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                                                                    EXHIBIT 10.4


                           QUALITY SEMICONDUCTOR, INC.

                        1993 DIRECTORS' STOCK OPTION PLAN


                   (AMENDED AND RESTATED AS OF APRIL 24, 1998)


        1.      Purposes of the Plan. The purposes of this Directors' Stock
Option Plan are to attract and retain the best available personnel for service
as Directors of the Company, to provide additional incentive to the Outside
Directors of the Company to serve as Directors, and to encourage their continued
service on the Board.

                  All options granted hereunder shall be "nonstatutory stock
options".

        2.      Definitions. As used herein, the following definitions shall
apply:

                (a)     "Board" shall mean the Board of Directors of the
Company.

                (b)     "Code" shall mean the Internal Revenue Code of 1986, as
amended.

                (c)     "Common Stock" shall mean the Common Stock of the
Company.

                (d)     "Company" shall mean Quality Semiconductor, Inc., a
California corporation.

                (e)     "Continuous Status as a Director" shall mean the absence
of any interruption or termination of service as a Director.

                (f)     "Director" shall mean a member of the Board.

                (g)     "Employee" shall mean any person, including officers and
directors, employed by the Company or any Parent or Subsidiary of the Company.
The payment of a director's fee by the Company shall not be sufficient in and of
itself to constitute "employment" by the Company.

                (h)     "Exchange Act" shall mean the Securities Exchange Act of
1934, as amended.

                (i)     "Option" shall mean a stock option granted pursuant to
the Plan.

                (j)     "Optioned Stock" shall mean the Common Stock subject to
an Option.

                (k)     "Optionee" shall mean an Outside Director who receives
an Option.

                (l)     "Outside Director" shall mean a Director who is not an
Employee.

                (m)     "Parent" shall mean a "parent corporation", whether now
or hereafter existing, as defined in Section 424(e) of the Code.

                (n)     "Plan" shall mean this 1993 Directors' Stock Option
Plan.


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                (o)     "Share" shall mean a share of the Common Stock, as
adjusted in accordance with Section 11 of the Plan.

                (p)     "Subsidiary" shall mean a "subsidiary corporation",
whether now or hereafter existing, as defined in Section 424(f) of the Code.

        3.      Stock Subject to the Plan. Subject to the provisions of Section
11 of the Plan, the maximum aggregate number of Shares which may be optioned and
sold under the Plan is 100,000 Shares (the "Pool") of Common Stock. The Shares
may be authorized, but unissued, or reacquired Common Stock.

        If an Option should expire or become unexercisable for any reason
without having been exercised in full, the unpurchased Shares which were subject
thereto shall, unless the Plan shall have been terminated, become available for
future grant under the Plan. If Shares which were acquired upon exercise of an
Option are subsequently repurchased by the Company, such Shares shall not in any
event be returned to the Plan and shall not become available for future grant
under the Plan.

        4.      Administration of and Grants of Options under the Plan.

                (a)     Administrator. Except as otherwise required herein, the
Plan shall be administered by the Board.

                (b)     Procedure for Grants. All grants of Options hereunder
shall be automatic and nondiscretionary and shall be made strictly in accordance
with the following provisions:

                        (i)     No person shall have any discretion to select
which Outside Directors shall be granted Options or to determine the number of
Shares to be covered by Options granted to Outside Directors.

                        (ii)    Each Outside Director shall be automatically
granted an Option to purchase 10,000 Shares (the "First Option") on the date on
which the later of the following events occurs: (A) the effective date of this
Plan, as determined in accordance with Section 6 hereof, or (B) the date on
which such person first becomes an Outside Director, whether through election by
the shareholders of the Company or appointment by the Board of Directors to fill
a vacancy.

                        (iii)   After the First Option has been granted to an
Outside Director, such Outside Director shall thereafter be automatically
granted an Option to purchase 5,000 Shares (a "Subsequent Option") on each
anniversary of the Effective Date, if on such date, he or she shall have served
on the Board for at least six (6) months.

                        (iv)    Notwithstanding the provisions of subsections
(ii) and (iii) hereof, in the event that a grant would cause the number of
Shares subject to outstanding Options plus the number of Shares previously
purchased upon exercise of Options to exceed the Pool, then each such automatic
grant shall be for that number of Shares determined by dividing the total number
of Shares remaining available for grant by the number of Outside Directors on
the automatic grant date. Any further grants shall then be deferred until such
time, if any, as additional Shares become available for grant under the Plan
through action of the shareholders to increase the number of Shares which may be
issued under the Plan or through cancellation or expiration of Options
previously granted hereunder.


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                        (v)     Notwithstanding the provisions of subsections
(ii) and (iii) hereof, any grant of an Option made before the Company has
obtained shareholder approval of the Plan in accordance with Section 17 hereof
shall be conditioned upon obtaining such shareholder approval of the Plan in
accordance with Section 17 hereof.

                        (vi)    The terms of each First Option granted hereunder
shall be as follows:

                                (1)     the First Option shall be exercisable
only while the Outside Director remains a Director of the Company, except as set
forth in Section 9 hereof.

                                (2)     the exercise price per Share shall be
100% of the fair market value per Share at the beginning of the date of grant of
the First Option, determined in accordance with Section 8 hereof.

                                (3)     the First Option shall become
exercisable in installments cumulatively as to 25% of the Shares subject to the
First Option on each of the first, second, third and fourth anniversaries of the
date of grant of the First Option.

                        (vii)   The terms of each Subsequent Option granted
hereunder shall be as follows:

                                (1)     the Subsequent Option shall be
exercisable only while the Outside Director remains a Director of the Company,
except as set forth in Section 9 hereof.

                                (2)     the exercise price per Share shall be
100% of the fair market value per Share at the beginning of the date of grant of
the Subsequent Option, determined in accordance with Section 8 hereof.

                                (3)     the Subsequent Option shall become
exercisable as to one hundred percent (100%) of the Shares subject to the
Subsequent Option on the fourth anniversary of the date of grant of the
Subsequent Option.

                (c)     Powers of the Board. Subject to the provisions and
restrictions of the Plan, the Board shall have the authority, in its discretion:
(i) to determine, upon review of relevant information and in accordance with
Section 8(b) of the Plan, the fair market value of the Common Stock; (ii) to
determine the exercise price per share of Options to be granted, which exercise
price shall be determined in accordance with Section 8(a) of the Plan; (iii) to
interpret the Plan; (iv) to prescribe, amend and rescind rules and regulations
relating to the Plan; (v) to authorize any person to execute on behalf of the
Company any instrument required to effectuate the grant of an Option previously
granted hereunder; and (vi) to make all other determinations deemed necessary or
advisable for the administration of the Plan.

                (d)     Effect of Board's Decision. All decisions,
determinations and interpretations of the Board shall be final and binding on
all Optionees and any other holders of any Options granted under the Plan.

                (e)     Suspension or Termination of Option. If the President or
his or her designee reasonably believes that an Optionee has committed an act of
misconduct, the President may suspend the Optionee's right to exercise any
option pending a determination by the Board of Directors (excluding the Outside
Director accused of such misconduct). If the Board of Directors (excluding the
Outside Director accused of such misconduct) determines an Optionee has
committed an act of embezzlement, fraud, 


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dishonesty, nonpayment of an obligation owed to the Company, breach of fiduciary
duty or deliberate disregard of the Company rules resulting in loss, damage or
injury to the Company, or if an Optionee makes an unauthorized disclosure of any
Company trade secret or confidential information, engages in any conduct
constituting unfair competition, induces any Company customer to breach a
contract with the Company or induces any principal for whom the Company acts as
agent to terminate such agency relationship, neither the Optionee nor his or her
estate shall be entitled to exercise any option whatsoever. In making such
determination, the Board of Directors (excluding the Outside Director accused of
such misconduct) shall act fairly and shall give the Optionee an opportunity to
appear and present evidence on Optionee's behalf at a hearing before the Board
or a committee of the Board.

        5.      Eligibility. Options may be granted only to Outside Directors.
All Options shall be automatically granted in accordance with the terms set
forth in Section 4(b) hereof. An Outside Director who has been granted an Option
may, if he or she is otherwise eligible, be granted an additional Option or
Options in accordance with such provisions.

        The Plan shall not confer upon any Optionee any right with respect to
continuation of service as a Director or nomination to serve as a Director, nor
shall it interfere in any way with any rights which the Director or the Company
may have to terminate his or her directorship at any time.

        6.      Term of Plan; Effective Date. The Plan shall become effective on
the effectiveness of the registration statement under the Securities Act of 1933
relating to the Company's initial public offering of securities. It shall
continue in effect for a term of ten (10) years unless sooner terminated under
Section 13 of the Plan.

        7.      Term of Option. The term of each Option shall be ten (10) years
from the date of grant thereof.

        8.      Exercise Price and Consideration.

                (a)     Exercise Price. The per Share exercise price for the
Shares to be issued pursuant to exercise of an Option shall be 100% of the fair
market value per Share on the date of grant of the Option.

                (b)     Fair Market Value. The fair market value shall be
determined by the Board in its discretion; provided, however, that where there
is a public market for the Common Stock, the fair market value per Share shall
be the mean of the bid and asked prices of the Common Stock in the
over-the-counter market on the date of grant, as reported in The Wall Street
Journal (or, if not so reported, as otherwise reported by the National
Association of Securities Dealers Automated Quotation ("NASDAQ") System) or, in
the event the Common Stock is traded on the NASDAQ National Market System or
listed on a stock exchange, the fair market value per Share shall be the closing
price on such system or exchange on the date of grant of the Option, as reported
in The Wall Street Journal. With respect to any Options granted hereunder
concurrently with the initial effectiveness of the Plan, the fair market value
shall be equal to the initial public offering price of the Company's Common
Stock as set forth on the cover page of the prospectus relating to such initial
public offering.

                (c)     Form of Consideration. The consideration to be paid for
the Shares to be issued upon exercise of an Option shall consist entirely of
cash, check, other Shares of Common Stock having a fair market value on the date
of surrender equal to the aggregate exercise price of the Shares as to which
said Option shall be exercised (which, if acquired from the Company, shall have
been held for at least six 


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months), or any combination of such methods of payment and/or any other
consideration or method of payment as shall be permitted under applicable
corporate law.

        9.      Exercise of Option.

                (a)     Procedure for Exercise; Rights as a Shareholder. Any
Option granted hereunder shall be exercisable at such times as are set forth in
Section 4(b) hereof; provided, however, that no Options shall be exercisable
prior to shareholder approval of the Plan in accordance with Section 17 hereof
has been obtained.

                An Option may not be exercised for a fraction of a Share.

                An Option shall be deemed to be exercised when written notice of
such exercise has been given to the Company in accordance with the terms of the
Option by the person entitled to exercise the Option and full payment for the
Shares with respect to which the Option is exercised has been received by the
Company. Full payment may consist of any consideration and method of payment
allowable under Section 8(c) of the Plan. Until the issuance (as evidenced by
the appropriate entry on the books of the Company or of a duly authorized
transfer agent of the Company) of the stock certificate evidencing such Shares,
no right to vote or receive dividends or any other rights as a shareholder shall
exist with respect to the Optioned Stock, notwithstanding the exercise of the
Option. A share certificate for the number of Shares so acquired shall be issued
to the Optionee as soon as practicable after exercise of the Option. No
adjustment will be made for a dividend or other right for which the record date
is prior to the date the stock certificate is issued, except as provided in
Section 11 of the Plan.

                Exercise of an Option in any manner shall result in a decrease
in the number of Shares which thereafter may be available, both for purposes of
the Plan and for sale under the Option, by the number of Shares as to which the
Option is exercised.

                (b)     Termination of Status as a Director. If an Outside
Director ceases to serve as a Director, he or she may, but only within ninety
(90) days (or such other period of time not exceeding six (6) months as is
determined by the Board) after the date he or she ceases to be a Director of the
Company, exercise his or her Option to the extent that he or she was entitled to
exercise it at the date of such termination. Notwithstanding the foregoing, in
no event may the Option be exercised after its term set forth in Section 7 has
expired. To the extent that such Outside Director was not entitled to exercise
an Option at the date of such termination, or does not exercise such Option
(which he or she was entitled to exercise) within the time specified herein, the
Option shall terminate.

                (c)     Disability of Optionee. Notwithstanding the provisions
of Section 9(b) above, in the event a Director is unable to continue his or her
service as a Director with the Company as a result of his or her total and
permanent disability (as defined in Section 22(e)(3) of the Internal Revenue
Code), he or she may, but only within six (6) months (or such other period of
time not exceeding twelve (12) months as is determined by the Board) from the
date of such termination, exercise his or her Option to the extent he or she was
entitled to exercise it at the date of such termination. Notwithstanding the
foregoing, in no event may the Option be exercised after its term set forth in
Section 7 has expired. To the extent that he or she was not entitled to exercise
the Option at the date of termination, or if he or she does not exercise such
Option (which he or she was entitled to exercise) within the time specified
herein, the Option shall terminate.

                (d)     Death of Optionee. In the event of the death of an
Optionee:


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                        (i)     During the term of the Option who is, at the
time of his or her death, a Director of the Company and who shall have been in
Continuous Status as a Director since the date of grant of the Option, the
Option may be exercised, at any time within six (6) months (or such lesser
period of time as is determined by the Board) following the date of death, by
the Optionee's estate or by a person who acquired the right to exercise the
Option by bequest or inheritance, but only to the extent of the right to
exercise that would have accrued had the Optionee continued living and remained
in Continuous Status as Director for six (6) months (or such lesser period of
time as is determined by the Board) after the date of death. Notwithstanding the
foregoing, in no event may the Option be exercised after its term set forth in
Section 7 has expired.

                        (ii)    Within three (3) months (or such lesser period
of time as is determined by the Board) after the termination of Continuous
Status as a Director, the Option may be exercised, at any time within six (6)
months following the date of death, by the Optionee's estate or by a person who
acquired the right to exercise the Option by bequest or inheritance, but only to
the extent of the right to exercise that had accrued at the date of termination.
Notwithstanding the foregoing, in no event may the option be exercised after its
term set forth in Section 7 has expired.

        10.     Nontransferability of Options. The Option may not be sold,
pledged, assigned, hypothecated, transferred, or disposed of in any manner other
than by will or by the laws of descent or distribution. The designation of a
beneficiary by an Optionee does not constitute a transfer. An Option may be
exercised during the lifetime of an Optionee only by the Optionee or a
transferee permitted by this Section.

        11.     Adjustments Upon Changes in Capitalization or Merger. Subject to
any required action by the shareholders of the Company, the number of shares of
Common Stock covered by each outstanding Option, and the number of shares of
Common Stock which have been authorized for issuance under the Plan but as to
which no Options have yet been granted or which have been returned to the Plan
upon cancellation or expiration of an Option, as well as the price per share of
Common Stock covered by each such outstanding Option, shall be proportionately
adjusted for any increase or decrease in the number of issued shares of Common
Stock resulting from a stock split, reverse stock split, stock dividend,
combination or reclassification of the Common Stock, or any other increase or
decrease in the number of issued shares of Common Stock effected without receipt
of consideration by the Company; provided, however, that conversion of any
convertible securities of the Company shall not be deemed to have been "effected
without receipt of consideration." Such adjustment shall be made by the Board,
whose determination in that respect shall be final, binding and conclusive.
Except as expressly provided herein, no issuance by the Company of shares of
stock of any class, or securities convertible into shares of stock of any class,
shall affect, and no adjustment by reason thereof shall be made with respect to,
the number or price of shares of Common Stock subject to an Option.

        In the event of the proposed dissolution or liquidation of the Company,
the Option will terminate immediately prior to the consummation of such proposed
action, unless otherwise provided by the Board. The Board may, in the exercise
of its sole discretion in such instances, declare that any Option shall
terminate as of a date fixed by the Board and give each Optionee the right to
exercise his or her Option as to all or any part of the Optioned Stock,
including Shares as to which the Option would not otherwise be exercisable. In
the event of a proposed sale of all or substantially all of the assets of the
Company, or the merger of the Company with or into another corporation, the
Option shall be assumed or an equivalent option shall be substituted by such
successor corporation or a parent or subsidiary of such successor corporation,
unless the Board (or a committee of the Board composed of "disinterested
persons," as such term is defined in Rule 16b-3 under the Exchange Act, if
required for such purpose) 


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determines, in the exercise of its sole discretion and in lieu of such
assumption or substitution, that the Optionee shall have the right to exercise
the Option as to some or all of the Optioned Stock, including Shares as to which
the Option would not otherwise be exercisable. If the Board (or such committee)
makes an Option exercisable in lieu of assumption or substitution in the event
of a merger or sale of assets, the Board shall notify the Optionee that the
Option shall be exercisable for a period of fifteen (15) days from the date of
such notice, and the Option will terminate upon the expiration of such period.

        12.     Time of Granting Options. The date of grant of an Option shall,
for all purposes, be the date determined in accordance with Section 4(b) hereof.
Notice of the determination shall be given to each Outside Director to whom an
Option is so granted within a reasonable time after the date of such grant.

        13.     Amendment and Termination of the Plan.

                (a)     Amendment and Termination. The Board may amend or
terminate the Plan from time to time in such respects as the Board may deem
advisable; provided that, to the extent necessary and desirable to comply with
Rule 16b-3 under the Exchange Act (or any other applicable law or regulation),
the Company shall obtain approval of the shareholders of the Company to Plan
amendments to the extent and in the manner required by such law or regulation.
Notwithstanding the foregoing, the provisions set forth in Section 4 of this
Plan (and any other Sections of this Plan that affect the formula award terms
required to be specified in this Plan by Rule 16b-3) shall not be amended more
than once every six months, other than to comport with changes in the Code, the
Employee Retirement Income Security Act of 1979, as amended, or the rules
thereunder.

                (b)     Effect of Amendment or Termination. Any such amendment
or termination of the Plan that would impair the rights of any Optionee shall
not affect Options already granted to such Optionee and such Options shall
remain in full force and effect as if this Plan had not been amended or
terminated, unless mutually agreed otherwise between the Optionee and the Board,
which agreement must be in writing and signed by the Optionee and the Company.

        14.     Conditions Upon Issuance of Shares. Shares shall not be issued
pursuant to the exercise of an Option unless the exercise of such Option and the
issuance and delivery of such Shares pursuant thereto shall comply with all
relevant provisions of law, including, without limitation, the Securities Act of
1933, as amended, the Exchange Act, the rules and regulations promulgated
thereunder, state securities laws, and the requirements of any stock exchange
upon which the Shares may then be listed, and shall be further subject to the
approval of counsel for the Company with respect to such compliance.

                As a condition to the exercise of an Option, the Company may
require the person exercising such Option to represent and warrant at the time
of any such exercise that the Shares are being purchased only for investment and
without any present intention to sell or distribute such Shares, if, in the
opinion of counsel for the Company, such a representation is required by any of
the aforementioned relevant provisions of law.

                Inability of the Company to obtain authority from any regulatory
body having jurisdiction, which authority is deemed by the Company's counsel to
be necessary to the lawful issuance and sale of any Shares hereunder, shall
relieve the Company of any liability in respect of the failure to issue or sell
such Shares as to which such requisite authority shall not have been obtained.


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        15.     Reservation of Shares. The Company, during the term of this
Plan, will at all times reserve and keep available such number of Shares as
shall be sufficient to satisfy the requirements of the Plan.

        16.     Option Agreement. Options shall be evidenced by written option
agreements in such form as the Board shall approve.

        17.     Shareholder Approval. Continuance of the Plan shall be subject
to approval by the shareholders of the Company at or prior to the first annual
meeting of shareholders held subsequent to the granting of an Option hereunder.
If such shareholder approval is obtained at a duly held shareholders' meeting,
it may be obtained by the affirmative vote of the holders of a majority of the
outstanding shares of the Company present or represented and entitled to vote
thereon. If such shareholder approval is obtained by written consent, it may be
obtained by the written consent of the holders of a majority of the outstanding
shares of the Company.

        18.     Information to Optionees. The Company shall provide to each
Optionee, during the period for which such Optionee has one or more Options
outstanding, copies of all annual reports to shareholders, proxy statements and
other information provided to all shareholders of the Company.