitee to enforce a right to
indemnification or to an advancement of expenses, or brought by Affymetrix to
recover an advancement of expenses pursuant to the terms of an undertaking, the
burden of proving that the indemnitee is not entitled to an advancement of
expenses under Article VIII of the bylaws or otherwise will be on Affymetrix.

    The rights to indemnification and to the advancement of expenses conferred
in Affymetrix' bylaws are not exclusive of any other right which any person may
have or acquire under Affymetrix' charter, any statute, agreement, vote of
stockholders or disinterested directors or otherwise.

    Affymetrix may maintain insurance, at its expense, to protect itself and any
director, officer, employee or agent of Affymetrix or another corporation,
partnership, joint venture, trust or other enterprise against any expense,
liability or loss, whether or not Affymetrix would have the power to indemnify
that person against the expense, liability, or loss under the Delaware General
Corporation Law.

    Affymetrix may, to the extent authorized from time to time by the board of
directors, grant rights to indemnification and to the advancement of expenses to
any officer, employee or agent of Affymetrix to the fullest extent of the
provisions allowed by its bylaws with respect to the indemnification and
advancement of expenses of directors and officers of Affymetrix.

                                      II-2
<PAGE>
ITEM 16. EXHIBITS

<TABLE>
<CAPTION>
       EXHIBIT
       NUMBER           DESCRIPTION OF THE DOCUMENT
- ---------------------   ---------------------------
<C>                     <S>
         3.1            Amended and Restated Certificate of Incorporation of
                        Affymetrix, Inc.(1)

         3.2            Bylaws of Affymetrix, Inc.(1)

         4.1            Reference is made to Exhibits 3.1 and 3.2

         4.2            Specimen Stock Certificate(2)

         4.3            Registration Rights Agreement, dated as of September 22,
                        1999, between Affymetrix and certain purchasers listed on
                        the signature page thereto.

         4.4            Indenture, dated as of September 22, 1999, between
                        Affymetrix and The Bank of New York, as Trustee.

         5.1            Opinion of Sullivan & Cromwell.

        23.1            Consent of Ernst & Young LLP, independent auditors.

        23.2            Consent of Sullivan & Cromwell (included in Exhibit 5.1).

        24.1            Power of Attorney (included on the signature page hereto).

        25.1            Form T-1 Statement of Eligibility and Qualification of
                        Trustee.
</TABLE>

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

(1) Incorporated by reference to our Definitive Proxy Statement on Schedule 14A
    filed on April 29, 1998.

(2) Incorporated by reference to Exhibit 4.1 to our Registration Statement
    (No. 333-3648) on Form S-1 filed on June 3, 1996.

ITEM 17. UNDERTAKINGS

    The undersigned registrant hereby undertakes:

    (1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this registration statement:

        (i) To include any prospectus required by Section 10(a)(3) of The
    Securities Act of 1933.

        (ii) To reflect in the prospectus any facts or events arising after the
    effective date of the registration statement (or the most recent
    post-effective amendment thereof) which, individually or in the aggregate,
    represent a fundamental change in the information set forth in the
    registration statement. Notwithstanding the foregoing, any increase or
    decrease in volume of securities offered (if the total dollar value of
    securities offered would not exceed that which was registered) and any
    deviation from the low or high end of the estimated maximum offering range
    may be reflected in the form of prospectus filed with the Commission
    pursuant to Rule 424(b) if, in the aggregate, the changes in volume and
    price represent no more than 20 percent change in the maximum aggregate
    offering price set forth in the "Calculation of Registration Fee" table in
    the effective registration statement.

       (iii) To include any material information with respect to the plan of
    distribution not previously disclosed in the registration statement or any
    material change to such information in the registration statement;

PROVIDED, HOWEVER, that paragraphs (1)(i) and (1)(ii) do not apply if the
information required to be included in a post-effective amendment by those
paragraphs is contained in periodic reports filed with or furnished to the
Commission by the registrant pursuant to Section 13 or 15(d) of the Securities
Exchange Act of 1934 that are incorporated by reference in the registration
statement.

                                      II-3
<PAGE>
    (2) That, for the purpose of determining any liability under the Securities
Act of 1933, each such post-effective amendment that contains a form of
prospectus shall be deemed to be a new registration statement relating to the
securities offered therein, and the offering of such securities at that time
shall be deemed to be the initial BONA FIDE offering thereof.

    (3) To remove from registration by means of a post-effective amendment any
of the securities being registered which remain unsold at the termination of the
offering.

    (4) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to Section 15(d) of the Exchange Act) that is
incorporated by reference in the registration statement shall be deemed to be a
new registration statement relating to the securities offered therein and the
offering of such securities at that time shall be deemed to be the initial BONA
FIDE offering thereof.

    (5) Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
the registrant pursuant to provisions described in Item 15, or otherwise, the
registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.

                                      II-4
<PAGE>
                                   SIGNATURES

    Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-3 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City and County of Santa Clara, State of California on
December 10, 1999.

<TABLE>
<S>                                                    <C>  <C>
                                                       By:               /s/ VERN NORVIEL
                                                            -----------------------------------------
                                                                           Vern Norviel
                                                            Senior Vice President, General Counsel and
                                                                       Corporate Secretary
</TABLE>

                               POWER OF ATTORNEY

    KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears
below constitutes and appoints Stephen Fodor, Edward Hurwitz, and Vern Norviel
and each of them, as his true and lawful attorneys-in-fact and agents, with full
power of substitution and resubstitution, for him and in his name, place and
stead, in any and all capacities, to sign any and all amendments (including
post-effective amendments, exhibits thereto and other documents in connection
therewith) to this registration statement and any subsequent registration
statement filed by the registrant pursuant to Securities and Exchange Commission
Rule 462, which relates to this registration statement and to file the same,
with all exhibits thereto and other documents in connection therewith, with the
Securities and Exchange Commission, granting unto said attorneys-in-fact and
agents and each of them, full power and authority to do and perform each and
every act and thing requisite and necessary to be done in connection therewith,
as fully to all intents and purposes as he might or could do in person, hereby
ratifying and confirming all that said attorneys-in-fact and agents, or any of
them, or their or his substitute or substitutes, may lawfully do or cause to be
done by virtue hereof.

    Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities and on the dates indicated:

<TABLE>
<CAPTION>
                   SIGNATURE                                   TITLE                      DATE
                   ---------                                   -----                      ----
<C>                                               <S>                              <C>
         /s/ STEPHEN P.A. FODOR, PH.D.
     --------------------------------------       Chief Executive Officer and      December 10, 1999
           Stephen P.A. Fodor, Ph.D.                Chairman of the Board

                                                  Vice President and Chief
             /s/ EDWARD M. HURWITZ                  Financial Officer (Principal
     --------------------------------------         Financial and Accounting       December 10, 1999
               Edward M. Hurwitz                    Officer)

           /s/ JOHN D. DIEKMAN, PH.D.
     --------------------------------------       Vice Chairman of the Board       December 10, 1999
             John D. Diekman, Ph.D.

              /s/ PAUL BERG, PH.D.
     --------------------------------------       Director                         December 10, 1999
                Paul Berg, Ph.D.

     --------------------------------------       Director
                 Adrian Hennah
</TABLE>

                                      II-5
<PAGE>

<TABLE>
<CAPTION>
                   SIGNATURE                                   TITLE                      DATE
                   ---------                                   -----                      ----
<C>                                               <S>                              <C>
           /s/ VERNON R. LOUCKS, JR.
     --------------------------------------       Director                         December 10, 1999
             Vernon R. Loucks, Jr.

            /s/ BARRY C. ROSS, PH.D.
     --------------------------------------       Director                         December 10, 1999
              Barry C. Ross, Ph.D.

              /s/ DAVID B. SINGER
     --------------------------------------       Director                         December 10, 1999
                David B. Singer

             /s/ LUBERT STRYER, M.D
     --------------------------------------       Director                         December 10, 1999
              Lubert Stryer, M.D.

               /s/ JOHN A. YOUNG
     --------------------------------------       Director                         December 10, 1999
                 John A. Young
</TABLE>

                                      II-6
<PAGE>
                                 EXHIBITS INDEX

<TABLE>
<CAPTION>
       EXHIBIT
       NUMBER           DESCRIPTION OF THE DOCUMENT
- ---------------------   ---------------------------
<C>                     <S>
         3.1            Amended and Restated Certificate of Incorporation of
                        Affymetrix, Inc.(1)

         3.2            Bylaws of Affymetrix, Inc.(1)

         4.1            Reference is made to Exhibits 3.1 and 3.2.

         4.2            Specimen Stock Certificate(2)

         4.3            Registration Rights Agreement, dated as of September 22,
                        1999, between Affymetrix and certain purchasers listed on
                        the signature page thereto.

         4.4            Indenture, dated as of September 22, 1999, between
                        Affymetrix and The Bank of New York, as Trustee.

         5.1            Opinion of Sullivan & Cromwell.

        23.1            Consent of Ernst & Young LLP, independent auditors.

        23.2            Consent of Sullivan & Cromwell (included in Exhibit 5.1).

        24.1            Power of Attorney (included in the signature page).

        25.1            Form T-1 Statement of Eligibility and Qualification of
                        Trustee.
</TABLE>

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

(1) Incorporated by reference to our Definitive Proxy Statement on Schedule 14A
    filed on April 29, 1998.

(2) Incorporated by reference to Exhibit 4.1 to our Registration Statement
    (No. 333-3648) on Form S-1 filed on June 3, 1996.

<PAGE>
                                                                  EXECUTION COPY
                                  Up to $150,000,000

                                   Affymetrix, Inc.

                      5% Convertible Subordinated Notes due 2006


                            REGISTRATION RIGHTS AGREEMENT


                                                              September 22, 1999

Credit Suisse First Boston Corporation,
as Representative of the several Initial
Purchasers referred to herein,
c/o Credit Suisse First Boston Corporation
Eleven Madison Avenue
New York, New York  10010-3629

Dear Sirs:

          Affymetrix, Inc., a Delaware corporation (the "Company"), proposes to
issue and sell to Credit Suisse First Boston Corporation ("CSFBC") and the other
initial purchasers named in Schedule A to the Purchase Agreement (as defined
below) (collectively, the "Initial Purchasers"), upon the terms set forth in a
purchase agreement dated as of September 16, 1999 (the "Purchase Agreement")
between the Company and the Initial Purchasers, $125,000,000 aggregate principal
amount (plus up to an additional $25,000,000 principal amount) of 5% Convertible
Subordinated Notes Due 2006 (the "Notes") of the Company.  The Notes will be
convertible into shares of Common Stock, par value $0.01 per share, of the
Company (the "Common Stock") at the conversion price set forth in the Offering
Circular dated September 16, 1999.  The Notes will be issued pursuant to an
Indenture, dated as of September 22, 1999 (the "Indenture"), between the Company
and The Bank of New York (the "Trustee").  As an inducement to the Initial
Purchasers to enter into the Purchase Agreement and in satisfaction of a
condition to the Initial Purchasers' obligations thereunder, the Company agrees
with the Initial Purchasers, (i) for the benefit of the Initial Purchasers and
(ii) for the benefit of the holders of the Notes and the Common Stock issuable
upon conversion of the Notes (collectively, the "Securities") from time to time
until such time as such Securities have been sold pursuant to a Shelf
Registration Statement (as defined below) (each of the foregoing a "Holder" and
together the "Holders"), as follows:

          1.  SHELF REGISTRATION.  The Company shall take the following actions:

          (a)  The Company shall, at its cost, prepare and, as promptly as
practicable (but in no event more than 90 days after so required or requested
pursuant to this Section 1) file with the Securities and Exchange Commission
(the "Commission")



<PAGE>

                                                                               2

and thereafter shall use its commercially reasonable best efforts to cause to
be declared effective as soon as practicable a registration statement on Form
S-3 (the "Shelf Registration Statement") covering the offer and sale of the
Transfer Restricted Securities (as defined in Section 5 hereof) by the
Holders thereof from time to time in accordance with the methods of
distribution set forth in the Shelf Registration Statement and Rule 415 under
the Securities Act of 1933, as amended (the "Securities Act") (hereinafter,
the "Shelf Registration"); PROVIDED, HOWEVER, that no Holder (other than the
Initial Purchasers) shall be entitled to have the Securities held by it
covered by such Shelf Registration Statement unless such Holder agrees in
writing to be bound by all the provisions of this Agreement applicable to
such Holder.

          (b)  The Company shall use its commercially reasonable best efforts to
keep the Shelf Registration Statement continuously effective in order to permit
the prospectus included therein (the "Prospectus") to be lawfully delivered by
the Holders of the relevant Securities, for a period of two years (or for such
longer period if extended pursuant to Section 2(h) below) from the date of its
effectiveness or such shorter period that will terminate when all the Securities
covered by the Shelf Registration Statement (i) have been sold pursuant thereto
or (ii) may be sold pursuant to Rule 144(k) under the Securities Act (or any
successor rule therefore), assuming for this purpose that the Holders thereof
are not affiliates of the Company (in any such case, such period being called
the "Shelf Registration Period").  The Company shall be deemed not to have used
its commercially reasonable best efforts to keep the Shelf Registration
Statement effective during the requisite period if it voluntarily takes any
action that would result in Holders of Securities covered thereby not being able
to offer and sell such Securities during that period, unless such action is
(i) required by applicable law or (ii) taken by the Company in good faith and
for valid business reasons upon the occurrence of any event contemplated by
Section 2(b)(v) below, and the Company thereafter complies with the requirements
of Section 2(h).

          (c)  Notwithstanding any other provisions of this Agreement to the
contrary, the Company shall cause the Shelf Registration Statement and the
Prospectus and any amendment or supplement thereto, as of the effective date of
the Shelf Registration Statement, amendment or supplement, (i) to comply in all
material respects with the applicable requirements of the Securities Act and the
rules and regulations of the Commission and (ii) not to contain any untrue
statement of a material fact or omit to state a material fact required to be
stated therein or necessary to make the statements therein, in light of the
circumstances under which they were made, not misleading.

          2.  REGISTRATION PROCEDURES.  In connection with the Shelf
Registration contemplated by Section 1 hereof, the following provisions shall
apply:


<PAGE>

                                                                               3


          (a)  The Company shall (i) furnish to each of the Initial
Purchasers, prior to the filing thereof with the Commission, a copy of the
Shelf Registration Statement and each amendment thereof and each amendment or
supplement, if any, to the prospectus included therein and, in the event that
an Initial Purchaser (with respect to any portion of an unsold allotment from
the original offering) is participating in the Shelf Registration Statement,
use its commercially reasonable best efforts to reflect in each such
document, when so filed with the Commission, such comments as such Initial
Purchaser reasonably may propose; and (ii) include the names of the Holders
who propose to sell Securities pursuant to the Shelf Registration Statement,
as selling security holders.

          (b)  The Company shall give written notice to the Initial Purchasers
and the Holders (which notice pursuant to clauses (ii)-(v) hereof shall be
accompanied by an instruction to suspend the use of the prospectus until the
requisite changes have been made):

          (i) when the Shelf Registration Statement or any amendment thereto has
     been filed with the Commission and when the Shelf Registration Statement or
     any post-effective amendment thereto has become effective;

          (ii) of any request by the Commission for amendments or supplements to
     the Shelf Registration Statement or the prospectus included therein or for
     additional information;

          (iii) of the issuance by the Commission of any stop order suspending
     the effectiveness of the Shelf Registration Statement or the initiation of
     any proceedings for that purpose;

          (iv) of the receipt by the Company or its legal counsel of any
     notification with respect to the suspension of the qualification of the
     Securities for sale in any jurisdiction or the initiation or threatening of
     any proceeding for such purpose; and

          (v) of the happening of any event or circumstance that would require
     the Company to make changes in the Shelf Registration Statement or the
     Prospectus in order that the Shelf Registration Statement or the Prospectus
     does not contain an untrue statement of a material fact nor omit to state a
     material fact required to be stated therein or necessary to make the
     statements therein (in the case of the Prospectus, in light of the
     circumstances under which they were made) not misleading, which written
     notice need not provide any detail

<PAGE>

                                                                               4

      as to the nature of such event.

          (c)  The Company shall make every reasonable effort to obtain the
withdrawal, at the earliest possible time, of any order suspending the
effectiveness of the Shelf Registration Statement.

          (d)  The Company shall furnish to each Holder of Securities included
within the coverage of the Shelf Registration, without charge, at least one copy
of the Shelf Registration Statement and any post-effective amendment thereto,
including financial statements and schedules, and, if the Holder so requests in
writing, all exhibits thereto (including those, if any, incorporated by
reference).

          (e)  The Company shall, during the Shelf Registration Period, deliver
to each Holder of Securities included within the coverage of the Shelf
Registration Statement, without charge, as many copies of the Prospectus
(including each preliminary prospectus) included in the Shelf Registration
Statement and any amendment or supplement thereto as such person may reasonably
request.  The Company consents, subject to the provisions of this Agreement, to
the use of the Prospectus or any amendment or supplement thereto by each of the
selling Holders in connection with the offering and sale of the Securities
covered by the Prospectus, or any amendment or supplement thereto, included in
the Shelf Registration Statement.

          (f)  Prior to any public offering of the Securities pursuant to the
Shelf Registration Statement, the Company shall register or qualify or cooperate
with the Holders of the Securities included therein and their respective counsel
in connection with the registration or qualification of such Securities for
offer and sale under the securities or "blue sky" laws of such states of the
United States as any such Holder reasonably requests in writing and do any and
all other acts or things necessary or advisable to enable the offer and sale in
such jurisdictions of the Securities covered by the Shelf Registration
Statement; PROVIDED, HOWEVER, that the Company shall not be required to (i)
qualify generally to do business in any jurisdiction where it is not then so
qualified or (ii) take any action which would subject it to general service of
process or to taxation in any jurisdiction where it is not then so subject.

          (g)  The Company shall cooperate with the Holders of the Securities to
facilitate the timely preparation and delivery of certificates representing the
Securities to be sold pursuant to the Shelf Registration Statement free of any
restrictive legends and in such denominations and registered in such names as
the Holders may request a reasonable period of time prior to sales of the
Securities pursuant to the Shelf


<PAGE>

                                                                               5

Registration Statement.

          (h)  Upon the occurrence of any event contemplated by paragraphs
(ii) through (v) of Section 2(b) above during the period for which the Company
is required to maintain an effective Shelf Registration Statement, the Company
shall, as required hereby, prepare and file a post-effective amendment to the
Shelf Registration Statement or an amendment or supplement to the Prospectus and
any other required document so that, as thereafter delivered to Holders or
purchasers of Securities, the Prospectus will not contain an untrue statement of
a material fact or omit to state any material fact required to be stated therein
or necessary to make the statements therein, in light of the circumstances under
which they were made, not misleading.  If the Company notifies the Initial
Purchasers and the Holders in accordance with paragraphs (ii) through (v) of
Section 2(b) above to suspend the use of the Prospectus until the requisite
changes to the Prospectus have been made, then the Initial Purchasers and the
Holders shall suspend use of such prospectus and the period of effectiveness of
the Shelf Registration Statement provided for in Section 1(b) above shall be
extended by the number of days from and including the date of giving such notice
to and including the date when the Initial Purchasers and the Holders shall have
received such amended or supplemented prospectus pursuant to this Section 2(h).
Any such amendment, supplement or document will be prepared and filed as
promptly as practicable under the circumstances, as determined in good faith by
the Company, it being understood that the Company may have bona fide reasons to
delay such preparation and filing for a period which may not in any event exceed
60 days.

          (i)  Not later than the effective date of the Shelf Registration
Statement, the Company will provide CUSIP numbers for the Notes and the Common
Stock registered under the Shelf Registration Statement, and provide the Trustee
with printed certificates for such Notes, in a form eligible for deposit with
The Depository Trust Company.

          (j)  The Company will comply with all rules and regulations of the
Commission to the extent and so long as they are applicable to the Shelf
Registration and will make generally available to its security holders (or
otherwise provide in accordance with Section 11(a) of the Securities Act) an
earnings statement satisfying the provisions of Section 11(a) of the Securities
Act, no later than 45 days after the end of a 12-month period (or 90 days, if
such period is a fiscal year) beginning with the first month of the Company's
first fiscal quarter commencing after the effective date of the Shelf
Registration Statement, which statement shall cover such 12-month period.

          (k)  The Company shall cause the Indenture to be qualified under the
Trust Indenture Act of 1939, as amended (the "Trust Indenture Act"), in a timely
manner and containing such changes, if any, as shall be necessary for such
qualification.  In the

<PAGE>

                                                                               6

event that such qualification would require the appointment of a new trustee
under the Indenture, the Company shall appoint a new trustee thereunder
pursuant to the applicable provisions of the Indenture.

          (l)  The Company may require each Holder of Securities to be sold
pursuant to the Shelf Registration Statement to furnish to the Company such
information regarding the Holder and the distribution of the Securities as the
Company may from time to time reasonably require for inclusion in the Shelf
Registration Statement, and the Company may exclude from such registration the
Securities of any Holder that fails to furnish such information within a
reasonable time after receiving such request.

          (m)  The Company shall enter into such customary agreements
(including, if requested, an underwriting agreement in customary form) and take
all other actions, if any, as any Holder shall reasonably request in order to
facilitate the disposition of the Securities pursuant to the Shelf Registration,
PROVIDED, HOWEVER, that the Company shall not be required to facilitate an
underwritten offering pursuant to the Shelf Registration Statement by any
Holders unless the offering relates to at least $50,000,000 principal amount of
the Notes or the equivalent number of shares of Common Stock into which such
Notes are convertible.

          (n)  The Company shall (i) make reasonably available for inspection by
the Holders, any underwriter participating in any distribution pursuant to the
Shelf Registration Statement and any attorney, accountant or other agent
retained by the Holders or any such underwriter, all relevant financial and
other records, pertinent corporate documents and properties of the Company and
(ii) cause the Company's officers, directors, employees, accountants and
auditors to supply all relevant information reasonably requested by the Holders
or any such underwriter, attorney, accountant or agent in connection with the
Shelf Registration Statement, in each case, as shall be reasonably necessary to
enable such persons to conduct a reasonable investigation within the meaning of
Section 11 of the Securities Act; PROVIDED, HOWEVER, that the foregoing
inspection and information gathering (i) shall be coordinated on behalf of the
Initial Purchasers by you and on behalf of the other parties, by one counsel
designated by and on behalf of the other parties as described in Section 3
hereof.

          (o)  The Company, if requested by any Holder of Securities covered by
Shelf Registration Statement, shall cause (i) its counsel (which may include the
Company's general counsel for one or more of the opinions) to deliver an opinion
and updates thereof relating to the Securities in customary form addressed to
such Holders and the managing underwriters, if any, thereof, and dated, in the
case of the initial opinion, the effective date of the Shelf Registration
Statement (it being agreed that the


<PAGE>

                                                                               7

matters to be covered by such opinion shall include, without limitation, (A)
the due incorporation and good standing of the Company; (B) the qualification
of the Company to transact business as a foreign corporation; the due
authorization, execution and delivery of the relevant agreement of the type
referred to in Section 2(m) hereof; (C) the due authorization, execution,
authentication and issuance, and the validity and enforceability, of the
Securities; (D) the absence of material legal or governmental proceedings
involving the Company; (E) the absence of governmental approvals required to
be obtained in connection with the Shelf Registration Statement, the offering
and sale of the Securities, or any agreement of the type referred to in
Section 2(m) hereof; (F) the compliance as to form of the Shelf Registration
Statement and any documents incorporated by reference therein and of the
Indenture with the requirements of the Securities Act and the Trust Indenture
Act, respectively; and, (G) as of the date of the opinion and as of the
effective date of the Shelf Registration Statement or most recent
post-effective amendment thereto, as the case may be, the absence from the
Shelf Registration Statement and the prospectus included therein, as then
amended or supplemented, and from any documents incorporated by reference
therein of an untrue statement of a material fact or the omission to state
therein a material fact required to be stated therein or necessary to make
the statements therein not misleading (in the case of any such documents, in
the light of the circumstances existing at the time that such documents were
filed with the Commission under the Securities Exchange Act of 1934, as
amended (the "Exchange Act"), it being understood that the items contained in
this clause (G) may be in the form of a statement), (ii) its officers to
execute and deliver all customary documents and certificates and updates
thereof requested by any underwriters of the Securities or counsel for the
Holders and (iii) its independent public accountants and the independent
public accountants with respect to any other entity for which financial
information is provided in the Shelf Registration Statement to provide to the
selling Holders of the Securities and any underwriter therefor a comfort
letter in customary form and covering matters of the type customarily covered
in comfort letters in connection with primary underwritten offerings, subject
to receipt of appropriate documentation as contemplated, and only if
permitted, by Statement of Auditing Standards No. 72.

          (p)  The Company shall use its best efforts to take all other steps
necessary to effect the registration of the Securities covered by the Shelf
Registration Statement.

          3.  REGISTRATION EXPENSES.  The Company shall bear all  fees and
expenses incurred in connection with the performance of its obligations under
Sections

<PAGE>

                                                                               8

1 and 2 hereof (including the reasonable fees and expenses, if any, of
counsel for the Initial Purchasers, incurred in connection with the Shelf
Registration), whether or not the Shelf Registration Statement is filed or
becomes effective, and shall bear or reimburse the Holders of the Securities
covered by the Shelf Registration for the reasonable fees and disbursements of
one firm of counsel designated by the Holders of a majority in principal amount
of the Securities covered by the Shelf Registration Statement (provided that
Holders of Common Stock issued upon the conversion of the Notes shall be deemed
to be Holders of the aggregate principal amount of Notes from which such Common
Stock was converted) to act as counsel for the Holders in connection therewith.

          4.  INDEMNIFICATION.  (a)  The Company agrees to indemnify and hold
harmless each Holder and each person, if any, who controls such Holder within
the meaning of the Securities Act or the Exchange Act (each Holder and such
controlling persons are referred to collectively as the "Indemnified Parties")
from and against any losses, claims, damages or liabilities, joint or several,
or any actions in respect thereof (including, but not limited to, any losses,
claims, damages, liabilities or actions relating to purchases and sales of the
Securities) to which each Indemnified Party becomes subject under the Securities
Act, the Exchange Act or otherwise, insofar as such losses, claims, damages,
liabilities or actions arise out of or are based upon any untrue statement or
alleged untrue statement of a material fact contained in the Shelf Registration
Statement or Prospectus, including any document incorporated by reference
therein, or in any amendment or supplement thereto or in any preliminary
prospectus relating to the Shelf Registration, or arise out of, or are based
upon, the omission or alleged omission to state therein a material fact required
to be stated therein or necessary to make the statements therein not misleading,
and shall reimburse, as incurred, the Indemnified Parties for any legal or other
expenses reasonably incurred by them in connection with investigating or
defending any such loss, claim, damage, liability or action in respect thereof;
PROVIDED, HOWEVER, that (i) the Company shall not be liable in any such case to
the extent that such loss, claim, damage or liability arises out of or is based
upon any untrue statement or alleged untrue statement or omission or alleged
omission made in the Shelf Registration Statement or Prospectus or in any
amendment or supplement thereto or in any preliminary prospectus relating to the
Shelf Registration in reliance upon and in conformity with written information
pertaining to such Holder and furnished to the Company by or on behalf of such
Holder specifically for inclusion therein and (ii) with respect to any untrue
statement or omission or alleged untrue statement or omission made in any
preliminary prospectus relating to the Shelf Registration Statement, the
indemnity agreement contained in this subsection (a) shall not inure to the
benefit of any Holder from whom the person asserting any such losses, claims,
damages or liabilities purchased the Securities concerned, to the extent that a
prospectus relating to

<PAGE>

                                                                               9

such Securities was required to be delivered by such Holder under the
Securities Act in connection with such purchase and any such loss, claim,
damage or liability of such Holder results from the fact that there was not
sent or given to such person, at or prior to the written confirmation of the
sale of such Securities to such person, a copy of the final prospectus if the
Company had previously furnished copies thereof to such Holder; PROVIDED
FURTHER, HOWEVER, that this indemnity agreement will be in addition to any
liability which the Company may otherwise have to such Indemnified Party.

          The Company shall also indemnify the underwriters, their officers and
directors and each person who controls such underwriters within the meaning of
the Securities Act or the Exchange Act to the same extent as provided above with
respect to the indemnification of the Holders if requested by such Holders.

          (b)  Each Holder, severally and not jointly, will indemnify and hold
harmless the Company, its officers and directors and each person, if any, who
controls the Company within the meaning of the Securities Act or the Exchange
Act from and against any losses, claims, damages or liabilities or any actions
in respect thereof, to which the Company or any such controlling person may
become subject under the Securities Act, the Exchange Act or otherwise, insofar
as such losses, claims, damages, liabilities or actions arise out of or are
based upon any untrue statement or alleged untrue statement of a material fact
contained in a Shelf Registration Statement or prospectus or in any amendment or
supplement thereto or in any preliminary prospectus relating to a Shelf
Registration, or arise out of or are based upon the omission or alleged omission
to state therein a material fact necessary to make the statements therein not
misleading, but in each case only to the extent that the untrue statement or
omission or alleged untrue statement or omission was made in reliance upon and
in conformity with written information pertaining to such Holder and furnished
to the Company by or on behalf of such Holder specifically for inclusion
therein; and, subject to the limitation set forth immediately preceding this
clause, shall reimburse, as incurred, the Company for any legal or other
expenses reasonably incurred by the Company or any such controlling person in
connection with investigating or defending any loss, claim, damage, liability or
action in respect thereof.  This indemnity agreement will be in addition to any
liability which such Holder may otherwise have to the Company or any of its
controlling persons.

          (c)  Promptly after receipt by an indemnified party under this
Section 4 of notice of the commencement of any action or proceeding (including a
governmental investigation), such indemnified party will, if a claim in respect
thereof is to be made against the indemnifying party under this Section 4,
notify the indemnifying party of the


<PAGE>

                                                                             10

commencement thereof; but the omission so to notify the indemnifying party
will not, in any event, relieve the indemnifying party from any obligations
to any indemnified party other than the indemnification obligation provided
in subsections (a) or (b) above.  In case any such action is brought against
any indemnified party, and it notifies the indemnifying party of the
commencement thereof, the indemnifying party will be entitled to participate
therein and, to the extent that it may wish, jointly with any other
indemnifying party similarly notified, to assume the defense thereof, with
counsel reasonably satisfactory to such indemnified party (who shall not,
except with the consent of the indemnified party, be counsel to the
indemnifying party), and after notice from the indemnifying party to such
indemnified party of its election so to assume the defense thereof the
indemnifying party will not be liable to such indemnified party under this
Section 4 for any legal or other expenses, other than reasonable costs of
investigation, subsequently incurred by such indemnified party in connection
with the defense thereof.  No indemnifying party shall, without the prior
written consent of the indemnified party, effect any settlement of any
pending or threatened action in respect of which any indemnified party is or
could have been a party and indemnity could have been sought hereunder by
such indemnified party unless such settlement includes an unconditional
release of such indemnified party from all liability on any claims that are
the subject matter of such action.

          (d)  If the indemnification provided for in this Section 4 is
unavailable or insufficient to hold harmless an indemnified party under
subsections (a) or (b) above, then each indemnifying party shall contribute to
the amount paid or payable by such indemnified party as a result of the losses,
claims, damages or liabilities (or actions in respect thereof) referred to in
subsections (a) or (b) above (i) in such proportion as is appropriate to reflect
the relative benefits received by the indemnifying party or parties on the one
hand and the indemnified party on the other from the registration of the
Securities, pursuant to the Shelf Registration, or (ii) if the allocation
provided by the foregoing clause (i) is not permitted by applicable law, in such
proportion as is appropriate to reflect not only the relative benefits referred
to in clause (i) above but also the relative fault of the indemnifying party or
parties on the one hand and the indemnified party on the other in connection
with the statements or omissions that resulted in such losses, claims, damages
or liabilities (or actions in respect thereof) as well as any other relevant
equitable considerations.  The relative fault of the parties shall be determined
by reference to, among other things, whether the untrue or alleged untrue
statement of a material fact or the omission or alleged omission to state a
material fact relates to information supplied by the Company on the one hand or
such Holder or such other indemnified party, as the case may be, on the other,
and the parties' relative intent, knowledge, access to information and
opportunity to correct or prevent such statement or omission.  The amount paid
by an indemnified party as a result of the losses, claims, damages or
liabilities referred to in the first sentence of this subsection (d) shall be
deemed to include any legal or other expenses reasonably

<PAGE>

                                                                              11

incurred by such indemnified party in connection with investigating or
defending any action or claim which is the subject of this subsection (d).
Notwithstanding any other provision of this Section 4(d), the Holders shall
not be required to contribute any amount in excess of the amount by which the
net proceeds received by such Holders from the sale of the Securities
pursuant to the Shelf Registration Statement exceeds the amount of damages
which such Holders have 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.  For purposes
of this paragraph (d), each person, if any, who controls such indemnified
party within the meaning of the Securities Act or the Exchange Act shall have
the same rights to contribution as such indemnified party and each person, if
any, who controls the Company within the meaning of the Securities Act or the
Exchange Act shall have the same rights to contribution as the Company.

          (e)  The agreements contained in this Section 4 shall survive the sale
of the Securities pursuant to the Shelf Registration Statement and shall remain
in full force and effect, regardless of any termination or cancellation of this
Agreement or any investigation made by or on behalf of any indemnified party.

          5.  ADDITIONAL INTEREST UNDER CERTAIN CIRCUMSTANCES.  (a)  Additional
interest (the "Additional Interest") with respect to the Notes shall be assessed
as follows if any of the following events occur (each such event in clauses (i)
through (iii) below being herein called a "Registration Default"):

          (i) the Shelf Registration Statement has not been filed with the
     Commission by the 90th day after the first date of original issuance of the
     Notes;

          (ii) the Shelf Registration Statement has not been declared effective
     by the Commission by the 150th day after the first date of original
     issuance of the Notes; or

          (iii) the Shelf Registration Statement is declared effective but
     (A) the Shelf Registration Statement thereafter ceases to be effective; or
     (B) the Shelf Registration Statement or the Prospectus ceases to be usable
     in connection with resales of Transfer Restricted Securities (as defined
     below) during the periods specified herein because either (1) any event
     occurs as a result of which the Prospectus forming part of such Shelf
     Registration Statement would include any untrue statement of a material
     fact or omit to state any material fact necessary to


<PAGE>

                                                                              12

     make the statements therein in the light of the circumstances under which
     they were made not misleading, or (2) it shall be necessary to amend such
     Shelf Registration Statement or supplement the related prospectus, to
     comply with the Securities Act or the Exchange Act or the respective rules
     thereunder.

          Additional Interest shall accrue on the Notes over and above the
interest set forth in the title of the Notes from and including the date on
which any such Registration Default shall occur, to but excluding the date on
which all such Registration Defaults have been cured, at a rate of 0.50% per
annum.

          (b)  A Registration Default referred to in Section 5(a)(iii)(B) shall
be deemed not to have occurred and be continuing in relation to the Shelf
Registration Statement or the Prospectus if (i) such Registration Default has
occurred solely as a result of (x) the filing of a post-effective amendment to
the Shelf Registration Statement to incorporate annual audited financial
information with respect to the Company where such post-effective amendment is
not yet effective and needs to be declared effective to permit Holders to use
the related prospectus or (y) other material events, with respect to the Company
that would need to be described in the Shelf Registration Statement or the
related prospectus and (ii) in the case of clause (y), the Company is proceeding
in good faith to amend or supplement the Shelf Registration Statement and
related prospectus to describe such events as required by paragraph 2(h) hereof;
PROVIDED, HOWEVER, that in any case if such Registration Default occurs for a
continuous period in excess of 90 days, Additional Interest shall be payable in
accordance with the above paragraph from the day such Registration Default
occurs until such Registration Default is cured.

          (c)  Any amounts of Additional Interest due pursuant to Section 5(a)
will be payable in cash on the regular interest payment dates with respect to
the Notes.  The amount of Additional Interest will be determined by multiplying
the applicable Additional Interest rate by the principal amount of the Notes,
further multiplied by a fraction, the numerator of which is the number of days
such Additional Interest rate was applicable during such period (determined on
the basis of a 360-day year comprised of twelve 30-day months), and the
denominator of which is 360.  The indebtedness represented by the Additional
Interest shall be subordinated in right of payment to all existing and future
Senior Indebtedness (as defined in the Indenture) as and to the same extent as
the Notes.

          (d)  "Transfer Restricted Securities" means each Security until (i)
the date on which such Security has been effectively registered under the
Securities Act and disposed of in accordance with the Shelf Registration
Statement or (ii) the date on which such Security is distributed to the public
pursuant to Rule 144 under the Securities Act or is saleable pursuant to Rule
144(k) under the Securities Act.


<PAGE>

                                                                              13

          6.  RULES 144 AND 144A.  The Company shall use its best efforts to
file the reports required to be filed by it under the Securities Act and the
Exchange Act in a timely manner and, if at any time the Company is not required
to file such reports, it will, upon the request of any Holder, make publicly
available other information so long as necessary to permit sales of their
securities pursuant to Rules 144 and 144A.  The Company covenants that it will
take such further action as any Holder may reasonably request, all to the extent
required from time to time to enable such Holder to sell Transfer Restricted
Securities without registration under the Securities Act within the limitations
of the exemptions provided by Rules 144 and 144A (including the requirements of
Rule 144A(d)(4)).  The Company will provide a copy of this Agreement to
prospective purchasers of Securities identified to the Company by the Initial
Purchaser upon request.  Upon the request of any Holder, the Company shall
deliver to such Holder a written statement as to whether it has complied with
such requirements.  Notwithstanding the foregoing, nothing in this Section 6
shall be deemed to require the Company to register any of its securities
pursuant to the Exchange Act.

          7.  UNDERWRITTEN REGISTRATIONS.  If any of the Transfer Restricted
Securities covered by the Shelf Registration are to be sold in an underwritten
offering, the investment banker or investment bankers and manager or managers
that will administer the offering ("Managing Underwriters") will be selected by
the Company.

          No person may participate in any underwritten registration hereunder
unless such person (i) agrees to sell such person's Transfer Restricted
Securities on the basis reasonably provided in any underwriting arrangements
approved by the persons entitled hereunder to approve such arrangements and (ii)
completes and executes all questionnaires, powers of attorney, indemnities,
underwriting agreements and other documents reasonably required under the terms
of such underwriting arrangements.

          8.  MISCELLANEOUS.  (a)  AMENDMENTS AND WAIVERS.  The provisions of
this Agreement may not be amended, modified or supplemented, and waivers or
consents to departures from the provisions hereof may not be given, except by
the Company and the written consent of the Holders of a majority in principal
amount of the Securities (provided that Holders of Common Stock issued upon
conversion of Notes shall not be deemed Holders of Common Stock, but shall be
deemed to be Holders of the aggregate principal amount of Notes from which such
Common Stock was converted) affected by such amendment, modification,
supplement, waiver or consents.


<PAGE>

                                                                              14

          (b)  NOTICES.  All notices and other communications provided for or
permitted hereunder shall be made in writing by hand delivery, first-class mail,
facsimile transmission, or air courier which guarantees overnight delivery:

          (1) if to a Holder, at the most current address given by such Holder
     to the Company;

          (2) if to the Initial Purchasers:

               Credit Suisse First Boston Corporation
               Eleven Madison Avenue
               New York, NY 10010-3629
               Fax No.:  (212) 325-8278
               Attention:  Transactions Advisory Group



<PAGE>

                                                                              15

     with a copy to:

               Cravath, Swaine & Moore
               Worldwide Plaza
               825 Eighth Avenue
               New York, NY 10019
               Fax No.:  (212) 474-3700
               Attention:  Kris Heinzelman, Esq.

          (3) if to the Company, at its address as follows:

               Affymetrix, Inc.
               3380 Central Expressway
               Santa Clara, CA 95051
               Fax No.: (408) 731-5000
               Attention:  Vernon A. Norviel

     with a copy to:

               Sullivan & Cromwell
               1888 Century Park east
               Los Angles, CA  90067-1725
               Fax No.:  (310) 712-8800
               Attention: Stanley F. Farrar, Esq.


          All such notices and communications shall be deemed to have been duly
given:  at the time delivered by hand, if personally delivered; three business
days after being deposited in the mail, postage prepaid, if mailed; when receipt
is acknowledged by recipient's facsimile machine operator, if sent by facsimile
transmission; and on the day delivered, if sent by overnight air courier
guaranteeing next day delivery.

          (c)  NO INCONSISTENT AGREEMENTS.  The Company has not, as of the date
hereof, entered into, nor shall it, on or after the date hereof, without the
prior consent of CSFBC, enter into, any agreement with respect to its securities
that is inconsistent with the rights granted to the Holders herein or otherwise
conflicts with the provisions hereof.

          (d)  SUCCESSORS AND ASSIGNS.  This Agreement shall be binding upon the
Company and its successors and assigns.


<PAGE>

                                                                              16

          (e)  COUNTERPARTS.  This Agreement may be executed in any number of
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be deemed to be an original and all of which taken
together shall constitute one and the same agreement.

          (f)  HEADINGS.  The headings in this Agreement are for convenience of
reference only and shall not limit or otherwise affect the meaning hereof.

          (g)  GOVERNING LAW.  THIS AGREEMENT SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD
TO PRINCIPLES OF CONFLICTS OF LAWS.

          By the execution and delivery of this Agreement, the Company submits
to the nonexclusive jurisdiction of any federal or state court in the State of
New York.

          (h)  SEVERABILITY.  If any one or more of the provisions contained
herein, or the application thereof in any circumstance, is held invalid, illegal
or unenforceable, the validity, legality and enforceability of any such
provision in every other respect and of the remaining provisions contained
herein shall not be affected or impaired thereby.

          (i)  SECURITIES HELD BY THE COMPANY.  Whenever the consent or approval
of Holders of a specified percentage of principal amount of Securities is
required hereunder, Securities held by the Company or its affiliates (other than
subsequent Holders of Securities if such subsequent Holders are deemed to be
affiliates solely by reason of their holdings of such Securities)

<PAGE>



shall not be counted in determining whether such consent or approval was
given by the Holders of such required percentage.

          If the foregoing is in accordance with your understanding of our
agreement, please sign and return to the Company a counterpart hereof, whereupon
this instrument, along with all counterparts, will become a binding agreement
among the Initial Purchasers and the Company in accordance with its terms.


                                   Very truly yours,

                                   AFFYMETRIX, INC.


                                   By:______________________
                                      Name:
                                      Title:

The foregoing Registration
Rights Agreement is hereby confirmed
and accepted as of the date first
above written.


CREDIT SUISSE FIRST BOSTON CORPORATION,
Acting on behalf of themselves and as
The Representative of the several Initial
Purchasers

CREDIT SUISSE FIRST BOSTON CORPORATION,



By:___________________________________
   Name:
   Title:


<PAGE>

                    INDENTURE dated as of September 22, 1999, between
               AFFYMETRIX, INC., a corporation duly organized and existing under
               the laws of the State of Delaware (herein called the "Company"),
               having its principal office at 3380 Central Expressway, Santa
               Clara, California 95051, and THE BANK OF NEW YORK, as Trustee
               (herein called the "Trustee").


          The Company has duly authorized the execution and delivery of this
Indenture to provide for the issuance of its 5% Convertible Subordinated Notes
due 2006 (herein called the "Securities"), to be issued as in this Indenture
provided.

          All things necessary to make the Securities, when executed by the
Company and authenticated and delivered hereunder and duly issued by the
Company, the valid obligations of the Company, and to make this Indenture a
valid agreement of the Company, in accordance with their and its terms, have
been done.


                                W I T N E S S E T H :

          For and in consideration of the premises and the purchase of the
Securities by the Holders thereof, it is mutually agreed, for the equal and
proportionate benefit of all Holders of the Securities or of any series thereof,
as follows:


                                      ARTICLE I

               DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

          SECTION 1.01.  DEFINITIONS.  For all purposes of this Indenture,
except as otherwise expressly provided or unless the context otherwise requires:

          1.  The terms defined in this Article have the meanings assigned to
them in this Article and include the plural as well as the singular.

          2.  All other terms used herein which are defined in the Trust
Indenture Act, either directly or by reference therein, have the meanings
assigned to them therein.

          3.  All accounting terms not otherwise defined herein have the
meanings assigned to them in accordance with generally accepted accounting
principles, and, except as otherwise herein expressly provided, the term
"generally accepted accounting




<PAGE>
                                                                          2


principles" with respect to any computation required or permitted hereunder
shall mean such accounting principles as are generally accepted at the date
of such computation.

          4.  Unless the context otherwise requires, any reference to an
"Article" or a "Section" refers to an Article or Section, as the case may be, of
this Indenture.

          5.  The words "herein", "hereof" and "hereunder" and other words of
similar import refer to this Indenture as a whole and not to any particular
Article, Section or other subdivision.

          Certain terms used in Article XIV have the meanings specified therein.

          "Act", when used with respect to any Holder, has the meaning specified
in Section 1.04.

          "Additional Interest" has the meaning specified in Section 10.11.

          "Affiliate" of any specified Person means any other Person who
directly, or indirectly through one or more intermediaries, controls, is
controlled by, or is under common control with, such specified Person.  For the
purposes of this definition, "control" when used with respect to any specified
Person means the power to direct the management and policies of such Person,
directly or indirectly, whether through the ownership of voting securities, by
contract or otherwise; and the terms "controlling" and "controlled" have
meanings correlative to the foregoing.

          "Agent Member" means any member of, or participant in, the Depositary.

          "Applicable Procedures" means, with respect to any transfer or
transaction involving a Global Security or beneficial interest therein, the
rules and procedures of the Depositary for such Security, in each case to the
extent applicable to such transaction and as in effect from time to time.

          "Authenticating Agent" means any Person authorized by the Trustee
pursuant to Section 6.14 to act on behalf of the Trustee to authenticate
Securities.

          "Beneficial Owner" has the meaning specified in Section 14.07.

          "Board of Directors" means either the board of directors of the
Company or any duly authorized committee of that board.




<PAGE>
                                                                          3


          "Board Resolution" means a copy of a resolution certified by the
Secretary or an Assistant Secretary of the Company to have been duly adopted by
the Board of Directors and to be in full force and effect on the date of such
certification, and delivered to the Trustee.

          "Business Day" means a day on which banking institutions are open for
business and carrying out transactions in Dollars at the relevant place of
payment.

          "Change in Control" has the meaning specified in Section 14.07.

          "Closing Price" on any Trading Day with respect to the per share
price of Common Stock means the last reported sales price regular way or, in
case no such reported sale takes place on such Trading Day, the average of
the reported closing bid and asked prices regular way, in either case on the
New York Stock Exchange or, if the Common Stock is not listed or admitted to
trading on the New York Stock Exchange, on the principal national securities
exchange on which the Common Stock is listed or admitted to trading, or, if
not listed or admitted to trading on any national securities exchange, on
Nasdaq or, if the Common Stock is not listed or admitted to trading on any
national securities exchange or Nasdaq, the average of the closing bid and
asked prices in the over-the-counter market as furnished by any New York
Stock Exchange member firm that is selected from time to time by the Company
for that purpose and is reasonably acceptable to the Trustee.

          "Commencement Date" has the meaning specified in Section 13.04.

          "Commission" means the Securities and Exchange Commission, as from
time to time constituted, created under the Exchange Act, or, if at any time
after the execution of this instrument such Commission is not existing and
performing the duties now assigned to it under the Trust Indenture Act, then
the body performing such duties at such time.

          "Common Stock" includes any stock of any class of the Company which
has no preference in respect of dividends or of amounts payable in the event of
any voluntary or involuntary liquidation, dissolution or winding-up of the
Company and which is not subject to redemption by the Company.  However, subject
to the provisions of Section 13.11, shares issuable on conversion of Securities
shall include only shares of the class designated as Common Stock of the Company
at the date of this instrument or



<PAGE>
                                                                          4


shares of any class or classes resulting from any reclassification or
reclassifications thereof and which have no preference in respect of
dividends or of amounts payable in the event of any voluntary or involuntary
liquidation, dissolution or winding-up of the Company and which are not
subject to redemption by the Company; PROVIDED that if at any time there
shall be more than one such resulting class, the shares of each such class
then so issuable shall be substantially in the proportion which the total
number of shares of such class resulting from all such reclassifications
bears to the total number of shares of all such classes resulting from all
such reclassifications.

          "Company" means the Person named as the "Company" in the first
paragraph of this instrument until a successor Person shall have become such
pursuant to the applicable provisions of this Indenture, and thereafter
"Company" shall mean such successor Person.

          "Company Order" has the meaning specified in the definition of
Company Request in this Section 1.01.

          "Company Request" or "Company Order" means a written request or
order signed in the name of the Company by its Chairman of the Board, its
Vice Chairman of the Board, its President or a Vice President, and by its
Treasurer, an Assistant Treasurer, its Secretary or an Assistant Secretary,
and delivered to the Trustee.

          "Corporate Trust Office" means the principal office of the Trustee
in the city at which at any particular time its corporate trust business
shall be administered.  As of the date hereof, the Corporate Trust Office of
the Trustee is located at 101 Barclay Street, Floor 21 West, New York, New
York 10286.

          "Corporation" means a corporation, association, company,
joint-stock company or business trust.

          "Current Event" has the meaning specified in Section 13.04.

          "Defaulted Interest" has the meaning specified in Section 3.07.

          "Depositary" means, with respect to the Securities issued in whole
or in part in the form of one or more Global Securities, a clearing agency
registered under the Exchange Act that is designated to act as Depositary for
such Securities as contemplated by Section 2.01 (or any successor securities
clearing agency so registered).

          "Distribution Date" has the meaning specified in Section 13.04.


<PAGE>
                                                                          5


          "Dollar" or "U.S.$" means a Dollar or other equivalent unit in such
coin or currency of the United States as at the time shall be legal tender
for the payment of public and private debts.

          "DTC" means The Depository Trust Company, a New York corporation.

          "Event of Default" has the meaning specified in Section 5.01.

          "ex date" has the meaning specified in Section 13.04.

          "Exchange Act" means the Securities Exchange Act of 1934 as it may
be amended from time to time, and any successor act thereto, and the rules
and regulations of the Commission promulgated thereunder.

          "Expiration Date" has the meaning specified in Section 1.04.

          "Expiration Time" has the meaning specified in Section 13.04.

          "Global Security" means a Security that is registered in the
Security Register in the name of a Depositary or a nominee thereof.

          "Group" has the meaning specified in Section 14.07.

          "Holder" means a Person in whose name a Security is registered in
the Security Register.

          "Indenture" means this instrument as originally executed or as it
may from time to time be supplemented or amended by one or more indentures
supplemental hereto entered into pursuant to the applicable provisions
hereof, including, for all purposes of this instrument and any such
supplemental indenture, the provisions of the Trust Indenture Act that are
deemed to be a part of and govern this instrument and any such supplemental
indenture, respectively.

          "Initial Purchasers" means Credit Suisse First Boston Corporation,
BancBoston Robertson Stephens Inc., ING Barings LLC, Lehman Brothers Inc. and
Merrill Lynch, Pierce, Fenner & Smith Incorporated.

          "Interest Payment Date" means the Stated Maturity of an installment
of interest on the Securities.


<PAGE>
                                                                          6


          "Issue Date" means the date of first issuance of the Securities
under this Indenture.

          "junior securities" has the meaning specified in Section 12.14.
          "Maturity", when used with respect to any Security, means the date on
which the principal of such Security or an installment of principal becomes due
and payable as therein or herein provided, whether at the Stated Maturity or by
declaration of acceleration, call for redemption, exercise of the purchase right
or otherwise.

          "Nasdaq" means Nasdaq Stock Market, Inc.

          "Notice of Default" means a written notice of the kind specified in
Section 5.01(4) or 5.01(5).

          "Officers' Certificate" means a certificate signed by any of the
Chairman of the Board, a Vice Chairman of the Board, the Chief Executive
Officer, the President or a Vice President, and by any of the Treasurer, an
Assistant Treasurer, the Secretary or an Assistant Secretary, of the Company,
and delivered to the Trustee. One of the officers signing an Officers'
Certificate given pursuant to Section 10.04 shall be the principal executive,
financial or accounting officer of the Company.

          "Opinion of Counsel" means a written opinion of counsel, who may be
internal counsel for the Company.

          "Other Event" has the meaning specified in Section 13.04.

          "Outstanding", when used with respect to Securities, means, as of
the date of determination, all Securities theretofore authenticated and
delivered under this Indenture, except:

          (i)  Securities theretofore cancelled by the Trustee or delivered to
     the Trustee for cancellation;

     (ii) Securities for whose payment or redemption money in the necessary
     amount has been theretofore deposited with the Trustee or any Paying Agent
     (other than the Company) in trust or set aside and separated in trust by
     the Company (if the


<PAGE>
                                                                          7


     Company shall act as its own Paying Agent) for the Holders of such
     Securities; PROVIDED that, if such Securities are to be redeemed, notice
     of such redemption shall have been duly given pursuant to this Indenture
     or provision therefor satisfactory to the Trustee shall have been made;

     (iii) Securities which have been paid pursuant to Section 3.07 or in
     exchange for or in lieu of which other Securities have been authenticated
     and delivered pursuant to this Indenture, other than any such Securities in
     respect of which there shall have been presented to the Trustee proof
     satisfactory to it that such Securities are held by a bona fide purchaser
     in whose hands such Securities are valid obligations of the Company; and

     (iv) Securities which have been defeased pursuant to Section 15.02;

PROVIDED, HOWEVER, that in determining whether the Holders of the requisite
principal amount of the Outstanding Securities have given, made or taken any
request, demand, authorization, direction, notice, consent, waiver or other
action hereunder as of any date, Securities owned by the Company or any other
obligor upon the Securities or any Affiliate of the Company or of such other
obligor shall be disregarded and deemed not to be Outstanding, except that,
in determining whether the Trustee shall be protected in relying upon any
such request, demand, authorization, direction, notice, consent, waiver or
other action, only Securities which a Responsible Officer of the Trustee
knows to be so owned shall be so disregarded.  Securities so owned which have
been pledged in good faith may be regarded as Outstanding if the pledgee
establishes to the satisfaction of the Trustee the pledgee's right so to act
with respect to such Securities and that the pledgee is not the Company or
any other obligor upon the Securities or any Affiliate of the Company or of
such other obligor.

          "Paying Agent" means any Person authorized by the Company to pay
the principal of (and premium, if any) or interest on any Securities on
behalf of the Company.

          "Person" means any individual, corporation, limited liability
company, partnership, joint venture, trust, unincorporated organization or
government or any agency or political subdivision thereof.

          "Predecessor Security" of any particular Security means every previous
Security evidencing all or a portion of the same debt as that evidenced by such
particular


<PAGE>
                                                                          8


Security; and, for the purposes of this definition, any Security
authenticated and delivered under Section 3.06 in exchange for or in lieu of
a mutilated, destroyed, lost or stolen Security shall be deemed to evidence
the same debt as the mutilated, destroyed, lost or stolen Security.

          "Purchase Date" has the meaning specified in Section 14.01.

          "Purchase Price" has the meaning specified in Section 14.01.

          "Purchased Shares" has the meaning specified in Section 13.04.

          "Qualified Institutional Buyer" means a "qualified institutional
buyer" as defined in Rule 144A.

          "Redemption Date", when used with respect to any Security to be
redeemed, means the date fixed for such redemption by or pursuant to this
Indenture.

          "Redemption Price", when used with respect to any Security to be
redeemed, means the price at which it is to be redeemed as set forth in the
Securities.

          "Reference Date" has the meaning specified in Section 13.04.

          "Registration Default" has the meaning specified in Section 10.11.

          "Registration Rights Agreement" has the meaning specified in
Section 10.11.

          "Regular Record Date" for the interest payable on any Interest
Payment Date means the September 15 or March 15 (whether or not a Business
Day), as the case may be, next preceding such Interest Payment Date.

          "Responsible Officer", when used with respect to the Trustee, means
any officer in the corporate trust department of the Trustee, including any
vice president, assistant vice president, assistant secretary, assistant
treasurer, trust officer or any other officer of the Trustee who customarily
performs functions similar to those performed by the Persons who at the time
shall be such officers, respectively, or to whom any corporate trust matter
is referred because of such person's knowledge of and familiarity with the
particular subject and who shall have direct responsibility for the
administration of this Indenture.


<PAGE>
                                                                          9


          "Restricted Global Security" has the meaning specified in Section
2.01.

          "Restricted Security" means a Security required to bear the
restricted securities legend set forth in Section 2.02.

          "Rule 144A" means Rule 144A under the Securities Act (or any
successor provision), as it may be amended from time to time.

          "Rule 144A Information" has the meaning specified in Section 10.09.

          "Securities" has the meaning stated in the first recital of this
Indenture and more particularly means any Securities authenticated and
delivered under this Indenture and "Security" means one of such Securities.

          "Securities Act" means the Securities Act of 1933 as it may be
amended from time to time, and any successor act thereto, and the rules and
regulations of the Commission promulgated thereunder.

          "Security Register" has the meaning specified in Section 3.05.

          "Security Registrar" has the meaning specified in Section 3.05.

          "Senior Indebtedness" means the principal of and premium, if any, and
interest on all indebtedness of the Company for money borrowed, other than the
Securities, whether outstanding on the date of execution of the Indenture or
thereafter created, incurred, guaranteed or assumed, except such indebtedness
that by the terms of the instrument or instruments by which such indebtedness
was created or incurred expressly provides that it (i) is junior in right of
payment to the Securities or (ii) ranks PARI PASSU in right of payment to the
Securities.  The term "indebtedness for money borrowed" when used with respect
to the Company is defined to mean (i) any obligation of, or any obligation
guaranteed by, the Company for the repayment of borrowed money, whether or not
evidenced by bonds, debentures, notes or other written instruments, (ii) all
obligations of the Company with respect to interest rate hedging agreements to
hedge interest rates, (iii) any deferred payment obligation of, or any such
obligation guaranteed by, the Company for the payment of the purchase price of
property or assets evidenced by a note or similar instrument, and (iv) any
obligation of, or any such obligation guaranteed by, the Company for the payment
of rent or other amounts under a lease of property or


<PAGE>
                                                                         10


assets which obligation is required to be classified and accounted for as a
capitalized lease on the balance sheet of the Company under generally
accepted accounting principles.

          "Shelf Registration Statement" has the meaning specified in Section
10.11.

          "Special Record Date" for the payment of any Defaulted Interest
means a date fixed by the Trustee pursuant to Section 3.07.

          "Stated Maturity", when used with respect to any Security or any
installment of principal thereof or interest thereon, means the date
specified in such Security as the fixed date on which the principal of such
Security or such installment of principal or interest is due and payable.

          "Subsidiary" means a corporation more than 50% of the outstanding
voting stock of which is owned, directly or indirectly, by the Company or by
one or more other Subsidiaries, or by the Company and one or more other
Subsidiaries.  For the purposes of this definition, "voting stock" means
stock which ordinarily has voting power for the election of directors,
whether at all times or only so long as no senior class of stock has such
voting power by reason of any contingency.

          "Surrendered Securities" has the meaning specified in Section 2.07.

          "Trading Day" means each Monday, Tuesday, Wednesday, Thursday and
Friday, other than any day on which securities are not traded on the
applicable securities exchange or in the applicable securities market.

          "Transfer Restricted Securities" has the meaning specified in the
Registration Rights Agreement.

          "Trust Indenture Act" means the Trust Indenture Act of 1939 as in
force at the date as of which this instrument was executed and the rules and
regulations thereunder; PROVIDED, HOWEVER, that in the event the Trust
Indenture Act of 1939 or such rules and regulations are amended after such
date, "Trust Indenture Act" means, to the extent required by any such
amendment, the Trust Indenture Act of 1939 and such rules and regulations as
so amended.

          "Trustee" means the Person named as the "Trustee" in the first
paragraph of this instrument until a successor Trustee shall have become such
pursuant to the applicable provisions of this Indenture, and thereafter
"Trustee" shall mean such


<PAGE>
                                                                         11


successor Trustee.

          "United States" means the United States of America (including the
States thereof and the District of Columbia), its territories, its
possessions and other areas subject to its jurisdiction.

          "U.S. Government Obligation" has the meaning specified in Section
15.04.

          "Vice President", when used with respect to the Company or the
Trustee, means any vice president, whether or not designated by a number or a
word or words added before or after the title "vice president".

          SECTION 1.02.  COMPLIANCE CERTIFICATES AND OPINIONS.  Upon any
application or request by the Company to the Trustee to take any action under
any provision of this Indenture, the Company shall furnish to the Trustee an
Officers' Certificate, if to be given by an officer of the Company, or an
Opinion of Counsel, if to be given by counsel, stating that all conditions
precedent, if any, provided for in this Indenture relating to the proposed
action have been complied with.

          Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Indenture shall include:

          (a)  a statement that each individual signing such certificate or
     opinion has read such covenant or condition and the definitions herein
     relating thereto;

          (b)  a brief statement as to the nature and scope of the examination
     or investigation upon which the statements or opinions contained in such
     certificate or opinion are based;

          (c)  a statement that, in the opinion of each such individual, he has
     made such examination or investigation as is necessary to enable him to
     express an informed opinion as to whether or not such covenant or condition
     has been complied with; and

          (d)  a statement as to whether, in the opinion of each such
     individual, such condition or covenant has been complied with.

<PAGE>

                                                                          12

          SECTION 1.03.  FORM OF DOCUMENTS DELIVERED TO TRUSTEE.  In any case
where several matters are required to be certified by, or covered by an
opinion of, any specified Person, it is not necessary that all such matters
be certified by, or covered by the opinion of, only one such Person, or that
they be so certified or covered by only one document, but one such Person may
certify or give an opinion with respect to some matters and one or more other
such Persons as to other matters, and any such Person may certify or give an
opinion as to such matters in one or several documents.

          Any certificate or opinion of an officer of the Company may be
based, insofar as it relates to legal matters, upon a certificate or opinion
of, or representations by, counsel, unless such officer knows, or in the
exercise of reasonable care should know, that the certificate or opinion or
representations with respect to the matters upon which his certificate or
opinion is based are erroneous. Any such certificate or Opinion of Counsel
may be based, insofar as it relates to factual matters, upon a certificate or
opinion of, or representations by, an officer or officers of the Company
stating that the information with respect to such factual matters is in the
possession of the Company, unless such counsel knows, or in the exercise of
reasonable care should know, that the certificate or opinion or
representations with respect to such matters are erroneous.

          Where any Person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Indenture, they may, but need not, be consolidated and
form one instrument.

          SECTION 1.04.  ACTS OF HOLDERS; RECORD DATES.  Any request, demand,
authorization, direction, notice, consent, waiver or other action provided or
permitted by this Indenture to be given or taken by Holders may be embodied
in and evidenced by one or more instruments of substantially similar tenor
signed by such Holders in person or by an agent duly appointed in writing;
and, except as herein otherwise expressly provided, such action shall become
effective when such instrument or instruments are delivered to the Trustee
and, where it is hereby expressly required, to the Company.  Such instrument
or instruments (and the action embodied therein and evidenced thereby) are
herein sometimes referred to as the "Act" of the Holders signing such
instrument or instruments. Proof of execution of any such instrument or of a
writing appointing any such agent shall be sufficient for any purpose of this
Indenture and (subject to Section 6.01) conclusive in favor of the Trustee
and the Company, if made in the manner provided in this Section 1.04.

          The fact and date of the execution by any Person of any such
instrument or writing may be proved by the affidavit of a witness of such
execution or by a certificate of a notary public or other officer authorized
by law to take acknowledgments of deeds,

<PAGE>

                                                                   13

certifying that the individual signing such instrument or writing
acknowledged to him the execution thereof.  Where such execution is by a
signer acting in a capacity other than his individual capacity, such
certificate or affidavit shall also constitute sufficient proof of his
authority.  The fact and date of the execution of any such instrument or
writing, or the authority of the Person executing the same, may also be
proved in any other manner which the Trustee deems sufficient.

          The ownership of Securities shall be proved by the Security
Register.

          Any request, demand, authorization, direction, notice, consent,
waiver or other Act of the Holder of any Security shall bind every future
Holder of the same Security and the Holder of every Security issued upon the
registration of transfer thereof or in exchange therefor or in lieu thereof
in respect of anything done, omitted or suffered to be done by the Trustee or
the Company in reliance thereon, whether or not notation of such action is
made upon such Security.

          The Company may set any day as a record date for the purpose of
determining the Holders of Outstanding Securities entitled to give or take
any request, demand, authorization, direction, notice, consent, waiver or
other action provided or permitted by this Indenture to be given or taken by
Holders of Securities; PROVIDED that the Company may not set a record date
for, and the provisions of this paragraph shall not apply with respect to,
the giving or making of any notice, declaration, request or direction
referred to in the next paragraph. If any record date is set pursuant to this
paragraph, the Holders of Outstanding Securities on such record date, and no
other Holders, shall be entitled to take the relevant action, whether or not
such Holders remain Holders after such record date; PROVIDED that no such
action shall be effective hereunder unless taken on or prior to the
applicable Expiration Date by Holders of the requisite principal amount of
Outstanding Securities on such record date; and PROVIDED FURTHER, that for
the purpose of determining whether Holders of the requisite principal amount
of such Securities have taken such action, no Security shall be deemed to
have been Outstanding on such record date unless it is also Outstanding on
the date such action is to become effective.  Nothing in this paragraph shall
prevent the Company from setting a new record date for any action for which a
record date has previously been set pursuant to this paragraph (whereupon the
record date previously set shall automatically and with no action by any
Person be cancelled and of no effect), nor shall anything in this paragraph
be construed to render ineffective any action taken by Holders of the
requisite principal amount of Outstanding Securities on the date such action
is taken.  Promptly after any record date is set pursuant to this paragraph,
the Company, at its own expense, shall cause notice of such record date, the
proposed action by Holders and the applicable Expiration Date to be given to
the Trustee in writing and to each Holder of Securities in the manner set
forth in

<PAGE>

                                                                   14

Section 1.06.

          The Trustee may set any day as a record date for the purpose of
determining the Holders of Outstanding Securities entitled to join in the
giving or making of (i) any Notice of Default, (ii) any declaration of
acceleration referred to in Section 5.02, (iii) any request to institute
proceedings referred to in Section 5.07(2), or (iv) any direction referred to
in Section 5.12.  If any record date is set pursuant to this paragraph, the
Holders of Outstanding Securities on such record date, and no other Holders,
shall be entitled to join in such notice, declaration, request or direction,
whether or not such Holders remain Holders after such record date; PROVIDED
that no such action shall be effective hereunder unless taken on or prior to
the applicable Expiration Date by Holders of the requisite principal amount
of Outstanding Securities on such record date; and PROVIDED, FURTHER, that
for the purpose of determining whether Holders of the requisite principal
amount of such Securities have taken such action, no Security shall be deemed
to have been Outstanding on such record date unless it is also Outstanding on
the date such action is to become effective. Nothing in this paragraph shall
be construed to prevent the Trustee from setting a new record date for any
action (whereupon the record date previously set shall automatically and
without any action by any Person be cancelled and of no effect), nor shall
anything in this paragraph be construed to render ineffective any action
taken by Holders of the requisite principal amount of Outstanding Securities
on the date such action is taken.  Promptly after any record date is set
pursuant to this paragraph, the Trustee, at the Company's expense, shall
cause notice of such record date, the proposed action by Holders and the
applicable Expiration Date to be given to the Company in writing and to each
Holder of Securities in the manner set forth in Section 1.06.

          With respect to any record date set pursuant to this Section, the
party hereto that sets such record date may designate any day as the
"Expiration Date" and from time to time may change the Expiration Date to any
earlier or later day; PROVIDED that no such change shall be effective unless
notice of the proposed new Expiration Date is given to the other party hereto
in writing, and to each Holder of Securities in the manner set forth in
Section 1.06, on or before the existing Expiration Date. Notwithstanding the
foregoing, no Expiration Date shall be later than the 180th day after the
applicable record date and, if an Expiration Date is not designated with
respect to any record date set pursuant to this Section, the party hereto
that set such record date shall be deemed to have designated the 180th day
after such record date as the Expiration Date with respect thereto.

<PAGE>

                                                                   15

          Without limiting the foregoing, a Holder entitled hereunder to take
any action hereunder with regard to any particular Security may do so with
regard to all or any part of the principal amount of such Security or by one
or more duly appointed agents, each of which may do so pursuant to such
appointment with regard to all or any part of such principal amount.

          SECTION 1.05.  NOTICES, ETC. TO TRUSTEE AND COMPANY.  Any request,
demand, authorization, direction, notice, consent, waiver or Act of Holders
or other document provided or permitted by this Indenture to be made upon,
given or furnished to, or filed with,

          (1) the Trustee by any Holder or by the Company shall be
sufficiently given if made, given, furnished or filed in writing to or with
the Trustee at its Corporate Trust Office, Attention: Corporate Trust
Administration, or at any other address previously furnished in writing to
the Company by the Trustee, or

          (2) the Company by the Trustee or by any Holder shall be sufficiently
given (unless otherwise herein expressly provided) if in writing and mailed,
first-class postage prepaid, to the Company, addressed to it at the address of
its principal office specified in the first paragraph of this instrument or at
any other address previously furnished in writing to the Trustee by the Company.

          SECTION 1.06. NOTICE TO HOLDERS; WAIVER.  Where this Indenture
provides for notice to Holders of any event, such notice shall be sufficiently
given (unless otherwise herein expressly provided) if in writing and mailed,
first-class postage prepaid, to each Holder affected by such event, at his
address as it appears in the Security Register, not later than the latest date
(if any), and not earlier than the earliest date (if any), prescribed for the
giving of such notice.  In any case where notice to Holders is given by mail,
neither the failure to mail such notice, nor any defect in any notice so mailed,
to any particular Holder shall affect the sufficiency of such notice with
respect to other Holders.  Where this Indenture provides for notice in any
manner, such notice may be waived in writing by the Person entitled to receive
such notice, either before or after the event, and such waiver shall be the
equivalent of such notice.  Waivers of notice by Holders shall be filed with the
Trustee, but such filing shall not be a condition precedent to the validity of
any action taken in reliance upon such waiver.

          In case by reason of the suspension of regular mail service or by
reason of any other cause it shall be impracticable to give such notice by mail,
then such notification as shall be made with the approval of the Trustee shall
constitute a sufficient notification for every purpose hereunder.

<PAGE>

                                                                   16

          SECTION 1.07. CONFLICT WITH TRUST INDENTURE ACT.  If any provision
hereof limits, qualifies or conflicts with a provision of the Trust Indenture
Act which is required under such Act to be a part of and govern this
Indenture, the latter provision shall control.  If any provision of this
Indenture modifies or excludes any provision of the Trust Indenture Act which
may be so modified or excluded, the latter provision shall be deemed to apply
to this Indenture as so modified or to be excluded, as the case may be. To
the extent a Security conflicts with a provision in the Indenture, the
Indenture governs.

          SECTION 1.08.  EFFECT OF HEADINGS AND TABLE OF CONTENTS.  The
Article and Section headings herein and the Table of Contents are for
convenience only and shall not affect the construction hereof.

          SECTION 1.09.  SUCCESSORS AND ASSIGNS.  All covenants and
agreements in this Indenture by the Company shall bind its successors and
assigns, whether so expressed or not.

          SECTION 1.10.  SEVERABILITY CLAUSE.  In case any provision in this
Indenture or in the Securities shall be invalid, illegal or unenforceable,
the validity, legality and enforceability of the remaining provisions shall
not in any way be affected or impaired thereby.

          SECTION 1.11.  BENEFITS OF INDENTURE.  Nothing in this Indenture or
in the Securities, express or implied, shall give to any Person, other than
the parties hereto and their successors hereunder, the holders of Senior
Indebtedness and the Holders of Securities, any benefit or any legal or
equitable right, remedy or claim under this Indenture.

          SECTION 1.12. GOVERNING LAW.  THIS INDENTURE AND THE SECURITIES
SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE OF
NEW YORK WITHOUT REGARD TO CONFLICT OF LAWS PRINCIPLES.

          SECTION 1. 13.  LEGAL HOLIDAYS.  In any case where any Interest
Payment Date, Redemption Date, Purchase Date or Stated Maturity of any
Security or the last date on which a Holder has the right to convert his
Securities shall not be a Business Day then (notwithstanding any other
provision of this Indenture or of the Securities) payment of interest or
principal (and premium, if any) or conversion of the Securities need not be
made on such date, but may be made on the next succeeding Business Day with
the same

<PAGE>

                                                                   17

force and effect as if made on the Interest Payment Date, Redemption Date,
Purchase Date or at the Stated Maturity, or on such last day for conversion;
PROVIDED that no interest shall accrue for the period from and after such
Interest Payment Date, Redemption Date, Purchase Date or Stated Maturity, as
the case may be.

                                      ARTICLE II

                                    SECURITY FORMS

          SECTION 2.01.  FORMS GENERALLY.  The Securities, the conversion
notice and the Trustee's certificates of authentication shall be in
substantially the forms set forth in this Article, with such appropriate
insertions, omissions, substitutions and other variations as are required or
permitted by this Indenture, and may have such letters, numbers or other
marks of identification and such legends or endorsements placed thereon as
may be required to comply with the rules of any securities exchange or
Depositary therefor or as may, consistently herewith, be determined by the
officers executing such Securities, as evidenced by their execution of the
Securities.

          The definitive Securities shall be printed, lithographed or
engraved on steel engraved borders or may be produced in any other manner,
all as determined by the officers executing such Securities, as evidenced by
their execution of such Securities.

          In certain cases described elsewhere herein, the legends set forth
in the first four paragraphs of Section 2.02 may be omitted from Securities
issued hereunder.

          Upon their original issuance, Securities offered and sold as
provided in the Purchase Agreement, shall be issued in the form of a single
Global Security in definitive, fully registered form without interest
coupons, substantially in the form of Security set forth in Sections 2.02 and
2.03, with such applicable legends as are provided for in Section 2.02,
except as otherwise permitted herein.  Such Global Security shall be
registered in the name of DTC, as Depositary, or its nominee or successor,
duly executed by the Company and authenticated by the Trustee as hereinafter
provided, and deposited with the Trustee, as custodian for DTC, for credit by
DTC to the respective accounts of beneficial owners of the Securities
represented thereby (or such other accounts as they may direct).  Such Global
Security, together with its Successor Securities which are Global Securities,
are collectively herein called the "Restricted Global Security".

          Except as provided in this Section 2.01 or Section 3.05, owners of
beneficial interests in Global Securities will not be entitled to receive
physical delivery of

<PAGE>

                                                                   18

certificated Securities.  Upon transfer of definitive Securities to a
Qualified Institutional Buyer, such definitive Securities will, unless the
Restricted Global Security has previously been exchanged, be exchanged for an
interest in the Restricted Global Security pursuant to the provisions of
Section 3.05.

          Neither the Company nor the Trustee shall have any responsibility
for any defect in the CUSIP number that appears on any Security, check,
advice of payment or redemption or purchase notice, and any such document may
contain a statement to the effect that CUSIP numbers have been assigned by an
independent service for convenience of reference and that neither the Company
nor the Trustee shall be liable for any inaccuracy in such numbers.

          SECTION 2.02.  FORM OF FACE OF SECURITY.

          [INCLUDE IF SECURITY IS A RESTRICTED SECURITY OR A DEFINITIVE SECURITY
OTHER THAN A RESTRICTED GLOBAL SECURITY:

          THIS SECURITY (OR ITS PREDECESSOR) WAS ORIGINALLY ISSUED IN A
TRANSACTION EXEMPT FROM REGISTRATION UNDER THE UNITED STATES SECURITIES ACT
OF 1933 (THE "SECURITIES ACT"), AND THIS SECURITY AND THE COMMON STOCK
ISSUABLE UPON THE CONVERSION THEREOF MAY NOT BE OFFERED, SOLD OR OTHERWISE
TRANSFERRED IN THE ABSENCE OF SUCH REGISTRATION OR IN A TRANSACTION EXEMPT
FROM, OR NOT SUBJECT TO, THE SECURITIES ACT. EACH PURCHASER OF THIS SECURITY
IS HEREBY NOTIFIED THAT THE SELLER OF THIS SECURITY, AND THE COMMON STOCK
ISSUABLE UPON THE CONVERSION THEREOF, MAY BE RELYING ON THE EXEMPTION FROM
THE PROVISIONS OF SECTION 5 OF THE SECURITIES ACT PROVIDED BY RULE 144A
THEREUNDER.

          THE HOLDER OF THIS SECURITY AGREES FOR THE BENEFIT OF THE COMPANY
THAT (A) THIS SECURITY AND THE COMMON STOCK ISSUABLE UPON THE CONVERSION
THEREOF MAY BE OFFERED, RESOLD, PLEDGED OR OTHERWISE TRANSFERRED, ONLY (I) TO
A PERSON WHOM THE SELLER REASONABLY BELIEVES IS A QUALIFIED INSTITUTIONAL
BUYER (AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT) IN A TRANSACTION
MEETING THE REQUIREMENTS OF RULE 144A,

<PAGE>

                                                                   19

(II) PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT
PROVIDED BY RULE 144 THEREUNDER (IF AVAILABLE) OR (III) PURSUANT TO AN
EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT, IN EACH OF CASES
(I) THROUGH (III) IN ACCORDANCE WITH ANY APPLICABLE SECURITIES LAWS OF ANY
STATE OF THE UNITED STATES, AND (B) THE HOLDER WILL, AND EACH SUBSEQUENT
HOLDER IS REQUIRED TO, NOTIFY ANY PURCHASER OF THIS SECURITY AND ANY SHARES
OF COMMON STOCK ISSUABLE UPON THE CONVERSION THEREOF OF THE RESALE
RESTRICTIONS REFERRED TO IN (A) ABOVE.]

          [INCLUDE IF SECURITY IS A RESTRICTED GLOBAL SECURITY:

          THE SECURITIES EVIDENCED BY THIS GLOBAL SECURITY (OR ITS
PREDECESSOR) WERE ORIGINALLY ISSUED IN A TRANSACTION EXEMPT FROM REGISTRATION
UNDER THE UNITED STATES SECURITIES ACT OF 1933 (THE "SECURITIES ACT"), AND
SUCH SECURITIES AND THE COMMON STOCK ISSUABLE UPON THE CONVERSION THEREOF MAY
NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED IN THE ABSENCE OF SUCH
REGISTRATION OR IN A TRANSACTION EXEMPT FROM, OR NOT SUBJECT TO, THE
SECURITIES ACT.  EACH PURCHASER OF ANY BENEFICIAL INTEREST IN THE SECURITIES
IS HEREBY NOTIFIED THAT THE SELLER OF SUCH BENEFICIAL INTEREST MAY BE RELYING
ON THE EXEMPTION FROM THE PROVISIONS OF SECTION 5 OF THE SECURITIES ACT
PROVIDED BY RULE 144A THEREUNDER.

          EACH BENEFICIAL OWNER OF AN INTEREST IN ANY OF THE SECURITIES
EVIDENCED BY THIS GLOBAL SECURITY (INCLUDING ANY PARTICIPANT IN THE
DEPOSITARY HOLDING THE GLOBAL SECURITY THAT IS SHOWN AS HOLDING SUCH AN
INTEREST ON THE RECORDS OF SUCH DEPOSITARY AND EACH BENEFICIAL OWNER THAT
HOLDS THROUGH SUCH PARTICIPANT) AGREES FOR THE BENEFIT OF THE COMPANY THAT
(A) ANY BENEFICIAL INTEREST IN THE SECURITIES AND THE COMMON STOCK ISSUABLE
UPON THE CONVERSION THEREOF MAY BE OFFERED, RESOLD, PLEDGED OR OTHERWISE
TRANSFERRED, ONLY (I) TO A PERSON WHOM THE SELLER REASONABLY BELIEVES IS A
QUALIFIED INSTITUTIONAL BUYER (AS DEFINED IN RULE 144A UNDER THE SECURITIES
ACT) IN A TRANSACTION MEETING THE REQUIREMENTS OF RULE 144A, (II) PURSUANT TO
AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT PROVIDED BY RULE 144
THEREUNDER (IF AVAILABLE) OR (III) PURSUANT TO AN EFFECTIVE REGISTRATION

<PAGE>

                                                                   20

STATEMENT UNDER THE SECURITIES ACT, IN EACH OF CASES (I) THROUGH (III) IN
ACCORDANCE WITH ANY APPLICABLE SECURITIES LAWS OF ANY STATE OF THE UNITED
STATES, AND (B) THE BENEFICIAL OWNER WILL, AND EACH SUBSEQUENT BENEFICIAL
OWNER OF THIS SECURITY OR ANY SHARES OF COMMON STOCK ISSUABLE UPON CONVERSION
THEREOF IS REQUIRED TO, NOTIFY ANY PURCHASER OF ANY BENEFICIAL INTEREST IN
THE SECURITIES AND ANY SHARES OF COMMON STOCK ISSUABLE UPON CONVERSION
THEREOF FROM IT OF THE RESALE RESTRICTIONS REFERRED TO IN (A) ABOVE.]

          [INCLUDE IF SECURITY IS A GLOBAL SECURITY:

          THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE
INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A
DEPOSITARY OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE EXCHANGED IN WHOLE
OR IN PART FOR A SECURITY REGISTERED, AND NO TRANSFER OF THIS SECURITY IN
WHOLE OR IN PART MAY BE REGISTERED, IN THE NAME OF ANY PERSON OTHER THAN SUCH
DEPOSITARY OR A NOMINEE THEREOF, EXCEPT IN THE LIMITED CIRCUMSTANCES
DESCRIBED IN THE INDENTURE.

          UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED
REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION
("DTC"), NEW YORK, NEW YORK, TO THE COMPANY OR ITS AGENT FOR REGISTRATION OF
TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN
THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF DTC, AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER
ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC, ANY TRANSFER,
PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS
WRONGFUL BECAUSE THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST
HEREIN.]

                                   Affymetrix, Inc.

<PAGE>

                                                                   21

                      5% Convertible Subordinated Notes due 2006


                                             CUSIP No. [            ]

                                                     No. ____ U. S. $_________


          Affymetrix, Inc., a corporation duly organized and existing under
the laws of the State of Delaware (herein called the "Company", which term
includes any successor Person under the Indenture hereinafter referred to),
for value received, hereby promises to pay to ________, or registered
assigns, the principal sum of __________________ United States Dollars
(U.S.$________ ) on October 1, 2006 and to pay interest thereon from
September 22, 1999, or from the most recent Interest Payment Date to which
interest has been paid or duly provided for, semi-annually in arrears on
October 1 and April 1 in each year, commencing April 1, 2000, at the rate of
5% per annum, until the principal hereof is paid or made available for
payment.  The interest so payable, and punctually paid or duly provided for,
on any Interest Payment Date will, as provided in such Indenture, be paid to
the Person in whose name this Security (or one or more Predecessor
Securities) is registered at the close of business on the Regular Record Date
for such interest, which shall be the September 15 or March 15 (whether or
not a Business Day), as the case may be, next preceding such Interest Payment
Date.  Any such interest not so punctually paid or duly provided for will
forthwith cease to be payable to the Holder on such Regular Record Date and
may either be paid to the Person in whose name this Security (or one or more
Predecessor Securities) is registered at the close of business on a Special
Record Date for the payment of such Defaulted Interest to be fixed by the
Trustee, notice whereof shall be given to Holders of Securities not less than
10 days prior to such Special Record Date, or be paid at any time in any
other lawful manner not inconsistent with the requirements of any securities
exchange on which the Securities may be listed, and upon such notice as may
be required by such exchange, all as more fully provided in said Indenture.

          Payment of the principal of, premium, if any, and interest
(including payment of any Additional Interest) on this Security will be made
at the Corporate Trust Office, in such coin or currency of the United States
of America as at the time of payment is legal tender for payment of public
and private debts by a U.S. Dollar check drawn on an account maintained with
a bank in the Borough of Manhattan, The City of New York; PROVIDED, HOWEVER,
that upon written application by the Holder to the Security Registrar setting
forth wire instructions not later than 5 days prior to the relevant payment
date (in

<PAGE>

                                                                   22

the case of payment of principal) or not later than the relevant Record Date
(in the case of payment of interest), such Holder may receive payment by wire
transfer of Dollars to a U.S. Dollar account maintained by the payee with a
bank in the United States or in Europe and designated by the payee to the
Security Registrar. [Include if a Global Security--All payments by the Company
in respect of a Global Security shall be wire transfer.]

          Reference is hereby made to the further provisions of this Security
set forth on the reverse hereof, which further provisions shall for all
purposes have the same effect as if set forth at this place.

          Unless the certificate of authentication hereon has been executed
by the Trustee referred to on the reverse hereof by manual signature, this
Security shall not be entitled to any benefit under the Indenture or be valid
or obligatory for any purpose.

          IN WITNESS WHEREOF, the Company has caused this instrument to be
duly executed.

                                                AFFYMETRIX, INC.


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


          SECTION 2.03.  FORM OF REVERSE OF SECURITY.  This Security is one
of a duly authorized issue of Securities of the Company designated as its 5%
Convertible Subordinated Notes due 2006 (herein called the "Securities"),
limited in aggregate principal amount to U.S.$150,000,000, issued and to be
issued under an Indenture, dated as of September 22, 1999 (herein called the
"Indenture"), between the Company and The Bank of New York, as Trustee for
the Holders of Securities issued under said Indenture (herein called the
"Trustee", which term includes any successor trustee under the Indenture), to
which Indenture and all indentures supplemental thereto reference is hereby

<PAGE>

                                                                   23

made for a statement of the respective rights, limitations of rights, duties
and immunities thereunder of the Company, the Trustee, the holders of Senior
Indebtedness and the Holders of the Securities and of the terms upon which
the Securities are, and are to be, authenticated and delivered.

          Subject to and upon compliance with the provisions of the
Indenture, the Holder of this Security is entitled, at his option, at any
time on or before the close of business on the Business Day immediately
preceding October 1, 2006, or in case this Security or a portion hereof is
called for redemption, then in respect of this Security or such portion
hereof until and including, but (unless the Company defaults in making the
payment due upon redemption or is otherwise due) not after, the close of
business on the Business Day immediately preceding the Redemption Date or
Purchase Date, as the case may be, to convert this Security (or any portion
of the principal amount hereof which is U.S.$1,000 or an integral multiple
thereof), at the principal amount hereof, or of such portion, into fully paid
and non-assessable shares of Common Stock of the Company at a conversion
price equal to U.S.$123.00 aggregate principal amount of Securities for each
share of Common Stock (or at the current adjusted conversion price if an
adjustment has been made as provided in Article XIII of the Indenture) by
surrender of this Security, duly endorsed or assigned to the Company or in
blank, to the Company at its office or agency in the Borough of Manhattan,
The City of New York, accompanied by the conversion notice hereon executed by
the Holder hereof evidencing such Holder's election to convert this Security,
or if less than the entire principal amount hereof is to be converted, the
portion hereof to be converted, and, in case such surrender shall be made
during the period from the close of business on any Regular Record Date to
the opening of business on the corresponding Interest Payment Date (unless
this Security or the portion hereof being converted has been called for
redemption on a Redemption Date within such period between and including such
Regular Record Date and such Interest Payment Date), also accompanied by
payment in cash of an amount equal to the interest payable on such Interest
Payment Date on the principal amount of this Security then being converted.
Subject to the aforesaid requirement for payment of interest and, in the case
of a conversion after the close of business on any Regular Record Date and on
or before the corresponding Interest Payment Date, to the right of the Holder
of this Security (or any Predecessor Security) of record at such Regular
Record Date to receive an installment of interest (even if the Security has
been called for redemption on a Redemption Date within such period), no
payment or adjustment is to be made on conversion for interest accrued hereon
or for dividends on the Common Stock issued on conversion.  No fractions of
shares or scrip representing fractions of shares will be issued on
conversion, but instead of any fractional interest the Company shall pay a
cash adjustment or round up to the next higher whole share as provided in
Article XIII of the Indenture.  The conversion price is subject to adjustment
as provided in Article XIII of

<PAGE>

                                                                   24

the Indenture.  In addition, the Indenture provides that in case of certain
reclassifications, consolidations, mergers, sales or transfers of assets or
other transactions pursuant to which the Common Stock is converted into the
right to receive other securities, cash or other property, the Indenture
shall be amended automatically, without the consent of any Holders of
Securities, so that this Security, if then outstanding, will be convertible
thereafter, during the period this Security shall be convertible as specified
above, only into the kind and amount of securities, cash and other property
receivable upon the transaction by a holder of the number of shares of Common
Stock into which this Security might have been converted immediately prior to
such transaction.

          The Company will furnish to any Holder, upon request and without
charge, copies of the Certificate of Incorporation and By-laws of the Company
then in effect.  Any such request may be addressed to the Company.

          The Securities are subject to redemption at the option of the
Company upon not less than 30 days' or more than 60 days' notice by mail, as
a whole or from time to time in part, at any time on or after October 7, 2002
through September 30, 2003 at 102.50% of the principal amount, and
thereafter, at the following Redemption Prices (expressed as percentages of
the principal amount), if redeemed during the 12-month period beginning on
October 1 of the years indicated,

<TABLE>
<CAPTION>
                                         Redemption
        Year                                Price
        ----                             ----------
        <S>                              <C>
        2003  . . . . . . . . . .          101.67%

        2004  . . . . . . . . . .          100.83%

        2005 and thereafter . . .           100%
</TABLE>

together in the case of any such redemption with accrued and unpaid interest
to (but not including) the Redemption Date, but interest installments whose
Stated Maturity is on or prior to such Redemption Date will be payable to the
Holders of such Securities, or one or more Predecessor Securities, of record
at the close of business on the relevant Record Dates referred to on the face
hereof, all as provided in the Indenture.

          In certain circumstances involving a Change in Control, each Holder
shall have the right to require the Company to redeem all or part of its
Securities at a purchase

<PAGE>

                                                                   25

price equal to 100% of the principal amount thereof, together with accrued
and unpaid interest through the Purchase Date.  The Purchase Price is payable
in cash or, at the Company's option but subject to the satisfaction of
certain conditions set forth in the Indenture, in shares of Common Stock
valued at 95% of the average Closing Prices of the Common Stock for the five
Trading Days preceding and including the third Trading Day prior to the
Purchase Date.

          The Securities do not have the benefit of any sinking fund.

          In the event of redemption, conversion or purchase of this Security
in part only, a new Security or Securities for the unredeemed, unconverted or
unpurchased portion hereof will be issued in the name of the Holder hereof
upon the cancellation hereof.

          Subject to certain limitations in the Indenture, at any time when
the Company is not subject to Section 13 or 15(d) of the United States
Securities Exchange Act of 1934, as amended, upon the request of a Holder or
the holder of shares of Common Stock issued upon conversion thereof, the
Company will promptly furnish or cause to be furnished Rule 144A Information
(as defined below) to such Holder or such holder of shares of Common Stock
issued upon conversion, or to a prospective purchaser of any such security
designated by any such Holder or holder of shares of Common Stock, as the
case may be, to the extent required to permit compliance by such Holder or
holder of shares of Common Stock with Rule 144A under the United States
Securities Act of 1933 (the "Securities Act"), in connection with the resale
of any such security.  "Rule 144A Information" shall be such information as
is specified pursuant to Rule 144A(d)(4) under the Securities Act (or any
successor provision thereto).

          If this Security is a Transfer Restricted Security, then the Holder
of this Security [IF THIS SECURITY IS A GLOBAL SECURITY, THEN INSERT-
(including any Person that has a beneficial interest in this Security)]
and the Common Stock issuable upon conversion thereof is entitled to the
benefits of a Registration Rights Agreement, dated as of September 22, 1999
(the "Registration Rights Agreement") executed by the Company.  If a
Registration Default occurs (as defined in the Registration Rights Agreement
and in the Indenture), Additional Interest will accrue on this Security from
and including the day following such Registration Default to but excluding
the day on which such Registration Default has been cured.  Additional
Interest will be paid semi-annually in arrears, with the first semi-annual
payment due on the first Interest Payment Date in respect of the Securities
following the date on which such Additional Interest begins to accrue, and
will accrue at a rate per annum equal to an additional one-half of one
percent (0.50%) of the principal amount of the Securities.

<PAGE>

                                                                   26

          Whenever in this Security there is a reference, in any context, to
the payment of the principal of, premium, if any, or interest on, or in
respect of, any Security, such mention shall be deemed to include mention of
the payment of Additional Interest payable as described in the preceding
paragraph to the extent that, in such context, Additional Interest is, was or
would be payable in respect of such Security and express mention of the
payment of Additional Interest (if applicable) in any provisions of this
Security shall not be construed as excluding Additional Interest in those
provisions of this Security where such express mention is not made.

          The indebtedness evidenced by this Security is, to the extent
provided in the Indenture, subordinate and subject in right of payment to the
prior payment in full of all Senior Indebtedness, and this Security is issued
subject to the provisions of the Indenture with respect thereto.  Each Holder
of this Security, by accepting the same, (a) agrees to and shall be bound by
such provisions, (b) authorizes and directs the Trustee on his behalf to take
such action as may be necessary or appropriate to effectuate the
subordination so provided and (c) appoints the Trustee his attorney-in-fact
for any and all such purposes.

          If an Event of Default shall occur and be continuing, the principal
of all the Securities may be declared due and payable in the manner and with
the effect provided in Article V of the Indenture.

          The Indenture permits, with certain exceptions as therein provided,
the amendment thereof and the modification of the rights and obligations of
the Company and the rights of the Holders of the Securities under the
Indenture at any time by the Company and the Trustee with the written consent
of the Holders of a majority in aggregate principal amount of the Securities
at the time Outstanding.  The Indenture also contains provisions permitting
the Holders of a majority in aggregate principal amount of the Securities at
the time Outstanding, on behalf of the Holders of all the Securities, to
waive compliance by the Company with certain provisions of the Indenture and
certain past defaults under the Indenture and their consequences.   Any such
consent or waiver by the Holder of this Security shall be written, with a
copy delivered to the Trustee, and shall be conclusive and binding upon such
Holder and upon all future Holders of this Security and of any Security
issued upon the registration of transfer hereof or in exchange herefor or in
lieu hereof, whether or not notation of such consent or waiver is made upon
this Security.

          No reference herein to the Indenture and no provision of this
Security or of the Indenture shall alter or impair the obligation of the
Company, which is absolute and

<PAGE>

                                                                   27

unconditional, to pay the principal of, premium, if any, and interest on
(including Additional Interest) this Security at the times, place and rate,
and in the coin or currency,  herein prescribed or to convert this Security
as provided in the Indenture.

          As provided in the Indenture and subject to certain limitations
therein set forth, the transfer of this Security is registrable in the
Security Register, upon surrender of this Security for registration of
transfer at the Corporate Trust Office duly endorsed by, or accompanied by a
written instrument of transfer in form satisfactory to the Company and the
Security Registrar duly executed by, the Holder hereof or his attorney duly
authorized in writing, and thereupon one or more new Securities, of
authorized denominations and for the same aggregate principal amount, will be
issued to the designated transferee or transferees.

          The Securities are issuable only in registered form without coupons
in denominations of U.S.$1,000 and any integral multiple thereof.  As
provided in the Indenture and subject to certain limitations therein set
forth, Securities are exchangeable for a like aggregate principal amount of
Securities of a different authorized denomination, as requested by the Holder
surrendering the same.

          No service charge shall be made for any such registration of
transfer or exchange, but the Company may require payment of a sum sufficient
to cover any tax or other governmental charge payable in connection therewith.

          Prior to due presentment of this Security for registration of
transfer, the Company, the Trustee and any agent of the Company or the
Trustee may treat the Person in whose name this Security is registered as the
owner hereof for all purposes, whether or not payment of or on this Security
is overdue, and neither the Company, the Trustee nor any such agent shall be
affected by notice to the contrary.

          Interest on this Security shall be computed on the basis of a
360-day year of twelve 30-day months.

          All terms used in this Security which are defined in the Indenture
shall have the meanings assigned to them in the Indenture.

          THE INDENTURE AND THIS SECURITY SHALL BE GOVERNED BY AND CONSTRUED
IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD TO
CONFLICT OF LAWS PRINCIPLES.

<PAGE>

                                                                   28

          SECTION 2.04.  FORM OF TRUSTEE'S CERTIFICATE OF AUTHENTICATION.

          This is one of the Securities referred to in the within-mentioned
Indenture.

Dated:                   The Bank of New York, not in its
                         individual capacity but solely as
                         Trustee


                                                                          By
                                                        AUTHORIZED SIGNATORY

          SECTION 2.05.  FORM OF CONVERSION NOTICE.

                         CONVERSION NOTICE

To:  Affymetrix, Inc.

          The undersigned Holder of this Security hereby irrevocably
exercises the option to convert this Security, or the portion hereof (which
is U.S.$1,000 or an integral multiple thereof) below designated, at any time
following the date of original issuance thereof, into shares of Common Stock
in accordance with the terms of the Indenture referred to in this Security,
and directs that the shares issuable and deliverable upon conversion,
together with any check in payment for a fractional share and any Security
representing any unconverted principal amount hereof, be issued and delivered
to the registered owner hereof unless a different name has been provided
below.  If shares or any portion of this Security not converted 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 and is delivering
herewith a certificate in proper form certifying that the applicable
restrictions on transfer have been complied with. Any amount required to be
paid by the undersigned on account of interest accompanies this Security.

          The Applicant hereby agrees that, promptly after request of the
Company, he or it will furnish such proof in support of this certification as
the Company or the Security Registrar for the Common Stock may, from time to
time, request.

                                      Dated:
                                                      Signature*

<PAGE>

                                                                   29


                                                    Signature Guaranty

If shares or Securities are to be       Principal amount to be converted
registered in the name of a Person      (if less than all):
other than the Holder, please print     $    ,000
such Person's name and address:*


          Name                                Social Security or
                                   Taxpayer Identification Number


     Street Address



 City, State and Zip Code


* Signature(s) must be guaranteed by an eligible guarantor institution
(banks, stock brokers, savings and loan associations and credit unions with
membership in an approved signature guarantee medallion program) pursuant to
Securities and Exchange Commission Rule 17Ad-15 if shares of Common Stock are
to be delivered, or unconverted Securities are to be issued, other than to
and in the name of the registered owner.

          SECTION 2.06.  FORM OF PURCHASE NOTICE.

          ELECTION OF HOLDER TO REQUIRE PURCHASE

          1.  Pursuant to Section 14.01 of the Indenture, the undersigned
hereby elects to have this Security purchased by the Company.

          2.  The undersigned hereby directs the Trustee or the Company to
pay it or ________________ an amount in cash, or, at the Company's election,
Common Stock valued as set forth in the Indenture, equal to 100% of the
principal amount to be

<PAGE>

                                                                   30

purchased (as set forth below), plus interest accrued to the Purchase Date,
as provided in the Indenture.

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


                                    --------------------------------------
                                        Signature


                                    --------------------------------------
                                        Signature Guaranteed


Principal amount to be purchased (must be an integral multiple of U.S. $1,000):

Remaining principal amount following such purchase:

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

NOTICE:  The signature to the foregoing Election must correspond to the Name
as written upon the face of this Security in every particular, without
alteration or any change whatsoever.

          SECTION 2.07.  FORM OF CERTIFICATION.  Whenever any certification
is required to be given to evidence compliance with certain restrictions
relating to transfers of Restricted Securities contemplated by Section
3.05(b)(iv), Section 3.05(c) or Section 13.02, such certification shall be
provided substantially in the form of the following certificate, with only
such changes as shall be approved by the Company and the Initial Purchasers,

                                 TRANSFER CERTIFICATE

          The undersigned Holder hereby certifies with respect to
U.S.$________ principal amount of the above-captioned securities presented or
surrendered on the date

<PAGE>

                                                                       31

hereof (the "Surrendered Securities") for registration of transfer, or for
exchange or conversion where the securities issuable upon such exchange or
conversion are to be registered in a name other than that of the undersigned
Holder (each such transaction being a "transfer"), that such transfer
complies with the restrictive legend set forth on the face of the Surrendered
Securities for the reason checked below:

               The transfer of the Surrendered Securities complies with Rule 144
               under the U.S. Securities Act of 1933 (the "Securities Act"); or

               The transfer of the Surrendered Securities complies with
               Rule 144A under the Securities Act; or

               The transfer of the Surrendered Securities is pursuant to an
               effective registration statement under the Securities Act, the
               prospectus delivery requirements under the Securities Act have
               been satisfied with respect to such transfer, the undersigned
               Holder is named as a "Selling Securityholder" in the prospectus
               relating to such registration statement, or in amendments or
               supplements thereto, and the aggregate principal amount of
               Surrendered Securities transferred are all or a portion of the
               securities listed in such prospectus opposite the undersigned's
               name.

Dated:              *
*    To be dated the date of surrender.



                                        Signature

                              (If the registered owner is a corporation,
                              partnership or fiduciary, the title of the Person
                              signing on behalf of such registered owner must be
                              stated.)


                                     ARTICLE III

                                    THE SECURITIES

          SECTION 3.01.  TITLE AND TERMS.  The aggregate principal amount of

<PAGE>

                                                                       32

Securities which may be authenticated and delivered under this Indenture is
limited to U.S.$150,000,000, except for Securities authenticated and
delivered upon registration of transfer of, or in exchange for, or in lieu
of, other Securities pursuant to Sections 3.04, 3.05, 3.06, 9.06, 11.08,
13.02 or 14.06 and except for Securities which, pursuant to Section 3.03, are
deemed never to have been authenticated and delivered hereunder.

          The Stated Maturity of the Securities shall be October 1, 2006, and
they shall bear interest at the rate of 5% per annum, payable semi-annually
on October 1 and April 1 of each year commencing on April 1, 2000, until the
principal thereof is paid or made available for payment.

          Payment of the principal of, premium, if any, and interest
(including payment of any Additional Interest) on this Security will be made
at the Corporate Trust Office, in such coin or currency of the United States
of America as at the time of payment is legal tender for payment of public
and private debts by a U.S. Dollar check drawn on an account maintained with
a bank in the Borough of Manhattan, The City of New York; PROVIDED, HOWEVER,
that upon written application by the Holder to the Security Registrar setting
forth wire instructions not later than 15 days prior to the relevant payment
date (in the case of payment of principal) or not later than the relevant
Record Date (in the case of payment of interest), such Holder may receive
payment by wire transfer of Dollars to a U.S. Dollar account maintained by
the payee with a bank in the United States or in Europe and designated by the
payee to the Security Registrar.

          The Securities shall be redeemable by the Company as provided in
Article XI.

          The Securities shall be subordinated in right of payment to the
prior payment in full of Senior Indebtedness as provided in Article XII.

          The Securities shall be convertible as provided in Article XIII.

          The Securities shall be subject to purchase by the Company at the
option of the Holder as provided in Article XIV.

          SECTION 3.02.  DENOMINATIONS.  The Securities shall be issuable
only in registered form without coupons and only in denominations of
U.S.$1,000 and any integral multiple thereof.

<PAGE>
                                                                            33

          SECTION 3.03.  EXECUTION, AUTHENTICATION, DELIVERY AND DATING.  The
Securities shall be executed on behalf of the Company by any of its Chairman of
the Board, its Vice Chairman of the Board, its President or one of its Vice
Presidents.  The signature of any of these officers on the Securities may be
manual or facsimile.

          Securities bearing the manual or facsimile signatures of
individuals who were at any time the proper officers of the Company shall
bind the Company, notwithstanding that such individuals or any of them have
ceased to hold such offices prior to the authentication and delivery of such
Securities or did not hold such offices at the date of such Securities.

          At any time and from time to time after the execution and delivery of
this Indenture, the Company may deliver Securities of any series executed by the
Company to the Trustee for authentication, together with a Company Order for the
authentication and delivery of such Securities; and the Trustee in accordance
with such Company Order shall authenticate and deliver such Securities as in
this Indenture provided and not otherwise.

          Each Security shall be dated the date of its authentication.

          No Security shall be entitled to any benefit under this Indenture or
be valid or obligatory for any purpose unless there appears on such Security a
certificate of authentication substantially in the form provided for herein
executed by the Trustee by manual signature, and such certificate upon any
Security shall be conclusive evidence, and the only evidence, that such Security
has been duly authenticated and delivered hereunder.

     The Trustee shall have the right to decline to authenticate and deliver any
Securities under this Section if the Trustee, being advised by counsel,
determines that such action may not lawfully be taken or if the Trustee in good
faith shall determine that such action would expose the Trustee to personal
liability to existing Holders.

          SECTION 3.04.  GLOBAL AND NON-GLOBAL SECURITIES.  (a)   GLOBAL
SECURITIES.  (i)  Each Global Security authenticated under this Indenture shall
be registered in the name of the Depositary designated by the Company for such
Global Security or a nominee thereof and delivered to such Depositary or a
nominee thereof or custodian therefor, and each such Global Security shall
constitute a single Security for all purposes of this Indenture.

<PAGE>
                                                                            34

          (ii)  Notwithstanding any other provision in this Indenture, no Global
Security may be exchanged in whole or in part for Securities registered, and no
transfer of a Global Security in whole or in part may be registered, in the name
of any Person other than the Depositary for such Global Security or a nominee
thereof unless (A) such Depositary (1) has notified the Company and the Trustee
that it is unwilling or unable to continue as Depositary for such Global
Security or (2) has ceased to be a clearing agency registered as such under the
Exchange Act or announces an intention permanently to cease business or in fact
does so, in each case unless a successor Depositary is appointed by the Company,
(B) there shall have occurred and be continuing an Event of Default with respect
to such Global Security, or (C) the Company in its discretion at any time
determines not to have all the Securities represented by a Global Security.  Any
Global Security exchanged pursuant to clause (i) above shall be so exchanged in
whole and not in part and any Global Security exchanged pursuant to clause (ii)
or (iii) above may be exchanged in whole or from time to time in part as
directed by the Depositary.  Any Security issued in exchange for a Global
Security or any portion thereof shall be a Global Security; PROVIDED that any
such Security so issued that is registered in the name of a Person other than
the Depositary or a nominee thereof shall not be a Global Security.

          (iii)  If any Global Security is to be exchanged for other Securities
or cancelled in whole, it shall be surrendered by or on behalf of the Depositary
or its nominee to the Trustee, as Security Registrar, for exchange or
cancellation as provided in this Article III.  If any Global Security is to be
exchanged for other Securities or cancelled in part, or if another Security is
to be exchanged in whole or in part for a beneficial interest in any Global
Security, in each case, as provided in Section 3.05, then either (i) such Global
Security shall be so surrendered for exchange or cancellation as provided in
this Article III or (ii) the principal amount thereof shall be reduced or
increased by an amount equal to the portion thereof to be so exchanged or
cancelled, or equal to the principal amount of such other Security to be so
exchanged for a beneficial interest therein, as the case may be, by means of an
appropriate adjustment made on the records of the Trustee, as Security
Registrar, whereupon the Trustee, in accordance with the Applicable Procedures,
shall instruct the Depositary or its authorized representative to make a
corresponding adjustment to its records.  Upon any such surrender or adjustment
of a Global Security, the Trustee shall, subject to Section 3.05(c) and as
otherwise provided in this Article III, authenticate and deliver any Securities
issuable in exchange for such Global Security (or any portion thereof) to or
upon the order of, and registered in such names as may be directed by, the
Depositary or its authorized representative.  Upon the request of the Trustee in
connection with the occurrence of any of the events specified

<PAGE>
                                                                            35

in the preceding paragraph, the Company shall promptly make available to the
Trustee a reasonable supply of Securities that are not in the form of Global
Securities.  The Trustee shall be entitled to rely upon any order, direction
or request of the Depositary or its authorized representative which is given
or made pursuant to this Article III if such order, direction or request is
given or made in accordance with the Applicable Procedures.

          (iv)  Every Security authenticated and delivered upon registration of
transfer of, or in exchange for or in lieu of, a Global Security or any portion
thereof, whether pursuant to this Article III or otherwise, shall be
authenticated and delivered in the form of, and shall be, a Global Security,
unless such Security is registered in the name of a Person other than the
Depositary for such Global Security or a nominee thereof, in which case such
Security shall be authenticated and delivered in definitive, fully registered
form, without interest coupons.

          (v)  The Depositary or its nominee, as registered owner of a Global
Security, shall be the Holder of such Global Security for all purposes under the
Indenture and the Securities, and owners of beneficial interests in a Global
Security shall hold such interests pursuant to the Applicable Procedures.
Accordingly, any such owner's beneficial interest in a Global Security will be
shown only on, and the transfer of such interest shall be effected only through,
records maintained by the Depositary or its nominee or its Agent Members and
such owners of beneficial interests in a Global Security will not be considered
the owners or holders thereof.  Notwithstanding the foregoing, nothing herein
shall prevent the Company, the Trustee or any agent of the Company or the
Trustee from giving effect to any written certification, proxy or other
authorization furnished by the Depositary or such nominee, as the case may be,
or impair, as between the Depositary, its Agent Members and any other person on
whose behalf an Agent Member may act, the operation of customary practices of
such Persons governing the exercise of the rights of a holder of any Security.

          SECTION 3.05.  REGISTRATION; REGISTRATION OF TRANSFER AND EXCHANGE.
(a)  The Company shall cause to be kept at the Corporate Trust Office of the
Trustee a register (the register maintained in such office and in any other
office or agency designated pursuant to Section 10.02 being herein sometimes
collectively referred to as the "Security Register") in which, subject to such
reasonable regulations as it may prescribe, the Company shall provide for the
registration of Securities and of transfers and exchanges thereof.  The Trustee
is hereby appointed "Security Registrar" for the purpose of registering
Securities and transfers and exchanges thereof as herein provided.  Upon
surrender for registration of transfer or exchange of any Security at an office
or agency of the Company designated pursuant to Section 10.02 for such purpose,
accompanied by a written instrument of transfer or exchange in the form provided
by the

<PAGE>
                                                                            36

Company, the Company shall execute, and the Trustee shall authenticate and
deliver, in the name of the designated transferee or transferees, one or more
new Securities of any authorized denominations and of a like aggregate
principal amount.

          (b)  Notwithstanding any other provisions of this Indenture or the
Securities, transfers and exchanges of Securities and beneficial interests in a
Global Security of the kinds specified in this Section 3.05(b) shall be made
only in accordance with this Section 3.05(b).

          (i) TRANSFER OF GLOBAL SECURITY.  Other than as set forth in
     Section 3.04(a), a Global Security may not be transferred, in whole or in
     part, to any Person other than the Depositary or a nominee thereof, and no
     such transfer to any such other Person may be registered; PROVIDED that
     this Section 3.05(b)(i) shall not prohibit any transfer of a Security that
     is issued in exchange for a Global Security but is not itself a Global
     Security.  No transfer of a Security to any Person shall be effective under
     this Indenture or the Securities unless and until such Security has been
     registered in the name of such Person.  Nothing in this Section 3.05(b)(i)
     shall prohibit or render ineffective any transfer of a beneficial interest
     in a Global Security effected in accordance with the other provisions of
     this Section 3.05(b).

          (ii) TRANSFER OF BENEFICIAL INTERESTS IN THE GLOBAL SECURITY.
     Transfer of beneficial interests in the Global Security shall be effected
     through the Depositary, in accordance with this Indenture (including
     applicable restrictions on transfer set forth herein, if any) and the
     procedures of the Depositary therefor, if applicable.

          (iii) OTHER EXCHANGES.  In the event that a Global Security or any
     portion thereof is exchanged for Securities other than Global Securities,
     such other Securities may in turn be exchanged (on transfer or otherwise)
     for Securities that are not Global Securities or for beneficial interests
     in a Global Security (if any is then outstanding) only in accordance with
     such procedures, which shall be substantially consistent with the
     provisions of this Section 3.05(b) (including the certification
     requirements set forth on the reverse of the Security intended to insure
     that transfers of beneficial interests in a Global Security comply with
     Rule 144A or Rule 144 under the Securities Act, as the case may be) and any
     Applicable Procedures, as may be from time to time adopted by the Company
     and the Trustee.

          (iv) TRANSFER AND EXCHANGE OF DEFINITIVE SECURITIES.  When definitive
     Securities are

<PAGE>
                                                                            37

     presented to the Security Registrar with a request:

               (A) to register the transfer of such definitive Securities; or

               (B) to exchange such definitive Securities for an equal principal
          amount of definitive Securities of other authorized denominations, the
          Security Registrar shall register the transfer or make the exchange as
          requested if its reasonable requirements for such transaction are met;
          PROVIDED, HOWEVER, that the definitive Securities surrendered for
          transfer or exchange:

                    (x) shall be duly endorsed or accompanied by a written
               instrument of transfer in form reasonably satisfactory to the
               Company and the Security Registrar, duly executed by the Holder
               thereof or his attorney duly authorized in writing; and

                    (y) are being transferred or exchanged pursuant to an
               effective registration statement under the Securities Act,
               pursuant to Section 3.05(b)(v), or pursuant to clause (1), (2) or
               (3) below, and are accompanied by the following additional
               information and documents, as applicable:

                         (1) if such definitive Securities are being delivered
                    to the Security Registrar by a Holder for registration in
                    the name of such Holder, without transfer, a certification
                    from such Holder to that effect (in the form set forth in
                    Section 2.07); or

                         (2) if such definitive Securities are being transferred
                    to the Company, a certification to that effect (in the form
                    set forth in Section 2.07); or

                         (3) if such definitive Securities are being transferred
                    pursuant to an exemption from registration in accordance
                    with Rule 144, (i) a certification to that effect (in the
                    form set forth in Section 2.07) and (ii) if the Company or
                    Security Registrar so requests, an opinion of counsel or
                    other evidence reasonably satisfactory to them as to the
                    compliance with the restrictions set forth in the legend set
                    forth in Section 2.02.

<PAGE>
                                                                            38

          (v) RESTRICTIONS ON TRANSFER OF A DEFINITIVE SECURITY FOR A BENEFICIAL
     INTEREST IN A GLOBAL SECURITY.  A definitive Security may not be exchanged
     for a beneficial interest in a Global Security except upon satisfaction of
     the requirements set forth below.  Upon receipt by the Trustee of a
     definitive Security, duly endorsed or accompanied by appropriate
     instruments of transfer, in form satisfactory to the Trustee, together
     with:

               (A) certification in the form set forth on the reverse of the
          Security that such definitive Security is being transferred to a
          Qualified Institutional Buyer in accordance with Rule 144A; and

               (B) written instructions directing the Trustee to make, or to
          direct the Securities Registrar to make, an adjustment on its books
          and records with respect to such Global Security to reflect an
          increase in the aggregate principal amount of the Securities
          represented by the Global Security, such instructions to contain
          information regarding the Depositary account to be credited with such
          increase,

     then the Trustee shall cancel such definitive Security and cause, or direct
     the Securities Registrar to cause, in accordance with the standing
     instructions and procedures existing between the Depositary and the
     Securities Registrar, the aggregate principal amount of Securities
     represented by the Global Security to be increased by the aggregate
     principal amount of the definitive Security to be exchanged and shall
     credit or cause to be credited to the account of the Person specified in
     such instructions a beneficial interest in the Global Security equal to the
     principal amount of the definitive Security so cancelled.  If no Global
     Securities are then outstanding, the Company shall issue and the Trustee
     shall authenticate, upon written order of the Company in the form of an
     Officers' Certificate, a new Global Security in the appropriate principal
     amount.

          (c)  Subject to the succeeding paragraph, every Security shall be
subject to the restrictions on transfer provided in the legends required by
Section 2.02 to be applied to such Security.  Whenever any Security is presented
or surrendered for registration of transfer or for exchange for a Security
registered in a name other than that of the Holder, such Security must be
accompanied by a certificate in substantially the form set forth in
Section 2.07, dated the date of such surrender and signed by the Holder of such
Security, as to compliance with such restrictions on transfer.  The Security
Registrar shall not be required to accept for such registration of transfer or
exchange any Security not so accompanied by a properly completed certificate.

<PAGE>
                                                                            39

          (d)  The restrictions imposed by the legend set forth in the first or
fourth paragraph, as the case may be, of Section 2.02 upon the transferability
of any Security shall cease and terminate when such Security has been sold
pursuant to an effective registration statement under the Securities Act,
transferred in compliance with Rule 144 under the Securities Act (or any
successor provision thereto), or after the second anniversary of the original
issuance date of the Security (or such earlier date after which the Security may
be freely transferred without registration under the Securities Act or without
being subject to transfer restrictions pursuant to the Securities Act, as may be
provided in Rule 144(k) under the Securities Act (or any successor provision
thereto) or otherwise).  Any Security as to which such restrictions on transfer
shall have expired in accordance with their terms or shall have terminated may,
upon surrender of such Security for exchange to the Security Registrar in
accordance with the provisions of this Section 3.05 (accompanied, in the event
that such restrictions on transfer have terminated by reason of a transfer in
compliance with Rule 144 or any successor provision, by an opinion of counsel
having substantial experience in practice under the Securities Act and otherwise
reasonably acceptable to the Company, addressed to the Company and in form
acceptable to the Company, to the effect that the transfer of such Security has
been made in compliance with Rule 144 or such successor provision), be exchanged
for a new Security, of like tenor and aggregate principal amount, which shall
not bear the restrictive legend set forth in the first paragraph of
Section 2.02.  The Company shall inform the Trustee of the effective date of any
registration statement registering the Securities under the Securities Act.  The
Trustee shall not be liable for any action taken or omitted to be taken by it in
good faith in accordance with the aforementioned opinion of counsel or notice of
an effective registration statement.

          (e)  As used in the preceding two paragraphs (c) and (d) of this
Section 3.05, the term "transfer" encompasses any sale, pledge, transfer,
hypothecation or other disposition of any Security.

          (f)  No service charge shall be made for any registration of transfer
or exchange of Securities, but the Company may require payment of a sum
sufficient to cover any tax or other governmental charge that may be imposed in
connection with any registration of transfer or exchange of Securities, other
than exchanges pursuant to Section 3.04, 9.06, 11.08, 13.02 or 14.06 not
involving any transfer.

          (g)  The Company shall not be required (i) to issue, register the
transfer of or exchange any Security during a period beginning at the opening of
business 15 days

<PAGE>
                                                                            40

before the day of the mailing of a notice of redemption of Securities
selected for redemption under Section 11.04 and ending at the close of
business on the day of such mailing, or (ii) to register the transfer of or
exchange any Security so selected for redemption in whole or in part, except
the unredeemed portion of any Security being redeemed in part.

          SECTION 3.06.  MUTILATED, DESTROYED, LOST AND STOLEN SECURITIES.  If
any mutilated Security is surrendered to the Trustee, the Company shall execute
and the Trustee shall authenticate and deliver in exchange therefor a new
Security of like tenor and principal amount and bearing a number not
contemporaneously outstanding.

          If there shall be delivered to the Company and the Trustee
(i) evidence to their satisfaction of the destruction, loss or theft of any
Security and (ii) such security or indemnity as may be required by them to save
each of them and any agent of either of them harmless, then, in the absence of
written notice to the Company or the Trustee that such Security has been
acquired by a bona fide purchaser, the Company shall execute and the Trustee
shall authenticate and deliver, in lieu of any such destroyed, lost or stolen
Security, a new Security of like tenor and principal amount and bearing a number
not contemporaneously outstanding.

          In case any such mutilated, destroyed, lost or stolen Security has
become or is about to become due and payable, the Company in its discretion, but
subject to any conversion rights, may, instead of issuing a new Security, pay
such Security.

          Upon the issuance, authentication and delivery by the Trustee of any
new Security under this Section 3.06, the Company may require the payment of a
sum sufficient to cover any tax or other governmental charge that may be imposed
in relation thereto and any other expenses (including the fees and expenses of
the Trustee) connected therewith.

          Every new Security issued, authenticated and delivered by the Trustee
pursuant to this Section 3.06 in lieu of any destroyed, lost or stolen Security
shall constitute an original additional contractual obligation of the Company,
whether or not the destroyed, lost or stolen Security shall be at any time
enforceable by anyone, and shall be entitled to all the benefits of this
Indenture equally and proportionately with any and all other Securities duly
issued hereunder.

          The provisions of this Section are exclusive and shall preclude (to
the extent lawful) all other rights and remedies with respect to the replacement
or payment of mutilated, destroyed, lost or stolen Securities.

<PAGE>
                                                                            41

          SECTION 3.07.  PAYMENT OF INTEREST; INTEREST RIGHTS PRESERVED.
Interest on any Security which is payable, and is punctually paid or duly
provided for, on any Interest Payment Date shall be paid to the Person in whose
name that Security (or one or more Predecessor Securities) is registered at the
close of business on the Regular Record Date for payment of such interest.

          If the Company shall be required by law to deduct any taxes from any
sum of interest payable hereunder to a Holder, (i) the Company shall make such
deductions and shall pay the full amount deducted to the relevant taxing
authority in accordance with applicable law and (ii) the amount of such
deduction shall be treated for purposes hereof as a payment of interest.

          Any interest on any Security which is payable, but is not punctually
paid or duly provided for, on any Interest Payment Date (herein called
"Defaulted Interest") shall forthwith cease to be payable to the Holder on the
relevant Regular Record Date by virtue of having been such Holder, and such
Defaulted Interest may be paid by the Company, at its election in each case, as
provided in clause (1) or (2) below:

          (1) The Company may elect to make payment of any Defaulted Interest to
     the Persons in whose names the Securities (or their respective Predecessor
     Securities) are registered at the close of business on a Special Record
     Date for the payment of such Defaulted Interest, which shall be fixed in
     the following manner.  The Company shall notify the Trustee in writing of
     the amount of Defaulted Interest proposed to be paid on each Security and
     the date of the proposed payment, and at the same time the Company shall
     deposit with the Trustee an amount of money equal to the aggregate amount
     proposed to be paid in respect of such Defaulted Interest or shall make
     arrangements satisfactory to the Trustee for such deposit prior to the date
     of the proposed payment, such money when deposited to be held in trust for
     the benefit of the Persons entitled to such Defaulted Interest as in this
     clause (1) provided.  Thereupon, the Trustee shall, on behalf of, and upon
     the instructions of, the Company, fix a Special Record Date for the payment
     of such Defaulted Interest which shall be not more than 15 days and not
     less than 10 days prior to the date of the proposed payment and not less
     than 10 days after the receipt by the Trustee of the notice of the proposed
     payment.  The Trustee, in the name and at the expense of the Company, shall
     forward a notice prepared by the Company of the proposed payment of such
     Defaulted Interest and the Special Record Date therefor to be mailed,

<PAGE>
                                                                            42

     first-class postage prepaid, to each Holder at his address as it appears in
     the Security Register, not less than 10 days prior to such Special Record
     Date at the expense of the Company.  Notice of the proposed payment of such
     Defaulted Interest and the Special Record Date therefor having been so
     mailed, such Defaulted Interest shall be paid to the Persons in whose names
     the Securities (or their respective Predecessor Securities) are registered
     at the close of business on such Special Record Date and shall no longer be
     payable pursuant to the following clause (2).

          (2) The Company may make payment of any Defaulted Interest in any
     other lawful manner not inconsistent with the requirements of any
     securities exchange on which the Securities may be listed, and upon such
     notice as may be required by such exchange, if, after written notice given
     by the Company to the Trustee of the proposed payment pursuant to this
     clause (2), such manner of payment shall be deemed practicable by the
     Trustee.

          Subject to the foregoing provisions of this Section, each Security
delivered under this Indenture upon registration of transfer of or in exchange
for or in lieu of any other Security shall carry the rights to interest accrued
and unpaid, and to accrue, which were carried by such other Security.

          In the case of any Security which is converted after any Regular
Record Date and on or prior to the corresponding Interest Payment Date, interest
on such Security whose Stated Maturity is on such Interest Payment Date shall be
deemed to continue to accrue and shall be payable on such Interest Payment Date
notwithstanding such conversion and notwithstanding that such Security may have
been called for redemption on a Redemption Date within such period, and such
interest (whether or not punctually paid or duly provided for) shall be paid to
the Person in whose name that Security (or one or more Predecessor Securities)
is registered at the close of business on such Regular Record Date.  Except as
otherwise expressly provided in the immediately preceding sentence, in the case
of any Security which is converted, interest whose Stated Maturity is after the
date of conversion of such Security shall not be payable.

          SECTION 3.08.  PERSONS DEEMED OWNERS.  Prior to due presentment of a
Security for registration of transfer, the Company, the Trustee and any agent of
the Company or the Trustee may treat the Person in whose name such Security is
registered in the Security Register as the owner of such Security for the
purpose of receiving payment of principal of, premium, if any, and (subject to
Section 3.07) interest on such Security and for all other purposes whatsoever,
whether or not such Security be overdue, and neither the Company, the Trustee
nor any agent of the Company or the Trustee shall be affected by notice to the
contrary.

<PAGE>

                                                                          43


          SECTION 3.09.  CANCELLATION.  All Securities surrendered for
payment, redemption, purchase, registration of transfer or exchange or
conversion shall, if surrendered to any Person other than the Trustee, be
delivered to the Trustee and shall be promptly cancelled by it.  The Company
may at any time deliver to the Trustee for cancellation any Securities
previously authenticated and delivered hereunder which the Company may have
acquired in any manner whatsoever, and all Securities so delivered shall be
promptly cancelled by the Trustee.  No Securities shall be authenticated in
lieu of or in exchange for any Securities cancelled as provided in this
Section, except as expressly permitted by this Indenture.  All cancelled
Securities held by the Trustee shall be disposed of as directed by a Company
Order; PROVIDED HOWEVER, the Trustee shall not be required to destroy such
cancelled Securities..

          SECTION 3.10.  COMPUTATION OF INTEREST.  Interest on the Securities
shall be computed on the basis of a 360-day year of twelve 30-day months.

          SECTION 3.11  CUSIP NUMBERS.  The Company in issuing the Securities
may use "CUSIP" numbers (if then generally in use), and, if so, the Trustee
shall use "CUSIP" numbers in notices of redemption as a convenience to
Holders; PROVIDED that any such notice may state that no representation is
made as to the correctness of such numbers either as printed on the
Securities or as contained in any notice of a redemption and that reliance
may be placed only on the other identification numbers printed on the
Securities, and any such redemption shall not be affected by any defect in or
omission of such numbers.  The Company will promptly notify the Trustee of
any change in the "CUSIP" numbers.

                                      ARTICLE IV

                              SATISFACTION AND DISCHARGE

          SECTION 4.01.  SATISFACTION AND DISCHARGE OF INDENTURE.  This
Indenture shall upon Company Request cease to be of further effect (except as
to any surviving rights of conversion, registration of transfer or exchange
of Securities herein expressly provided for), and the Trustee, at the expense
of the Company, shall execute proper instruments acknowledging satisfaction
and discharge of this Indenture, when

          (1)  either

               (A) all Securities theretofore authenticated and delivered
          (other


<PAGE>

                                                                          44


          than (i) Securities which have been destroyed, lost or stolen
          and which have been replaced or paid as provided in Section 3.06 and
          (ii) Securities for whose payment money has theretofore been
          deposited in trust or segregated and held in trust by the Company
          and thereafter repaid to the Company or discharged from such trust,
          as provided in Section 10.03) have been delivered to the Trustee
          for cancellation;

               (B) all such Securities not theretofore delivered to the
          Trustee for cancellation

                    (i) have become due and payable, or

               (ii) will become due and payable at their Stated Maturity within
                one year, or

               (iii) are to be called for redemption within one year under
               arrangements satisfactory to the Trustee for the giving of
               notice of redemption by the Trustee in the name, and at the
               expense, of the Company,

and the Company, in the case of (i), (ii) or (iii) above, has deposited or
caused to be deposited irrevocably with the Trustee as trust funds in trust
for the benefit of Holders of Outstanding Securities in an amount sufficient
to pay and discharge the entire indebtedness on such Securities not
theretofore delivered to the Trustee for cancellation, for principal (and
premium, if any) and interest to the date of such deposit (in the case of
Securities which have become due and payable) or to the Stated Maturity or
Redemption Date, as the case may be;

               (2)  the Company has paid or caused to be paid all other sums
     payable hereunder by the Company;

               (3)  the Company has delivered to the Trustee an Officers'
     Certificate and an Opinion of Counsel, each stating that all conditions
     precedent herein provided for relating to the satisfaction and discharge
     of this Indenture have been complied with; and

               (4)  no Event of Default which, with notice or lapse of time,
     or both, would become an Event of Default with respect to the Securities
     shall have occurred


<PAGE>

                                                                          45


     and be continuing on the date of such deposit.

Notwithstanding the satisfaction and discharge of this Indenture, the
obligations of the Company to the Trustee under Section 6.07, the obligations
of the Company to any Authenticating Agent under Section 6.14 and, if money
shall have been deposited with the Trustee pursuant to subclause (B) of
clause (1) of this Section, the obligations of the Trustee under Section 4.02
and the last paragraph of Section 10.03 shall survive.

          SECTION 4.02.  APPLICATION OF TRUST MONEY.  Subject to the
provisions of the last paragraph of Section 10.03, all money deposited with
the Trustee pursuant to Section 4.01 shall be held in trust and applied by
it, in accordance with the provisions of the Securities and this Indenture,
to the payment, either directly or through any Paying Agent (including the
Company acting as its own Paying Agent) as the Trustee may determine, to the
Persons entitled thereto, of the principal (and premium, if any) and interest
for whose payment such money has been deposited with the Trustee.  All moneys
deposited with the Trustee pursuant to Section 4.01 (and held by it or any
Paying Agent) for the payment of Securities subsequently converted shall be
returned to the Company upon Company Request.

                                      ARTICLE V

                                       REMEDIES

          SECTION 5.01.  EVENTS OF DEFAULT.  "Event of Default", wherever
used herein, means any one of the following events (whatever the reason for
such Event of Default and whether it shall be occasioned by the provisions of
Article XII or be voluntary or involuntary or be effected by operation of law
or pursuant to any judgment, decree or order of any court or any order, rule
or regulation of any administrative or governmental body):

          (1)  default in the payment of any interest (including Additional
     Interest) upon any Security when it becomes due and payable, and
     continuance of such default for a period of 30 days (whether or not such
     payment is prohibited by the provisions of Article XII); or

          (2)  default in the payment of the principal of (or premium, if any,
     on) any Security at its Maturity (whether or not such payment is
     prohibited by the provisions of Article XII); or


<PAGE>

                                                                          46


          (3)  failure by the Company to provide the notice of a Change in
     Control in accordance with Section 14.03 or default in the payment of the
     Purchase Price in respect of any Security on the Purchase Date therefor
     (whether or not such payment is prohibited by the provisions of
     Article XII); or

          (4)  default in the performance, or breach, of any covenant or
     warranty of the Company in this Indenture (other than a covenant or
     warranty a default in whose performance or whose breach is elsewhere in
     this Section specifically dealt with), and continuance of such default or
     breach for a period of 60 days after there has been given, by registered
     or certified mail, to the Company by the Trustee or to the Company and the
     Trustee by the Holders of at least 25% in principal amount of the
     Outstanding Securities a written notice specifying such default or breach
     and requiring it to be remedied and stating that such notice is a "Notice
     of Default" hereunder; or

          (5)  a default under any bonds, debentures, notes or other evidences
     of indebtedness for money borrowed by the Company or a Subsidiary or under
     any mortgages, indentures or instruments under which there may be issued
     or by which there may be secured or evidenced any indebtedness for money
     borrowed by the Company or a Subsidiary, whether such indebtedness now
     exists or shall hereafter be created which indebtedness, individually or
     in the aggregate, has a principal amount outstanding in excess of
     U.S.$10,000,000, which default shall constitute a failure to pay any
     portion of the principal of such indebtedness when due and payable after
     the expiration of any applicable grace or cure period with respect thereto
     or shall have resulted in such indebtedness becoming or being declared due
     and payable prior to the date on which it would otherwise have become due
     and payable, without such indebtedness having been discharged, or such
     acceleration having been rescinded or annulled, within a period of 30 days
     after there shall have been given, by registered or certified mail, to the
     Company by the Trustee or to the Company and the Trustee by the Holders of
     at least 25% in principal amount of the Outstanding Securities a written
     notice specifying such default and requiring the Company to cause such
     indebtedness to be discharged or cause such acceleration to be rescinded
     or annulled and stating that such notice is a "Notice of Default"
     hereunder; or

          (6)  the entry by a court having jurisdiction in the premises of (A) a
     decree or order for relief in respect of the Company or a Subsidiary in an
     involuntary case or proceeding under any applicable Federal or State
     bankruptcy, insolvency,


<PAGE>

                                                                          47


     reorganization or other similar law or (B) a decree or order adjudging
     the Company or a Subsidiary bankrupt or insolvent, or approving as
     properly filed a petition seeking reorganization, arrangement, adjustment
     or composition of or in respect of the Company or a Subsidiary under any
     applicable Federal or State law, or appointing a custodian, receiver,
     liquidator, assignee, trustee, sequestrator or other similar official of
     the Company or a Subsidiary or of any substantial part of their
     respective properties, or ordering the winding up or liquidation of the
     affairs of the Company or a Subsidiary, and the continuance of any such
     decree or order for relief or any such other decree or order unstayed and
     in effect for a period of 60 consecutive days; or

          (7)  the commencement by the Company or a Subsidiary of a voluntary
     case or proceeding under any applicable Federal or State bankruptcy,
     insolvency, reorganization or other similar law or of any other case or
     proceeding to be adjudicated a bankrupt or insolvent, or the consent by
     either the Company or a Subsidiary to the entry of a decree or order for
     relief in respect of the Company or a Subsidiary in an involuntary case or
     proceeding under any applicable Federal or State bankruptcy, insolvency,
     reorganization or other similar law or to the commencement of any
     bankruptcy or insolvency case or proceeding against either the Company or
     a Subsidiary, or the filing by either the Company or a Subsidiary of a
     petition or answer or consent seeking reorganization or relief under any
     applicable Federal or State law, or the consent by either the Company or a
     Subsidiary to the filing of such petition or to the appointment of or
     taking possession by a custodian, receiver, liquidator, assignee, trustee,
     sequestrator or other similar official of the Company or a Subsidiary or
     of any substantial part of their respective properties, or the making by
     either the Company or a Subsidiary of an assignment for the benefit of
     creditors, or the admission by either the Company or a Subsidiary in
     writing of an inability to pay the debts of either the Company or a
     Subsidiary generally as they become due, or the taking of corporate action
     by the Company or a Subsidiary in furtherance of any such action.

          SECTION 5.02.  ACCELERATION OF MATURITY; RESCISSION AND ANNULMENT.
If an Event of Default (other than an Event of Default specified in Section
5.01(6) or 5.01(7)) occurs and is continuing, then in every such case the
Trustee or the Holders of not less than 25% in principal amount of the
Outstanding Securities may declare the principal of all the Securities to be
due and payable immediately, by a notice in writing to the Company (and to
the Trustee if given by Holders), and upon any such declaration such
principal and any accrued interest (including Additional Interest) thereon
shall become immediately due and payable.  If an Event of Default specified
in Section 5.01(6) or 5.01(7) occurs, the principal of, and accrued interest
(including Additional Interest) on,


<PAGE>

                                                                          48


all the Securities shall automatically, and without any declaration or
other action on the part of the Trustee or any Holder, become immediately due
and payable.

          At any time after such a declaration of acceleration has been made
and before a judgment or decree for payment of the money due has been
obtained by the Trustee as hereinafter in this Article V provided, the
Holders of a majority in principal amount of the Outstanding Securities, by
written notice to the Company and the Trustee, may rescind and annul such
declaration and its consequences if

          (1) the Company has paid or deposited with the Trustee a sum
     sufficient to pay

               (A) all overdue interest (including Additional Interest) on all
          Securities,

               (B) the principal of (and premium, if any, on) any Securities
          which have become due otherwise than by such declaration of
          acceleration and interest thereon at the rate borne by the
          Securities,

               (C) to the extent that payment of such interest is lawful,
          interest upon overdue interest at the rate borne by the Securities,
          and

               (D) all sums paid or advanced by the Trustee hereunder and the
          reasonable compensation, expenses, disbursements and advances of the
          Trustee, its agents and counsel;

     and

          (2) all Events of Default, other than the nonpayment of the principal
     of Securities which have become due solely by such declaration of
     acceleration, have been cured or waived as provided in Section 5.13.

No such rescission shall affect any subsequent default or impair any right
consequent thereon.

          SECTION 5.03.  COLLECTION OF INDEBTEDNESS AND SUITS FOR ENFORCEMENT
BY TRUSTEE.  If


<PAGE>

                                                                          49


          (1) default is made in the payment of any interest on any Security
     when such interest becomes due and payable and such default continues for
     a period of 30 days, or

          (2) default is made in the payment of the principal of (or premium,
     if any, on) any Security at the Maturity thereof,

the Trustee is authorized to recover judgment in its own name and as trustee
of an express trust against the Company for the whole amount then due and
payable on such Securities for principal (and premium, if any) and interest,
and, to the extent that payment of such interest shall be legally
enforceable, interest on any overdue principal (and premium, if any) and on
any overdue interest, at the rate borne by the Securities, and, in addition
thereto, such further amount as shall be sufficient to cover the costs and
expenses of collection, including the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel.

          If an Event of Default occurs and is continuing, the Trustee may in
its discretion proceed to protect and enforce its rights and the rights of
the Holders by such appropriate judicial proceedings as the Trustee shall
deem most effectual to protect and enforce any such rights, whether for the
specific enforcement of any covenant or agreement in this Indenture or in aid
of the exercise of any power granted herein, or to enforce any other proper
remedy.

          SECTION 5.04.  TRUSTEE MAY FILE PROOFS OF CLAIM.  In case of any
judicial proceeding relative to the Company (or any other obligor upon the
Securities), its property or its creditors, the Trustee shall be entitled and
empowered, by intervention in such proceeding or otherwise,

          (1) to file and prove a claim for the whole amount of principal and
     interest owing and unpaid in respect of the Securities and to file such
     other papers or documents as may be necessary or advisable in order to
     have the claims of the Trustee (including any claim for the reasonable
     compensation, expenses, disbursements and advances of the Trustee, its
     agents and counsel) and of the Holders allowed in such judicial
     proceeding, and

          (2) to collect and receive any moneys or other property payable or
     deliverable on any such claim and to distribute the same;

and any custodian, receiver, assignee, trustee, liquidator, sequestrator or
other similar


<PAGE>

                                                                          50


official in any such judicial proceeding is hereby authorized by each Holder
to make such payments to the Trustee and, in the event that the Trustee shall
consent to the making of such payments directly to the Holders, to pay to the
Trustee any amount due it for the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel, and any
other amounts due the Trustee under Section 6.07.

          No provision of this Indenture shall be deemed to authorize the
Trustee to authorize or consent to or accept or adopt on behalf of any Holder
any plan of reorganization, arrangement, adjustment or composition affecting
the Securities or the rights of any Holder thereof or to authorize the
Trustee to vote in respect of the claim of any Holder in any such proceeding;
PROVIDED, HOWEVER, that the Trustee may, on behalf of the Holders, vote for
the election of a trustee in bankruptcy or similar official and be a member
of a creditors' or other similar committee.

          SECTION 5.05.  TRUSTEE MAY ENFORCE CLAIMS WITHOUT POSSESSION OF
SECURITIES.  All rights of action and claims under this Indenture or the
Securities may be prosecuted and enforced by the Trustee without the
possession of any of the Securities or the production thereof in any
proceeding relating thereto, and any such proceeding instituted by the
Trustee shall be brought in its own name as trustee of an express trust, and
any recovery of judgment shall, after provision for the payment of the
reasonable compensation, expenses, disbursements and advances of the Trustee,
its agents and counsel, be for the ratable benefit of the Holders of the
Securities in respect of which such judgment has been recovered.

          SECTION 5.06.  APPLICATION OF MONEY COLLECTED.  Any money collected
by the Trustee pursuant to this Article V shall be applied in the following
order, at the date or dates fixed by the Trustee and, in case of the
distribution of such money on account of principal (or premium, if any) or
interest, upon presentation of the Securities and the notation thereon of the
payment if only partially paid and upon surrender thereof if fully paid:

          FIRST:  to the payment of all amounts due the Trustee under
     Section 6.07;

          SECOND:  subject to Article XII, to the payment of the amounts then
     due and unpaid for first, interest (including Additional Interest) on,
     and, second, for principal of (and premium, if any, on) the Securities in
     respect of which or for the benefit of which such money has been
     collected, ratably, without preference or


<PAGE>

                                                                          51


     priority of any kind, according to the amounts due and payable on such
     Securities for interest and principal (and premium, if any) respectively;

          THIRD:  the balance, if any, to the Person or Persons entitled
     thereto, as their interest may appear or as a court of competent
     jurisdiction shall direct; and

          FOURTH:  to the Company.

          SECTION 5.07.  LIMITATION ON SUITS.  No Holder of any Security
shall have any right to institute any proceeding, judicial or otherwise, with
respect to this Indenture, or for the appointment of a receiver or trustee,
or for any other remedy hereunder, unless

          (1) such Holder has previously given written notice to a Responsible
     Officer the Trustee of a continuing Event of Default;

          (2) the Holders of not less than 25% in principal amount of the
     Outstanding Securities shall have made written request to the Trustee to
     institute proceedings in respect of such Event of Default in its own name
     as Trustee hereunder;

          (3) such Holder or Holders have offered to the Trustee written
     indemnity satisfactory to it (which indemnity shall not be unreasonable)
     against the costs, expenses and liabilities to be incurred in compliance
     with such request;

          (4) the Trustee for 60 days after its receipt of such notice, request
     and offer of indemnity has failed to institute any such proceeding; and

          (5) no direction inconsistent with such written request has been
     given to the Trustee during such 60-day period by the Holders of a
     majority in principal amount of the Outstanding Securities;

it being understood and intended that no one or more of such Holders shall
have any right in any manner whatever by virtue of, or by availing of, any
provision of this Indenture to affect, disturb or prejudice the fights of any
other of such Holders, or to obtain or to seek to obtain priority or
preference over any other of such Holders or to enforce any right under this
Indenture, except in the manner herein provided and for the equal and ratable
benefit of all of such Holders.

          SECTION 5.08.  UNCONDITIONAL RIGHT OF HOLDERS TO RECEIVE PRINCIPAL,


<PAGE>

                                                                          52


PREMIUM AND INTEREST AND TO CONVERT.  Notwithstanding any other provision in
this Indenture, the Holder of any Security shall have the right, which is
absolute and unconditional, to receive payment of the principal of (and
premium, if any) and (subject to Section 3.07) interest on such Security on
the respective Stated Maturities expressed in such Security (or, in the case
of redemption or purchase, on the Redemption Date or Purchase Date, as the
case may be) and to convert such Security in accordance with Article XIII and
to institute suit for the enforcement of any such payment and right to
convert, and such rights shall not be impaired without the consent of such
Holder.

          SECTION 5.09.  RESTORATION OF RIGHTS AND REMEDIES. If the Trustee
or any Holder has instituted any proceeding to enforce any right or remedy
under this Indenture and such proceeding has been discontinued or abandoned
for any reason, or has been determined adversely to the Trustee or to such
Holder, then and in every such case, subject to any determination in such
proceeding, the Company, the Trustee and the Holders shall be restored
severally and respectively to their former positions hereunder and thereafter
all rights and remedies of the Trustee and the Holders shall continue as
though no such proceeding had been instituted.

          SECTION 5.10.  RIGHTS AND REMEDIES CUMULATIVE. Except as otherwise
provided with respect to the replacement or payment of mutilated, destroyed,
lost or stolen Securities in the last paragraph of Section 3.06, no right or
remedy herein conferred upon or reserved to the Trustee or to the Holders is
intended to be exclusive of any other right or remedy, and every right and
remedy shall, to the extent permitted by law, be cumulative and in addition
to every other right and remedy given hereunder or now or hereafter existing
at law or in equity or otherwise.  The assertion or employment of any right
or remedy hereunder, or otherwise, shall not prevent the concurrent assertion
or employment of any other appropriate right or remedy.

          SECTION 5.11.  DELAY OR OMISSION NOT WAIVER.  No delay or omission
of the Trustee or of any Holder of any Securities to exercise any right or
remedy accruing upon any Event of Default shall impair any such right or
remedy or constitute a waiver of any such Event of Default or an acquiescence
therein. Every right and remedy given by this Article V or by law to the
Trustee or to the Holders may be exercised from time to time, and as often as
may be deemed expedient, by the Trustee or by the Holders, as the case may be.

          SECTION 5.12.  CONTROL BY HOLDERS.  The Holders of a majority in


<PAGE>

                                                                          53


principal amount of the Outstanding Securities shall have the right to direct
the time, method and place of conducting any proceeding for any remedy
available to the Trustee or exercising any trust or power conferred on the
Trustee; PROVIDED that the Trustee may seek the advice of counsel and

          (1) such direction shall not be in conflict with any rule of law or
     with this Indenture, and

          (2) the Trustee may take any other action deemed proper by the
     Trustee which is not inconsistent with such direction.

          SECTION 5.13.  WAIVER OF PAST DEFAULTS.  The Holders of not less
than a majority in principal amount of the Outstanding Securities may on
behalf of the Holders of all the Securities waive any past default hereunder
and its consequences, except a default

          (1) in the payment of the principal of (or premium, if any) or
     interest on any Security, or

          (2) in respect of a covenant or provision hereof which under
     Article IX cannot be modified or amended without the consent of the Holder
     of each Outstanding Security affected.

          Upon any such waiver, such default shall cease to exist, and any
Event of Default arising therefrom shall be deemed to have been cured, for
every purpose of this Indenture; but no such waiver shall extend to any
subsequent or other default or impair any right consequent thereon.  A copy
of such waiver shall be delivered by the Company to the Trustee.

          SECTION 5.14. UNDERTAKING FOR COSTS.  In any suit for the
enforcement of any right or remedy under this Indenture, or in any suit
against the Trustee for any action taken, suffered or omitted by it as
Trustee, a court may require any party litigant in such suit to file an
undertaking to pay the costs of such suit, and may assess costs against any
such party litigant, having due regard to the merits and good faith of the
claims or defenses made by such party litigant; PROVIDED, that this Section
5.14 shall not be deemed to authorize any court to require such an
undertaking or to make such an assessment in any suit instituted by the
Trustee or the Company or in any suit for the enforcement of the right to
convert any Security in accordance with Article XIII.

          SECTION 5.15.  WAIVER OF USURY, STAY OR EXTENSION LAWS.  The
Company covenants (to the extent that it may lawfully do so) that it will not
at any time


<PAGE>

                                                                          54


insist upon, or plead, or in any manner whatsoever claim or take the benefit
or advantage of, any usury, stay or extension law wherever enacted, now or at
any time hereafter in force, which may affect the covenants or the
performance of this Indenture; and the Company (to the extent that it may
lawfully do so) hereby expressly waives all benefit or advantage of any such
law and covenants that it will not hinder, delay or impede the execution of
any power herein granted to the Trustee, but will suffer and permit the
execution of every such power as though no such law had been enacted.


                                      ARTICLE VI

                                     THE TRUSTEE

          SECTION 6.01. CERTAIN DUTIES AND RESPONSIBILITIES.  (a)  Except
during the continuance of an Event of Default,

          (1) the Trustee undertakes to perform such duties and only such
     duties as are specifically set forth in this Indenture, and no implied
     covenants or obligations shall be read into this Indenture against the
     Trustee; and

          (2) in the absence of bad faith on its part, the Trustee may
     conclusively rely, as to the truth of the statements and the correctness
     of the opinions expressed therein, upon certificates or opinions furnished
     to the Trustee and conforming to the requirements of this Indenture; but
     in the case of any such certificates or opinions which by any provision
     hereof are specifically required to be furnished to the Trustee, the
     Trustee shall be under a duty to examine the same to determine whether or
     not they conform to the requirements of this Indenture (but need not
     confirm or investigate the accuracy of mathematical calculations or other
     facts stated therein).

          (b)  In case an Event of Default has occurred and is continuing,
the Trustee shall exercise such of the rights and powers vested in it by this
Indenture, and use the same degree of care and skill in their exercise, as a
prudent person would exercise or use under the circumstances in the conduct
of his or her own affairs.

          (c)  No provision of this Indenture shall be construed to relieve the
Trustee from liability for its own negligent action, its own negligent failure
to act, or its own willful misconduct, EXCEPT that

<PAGE>
                                                                            55

          (1) this paragraph (c) shall not be construed to limit the effect of
     paragraph (a) of this Section;

          (2) the Trustee shall not be liable for any error of judgment made in
     good faith by a Responsible Officer, unless it shall be proved that the
     Trustee was negligent in ascertaining the pertinent facts;

          (3) the Trustee shall not be liable with respect to any action taken
     or omitted to be taken by it in good faith in accordance with the direction
     of the Holders of a majority in principal amount of the Outstanding
     Securities relating to the time, method and place of conducting any
     proceeding for any remedy available to the Trustee, or exercising any trust
     or power conferred upon the Trustee, under this Indenture; and

          (4) no provision of this Indenture shall require the Trustee to expend
     or risk its own funds or otherwise incur any financial liability in the
     performance of any of its duties hereunder, or in the exercise of any of
     its rights or powers.

          (d)  Whether or not therein expressly so provided, every provision of
this Indenture relating to the conduct or affecting the liability of or
affording protection to the Trustee (as Trustee, Paying Agent, Authenticating
Agent or Security Registrar) shall be subject to the provisions of this Section.

          SECTION 6.02.  NOTICE OF DEFAULTS.  Within 90 days after the
occurrence of any default hereunder, the Trustee shall give the Holders, in the
manner provided in Section 1.06, notice of any default hereunder actually known
to a Responsible Officer of the Trustee; PROVIDED, HOWEVER, that in the case of
any default of the character specified in Section 5.01(3), no such notice to
Holders shall be given until at least 30 days after the occurrence thereof.  The
Trustee shall not be deemed to have notice of a default unless (i) the Trustee
has received written notice thereof from the Company or any Holder or (ii) a
Responsible Officer of the Trustee shall have actual knowledge thereof.  For the
purpose of this Section, the term "default" means any event  which is, or after
notice or lapse of time or both would become, an Event of Default.

          SECTION 6.03.  CERTAIN RIGHTS OF TRUSTEE.  Subject to the provisions
of Section 6.01:

          (a) the Trustee may conclusively rely and shall be protected in acting
     or refraining from acting upon any resolution, certificate, statement,
     instrument,

<PAGE>
                                                                            56

     opinion, report, notice, request, direction, consent, order, bond,
     debenture, note, other evidence of indebtedness or other paper or document
     believed by it to be genuine and to have been signed or presented by the
     proper party or parties;

          (b) any request or direction of the Company mentioned herein shall be
     sufficiently evidenced by a Company Request or Company Order and any
     resolution of the Board of Directors shall be sufficiently evidenced by a
     Board Resolution;

          (c) whenever in the administration of this Indenture the Trustee shall
     deem it desirable that a matter be proved or established prior to taking,
     suffering or omitting any action hereunder, the Trustee (unless other
     evidence be herein specifically prescribed) may require and, in the absence
     of bad faith on its part, conclusively rely upon an Opinion of Counsel and
     Officers' Certificate;

          (d) the Trustee may consult with counsel of its selection and the
     advice of such counsel or any Opinion of Counsel shall be full and complete
     authorization and protection in respect of any action taken, suffered or
     omitted by it hereunder in good faith and in reliance thereon;

          (e) the Trustee shall be under no obligation to exercise any of the
     rights or powers vested in it by this Indenture at the request or direction
     of any of the Holders pursuant to this Indenture, unless such Holders shall
     have offered to the Trustee security or indemnity satisfactory to the
     Trustee (which security or indemnity shall not be unreasonable) against the
     costs, expenses and liabilities which might be incurred by it in compliance
     with such request or direction;

          (f) the Trustee shall not be bound to make any investigation into the
     facts or matters stated in any resolution, certificate, statement,
     instrument, opinion, report, notice, request, direction, consent, order,
     bond, debenture, note, other evidence of indebtedness or other paper or
     document, but the Trustee, in its discretion, may make such further inquiry
     or investigation into such facts or matters as it may see fit, and, if the
     Trustee shall determine to make such further inquiry or investigation, it
     shall be entitled to examine the books, records and premises of the
     Company, personally or by agent or attorney at the Company's expense; and

          (g) the Trustee may execute any of the trusts or powers hereunder or
     perform any duties hereunder either directly or by or through agents or
     attorneys and

<PAGE>
                                                                            57

     the Trustee shall not be responsible for any misconduct or negligence on
     the part of any agent or attorney appointed with due care by it hereunder.

          (h) no provision of this Indenture shall require the Trustee to expend
     or risk its own funds or otherwise incur any financial liability in the
     performance of any of its duties hereunder, or in the exercise of any of
     its rights or powers.

          SECTION 6.04.  NOT RESPONSIBLE FOR RECITALS OR ISSUANCE OF SECURITIES.
The recitals contained herein and in the Securities, except the Trustee's
certificates of authentication, shall be taken as the statements of the Company,
and neither the Trustee nor any Authenticating Agent assumes any responsibility
for their correctness.  The Trustee makes no representations as to the validity
or sufficiency of this Indenture or of the Securities.  Neither the Trustee nor
any Authenticating Agent shall be accountable for the use or application by the
Company of Securities or the proceeds thereof.

          SECTION 6.05.  MAY HOLD SECURITIES.  The Trustee, any Authenticating
Agent, any Paying Agent, any Security Registrar or any other agent of the
Company, in its individual or any other capacity, may become the owner or
pledgee of Securities and, subject to Section 6.08 and Section 6.13, may
otherwise deal with the Company with the same rights it would have if it were
not Trustee, Authenticating Agent, Paying Agent, Security Registrar or such
other agent.

          SECTION 6.06.  MONEY HELD IN TRUST.  Money held by the Trustee in
trust hereunder need not be segregated from other funds except to the extent
required by law.  The Trustee shall be under no liability for interest on any
money received by it hereunder except as otherwise agreed with the Company in
writing.

          SECTION 6.07.  COMPENSATION AND REIMBURSEMENT.  The Company agrees:

          (1) to pay to the Trustee from time to time such compensation as shall
     be agreed in writing between the Company and the Trustee for all services
     rendered by it hereunder (which compensation shall not be limited by any
     provision of law in regard to the compensation of a trustee of an express
     trust);

          (2) except as otherwise expressly provided herein, to reimburse the
     Trustee upon its request for all reasonable expenses, disbursements and
     advances incurred or made by the Trustee in accordance with any provision
     of this Indenture (including the reasonable compensation and the expenses
     and disbursements of its agents and counsel), except any such expense,
     disbursement or advance as may be attributable to its negligence or willful
     misconduct;

<PAGE>
                                                                            58

          (3) to indemnify each of the Trustee and any predecessor Trustee for,
     and to hold each harmless against, any loss, liability or expense incurred
     without negligence or willful misconduct on its part, arising out of or in
     connection with the acceptance or administration of this trust, including
     the costs and expenses of defending itself against any claim (whether
     asserted by the Company, a Holder of Securities or any other Person) or
     liability in connection with the exercise or performance of any of its
     powers or duties hereunder.  The Trustee shall notify the Company of any
     claim asserted against it for which it may seek indemnity;

          (4)  all indemnifications and releases from liability granted
     hereunder to the Trustee shall extend to its officers, directors,
     employees, agents, successors and assigns;

          (5)  when the Trustee incurs expenses or renders services after the
     occurrence of any Event of Default specified in Section 5.01, the expenses
     and the compensation for the services are intended to constitute expenses
     of administration under any bankruptcy, insolvency or similar laws; and

          (6)  the obligations of the Company under this Section shall survive
     the satisfaction and discharge of this Indenture.

          SECTION 6.08.  DISQUALIFICATION; CONFLICTING INTERESTS.  If the
Trustee has or shall acquire a conflicting interest within the meaning of the
Trust Indenture Act, the Trustee shall either eliminate such interest or resign,
to the extent and in the manner provided by, and subject to the provisions of,
the Trust Indenture Act and this Indenture.

          SECTION 6.09.  CORPORATE TRUSTEE REQUIRED; ELIGIBILITY.  There shall
at all times be a Trustee hereunder which shall be a corporation organized and
doing business under the laws of the United States, authorized under such laws
to exercise corporate trust powers, which shall have (or, in the case of a
corporation included in a bank holding company system, the related bank holding
company shall have) a combined capital and surplus of at least U.S.$50,000,000,
subject to supervision or examination by Federal or State authority, in good
standing and having an established place of business or agency in the Borough of
Manhattan, The City of New York.  If such corporation or related bank holding
company publishes reports of condition at least annually, pursuant to law or to
the requirements of said supervising or examining authority, then for the
purposes of this Section, the combined capital and surplus of such corporation
or related bank holding company shall be deemed to be its combined capital and
surplus as set forth in its most recent report of condition so published.  If at
any time the Trustee shall cease

<PAGE>
                                                                            59

to be eligible in accordance with the provisions of this Section, it shall
resign immediately in the manner and with the effect hereinafter specified in
this Article VI.

          SECTION 6.10.  RESIGNATION AND REMOVAL; APPOINTMENT OF SUCCESSOR. (a)
No resignation or removal of the Trustee and no appointment of a successor
Trustee pursuant to this Article shall become effective until the acceptance of
appointment by the successor Trustee in accordance with the applicable
requirements of Section 6.11.

          (b)  The Trustee may resign at any time by giving written notice
thereof to the Company.  If the instrument of acceptance by a successor Trustee
required by Section 6.11 shall not have been delivered to the Trustee within
30 days after the giving of such notice of resignation, the resigning Trustee
may petition any court of competent jurisdiction for the appointment of a
successor Trustee.

          (c)  The Trustee may be removed at any time by Act of the Holders of a
majority in principal amount of the Outstanding Securities, delivered to the
Trustee and to the Company.  If the instrument of acceptance by a successor
Trustee required by Section 6.11 shall not have been delivered to the Trustee
within 30 days after the giving of such notice of removal, the removed Trustee
may petition any court of competent jurisdiction for the appointment of a
successor Trustee.

          (d)  If at any time:

          (1)  the Trustee shall fail to comply with Section 6.08 after written
     request therefor by the Company or by any Holder who has been a bona fide
     Holder of a Security for at least six months, or

          (2)  the Trustee shall cease to be eligible under Section 6.09 and
     shall fail to resign after written request therefor by the Company or by
     any such Holder, or

          (3)  the Trustee shall become incapable of acting or shall be adjudged
     a bankrupt or insolvent or a receiver of the Trustee or of its property
     shall be appointed or any public officer shall take charge or control of
     the Trustee or of its property or affairs for the purpose of
     rehabilitation, conservation or liquidation,

then, in any such case, (i) the Company by a Board Resolution may remove the
Trustee, or (ii) subject to Section 5.14, any Holder who has been a bona fide
Holder of a Security

<PAGE>
                                                                            60

for at least six months may, on behalf of himself and all others similarly
situated, petition any court of competent jurisdiction for the removal of the
Trustee and the appointment of a successor Trustee.

          (e)  If the Trustee shall resign, be removed or become incapable of
acting, or if a vacancy shall occur in the office of Trustee for any cause, the
Company, by a Board Resolution, shall promptly appoint a successor Trustee.  If,
within one year after such resignation, removal or incapability, or the
occurrence of such vacancy, a successor Trustee shall be appointed by Act of the
Holders of a majority in principal amount of the Outstanding Securities
delivered to the Company and the retiring Trustee, the successor Trustee so
appointed shall, forthwith upon its acceptance of such appointment in accordance
with the applicable requirements of Section 6.11, become the successor Trustee
and to that extent supersede the successor Trustee appointed by the Company.  If
no successor Trustee shall have been so appointed by the Company or the Holders
and accepted appointment in the manner required by Section 6.11, any Holder who
has been a bona fide Holder of a Security for at least six months may, on behalf
of himself and all others similarly situated, petition any court of competent
jurisdiction for the appointment of a successor Trustee.

          (f)  The Company shall give notice of each resignation and each
removal of the Trustee and each appointment of a successor Trustee to all
Holders in the manner provided in Section 1.06.  Each notice shall include the
name of the successor Trustee and the address of its Corporate Trust Office.

          SECTION 6.11.  ACCEPTANCE OF APPOINTMENT BY SUCCESSOR.  Every
successor Trustee appointed hereunder shall execute, acknowledge and deliver to
the Company and to the retiring Trustee an instrument accepting such
appointment, and thereupon the resignation or removal of the retiring Trustee
shall become effective and such successor Trustee, without any further act, deed
or conveyance, shall become vested with all the rights, powers, trusts and
duties of the retiring Trustee; but, on the request of the Company or the
successor Trustee, such retiring Trustee shall, upon payment of its charges,
execute and deliver an instrument transferring to such successor Trustee all the
rights, powers and trusts of the retiring Trustee and shall duly assign,
transfer and deliver to such successor Trustee all property and money held by
such retiring Trustee hereunder.  Upon request of any such successor Trustee,
the Company shall execute any and all instruments for more fully and certainly
vesting in and confirming to such successor Trustee all such rights, powers and
trusts.

          No successor Trustee shall accept its appointment unless at the time
of such acceptance such successor Trustee shall be qualified and eligible under
this

<PAGE>
                                                                            61

Article VI.

          SECTION 6.12.  MERGER, CONVERSION, CONSOLIDATION OR SUCCESSION TO
BUSINESS.  Any corporation into which the Trustee may be merged or converted or
with which it may be consolidated, or any corporation resulting from any merger,
conversion or consolidation to which the Trustee shall be a party, or any
corporation succeeding to all or substantially all the corporate trust business
of the Trustee, shall be the successor of the Trustee hereunder; PROVIDED such
corporation shall be otherwise qualified and eligible under this Article VI
without the execution or filing of any paper or any further act on the part of
any of the parties hereto.  In case any Securities shall have been
authenticated, but not delivered, by the Trustee then in office, any successor
by merger, conversion or consolidation to such authenticating Trustee may adopt
such authentication and deliver the Securities so authenticated with the same
effect as if such successor Trustee had itself authenticated such Securities.

          SECTION 6.13.  PREFERENTIAL COLLECTION OF CLAIMS AGAINST COMPANY.  If
and when the Trustee shall be or become a creditor of the Company (or any other
obligor upon the Securities), the Trustee shall be subject to the provisions of
the Trust Indenture Act regarding the collection of claims against the Company
(or any such other obligor).

          SECTION 6.14.  APPOINTMENT OF AUTHENTICATING AGENT.  The Trustee may
appoint an Authenticating Agent or Agents which shall be authorized to act on
behalf of the Trustee to authenticate Securities issued upon original issue and
upon exchange, registration of transfer, partial conversion, partial redemption,
or partial purchase or pursuant to Section 3.06, and Securities so authenticated
shall be entitled to the benefits of this Indenture and shall be valid and
obligatory for all purposes as if authenticated by the Trustee hereunder.
Wherever reference is made in this Indenture to the authentication and delivery
of Securities by the Trustee or the Trustee's certificate of authentication,
such reference shall be deemed to include authentication and delivery on behalf
of the Trustee by an Authenticating Agent and a certificate of authentication
executed on behalf of the Trustee by an Authenticating Agent.  Each
Authenticating Agent shall be acceptable to the Company and shall at all times
be a corporation organized and doing business under the laws of the United
States, authorized under such laws to act as Authenticating Agent, which shall
have (or, in the case of a corporation included in a bank holding company
system, the related bank holding company shall have) a combined capital and
surplus of not less than U.S.$50,000,000 and be subject to supervision or
examination by Federal or State authority.  If such Authenticating Agent
publishes

<PAGE>
                                                                            62

reports of condition at least annually, pursuant to law or to the
requirements of said supervising or examining authority, then, for the
purposes of this Section, the combined capital and surplus of such
Authenticating Agent or related bank holding company shall be deemed to be
its combined capital and surplus as set forth in its most recent report of
condition so published.  If at any time an Authenticating Agent shall cease
to be eligible in accordance with the provisions of this Section, such
Authenticating Agent shall resign immediately in the manner and with the
effect specified in this Section.

          Any corporation into which an Authenticating Agent may be merged or
converted or with which it may be consolidated, or any corporation resulting
from any merger, conversion or consolidation to which such Authenticating Agent
shall be a party, or any corporation succeeding to all or substantially all the
corporate agency or corporate trust business of an Authenticating Agent, shall
continue to be an Authenticating Agent; PROVIDED such corporation shall be
otherwise eligible under this Section, without the execution or filing of any
paper or any further act on the part of the Trustee or the Authenticating Agent.

          An Authenticating Agent may resign at any time by giving written
notice thereof to the Trustee and to the Company.  The Trustee may at any time
terminate the agency of an Authenticating Agent by giving written notice thereof
to such Authenticating Agent and to the Company.  Upon receiving such a notice
of resignation or upon such a termination, or in case at any time such
Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section 6.14, the Trustee may appoint a successor
Authenticating Agent which shall be acceptable to the Company and shall mail
written notice of such appointment by first-class mail, postage prepaid, to all
Holders as their names and addresses appear in the Security Register.  Any
successor Authenticating Agent upon acceptance of its appointment hereunder
shall become vested with all the rights, powers and duties of its predecessor
hereunder, with like effect as if originally named as an Authenticating Agent.
No successor Authenticating Agent shall be appointed unless eligible under the
provisions of this Section 6.14.

          The Company agrees to pay to each Authenticating Agent from time to
time compensation for its services under this Section 6.14.

          If an appointment is made pursuant to this Section, the Securities may
have endorsed thereon, in addition to the Trustee's certificate of
authentication, an alternative certificate of authentication in the following
form:

          This is one of the Securities described in the within-mentioned
Indenture.

<PAGE>
                                                                            63



Dated:                                 The Bank of New York
       ----------------           ------------------------------
                                           As Trustee


                               By
                                  ------------------------------
                                     As Authenticating Agent


                               By
                                  ------------------------------
                                      Authorized Signatory

          SECTION 6.15.  APPOINTMENT OF CO-TRUSTEE.  Subject to the
qualifications set forth in Section 6.09, the Trustee may appoint an additional
institution as a separate trustee or co-trustee. If the Trustee appoints an
additional institution as a separate trustee or co-trustee, each and every
remedy, power, fight, claim, demand, cause of action, immunity, estate, duty,
obligation, title, interest and lien expressed or intended by this Indenture to
be exercised by, vested in and conveyed by the Trustee with respect thereto
shall be exercisable by, vested in and conveyed to such separate trustee or
co-trustee, but only to the extent necessary to enable such separate trustee or
co-trustee to exercise such powers, rights and remedies, and every covenant and
obligation necessary for the exercise thereby by such separate trustee or
co-trustee shall run to and be enforceable by either of them.  Should any
instrument in writing from the Company be required by the separate trustee or
co-trustee so appointed by the Trustee for more fully vesting in and confirming
to them such properties, rights, powers, trusts, duties and obligations, any and
all such instruments in writing shall, on request, be executed, acknowledged and
delivered by the Company.  If any separate trustee or co-trustee, or a successor
to either, shall become incapable of acting or not qualified to act, resign or
be removed, all the estate, properties, rights, powers, trusts, duties and
obligations of such separate trustee or co-trustee, so far as permitted by law,
shall vest in and be exercised by the Trustee until the appointment of a
successor to such separate trustee or co-trustee.  The appointment of any
separate trustee or co-trustee shall be subject to written approval of the
Company so long as no Event of Default has occurred and is continuing under this
Indenture.


                                     ARTICLE VII

                  HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY

<PAGE>
                                                                            64

          SECTION 7.01.  COMPANY TO FURNISH TRUSTEE NAMES AND ADDRESSES OF
HOLDERS.  The Company will furnish or cause to be furnished to the Trustee

          (a) semi-annually, not more than 15 days after each Regular Record
     Date, a list, in such form as the Trustee may reasonably require, of the
     names and addresses of the Holders as of such Regular Record Date, and

          (b) at such other times as the Trustee may request in writing, within
     30 days after the receipt by the Company of any such request, a list of
     similar form and content as of a date not more than 15 days prior to the
     time such list is furnished;

EXCLUDING from any such list names and addresses received by the Trustee in its
capacity as Security Registrar.

          SECTION 7.02.  PRESERVATION OF INFORMATION; COMMUNICATIONS TO HOLDERS.
(a)  The Trustee shall preserve, in as current a form as is reasonably
practicable, the names and addresses of Holders contained in the most recent
list furnished to the Trustee as provided in Section 7.01 and the names and
addresses of Holders received by the Trustee in its capacity as Security
Registrar.  The Trustee may destroy any list furnished to it as provided in
Section 7.01 upon receipt of a new list so furnished.

          (b)  The rights of Holders to communicate with other Holders with
respect to their rights under this Indenture or under the Securities, and the
corresponding rights and duties of the Trustee, shall be as provided by the
Trust Indenture Act.

          (c)  Every Holder of Securities, by receiving and holding the same,
agrees with the Company and the Trustee that neither the Company nor the Trustee
nor any agent of either of them shall be held accountable by reason of any
disclosure of information as to names and addresses of Holders made pursuant to
the Trust Indenture Act.

          SECTION 7.03.  REPORTS BY TRUSTEE.  (a)  The Trustee shall transmit to
Holders within 60 days after May 15th of each year such reports concerning the
Trustee and its actions under this Indenture as may be required pursuant to the
Trust Indenture Act at the times and in the manner provided pursuant thereto.


<PAGE>
                                                                            65

          (b)  A copy of each such report shall, at the time of such
transmission to Holders, be filed by the Trustee with each stock exchange upon
which the Securities are listed, with the Commission, if applicable, and with
the Company.  The Company will promptly notify the Trustee when the Securities
are listed on any stock exchange and of any delisting thereof.

          SECTION 7.04.  REPORTS BY COMPANY.  (a)  The Company shall file with
the Trustee and the Commission, if applicable, and transmit to Holders, such
information, documents and other reports, and such summaries thereof, as may be
required pursuant to the Trust Indenture Act at the times and in the manner
provided pursuant to such Act; PROVIDED that any such information, documents or
reports required to be filed with the Commission pursuant to Section 13 or 15(d)
of the Exchange Act shall be filed with the Trustee within 15 days after the
same is so required to be filed with the Commission.  Delivery of such reports,
information and documents to the Trustee is for informational purposes only, and
the Trustee's receipt of such shall not constitute constructive notice of any
information contained therein or determinable from information contained
therein, including the Company's compliance with any of its covenants hereunder
(as to which the Trustee is entitled to rely exclusively on Officers'
Certificates).  Notwithstanding anything to the contrary contained herein, the
Trustee shall have no duty to review such documents for the purpose of
determining compliance with this Indenture.

     Delivery of such reports, information and documents to the Trustee is for
informational purposes only and the Trustee's receipt of such shall not
constitute constructive notice of any information contained therein or
determinable from information contained therein, including the Company's
compliance with any of its covenants hereunder (as to which the Trustee is
entitled to rely exclusively on Officers' Certificates).

          (b)  The Company shall provide the Trustee with at least 30 days'
prior written notice of any change in location of its principal executive
offices or other principal place of business.


                                     ARTICLE VIII

                 CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

          SECTION 8.01.  COMPANY MAY CONSOLIDATE, ETC., ONLY ON CERTAIN TERMS.
The Company shall not consolidate with or merge into any other Person or,
directly or indirectly, convey, transfer, sell, lease or otherwise dispose of
all or substantially all of its

<PAGE>
                                                                            66

properties and assets to any Person, and the Company shall not permit any
Person to consolidate with or merge into the Company or convey, transfer,
sell, lease or otherwise dispose of all or substantially all of its
properties and assets to the Company, unless:

          (1) in case the Company shall consolidate with or merge into another
     Person or convey, transfer or lease its properties and assets substantially
     as an entirety to any Person, the Person formed by such consolidation or
     into which the Company is merged or the Person which acquires by conveyance
     or transfer, or which leases, the properties and assets of the Company
     substantially as an entirety (i) shall be a corporation, partnership or
     trust, (ii)  shall be an entity (A) organized and validly existing under
     the laws of the United States of America, any State thereof or the District
     of Columbia or (B) organized and validly existing under the laws of a
     jurisdiction outside of the United States of America, with its common
     stock, or American Depositary Shares representing such shares of common
     stock, traded on a national securities exchange in the United States of
     America or through Nasdaq and a worldwide total market capitalization of
     its equity securities of at least U.S. $5 billion, and (iii) shall
     expressly assume, by an indenture supplemental hereto, executed and
     delivered to the Trustee, in form satisfactory to the Trustee, the due and
     punctual payment of the principal of (and premium, if any) and interest
     (including Additional Interest) on all the Securities and the performance
     or observance of every covenant of this Indenture on the part of the
     Company to be performed or observed and shall have provided for conversion
     rights in accordance with Article XIII;

          (2) immediately after giving effect to such transaction, no Event of
     Default, and no event which, after notice or lapse of time or both, would
     become an Event of Default, shall have happened and be continuing; and

          (3) the Company has delivered to the Trustee an Officers' Certificate
     and an Opinion of Counsel, each stating that such consolidation, merger,
     conveyance, transfer or lease and, if a supplemental indenture is required
     in connection with such transaction, such supplemental indenture comply
     with this Article VIII and that all conditions precedent herein provided
     for relating to such transaction have been complied with.

          SECTION 8.02.  SUCCESSOR SUBSTITUTED.  Upon any consolidation of the
Company with, or merger of the Company into, any other Person or any conveyance,

<PAGE>
                                                                            67

transfer or lease of the properties and assets of the Company substantially as
an entirety in accordance with Section 8.01, the successor Person formed by such
consolidation or into which the Company is merged or to which such conveyance,
transfer or lease is made shall succeed to, and be substituted for, and may
exercise every right and power of, the Company under this Indenture with the
same effect as if such successor Person had been named as the Company herein,
and thereafter, except in the case of a lease, the predecessor Person shall be
released from its obligations and covenants under this Indenture and the
Securities.


                                      ARTICLE IX

                               SUPPLEMENTAL INDENTURES

          SECTION 9.01.  SUPPLEMENTAL INDENTURES WITHOUT CONSENT OF HOLDERS.
Without the consent of any Holders, the Company, when authorized by a Board
Resolution, and the Trustee, at any time and from time to time, may enter into
one or more indentures supplemental hereto, in form satisfactory to the Trustee,
for any of the following purposes:

          (1) to evidence the succession of another Person to the Company and
     the assumption by any such successor of the covenants of the Company herein
     and in the Securities; or

          (2) to add to the covenants of the Company for the equal and ratable
     benefit of the Holders, or to surrender any right or power herein conferred
     upon the Company; or

          (3) to secure the Company's obligations in respect of the Securities;
     or

          (4) to make provision with respect to the conversion rights of Holders
     pursuant to the requirements of Article XIII; or

          (5) to make any changes or modifications to this Indenture necessary
     in connection with the registration of any Transfer Restricted Securities
     under the Securities Act as contemplated by Section 10.11; PROVIDED that
     such action pursuant to this clause (5) shall not adversely affect the
     interests of the Holders of Securities; or

          (6) to cure any ambiguity, to correct or supplement any provision
     herein

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                                                                            68

     which may be inconsistent with any other provision herein, to correct or
     supplement any provision herein which limits, qualifies or conflicts with
     a provision of the Trust Indenture Act which is required under such Act
     to be a part of and govern this Indenture, in any case to the extent
     necessary to qualify this Indenture under the Trust Indenture Act, or
     to make any other provisions with respect to matters or questions arising
     under this Indenture which shall not be inconsistent with the provisions
     of this Indenture; PROVIDED that such action pursuant to this clause (6)
     shall not adversely affect the interests or legal rights of the Holders
     in any material respect.

          SECTION 9.02.  SUPPLEMENTAL INDENTURES WITH CONSENT OF HOLDERS.  With
the consent of the Holders of not less than a majority in principal amount of
the Outstanding Securities, by the Act of said Holders delivered to the Company
and the Trustee, the Company, when authorized by a Board Resolution, and the
Trustee may enter into an indenture or indentures supplemental hereto for the
purpose of adding any provisions to or changing in any manner or eliminating any
of the provisions of this Indenture or of modifying in any manner the rights of
the Holders under this Indenture; PROVIDED, HOWEVER, that no such supplemental
indenture shall, without the consent of the Holder of each Outstanding Security
affected thereby,

          (1) change the Stated Maturity of the principal of, or any installment
     of interest on, any Security, or reduce the principal amount thereof or the
     rate of interest thereon or any premium payable upon the redemption
     thereof, or change the place of payment where, or the coin or currency in
     which, any Security or any premium or interest thereon is payable, or
     impair the right to institute suit for the enforcement of any such payment
     on or after the Stated Maturity thereof (or, in the case of redemption or
     purchase, on or after the Redemption Date or Purchase Date, as the case may
     be), or adversely affect the right to convert any Security as provided in
     Article XIII (except as permitted by Section 9.01(4)), or modify the
     provisions of this Indenture with respect to the subordination of the
     Securities in a manner adverse to the Holders, or modify the redemption
     provisions in a manner adverse to the Holders, or modify the provisions
     relating to the Company's requirement to offer to purchase Notes upon a
     Change in Control in a manner adverse to the Holders, or

          (2) modify any of the provisions of this Section 9.02, Section 5.13 or
     Section 10.08, except to increase any such percentage or to provide that
     certain other provisions of this Indenture cannot be modified or waived
     without the consent of the

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                                                                            69

     Holder of each Outstanding Security affected thereby, or

          (3) modify the obligation of the Company to maintain an office or
     agency in the Borough of Manhattan, The City of New York  pursuant to
     Section 10.02, or

          (4) modify any of the provisions of Section 10.09 or Section 10.10, or

          (5) reduce the percentage in principal amount of the Outstanding
     Securities, the consent of whose Holders is required for any such
     supplemental indenture, or the consent of whose Holders is required for any
     waiver (of compliance with certain provisions of this Indenture or certain
     defaults hereunder and their consequences) provided for in this Indenture.

          It shall not be necessary for any Act of Holders under this
Section 9.02 to approve the particular form of any proposed supplemental
indenture, but it shall be sufficient if such Act shall approve the substance
thereof.

          SECTION 9.03.  EXECUTION OF SUPPLEMENTAL INDENTURES.  In executing,
or accepting the additional trusts created by, any supplemental indenture
permitted by this Article IX or the modifications thereby of the trusts
created by this Indenture, the Trustee shall receive, and (subject to Section
6.01 and Section 6.03) shall be fully protected in relying upon, an Opinion
of Counsel stating that the execution of such supplemental indenture is
authorized or permitted by this Indenture, complies with its terms and will,
upon the execution and delivery thereof, be valid and binding upon the
Company in accordance with its terms.  The Trustee may, but shall not be
obligated to, enter into any such supplemental indenture which affects the
Trustee's own rights, duties or immunities under this Indenture or otherwise.

          SECTION 9.04. EFFECT OF SUPPLEMENTAL INDENTURES. Upon the execution of
any supplemental indenture under this Article, this Indenture shall be modified
in accordance therewith, and such supplemental indenture shall form a part of
this Indenture for all purposes; and every Holder of Securities theretofore or
thereafter authenticated and delivered hereunder shall be bound thereby.

          SECTION 9.05. CONFORMITY WITH TRUST INDENTURE ACT.  Every supplemental
indenture executed pursuant to this Article shall conform to the requirements of
the Trust Indenture Act.

          SECTION 9.06.  REFERENCE IN SECURITIES TO SUPPLEMENTAL INDENTURES.
Securities authenticated and delivered after the execution of any supplemental
indenture pursuant to this Article may, and shall if required by the Trustee,
bear a notation as to any

<PAGE>
                                                                            70

matter provided for in such supplemental indenture. If the Company shall so
determine, new Securities so modified as to conform, in the judgment of the
Company, to any such supplemental indenture may be prepared and executed by
the Company and authenticated and delivered by the Trustee in exchange for
Outstanding Securities.

                                      ARTICLE X

                                      COVENANTS

          SECTION 10.01.  PAYMENT OF PRINCIPAL, PREMIUM AND INTEREST.  The
Company will duly and punctually pay the principal of (and premium, if any) and
interest on the Securities in accordance with the terms of the Securities and
this Indenture.

          SECTION 10.02.  MAINTENANCE OF OFFICE OR AGENCY.  The Company will
maintain in the Borough of Manhattan, The City of New York  an office or agency
where Securities may be presented or surrendered for payment, where Securities
may be surrendered for registration of transfer or exchange, where Securities
may be surrendered for conversion and where notices and demands to or upon the
Company in respect of the Securities and this Indenture may be served.  The
Company will give prompt written notice to the Trustee of the location, and any
change in the location, of such office or agency.  If at any time the Company
shall fail to maintain any such required office or agency or shall fail to
furnish the Trustee with the address thereof, such presentations, surrenders,
notices and demands may be made or served at the Corporate Trust Office of the
Trustee or the office or agency of the Trustee in the Borough of Manhattan, The
City of New York, and the Company hereby appoints the Trustee as its agent to
receive all such presentations, surrenders, notices and demands.

          The Company may also from time to time designate one or more other
offices or agencies (in or outside the Borough of Manhattan, The City of New
York) where the Securities may be presented or surrendered for any or all such
purposes and may from time to time rescind such designations; PROVIDED, HOWEVER,
that no such designation or rescission shall in any manner relieve the Company
of its obligation to maintain an office or agency in the Borough of Manhattan,
The City of New York for such purposes.  The Company will give prompt written
notice to the Trustee of any such designation or rescission and of any change in
the location of any such other office or agency.

<PAGE>
                                                                            71

          SECTION 10.03.  MONEY FOR SECURITY PAYMENTS TO BE HELD IN TRUST.  If
the Company shall at any time act as its own Paying Agent, it will, prior to
11:00 a.m., New York City time, on each due date of the principal of (and
premium, if any) or interest (together with any Additional Interest in respect
thereof) on any of the Securities, segregate and hold in trust for the benefit
of the Persons entitled thereto a sum sufficient to pay the principal (and
premium, if any) or interest (together with any Additional Interest in respect
thereof) so becoming due until such sums shall be paid to such Persons or
otherwise disposed of as herein provided and will promptly notify the Trustee of
its action or failure so to act.

          Whenever the Company shall have one or more Paying Agents, it will,
prior to each due date of the principal of (and premium, if any) or interest
(together with any Additional Interest in respect thereof) on any Securities,
deposit with a Paying Agent a sum sufficient to pay such amount, such sum to be
held in trust for the benefit of the Persons entitled to such principal,
premium, if any, or interest, and (unless such Paying Agent is the Trustee) the
Company will promptly notify the Trustee in writing of its action or failure so
to act.

          The Company will cause each Paying Agent other than the Trustee to
execute and deliver to the Trustee an instrument in which such Paying Agent
shall agree with the Trustee, subject to the provisions of this Section 10.03,
that such Paying Agent will:

          (1) hold all sums held by it for the payment of the principal of,
     premium, if any, or interest on Securities in trust for the benefit of the
     Persons entitled thereto until such sums shall be paid to such Persons or
     otherwise disposed of as herein provided;

          (2) give the Trustee written notice of any default by the Company (or
     any other obligor upon the Securities) in the making of any payment of
     principal, premium, if any, or interest; and

          (3) at any time during the continuance of any such default, upon the
     written request of the Trustee, forthwith pay to the Trustee all sums so
     held in trust by such Paying Agent.

          The Company may at any time, for the purpose of obtaining the
satisfaction and discharge of this Indenture or for any other purpose, pay, or
by Company Order direct any Paying Agent to pay, to the Trustee all sums held in
trust by the Company or such Paying Agent, such sums to be held by the Trustee
upon the same trusts

<PAGE>
                                                                            72

as those upon which such sums were held by the Company or such Paying Agent;
and, upon such payment by any Paying Agent to the Trustee, such Paying Agent
shall be released from all further liability with respect to such money.

          Any money deposited with the Trustee or any Paying Agent, or then held
by the Company, in trust for the payment of the principal of (and premium, if
any) or interest (together with any Additional Interest in respect thereof) on
any Security and remaining unclaimed for two years after such principal (and
premium, if any) or interest has become due and payable shall be paid to the
Company on Company Request, or (if then held by the Company) shall be discharged
from such trust; and the Holder of such Security shall thereafter, as an
unsecured general creditor, look only to the Company for payment thereof, and
all liability of the Trustee or such Paying Agent with respect to such trust
money, and all liability of the Company as trustee thereof, shall thereupon
cease; PROVIDED, HOWEVER, that the Trustee or such Paying Agent, before being
required to make any such repayment, may at the expense of the Company cause to
be published once, in a newspaper published in the English language, customarily
published on each Business Day and of general circulation in the Borough of
Manhattan, The City of New York, notice that such money remains unclaimed and
that, after a date specified therein, which shall not be less than 30 days from
the date of such publication, any unclaimed balance of such money then remaining
will be repaid to the Company.

          SECTION 10.04.  STATEMENT BY OFFICERS AS TO DEFAULT.  The Company
shall deliver to the Trustee, within 120 days after the end of each fiscal year
of the Company ending after the date hereof, an Officers' Certificate, stating
whether or not to the best knowledge of the signers thereof the Company is in
default in the performance and observance of any of the terms, provisions and
conditions of this Indenture (without regard to any period of grace or
requirement of notice provided hereunder) and, if the Company shall be in
default, specifying all such defaults and the nature and status thereof of which
they may have knowledge.

          SECTION 10.05.  EXISTENCE.  Subject to Article VIII, the Company shall
do or cause to be done all things necessary to preserve and keep in full force
and effect its existence, rights (charter and statutory) and franchises;
PROVIDED, HOWEVER, that the Company shall not be required to preserve any such
right or franchise if the Board of Directors shall determine that the
preservation thereof is no longer desirable in the conduct of the business of
the Company and that the loss thereof is not disadvantageous in any material
respect to the Holders.

          SECTION 10.06.  MAINTENANCE OF PROPERTIES.  The Company shall cause
all properties used or useful in the conduct of its business or the business of
any

<PAGE>
                                                                            73

Subsidiary to be maintained and kept in good condition, repair and working
order and supplied with all necessary equipment and shall cause to be made all
necessary repairs, renewals, replacements, betterments and improvements thereof,
all as in the judgment of the Company may be necessary so that the business
carried on in connection therewith may be properly and advantageously conducted
at all times; PROVIDED, HOWEVER, that nothing in this Section 10.06 shall
prevent the Company from discontinuing the operation or maintenance of any of
such properties, or disposing of any of them, if such discontinuance or
disposition is, in the judgment of the Company, desirable in the conduct of its
business or the business of any Subsidiary and not disadvantageous in any
material respect to the Holders.

          SECTION 10.07.  PAYMENT OF TAXES AND OTHER CLAIMS.  The Company shall
pay or discharge or cause to be paid or discharged, before the same shall become
delinquent, (1) all taxes, assessments and governmental charges levied or
imposed upon the Company or any Subsidiary or upon the income, profits or
property of the Company or any Subsidiary, and (2) all lawful claims for labor,
materials and supplies which, if unpaid, might by law become a lien upon the
property of the Company or any Subsidiary; PROVIDED, HOWEVER, that the Company
shall not be required to pay or discharge or cause to be paid or discharged any
such tax, assessment, charge or claim whose amount, applicability or validity is
being contested in good faith by appropriate proceedings.

          SECTION 10.08.  WAIVER OF CERTAIN COVENANTS.  The Company may omit in
any particular instance to comply with any covenant or condition set forth in
Sections 10.05 to 10.07, inclusive, if before the time for such compliance the
Holders of at least a majority in principal amount of the Outstanding Securities
shall, by Act of such Holders, either waive such compliance in such instance or
generally waive compliance with such covenant or condition, but no such waiver
shall extend to or affect such covenant or condition except to the extent so
expressly waived, and, until such waiver shall become effective, the obligations
of the Company and the duties of the Trustee in respect of any such covenant or
condition shall remain in full force and effect.

          SECTION 10.09.  DELIVERY OF CERTAIN INFORMATION.  At any time when the
Company is not subject to Section 13 or 15(d) of the Exchange Act, upon the
request of a Holder or the holder of shares of Common Stock issued upon
conversion thereof, the Company shall promptly furnish or cause to be furnished
Rule 144A Information (as defined below) to such Holder or such holder of shares
of Common Stock issued upon conversion of Securities, or to a prospective
purchaser of any such security designated by

<PAGE>
                                                                            74

any such Holder or holder, as the case may be, to the extent required to
permit compliance by such Holder or holder with Rule 144A under the
Securities Act in connection with the resale of any such security.  "Rule
144A Information" shall be such information as is specified pursuant to Rule
144A(d)(4) under the Securities Act.

          SECTION 10.10.  RESALE OF CERTAIN SECURITIES; REPORTING ISSUER.
During the period beginning on the last date of original issuance of the
Securities and ending on the date that is two years from such date, the Company
will not, and will use its best efforts not to permit any of its "affiliates"
(as defined under Rule 144 under the Securities Act or any successor provision
thereto) to, resell (x) any Securities which constitute "restricted securities"
under Rule 144 or (y) any securities into which the Securities have been
converted under this Indenture which constitute "restricted securities" under
Rule 144, that in either case have been reacquired by any of them.  The Trustee
shall have no responsibility in respect of the Company's performance of its
agreement in the preceding sentence.

          SECTION 10.11.  REGISTRATION RIGHTS.  (a)  The Company agrees that the
Holders (and any Person that has a beneficial interest in a Security) from time
to time of Transfer Restricted Securities are entitled to the benefits of a
Registration Rights Agreement, dated as of September  22, 1999 (the
"Registration Rights Agreement"), executed by the Company.  Pursuant to the
Registration Rights Agreement, the Company has agreed for the benefit of the
Holders from time to time of Transfer Restricted Securities, at the Company's
expense, (i) to file within 90 days after the first date of original issuance of
the Securities, a shelf registration statement (the "Shelf Registration
Statement") with the Commission with respect to resales of the Transfer
Restricted Securities, (ii) to use its commercially reasonable best efforts to
cause such Shelf Registration Statement to be declared effective by the
Commission not later than 150 days after the first date of original issuance of
the Securities, and (iii) to use its commercially reasonable best efforts to
maintain such Shelf Registration Statement continuously effective under the
Securities Act subject to and in accordance with the terms of the Registration
Rights Agreement.

          Additional interest (the "Additional Interest") with respect to the
Securities shall be assessed as follows if any of the following events occur
(each such event in clauses (i) through (iii) below being herein called a
"Registration Default"):

          (i) if on or prior to the 90th day after the first date of original
     issuance of the Securities the Shelf Registration Statement has not been
     filed with the Commission;

<PAGE>
                                                                            75

          (ii) if on or prior to the 150th day after the first date of original
     issuance of the Securities the Shelf Registration Statement has not been
     declared effective by the Commission; or

          (iii) if after the Shelf Registration Statement is declared effective
     (A) the Shelf Registration Statement thereafter ceases to be effective; or
     (B) the Shelf Registration Statement or the related prospectus ceases to be
     usable subject to certain exceptions set forth in the Registration Rights
     Agreement, including the right to suspend the use of the Shelf Registration
     Statement under certain circumstances for up to 90 days) in connection with
     resales of Transfer Restricted Securities in accordance with and during the
     periods specified herein because either (1) any event occurs as a result of
     which the related prospectus forming part of such Shelf Registration
     Statement would include any untrue statement of a material fact or omit to
     state any material fact necessary to make the statements therein in the
     light of the circumstances under which they were made not misleading, or
     (2) it shall be necessary to amend such Shelf Registration Statement or
     supplement the related prospectus, to comply with the Securities Act or the
     Exchange Act or the respective rules thereunder.

          Additional Interest shall accrue on the Securities over and above the
interest set forth in the title of the Securities from and including the date on
which any such Registration Default shall occur, to but excluding the date on
which all such Registration Defaults have been cured, at a rate of 0.50% per
annum.  Written notice of any such Registration Default shall be provided to the
Trustee by the Company.

          (b)  Any amounts of Additional Interest due pursuant to clause (a)(i),
(a)(ii) or (a)(iii) of this Section 10.11 shall be payable in cash on the
regular Interest Payment Dates in the manner provided for by the Indenture.  The
amount of Additional Interest shall be determined by multiplying the applicable
Additional Interest rate by the principal amount of the Securities, multiplied
by a fraction, the numerator of which is the number of days such Additional
Interest rate was applicable during such period (determined on the basis of a
360-day year comprised of twelve 30-day months), and the denominator of which is
360.

          Whenever in this Indenture there is mentioned, in any context, the
payment of the principal of, premium, if any, or interest on, or in respect of,
any Security, such mention shall be deemed to include mention of the payment of
Additional Interest provided for in this Section to the extent that, in such
context, Additional Interest are,

<PAGE>
                                                                            76

were or would be payable in respect thereof pursuant to the provisions of
this Section 10.11 and express mention of the payment of Additional Interest
(if applicable) in any provisions hereof shall not be construed as excluding
Additional Interest in those provisions hereof where such express mention is
not made.

                                      ARTICLE XI

                               REDEMPTION OF SECURITIES

          SECTION 11.01.  RIGHT OF REDEMPTION.  The Securities may be redeemed
at the election of the Company, as a whole or from time to time in part, at any
time on or after October 7, 2002, at the Redemption Prices specified in the form
of Security hereinbefore set forth, together with accrued interest to the
Redemption Date.

          SECTION 11.02.  APPLICABILITY OF ARTICLE.  Redemption of Securities at
the election of the Company or otherwise, as permitted or required by any
provision of this Indenture, shall be made in accordance with such provision and
this Article XI.

          SECTION 11.03.  ELECTION TO REDEEM; NOTICE TO TRUSTEE.  The election
of the Company to redeem any Securities pursuant to Section 11.01 shall be
evidenced by a Board Resolution.  In case of any redemption at the election of
the Company, the Company shall, at least 45 days prior to the Redemption Date
fixed by the Company (unless a shorter notice shall be satisfactory to the
Trustee), notify the Trustee of such Redemption Date in writing and of the
principal amount of Securities to be redeemed.

          SECTION 11.04.  SELECTION BY TRUSTEE OF SECURITIES TO BE REDEEMED.  If
less than all the Securities are to be redeemed, the particular Securities to be
redeemed shall be selected not less than 30 days or more than 60 days prior to
the Redemption Date by the Trustee, from the Outstanding Securities not
previously called for redemption, by lot or by such method as the Trustee shall
deem fair and appropriate in the circumstances and which may provide for the
selection for redemption of portions (equal to U.S.$1,000 or any integral
multiple thereof) of the principal amount of Securities of a denomination larger
than U.S.$1,000.

          If any Security selected for partial redemption is converted in part
before termination of the conversion right with respect to the portion of the
Security so selected, the converted portion of such Security shall be deemed (so
far as may be) to be the portion selected for redemption.  Securities which have
been converted during a selection of Securities to be redeemed shall be treated
by the Trustee as Outstanding for the

<PAGE>
                                                                            77

purpose of such selection.

          The Trustee shall promptly notify the Company and each Security
Registrar in writing of the Securities selected for redemption and, in the case
of any Securities selected for partial redemption, the principal amount thereof
to be redeemed.

          For all purposes of this Indenture, unless the context otherwise
requires, all provisions relating to the redemption of Securities shall relate,
in the case of any Securities redeemed or to be redeemed only in part, to the
portion of the principal amount of such Securities which has been or is to be
redeemed.

          SECTION 11.05.  NOTICE OF REDEMPTION.  Notice of redemption shall be
given by first-class mail, postage prepaid, mailed not less than 30 nor more
than 60 days prior to the Redemption Date, to each Holder of Securities to be
redeemed, at his address appearing in the Security Register.

          All notices of redemption shall describe the Securities, including
CUSIP number, and state:

          (1)  the Redemption Date;

          (2)  the Redemption Price;

          (3)  if less than all the Outstanding Securities are to be redeemed,
     the identification (and, in the case of partial redemption of any
     Securities, the principal amounts) of the particular Securities to be
     redeemed;

          (4)  that on the Redemption Date the Redemption Price shall become due
     and payable upon each such Security to be redeemed and that interest
     thereon shall cease to accrue on and after said date;

          (5)  the conversion price, the date on which the right to convert the
     Securities to be redeemed will terminate and the place or places where such
     Securities may be surrendered for conversion; and

          (6)  the place or places where such Securities are to be surrendered
     for payment of the Redemption Price.

          Notice of redemption of Securities to be redeemed at the election of
the Company shall be given by the Company or, at the Company's request, by the
Trustee in

<PAGE>
                                                                            78

the name and at the expense of the Company, and shall be irrevocable.

          SECTION 11.06.  DEPOSIT OF REDEMPTION PRICE.  Prior to 11:00 a.m.,
New York City time, on any Redemption Date, the Company shall deposit with the
Trustee or with a Paying Agent (or, if the Company is acting as its own Paying
Agent, segregate and hold in trust as provided in Section 10.03) an amount of
money sufficient to pay the Redemption Price of, and (except if the Redemption
Date shall be an Interest Payment Date) accrued interest on, all the Securities
which are to be redeemed on that date other than any Securities called for
redemption on that date which have been converted prior to the date of such
deposit.

          If any Security called for redemption is converted, any money
deposited with the Trustee or with any Paying Agent or so segregated and held in
trust for the redemption of such Security shall (subject to any right of the
Holder of such Security or any Predecessor Security to receive interest as
provided in the last paragraph of Section 3.07) be paid to the Company as soon
as practicable upon Company Request or, if then held by the Company, shall be
released from such trust.

          SECTION 11.07.  SECURITIES PAYABLE ON REDEMPTION DATE.  Notice of
redemption having been given as aforesaid, the Securities so to be redeemed
shall, on the Redemption Date, become due and payable at the Redemption Price
therein specified, and from and after such date (unless the Company shall
default in the payment of the Redemption Price and accrued interest) such
Securities shall cease to bear or accrue any interest.  Upon surrender of any
such Security for redemption in accordance with said notice, such Security shall
be paid by the Company at the Redemption Price, together with accrued interest
to (but not including) the Redemption Date; PROVIDED, HOWEVER, that installments
of interest whose Stated Maturity is on or prior to the Redemption Date shall be
payable to the Holders of such Securities, or one or more Predecessor
Securities, registered as such at the close of business on the relevant Record
Dates according to their terms and the provisions of Section 3.07.

          If the Company shall fail to deposit the Redemption Price with the
Trustee and any Security called for redemption shall not be so paid upon
surrender thereof for redemption, the principal (and premium, if any) shall,
until paid, bear and accrue interest from the Redemption Date at the rate borne
by the Security.

          SECTION 11.08.  SECURITIES REDEEMED IN PART.  Any Security which is to

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                                                                            79

be redeemed only in part shall be surrendered at an office or agency of the
Company designated for that purpose pursuant to Section 10.02 (with, if the
Company or the Trustee so requires, due endorsement by, or a written instrument
of transfer in form satisfactory to the Company and the Trustee duly executed
by, the Holder thereof or his attorney-in-fact duly authorized in writing), and
the Company shall execute, and the Trustee shall authenticate and deliver to the
Holder of such Security without service charge, a new Security or Securities, of
any authorized denomination as requested by such Holder, in aggregate principal
amount equal to and in exchange for the unredeemed portion of the principal
amount of the Security so surrendered.

          SECTION 11.09.  CONVERSION ARRANGEMENT ON CALL FOR REDEMPTION.  In
connection with any redemption of Securities, the Company may arrange for the
purchase and conversion of any Securities by an agreement with one or more
investment bankers or other purchasers to purchase such Securities by paying to
the Trustee in trust for the Holders, on or before the Redemption Date, an
amount not less than the applicable Redemption Price, together with interest
accrued to the Redemption Date, of such Securities.  Notwithstanding anything to
the contrary contained in this Article XI, the obligation of the Company to pay
the Redemption Price of such Securities, together with interest accrued to, but
excluding, the Redemption Date, shall be deemed to be satisfied and discharged
to the extent such amount is so paid by such purchasers.  If such an agreement
is entered into, a copy of which shall be filed with the Trustee prior to the
Redemption Date, any Securities not duly surrendered for conversion by the
holders thereof may, at the option of the Company, be deemed, to the fullest
extent permitted by law, acquired by such purchasers from such holders and
(notwithstanding anything to the contrary contained in Article XIII) surrendered
by such purchasers for conversion, all as of immediately prior to the close of
business on the Redemption Date (and the right to convert any such Securities
shall be deemed to have been extended through such time), subject to payment of
the above amount as aforesaid.  At the written direction of the Company, the
Trustee shall hold and dispose of any such amount paid to it in the same manner
as it would monies deposited with it by the Company for the redemption of
Securities.  Without the Trustee's prior written consent, no arrangement between
the Company and such purchasers for the purchase and conversion of any
Securities shall increase or otherwise affect any of the powers, duties,
responsibilities or obligations of the Trustee as set forth in this Indenture,
and the Company agrees to indemnify the Trustee from, and hold it harmless
against, any loss, liability or expense arising out of or in connection with any
such arrangement for the purchase and conversion of any Securities between the
Company and such purchasers to which the Trustee has not consented in writing,
including the costs and expenses incurred by the Trustee in the defense of any
claim or liability arising out of or in connection with the exercise or
performance of any of its powers, duties, responsibilities or obligations under
this

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                                                                            80

Indenture.  Nothing in the preceding sentence shall be deemed to limit the
rights and protections afforded to the Trustee in Article VI hereof, including,
but not limited to, the right to indemnification pursuant to Section 6.07.


                                     ARTICLE XII

                             SUBORDINATION OF SECURITIES

          SECTION 12.01.  SECURITIES SUBORDINATE TO SENIOR INDEBTEDNESS.  The
Company covenants and agrees, and each Holder of a Security, by his acceptance
thereof, likewise covenants and agrees, that, to the extent and in the manner
hereinafter set forth in this Article XII, the indebtedness represented by the
Securities and the payment of the principal of (and premium, if any) and
interest on each and all of the Securities and all obligations of the Company
under this Indenture are hereby expressly made subordinate and subject in right
of payment to the prior payment in full of all Senior Indebtedness.

          SECTION 12.02.  PAYMENT OVER OF PROCEEDS UPON DISSOLUTION, ETC.  In
the event of (a) any insolvency or bankruptcy case or proceeding, or any
receivership, liquidation, reorganization or other similar case or proceeding in
connection therewith, relative to the Company or to its creditors, as such, or
to its assets, or (b) any liquidation, dissolution or other winding-up of the
Company, whether voluntary or involuntary and whether or not involving
insolvency or bankruptcy, or (c) any assignment for the benefit of creditors or
any other marshalling of assets and liabilities of the Company, then and in any
such event the holders of Senior Indebtedness shall be entitled to receive
payment in full of all amounts due or to become due on or in respect of all
Senior Indebtedness, or provision shall be made for such payment in cash or cash
equivalents or otherwise in a manner satisfactory to the holders of Senior
Indebtedness, before the Holders of the Securities are entitled to receive any
payment on account of principal of (or premium, if any) or interest on the
Securities, and to that end the holders of Senior Indebtedness shall be entitled
to receive, for application to the payment thereof, any payment or distribution
of any kind or character, whether in cash, property or securities, which may be
payable or deliverable in respect of the Securities in any such case,
proceeding, dissolution, liquidation or other winding-up or event.

          In the event that, notwithstanding the foregoing provisions of this
Section 12.02, the Trustee or the Holder of any Security shall have received any
payment

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                                                                            81

or distribution of assets of the Company prohibited by the foregoing
paragraph of any kind or character, whether in cash, property or securities,
before all Senior Indebtedness is paid in full or payment thereof provided
for, and if such fact shall, at or prior to the time of such payment or
distribution, have been made actually known to a Responsible Officer of the
Trustee or, as the case may be, such Holder, then and in such event such
payment or distribution shall be paid over or delivered forthwith to the
trustee in bankruptcy, receiver, liquidating trustee, custodian, assignee,
agent or other Person making payment or distribution of assets of the Company
for application to the payment of all Senior Indebtedness remaining unpaid,
to the extent necessary to pay all Senior Indebtedness in full, after giving
effect to any concurrent payment or distribution to or for the holders of
Senior Indebtedness.

          For purposes of this Article XII only, the words "cash, property or
securities" shall not be deemed to include shares of capital stock of the
Company as reorganized or readjusted, or securities of the Company or any other
corporation provided for by a plan of reorganization or readjustment which in
either case are subordinated in right of payment to all Senior Indebtedness
which may at the time be outstanding to substantially the same extent as, or to
a greater extent than, the Securities are so subordinated as provided in this
Article XII.  The consolidation of the Company with, or the merger of the
Company into, another Person or the liquidation or dissolution of the Company
following the conveyance or transfer of its properties and assets substantially
as an entirety to another Person upon the terms and conditions set forth in
Article VIII shall not be deemed a dissolution, winding-up, liquidation,
reorganization, assignment for the benefit of creditors or marshalling of assets
and liabilities of the Company for the purposes of this Section 12.02 if the
Person formed by such consolidation or into which the Company is merged or which
acquires by conveyance or transfer such properties and assets substantially as
an entirety, as the case may be, shall, as a part of such consolidation, merger,
conveyance or transfer, comply with the conditions set forth in Article VIII.

          SECTION 12.03.  NO PAYMENT WHEN SENIOR INDEBTEDNESS IN DEFAULT.
(a)  In the event and during the continuation of any default in the payment of
principal of (or premium, if any) or interest on any Senior Indebtedness beyond
any applicable grace period with respect thereto (unless and until such payment
default shall have been cured or waived in writing by the holders of such Senior
Indebtedness), or (b) in the event any judicial proceeding shall be pending with
respect to any such default, then no payment shall be made by the Company on
account of principal of (or premium, if any) or interest on the Securities or on
account of the purchase or other acquisition of Securities (including pursuant
to Articles XI and XIII).

<PAGE>

                                                                             82

          In the event that, notwithstanding the foregoing, the Company shall
make any payment to the Trustee or the Holder of any Security prohibited by the
foregoing provisions of this Section 12.03, and if such fact shall, at or prior
to the time of such payment, have been made actually known to a Responsible
Officer of the Trustee or, as the case may be, such Holder, then and in such
event such payment shall be paid over and delivered forthwith to the Company
upon Company Request.

          The provisions of this Section 12.03 shall not apply to any payment
with respect to which Section 12.02 would be applicable.

          SECTION 12.04.  PAYMENT PERMITTED IF NO DEFAULT.  Nothing contained in
this Article XII or elsewhere in this Indenture or in any of the Securities
shall prevent (a) the Company, at any time except during the pendency of any
case, proceeding, dissolution, liquidation or other winding-up, assignment for
the benefit of creditors or other marshalling of assets and liabilities of the
Company referred to in Section 12.02 or under the conditions described in
Section 12.03, from making payments at any time of principal of (and premium, if
any) or interest on the Securities, or (b) the application by the Trustee of any
money deposited with it hereunder to the payment of or on account of the
principal of (and premium, if any) or interest on the Securities or the
retention of such payment by the Holders, if, at the time of such application by
the Trustee, a Responsible Officer of the Trustee did not have actual knowledge
that such payment would have been prohibited by the provisions of this
Article XII.

          SECTION 12.05.  SUBROGATION TO RIGHTS OF HOLDERS OF SENIOR
INDEBTEDNESS.  Subject to the payment in full of all Senior Indebtedness, and
until the Securities are paid in full, the Holders of the Securities shall be
subrogated (equally and ratably with the holders of all indebtedness of the
Company which by its express terms is subordinated to indebtedness of the
Company to substantially the same extent as the Securities are subordinated and
is entitled to like rights of subrogation) to the rights of the holders of such
Senior Indebtedness to receive payments and distributions of cash, property and
securities applicable to the Senior Indebtedness to the extent that payments and
distributions otherwise payable to Holders of Securities have been applied to
the payment of Senior Indebtedness as provided by this Article XII.  For
purposes of such subrogation, no payments or distributions to the holders of the
Senior Indebtedness of any cash, property or securities to which the Holders of
the Securities or the Trustee would be entitled, except for the provisions of
this Article XII, and no payments over pursuant to the provisions of this
Article XII to the holders of Senior Indebtedness by Holders of the Securities
or the Trustee, shall, as among the Company, its creditors other than holders of
Senior Indebtedness and the Holders of the Securities, be deemed to be a payment
or distribution by the Company to or on account of the Senior Indebtedness.


<PAGE>

                                                                             83

          SECTION 12.06.  PROVISIONS SOLELY TO DEFINE RELATIVE RIGHTS.  The
provisions of this Article XII are and are intended solely for the purpose of
defining the relative rights of the Holders of the Securities on the one hand
and the holders of Senior Indebtedness on the other hand.  Nothing contained in
this Article XII or elsewhere in this Indenture or in the Securities is intended
to or shall

          (a) impair, as among the Company, its creditors other than holders of
     Senior Indebtedness and the Holders of the Securities, the obligation of
     the Company, which is absolute and unconditional (and which, subject to the
     rights under this Article XII of the holders of Senior Indebtedness, is
     intended to rank equally with all other general obligations of the
     Company), to pay to the Holders of the Securities the principal of (and
     premium, if any) and interest on the Securities as and when the same shall
     become due and payable in accordance with their terms; or

          (b) affect the relative rights against the Company of the Holders of
     the Securities and creditors of the Company other than the holders of
     Senior Indebtedness; or

          (c) prevent the Trustee or the Holder of any Security from exercising
     all remedies otherwise permitted by applicable law upon default under this
     Indenture, subject to the rights, if any, under this Article XII of the
     holders of Senior Indebtedness to receive cash, property and securities
     otherwise payable or deliverable to the Trustee or such Holder.

          SECTION 12.07.  TRUSTEE TO EFFECTUATE SUBORDINATION.  Each Holder of a
Security by his acceptance thereof authorizes and directs the Trustee on his
behalf to take such action as may be necessary or appropriate to effectuate the
subordination provided in this Article XII and appoints the Trustee his
attorney-in-fact for any and all such purposes.

          SECTION 12.08.  NO WAIVER OF SUBORDINATION PROVISIONS.  No right of
any present or future holder of any Senior Indebtedness to enforce subordination
as herein provided shall at any time in any way be prejudiced or impaired by any
act or failure to act on the part of the Company or by any act or failure to
act, in good faith, by any such holder, or by any non-compliance by the Company
with the terms, provisions and covenants of this Indenture, regardless of any
knowledge thereof any such holder may


<PAGE>
                                                                             84

have or be otherwise charged with.

          Without in any way limiting the generality of the foregoing paragraph,
the holders of Senior Indebtedness may, at any time and from time to time,
without the consent of or notice to the Trustee or the Holders of the
Securities, without incurring responsibility to the Holders of the Securities
and without impairing or releasing the subordination provided in this
Article XII or the obligations hereunder of the Holders of the Securities to the
holders of Senior Indebtedness, do any one or more of the following:

          (i) change the manner, place or terms of payment or extend the time of
     payment of, or renew or alter, Senior Indebtedness, or otherwise amend or
     supplement in any manner Senior Indebtedness or any instrument evidencing
     the same or any agreement under which Senior Indebtedness is outstanding;

          (ii) sell, exchange, release or otherwise deal with any property
     pledged, mortgaged or otherwise securing Senior Indebtedness;

          (iii) release any Person liable in any manner for the collection of
     Senior Indebtedness;

          (iv) exercise or refrain from exercising any rights against the
     Company and any other Person;

          (v) apply any and all sums received from time to time to the Senior
     Indebtedness.

          SECTION 12.09.  NOTICE TO TRUSTEE.  The Company shall give prompt
written notice to the Trustee of any fact known to the Company which would
prohibit the making of any payment to or by the Trustee in respect of the
Securities.  Notwithstanding the provisions of this Article XII or any other
provision of this Indenture, the Trustee shall not be charged with knowledge of
the existence of any facts which would prohibit the making of any payment to or
by the Trustee in respect of the Securities, unless and until the Trustee shall
have received written notice thereof from the Company or a holder of Senior
Indebtedness or from any trustee therefor; and, prior to the receipt of any such
written notice, the Trustee, subject to the provisions of Section 6.01, shall be
entitled in all respects to assume that no such facts exist; PROVIDED, HOWEVER,
that if the Trustee shall not have received the notice provided for in this
Section 12.09 at least two Business Days prior to the date upon which by the
terms hereof any money may become payable for any purpose (including, without
limitation, the payment of the principal of (and premium, if any) or interest on
any Security), then, anything herein contained to the contrary


<PAGE>
                                                                             85

notwithstanding, the Trustee shall have full power and authority to receive
such money and to apply the same to the purpose for which such money was
received and shall not be affected by any notice to the contrary which may be
received by it within two Business Days prior to such date.

          Subject to the provisions of Section 6.01, the Trustee shall be
entitled to rely on the delivery to it of a written notice by a Person
representing himself to be a holder of Senior Indebtedness (or a trustee
therefor) to establish that such notice has been given by a holder of Senior
Indebtedness (or a trustee therefor).  In the event that the Trustee determines
in good faith that further evidence is required with respect to the right of any
Person as a holder of Senior Indebtedness to participate in any payment or
distribution pursuant to this Article XII, the Trustee may request such Person
to furnish evidence to the reasonable satisfaction of the Trustee as to the
amount of Senior Indebtedness held by such Person, the extent to which such
Person is entitled to participate in such payment or distribution and any other
facts pertinent to the rights of such Person under this Article XII, and if such
evidence is not furnished, the Trustee may defer any payment to such Person
pending judicial determination as to the right of such Person to receive such
payment.

          SECTION 12.10.  RELIANCE ON JUDICIAL ORDER OR CERTIFICATE OF
LIQUIDATING AGENT.  Upon any payment or distribution of assets of the Company
referred to in this Article XII, the Trustee, subject to the provisions of
Section 6.01, and the Holders of the Securities shall be entitled to rely upon
any order or decree entered by any court of competent jurisdiction in which such
insolvency, bankruptcy, receivership, liquidation, reorganization, dissolution,
winding up or similar case or proceeding is pending, or a certificate of the
trustee in bankruptcy, receiver, liquidating trustee, custodian, assignee for
the benefit of creditors, agent or other Person making such payment or
distribution, delivered to the Trustee or to the Holders of Securities, for the
purpose of ascertaining the Persons entitled to participate in such payment or
distribution, the holders of the Senior Indebtedness and other indebtedness of
the Company, the amount thereof or payable thereon, the amount or amounts paid
or distributed thereon and all other facts pertinent thereto or to this
Article XII.

          SECTION 12.11.  TRUSTEE NOT FIDUCIARY FOR HOLDERS OF SENIOR
INDEBTEDNESS.  The Trustee shall not be deemed to owe any fiduciary duty to
the holders of Senior Indebtedness and shall not be liable to any such
holders if it shall in good faith mistakenly pay over or distribute to
Holders of Securities or to the Company or to any

<PAGE>
                                                                             86

other Person cash, property or securities to which any holders of Senior
Indebtedness shall be entitled by virtue of this Article XII or otherwise.

          SECTION 12.12.  RIGHTS OF TRUSTEE AS HOLDER OF SENIOR INDEBTEDNESS;
PRESERVATION OF TRUSTEE'S RIGHTS.  The Trustee in its individual capacity shall
be entitled to all the rights set forth in this Article XII with respect to any
Senior Indebtedness which may at any time be held by it, to the same extent as
any other holder of Senior Indebtedness, and nothing in this Indenture shall
deprive the Trustee of any of its rights as such holder.

          Nothing in this Article XII shall apply to claims of, or payments to,
the Trustee under or pursuant to Section 6.07.

          SECTION 12.13.  ARTICLE APPLICABLE TO PAYING AGENTS.  In case at any
time any Paying Agent other than the Trustee shall have been appointed by the
Company and be then acting hereunder, the term "Trustee" as used in this
Article XII shall in such case (unless the context otherwise requires) be
construed as extending to and including such Paying Agent within its meaning as
fully for all intents and purposes as if such Paying Agent were named in this
Article XII in addition to or in place of the Trustee; PROVIDED, HOWEVER, that
Section 12.12 shall not apply to the Company or any Affiliate of the Company if
it or such Affiliate acts as Paying Agent.

          SECTION 12.14.  CERTAIN CONVERSIONS DEEMED PAYMENT.  For the purposes
of this Article XII only, (1) the issuance and delivery of junior securities
upon conversion of Securities in accordance with Article XIII shall not be
deemed to constitute a payment or distribution on account of the principal of or
premium or interest on Securities or on account of the purchase or other
acquisition of Securities, and (2) the payment, issuance or delivery of cash,
property or securities (other than junior securities) upon conversion of a
Security shall be deemed to constitute payment on account of the principal of
such Security.  For the purposes of this Section 12.14, the term "junior
securities" means (a) shares of any stock of any class of the Company and
(b) securities of the Company which are subordinated in right of payment to the
prior payment in full of all Senior Indebtedness which may be outstanding at the
time of issuance or delivery of such securities to substantially the same extent
as, or to a greater extent than, the Securities are so subordinated as provided
in this Article XII.  Nothing contained in this Article XII or elsewhere in this
Indenture or in the Securities is intended to or shall impair, as among the
Company, its creditors other than holders of Senior Indebtedness and the Holders
of the Securities, the right, which is absolute and unconditional, of the Holder
of any Security to convert such Security in accordance with Article XIII.



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                                     ARTICLE XIII

                               CONVERSION OF SECURITIES

          SECTION 13.01.  CONVERSION PRIVILEGE AND CONVERSION PRICE.  Subject
to and upon compliance with the provisions of this Article XIII, at the
option of the Holder thereof, any Security or any portion of the principal
amount thereof which is U.S.$1,000 or an integral multiple of U.S.$1,000 may
be converted at the principal amount thereof, or of such portion thereof,
into fully paid and nonassessable shares of Common Stock of the Company at
any time following the latest date of original issuance of Securities at the
conversion price, determined as hereinafter provided, in effect at the time
of conversion.  Such conversion right shall expire at the close of business
on the Business Day immediately preceding October 1, 2006, subject, in the
case of conversion of any Global Security, to any Applicable Procedures.  In
case a Security or portion thereof is called for redemption at the election
of the Company or the Holder thereof exercised his right to require the
Company to purchase the Security, such conversion right in respect of the
Security or portion so called shall expire at the close of business, New York
or time, on the Business Day immediately preceding the corresponding
Redemption Date or Purchase Date, as the case may be, unless the Company
defaults in making the payment due upon redemption or purchase, as the case
may be (in each case subject as aforesaid to any Applicable Procedures with
respect to any Global Security).

          The price at which shares of Common Stock shall be delivered upon
conversion (herein called the "conversion price") shall be initially U.S.$123.00
per share of Common Stock.  The conversion price shall be adjusted in certain
instances as provided in Section 13.04.

          In case the Company shall, by dividend or otherwise, declare or
make a distribution on its Common Stock referred to in paragraph (4) or (5)
of Section 13.04, the Holder of each Security, upon the conversion thereof
pursuant to this Article XIII subsequent to the close of business on the date
fixed for the determination of shareholders entitled to receive such
distribution and prior to the effectiveness of the conversion price
adjustment in respect of such distribution pursuant to paragraph (4) or (5)
of Section 13.04, shall also be entitled to receive for each share of Common
Stock into which such Security is converted, the portion of the evidences of
indebtedness, shares of capital stock, securities, cash and other property so
distributed applicable to one share of Common Stock; PROVIDED, HOWEVER, that,
at the election of the Company (whose election shall be evidenced by a Board
Resolution) with respect to all Holders so converting, the Company may, in
lieu of distributing to such Holder any portion of such distribution not



<PAGE>
                                                                             88

consisting of cash or securities of the Company, pay such Holder an amount in
cash equal to the fair market value thereof (as determined in good faith by
the Board of Directors, whose determination shall be conclusive and described
in a Board Resolution).  If any conversion of a Security described in the
immediately preceding sentence occurs prior to the payment date for a
distribution to holders of Common Stock which the Holder of the Security so
converted is entitled to receive in accordance with the immediately preceding
sentence, the Company may elect (such election to be evidenced by a Board
Resolution) to distribute to such Holder a due bill for the evidences of
indebtedness, shares of capital stock, securities, cash or assets to which
such Holder is so entitled; PROVIDED that such due bill (i) meets any
applicable requirements of the principal national securities exchange or
other market on which the Common Stock is then traded and (ii) requires
payment or delivery of such evidences of indebtedness, shares of capital
stock, securities, cash or assets no later than the date of payment or
delivery thereof to holders of Common Stock receiving such distribution.

          SECTION 13.02.  EXERCISE OF CONVERSION PRIVILEGE.  In order to
exercise the conversion privilege, the Holder of any Security to be converted
shall surrender such Security, duly endorsed or assigned to the Company or in
blank, at any office or agency maintained by the Company pursuant to
Section 10.02, accompanied by (a) written notice (as set forth in Section 2.05
herein) to the Company at such office or agency that the Holder elects to
convert such Security or, if less than the entire principal amount thereof is to
be converted, the portion thereof to be converted and (b) if shares or any
portion of such Security not to be converted are to be issued in the name of a
Person other than the Holder thereof, and the restrictions on transfer of such
Security, set forth in the first paragraph of Section 2.02 remain in effect, a
certification of the Holder as to compliance with such restrictions (as set
forth in Section 2.07).

          If the restrictions on transfer of a Security set forth in the first
paragraph of Section 2.02 remain in effect, all shares of Common Stock delivered
upon conversion thereof shall bear a restrictive legend substantially in the
form of such paragraph.

          Except as described in the last paragraph of Section 3.07, no Holder
of Securities will be entitled upon conversion thereof to any payment or
adjustment on account of accrued and unpaid interest thereon or on account of
dividends on the shares of Common Stock issued in connection therewith.
Securities surrendered for conversion during the period from the close of
business on any Regular Record Date to the opening of business on the
corresponding Interest Payment Date (except Securities called for



<PAGE>
                                                                             89

redemption on a Redemption Date within such period between and including such
Regular Record Date and such Interest Payment Date) must be accompanied by
payment to the Company in New York Clearing House Funds or other funds
acceptable to the Company of an amount equal to the interest payable on such
Interest Payment Date on the principal amount converted.

          Securities shall be deemed to have been converted immediately prior to
the close of business on the day of surrender of such Securities for conversion
in accordance with the foregoing provisions, and at such time the rights of the
Holders of such Securities as Holders shall cease, and the Person or Persons
entitled to receive the Common Stock issuable upon conversion shall be treated
for all purposes as the record holder or holders of such Common Stock at such
time.  As promptly as practicable on or after the conversion date, the Company
shall issue and shall deliver at such office or agency a certificate or
certificates for the number of full shares of Common Stock issuable upon
conversion, together with payment in lieu of any fraction of a share as provided
in Section 13.03.

          In the case of any Security which is converted in part only, upon such
conversion the Company shall execute and the Trustee shall authenticate and
deliver to the Holder thereof, at the expense of the Company, a new Security or
Securities of authorized denominations in aggregate principal amount equal to
the unconverted portion of the principal amount of such Security.  Any
requirements for notice, surrender or delivery of Securities pursuant to this
Article XIII shall, with respect to any Global Security, be subject to any
Applicable Procedures.

          SECTION 13.03.  FRACTIONS OF SHARES.  No fractional shares of Common
Stock shall be issued upon conversion of Securities.  If more than one Security
shall be surrendered for conversion at one time by the same Holder, the number
of full shares which shall be issuable upon conversion thereof shall be computed
on the basis of the aggregate principal amount of the Securities (or specified
portions thereof) so surrendered.  Instead of any fractional share of Common
Stock which would otherwise be issuable upon conversion of any Security or
Securities (or specified portions thereof), the Company shall pay a cash
adjustment in respect of such fraction in an amount equal to the same fraction
of the Closing Price per share of the Common Stock at the close of business on
the day of conversion (or, if such day is not a Trading Day, on the Trading Day
immediately preceding such day) or, alternatively, the Company shall round up to
the next higher whole share.

          SECTION 13.04.  ADJUSTMENT OF CONVERSION PRICE.  (1) In case the
Company shall pay or make a dividend or other distribution on its Common Stock


<PAGE>
                                                                             90

exclusively in Common Stock, the conversion price in effect at the opening of
business on the day next following the date fixed for the determination of
shareholders entitled to receive such dividend or other distribution shall be
reduced by multiplying such conversion price by a fraction of which the
numerator shall be the number of shares of Common Stock outstanding at the close
of business on the date fixed for such determination and the denominator shall
be the sum of such number of shares and the total number of shares constituting
such dividend or other distribution, such reduction to become effective
immediately after the opening of business on the day next following the date
fixed for such determination.  For the purposes of this paragraph (1), the
number of shares of Common Stock at any time outstanding shall not include
shares held in the treasury of the Company but shall include shares issuable in
respect of scrip certificates issued in lieu of fractions of shares of Common
Stock.  The Company shall not pay any dividend or make any distribution on
shares of Common Stock held in the treasury of the Company.

          (2)  In case the Company shall pay or make a dividend or other
distribution on its Common Stock consisting exclusively of, or shall otherwise
issue to all holders of its Common Stock, rights, warrants or options entitling
the holders thereof to subscribe for or purchase shares of Common Stock at a
price per share less than the current market price per share (determined as
provided in paragraph (7) of this Section 13.04) of the Common Stock on the date
fixed for the determination of shareholders entitled to receive such rights,
warrants or options, the conversion price in effect at the opening of business
on the day following the date fixed for such determination shall be reduced by
multiplying such conversion price by a fraction of which the numerator shall be
the number of shares of Common Stock outstanding at the close of business on the
date fixed for such determination plus the number of shares of Common Stock
which the aggregate of the offering price of the total number of shares of
Common Stock so offered for subscription or purchase would purchase at such
current market price and the denominator shall be the number of shares of Common
Stock outstanding at the close of business on the date fixed for such
determination plus the number of shares of Common Stock so offered for
subscription or purchase, such reduction to become effective immediately after
the opening of business on the day following the date fixed for such
determination.  For the purposes of this paragraph (2), the number of shares of
Common Stock at any time outstanding shall not include shares held in the
treasury of the Company but shall include shares issuable in respect of scrip
certificates issued in lieu of fractions of shares of Common Stock.  The Company
shall not issue any rights, warrants or options in respect of shares of Common
Stock held in the


<PAGE>
                                                                             91

treasury of the Company.

          (3)  In case outstanding shares of Common Stock shall be subdivided
into a greater number of shares of Common Stock, the conversion price in effect
at the opening of business on the day following the day upon which such
subdivision becomes effective shall be proportionately reduced, and, conversely,
in case outstanding shares of Common Stock shall each be combined into a smaller
number of shares of Common Stock, the conversion price in effect at the opening
of business on the day following the day upon which such combination becomes
effective shall be proportionately increased, such reduction or increase, as the
case may be, to become effective immediately after the opening of business on
the day following the day upon which such subdivision or combination becomes
effective.

          (4)  Subject to the last sentence of this paragraph (4), in case the
Company shall, by dividend or otherwise, distribute to all holders of its Common
Stock evidences of its indebtedness, shares of any class of capital stock,
securities, cash or property (excluding any rights, warrants or options referred
to in paragraph (2) of this Section 13.04, any dividend or distribution paid
exclusively in cash and any dividend or distribution referred to in
paragraph (1) of this Section 13.04), the conversion price shall be reduced so
that the same shall equal the price determined by multiplying the conversion
price in effect immediately prior to the effectiveness of the conversion price
reduction contemplated by this paragraph (4) by a fraction of which the
numerator shall be the current market price per share (determined as provided in
paragraph (7) of this Section 13.04) of the Common Stock on the date of such
effectiveness less the fair market value (as determined in good faith by the
Board of Directors, whose determination shall be conclusive and described in a
Board Resolution and shall, in the case of securities being distributed for
which prior thereto there is an actual or when issued trading market, be no less
than the value determined by reference to the average of the closing prices in
such market over the period specified in the succeeding sentence), on the date
of such effectiveness, of the portion of the evidences of indebtedness, shares
of capital stock, securities, cash and property so distributed applicable to one
share of Common Stock and the denominator shall be such current market price per
share of the Common Stock, such reduction to become effective immediately prior
to the opening of business on the day next following the later of (a) the date
fixed for the payment of such distribution and (b) the date 20 days after the
notice relating to such distribution is given pursuant to Section 13.06(a) (such
later date of (a) and (b) being referred to as the "Reference Date").  If the
Board of Directors determines the fair market value of any distribution for
purposes of this paragraph (4) by reference to the actual or when issued trading
market for any securities comprising such distribution, it must in doing so
consider the prices in such market over the same period used in computing the
current market price per share pursuant to paragraph (7) of this Section.  For
purposes of this paragraph (4), any


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                                                                             92

dividend or distribution that includes shares of Common Stock or rights,
warrants or options to subscribe for or purchase shares of Common Stock shall
be deemed instead to be (a) a dividend or distribution of the evidences of
indebtedness, cash, property, shares of capital stock or securities other
than such shares of Common Stock or such rights, warrants or options (making
any conversion price reduction required by this paragraph (4)) immediately
followed by (b) a dividend or distribution of such shares of Common Stock or
such rights (making any further conversion price reduction required by
paragraph (1) or (2) of this Section 13.04, except (i) the Reference Date of
such dividend or distribution as defined in this paragraph (4) shall be
substituted as "the date fixed for the determination of shareholders entitled
to receive such dividend or other distributions", "the date fixed for the
determination of shareholders entitled to receive such rights, warrants or
options" and "the date fixed for such determination" within the meaning of
paragraphs (1) and (2) of this Section 13.04 and (ii) any shares of Common
Stock included in such dividend or distribution shall not be deemed
"outstanding at the close of business on the date fixed for such
determination" within the meaning of paragraph (1) of this Section 13.04).

          (5)  In case the Company shall, by dividend or otherwise, make a
distribution to all holders of its Common Stock exclusively in cash in an
aggregate amount that, together with (i) the aggregate amount of any other
distributions to all holders of its Common Stock made exclusively in cash within
the 12 months preceding the date of payment of such distribution and in respect
of which no conversion price adjustment pursuant to this paragraph (5) has been
made and (ii) the aggregate of any cash plus the fair market value (as
determined in good faith by the Board of Directors, whose determination shall be
conclusive and described in a Board Resolution), as of the expiration of the
tender or exchange offer referred to below, of consideration payable in respect
of any tender or exchange offer by the Company or a Subsidiary for all or any
portion of the Common Stock concluded within the 12 months preceding the date of
payment of such distribution and in respect of which no conversion price
adjustment pursuant to paragraph (6) of this Section 13.04 has been made,
exceeds 12.5% of the product of the current market price per share (determined
as


<PAGE>

                                                                             93

provided in paragraph (7) of this Section 13.04) of the Common Stock on the
date fixed for shareholders entitled to receive such distribution times the
number of shares of Common Stock outstanding on such date, the conversion price
shall be reduced so that the same shall equal the price determined by
multiplying the conversion price in effect immediately prior to the
effectiveness of the conversion price reduction contemplated by this
paragraph (5) by a fraction of which the numerator shall be the current market
price per share (determined as provided in paragraph (7) of this Section 13.04)
of the Common Stock on the date of such effectiveness less the amount of cash so
distributed applicable to one share of Common Stock and the denominator shall be
such current market price per share of the Common Stock, such reduction to
become effective immediately prior to the opening of business on the later of
(a) the day following the date fixed for the payment of such distribution and
(b) the date 20 days after the notice relating to such distribution is given
pursuant to Section 13.06(a).

          (6)  In case a successful tender or exchange offer made by the Company
or any Subsidiary for all or any portion of the Common Stock shall involve an
aggregate consideration having a fair market value (as determined in good faith
by the Board of Directors, whose determination shall be conclusive and described
in a Board Resolution) at the last time (the "Expiration Time") tenders or
exchanges may be made pursuant to such tender or exchange offer (as it may be
amended) that, together with (i) the aggregate of the cash plus the fair market
value (as determined in good faith by the Board of Directors, whose
determination shall be conclusive and described in a Board Resolution), as of
the expiration of the other tender or exchange offer referred to below, of
consideration payable in respect of any other tender or exchange offer by the
Company or a Subsidiary for all or any portion of the Common Stock concluded
within the preceding 12 months and in respect of which no conversion price
adjustment pursuant to this paragraph (6) has been made and (ii) the aggregate
amount of any distributions to all holders of the Common Stock made exclusively
in cash within the preceding 12 months and in respect of which no conversion
price adjustment pursuant to paragraph (5) of this Section 13.04 has been made,
exceeds 12.5% of the product of the current market price per share (determined
as provided in paragraph (7) of this Section 13.04) of the Common Stock on the
Expiration Time times the number of shares of Common Stock outstanding
(including any tendered shares) on the Expiration Time, the conversion price
shall be reduced (but not increased) so that the same shall equal the price
determined by multiplying the conversion price in effect immediately prior to
the Expiration Time by a fraction of which the numerator shall be (i) the
product of the current market price per share (determined as provided in
paragraph (7) of this Section 13.04) of the Common Stock at the Expiration Time
times the number of shares of Common Stock outstanding (including any tendered
or exchanged shares) at the Expiration Time minus (ii) the fair market value
(determined as aforesaid) of the aggregate consideration payable to shareholders
based on the acceptance (up to any maximum specified in the terms of the tender
or exchange offer) of all shares validly tendered or exchanged and not withdrawn
as of the Expiration Time (the shares deemed so accepted, up to any such
maximum, being referred to as the "Purchased Shares") and the denominator shall
be the product of (i) such current market price per share at the Expiration Time
times (ii) such number of outstanding shares at the Expiration Time less the
number of Purchased Shares, such


<PAGE>

                                                                             94

reduction to become effective immediately prior to the opening of business on
the day following the Expiration Time.

          (7)  For the purpose of any computation under this paragraph and
paragraphs (2), (4) and (5) of this Section 13.04, the current market price per
share of Common Stock on any date in question shall be deemed to be the average
of the daily Closing Prices for the 5 consecutive Trading Days selected by the
Company commencing not more than 20 Trading Days before, and ending not later
than, the date in question; PROVIDED, HOWEVER, that (i) if the "ex" date (as
hereinafter defined) for any event (other than the issuance or distribution
requiring such computation) that requires an adjustment to the conversion price
pursuant to paragraph (1), (2), (3), (4), (5) or (6) above ("Other Event")
occurs on or after the 20th Trading Day prior to the date in question and prior
to the "ex" date for the issuance or distribution requiring such computation
(the "Current Event"), the Closing Price for each Trading Day prior to the "ex"
date for such Other Event shall be adjusted by multiplying such Closing Price by
the same fraction by which the conversion price is so required to be adjusted as
a result of such Other Event, (ii) if the "ex" date for any Other Event occurs
after the "ex" date for the Current Event and on or prior to the date in
question, the Closing Price for each Trading Day on and after the "ex" date for
such Other Event shall be adjusted by multiplying such Closing Price by the
reciprocal of the fraction by which the conversion price is so required to be
adjusted as a result of such Other Event, (iii) if the "ex" date for any Other
Event occurs on the "ex" date for the Current Event, one of those events shall
be deemed for purposes of clauses (i) and (ii) of this proviso to have an "ex"
date occurring prior to the "ex" date for the other event, and (iv) if the "ex"
date for the Current Event is on or prior to the date in question, after taking
into account any adjustment required pursuant to clause (ii) of this proviso,
the Closing Price for each Trading Day on or after such "ex" date shall be
adjusted by adding thereto the amount of any cash and the fair market value on
the date in question (as determined in good faith by the Board of Directors in a
manner consistent with any determination of such value for purposes of
paragraph (4) or (5) of this Section 13.04, whose determination shall be
conclusive and described in a Board Resolution) of the portion of the rights,
warrants, options, evidences of indebtedness, shares of capital stock,
securities, cash or property being distributed applicable to one share of Common
Stock.  For the purpose of any computation under paragraph (6) of this
Section 13.04, the current market price per share of Common Stock on any date in
question shall be deemed to be the average of the daily Closing Prices for the 5
consecutive Trading Days selected by the Company commencing on or after the
latest (the "Commencement Date") of (i) the date 20 Trading Days before the date
in question, (ii) the date of commencement of the tender

<PAGE>

                                                                              95

or exchange offer requiring such computation and (iii) the date of the last
amendment, if any, of such tender or exchange offer involving a change in the
maximum number of shares for which tenders are sought or a change in the
consideration offered, and ending not later than the date of the Expiration
Time of such tender or exchange offer (or, if such Expiration Time occurs
before the close of trading on a Trading Day, not later than the Trading Day
immediately preceding the date of such Expiration Time); PROVIDED, HOWEVER,
that if the "ex" date for any Other Event (other than the tender or exchange
offer requiring such computation) occurs on or after the Commencement Date
and on or prior to the date of the Expiration Time for the tender or exchange
offer requiring such computation, the Closing Price for each Trading Day
prior to the "ex" date for such Other Event shall be adjusted by multiplying
such Closing Price by the same fraction by which the conversion price is so
required to be adjusted as a result of such other event.  For purposes of
this paragraph, the term "ex" date, (i) when used with respect to any
issuance or distribution, means the first date on which the Common Stock
trades regular way on the relevant exchange or in the relevant market from
which the Closing Price was obtained without the right to receive such
issuance or distribution, (ii) when used with respect to any subdivision or
combination of shares of Common Stock, means the first date on which the
Common Stock trades regular way on such exchange or in such market after the
time at which such subdivision or combination becomes effective, and (iii)
when used with respect to any tender or exchange offer means the first date
on which the Common Stock trades regular way on such exchange or in such
market after the Expiration Time of such tender or exchange offer.

          (8)  The Company may make such reductions in the conversion price, in
addition to those required by paragraphs (1), (2), (3), (4), (5) and (6) of this
Section, as it considers to be advisable in order that any event treated for
Federal income tax purposes as a dividend of stock or stock rights shall not be
taxable to the recipients, or to diminish the amount of such tax payable.

          (9)  To the extent permitted by applicable law, the Company may from
time to time decrease the conversion price by any amount for any period of time
so long as (i) such period of time is at least 20 days, (ii) such decrease is
irrevocable during such period  and (iii) the Board of Directors has determined
that such a decrease is in the best interests of the Company, which
determination shall be conclusive.  No such decrease may be taken into account
when determining whether the Closing Price of the Common Stock exceeds the
conversion price for purposes of clause (i) of the third paragraph of
Section 14.07.  Whenever the conversion price is decreased pursuant to the first
sentence of this paragraph (9), the Company shall give notice of the decrease to
the Holders of Securities in the manner provided in Section 1.06 at least
15 days prior to the date the decreased conversion price takes effect, and such
notice shall state the decreased


<PAGE>

                                                                             96

conversion price and the period during which it will be in effect.

          (10)  No adjustment in the conversion price shall be required unless
such adjustment would require an increase or decrease of at least 1% in the
conversion price; PROVIDED, HOWEVER, that any adjustments which by reason of
this paragraph (10) are not required to be made shall be carried forward and
taken into account in any subsequent adjustment.

          (11)  In the event that the Company distributes rights or warrants
(other than those referred to in paragraph (2) above) pro rata to holders of
Common Stock, so long as any such rights or warrants have not expired or been
redeemed by the Company, the Company shall make proper provision so that the
Holder of any Security surrendered for conversion will be entitled to receive
upon such conversion, in addition to the Conversion Shares, a number of rights
and warrants to be determined as follows:  (i) if such conversion occurs on or
prior to the date for the distribution to the holders of rights or warrants of
separate certificates evidencing such rights or warrants (the "Distribution
Date"), the same number of rights or warrants to which a holder of a number of
shares of Common Stock equal to the number of Conversion Shares is entitled at
the time of such conversion in accordance with the terms and provisions of and
applicable to the rights or warrants, and (ii) if such conversion occurs after
such Distribution Date, the same number of rights or warrants to which a holder
of the number of shares of Common Stock into which the principal amount of such
Security so converted was convertible immediately prior to such Distribution
Date would have been entitled on such Distribution Date in accordance with the
terms and provisions of and applicable to the rights or warrants.

          SECTION 13.05.  NOTICE OF ADJUSTMENTS OF CONVERSION PRICE.  Whenever
the conversion price is adjusted as herein provided:

          (a) the Company shall compute the adjusted conversion price in
     accordance with Section 13.04 and shall prepare a certificate signed by the
     Treasurer of the Company setting forth the adjusted conversion price and
     showing in reasonable detail the facts upon which such adjustment is based,
     and such certificate shall forthwith be filed (with a copy to the Trustee)
     at each office or agency maintained for the purpose of conversion of
     Securities pursuant to Section 10.02; and

          (b) a notice stating that the conversion price has been adjusted and
     setting forth the adjusted conversion price shall forthwith be required,
     and as soon as practicable after it is required, such notice shall be
     mailed by the Company to all Holders at their last addresses as they shall
     appear in the Security Register.




<PAGE>

                                                                         97



          SECTION 13.06.  NOTICE OF CERTAIN CORPORATE ACTION.  In case:

          (a) the Company shall declare a dividend (or any other distribution)
     on its Common Stock that would require a conversion price adjustment
     pursuant to paragraph (5) of Section 13.04; or

          (b) the Company shall authorize the granting to all holders of its
     Common Stock of rights, warrants or options to subscribe for or purchase
     any shares of capital stock of any class or of any other rights (excluding
     rights distributed pursuant to any shareholder rights plan); or

          (c) of any reclassification of the Common Stock of the Company (other
     than a subdivision or combination of its outstanding shares of Common
     Stock), or of any consolidation or merger to which the Company is a party
     and for which approval of any shareholders of the Company is required, or
     of the sale or transfer of all or substantially all of the assets of the
     Company; or

          (d) of the voluntary or involuntary dissolution, liquidation or
     winding, up of the Company; or

          (e) the Company or any Subsidiary of the Company shall commence a
     tender or exchange offer for all or a portion of the Company's outstanding
     shares of Common Stock (or shall amend any such tender or exchange offer);

then the Company shall cause to be filed at each office or agency maintained for
the purpose of conversion of Securities pursuant to Section 10.02, and shall
cause to be mailed to all Holders at their last addresses as they shall appear
in the Security Register, at least 20 days (or 10 days in any case specified in
clause (a) or (b) above) prior to the applicable record, effective or expiration
date hereinafter specified, a notice stating (x) the date on which a record is
to be taken for the purpose of such dividend, distribution or granting of
rights, warrants or options, or, if a record is not to be taken, the date as of
which the holders of Common Stock of record to be entitled to such dividend,
distribution, rights, warrants or options are to be determined, or (y) the date
on which such reclassification, consolidation, merger, sale, transfer,
dissolution, liquidation or winding up is expected to become effective, and the
date as of which it is expected that holders of Common Stock of record shall be
entitled to exchange their shares of Common


<PAGE>

                                                                         98

Stock for securities, cash or other property deliverable upon such
reclassification, consolidation, merger, sale, transfer, dissolution,
liquidation or winding up, or (z) the date on which such tender offer
commenced, the date on which such tender offer is scheduled to expire unless
extended, the consideration offered and the other material terms thereof (or
the material terms of any amendment thereto).

          SECTION 13.07.  COMPANY TO RESERVE COMMON STOCK.  The Company shall at
all times reserve and keep available, free from preemptive rights, out of its
authorized but unissued Common Stock, solely for the purpose of effecting the
conversion of Securities, the whole number of shares of Common Stock then
issuable upon the conversion in full of all outstanding Securities.

          SECTION 13.08.  TAXES ON CONVERSIONS. The Company will pay any and all
taxes that may be payable in respect of the issue or delivery of shares of
Common Stock on conversion of Securities pursuant hereto. The Company shall not,
however, be required to pay any tax which may be payable in respect of any
transfer involved in the issue and delivery of shares of Common Stock in a name
other than that of the Holder of the Security or Securities to be converted, and
no such issue or delivery shall be made unless and until the Person requesting
such issue has paid to the Company the amount of any such tax, or has
established to the satisfaction of the Company that such tax has been paid.

          SECTION 13.09.  COVENANT AS TO COMMON STOCK.  The Company covenants
that all shares of Common Stock which may be issued upon conversion of
Securities will upon issue be newly issued (and not treasury shares) and be duly
authorized, validly issued, fully paid and nonassessable and, except as provided
in Section 13.08, the Company will pay all taxes, liens and charges with respect
to the issue thereof.

          SECTION 13.10.  CANCELLATION OF CONVERTED SECURITIES. All Securities
delivered for conversion shall be delivered to the Trustee to be cancelled by or
at the direction of the Trustee, which shall dispose of the same as provided in
Section 3.09.

          SECTION 13.11.  PROVISIONS IN CASE OF RECLASSIFICATION, CONSOLIDATION,
MERGER OR SALE OF ASSETS.  In the event that the Company shall be a party to any
transaction (including without limitation any (i) recapitalization or
reclassification of the Common Stock (other than a change in par value, or from
par value to no par value, or from no par value to par value, or as a result of
a subdivision or combination of the Common Stock), (ii) consolidation of the
Company with, or merger of the Company into, any other person. any merger of
another person into the Company (other than a merger


<PAGE>

                                                                         99

which does not result in a reclassification, conversion, exchange or
cancellation of outstanding shares of Common Stock of the Company), (iii)
sale or transfer of all or substantially all of the assets of the Company, or
(iv) other transaction) pursuant to which the Common Stock is converted into
the right to receive other securities, cash or other property, then lawful
provision shall be made as part of the terms of such transaction whereby the
Holder of each Security then outstanding shall have the right thereafter to
convert such Security only into (subject to funds being legally available for
such purpose under applicable law at the time of such conversion) the kind
and amount of securities, cash and other property receivable upon such
transaction by a holder of the number of shares of Common Stock into which
such Security might have been converted immediately prior to such
transaction.  The Company or the person formed by such consolidation or
resulting from such merger or which acquired such assets or which acquired
the Company's shares, as the case may be, shall execute and deliver to the
Trustee a supplemental indenture establishing such rights.  Such supplemental
indenture shall provide for adjustments which, for events subsequent to the
effective date of such supplemental indenture, shall be as nearly equivalent
as may be practicable to the adjustments provided for in this Article.  The
above provisions of this Section 13.11 shall similarly apply to successive
transactions of the foregoing type.

          SECTION 13.12.  TRUSTEE ADJUSTMENT DISCLAIMER.  The Trustee has no
duty to determine when an adjustment under this Article XIII should be made, how
it should be made or what it should be.  The Trustee has no duty to determine
whether a supplemental indenture need be entered into or whether any provisions
of any supplemental indenture are correct.  The Trustee shall not be accountable
for and makes no representation as to the validity or value of any securities or
assets issued upon conversion of Securities.  The Trustee shall not be
responsible for the Company's failure to comply with this Article XIII.


                                     ARTICLE XIV

                              RIGHT TO REQUIRE PURCHASE

          SECTION 14.01.  RIGHT TO REQUIRE PURCHASE.  In the event that there
shall occur a Change in Control, then each Holder shall have the right, at such
Holder's option, to require the Company, subject to the provisions of
Section 12.03, to purchase all or any designated part of such Holder's
Securities on the date (the "Purchase Date") fixed by the Company that is not
less than 30 days nor more than 45 days after the date the Company gives notice
of the Change in Control as contemplated in Section 14.03(a) at a price (the
"Purchase Price") equal to 100% of the principal amount thereof, together with
accrued


<PAGE>

                                                                        100

and unpaid interest through the Purchase Date. Such right to require the
purchase of Securities shall not continue after a discharge of the Company
from its obligations with respect to the Securities in accordance with
Article IV. At the option of the Company, the Purchase Price may be paid in
cash or, subject to the fulfillment by the Company of the conditions set
forth Section 14.02 hereof, by delivery of shares of Common Stock in
accordance with Section 14.02. Whenever in this Indenture (including Sections
2.02, 3.01, 5.01(1) and 5.08) there is a reference, in any context, to the
principal of any Security as of any time, such reference shall be deemed to
include reference to the Purchase Price payable in respect of such Security
to the extent that such Purchase Price is, was or would be so payable at such
time, and express mention of the Purchase Price in any provision of this
Indenture shall not be construed as excluding the Purchase Price in those
provisions of this Indenture when such express mention is not made.  Any
requirements for notice, surrender or delivery of Securities pursuant to this
Article XIV shall, with respect to any Global Security, be subject to any
Applicable Procedures.

          SECTION 14.02.  CONDITIONS AND PROCEDURES RELATING TO THE COMPANY'S
ELECTION TO PAY THE PURCHASE PRICE IN COMMON STOCK.  (a)  The Company may elect
to pay the Purchase Price by delivery of shares of Common Stock pursuant to
Section 14.01 so long as the following conditions precedent are satisfied:

          (i)  The shares of Common Stock deliverable in payment of the Purchase
Price shall have a fair market value as of the Purchase Date of not less than
the Purchase Price. For purposes of Section 14.01 and this Section 14.02, the
fair market value of shares of Common Stock shall be determined by the Company
and shall be equal to 95% of the average of the Closing Prices of the Common
Stock for the five consecutive Trading Days immediately preceding and including
the third Trading Day prior to the Purchase Date;

          (ii)  The shares of Common Stock to be issued upon purchase of Notes
pursuant to this Article XIV (A) shall not require registration under any
federal securities law before such shares may be freely transferable without
being subject to any transfer restrictions under the Securities Act upon
purchase pursuant to this Article XIV or, if such registration is required, such
registration shall be completed and shall become effective prior to the Purchase
Date, and (B) shall not require registration with or approval of any
governmental authority under any state law or any other federal law before such
shares may be validly issued or delivered upon purchase pursuant to this
Article XIV or if such registration is required or such approval must be
obtained, such


<PAGE>

                                                                        101

registration shall be completed or such approval shall be obtained prior to
the Purchase Date;

          (iii)  The shares of Common Stock to be issued upon purchase of Notes
pursuant to this Article XIV are, or shall have been, approved for listing on
Nasdaq or the New York Stock Exchange or listed on another national securities
exchange, in any case, prior to the Purchase Date; and

          (iv)  All shares of Common Stock which may be issued upon purchase of
Notes pursuant to this Article XIV will be issued out of the Company's
authorized but unissued Common Stock and, will upon issue, be duly and validly
issued and fully paid and non-assessable and free of any preemptive or similar
rights.

          If all of the conditions set forth in this Section 14.02(a) are not
satisfied in accordance with the terms hereof, the Purchase Price shall be paid
by the Company only in cash.

          (b)  Any issuance of shares of Common Stock in respect of the Purchase
Price shall be deemed to have been effected immediately prior to the close of
business on the Purchase Date and the Person or Persons in whose name or names
any certificate or certificates for shares of Common Stock shall be issuable
upon such purchase shall be deemed to have become on the Purchase Date the
holder or holders of record of the shares represented thereby; PROVIDED,
HOWEVER, that any surrender for purchase on a date when the stock transfer books
of the Company shall be closed shall constitute the Person or Persons in whose
name or names the certificate or certificates for such shares are to be issued
as the record holder or holders thereof for all purposes at the opening of
business on the next succeeding day on which such stock transfer books are open.
No payment or adjustment shall be made for dividends or distributions on any
Common Stock issued upon purchase of any Note pursuant to this Article XIV
declared prior to the Purchase Date.

          (c)  No fractions of shares shall be issued upon purchase of Notes
pursuant to this Article XIV. If more than one Note shall be purchased from the
same Holder and the Purchase Price shall be payable in shares of Common Stock,
the number of full shares which shall be issuable upon such purchase shall be
computed on the basis of the aggregate principal amount of the Notes so
purchased. Instead of any fractional share of Common Stock which would otherwise
be issuable on the purchase of any Note or Notes pursuant to this Article XIV,
the Company will deliver to the applicable Holder its check for the current
market value of such fractional share. The current market value of a fraction of
a share is determined by multiplying the Closing Price of a full share on the


<PAGE>

                                                                        102

Trading Day immediately preceding the Purchase Date by the fraction, and
rounding the result to the nearest cent.

          (d)  Any issuance and delivery of certificates for shares of Common
Stock on purchase of Notes pursuant to this Article XIV shall be made without
charge to the Holder of Notes being purchased for such certificates or for any
tax or duty in respect of the issuance or delivery of such certificates or the
Notes represented thereby; PROVIDED, HOWEVER, that the Company shall not be
required to pay any tax or duty which may be payable in respect of (i) income of
the Holder or (ii) any transfer involved in the issuance or delivery of
certificates for shares of Common Stock in a name other than that of the Holder
of the Notes being purchased, and no such issuance or delivery shall be made
unless and until the Person requesting such issuance or delivery has paid to the
Company the amount of any such tax or duty or has established, to the
satisfaction of the Company, that such tax or duty has been paid.

          SECTION 14.03.  NOTICE, METHOD OF EXERCISING PURCHASE RIGHT.  (a)  On
or before the 15th day after the Company knows or reasonably should know a
Change in Control has occurred, the Company, or at the written request of the
Company, the Trustee (in the name and at the expense of the Company), shall give
notice of the occurrence of the Change in Control and of the purchase right set
forth herein arising as a result thereof by first-class mail, postage prepaid,
or by telefacsimile with written acknowledgment of transmittal to each Holder of
the Securities at such Holder's address appearing in the Security Register.  The
Company shall also deliver a copy of such notice of a purchase right to the
Trustee.

          Each notice of a purchase right shall state:

          (1) the Purchase Date,

          (2) the date by which the purchase right must be exercised,

          (3) the Purchase Price,

          (4) whether the Purchase Price will be paid in the form of cash or
     Common Stock as provided in this Indenture and that such determination is
     irrevocable, and


<PAGE>


                                                                        103


          (5) the instructions a Holder must follow to exercise its purchase
     right.

          No failure of the Company to give the foregoing notice shall limit any
Holder's right to exercise a purchase right. The Trustee shall have no
affirmative obligation to determine if there shall have occurred a Change in
Control.

          (b)  To exercise a purchase right, a Holder shall deliver to the
Company (or an agent designated by the Company for such purpose in the notice
referred to in (a) above) and to the Trustee on or before the 30th day after the
date of transmittal of the notice referred to in (a) above (i) written notice of
the Holder's exercise of such right, which notice shall set forth the name of
the Holder, the principal amount of the Security or Securities (or portion of a
Security) to be purchased, and a statement that an election to exercise the
purchase right is being made thereby, and (ii) the Security or Securities with
respect to which the purchase right is being exercised, duly endorsed for
transfer to the Company. Such written notice shall be irrevocable. If the
Purchase Date falls between any Regular Record Date and the corresponding
succeeding Interest Payment Date, Securities to be purchased must be accompanied
by payment from the Holder of an amount equal to the interest thereon which the
registered Holder thereof is to receive on such Interest Payment Date.

          (c)  In the event a purchase right shall be exercised in accordance
with the terms hereof, the Company shall on the Purchase Date pay or cause to be
paid in cash or shares of Common Stock, as provided herein, to the Holder
thereof the Purchase Price of the Security or Securities as to which the
purchase right had been exercised.

          SECTION 14.04.  DEPOSIT OF PURCHASE PRICE.  On or prior to the
Purchase Date, the Company shall deposit with the Trustee or with a Paying Agent
(or, if the Company is acting as its own Paying Agent, segregate and hold in
trust as provided in Section 10.03) cash or shares of Common Stock, as provided
herein, sufficient to pay the Purchase Price of the Securities which are to be
repaid on the Purchase Date.

          SECTION 14.05.  SECURITIES NOT PURCHASED ON PURCHASE DATE.  If any
Security surrendered for purchase shall not be so paid on the Purchase Date, the
principal of such Security shall, until paid, bear interest from the Purchase
Date at a rate borne by such Security.

          SECTION 14.06.  SECURITIES PURCHASED IN PART.  Any Security which is
to be purchased only in part shall be surrendered at any office or agency of the
Company designated for that purpose pursuant to Section 10.02 (with, if the
Company or the Trustee so requires, due endorsement by, or written instrument of
transfer in form satisfactory to the Company and the Trustee duly executed by,
the Holder thereof or his


<PAGE>

                                                                        104

attorney duly authorized in writing), and the Company shall execute, and the
Trustee shall authenticate and deliver to the Holder of such Security without
service charge, a new Security or Securities of any authorized denomination
as requested by such Holder, in aggregate principal amount equal to and in
exchange for the unpurchased portion of the principal of the Security so
surrendered.

          SECTION 14.07.  CERTAIN DEFINITIONS.  For purposes of this Article:
The term "Beneficial Owner" shall be determined in accordance with Rules 13d-3
and 13d-5 promulgated by the Commission under the Exchange Act, or any successor
provision thereto, except that a Person shall be deemed to have "beneficial
ownership" of all shares that such Person has the right to acquire, whether such
right is exercisable immediately or only after the passage of time.

          A "Change in Control" shall be deemed to have occurred at such time as
(a) any Person, or any Persons acting together in a manner which would
constitute a "group" (a "Group") for purposes of Section 13(d) of the Exchange
Act, or any successor provision thereto, together with any Affiliates thereof,
(i) become the Beneficial Owners, directly or indirectly, of capital stock of
the Company, entitling such Person or Persons and its or their Affiliates to
exercise more than 50% of the total voting power of all classes of the Company's
capital stock entitled to vote generally in the election of directors or
(ii) shall succeed in having sufficient of its or their nominees (who are not
supported by a majority of the then current Board of Directors of the Company)
elected to the Board of Directors of the Company such that such nominees, when
added to any existing directors remaining on the Board of Directors of the
Company after such election who are Affiliates of or acting in concert with any
such Persons, shall constitute a majority of the Board of Directors of the
Company, (b) the Company shall be a party to any transaction pursuant to which
the Common Stock is converted into the right to receive other securities (other
than common stock), cash and/or property (or the Company, by dividend, tender or
exchange offer or otherwise, distributes other securities, cash and/or property
to holders of Common Stock) and the value of all such securities, cash and/or
property distributed in such transaction and any other transaction effected
within the 12 months preceding consummation of such transaction (as determined
in good faith by the Board of Directors, whose determination shall be conclusive
and described in a Board Resolution) is more than 50% of the average of the
daily Closing Prices for the five consecutive Trading Days ending on the Trading
Day immediately preceding the date of such transaction (or, if earlier, the
Trading Day immediately preceding the ex date (as defined in paragraph (7) of
Section 13.04) for such transaction) or (c) the Company shall consolidate with
or merge into any other Person or sell, convey, transfer or lease its properties
and assets substantially as an entirety to any Person other than a Subsidiary,
or any other Person shall consolidate with or merge into the Company


<PAGE>

                                                                        105

(other than, in the case of this clause (c), pursuant to any consolidation or
merger where Persons who are shareholders of the Company immediately prior
thereto become the Beneficial Owners of shares of capital stock of the
surviving company entitling such Persons to exercise more than 50% of the
total voting power of all classes of such surviving company's capital stock
entitled to vote generally in the election of directors).

          Notwithstanding the foregoing, a "Change in Control" will be deemed
not to have occurred (i) if the Closing Price of the Common Stock for any five
Trading Days during the ten Trading Days immediately preceding the Change in
Control is at least equal to 105% of the conversion price in effect immediately
preceding the Change in Control or (ii) if at least 90% of the consideration
(excluding cash payments for fractional shares or cash payments for appraisal
rights) received or to be received by the shareholders of the Company in the
transaction or transactions constituting the Change in Control consists of (x)
shares of common stock of an entity organized and validly existing under the
laws of the United States of America, any State thereof or the District of
Columbia the common stock of which is, or upon issuance will be, traded on a
national securities exchange in the United States of America or through Nasdaq
or (y) shares of common stock of an entity organized and validly existing under
the laws of a jurisdiction outside of the United States of America, or American
Depositary Shares representing such shares of common stock, that are, or upon
issuance will be, traded on a national securities exchange in the United States
of America or through Nasdaq, if such entity has a worldwide total market
capitalization of its equity securities of at least U.S. $5 billion.

                                      ARTICLE XV

                          DEFEASANCE AND COVENANT DEFEASANCE

          SECTION 15.01.  COMPANY'S OPTION TO EFFECT DEFEASANCE OR COVENANT
DEFEASANCE.  The Company may at its option by Board Resolution, at any time,
elect to have either Section 15.02 or Section 15.03 applied to the Outstanding
Securities upon compliance with the conditions set forth below in this
Article XV.

          SECTION 15.02.  DEFEASANCE AND DISCHARGE. Upon the Company's exercise
of the option provided in Section 15.01 applicable to this Section, the Company
shall be deemed to have been discharged from its obligations with respect to the
Outstanding Securities (other than those specified below), the Holders and any
holders of Senior Indebtedness, and the provisions of Article XII hereof shall
cease to be effective,


<PAGE>

                                                                        106

on the date the conditions set forth below are satisfied (hereinafter,
"defeasance"). For this purpose, such defeasance means that the Company shall
be deemed to have paid and discharged the entire indebtedness represented by
the Outstanding Securities, the Company shall be deemed to have satisfied all
their other obligations under such Securities and this Indenture insofar as
such Securities are concerned (and the Trustee, at the expense of the
Company, shall execute proper instruments acknowledging the same), except for
the following which shall survive until otherwise terminated or discharged
hereunder:  (A) the rights of Holders of such Securities to receive, solely
from the trust fund described in Section 15.04 and as more fully set forth in
such Section, payments in respect of the principal of, premium, if any and
interest on such Securities when such payments are due, (B) the Company's
obligations with respect to such Securities under Sections 3.04, 3.05, 3.06,
10.02, 10.03, 10.11, Article XIII and Article XIV, (C) the rights, powers,
trusts, duties and immunities of the Trustee hereunder and (D) this Article
XV.  Subject to compliance with this Article XV, the Company may exercise its
option under this Section 15.02 notwithstanding the prior exercise of its
option under Section 15.03.

          SECTION 15.03.  COVENANT DEFEASANCE.  Upon the Company's exercise of
the option provided in Section 15.01 applicable to this Section, (i) the Company
shall be released from its obligations under Section 10.06 and Section 10.07,
(ii) the occurrence of an event specified in Section 5.01(4) (with respect to
either of Section 10.06 or Section 10.07) or 5.01(5) shall not be deemed to be
an Event of Default and (iii) the provisions of Article XII hereof shall cease
to be effective on and after the date the conditions set forth below are
satisfied (hereinafter, "covenant defeasance"). For this purpose, such covenant
defeasance means that the Company may omit to comply with and shall have no
liability in respect of any term, condition or limitation set forth in any such
Section or Article, whether directly or indirectly by reason of any reference
elsewhere herein to any such Section or Article or by reason of any reference in
any such Section or Article to any other provision herein or in any other
document, but the remainder of this Indenture and such Securities shall be
unaffected thereby.

          SECTION 15.04.  CONDITIONS TO DEFEASANCE OR COVENANT DEFEASANCE.  The
following shall be the conditions to application of either Section 15.02 or
Section 15.03 to the then Outstanding Securities:

          (1)  The Company shall irrevocably have deposited or caused to be
     deposited with the Trustee (or another trustee satisfying the requirements
     of Section 6.09 who shall agree to comply with the provisions of this
     Article XV applicable to it) as trust funds in trust for the purpose of
     making the following payments, specifically pledged as security for, and
     dedicated solely to, the benefit of


<PAGE>

                                                                        107


     the Holders of such Securities, (A) money in an amount, or (B) U.S.
     Government Obligations which through the scheduled payment of principal
     and interest in respect thereof in accordance with their terms will
     provide, not later than one day before the due date of any payment,
     money in an amount, or (C) a combination thereof, sufficient, in the
     written opinion of a nationally recognized firm of independent public
     accountants expressed in a written certification thereof delivered to
     the Trustee, to pay and discharge, and which shall be applied by the
     Trustee (or other qualifying trustee) to pay and discharge, the
     principal of, premium, if any, and each installment of interest on the
     Securities on the Stated Maturity of such principal or installment of
     interest in accordance with the terms of this Indenture and of such
     Securities. For this purpose, "U.S. Government Obligations" means
     securities that are (x) direct obligations of the United States of
     America for the payment of which its full faith and credit is pledged or
     (y) obligations of a Person controlled or supervised by and acting as an
     agency or instrumentality of the United States of America the payment of
     which is unconditionally guaranteed as a full faith and credit
     obligation by the United States of America, which, in either case, are
     not callable or redeemable at the option of the issuer thereof, and
     shall also include a depository receipt issued by a bank (as defined in
     Section 3(a)(2) of the Securities Act) as custodian with respect to any
     such U.S. Government Obligation or a specific payment of principal of or
     interest on any such U.S. Government Obligation held by such custodian
     for the account of the holder of such depository receipt; PROVIDED that
     (except as required by law) such custodian is not authorized to make any
     deduction from the amount payable to the holder of such depository
     receipt from any amount received by the custodian in respect of the U.S.
     Government Obligation or the specific payment of principal of or
     interest on the U.S. Government Obligation evidenced by such depository
     receipt.

          (2)  In the case of an election under Section 15.02, the Company shall
     have delivered to the Trustee an Opinion of Counsel stating that (x) the
     Company has received from, or there has been published by, the Internal
     Revenue Service a ruling, or (y) since the date of this Indenture there has
     been a change in the applicable Federal income tax law, in either case to
     the effect that, and based thereon such opinion shall confirm that, the
     Holders of the Outstanding Securities will not recognize gain or loss for
     Federal income tax purposes as a result of such deposit, defeasance and
     discharge and will be subject to Federal income tax on the same amount, in
     the same manner and at the same times as would have been the case if such
     deposit, defeasance and discharge had not occurred.

<PAGE>
                                                                        108


          (3)  In the case of an election under Section 15.03, the Company shall
     have delivered to the Trustee an Opinion of Counsel to the effect that the
     Holders of the Outstanding Securities will not recognize gain or loss for
     Federal income tax purposes as a result of such deposit and covenant
     defeasance and will be subject to Federal income tax on the same amount, in
     the same manner and at the same times as would have been the case if such
     deposit and covenant defeasance had not occurred.

          (4)  The Company shall have delivered to the Trustee an Officers'
     Certificate to the effect that the Securities, if then listed on any
     securities exchange, will not be delisted as a result of such deposit.

          (5)  Such defeasance or covenant defeasance shall not cause the
     Trustee to have a conflicting interest as defined in Section 6.08 and for
     purposes of the Trust Indenture Act with respect to any securities of the
     Company.

          (6)  At the time of such deposit: (A) no default in the payment of all
     or a portion of principal of (or premium, if any) or interest on or other
     obligations in respect of any Senior Indebtedness shall have occurred and
     be continuing, and no event of default with respect to any Senior
     Indebtedness shall have occurred and be continuing and shall have resulted
     in such Senior Indebtedness becoming or being declared due and payable
     prior to the date on which it would otherwise have become due and payable
     and (B) no other event with respect to any Senior Indebtedness shall have
     occurred and be continuing permitting (after notice or the lapse of time,
     or both) the holders of such Senior Indebtedness (or a trustee on behalf of
     the holders thereof) to declare such Senior Indebtedness due and payable
     prior to the date on which it would otherwise have become due and payable,
     or, in the case of either clause (A) or clause (B) above, each such default
     or event of default shall have been cured or waived or shall have ceased to
     exist.

          (7)  No Event of Default or event which with notice or lapse of time
     or both would become an Event of Default shall have occurred and be
     continuing on the date of such deposit or, insofar as subsections 5.01(6)
     and (7) are concerned, at any time during the period ending on the
     121st day after the date of such deposit (it being understood that this
     condition shall not be deemed satisfied until the expiration of such
     period).

          (8)  Such defeasance or covenant defeasance shall not result in a
     breach or violation of, or constitute a default under, any other agreement
     or instrument to


<PAGE>
                                                                        109


     which the Company is a party or by which it is bound.

          (9)  The Company shall have delivered to the Trustee an Officers'
     Certificate and an Opinion of Counsel, each stating that all conditions
     precedent provided for relating to either the defeasance under
     Section 15.02 or the covenant defeasance under Section 15.03 and Section
     15.04 (as the case may be) have been complied with.

          (10)  Such defeasance or covenant defeasance shall not result in the
     trust arising from such deposit constituting an investment company as
     defined in the Investment Company Act of 1940, as amended, or such trust
     shall be qualified under such act or exempt from regulation thereunder.

          SECTION 15.05.  DEPOSITED MONEY AND U.S. GOVERNMENT OBLIGATIONS TO
BE HELD IN TRUST; OTHER MISCELLANEOUS PROVISIONS.  Subject to the provisions
of the last paragraph of Section 10.03, all money and U.S. Government
Obligations (including the proceeds thereof) deposited with the Trustee (or
other qualifying trustee collectively, for purposes of this Section 15.05,
the "Trustee") pursuant to Section 15.04 in respect of the Securities shall
be held in trust and applied by the Trustee, in accordance with the
provisions of such Securities and this Indenture, to the payment, either
directly or through any Paying Agent (including the Company acting as its own
Paying Agent) as the Trustee may determine, to the Holders of such
Securities, of all sums due and to become due thereon in respect of
principal, premium, if any, and interest. Money so held in trust shall not be
subject to the provisions of Article XII.

          The Company shall pay and indemnify the Trustee against any tax,
fee or other charge imposed on or assessed against the U.S. Government
Obligations deposited pursuant to Section 15.04 or the principal and interest
received in respect thereof other than any such tax, fee or other charge
which by law is for the account of the Holders of the Outstanding Securities.

          Anything in this Article XV to the contrary notwithstanding, the
Trustee shall deliver or pay to the Company from time to time upon Company
Request any money or U.S. Government Obligations held by it as provided in
Section 15.04 which, in the opinion of a nationally recognized firm of
independent public accountants expressed in a written certification thereof
delivered to the Trustee, are in excess of the amount thereof which would then
be required to be deposited to effect an equivalent defeasance


<PAGE>
                                                                        110


or covenant defeasance.

          SECTION 15.06.  REINSTATEMENT.  If the Trustee or the Paying Agent
is unable to apply any money in accordance with Section 15.02 or 15.03 by
reason of any order or judgment of any court or governmental authority
enjoining, restraining or otherwise prohibiting such application, then the
Company's obligations under this Indenture and the Securities shall be
revived and reinstated as though no deposit had occurred pursuant to this
Article XV until such time as the Trustee or Paying Agent is permitted to
apply all such money in accordance with Section 15.02 or 15.03; PROVIDED,
HOWEVER, that if the Company makes any payment of principal of, premium, if
any, or interest on any Security following the reinstatement of its
obligations, the Company shall be subrogated to the rights of the Holders of
such Securities to receive such payment from the money held by the Trustee or
the Paying Agent.


                                     ARTICLE XVI

                                       IMMUNITY

          SECTION 16.01.  PERSONAL IMMUNITY OF INCORPORATORS, SHAREHOLDERS,
DIRECTORS AND OFFICERS.  No recourse for the payment of the principal of or
interest on the Securities, and no recourse under or upon any obligation,
covenant or agreement contained in this Indenture or in any indenture
supplemental hereto, or in the Securities, or because of any indebtedness
evidenced thereby, shall be had against any incorporator, or against any
past, present or future shareholder, officer or director, as such, of the
Company or any successor corporation, either directly or through the Company
or any successor corporation, under any rule of law, statute or
constitutional provision or by the enforcement of any assessment or by any
legal or equitable proceeding or otherwise, all such liability being
expressly waived and released by the acceptance of the Securities by the
Holders thereof and as part of the consideration for the issue of the
Securities. Each and every Holder of the Securities, by receiving and holding
the same, agrees to the provisions of this Section 16.01 and waives and
releases any and all such recourse, claim and liability.


<PAGE>



          This instrument may be executed in any number of counterparts, each
of which so executed shall be deemed to be an original, but all such
counterparts shall together constitute but one and the same instrument.

          IN WITNESS WHEREOF, the parties hereto have caused this Indenture
to be duly executed as of the day and year first above written.


                                    AFFYMETRIX, INC.


   by
      --------------------------
                                    Name:
                                    Title:




<PAGE>

                                    THE BANK OF NEW YORK,

                                    by
                                       ---------------------------
                                       Name:
                                       Title:



<PAGE>

                                                                 EXECUTION COPY







                                      INDENTURE


                                   AFFYMETRIX, INC.


                                          to


                                 THE BANK OF NEW YORK

                                        Trustee






                      5% Convertible Subordinated Notes Due 2006



                            Dated as of September 22, 1999





<PAGE>




                       TABLE OF CONTENTS

<TABLE>
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                                                                                               ----
                           ARTICLE I

                 DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION
<S>                                                                                            <C>
SECTION 1.01.   Definitions................................................................     1
SECTION 1.02.   Compliance Certificates and Opinions.......................................     8
SECTION 1.03.   Form of Documents Delivered to Trustee.....................................     9
SECTION 1.04.   Acts of Holders:  Record Dates.............................................     9
SECTION 1.05.   Notices, etc., to Trustee and Company......................................    11
SECTION 1.06.   Notices to Holders:  Waiver................................................    12
SECTION 1.07.   Conflict with Trust Indenture Act..........................................    12
SECTION 1.08.   Effect of Headings and Table of Contents...................................    12
SECTION 1.09.   Successors and Assigns.....................................................    12
SECTION 1.10.   Severability Clause........................................................    12
SECTION 1.11    Benefits of Indenture......................................................    12
SECTION 1.12.   Governing Law..............................................................    13
SECTION 1.13.   Legal Holidays.............................................................    13


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                           ARTICLE II

                         SECURITY FORMS
<S>                                                                                            <C>
SECTION 2.01.   Forms Generally............................................................    13
SECTION 2.02.   Form of Face of Security...................................................    14
SECTION 2.03.   Form of Reverse of Security................................................    17
SECTION 2.04.   Form of Trustee's Certificate of Authentication............................    21
SECTION 2.05.   Form of Conversion Notice..................................................    21
SECTION 2.06.   Form of Purchase Notice....................................................    23
SECTION 2.07.   Form of Certification......................................................    23


                           ARTICLE III

                         THE SECURITIES

SECTION 3.01.   Title and Terms............................................................    24
SECTION 3.02.   Denominations..............................................................    25
SECTION 3.03.   Execution, Authentication, Delivery and Dating.............................    25
SECTION 3.04.   Global and Non-Global Securities...........................................    26
SECTION 3.05.   Registration; Registration of Transfer and Exchange........................    27
SECTION 3.06.   Mutilated, Destroyed, Lost and Stolen Securities...........................    30
SECTION 3.07.   Payment of Interest; Interest Rights Preserved.............................    31
SECTION 3.08.   Persons Deemed Owners......................................................    32
SECTION 3.09.   Cancellation...............................................................    33
SECTION 3.10.   Computation of Interest....................................................    33
SECTION 3.11.   CUSIP Numbers..............................................................    33


                           ARTICLE IV

                   SATISFACTION AND DISCHARGE


                                        -115-


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<S>                                                                                            <C>
SECTION 4.01.   Satisfaction and Discharge of Indenture....................................    33
SECTION 4.02.   Application of Trust Money.................................................    34


                            ARTICLE V

                            REMEDIES

SECTION 5.01.   Events of Default..........................................................    35
SECTION 5.02.   Acceleration of Maturity; Rescission and Annulment.........................    36
SECTION 5.03.   Collection of Indebtedness and Suits for Enforcement by
                     Trustee...............................................................    37
SECTION 5.04.   Trustee May File Proofs of Claim...........................................    38
SECTION 5.05.   Trustee May Enforce Claims Without Possession of
                     Securities............................................................    38
SECTION 5.06.   Application of Money Collected.............................................    38
SECTION 5.07.   Limitation on Suits........................................................    39
SECTION 5.08.   Unconditional Right of Holders to Receive Principal,
                     Premium and Interest and To Convert...................................    39
SECTION 5.09.   Restoration of Rights and Remedies.........................................    40
SECTION 5.10.   Rights and Remedies Cumulative.............................................    40
SECTION 5.11.   Delay or Omission Not Waiver...............................................    40
SECTION 5.12.   Control by Holders.........................................................    40
SECTION 5.13.   Waiver of Past Defaults....................................................    40
SECTION 5.14.   Undertaking for Costs......................................................    41
SECTION 5.15.   Waiver of Usury, Stay or Extension Laws....................................    41


                           ARTICLE VI

                           THE TRUSTEE

SECTION 6.01.   Certain Duties and Responsibilities........................................    41
SECTION 6.02.   Notice of Defaults.........................................................    42


                                        -116-


<PAGE>

<CAPTION>

                                                                                               Page
                                                                                               ----
<S>                                                                                            <C>
SECTION 6.03.   Certain Rights of Trustee..................................................    42
SECTION 6.04.   Not Responsible for Recitals or Issuance of Securities.....................    43
SECTION 6.05.   May Hold Securities........................................................    44
SECTION 6.06.   Money Held in Trust........................................................    44
SECTION 6.07.   Compensation and Reimbursement.............................................    44
SECTION 6.08.   Disqualification; Conflicting Interests....................................    44
SECTION 6.09.   Corporate Trustee Required; Eligibility....................................    45
SECTION 6.10.   Resignation and Removal; Appointment of Successor..........................    45
SECTION 6.11.   Acceptance of Appointment by Successor.....................................    46
SECTION 6.12.   Merger, Conversion, Consolidation or Succession to
                     Business..............................................................    46
SECTION 6.13.   Preferential Collection of Claims Against Company..........................    47
SECTION 6.14.   Appointment of Authenticating Agent........................................    47
SECTION 6.15.   Appointment of Co-Trustee..................................................    48


                               ARTICLE VII

              HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY

SECTION 7.01.   Company to Furnish Trustee Names and Addresses to
                     Holders...............................................................    49
SECTION 7.02.   Preservation of Information; Communications to Holders.....................    49
SECTION 7.03.   Reports by Trustee.........................................................    49
SECTION 7.04.   Reports by Company.........................................................    50


                               ARTICLE VIII

              CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

SECTION 8.01.   Company May Consolidate, etc., Only on Certain Terms.......................    50
SECTION 8.02.   Successor Substituted......................................................    51


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                                                                                               Page
                                                                                               ----

                                ARTICLE IX

                           SUPPLEMENTAL INDENTURES
<S>                                                                                            <C>
SECTION 9.01.   Supplemental Indentures Without Consent of Holders.........................    51
SECTION 9.02.   Supplemental Indentures with Consent of Holders............................    52
SECTION 9.03.   Execution of Supplemental Indentures.......................................    53
SECTION 9.04.   Effect of Supplemental Indentures..........................................    53
SECTION 9.05.   Conformity with Trust Indenture Act........................................    53
SECTION 9.06.   Reference in Securities to Supplemental Indentures.........................    53


                                 ARTICLE X

                                 COVENANTS

SECTION 10.01.  Payment of Principal, Premium and Interest.................................    53
SECTION 10.02.  Maintenance of Office or Agency............................................    54
SECTION 10.03.  Money for Security Payments To Be Held in Trust............................    54
SECTION 10.04.  Statement by Officers as to Default........................................    55
SECTION 10.05.  Existence..................................................................    55
SECTION 10.06.  Maintenance of Properties..................................................    56
SECTION 10.07.  Payment of Taxes and Other Claims..........................................    56
SECTION 10.08.  Waiver of Certain Covenants................................................    56
SECTION 10.09.  Delivery of Certain Information............................................    56
SECTION 10.10.  Resale of Certain Securities; Reporting Issuer.............................    56
SECTION 10.11.  Registration Rights........................................................    57



                                ARTICLE XI

                          REDEMPTION OF SECURITIES


                                        -118-


<PAGE>

<CAPTION>

                                                                                               Page
                                                                                               ----
<S>                                                                                            <C>
SECTION 11.01.  Rights of Redemption.......................................................    58
SECTION 11.02.  Applicability of Article...................................................    58
SECTION 11.03.  Election to Redeem; Notice to Trustee......................................    58
SECTION 11.04.  Selection by Trustee of Securities to Be Redeemed.........................     58
SECTION 11.05.  Notice of Redemption.......................................................    59
SECTION 11.06.  Deposit of Redemption Price...............................................     59
SECTION 11.07.  Securities Payable on Redemption Date......................................    60
SECTION 11.08.  Securities Redeemed in Part................................................    60
SECTION 11.09.  Conversion Arrangement on Call for Redemption..............................    60


                                  ARTICLE XII

                          SUBORDINATION OF SECURITIES

SECTION 12.01.  Securities Subordinate to Senior Indebtedness..............................    61
SECTION 12.02.  Payment over of Proceeds upon Dissolution, Etc.............................    61
SECTION 12.03.  No Payment When Senior Indebtedness in Default.............................    62
SECTION 12.04.  Payment Permitted If No Default............................................    63
SECTION 12.05.  Subrogation to Rights of Holders of Senior Indebtedness....................    63
SECTION 12.06.  Provisions Solely to Define Relative Rights................................    63
SECTION 12.07.  Trustee to Effectuate Subordination........................................    64
SECTION 12.08.  No Waiver of Subordination Provisions......................................    64
SECTION 12.09.  Notice to Trustee..........................................................    64
SECTION 12.10.  Reliance on Judicial Order or Certificate of Liquidating
                     Agent.................................................................    65
SECTION 12.11.  Trustee Not Fiduciary for Holders of Senior Indebtedness...................    65
SECTION 12.12.  Rights of Trustee as Holder of Senior Indebtedness;
                     Preservation of Trustee's Rights......................................    66
SECTION 12.13.  Article Applicable to Paying Agents........................................    66
SECTION 12.14.  Certain Conversions Deemed Payment.........................................    66


                                        -119-


<PAGE>

<CAPTION>

                                                                                               Page
                                                                                               ----

                                  ARTICLE XIII

                            CONVERSION OF SECURITIES
<S>                                                                                            <C>
SECTION 13.01.  Conversion Privilege and Conversion Price..................................    66
SECTION 13.02.  Exercise of Conversion Privilege...........................................    67
SECTION 13.03.  Fractions of Shares........................................................    68
SECTION 13.04.  Adjustment of Conversion Price.............................................    69
SECTION 13.05.  Notice of Adjustments of Conversion Price..................................    74
SECTION 13.06.  Notice of Certain Corporate Action.........................................    74
SECTION 13.07.  Company to Reserve Common Stock............................................    75
SECTION 13.08.  Taxes on Conversions.......................................................    75
SECTION 13.09.  Covenant as to Common Stock................................................    75
SECTION 13.10.  Cancellation of Converted Securities.......................................    75
SECTION 13.11.  Provisions in Case of Reclassification, Consolidation, Merger
                     or Sale of Assets.....................................................    75
SECTION 13.12.  Trustee Adjustment Disclaimer..............................................    76


                                   ARTICLE XIV

                            RIGHT TO REQUIRE PURCHASE

SECTION 14.01.  Right to Require Purchase..................................................    76
SECTION 14.02.  Conditions and Procedures Relating to the Company's
                Election to Pay the Purchase Price in Common Stock.........................    76
SECTION 14.03.  Notice, Method of Exercising Purchase Right................................    78
SECTION 14.04.  Deposit of Purchase Price..................................................    79
SECTION 14.05.  Securities Not Purchased in Part...........................................    79
SECTION 14.06.  Securities Purchased in Part...............................................    79
SECTION 14.07.  Certain Definitions........................................................    79


                                        -120-


<PAGE>

<CAPTION>

                                                                                               Page
                                                                                               ----

                                   ARTICLE XV

                        DEFEASANCE AND COVENANT DEFEASANCE
<S>                                                                                            <C>
SECTION 15.01.  Company's Option to Effect Defeasance or Covenant
                     Defeasance............................................................    81
SECTION 15.02.  Defeasance and Discharge...................................................    81
SECTION 15.03.  Covenant Defeasance........................................................    81
SECTION 15.04.  Conditions to Defeasance or Covenant Defeasance............................    81
SECTION 15.05.  Deposited Money and U.S. Government Obligations to Be
                     Held in Trust; Other Miscellaneous Provisions.........................    83
SECTION 15.06.  Reinstatement..............................................................    84


                                  ARTICLE XVI

                                    IMMUNITY

SECTION 16.01.  Personal Immunity of Incorporators, Shareholders, Directors
                     and Officers.........................................................     84


</TABLE>



                                        -121-


<PAGE>

                                                                    EXHIBIT 5.1

                                                              December 10, 1999


Affymetrix, Inc.,
  3380 Central Expressway,
    Santa Clara, California 95051.

Dear Sirs:

     In connection with the registration under the Securities Act of 1933
(the "Act") of $150,000,000 principal amount of 5% Convertible Subordinated
Notes Due 2006 (the "Securities") of Affymetrix, Inc., a Delaware corporation
(the "Company"), and the shares of Common Stock, par value $0.01 per share,
of the Company initially issuable upon conversion of the Securities (the
"Shares"), we, as your special counsel, have examined such corporate records,
certificates and other documents, and such questions of law, as we have
considered necessary or appropriate for the purposes of this opinion.  Upon
the basis of such examination, we advise you that, in our opinion, when the
registration statement relating to the Securities and the Shares (the
"Registration Statement") has become effective under the Act,

<PAGE>

Affymetrix, Inc.                                                            -2-


the Securities will constitute valid and legally binding obligations of the
Company, subject to bankruptcy, insolvency, fraudulent transfer,
reorganization, moratorium and similar laws of general applicability relating
to or affecting creditors' rights and to general equity principles, and the
Shares, when duly issued upon conversion of the Securities, will be validly
issued, fully paid and nonassessable.

     The foregoing opinion is limited to the Federal laws of the United
States, the laws of the State of New York and the General Corporation Law of
the State of Delaware, and we are expressing no opinion as to the effect of
the laws of any other jurisdiction.

<PAGE>

Affymetrix, Inc.                                                            -3-


     Also, we have relied as to certain matters on information obtained from
public officials, officers of the Company and other sources believed by us to
be responsible, and we have assumed that the Indenture has been duly
authorized, executed and delivered by the Trustee thereunder, an assumption
which we have not independently verified.

     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the reference to us under the heading "Validity
of the Securities" in the Prospectus.  In giving such consent, we do not
thereby admit that we are in the category of persons whose consent is
required under Section 7 of the Act.

                                       Very truly yours,

                                       Sullivan & Cromwell

<PAGE>
                                  EXHIBIT 23.1

               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS

    We consent to the reference to our firm under the caption "Experts" in the
Registration Statement (Form S-3) of Affymetrix, Inc. for the registration of
$150,000,000 of 5% Convertible Subordinated Notes Due 2006 (the "Notes") and
1,219,515 shares of its Common Stock issuable upon conversion of the Notes and
to the incorporation by reference therein of our report dated January 29, 1999
(except for Note 11, as to which the date is March 25, 1999) with respect to the
financial statements and schedule of Affymetrix, Inc. included in its Annual
Report (Form 10-K) for the year ended December 31, 1998, filed with the
Securities and Exchange Commission.

                                          /s/ Ernst & Young

Palo Alto, California
December 9, 1999

<PAGE>


===============================================================================

                                   FORM T-1

                       SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549

                          STATEMENT OF ELIGIBILITY
                   UNDER THE TRUST INDENTURE ACT OF 1939 OF A
                   CORPORATION DESIGNATED TO ACT AS TRUSTEE

                    CHECK IF AN APPLICATION TO DETERMINE
                   ELIGIBILITY OF A TRUSTEE PURSUANT TO
                        SECTION 305(b)(2)  |__|

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

                               THE BANK OF NEW YORK
                (Exact name of trustee as specified in its charter)

             New York                                       13-5160382
      (State of incorporation                           (I.R.S. employer
     if not a U.S. national bank)                       identification no.)

    One Wall Street, New York, N.Y.                             10286
(Address of principal executive offices)                     (Zip code)

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

                                AFFYMETRIX, INC.
                (Exact name of obligor as specified in its charter)

         Delaware                                            77-0319159
(State or other jurisdiction of                          (I.R.S. employer
incorporation or organization)                          identification no.)

   3380 Central Expressway
   Santa Clara, California                                    95051
(Address of principal executive offices)                   (Zip code)

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

                     5% Convertible Subordinated Notes due 2006
                         (Title of the indenture securities)

===============================================================================


<PAGE>

1.  GENERAL INFORMATION.  FURNISH THE FOLLOWING INFORMATION AS TO THE TRUSTEE:

    (a)  NAME AND ADDRESS OF EACH EXAMINING OR SUPERVISING AUTHORITY TO WHICH
         IT IS SUBJECT.


<TABLE>
<CAPTION>
- ------------------------------------------------------------------------------------

              Name                                     Address
- ------------------------------------------------------------------------------------
<S>                                              <C>
    Superintendent of Banks of the State of      2 Rector Street, New York,
    New York                                     N.Y.  10006, and Albany, N.Y. 12203

    Federal Reserve Bank of New York             33 Liberty Plaza, New York,
                                                 N.Y.  10045

    Federal Deposit Insurance Corporation        Washington, D.C.  20429

    New York Clearing House Association          New York, New York   10005
</TABLE>

    (b)  WHETHER IT IS AUTHORIZED TO EXERCISE CORPORATE TRUST POWERS.

    Yes.

2.  AFFILIATIONS WITH OBLIGOR.

    IF THE OBLIGOR IS AN AFFILIATE OF THE TRUSTEE, DESCRIBE EACH SUCH
    AFFILIATION.

    None.

16.  LIST OF EXHIBITS.

     EXHIBITS IDENTIFIED IN PARENTHESES BELOW, ON FILE WITH THE COMMISSION, ARE
     INCORPORATED HEREIN BY REFERENCE AS AN EXHIBIT HERETO, PURSUANT TO
     RULE 7a-29 UNDER THE TRUST INDENTURE ACT OF 1939 (THE ACT) AND
     17 C.F.R. 229.10(d).

     1. A copy of the Organization Certificate of The Bank of New York
        (formerly Irving Trust Company) as now in effect, which contains the
        authority to commence business and a grant of powers to exercise
        corporate trust powers.  (Exhibit 1 to Amendment No. 1 to Form T-1
        filed with Registration Statement No. 33-6215, Exhibits 1a and 1b to
        Form T-1 filed with Registration Statement No. 33-21672 and
        Exhibit 1 to Form T-1 filed with Registration Statement No. 33-29637.)

     4. A copy of the existing By-laws of the Trustee.  (Exhibit 4 to
        Form T-1 filed with Registration Statement No. 33-31019.)

     6. The consent of the Trustee required by Section 321(b) of the Act.
        (Exhibit 6 to Form T-1 filed with Registration Statement No. 33-44051.)

     7. A copy of the latest report of condition of the Trustee published
        pursuant to law or to the requirements of its supervising or examining
        authority.

                                       -2-

<PAGE>


                                     SIGNATURE

Pursuant to the requirements of the Act, the Trustee, The Bank of New York, a
corporation organized and existing under the laws of the State of New York,
has duly caused this statement of eligibility to be signed on its behalf by
the undersigned, thereunto duly authorized, all in The City of New York, and
State of New York, on the 10th day of December, 1999.


                                       THE BANK OF NEW YORK


                                       By: /s/  MICHAEL CULHANE
                                           --------------------
                                           Name:  Michael Culhane
                                           Title: Vice President





<PAGE>


              Consolidated Report of Condition of

                   THE BANK OF NEW YORK
              of One Wall Street, New York, N.Y. 10286
              And Foreign and Domestic Subsidiaries,

a member of the Federal Reserve System, at the close of business September
30, 1999, published in accordance with a call made by the Federal Reserve
Bank of this District pursuant to the provisions of the Federal Reserve Act.

<TABLE>
<CAPTION>
                                                                  Dollar Amounts
                                                                  In Thousands
<S>                                                               <C>
ASSETS
Cash and balances due from depository institutions:
   Noninterest-bearing balances and currency and coin                 $6,394,412
   Interest-bearing balances                                           3,966,749
Securities:
   Held-to-maturity securities                                           805,227
   Available-for-sale securities                                       4,152,260
Federal funds sold and Securities purchased under
   agreements to resell                                                1,449,439
Loans and lease financing receivables:
   Loans and leases, net of unearned income          37,900,739
   LESS: Allowance for loan and
     lease losses                                       572,761
   LESS: Allocated transfer risk reserve                 11,754
   Loans and leases, net of unearned income,
     allowance, and reserve                                           37,316,224
Trading Assets                                                         1,646,634
Premises and fixed assets (including
   capitalized leases)                                                   678,439
Other real estate owned                                                   11,571
Investments in unconsolidated subsidiaries and
   associated companies                                                  183,038
Customers' liability to this bank on acceptances
   outstanding                                                           349,282
Intangible assets                                                        790,558
Other assets                                                           2,498,658
                                                                     -----------
Total assets                                                         $60,242,491
                                                                     ===========
LIABILITIES
Deposits:
   In domestic offices                                               $26,030,231
   Noninterest-bearing                               11,348,986
   Interest-bearing                                  14,681,245
   In foreign offices, Edge and Agreement
     subsidiaries, and IBFs                                           18,530,950
   Noninterest-bearing                                  156,624
   Interest-bearing                                  18,374,326
Federal funds purchased and Securities sold under
   agreements to repurchase                                            2,094,678
Demand notes issued to the U.S.Treasury                                  232,459
Trading liabilities                                                    2,081,462
Other borrowed money:
   With remaining maturity of one year or less                           863,201
   With remaining maturity of more than one year
     through three years                                                     449
   With remaining maturity of more than three years                       31,080
Bank's liability on acceptances executed and
   outstanding                                                           351,286
Subordinated notes and debentures                                      1,308,000
Other liabilities                                                      3,055,031
                                                                     -----------
Total liabilities                                                     54,578,827
                                                                     ===========
EQUITY CAPITAL
Common stock                                                           1,135,284
Surplus                                                                  815,314
Undivided profits and capital reserves                                 3,759,164
Net unrealized holding gains (losses) on
  available-for-sale securities                                          (15,440)
Cumulative foreign currency translation
  adjustments                                                            (30,658)
                                                                     -----------
Total equity capital                                                   5,663,664
                                                                     -----------
Total liabilities and equity capital                                 $60,242,491
                                                                     ===========
</TABLE>

     I, Thomas J. Mastro, Senior Vice President and Comptroller of the
above-named bank do hereby declare that this Report of Condition has been
prepared in conformance with the instructions issued by the Board of Governors
of the Federal Reserve System and is true to the best of my knowledge and
belief.

                                                                Thomas J. Mastro

     We, the undersigned directors, attest to the correctness of this Report
of Condition and declare that it has been examined by us and to the best of
our knowledge and belief has been prepared in conformance with the
instructions issued by the Board of Governors of the Federal Reserve System
and is true and correct.

           Thomas A. Reyni
           Alan R. Griffith             Directors
           Gerald L. Hassell







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