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                                                              EXHIBIT 10(iii)(A)


                                                   As Amended Effective 10-26-99


                        DALLAS SEMICONDUCTOR CORPORATION

                         AMENDED 1987 STOCK OPTION PLAN


     1. Purpose. The Dallas Semiconductor Corporation 1987 Stock Option Plan
(the "Plan") is intended to advance the interests of Dallas Semiconductor
Corporation, a Delaware corporation (the "Company"), and its stockholders, by
encouraging and enabling selected officers, directors, consultants, agents and
employees, upon whose judgment, initiative and effort the Company is largely
dependent for the successful conduct of its business, to acquire and retain a
proprietary interest in the Company by ownership of its stock. It is intended
that options which may qualify for treatment as "incentive stock options" under
Section 422A of the Internal Revenue Code of 1986, as amended, and applicable
regulations and rulings promulgated thereunder (collectively the "Code"), as
well as options which may not so qualify, may be granted under the Plan.

     2. Definitions.

          (1) "Board" means the Board of Directors of the Company or a Committee
     of the Board to whom its authority has been delegated.

          (2) "Common Stock" means the Company's Common Stock, $.02 par value
     per share.



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          (3) "Date of Grant" means the date on which an Option is granted under
     the Plan, which will be the date the Board authorizes the Option unless the
     Board specifies a later date.

          (4) "Date of Exercise" means the date on which an Option is validly
     exercised pursuant to the Plan.

          (5) "Exchange Act" means the Securities Exchange Act of 1934, as
     amended.

          (6) "Fair Market Value" of the Company's Common Stock means, as long
     as the Company's Common Stock is traded on the New York Stock Exchange, the
     closing price of such stock on the New York Stock Exchange on such date (or
     if such date is not a trading day, on the last trading day immediately
     preceding such date) or, if not so traded, on the NASDAQ National Market
     System or another national exchange upon which the Company's Common Stock
     is traded or as otherwise determined by the Board, based on any reasonable
     valuation method.

          (7) "Option" means an option granted under the Plan.

          (8) "Optionee" means a person to whom an Option, which has not
     expired, has been granted under the Plan.

          (9) "Subsidiary" or "Subsidiaries" means a subsidiary corporation or
     corporations of the Company as defined in Section 425(f) of the Code.

          (10) "Successor" means the legal representative of the estate of a
     deceased optionee or the person or persons who acquire the right to



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     exercise an Option by bequest or inheritance or by reason of the death of
     an Optionee.

          (11) "Incentive Stock Option" means an option that qualifies as an
     incentive stock option under all of the requirements of the Code.

          (12) "Incentive Stock Option Agreement" means the agreement between
     the Company and the Optionee, in such form as may from time to time be
     adopted by the Board, under which the Optionee may purchase Common Stock
     pursuant to the terms of an Incentive Stock Option granted under the Plan.

          (13) "Non-Qualified Stock Option" means an option to purchase Common
     Stock granted pursuant to the provisions of the Plan that does not qualify
     as an Incentive Stock Option.

          (14) "Non-Qualified Stock Option Agreement" means the agreement
     between the Company and the Optionee, in such form as may from time to time
     be adopted by the Board, under which the Optionee may purchase Common Stock
     pursuant to the terms of a Non-Qualified Stock Option granted under the
     Plan.

     3. Administration and Interpretation of Plan. The Plan shall be
administered by the Board. The Board shall have full and final authority in its
discretion, subject to the provisions of the Plan: (i) to determine the
individuals to whom, and the time or times at which, Options shall be granted
and the number of shares of Common Stock covered by each Option; (ii) to
construe and interpret



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the Plan; and (iii) to make all other determinations and take all other actions
deemed necessary or advisable for the proper administration of the Plan. All
such actions and determinations by the Board shall be final and conclusively
binding for all purposes and upon all persons.

     4. Common Stock Subject to Options. The maximum number of shares of Common
Stock of the Company which may be issued upon the exercise of Options granted
under the Plan is 6,797,339, computed from the date of the adoption of the
Company's 1987 Stock Option Plan through the effective date of this amended Plan
(which number includes 850,000 shares authorized by the Board of Directors on
October 26, 1999, for issuance upon the exercise of Options under the Plan),
increased on and as of January 1 of each calendar year from and including
January 1, 2000, by a number of shares equal to one percent (1%) of the number
of shares of Common Stock outstanding on December 31 of the preceding year;
subject to appropriate adjustment by the Board to reflect any stock dividend,
stock split, reverse stock split, share combination, reorganization,
recapitalization or the like, of or by the Company. The shares of Common Stock
to be issued upon the exercise of Options may be authorized but unissued shares,
shares issued and reacquired by the Company or shares bought on the open market
for the purposes of the Plan. In the event any Option shall, for any reason,
terminate or expire or be canceled or surrendered without having been exercised
in full, the shares subject to such Option, but not purchased thereunder, shall
again be available for Options to be granted under the Plan.



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     5. Participants. Options may be granted under the Plan to any person who is
an officer, director, employee or consultant of the Company or any of its
Subsidiaries.

     6. Terms and Conditions of Options. Any Option granted under the Plan shall
be evidenced by either an Incentive Stock Option Agreement or a Non-Qualified
Stock Option Agreement executed by the Company and the Optionee. Such agreement
shall be subject to the following limitations and conditions:

          (1) Option Price. The option price per share with respect to each
     Option shall be determined by the Board but in no instance shall the option
     price for an Option which is intended to qualify as an Incentive Stock
     Option be less than 100% of the Fair Market Value of a share of the Common
     Stock on the Date of Grant.

          (2) Payment of Option Price. Full payment for shares purchased upon
     exercising an Option shall be made in cash or by check, or by delivery of
     previously owned shares of Common Stock, or partly in cash or by check and
     partly in such stock. The value of shares of Common Stock delivered in
     connection with the payment of the option price shall be the Fair Market
     Value of such shares on the Date of Exercise of the Option.

          (3) Term of Option. The expiration date of each Incentive Stock Option
     shall not be more than ten (10) years from the Date of Grant. The
     expiration date of each Non-Qualified Stock Option shall not be more than
     eleven (11) years from the Date of Grant.



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          (4) Vesting of Stockholder Rights. Neither an Optionee nor his
     Successor shall have any of the rights of a stockholder of the Company
     until the certificate or certificates evidencing the shares purchased
     pursuant to the exercise of an Option are properly delivered to such
     Optionee or his Successor.

          (5) Exercise of an Option. Each Option shall be exercisable at any
     time, and from time to time, and in no particular order if the Optionee
     holds more than one Option, throughout a period commencing on or after the
     Date of Grant, as specified by the Board, and ending upon the earliest of
     the expiration, cancellation, surrender or termination of the Option;
     provided however, that no Option shall be exercisable in whole or in part
     prior to the date of stockholder approval of the Plan. Furthermore, the
     exercise of each Option shall be subject to the condition that if at any
     time the Company shall determine in its discretion that the satisfaction of
     withholding tax or other withholding liabilities, or that the listing,
     registration, or qualification of any share otherwise deliverable upon such
     exercise upon any securities exchange or under any state or federal law, or
     that the report to, or consent or approval of, stockholders or any
     regulatory body, is necessary or desirable as a condition of, or in
     connection with, such exercise or the delivery or purchase of shares
     pursuant thereto, then in any such event, such exercise shall not be
     effective unless such withholding, listing,



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     registration, qualification, report, consent or approval shall have been
     effected or obtained free of any conditions not acceptable to the Company.

          (6) Stock Appreciation Rights. Any Option may include a Stock
     Appreciation Right, either at the Date of Grant or later by amendment
     approved by the Board, and provision therefor shall be included in the
     stock option agreement at such time consistent with the terms hereof. Such
     Stock Appreciation Right shall be subject to such terms and conditions not
     inconsistent with the Plan as the Board shall impose, including the
     following:

               (1) It shall be exercisable only when and to the extent the
          Option is exercisable and only at such time as the value of the
          Company's Common Stock is equal to or greater than the option price
          specified in such Option.

               (2) It shall entitle the Optionee to surrender unexercised the
          Option in which the Stock Appreciation Right is included (or any
          portion of such Option) to the Company and to receive from the Company
          in exchange therefor that number of shares of Common Stock having an
          aggregate value equal to the excess of the Fair Market Value of one
          share, on the day immediately preceding the date on which the Stock
          Appreciation Right is exercised, over the purchase price per share
          specified in such option, times the number of shares called for by the
          Option, or portion thereof, which is so surrendered.



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          The Company, in its discretion, shall be entitled to elect to settle
          its obligation arising out of the exercise of a Stock Appreciation
          Right by the payment of cash equal to the aggregate value of the
          shares it would otherwise be obligated to deliver. The Company may
          also elect to settle such obligation partly in cash and partly in
          Common Stock. In lieu thereof, the Company shall have the right, in
          its discretion, to the extent it shall deem advisable to consent to or
          disapprove the election of the Optionee to receive cash in full or
          partial settlement of a Stock Appreciation Right.

               (3) No fractional shares shall be delivered pursuant to exercise
          of a Stock Appreciation Right but in lieu thereof a cash adjustment
          shall be made.

               (4) Notwithstanding the other provisions hereof, to the extent
          that a Stock Appreciation Right included in an Option is exercised,
          such Option shall be deemed to have been exercised to the extent of
          the number of shares of Common Stock called for by the Option or
          portion thereof which is surrendered on exercise of the Stock
          Appreciation Right, so that such shares shall no longer be reserved
          for issuance upon the exercise of Options to be granted under the
          Plan.

               (5) The Board shall have the right, without the consent or
          approval of the Optionee, at any time after the grant of a Stock




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          Appreciation Right to limit the time within or extent to which such
          Stock Appreciation Right may be exercisable, to limit the maximum
          amount of appreciation that may be recognized in connection with the
          exercise thereof or to in any other manner it, in its discretion,
          shall deem advisable amend or terminate such Stock Appreciation Right.

               (6) A Stock Appreciation Right granted pursuant to the Plan shall
          not be exercisable unless and until the Optionee shall have completed
          one (1) continuous year of full time employment with the Company
          subsequent to the time of grant of such Stock Appreciation Right. For
          the purposes hereof, full time employment shall be such as may be
          established by the Board.

               (7) The Company shall have the right at any time to amend this
          provision of the Plan dealing with Stock Appreciation Rights, and the
          provisions of any stock option agreement pursuant to the Plan dealing
          with a Stock Appreciation Right, to the extent that it, in its
          discretion, shall deem to be necessary in order to comply with the
          provisions of Rule 16b-3.

          (7) Non-ISO Tax Offset Bonus. The Board may grant a Tax Offset Bonus
     to such Optionees and on such bases as the Board shall determine,
     including, but not limited to, a Tax Offset Bonus which becomes exercisable
     only upon an Optionee's being subject to the restrictions of Section 16 of



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     the Exchange Act. A Tax Offset Bonus may be granted only with respect to a
     Non-Qualified Stock Option under the Plan, and may be granted concurrently
     with or after the grant of the Non-Qualified Stock Option. A Tax Offset
     Bonus shall entitle an Optionee to receive from the Company or a Subsidiary
     an amount in cash no greater than the then existing maximum statutory
     Federal income tax rate (including any surtax or similar charge or
     assessment) for individuals multiplied by the amount of ordinary income, if
     any, realized by the Optionee for Federal income tax purposes as a result
     of the exercise of the Non-Qualified Stock Option. The Board may cancel or
     place a limit on the term of, or the amount payable for, any Tax Offset
     Bonus at any time. The Board shall determine all other terms and provisions
     of any Tax Offset Bonus grant. The Company shall not be required to fund
     such Tax Offset Bonus prior to the due date for such taxes, and the
     proceeds of such Tax Offset Bonus shall be advanced to the Optionee in the
     form of a check payable to the Internal Revenue Service for the account of
     the Optionee or such other method as the Board may determine. The Board
     shall have the right to require an Optionee to present reasonable proof of
     the amount of such taxes as a condition precedent to the making of such
     payment. The Company shall be under no obligation of any nature to grant
     any Tax Offset Bonus to any Optionee at any time.



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          (8) Company Loans. The Company may make stock purchase loans in
     connection with Option exercises upon the following terms and conditions:


               (1) Upon the exercise by an Optionee of his Option, or any part
          thereof, and the Optionee's request for a loan pursuant hereto, the
          Company, upon approval by the Board, may loan said Optionee, for the
          sole purpose of purchasing Common Stock from the Company pursuant to
          the exercise of such Option, an amount equal to the excess of the
          exercise price of the Option over the aggregate par value of the
          Common Stock which the Optionee has elected to purchase pursuant to
          such exercise; provided, however, that the Optionee shall execute
          concurrently a promissory note in form satisfactory to the Board for
          such amount payable to the order of the Company;

               (2) The Company shall have no obligation to make any loan to any
          Optionee at any time;

               (3) The promissory note referenced hereinbefore shall provide for
          interest to be payable upon the outstanding principal balance thereof
          at such rate and times as the Board may determine. Such note shall
          also provide that the Board may require the Optionee to secure the
          payment thereof at any time with collateral deemed adequate by the
          Board in its sole discretion. Such note shall mature, and all
          outstanding principal and interest shall become



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          immediately due and payable in installments or in lump sum at such
          time or times as the Board shall provide. The note will provide for
          prepayment of principal and accrued interest in whole or in part from
          time to time without premium or penalty and may be extended or
          modified, from time to time, at the Board's discretion. The note shall
          provide for acceleration of maturity by the Company upon the happening
          of any events determined appropriate by the Board, including without
          limitation, any of the following events:

                    (1) failure of the Optionee to pay or perform any term or
               provision thereof; or

                    (2) termination of the Optionee's employment with the
               Company or a Subsidiary for any reason, except retirement,
               disability or death; or

                    (3) if the Optionee shall execute an assignment for the
               benefit of creditors, or admit in writing his ability to pay his
               debts generally as they become due, or voluntarily seek the
               benefit of, or have a petition filed against him seeking the
               benefit of, a judgment, order or decree filed against him
               pursuant to any bankruptcy, insolvency, reorganization, or
               similar debtor relief law affecting the rights of creditors
               generally; or



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                    (4) failure of the Optionee to have discharged within a
               period of thirty (30) days after the commencement thereof any
               attachment, sequestration, or similar proceeding against any of
               the assets of the Optionee; or

                    (5) failure of the Optionee to pay any money judgment
               against him at least thirty (30) days prior to the date on which
               any of his assets may be lawfully sold to satisfy such judgment;
               or

                    (6) failure or refusal of the Optionee to comply with any of
               the terms and conditions of his stock option agreement or any
               other oral or written agreement with the Company; or

                    (7) failure or refusal of the Optionee to provide adequate
               security for payment of the promissory note immediately upon
               request for collateral by the Board; or

                    (8) the divorce of the Optionee, unless arrangements
               satisfactory to the Board are agreed to prior to the entry of the
               divorce decree.

          (9) Nontransferability of Option. Other than by will or by laws of
     descent and distribution, an Option granted under the Plan shall be
     transferable or assignable by an Optionee only if and under terms and
     conditions approved by the Board, in its sole discretion. Subject to the
     foregoing sentence, each Option shall be exercisable, during the Optionee's



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     lifetime, only by him. No Option or the shares covered thereby shall be
     pledged or hypothecated in any way and no Option or the shares covered
     thereby shall be subject to execution, attachment, or similar process
     except with the prior express written consent of the Board.

          (10) Termination of Employment. Except as may otherwise be authorized
     by the Board, upon termination of an Optionee's employment with the Company
     or with any of its Subsidiaries for any reason other than retirement,
     permanent disability or death, any and all outstanding Option(s) of such
     Optionee shall immediately thereupon be null and void. Neither the adoption
     of this Plan nor the grant of an Option to an eligible person shall alter
     in any way the Company's or the relevant Subsidiary's rights to terminate
     such person's employment or directorship at any time with or without cause
     nor does it confer upon such person any rights or privileges to continued
     employment, or any other rights and privileges, except as specifically
     provided in the Plan.

          (11) Death of Optionee. Except as may otherwise be authorized by the
     Board, if an Optionee dies while in the employ of the Company or any
     Subsidiary, his option privileges shall be limited to the shares which were
     immediately purchasable by him at the date of death and such option
     privileges shall expire unless exercised by his Successor prior to the date
     of its expiration or one (1) year from the date of the Optionee's death,
     whichever occurs first.



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          (12) Ten Percent Stockholder. Notwithstanding anything herein to the
     contrary, an Option which is intended to qualify as an Incentive Stock
     Option shall be granted hereunder to any Optionee who, immediately before
     such Option is granted, beneficially owns, directly or indirectly, more
     than 10% of the total voting power of all classes of stock of the Company
     only if both of the following conditions are met:

               (1) The option price per share shall be no less than 110% of the
          Fair Market Value of a share of Common Stock on the Date of Grant; and

               (2) The expiration date of the Option shall be not more than five
          (5) years from the Date of Grant.


          (13) Other Terms. Each Incentive Stock Option Agreement or
     Non-Qualified Stock Option Agreement, as the case may be, may contain such
     other provisions as the Board in its discretion may determine, including,
     without limitation:

               (1) in the event that an Option shall be immediately exercisable,
          any provision which shall provide that the shares acquired pursuant
          thereto shall not be deemed to have been issued pursuant to a fully
          vested stock option and thereby subject to repurchase rights (if any)
          contained in the shareholder's agreement with the Optionee, entered
          into pursuant to Paragraph 10 hereof;



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               (2) any provision which shall condition the exercise of all or
          part of an Option upon such matters as the Board may deem appropriate
          (if any) such as the passage of time, or the attainment of certain
          performance goals, appropriate to reflect the contribution of the
          Optionee to the performance of the Company;

               (3) any provision which would accelerate the exercisability of an
          Option in spite of any provision contained in an Option pursuant to
          clause (2) above or otherwise, under such circumstances as the Board
          may deem appropriate; and

               (4) the manner in which an Option is to be exercised.

     7. Allotment of Shares. The grant of an Option shall not be deemed either
to entitle the Optionee to, or disqualify the Optionee from, participation in
any other grant of options under this Plan or any other stock option plan of the
Company. The number of shares allotted to each Optionee shall be determined as
follows: The Board shall, in its discretion, determine the number of shares of
Common Stock to be offered from time to time by grant of Options to officers,
key employees and consultants of the Company or its Subsidiaries; provided that
the aggregate Fair Market Value (determined as of the time the option is
granted) of the Common Stock with respect to which Options which are intended to
qualify as Incentive Stock Options are exercisable for the first time by such
Optionee during any calendar year (under all such plans of the Optionee's
employer corporation and its parent and subsidiary corporations) shall not
exceed $100,000.



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     8. Adjustments. The number of shares of Common Stock covered by each
outstanding Option granted under the Plan and the option price shall be adjusted
to reflect, as deemed appropriate by the Board in its discretion, any stock
dividend, stock split, reverse stock split, share combination, exchange of
shares, recapitalization, merger, consolidation, separation, reorganization,
liquidation or the like of or by the Company. Decisions by the Board as to what
adjustments shall be made, and the extent thereof, shall be final, binding and
conclusive on all Optionees.

     9. Designation of Incentive Stock Options. The Board shall cause each
Option granted hereunder to be clearly designated in the agreement evidencing
such Option, at the time of grant, as to whether or not it is intended to
qualify as an Incentive Stock Option.

     10. Execution of Shareholder's Agreement. Options may only be exercised
hereunder by employees who have executed a Shareholder's Agreement in such form
as the Board may adopt from time to time.

     11. Notices. Whenever any notice is required or permitted hereunder, such
notice must be in writing and personally delivered or sent by mail. Any notice
required or permitted to be delivered hereunder shall be deemed to be delivered
on the date which it is personally delivered, or, whether actually received or
not, on the third business day after it is deposited in the United States mail,



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certified or registered, postage prepaid, addressed to the person who is to
receive it at the address which such person has theretofore specified by written
notice delivered in accordance herewith. The Company or an Optionee may change,
at any time and from time to time, by written notice to the other, the address
which it or he had theretofore specified for receiving notices. Until changed in
accordance herewith, the Company and each Optionee shall specify as its and his
address for receiving notices the address set forth in the option agreement
pertaining to the shares to which such notice relates.

     12. Amendment or Discontinuance. The Plan and any Option outstanding
hereunder may be amended or discontinued by the Board without the approval of
the stockholders of the Company, except that the Board may not, except as
expressly provided in the Plan, increase the aggregate number of shares which
may be issued under Options granted pursuant to the Plan, materially amend the
eligibility requirements of the Plan or materially increase the benefits which
may accrue to participants under the Plan, without such approval (if any) as may
be required pursuant to applicable law or the requirements of any national stock
exchange upon which the Company's Common Stock is traded.

     13. Effect of the Plan. Neither the adoption of this Plan nor any action of
the Board shall be deemed to give any officer or employee any right to be
granted an option to purchase Common Stock of the Company or any of its
Subsidiaries, or any other rights except as may be evidenced by a stock option
agreement, or any amendment thereto, duly authorized by the Board and executed
on behalf of the Company and then only to the extent and on the terms and
conditions expressly set forth therein.



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     14. Grant of Incentive Stock Options. No Incentive Stock Options shall be
granted pursuant to this Plan after the expiration of ten years from the date of
the earlier of: (i) the date the Plan is adopted, or (ii) the date the Plan is
approved by the stockholders of the Company.










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