STOCK PURCHASE AGREEMENT

     This Stock Purchase Agreement is made as of June 30, 1996,  pursuant to the
Foundry  Venture  Agreement  which was  entered  into as of July 8, 1995 and the
Amendment to Foundry Venture Agreement and Foundry Capacity  Agreement which was
entered into as of October 31,  1995,  and the letter  agreement  dated June 26,
1996, all by and among the Venturers defined therein and described herebelow, by
and between the Venturers,  referring to Alliance Semiconductor  Corporation,  a
Delaware  corporation  ("Alliance"),  S3  Incorporated,  a Delaware  corporation
("S3"), and United Microelectronics  Corporation,  a corporation organized under
the laws of the Republic of China ("UMC"), and United Semiconductor  Corporation
("USC"), the corporation contemplated under and referred to as FabCo in the said
Foundry Venture Agreement.

         Venturers and USC agree:

1.      PURCHASE AND SALE OF STOCK

     1.1  Venturers  hereby agree to purchase  from USC and USC hereby agrees to
issue and sell to Venturers its stocks at par value New Taiwan  Dollars Ten (NT$
10) each  share.  All  stocks  issued  and sold by USC  pursuant  to this  Stock
Purchase Agreement shall be common stocks.



     1.2 Pursuant to the Foundry Venture  Agreement,  the total number of common
stock USC  issues  and  sells  under  the laws of the  Republic  of China is One
Billion  (1,000,000,000)  shares.  Each  Venturer  shall  purchase the number of
shares according to the following table (assuming full exercise of the option to
purchase under Paragraph 5. 1 (b)):


                                                                 $ investment represented
                                      Share % paid in cash          by standard shares 
                                       ("Standard Shares")            (NTD Billions)              Technical share %
                                       -------------------            --------------              -----------------
                                                                                              
Alliance                                     18.99%                       $1.9 B                         0%
S3                                           23.75%                       $2.4 B                         0%
UMC & UMC Affiliates*                        39.76%                       $3.95B                        15%
USC & UMC employees**                         2.5%**                      $0.25B                         0%
Total shareholding                           85%                          $8.5 B                        15%

<FN>

* For purposes of this Stock Purchase  Agreement,  "UMC  Affiliates"  shall mean
those  entities:  (i) nominated by UMC and approved by the Venturers in writing,
(ii) which UMC directly and/or  indirectly  controls,  and/or (iii) in which UMC
directly or indirectly owns a majority interest;  provided that no UMC Affiliate
which is a competitor  of S3 and/or  Alliance may hold shares in USC pursuant to
rights granted to UMC Affiliates under this Stock Purchase Agreement without the
prior written consent of the Venturer involved. In addition, UMC may transfer up
to 5% of USC's standard  shares to UMC employees  and/or to employees of USC for
purposes of providing  additional  incentives  in  connection  with USC business
without necessity for any prior written consent from USC or from any Venturer. 

* * UMC employees who intend to become (and who later become) regular  employees
of USC  will be among  the USC  shareholders  pursuant  to this  table.  The UMC
employees and the eligible USC  employees  shall be required to pay in cash upon
issuance the value shown in this table for their standard shares.

</FN>


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     1.3 The Venturers  shall pay in cash for their standard shares in two equal
funding  installments,  and each Venturer represents to the other Venturers that
the amount indicated in the column titled "First  Installment" has been paid and
USC acknowledges receipt of such amounts:


                                                       First Installment            Second Installment -due in full
                                                        (paid as shown)                on or before July 4, 1996 
                                                        (NTD billions)                       (NTD billions)
                                                        --------------                       --------------
                                                                                             
Alliance                                                    $1   B                              $0.45B
S3                                                          $1   B                              $0.7 B
UMC & UMC Affiliates                                        $2.25B                              $2.85B
USC employees & UMC employees                               $0   B                              $0.25B
Total payment for standard shares                           $4.25B                              $4.25B

                                                                      

    1.4 Within  fifteen days of receiving a signature  version of such a voting
agreement,  S3 will execute a voting agreement concerning 5% ownership of USC in
the form as  signed by China  Trust  Group  and the  other  Taiwan  institutions
approved by S3 and Alliance for participation in USC.

     1.5 The  technical  shares shall be issued in  accordance  with the Foundry
Venture Agreement.


2.      REPRESENTATIONS OF USC

     2.1 USC represents and warrants, which representations and warranties shall
survive the purchase date, that:

          (i) USC has been duly formed and is in  existence  and has operated in
conformity with all laws and regulations applicable to its operation;

          (ii) The issuance of the shares of common stock contemplated herein is
in conformance  with all laws and regulations  applicable to the issuance of the
shares;

          (iii)  Attached   hereto  is  the  true  copy  of  USC's  Articles  of
Incorporation; and

          (iv) USC has duly  authorized  the sale and  issuance of the shares to
the Venturers.



                                       18



3.       BOARD OF DIRECTORS AND SUPERVISORS

     3.1 USC will have at least seven (7)  directors on its board of  directors,
of which at least  five (5)  directors  shall be  designated  by UMC  and/or UMC
Affiliates, and each of Alliance and S3 shall designate one (1) director.

     3.2 USC will have at least two (2)  supervisors,  of which at least one (1)
supervisor shall be designated by Alliance and S3.

     3.3  Notwithstanding  anything  to the  contrary,   (i) all such  directors
and/or  supervisors  shall be subject to the requirements of applicable law, and
(ii) the rights to designate  directors  and/or  supervisors will expire if (for
reasons  other than a failure  of  conditions  precedent  to such  payment)  the
Venturer fails to make timely  payment of its second  installment of the funding
outlined in Paragraph 1.3 above.

     3.4 The following  decisions shall be made only by resolutions of the board
of directors  requiring an attendance of all the directors and an unanimous vote
of all of the directors, and are not within the authority of the chairman. These
decisions are as follows:

          (i)  All  actions  directly   deciding   strategic   technical  issues
(including without limitation, the type of process technology, such as that used
in the manufacture of logic,  SRAM,  DRAM,  EPROM,  EEPROM,  and/or FLASH) to be
developed, implemented and/or offered by USC;

          (ii) All actions  directly making  material  changes to the technology
road map as approved by the board and/or authorizing  liquidation,  merger, sale
of all or  substantially  all of USC or USC's  assets,  and/or  the offer of any
equity  (except  pursuant to a public  offering of USC's  shares on a recognized
securities exchange); and

     3.5 The  Venturers  each  commit to vote their  shares in a manner so as to
implement this Paragraph 3.

     3.6 This  Paragraph  3 shall  expire  and have no further  effect  upon the
successful  completion  of a public  offering  of USC's  shares on a  recognized
securities exchange.

     3.7 The  Venturers  and USC have held a  shareholders'  meeting and thereby
amended the articles of  incorporation  of USC to reflect the provisions of this
Paragraph 3.


4.       DELIVERY OF FINANCIAL STATEMENTS; AUDIT RIGHTS

     4.1 USC shall deliver to each Venturer:

          (i) as soon as practicable,  but in any event within 60 days after the
end of each fiscal year of USC, (A) a statement of  operations  and statement of
cash  flows of USC for such  year,  and a balance  sheet of USC as of the end of
such year, such year-end financial reports to be in reasonable detail,  prepared
in accordance  with generally  accepted  accounting  principles  ("GAAP") of the
Republic of China  ("ROC"),  accompanied by a  reconciliation  of such financial
statements  to  United  States  ("US")  GAAP,   and  audited  and  certified  by
independent public accountants of internationally  recognized  standing selected
by USC, and (B) a management discussion and analysis, certified by the President
or Chief  Financial  Officer  of USC,  explaining  material  variations  in such
financial statements from USC's business plan;

          (ii)  within 15 days  after  the end of each  Venturer's  fiscal  year
(March  31 for  Alliance,  December  31  for  S3),  an  unaudited  statement  of
operations  and balance  sheet for and as of USC's most  recent  fiscal year (or
interim period thereof), together with such other financial information as shall
be reasonably  requested by such Venturer in connection  with the preparation of
such  Venturer's  annual  earnings  release,  including  a  statement  of  USC's
independent  public  accounting firm indicating that on the basis of a review of
such financial statements nothing



                                       19


has come to the attention of such  accountants  that such  financial  statements
have not been  prepared  in  accordance  with ROC GAAP on a basis  substantially
consistent  with  USC's  audited  financial  statements  or  that  any  material
modifications  should be made to the unaudited  statement of operations for them
to be stated on a basis  substantially  consistent with USC's audited  financial
statements;

          (iii)  within  30  days  after  the  end of each  fiscal  quarter,  an
unaudited statement of operations, statement of cash flows and balance sheet for
and  as of the  end of  such  quarter,  in  reasonable  detail;  such  quarterly
statements shall also contain the foregoing information on a year-to-date basis,
be prepared in accordance  with ROC GAAP, and include a  reconciliation  of such
financial statement to US GAAP;

          (iv) within 10 days after the end of each fiscal quarter, an unaudited
statement of operations and balance sheet for and as of the end of such quarter,
in reasonable detail,  together with such other financial information,  as shall
be reasonably  requested by such Venturer in connection  with the preparation of
such Venturer's quarterly earnings release, such quarterly statements shall also
contain  the  foregoing  information  on a  year-to-date  basis,  be prepared in
accordance  with ROC  GAAP,  and  include  a  reconciliation  of such  financial
statements to US GAAP;

          (v) within 30 days after the end of each month, an unaudited statement
of  operations,  statement of cash flows and balance sheet for and as of the end
of such month, in reasonable detail,  such monthly statements shall also contain
the foregoing  information  on a year-to-date  basis,  shall also compare actual
performance to budget, and be prepared in accordance with ROC GAAP;

          (vi)  within  60 days  prior  to the  close  of each  fiscal  year,  a
comprehensive operating budget for the next fiscal year forecast USC's revenues,
expenses  and cash  position,  prepared on a monthly  basis,  including  balance
sheets and sources and  applications of funds statements for such months and, as
soon as prepared, any other budgets or revised budgets prepared by USC; and

          (vii)  such  other  financial  information  relating  to USC  as  such
Venturer may from time to time reasonably request,  provided,  however, that USC
shall not be obligated to provide  information  pursuant to this  Paragraph 4. 1
(vii) which it deems in good faith to be proprietary.

     4.2 With  respect to the  financial  statements  called for in  subsections
(ii),  (iii),  (iv) and (v) of  Paragraph  4.1,  an  instrument  executed by the
President or Chief  Financial  Officer of USC and certifying that such financial
statements  were prepared in accordance with  internally  consistent  accounting
methods  consistently applied with prior practice for earlier periods and fairly
present the  financial  condition  of USC and its results of  operation  for the
period specified, subject to year-end audit adjustment.

     4.3  Upon  the  written  request  of a  Venturer,  USC  shall  permit  such
Venturer's  independent  certified  public  accounting  firm, at such Venturer's
expense,  to have  access  during  normal  business  hours of USC to such of the
records  of USC  and of  USC's  independent  public  accounting  firm  as may be
reasonably  necessary  to  audit  USC's  financial  statements  and  records  in
connection with the preparation of such Venturer's audited financial statements.

5.       SHARE TRANSFER

     5.1 Notwithstanding anything to the contrary,

     (a) the shares of UMC and UMC Affiliates shall be transferable  amongst UMC
and UMC Affiliates without the necessity of USC's,  Alliance's and/or S3's prior
written consent.

     (b) Notwithstanding  anything to the contrary, and without any need for any
further  consents from any Venturer or from USC,  under the terms stated in this
Paragraph  5. I (b),  S3 will  have the  option  to  purchase  from


                                       20


UMC up to 70 Million  standard  shares of USC, and Alliance will have the option
to purchase from UMC up to 45 Million standard shares of USC as follows:

          (i) The  purchase  price  under  these  options  will be at NTD 10 per
share,  plus  interest  on the total  purchase  amount.  This  interest  will be
calculated at a cumulative  rate of 8.5%,  with interest  accruing as of July 4,
1996.

          (ii) Each of S3 and Alliance may exercise  these options with at least
fifteen days advance  written notice to the other  Venturers  given prior to the
end of calendar year 1996, but all unexercised  options will expire if not fully
exercised  (including full payment to UMC for the shares  involved) on or before
midnight December 31, 1996 (Taiwan, R.O.C. time).

          (iii) Subject to the terms of this Agreement,  each of Alliance and S3
can exercise its respective  options all at once, or in installments,  and thus,
with at least  fifteen days advance  written  notice to the other  Venturers can
select its closing dates (so long as they occur on or before the end of December
31, 1996) at times it finds convenient.

     5.2 Except as allowed under Paragraph 5.1, until USC completes a successful
offering  of shares  on a  recognized  securities  exchange,  the  shares of the
Venturers  (and of UMC  Affiliates  holding  such  shares)  in USC  will  not be
transferable  in any manner  whatsoever  except with the written  consent of the
Venturers,  provided  however that any  Venturer may transfer its entire  right,
title and interest in USC  (including its  proportionate  right of first refusal
for foundry  capacity,  the "Foundry Rights") and other rights under the Foundry
Venture  Agreement and/or Venture  Agreements (as defined in the Foundry Venture
Agreement):

          (i) once but only to the extent and only as part of a transfer  of all
or substantially  all of the assets,  business and/or ownership of that Venturer
to a transferee  subject,  with respect to the Foundry  Rights,  to the terms of
Paragraph 5.2 (iv) below;

          (ii) as  provided  in  Paragraphs  6.3 and/or 6.4 of the said  Foundry
Venture Agreement, and/or

          (iii) once to or between itself and any of its  subsidiaries in which,
at the time of such transfer, the transferring Venturer owns at least 50%.

Notwithstanding anything to the contrary:

          (iv)the  Foundry Rights when and if transferred  pursuant to Paragraph
5.2 (i) above  shall only be  exercisable  with  respect to the  manufacture  of
products  which  the  transferring  Venturer  at the time of such  transfer  was
selling,  was  designing  (as  reflected in  contemporaneous  documents)  or was
contemplating  designing  and  selling  (as  demonstrated  in its  then  written
business plan(s)),  and all future versions and logical extensions of such types
of products  (including  without  limitation,  more highly  integrated  versions
thereof).

          (v) if (a)  prior  to  the  completion  of a  public  offering  of USC
securities on a recognized  securities exchange,  any Venturer (or UMC Affiliate
holding such shares) wishes and/or attempts to transfer its shares in USC (other
than as allowed by Paragraphs  5.1, 5.2 (i), 5.2 (ii) and/or 5.2 (iii)) pursuant
to any Court or other order or law, or as a result of any  nonconsensual  action
by any authority with jurisdiction,  and/or (b) a Venturer's rights are properly
terminated pursuant to Section 6.1 of the Foundry Venture Agreement,  the shares
involved will be subject to a right of first refusal as follows:

               (aa) the other  Venturers (the "eligible other  Venturers")  will
have the right to purchase  the shares  involved at their then fair market value
as determined by a mutually agreeable independent appraiser;

                                       21


               (bb) each such  eligible  other  Venturer  will have the right to
purchase  such  shares on a pro rata basis as  determined  by the ratio of their
respective  shareholding  percentages  (which,  absent any previously  permitted
transfers, would be as shown in the table in Paragraph 1.2 above);

               (cc) if any such eligible other  Venturer  elects not to exercise
any  portion  or all of  such  right  of  first  refusal  within  30 days of the
independent  appraisal,  such  portion  of such right of first  refusal  will be
subject  to  exercise  by the other  eligible  other  Venturer,  and the  shares
involved  will be subject to a right of such other  eligible  other  Venturer to
purchase on the same terms as outlined above; and

               (dd) if the other  eligible  other  Venturer  does not  commit to
purchase such shares  within 60 days of the  independent  appraisal,  all rights
under this Paragraph 5.2 (v) will expire as to such unpurchased shares.

     5.3  Subject to the  requirements  of and to the extent  permissible  under
R.O.C. law, to the extent that USC wishes to offer any (equity beyond the NT$8.5
Billion  referred to in Paragraph 1.2 (a) above,  each  Venturer  shall have the
right of first refusal to participate in such offering in proportion to its then
current respective shareholding.

6.       MISCELLANEOUS

     6.1 Governing Law. This Agreement shall be construed in accordance with and
governed by the laws of the Republic of China.

     6.2   Counterparts.   This  Agreement  may  be  executed  in  two  or  more
counterparts,  each of  which  shall be  deemed  an  original,  but all of which
together shall constitute one and the same instrument.

     6.3 Paragraphs 7, 8, 9.1, 9.2, 9.3, 9.4, 9.5, 9.7, 9.8, 9.10,  9.11,  9.13,
and 9.14 of the Foundry  Venture  Agreement are  incorporated by reference as if
set forth fully herein,  in each case with this Stock Purchase  Agreement deemed
to be one of the Venture Agreement.




                                       22



     IN WITNESS  WHEREOF,  the Venturers and USC have caused this Stock Purchase
Agreement to be signed below by their respective duly authorized officers.

Alliance Semiconductor Corporation

/s/ N. D. Reddy
- -----------------------------
N. D. Reddy, President


S3 Incorporated

/s/ Terry Holdt
- -----------------------------
Terry Holdt, President


United Microelectronics Corporation

/s/ John Hsuan
- -----------------------------
John Hsuan, President


United Semiconductor Corporation

/s/ Ing Dar Liu
- -----------------------------
Ing Dar Liu, President



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