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                                                                  EXHIBIT 10.1


                               OPTION AGREEMENT I

                                    Between

                      Adaptec Manufacturing (S) Pte. Ltd.

                                      And

                  Taiwan Semiconductor Manufacturing Co., Ltd.

                                October 23, 1995
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                               TABLE OF CONTENTS

1.      DEFINITIONS                                             1

2.      VOLUME CAPACITY                                         2

3.      WAFER PRICE                                             3

4.      OTHER PURCHASE TERMS AND CONDITIONS                     3

5.      OBLIGATION TO PAY OPTION FEE FOR OPTION CAPACITY        3

6.      FAILURE TO PURCHASE THE OPTION CAPACITY;                4
        FIRST RIGHT OF REFUSAL

7.      TERM AND TERMINATION                                    4

8.      BOARD APPROVAL                                          5

9.      LIMITATION OF LIABILITY                                 5

10.     NOTICE                                                  5

11.     ENTIRE AGREEMENT                                        6

12.     GOVERNING LAW                                           6

13.     ARBITRATION                                             6

14.     ASSIGNMENT                                              7

15.     CONFIDENTIALITY                                         7

16.     FORCE MAJEURE                                           7

17.     NO AGENCY                                               7

18.     GOVERNMENTAL APPROVAL                                   7

19.     COUNTERPARTS                                            8

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                               OPTION AGREEMENT I

        THIS AGREEMENT is made and becomes effective as of October 23, 1995 
(the "Effective Date") by Taiwan Semiconductor Manufacturing Co., Ltd. 
("TSMC"), a company organized under the laws of the Republic of China with its 
registered address at No. 121, Park Ave. 3, Science Based Industrial Park, 
Hsinchu, Taiwan and Adaptec Manufacturing (S) Pte. Ltd., a company organized 
under the laws of Singapore, with its registered address at 6 Battery Road, 
532-00, Singapore 049909 ("Customer").

RECITALS

        WHEREAS, TSMC currently supplies Customer with wafers and Customer 
wishes to increase the volume of wafers to be purchased from TSMC;

        WHEREAS, in order to increase its output, TSMC must accelerate its ramp 
up in Fab 3 and advance the start of Fab 4;

        WHEREAS, as a condition to TSMC's acceleration of these facilities, 
TSMC has asked that Customer make a capacity commitment and advance payment for 
the right to buy additional capacity, and Customer is willing to do so:

AGREEMENT

        NOW, THEREFORE, in consideration of the mutual covenants and conditions 
contained herein, the parties agree as follows:

1.      DEFINITIONS

        (a)     "Base Capacity" used in this Agreement shall mean the 
                annualized run rate that TSMC commits to provide the Customer 
                as set forth in Exhibit B.

        (b)     "Customer Committed Capacity" used in this Agreement shall mean 
                the total capacity that Customer agrees to purchase from TSMC 
                pursuant to this Agreement, either itself or by an Affiliate, 
                and as set forth in Exhibit B.

        (c)     "Foundry Agreement" used in this Agreement shall mean the 
                Foundry Agreement between TSMC and Adaptec, Inc., dated 
                October 29, 1993, together with any amendments thereto.

        (d)     "Option Capacity" used in this Agreement shall mean the firm 
                capacity commitment made by Customer pursuant to this 
                Agreement, for which               

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                capacity Customer agrees to pay the Option Fee as defined in 
                Section 1(e) below.

        (e)     "Option Fee" used in this Agreement shall mean the deposit that 
                Customer agrees to place with TSMC as the advance payment for 
                the wafers comprising the Option Capacity.

        (f)     "TSMC Committed Capacity" used in this Agreement shall mean the 
                total capacity that TSMC agrees to provide to Customer or its 
                Affiliates, consisting of Base Capacity and Option Capacity as 
                set forth in Exhibit B.

        (g)     "Wager Equivalent" used in this Agreement shall mean the number 
                of six-inch wafers, adjusted by the equivalency factor based 
                on 1996 Base Capacity as set forth on Exhibit A, by which 
                capacity commitments are measured hereunder. An example of 
                such calculation is set forth on Exhibit B-1. Any and all 
                capacity commitments referred to in this Agreement shall be 
                for the calender year and measured in Wafer Equivalents.


        (h)     "Affiliates" used in this Agreement shall mean a party which 
                holds at least a seventy-five percent (75%) ownership interest 
                in Customer or a party in which Customer's parent holds at 
                least a seventy-five percent (75%) ownership interest.

2.      VOLUME COMMITMENT       

        (a)     Customer agrees to purchase annually form TSMC, either itself 
                or through its Affiliates, the Customer Committed Capacity set 
                forth for such year on Exhibit B and, subject to the payment 
                of the Option Fee by Customer under Section 5 below, TSMC 
                agrees to provide to Customer the TSMC Committed Capacity, 
                as set forth in Exhibit B. In any calender year, the orders 
                placed by Customer or its Affiliates shall first apply to 
                fulfill the Base Capacity portion of the Customer Committed 
                Capacity, and then the Option Capacity portion.

        (b)     Each month, Customer agrees to provide to TSMC a six-month
                rolling forecast of the number of wafers that Customer will
                purchase, with the volume for the first twelve weeks being
                frozen (i.e., Customer must purchase all of the quantity
                forecast for the delivery in the first twelve weeks of the
                forecast). The forecast must be based on wafers out.

        (c)     TSMC will use its best efforts to cause its fabs to be capable 
                of producing wafers of more advanced specifications, as set
                forth in the TSMC Technology Road Map attached to Exhibit C.
                (The parties anticipate that the conversion factor for migration
                of 6" to 8" inch wafers will 1.78.)

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3.      WAFER PRICE

        (a)     The prices for wafers purchased by Customer during the term of
                this Agreement shall not be more than TSMC's average wafer
                prices to the optionees (i.e., other customers that are parties
                to option agreements similar to this Agreement) for the same
                technology, the same fab and the same period of time, taking
                into account Customer's total volume across all TSMC fabs. At
                Customer's request, TSMC shall permit an independent third party
                mutually agreed upon by the parties to audit such books and
                records as may be required to verify TSMC's most favored
                customer pricing obligations in the preceding sentence. Such
                audits shall be at Customer's expense at any time during the
                term of this Agreement upon at least one (1) month prior written
                notice to TSMC. In the event that the wafer prices do not comply
                with the first sentence, TSMC will make proper price changes for
                all unfilled orders upon Customer's notice in writing.

        (b)     The parties shall negotiate in good faith each year the wafer
                prices for the Option Capacity of the following year, and if no
                agreement is reached by the parties before October of each year
                for the succeeding calendar year, the parties agree to submit
                the dispute to the binding arbitration pursuant to Section 13
                below, and under such circumstances, neither party shall have
                the right to terminate this Agreement under Section 7 below.

4.      OTHER PURCHASE TERMS AND CONDITIONS

        The Foundry Agreement, together with any amendments thereto, will apply
        to all purchases of wafers by Customer from TSMC, except that the
        provisions of this Agreement will supersede the Foundry Agreement with
        respect to the subject matter hereof.

5.      OBLIGATION TO PAY OPTION FEE FOR OPTION CAPACITY

        (a)     Customer agrees to pay to TSMC the Option Fee in the amount of
                [****] per Wafer Equivalent for the right to purchase the Option
                Capacity pursuant to this Agreement. The Option Fee is set forth
                in Exhibit D, and Customer agrees to pay the Option Fee for the
                entire term of this Agreement $19.6M in cash by November 15,
                1995. The Option Fee, once paid, shall be non-refundable, except
                as provided in Section 6(a) and Section 7(d), and will be
                credited against payments due for wafers purchased by Customer
                for the Option Capacity provided by TSMC under this Agreement.

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6.      FAILURE TO PURCHASE THE OPTION CAPACITY; FIRST RIGHT OF REFUSAL

        If, in any calendar year, for any reason, Customer is not able to use or
        purchase all or a portion of the Customer Committed Capacity for that
        year, Customer shall promptly notify TSMC of such in writing and first
        offer TSMC such capacity for sales to any third parties. TSMC may, at
        its option, accept such offer, in whole or in part, within thirty (30)
        days following Customer's notification and, if TSMC so accepts, the
        Option Fee attributable to that capacity will be refunded to Customer
        without interest. In the event that TSMC decides not to accept such
        offer, Customer may sell such unused capacity to third parties
        reasonably acceptable to TSMC (given the processes and capacity then
        available in its fabs), within two months after TSMC's written notice
        that it will not accept such offer. If Customer fails to sell such
        unused Customer Committed Capacity, TSMC shall not be required to refund
        any portion of the unapplied Option Fee applicable to that unused
        capacity. TSMC is entitled to sell or use any such capacity thereafter.
        Forfeiture of the applicable Option Fee shall be TSMC's sole remedy for
        Customer's failure to purchase the Customer Committed Capacity in any
        calendar year.

7.      TERM AND TERMINATION

        (a)     TERM

                The term of this Agreement shall commence from the Effective 
                Date, and continue until December 31, 1999.

        (b)     TERMINATION BY TSMC FOR CUSTOMER'S FAILURE TO PAY THE OPTION FEE

                TSMC may terminate this Agreement if Customer fails to pay the
                Option Fee pursuant to Section 5 above, and does not cure or
                remedy such breach within thirty (30) days of receiving written
                notice of such breach.

        (c)     TERMINATION FOR OTHER BREACH OR FOR BANKRUPTCY

                Either party may terminate this Agreement if, (i) the other
                party breaches any material provisions of this Agreement (other
                than Customer's breach of Section 5 above), and does not cure or
                remedy such breach within one hundred and twenty (120) days of
                receiving written notice of such breach, or (ii) becomes the
                subject of a voluntary or involuntary petition in bankruptcy or
                any proceeding relating to insolvency, receivership or
                liquidation, if such petition or proceeding is not dismissed
                with prejudice within sixty (60) days after filing.

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        (d)     EFFECT OF TERMINATION

                In the event of termination of this Agreement, each party shall
                remain liable to the other party for any outstanding and matured
                rights and obligations at the time of termination, including
                payment of the Option Fee applicable to the used Option Capacity
                and for the wafers already ordered and shipped to Customer. Any
                wafers then in process pursuant to a Customer order may be
                completed and shipped to Customer and the applicable Option Fee
                amount applied against such wafers. In the event Customer
                terminates this Agreement pursuant to the terms of Section 7(c),
                any portion of the Option Fee then remaining, which has not been
                applied against purchases of wafers, will be refunded to
                Customer within thirty (30) days of termination of this
                Agreement.

8.      BOARD APPROVAL

        Customer shall obtain the approval by its board of directors of this
        Agreement, and submit to TSMC, at the time of executing this Agreement,
        an authentic copy of its board resolution authorizing the representative
        designated below to execute this Agreement.

9.      LIMITATION OF LIABILITY

        In no event shall either party be liable for any indirect, special,
        incidental or consequential damages (including loss of profits or loss
        of use) resulting from, arising out of or in connection with such
        party's performance or failure to perform under this Agreement, or
        resulting from, arising out of or in connection with the production,
        supply and/or purchase and sale of the wafers, whether due to a breach
        of contract, breach of warranty, tort, or negligence of such party, or
        otherwise.

10.     NOTICE

        All notices required or permitted to be sent by either party to the
        other party under this Agreement shall be sent by registered mail
        prepaid, or by personal delivery, or by fax. Any notice given by fax
        shall be followed by a confirmation copy within ten (10) days. Unless
        changed by written notice given by either party to the other, the
        addresses and fax numbers of the respective parties shall be as follows:

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        To TSMC:

        TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
        No. 121, Park Avenue 3
        Science-Based Industrial Park
        Hsinchu, Taiwan
        Republic of China                       FAX: 886-35-781545

        To Customer:

        ADAPTEC MANUFACTURING (S) PTE. LTD.
        Block 1001
        Jalan Bukit Merah #07/01-20
        Singapore 0315

        With a copy to:

        ADAPTEC, INC.
        Attention:  Vice President, Procurement
        691 South Milpitas Boulevard
        Milpitas, California 95035              FAX: (408) 262-2533

11.     ENTIRE AGREEMENT

        This Agreement, including Exhibits A-D, and together with the Foundry
        Agreement, constitutes the entire Agreement between the parties with
        respect to the subject matter hereof, and supersedes and replaces all
        prior to contemporaneous understandings, agreements, dealings and
        negotiations, oral or written, regarding the subject matter hereof. No
        modification, alteration or amendment of this Agreement shall be
        effective unless in writing and signed by both parties. No waiver of any
        breach or failure by either party to enforce any provision of this
        Agreement shall be deemed a waiver of any other or subsequent breach, or
        a waiver of future enforcement of that or any other provision.

12.     GOVERNING LAW

        This Agreement will be governed by and interpreted in accordance with
        the laws of the State of California.

13.     ARBITRATION

        Each party will use its best efforts to resolve amicably any disputes or
        claims under this Agreement between the parties. In the event that a
        resolution is not reached among the parties within thirty (30) days
        after written notice by any party of the 

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        dispute or claim, the dispute or claim shall be finally settled by
        binding arbitration in the San Francisco Bay Area, California under
        the Rules of Commercial Arbitration of the American Arbitration
        Association by three (3) arbitrators appointed in accordance with such
        rules. The arbitration proceeding shall be conducted in English.
        Judgment on the award rendered by the arbitrator may be entered in any
        court having jurisdiction thereof.

14.     ASSIGNMENT

        This Agreement shall be binding on and inure to the benefit of each 
        party and its permitted successors and assigns. Customer may assign its
        purchase rights and obligations under this Agreement (a) to third
        parties in accordance with Section 6 above, and (b) to its Affiliates.
        Except as provided in Section 6, neither party shall assign any of its
        rights hereunder, nor delegate its obligations hereunder, to any third
        party, without the prior written consent of the other.

15.     CONFIDENTIALITY

        Neither party shall disclose the existence or contents of this Agreement
        except as required by Customer's assignment of this Agreement to any 
        third parties pursuant to Sections 6 and 14 above, in confidence to its
        advisors, as required by applicable law, or otherwise with the prior
        written consent of the other party.

16.     FORCE MAJEURE

        Neither party shall be responsible for delays or failure in 
        performance resulting from acts beyond the reasonable control of such
        party. Such acts shall include but not be limited to acts of God, war,
        riot, labor stoppages, governmental actions, fires, floods, and
        earthquakes. If such delays or failures on the party of either party
        continue for a period of more than one hundred twenty (120) days, the
        other party may terminate this Agreement upon written notice, subject
        to Section 7(d).

17.     NO AGENCY

        No agency, partnership, joint venture, teaming agreement or other joint
        relationship is created hereby and neither party, nor any of its agents
        or representatives, has any authority of any kind to bind the other
        party in any respect whatsoever.

18.     GOVERNMENTAL APPROVAL

        TSMC represents and warrants to Customer that no governmental approval 
        or registration by or with the ROC is required for this Agreement or
        for the transactions contemplated hereby. In the event any such
        approval or registration is required, TSMC agrees to indemnify and hold
        Customer

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        harmless from any and all loss or damage to Customer which may result
        from the failure to procure such approval or effect such registration.

19.     COUNTERPARTS

        This Agreement may be executed in two counterparts, together which will 
        constitute a fully executed Agreement.

        IN WITNESS WHEREOF, the parties, have executed this Agreement as of the 
Effective Date by their duly authorized representatives.

 TAIWAN SEMICONDUCTOR                       ADAPTEC MANUFACTURING
MANUFACTURING CO., LTD.                          (S) PTE. LTD.


By: /s/ DONALD BROOKS                        By: /s/ SAM KAZARIAN
   ------------------                           ------------------
      Donald Brooks                                Sam Kazarian
      President                                    Director and Attorney-In-Fact

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                                   Exhibit A
                             CAPACITY FACTOR TABLE

                               Masking       W-Plug      Complexity    Capacity
Generic Technology            Layers(A)     Layers(B)     Index(C)     Factor(D)
                             (w/o ESD or
                              Polyimide)
                
1.5um SPDM (BiCMOS)              16                          16          1.23
1.2um SPDM (Logic)               13                          13          1.00
1.0um SPDM (Logic)               13                          13          1.00
1.0um DPDM (BiCMOS)              18                          18          1.38
0.8um SPDM (Logic)               13                          13          1.00
0.8um DPDM (MixMode)             14                          14          1.08
0.8um SPTM (Logic Salicide)      17                          17          1.31
0.8um DPDM (BiCMOS)              22                          22          1.69
0.6um SPDM (Logic)               14            1            14.5         1.12
0.6um SPTM (Logic)               16            1            16.5         1.27
0.6um DPDM (MixMode)             15            1            15.5         1.19
0.6um DPDM (SRAM)                20                          20          1.54
0.6um TPSM (DRAM)                15            1            15.5         1.19
0.6um QPDM (DRAM)                18            1            18.5         1.42
0.5um SPDM (Logic)               14            2             15          1.15
0.5um SPTM (Logic SACVD)         16            3            17.5         1.35
0.5um SPTM (Logic-CMP)           21            3            22.5         1.73
0.5um DPDM (SRAM)                20            1            20.5         1.58
0.5um QPDM (DRAM)                21            1            21.5         1.65
0.35um SPTM (Logic-CMP)          21            3            22.5         1.73

Remarks:   (1) Masking Layer of w/i ESD (or Polyimide) = Masking Layer of w/o
               ESD (or Polyimide) + 1
           (2) Masking Layer of Mixed-Mode(DP) = Masking Layer of Logic(SP) + 1
           (3) Complexity Index (C) = (A) + (B) / 2
           (4) Capacity Factor (D) = (C) / 13, normalized to 0.8um SPDM as 1

Date of issue: 6/9/95
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                                   EXHIBIT B
                        CUSTOMER/TSMC COMMITTED CAPACITY

                                                     Unit: K 6" Wafer Equivalent




                        1996    1997    1998    1999    2000
                        ----    ----    ----    ----    ----
                                         
Take or Pay              *       *
Capacity                 

Base Capacity            *       *       *       *       *
(For Options)

X% of Base              90%     80%     70%     60%     50%
Capacity

Option I                 *       *       *       *
Capacity

Option II                        *       *       *       *
Capacity

TSMC Committed           *       *       *       *       *
Capacity (Base
Capacity + Option
Capacity)

Customer Committed       *       *       *       *       *
Capacity (X% Base
Capacity + Option
Capacity)


Deposits Required:

        Option I   -    At contract signing  $19.6M

        Option II  -    June 30, 1996        $46.2M


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                                 Exhibit B1
                        WAFER EQUIVALENT CALCULATION

TO CALCULATE THE WEIGHTED CAPACITY FACTOR




                                                                                               WEIGHTED
                                         CAPACITY           WAFER          PERCENTAGE          CAPACITY
PROCESS                                   FACTOR          CAPACITY         OF VOLUME            FACTOR
                                                                                   

 .8um SPDM                                   *                *                 *                   *

 .6um SPTM                                   *                *                 *                   *

TOTAL VOLUME                                *                *                 *                   *

1996 WEIGHTED CAPACITY FACTOR                                                                      *

 .6um SPTM                                   *                *                 *                   *

TOTAL VOLUME                                                 *                 *                   *

1997 WEIGHTED CAPACITY FACTOR                                                                      *

TO CALCULATE THE EQUIVALENT CAPACITY

1997 COMMITTED CAPACITY                                                        *

1997 EQUIVALENT CAPACITY                   ***                                 *


1997 EQUIVALENT CAPACITY = (1996 WEIGHTED CAPACITY FACTOR/1997 WEIGHTED
                           CAPACITY FACTOR) * 1997 COMMITTED CAPACITY
   
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                                   Exhibit C
                            TSMC TECHNOLOGY ROAD MAP


                          TSMC CMOS Technology Roadmap


MIXED                   0.6um           0.5um           0.35um
MODE                    2P3M            2P3M            2P4M
                                                        3V
                                         3V


LOGIC                   0.6um           0.5um           0.35um
                        1P3M            1P3M            1P4M
                                                        3V
                                           1P3M
                                            3V

SRAM                0.6um     0.5um    0.45um     0.35um
                                                    3V
                                3V       3V                   


                        Q1 Q2 Q3 Q4
                             *          *          *         *         *

                        

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                                   EXHIBIT D
                             OPTION FEE (OPTION I)


   Year         Option Capacity         Option Fee              Due Date
Established      (Unit: Wafer           (Unit: US$)     
                  Equivalent)

   1995                *                   $19.6M           November 15, 1995





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