EXHIBIT 4.5
 
                                  RAMBUS INC.

                                1990 STOCK PLAN
                        (as amended September 14, 1994)
                           (as amended July 5, 1995)
                        (as amended September 14, 1995)
                        (as amended September 26, 1996)
                                        
     1.   Purposes of the Plan.  The purposes of this Stock Plan are to attract
          --------------------                                                 
and retain the best available personnel for positions of substantial
responsibility, to provide additional incentive to Employees and Consultants of
the Company and its Subsidiaries and to promote the success of the Company's
business. Options granted under the Plan may be incentive stock options (as
defined under Section 422A of the Code) or non-statutory stock options, as
determined by the Administrator at the time of grant of an option and subject to
the applicable provisions of Section 422A of the Code, as amended, and the
regulations promulgated thereunder. Stock purchase rights may also be granted
under the Plan.

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

          (a) "Administrator" means the Board or any of its Committees appointed
               -------------                                                    
pursuant to Section 4 of the Plan.

          (b) "Board" means the Board of Directors of the Company.
               -----                                              

          (c) "Code" means the Internal Revenue Code of 1986, as amended.
               ----                                                      

          (d) "Committee"  means the Committee appointed by the Board of
               ---------                                                
Directors in accordance with paragraph (a) of Section 4 of the Plan.

          (e) "Common Stock" means the Common Stock of the Company.
               ------------                                        

          (f) "Company" means Rambus Inc., a California corporation.
               -------                                              

          (g) "Consultant" means any person, including an advisor, who is
               ----------                                                
engaged by the Company or any Parent or Subsidiary to render services and is
compensated for such services, and any director of the Company whether
compensated for such services or not provided that if and in the event the
Company registers any class of any equity security pursuant to the Exchange Act,
the term Consultant shall thereafter not include directors who are not
compensated for their services or are paid only a director's fee by the Company.

          (h) "Continuous Status as an Employee" means the absence of any
               --------------------------------                          
interruption or termination of the employment relationship by the Company or any
Subsidiary. Continuous Status as an Employee shall not be considered interrupted
in the case of: (i) sick leave; (ii) military leave; (iii) any other leave of
absence approved by the Board, provided that such leave is for a period of not
more than ninety (90) days, unless reemployment upon the expiration of such
leave is guaranteed by contract or statute, or unless provided otherwise
pursuant to Company policy adopted from time to

 
time; or (iv) in the case of transfers between locations of the Company or
between the Company, its Subsidiaries or its successor.

          (i) "Employee" means 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 to constitute
"employment" by the Company.

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

          (k) "Fair Market Value" means, as of any date, the value of Common
               -----------------                                            
Stock determined as follows:

               (i)   If the Common Stock is listed on any established stock
exchange or a national market system including without limitation the National
Market System of the National Association of Securities Dealers, Inc. Automated
Quotation ("NASDAQ") System, its Fair Market Value shall be the closing sales
price for such stock (or the closing bid, if no sales were reported, as quoted
on such system or exchange, or the exchange with the greatest volume of trading
in Common Stock, for the last market trading day prior to the time of
determination) as reported in the Wall Street Journal or such other source as
the Administrator deems reliable;

               (ii)  If the Common Stock is quoted on the NASDAQ System (but not
on the National Market System thereof) or regularly quoted by a recognized
securities dealer but selling prices are not reported, its Fair Market Value
shall be the mean between the high and low asked prices for the Common Stock or;

               (iii) In the absence of an established market for the Common
Stock, the Fair Market Value thereof shall be determined in good faith by the
Administrator.

          (l) "Incentive Stock Option" means an Option intended to qualify as an
               ----------------------                                           
incentive stock option within the meaning of Section 422A of the Code.

          (m) "Nonstatutory Stock Option" means an Option not intended to
               -------------------------                                 
qualify as an Incentive Stock Option.

          (n) "Evergreen Stock Option" means an Option which shall vest 100% as
               ----------------------                                          
to the shares subject to such Option one year from the date that all options
granted previous to, and currently held by, the Optionee have vested in full.

          (o)  "Evergreen II Stock Option" means an Option which shall vest
                -------------------------                                  
cumulatively as to 1/12 of the shares subject to such Option for each month
which has expired (i) in the case of Evergreen II Stock Options granted prior to
September 14, 1995, since the date all options granted previous to, and
currently held by, the Optionee have vested in full and (ii) in the case of
Evergreen II Stock Options granted on or after September 14, 1995, since the
date that all new hire Options, rehire 

                                      -2-

 
Options, Evergreen Stock Options and Evergreen II Stock Options granted
previously to, and currently held by, the Optionee have vested in full.

          (p) "Option" means a stock option granted pursuant to the Plan.
               ------                                                    

          (q) "Optioned Stock" means the Common Stock subject to an Option.
               --------------                                              

          (r) "Optionee" means an Employee or Consultant who receives an Option.
               --------                                                         

          (s) "Parent" means a "parent corporation", whether now or hereafter
               ------                                                        
existing, as defined in Section 425(e) of the Code.

          (t) "Plan" means this 1990 Stock Plan.
               ----                             

          (u) "Restricted Stock" means shares of Common Stock acquired pursuant
               ----------------                                                
to a grant of Stock Purchase Rights under Section 11 below.

          (v) "Share" means a share of the Common Stock, as adjusted in
               -----                                                   
accordance with Section 13 of the Plan.

          (w) "Subsidiary" means a "subsidiary corporation", whether now or
               ----------                                                  
hereafter existing, as defined in Section 425(f) of the Code.

     3.   Stock Subject to the Plan.  Subject to the provisions of Section 13 of
          -------------------------                                             
the Plan, the maximum aggregate number of shares which may be optioned and sold
under the Plan is 6,875,000 shares 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.

     4.   Administration of the Plan.
          -------------------------- 

          (a)  Procedure.
               --------- 

               (i)   Administration With Respect to Directors and Officers. With
                     -----------------------------------------------------  
respect to grants of Options or Stock Purchase Rights to Employees who are also
officers or directors of the Company, the Plan shall be administered by (A) the
Board if the Board may administer the Plan in compliance with Rule 16b-3
promulgated under the Exchange Act or any successor thereto ("Rule 16b-3") with
respect to a plan intended to qualify thereunder as a discretionary plan, or (B)
a Committee designated by the Board to administer the Plan, which Committee
shall be constituted in such a manner as to permit the Plan to comply with Rule
16b-3 with respect to a plan intended to 

                                      -3-

 
qualify thereunder as a discretionary plan. Once appointed, such Committee shall
continue to serve in its designated capacity until otherwise directed by the
Board. From time to time the Board may increase the size of the Committee and
appoint additional members thereof, remove members (with or without cause) and
appoint new members in substitution therefor, fill vacancies, however caused,
and remove all members of the Committee and thereafter directly administer the
Plan, all to the extent permitted by Rule 16b-3 with respect to a plan intended
to qualify thereunder as a discretionary plan.

               (ii) Multiple Administrative Bodies.  If permitted by Rule 
                    ------------------------------           
16b-3, the Plan may be administered by different bodies with respect to
directors, non-director officers and Employees who are neither directors nor
officers.

               (iii) Administration With Respect to Consultants and Other
                     ----------------------------------------------------
Employees. With respect to grants of Options or Stock Purchase Rights to
- ---------
Employees or Consultants who are neither directors nor officers of the Company,
the Plan shall be administered by (A) the Board or (B) a Committee designated by
the Board, which Committee shall be constituted in such a manner as to satisfy
the legal requirements relating to the administration of incentive stock option
plans, if any, of California corporate and securities laws and of the Code (the
"Applicable Laws"). Once appointed, such Committee shall continue to serve in
its designated capacity until otherwise directed by the Board. From time to time
the Board may increase the size of the Committee and appoint additional members
thereof, remove members (with or without cause) and appoint new members in
substitution therefor, fill vacancies, however caused, and remove all members of
the Committee and thereafter directly administer the Plan, all to the extent
permitted by the Applicable Laws.

          (b) Powers of the Administrator.  Subject to the provisions of the
              ---------------------------                                   
Plan and in the case of a Committee, the specific duties delegated by the Board
to such Committee, the Administrator shall have the authority, in its
discretion:

               (i)   to determine the Fair Market Value of the Common Stock, in
accordance with Section 2(k) of the Plan;

               (ii)  to select the officers, Consultants and Employees to whom
Options and Stock Purchase Rights may from time to time be granted hereunder;

               (iii) to determine whether and to what extent Options and Stock
Purchase Rights or any combination thereof, are granted hereunder;

               (iv)  to determine the number of shares of Common Stock to be
covered by each such award granted hereunder;

               (v)   to approve forms of agreement for use under the Plan;

               (vi)  to determine the terms and conditions, not inconsistent
with the terms of the Plan, of any award granted hereunder (including, but not
limited to, the share price and any 

                                      -4-

 
restriction or limitation, or any vesting acceleration or waiver of forfeiture
restrictions regarding any Option or other award and/or the shares of Common
Stock relating thereto, based in each case on such factors as the Administrator
shall determine, in its sole discretion);

               (vi)  to determine whether and under what circumstances an Option
may be settled in cash under subsection 9(f) instead of Common Stock;

               (vii) to determine whether, to what extent and under what
circumstances Common Stock and other amounts payable with respect to an award
under this Plan shall be deferred either automatically or at the election of the
participant (including providing for and determining the amount, if any, of any
deemed earnings on any deferred amount during any deferral period);

               (ix)  to reduce the exercise price of any Option to the then
current Fair Market Value if the Fair Market Value of the Common Stock covered
by such Option shall have declined since the date the Option was granted; and

               (x)   to determine the terms and restrictions applicable to Stock
Purchase Rights and the Restricted Stock purchased by exercising such Stock
Purchase Rights.

          (c) Effect of Committee's Decision.  All decisions, determinations and
              ------------------------------                                    
interpretations of the Administrator shall be final and binding on all Optionees
and any other holders of any Options.

     5.   Eligibility.
          ----------- 

          (a) Nonstatutory Stock Options may be granted to Employees and
Consultants. Incentive Stock Options may be granted only to Employees. Evergreen
and Evergreen II Stock Options may only be granted to Employees and Consultants
who earn more than $60,000 per year. An Employee or Consultant who has been
granted an Option may, if he is otherwise eligible, be granted an additional
Option or Options.

          (b) Each Option shall be designated in the written option agreement as
either an Incentive Stock Option or a Nonstatutory Stock Option.  However,
notwithstanding such designations, to the extent that the aggregate Fair Market
Value of the Shares with respect to which Options designated as Incentive Stock
Options are exercisable for the first time by any Optionee during any calendar
year (under all plans of the Company or any Parent or Subsidiary) exceeds
$100,000, such excess Options shall be treated as Nonstatutory Stock Options.

          (c) For purposes of Section 5(b), Incentive Stock Options shall be
taken into account in the order in which they were granted, and the Fair Market
Value of the Shares shall be determined as of the time the Option with respect
to such Shares is granted.

                                      -5-

 
          (d) The Plan shall not confer upon any Optionee any right with respect
to continuation of employment or consulting relationship with the Company, nor
shall it interfere in any way with his right or the Company's right to terminate
his employment or consulting relationship at any time, with or without cause.

     6.   Term of Plan.  The Plan shall become effective upon the earlier to
          ------------                                                      
occur of its adoption by the Board of Directors or its approval by the
shareholders of the Company as described in Section 19 of the Plan. It shall
continue in effect for a term of ten (10) years unless sooner terminated under
Section 15 of the Plan.

     7.   Term of Option.  The term of each Option shall be the term stated in
          --------------                                                      
the Option Agreement; provided, however, that in the case of an Incentive Stock
Option, the term shall be no more than ten (10) years from the date of grant
thereof or such shorter term as may be provided in the Option Agreement.
However, in the case of an Option granted to an Optionee who, at the time the
Option is granted, owns stock representing more than ten percent (10%) of the
voting power of all classes of stock of the Company or any Parent or Subsidiary,
the term of the Option shall be five (5) years from the date of grant thereof or
such shorter term as may be provided in the Option Agreement.

     8.   Option Exercise Price and Consideration.
          --------------------------------------- 

          (a) The per share exercise price for the Shares to be issued pursuant
to exercise of an Option shall be such price as is determined by the Board, but
shall be subject to the following:

               (i)   In the case of an Incentive Stock Option

          (A) granted to an Employee who, at the time of the grant of such
Incentive Stock Option, owns stock representing more than ten percent (10%) of
the voting power of all classes of stock of the Company or any Parent or
Subsidiary, the per Share exercise price shall be no less than 110% of the Fair
Market Value per Share on the date of grant.

          (B) granted to any Employee, the per Share exercise price shall be no
less than 100% of the Fair Market Value per Share on the date of grant.

               (ii)  In the case of a Nonstatutory Stock Option

          (A) granted to a person who, at the time of the grant of such Option,
owns stock representing more than ten percent (10%) of the voting power of all
classes of stock of the Company or any Parent or Subsidiary, the per Share
exercise price shall be no less than 110% of the Fair Market Value per Share on
the date of the grant.

          (B) granted to any person, the per Share exercise price shall be no
less than 85% of the Fair Market Value per Share on the date of grant.

                                      -6-

 
          (b)  The consideration to be paid for the Shares to be issued upon
exercise of an Option, including the method of payment, shall be determined by
the Administrator (and, in the case of an Incentive Stock Option, shall be
determined at the time of grant) and may consist entirely of (1) cash, (2)
check, (3) promissory note, (4) other Shares which (x) in the case of Shares
acquired upon exercise of an Option either have been owned by the Optionee for
more than six months on the date of surrender or were not acquired, directly or
indirectly, from the Company, and (y) have 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, (5) authorization from the Company to retain from the
total number of Shares as to which the Option is exercised that number of Shares
having a Fair Market Value on the date of exercise equal to the exercise price
for the total number of Shares as to which the Option is exercised, (6) delivery
of a properly executed exercise notice together with irrevocable instructions to
a broker to promptly deliver to the Company the amount of sale or loan proceeds
required to pay the exercise price, (7) by delivering an irrevocable
subscription agreement for the Shares which irrevocably obligates the option
holder to take and pay for the Shares not more than twelve months after the date
of delivery of the subscription agreement, (8) any combination of the foregoing
methods of payment, (9) or such other consideration and method of payment for
the issuance of Shares to the extent permitted under Applicable Laws.  In making
its determination as to the type of consideration to accept, the Board shall
consider if acceptance of such consideration may be reasonably expected to
benefit the Company (Section 315(b) of the California Corporations Code).

     9.   Exercise of Option.
          ------------------ 

          (a) Procedure for Exercise; Rights as a Shareholder. Any Option
              -----------------------------------------------            
granted hereunder shall be exercisable at such times and under such conditions
as determined by the Board, including performance criteria with respect to the
Company and/or the Optionee, and as shall be permissible under the terms of the
Plan.

          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, as authorized by the Board, consist of any
consideration and method of payment allowable under Section 8(b) 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. The Company shall issue (or cause to
be issued) such stock certificate promptly upon 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.

                                      -7-

 
          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 Employment. In the event of termination of an
              -------------------------                                   
Optionee's consulting relationship or Continuous Status as an Employee with the
Company (as the case may be), such Optionee may, but only within ninety (90)
days (or such other period of time as is determined by the Board, with such
determination in the case of an Incentive Stock Option being made at the time of
grant of the Option and not exceeding ninety (90) days) after the date of such
termination (but in no event later than the expiration date of the term of such
Option as set forth in the Option Agreement), exercise his Option to the extent
that Optionee was entitled to exercise it at the date of such termination.  To
the extent that Optionee was not entitled to exercise the Option at the date of
such termination, or if Optionee does not exercise such Option to the extent so
entitled within the time specified herein, the Option shall terminate.

          (c) Disability of Optionee.  Notwithstanding the provisions of Section
              ----------------------                                            
9(b) above, in the event of termination of an Optionee's Consulting relationship
or Continuous Status as an Employee as a result of his total and permanent
disability (as defined in Section 22(e)(3) of the Code), Optionee may, but only
within twelve (12) months from the date of such termination (but in no event
later than the expiration date of the term of such Option as set forth in the
Option Agreement), exercise the Option to the extent otherwise entitled to
exercise it at the date of such termination.  To the extent that Optionee was
not entitled to exercise the Option at the date of termination, or if Optionee
does not exercise such Option to the extent so entitled within the time
specified herein, the Option shall terminate.

          (d) Death of Optionee.  In the event of the death of an Optionee, the
              -----------------                                                
Option may be exercised, at any time within twelve (12) months following the
date of death (but in no event later than the expiration date of the term of
such Option as set forth in the Option Agreement), 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 the Optionee was entitled to exercise the
Option at the date of death.  To the extent that Optionee was not entitled to
exercise the Option at the date of termination, or if Optionee does not exercise
such Option to the extent so entitled within the time specified herein, the
Option shall terminate.

          (e) Rule 16b-3.  Options granted to persons subject to Section 16(b)
              ----------                                                      
of the Exchange Act must comply with Rule 16b-3 and shall contain such
additional conditions or restrictions as may be required thereunder to qualify
for the maximum exemption from Section 16 of the Exchange Act with respect to
Plan transactions.

          (f) Buyout Provisions.  The Administrator may at any time offer to buy
              -----------------                                                 
out for a payment in cash or Shares, an Option previously granted, based on such
terms and conditions as the Administrator shall establish and communicate to the
Optionee at the time that such offer is made.

                                      -8-

 
     10.  Non-Transferability 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 and may be exercised, during the
lifetime of the Optionee, only by the Optionee.

     11.  Stock Purchase Rights.
          --------------------- 

          (a) Rights to Purchase.  Stock Purchase Rights may be issued either
              ------------------                                             
alone, in addition to, or in tandem with other awards granted under the Plan
and/or cash awards made outside of the Plan. After the Administrator determines
that it will offer Stock Purchase Rights under the Plan, it shall advise the
offeree in writing of the terms, conditions and restrictions related to the
offer, including the number of Shares that such person shall be entitled to
purchase, the price to be paid (which price shall not be less than 85% of the
Fair Market Value of the Shares as of the date of the offer), and the time
within which such person must accept such offer, which shall in no event exceed
thirty (30) days from the date upon which the Administrator made the
determination to grant the Stock Purchase Right. The offer shall be accepted by
execution of a Restricted Stock purchase agreement in the form determined by the
Administrator. Shares purchased pursuant to the grant of a Stock Purchase Right
shall be referred to herein as "Restricted Stock."

          (b) Repurchase Option.  Unless the Administrator determines otherwise,
              -----------------                                                 
the Restricted Stock purchase agreement shall grant the Company a repurchase
option exercisable upon the voluntary or involuntary termination of the
purchaser's employment with the Company for any reason (including death or
Disability).  The purchase price for Shares repurchased pursuant to the
Restricted Stock purchase agreement shall be the original price paid by the
purchaser and may be paid by cancellation of any indebtedness of the purchaser
to the Company.  The repurchase option shall lapse at such rate as the Committee
may determine, but in no event at a rate less than 20% per annum. If the
Repurchase Option is assigned by the Company and the Fair market value of the
shares, as determined by the administrator, exceeds the repurchase price, and
such assignee exercises the Repurchase Option, then the assignee shall pay the
Company the difference between the fair market value of the Shares repurchased
and the aggregate repurchase price.

          (c) Other Provisions.  The Restricted Stock purchase agreement shall
              ----------------                                                
contain such other terms, provisions and conditions not inconsistent with the
Plan as may be determined by the Administrator in its sole discretion. In
addition, the provisions of Restricted Stock purchase agreements need not be the
same with respect to each purchaser.

          (d) Rights as a Shareholder.  Once the Stock Purchase Right is
              -----------------------                                   
exercised, the purchaser shall have the rights equivalent to those of a
shareholder, and shall be a shareholder when his or her purchase is entered upon
the records of the duly authorized transfer agent of the Company. No adjustment
will be made for a dividend or other right for which the record date is prior to
the date the Stock Purchase Right is exercised, except as provided in Section 13
of the Plan.

     12.  Stock Withholding to Satisfy Withholding Tax Obligations.  At the
          --------------------------------------------------------         
discretion of the Administrator, Optionees may satisfy withholding obligations
as provided in this paragraph. When an 

                                      -9-

 
Optionee incurs tax liability in connection with an Option or Stock Purchase
Right, which tax liability is subject to tax withholding under applicable tax
laws, and the Optionee is obligated to pay the Company an amount required to be
withheld under applicable tax laws, the Optionee may satisfy the withholding tax
obligation by electing to have the Company withhold from the Shares to be issued
upon exercise of the Option, or the Shares to be issued in connection with the
Stock Purchase Right, if any, that number of Shares having a Fair Market Value
equal to the amount required to be withheld. The Fair Market Value of the Shares
to be withheld shall be determined on the date that the amount of tax to be
withheld is to be determined (the "Tax Date").

     All elections by an Optionee to have Shares withheld for this purpose shall
be made in writing in a form acceptable to the Administrator and shall be
subject to the following restrictions:

          (a) the election must be made on or prior to the applicable Tax Date;

          (b) once made, the election shall be irrevocable as to the particular
Shares of the Option or Right as to which the election is made;

          (c) all elections shall be subject to the consent or disapproval of
the Administrator;

          (d) if the Optionee is subject to Rule 16b-3, the election must comply
with the applicable provisions of Rule 16b-3 and shall be subject to such
additional conditions or restrictions as may be required thereunder to qualify
for the maximum exemption from Section 16 of the Exchange Act with respect to
Plan transactions.

     In the event the election to have Shares withheld is made by an Optionee
and the Tax Date is deferred under Section 83 of the Code because no election is
filed under Section 83(b) of the Code, the Optionee shall receive the full
number of Shares with respect to which the Option or Stock Purchase Right is
exercised but such Optionee shall be unconditionally obligated to tender back to
the Company the proper number of Shares on the Tax Date.

     13.  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 

                                      -10-

 
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 Board shall notify the Optionee at least fifteen (15) days prior to
such proposed action. To the extent it has not been previously exercised, the
Option will terminate immediately prior to the consummation of such proposed
action. In the event of a 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. In the event that such successor corporation does not
agree to assume such Option or to substitute an equivalent option, 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 to the extent that Optionee was
entitled to exercise it upon the expiration of such period, and, to the extent
that Optionee was not entitled to exercise such Option upon the expiration of
such period, or if the Optionee does not exercise such Option to the extent so
entitled within such period, the Option shall terminate. With respect to any
Option granted prior to the July 17, 1992, in the event that such successor
corporation refuses to assume such Option or to substitute an equivalent option,
the Board shall, in lieu of such assumption or substitution, provide for the
Optionee to have the right to exercise such Option as to all of the Optioned
Stock, including Shares as to which the Option would not otherwise be
exercisable. If the Board makes an Option fully exercisable in lieu of
assumption or substitution in the event of a merger, the Board shall notify the
Optionee that such Option shall be fully exercisable for a period of fifteen
(15) days from the date of such notice, and such Option will terminate upon the
expiration of such period.
 
     14.  Time of Granting Options.  The date of grant of an Option shall, for
          ------------------------                                            
all purposes, be the date on which the Administrator makes the determination
granting such Option, or such other date as is determined by the Board.  Notice
of the determination shall be given to each Employee or Consultant to whom an
Option is so granted within a reasonable time after the date of such grant.

     15.  Amendment and Termination of the Plan.
          ------------------------------------- 

          (a) Amendment and Termination.  The Board may at any time amend,
              -------------------------                                   
alter, suspend or discontinue the Plan, but no amendment, alteration, suspension
or discontinuation shall be made which would impair the rights of any Optionee
under any grant theretofore made, without his or her consent.  In addition, to
the extent necessary and desirable to comply with Rule 16b-3 under the Exchange
Act or with Section 422A of the Code (or any other applicable law or regulation,
including the requirements of the NASD or an established stock exchange), the
Company shall obtain shareholder approval of any Plan amendment in such a manner
and to such a degree as required.

          (b) Effect of Amendment or Termination.  Any such amendment or
              ----------------------------------                        
termination of the Plan shall not affect Options already granted 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 

                                      -11-

 
Optionee and the Board, which agreement must be in writing and signed by the
Optionee and the Company.

     16.  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, 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.

     17.  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.

          The 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.

     18.  Agreements.  Options and Stock Purchase Rights shall be evidenced by
          ----------                                                          
written agreements in such form as the Board shall approve from time to time.

     19.  Shareholder Approval.  Continuance of the Plan shall be subject to
          --------------------                                              
approval by the shareholders of the Company within twelve (12) months before or
after the date the Plan is adopted. Such shareholder approval shall be obtained
in the degree and manner required under applicable state and federal law.

     20.  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 and other information which are provided to all
shareholders of the Company. The Company shall not be required to provide such
information if the issuance of Options under the Plan is limited to key
employees whose duties in connection with the Company assure their access to
equivalent information.

                                      -12-