EMPLOYMENT AGREEMENT FOR EXECUTIVE OFFICER


     EMPLOYMENT AGREEMENT FOR EXECUTIVE OFFICER ("Agreement") made as of the 
1st day of November, 1996, between STB SYSTEMS, INC., a Texas corporation 
(the "Company"), and J. SHANE LONG ("Executive").

     WHEREAS, Executive possesses an intimate knowledge of the business and 
affairs of the Company, its policies, methods, personnel, and plans for the 
future;

     WHEREAS, the Board of Directors of the Company (the "Board") recognizes 
that Executive's contribution as Vice President, Sales and Marketing to the 
growth and success of the Company has been substantial and desires to assure 
the Company of Executive's continued employment in an executive capacity and 
to compensate him therefor; and

     WHEREAS, Executive is desirous of committing himself to serve the 
Company on the terms herein provided.

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

1.   EMPLOYMENT.  The Company hereby agrees to continue to employ Executive 
and Executive hereby agrees to continue to serve the Company, on the terms 
and conditions set forth herein, for the period commencing on the date hereof 
and expiring on October 31, 1997 (unless sooner terminated as hereinafter set 
forth); provided, however, that commencing on October 31, 1997, and each 
October 31 thereafter, the term of this Agreement shall automatically be 
extended for one additional year unless, at least 30 days prior to any such 
October 31, the Company or Executive shall have given notice that it does not 
wish to extend this Agreement.  The term of this Agreement, as it may from 
time to time be extended in accordance with this Paragraph, may be referred 
to herein as the "Period of Employment".

2.   POSITION AND DUTIES.  Executive shall serve as the Vice President, Sales 
& Marketing, of the Company performing the functions and duties as shall be 
prescribed from time to time provided that such functions and duties are 
consistent with and attendant to Executive's position or other positions that 
he may hold from time to time.  Executive shall devote his full working time 
and efforts to the business and affairs of the Company and the promotion of 
its interests and perform all duties and services on behalf of the Company 
necessary to carry out such functions.

3.   COMPENSATION AND RELATED MATTERS.

     (a)  BASE SALARY.  Initially, Executive shall receive an annual base salary
     ("Base Salary") at the rate of One Hundred Sixty Thousand Dollars and
     No/100 Cents ($160,000.00) during the period ending October 31, 1997. 
     Thereafter, Executive's Base Salary shall be redetermined at least 30 days
     before each October 31 in an 




     amount to be fixed by the Compensation Committee.  The term "Base 
     Salary" as used in this Agreement shall mean, at any point in time, 
     Executive's annual base salary at such time.  The Base Salary shall be 
     payable in substantially equal semi-monthly installments and shall in 
     no way limit or reduce the obligations of the Company hereunder.
     
     (b)  INCENTIVE COMPENSATION.  In addition to Base Salary, Executive is
     eligible to receive incentive compensation in accordance with the Company's
     Profit Sharing Incentive Plan.

     (c)  SALES COMMISSIONS.  In addition to Base Salary and Incentive
     Compensation, Executive shall receive sales commissions that shall be
     payable monthly on the fifteenth of the month following the month in which
     they are earned.  For each period beginning November 1 and ending October
     31, the Chief Executive Officer shall recommend and the Compensation
     Committee shall approve the formula to be used to calculate sales
     commissions.

     (d)  EXPENSES.  During any Period of Employment, Executive shall be
     entitled to receive prompt reimbursement for all reasonable expenses
     incurred by him (in accordance with the policies and procedures then in
     effect and established by the Company for its senior executive officers) in
     performing services hereunder, provided that Executive properly accounts
     therefor in accordance with Company policy.

     (e)  OTHER BENEFITS.  Executive shall be entitled to continue to
     participate in or receive benefits under all of the Company's Employee
     Benefit Plans in effect on the date hereof, or under plans or arrangements
     that provide Executive with at least substantially equivalent benefits to
     those provided under such Employee Benefit Plans.  As used herein,
     "Employee Benefit Plans" include, without limitation, each pension, and
     retirement plan; supplemental pension, retirement, and deferred
     compensation plan; savings and profit sharing plan; stock ownership plan;
     stock purchase plan; stock option plan; life insurance plan; medical
     insurance plan; disability plan; and health and accident plan or
     arrangement established and maintained by the Company on the date hereof. 
     Executive shall be entitled to participate in or receive benefits under any
     employee benefit plan or arrangement which may, in the future, be made
     available by the Company to its executives and key management employees,
     subject to and on a basis consistent with the terms, conditions, and
     overall administration of such plan or arrangement.  Nothing paid to
     Executive under the Employee Benefit Plans presently in effect or any
     employee benefit plan or arrangement which may be made available in the
     future shall be deemed to be in lieu of compensation payable to Executive
     under Subparagraphs 3(a), 3(b), and 3(c).  Any payments or benefits payable
     to Executive under a plan or arrangement referred to in this Subparagraph
     3(e) in respect of any calendar year during which Executive is employed by
     the Company for less than the whole of such year shall, unless otherwise
     provided in the applicable plan or arrangement, be 

                                      -2-




     prorated in accordance with the number of days in such calendar year 
     during which he is so employed.  Should any such payments or benefits 
     accrue on a fiscal (rather than calendar) year, then the proration in 
     the preceding sentence shall be on the basis of a fiscal year rather 
     than calendar year.
     
     (f)  VACATIONS.  Executive shall be entitled to the number of paid vacation
     days in each calendar year determined by the Company from time to time for
     its senior executive officers.  Executive shall also be entitled to all
     paid holidays given by the Company to its senior executive officers.

4.   OFFICES.  Executive agrees to serve as a director of the Company, if
elected or appointed thereto, provided he is indemnified for serving in such
capacity on a basis no less favorable than is currently provided by the
Company's By-laws.

5.   CONFIDENTIAL INFORMATION.  Executive acknowledges that in the course of his
employment with the Company, he will gain a close, personal and special
influence with the Company's customers and will be acquainted with the Company's
business affairs, information, trade secrets, and other matters which are of a
proprietary or confidential nature, including but not limited to the Company's
operations, business opportunities, price and cost information, finances,
customer names, prospects and customer lists, business plans, various sales
techniques, manuals, letters, notebooks, procedures, reports, products,
processes, services, inventions, research and development, and other
confidential information and knowledge (collectively, "Confidential
Information") concerning the Company's business.  The term "Confidential
Information" shall not include information which (a) is or becomes generally
available to the public through no violation of this Agreement, (b) was
available to Executive on a nonconfidential basis prior to disclosure to
Executive by the Company, or (c) becomes available to Executive on a
nonconfidential basis from a source other than the Company, provided that such
source is not bound by a confidentiality agreement with the Company.  The
Company agrees to provide such Confidential Information and/or training which
the Company deems necessary or desirable to aid Executive in the performance of
his duties.  Executive understands and acknowledges that such Confidential
Information is confidential, and he agrees not to disclose such Confidential
Information to anyone outside the Company.  Executive further agrees that he
will not during employment and/or at any time thereafter use such Confidential
Information in competing, directly or indirectly, with the Company.  At such
time as Executive shall cease to be employed by the Company, he will immediately
turn over to the Company all such Confidential Information including papers,
documents, writings, electronically stored information, other property, and all
copies of them provided to him during the course of his employment with the
Company.  During or upon termination, for any reason, of Executive's employment
with the Company, Executive shall sign a list acknowledging the Confidential
Information of which he has gained knowledge or information during the course of
his employment with the Company.  The obligations of this Paragraph 5 shall
continue beyond the termination of Executive's employment, regardless of the
reason for such termination, and shall be binding upon Executive's assigns,
executors, administrators, and other legal representatives.

                                      -3-




6.   CONFLICT OF INTEREST.  In keeping with Executive's fiduciary duties to the
Company, Executive agrees that while employed by the Company he shall not,
acting alone or in conjunction with others, directly or indirectly, become
involved in a conflict of interest or, upon discovery thereof, allow such a
conflict to continue.  Moreover, Executive agrees that he shall immediately
disclose to the Company any facts which might involve any reasonable possibility
of a conflict of interest.  It is agreed that any direct or indirect interest,
connection with, or benefit from any outside activities, where such interest
might in any way adversely affect the Company, involves a possible conflict of
interest.  Circumstances in which a conflict of interest on the part of
Executive might arise, and which must be reported immediately by Executive to
the Company, include, but are not limited to, the following: (a) ownership of a
material interest in any supplier, contractor, subcontractor, customer, or other
entity with which the Company does business; (b) acting in any capacity,
including director, officer, partner, consultant, employee, distributor, agent,
or the like for a supplier, contractor, subcontractor, customer, or other entity
with which the Company does business; (c) accepting, directly or indirectly,
payment, service, or loans from a supplier, contractor, subcontractor, customer,
or other entity with which the Company does business, including, but not limited
to, gifts, trips, entertainment, or other favors of more than a nominal value;
(d) misuse of the Company's information or facilities to which Executive has
access in a manner which will be detrimental to the Company's interest, such as
utilization for Executive's own benefit of know-how, inventions, or information
developed through the Company's business activities; (e) disclosure or other
misuse of Confidential Information of any kind obtained through Executive's
connection with the Company; (f) appropriation by Executive or the diversion to
others, directly or indirectly, of any business opportunity in which it is known
or could reasonably be anticipated that the Company would be interested; and (g)
the ownership, directly or indirectly, of a material interest in an enterprise
in competition with the Company, or acting as an owner, director, principal,
officer, partner, consultant, employee, agent, servant, or otherwise of any
enterprise which is in competition with the Company.

7.   PROPRIETARY INFORMATION.  Executive agrees to promptly and freely disclose
to the Company in writing any and all ideas, conceptions, inventions,
improvements, suggestions for improvements, discoveries, formulae, processes,
designs, software, firmware, hardware, circuitry, diagrams, copyrights, trade
secrets, and any other proprietary information (collectively, the "Proprietary
Information"), whether patentable or not, which are conceived, and made or
acquired by Executive solely or jointly with others during the period of his
employment by the Company or using the Company's time, data, facilities, and/or
materials, and which are related to the products, business, or activities of the
Company which Executive conceives as a result of his employment by the Company,
and Executive agrees to assign and hereby does assign all of his interest
therein to the Company, or its nominee.  Whenever requested to do so by the
Company, Executive shall execute any and all applications, assignments, or other
instruments, which the Company shall deem necessary to apply for and obtain
Letters Patent or Copyrights of the United States, or any foreign country, to
otherwise protect the Company's interest in the Proprietary Information or to
vest title to the Proprietary Information in the Company.  These obligations
shall continue 

                                      -4-




beyond the termination of Executive's employment, regardless of the reason 
for such termination, with respect to the Proprietary Information, conceived, 
and made or acquired by Executive during the period of his employment and 
shall be binding upon Executive's assigns, executors, administrators, and 
other legal representatives.

8.   COVENANT NOT TO COMPETE.

     (a)  In consideration for Executive's employment by the Company under the
     terms provided in this Agreement and as a means to aid in the performance
     and enforcement of the terms of the Confidential Information, Conflict of
     Interest, and Proprietary Information provisions (Paragraphs 5, 6, and 7),
     Executive agrees that 

         (i)   during his employment with the Company and for a period of two
               years commencing from the Date of Termination (as defined in
               Paragraph 9), Executive will not, directly or indirectly, as an
               owner, director, principal, agent, officer, employee, partner,
               consultant, servant, or otherwise, carry on, operate, manage,
               control, or become involved in any manner with any business,
               operation, corporation, partnership, association, agency, or
               other person or entity that (A) is located in North America or
               Europe and (B) derives at least 51 percent of its gross revenue
               from developing, manufacturing, or selling graphics adapters for
               desktop personal computers or from any other business in which
               the Company is engaged on Executive's Date of Termination;

         (ii)  during his employment with the Company and for a period of two
               years commencing from the Date of Termination, Executive will
               not, directly or indirectly, either for himself or for any other
               business, operation, corporation, partnership, association,
               agency, or other person or entity, call upon, compete for,
               solicit, divert, or take away, or attempt to divert or take away
               any of the Company's customers in North America and Europe; and

         (iii) during his employment with the Company and for a period of
               two years commencing from the Date of Termination, Executive
               will not, directly or indirectly, cause or induce any
               present or future employee of the Company to accept
               employment with Executive or with any business, operation,
               corporation, partnership, association, agency, or other
               person or entity with which Executive may be associated.

     (b)  If Executive is entitled to receive the Parachute Payment Amount under
     Paragraph 11, then the provisions of Subparagraph 8(a) shall not apply.

                                      -5-




     (c)  Any alleged breach of other provisions of this Agreement asserted by
     Executive will not be a defense to claims arising from the Company's
     enforcement of the provisions of this Paragraph 8.

     (d)  Should Executive violate the provisions of this Paragraph 8, then the
     period of time for this covenant shall automatically be extended for the
     period of time from which Executive began such violation until he
     permanently ceases such violation.

9.   TERMINATION.  Executive's employment hereunder may be terminated without
any breach of this Agreement under the following circumstances:

     (a)  DEATH.  Executive's employment hereunder shall terminate upon his
     death. 

     (b)  DISABILITY.  If, as a result of Executive's incapacity due to illness,
     accident, or other physical or mental incapacity, Executive shall have been
     absent from his duties hereunder on a full-time basis for 180 calendar days
     in the aggregate in any 12-month period, the Company may terminate
     Executive's employment hereunder.

     (c)  CAUSE.  The Company may terminate Executive's employment hereunder for
     Cause.  For purposes of this Agreement, the Company shall have "Cause" to
     terminate Executive's employment hereunder upon:  (A) the willful and
     continued failure by Executive to perform substantially his duties
     consistent with this Agreement (other than any such failure resulting from
     Executive's incapacity due to physical or mental illness) after notice
     demanding substantial performance is delivered by the Company to Executive
     specifically identifying the manner in which the Company believes Executive
     has not substantially performed his duties and Executive has not cured such
     demands within 30 days after receipt of such notice; (B) the willful
     engaging by Executive in misconduct which is injurious to the Company,
     monetarily or otherwise; (C) the willful violation by Executive of the
     provisions of Paragraphs 5, 6, or 7; (D) the willful, persistent failure or
     refusal by Executive to follow reasonable policies, standards, directives,
     or orders established by the Company; or (E) the conviction of or guilty
     plea by Executive of a crime of moral turpitude or other felony including
     without limitation fraud, theft, or embezzlement.  For purposes of this
     Subparagraph 9(c), no act, or failure to act, on Executive's part shall be
     considered "willful" unless done or omitted to be done by him not in good
     faith and without reasonable belief that his action or omission was in the
     best interest of the Company.  Notwithstanding the foregoing, Executive
     shall not be deemed to have been terminated for Cause unless and until
     there shall have been delivered to Executive a copy of a resolution, duly
     adopted by the affirmative vote of not less than three-quarters (3/4) of
     the entire membership of the Board at a meeting of the Board called and
     held for such purposes (after reasonable notice to Executive and an
     opportunity for him, together with his counsel, to be heard before the
     Board), finding that in the good faith opinion of the Board, Executive was
     guilty of conduct set forth above in clause (A), (B), (C), (D), or (E) of
     this subparagraph.

                                      -6-




     (d)  TERMINATION BY EXECUTIVE.  Executive may, during the Period of
     Employment, upon giving Notice of Termination, terminate his employment
     hereunder (i) for Good Reason or (ii) if his health should become impaired
     to such an extent that the continued performance of his duties hereunder is
     hazardous to his physical or mental health or his life, provided that
     Executive shall have furnished the Company with a written statement from a
     qualified doctor to such effect.

     For purposes of this Agreement, "Good Reason" shall mean: (A) without
     Executive's consent, an assignment to Executive of duties, or a material
     limitation of the scope of Executive's duties or powers, materially
     inconsistent with his designated position and not contemplated by Paragraph
     2; (B) without Executive's consent, a removal, during the Period of
     Employment, of Executive from or, with respect to a term ending prior to
     the end of the Period of Employment, any failure by management to nominate,
     or, if nominated by the shareholders, to re-elect, Executive to any of the
     positions indicated in Paragraph 2, except in connection with termination
     of Executive's employment for Cause, death, or disability; (C) without
     Executive's consent, a reduction of Executive's Base Salary to an amount
     less than previously determined and fixed by the Compensation Committee in
     accordance with Subparagraph 3(a) other than a reduction deemed necessary
     by the Board for all executive officers; or (D) breach by the Company of
     any of its material obligations under this Agreement and such breach is not
     cured within 30 days after written notice thereof by Executive.

     (e)  NOTICE OF TERMINATION.  Except for terminations specified in
     Subparagraphs 9(a) and 9(h), any termination during the Period of
     Employment of Executive's employment by the Company or any such termination
     by Executive shall be communicated by written Notice of Termination to the
     other party hereto. For purposes of this Agreement, a "Notice of
     Termination" shall mean a notice which shall indicate the specific
     termination provision in this Agreement relied upon and shall set forth in
     reasonable detail the facts and circumstances claimed to provide a basis
     for termination of Executive's employment under the provision so indicated.

     (f)  DATE OF TERMINATION. "Date of Termination" shall, during the Period of
     Employment, mean: (i) if Executive's employment is terminated by his death,
     the date of his death; (ii) if Executive's employment is terminated on
     account of disability under Subparagraph 9(b), the date on which Notice of
     Termination is given; (iii) if Executive's employment is terminated by the
     Company for Cause under Subparagraph 9(c), the date specified in the Notice
     of Termination; (iv) if Executive's employment is terminated by the
     expiration of the Period of Employment under Subparagraph 9(h), the date of
     such expiration; and (v) if Executive's employment is terminated for any
     other reason, subject to the provisions of Subparagraphs 9(g) and 10(d) and
     Paragraph 11 to the contrary, the date on which a Notice of Termination is
     given.

                                      -7-




     (g)  RETIREMENT.  Notwithstanding any other provision hereof to the
     contrary, Executive may, at any time during the Period of Employment, upon
     the giving of 90 days Notice of Termination, terminate his employment
     hereunder, if Executive is then permitted to retire under the provisions of
     the Company's pension plan then in effect.  The Date of Termination in
     event of such Retirement shall be 90 days after such Notice of Termination
     but in no case shall it exceed the Period of Employment.

     (h)  EXPIRATION OF AGREEMENT.  Executive's employment hereunder shall
     terminate at the expiration of the Period of Employment as provided in
     Paragraph 1.

10.  COMPENSATION UPON TERMINATION OR DURING DISABILITY.

     (a)  If Executive's employment terminates by reason of his death, the
     Company shall, within 90 days of death, pay in a lump sum amount to such
     person as Executive shall designate in a notice filed with the Company or,
     if no such person is designated, to Executive's estate, Executive's accrued
     and unpaid Base Salary to the date of his death, plus his accrued and
     unpaid incentive compensation under Subparagraph 3(b), if any, plus his
     accrued and unpaid sales commissions under Subparagraph 3(c), if any.  In
     addition to the foregoing, any payments to which Executive's spouse,
     beneficiaries, or estate may be entitled to receive under any employee
     benefit plan shall also be paid in accordance with the terms of such plan
     or arrangement.  Such payments, in the aggregate, shall fully discharge the
     Company's obligations hereunder.

     (b)  During any period that Executive fails to perform his duties hereunder
     as a result of incapacity due to physical or mental illness, Executive
     shall continue to receive his accrued and unpaid Base Salary and accrued
     and unpaid incentive compensation payments under Subparagraph 3(b), if any,
     and accrued and unpaid sales commissions under Subparagraph 3(c), if any,
     until Executive's employment is terminated due to disability in accordance
     with Subparagraph 9(b) or until Executive terminates his employment in
     accordance with Subparagraph 9(d)(ii), whichever first occurs.  Upon
     termination due to death prior to the termination first to occur as
     specified in the preceding sentence, Subparagraph 10(a) shall apply.

     (c)  If Executive's employment is terminated for Cause, the Company shall,
     through the Date of Termination, pay Executive his accrued and unpaid Base
     Salary at the rate in effect at the time Notice of Termination is given and
     his accrued and unpaid incentive compensation under Subparagraph 3(b), if
     any, and his accrued and unpaid sales commissions under Subparagraph 3(c),
     if any, and thereafter, the Company shall have no further obligations to
     Executive under this Agreement; provided, any such termination for Cause
     shall not adversely affect or alter Executive's rights under any employee
     benefit plan of the Company in which Executive, at the Date of Termination,
     has a vested interest.

                                      -8-




     (d)  If (A) the Company terminates Executive's employment other than in
     accordance with Subparagraph 9(a), 9(b), or 9(c) (it being understood that
     a purported termination under Subparagraph 9(c) which is disputed and
     finally determined not to have been proper shall be a termination by the
     Company in material breach of this Agreement), or (B) Executive shall
     terminate his employment for Good Reason, or (C) the Company gives
     Executive notice that it does not wish to extend this Agreement in
     accordance with Paragraph 1, then

         (i)   the Company shall, through the Date of Termination, pay Executive
               his accrued and unpaid Base Salary at the rate in effect at the
               time Notice of Termination is given and his accrued and unpaid
               incentive compensation under Subparagraph 3(b), if any, and his
               accrued and unpaid sales commissions under Subparagraph 3(c), if
               any;

         (ii)  in lieu of any further payments to or claims by Executive for
               payments of salary or incentive compensation for periods
               subsequent to the Date of Termination, the Company shall pay to
               Executive a Severance Payment Amount equal to the sum of (1)
               Executive's Base Salary, (2) Executive's annualized incentive
               compensation under Subparagraph 3(b), and (3) Executive's
               annualized sales commissions under Subparagraph 3(c).  For
               purposes of calculating the Severance Payment Amount, Executive's
               Base Salary will be equal to Executive's then-current Base Salary
               (provided, however, that if the basis for  Executive's
               termination is for Good Reason under clause (C) of Subparagraph
               9(d), the Severance Payment Amount shall be based on the Base
               Salary in effect prior to such reduction); the annualized
               incentive compensation will be four times the average of the
               amount of incentive compensation earned in the eight full
               quarters preceding the earlier of the Notice of Termination or
               Date of Termination; and the annualized sales commissions will be
               12 times the average of the amount of sales commissions earned in
               the 24 full months preceding the earlier of the Notice of
               Termination or Date of Termination.  The Company shall pay
               Executive the Severance Payment Amount in one lump sum on the
               thirtieth day following the Date of Termination.

         (iii) Executive shall receive all the rights and benefits granted
               or in effect with respect to Executive under the Company's
               qualified and nonqualified stock option plans and agreements
               with Executive pursuant thereto; and

         (iv)  Executive shall receive payments made in lieu of accrued and
               unused vacation as provided for in the Company's vacation
               policies.  Notwithstanding the foregoing, if Executive terminates
               his employment for Good Reason, he shall be entitled to severance
               pay under 

                                      -9-





               Subparagraph 10(d)(ii) if he gives a Notice of Termination 
               in accordance with Subparagraph 9(e) within 30 days after 
               the occurrence of the event or events specified in clauses
               (A), (B), (C), and (D) of Subparagraph 9(d).

     (e)  If Executive's employment shall be terminated by reason of retirement
     under Subparagraph 9(g) or if Executive gives the Company notice that he
     does not wish to extend this Agreement in accordance with Paragraph 1, the
     Company shall have no further obligations hereunder except for continuing
     obligations arising under Subparagraphs 3(d) and 9(g).

     (f)  Nothing contained in the foregoing Subparagraphs 10(a) through 10(e)
     shall be construed so as to affect the Executive's rights or the Company's
     obligations relating to agreements or benefits which are unrelated to
     termination of employment.

11.  PARACHUTE PAYMENT AGREEMENT.  The provisions of this Paragraph 11 of the
Agreement set forth certain terms of an agreement reached between Executive and
the Company regarding Executive's rights and obligations upon the occurrence of
a Change in Control of the Company.  These provisions are intended to assure and
encourage in advance Executive's continued attention and dedication to his
assigned duties and his objectivity during the pendency and after the occurrence
of any such event. These provisions shall apply in lieu of, and expressly
supersede, the provisions of Subparagraph 10(d)(ii) regarding severance pay upon
a termination of employment, if such termination of employment occurs within 12
months after the occurrence of the first event constituting a Change of Control.
These provisions shall terminate and be of no further force or effect 12 months
after the occurrence of a Change of Control.

     (a)  POTENTIAL CHANGE IN CONTROL.  Subject to the terms and conditions of
     this Agreement, in the event of a Potential Change in Control, Executive
     shall remain in the employ of the Company until the earliest of (i) a date
     which is six months from the occurrence of such Potential Change in
     Control; (ii) the Executive's death; (iii) the termination of his
     employment by reason of his inability, due to illness, accident, or other
     physical or mental incapacity, to perform his duties for more than 180 days
     during any 12-month period; (iv) the termination by the Company for Cause;
     or (v) the occurrence of a Change in Control.

     (b)  CHANGE IN CONTROL.  If, within 12 months after the occurrence of the
     first event constituting a Change in Control, Executive's employment
     terminates for any reason other than (i) death, (ii) termination by the
     Company for Cause, (iii) his inability, due to illness, accident, or other
     physical or mental incapacity, to perform his duties for more than 180 days
     during any 12-month period, or (iv) his Voluntary Resignation, the Company
     shall pay Executive an amount equal to the applicable Parachute Payment
     Amount in a lump sum on the thirtieth day following Executive's
     termination.

                                      -10-




     (c)  DEFINITIONS.  For purposes of this Section 11 and this Agreement, the
     following terms shall have the following meanings:

          "CHANGE IN CONTROL" shall mean an event which shall be deemed to have
     occurred if (i) a merger or consolidation of the Company with or into
     another corporation occurs in which the Company shall not be the surviving
     corporation (for purposes of this definition, the Company shall not be
     deemed the surviving corporation in any such transaction if, as the result
     thereof, it becomes a wholly-owned subsidiary of another corporation); (ii)
     a dissolution of the Company occurs; (iii) a transfer of all or
     substantially all of the assets or shares of stock of the Company in one
     transaction or a series of related transactions to one or more other
     persons or entities occurs; (iv) if any "person" or "group" as those terms
     are used in Sections 13(d) and 14(d) of the Securities Exchange Act of
     1934, as amended (the "Act"), other than Excluded Persons, becomes the
     "beneficial owner" (as defined in Rule 13d-3 of the Act), directly or
     indirectly, of securities of the Company representing 50% or more of the
     combined voting power of the Company's then outstanding securities; or (v)
     during any period of two consecutive years commencing on or after April 1,
     1995, individuals who at the beginning of the period constituted the Board
     cease for any reason to constitute at least a majority, unless the election
     of each director who was not a director at the beginning of the period has
     been approved in advance by directors representing at least two-thirds
     (2/3) of the directors then in office who were directors at the beginning
     of the period.  The term "Excluded Persons" means each of William E. Ogle,
     William D. Balthaser, Jr., and Mark S. Sims, and any person, entity, or
     group under the control of any of them, or a trustee or other fiduciary
     holding securities under an employee benefit plan of the Company.

          "COMPANY" shall mean not only STB Systems, Inc., but also its
     successors by merger or otherwise.

          "PARACHUTE PAYMENT AMOUNT" shall mean an amount equal to two times the
     Severance Payment Amount payable under Subparagraph 10(d)(ii).

          "POTENTIAL CHANGE IN CONTROL" shall mean an event which shall be
     deemed to have occurred if (i) the Company enters into an agreement, the
     consummation of which would result in the occurrence of a Change in
     Control; (ii) any person (including the Company) publicly announces an
     intention to take or to consider taking actions which if consummated would
     constitute a Change in Control; (iii) any person" or "group" as those terms
     are used in Section 13(d) and l4(d) of the Securities Exchange Act of 1934,
     as amended (the "Act"), other than Excluded Persons, who is or becomes the
     "beneficial owner" (as defined in Rule 13d-3 of the Act), directly or
     indirectly, of securities of the Company representing 10% or more of the
     combined voting power of the Company's then outstanding securities,
     increases his beneficial ownership of such securities by 5% or more over
     the percentage so 

                                      -11-




     owned by such person on the date hereof; or (iv) the Board adopts a
     resolution to the effect that, for purposes of this Agreement, a 
     Potential Change in Control of the Company has occurred.  The
     term "Excluded Persons" means each of William E. Ogle, William D.
     Balthaser, Jr., and Mark S. Sims, and any person, entity, or group under
     the control of any of them, or a trustee or other fiduciary holding
     securities under an employee benefit plan of the Company.

          "VOLUNTARY RESIGNATION" shall mean any termination of Executive's
     employment by his own act, unless such termination follows any change in
     his position with the Company to a position of lesser authority, any
     material changes in his duties, any reduction in his Base Salary or
     incentive compensation, any material reduction of his employee benefits,
     any material increase in the frequency of his travel, or any change in the
     circumstances of his employment which, in Executive's good faith judgment,
     results in his being unable to carry out the duties, authority, or powers
     attached to his position; provided that such change, reduction, or increase
     occurs after the occurrence of a Change in Control, and provided further
     that any sale of assets of the Company that constitute less than 25% of the
     Company's assets and less than 25% of the Company's annual revenues for the
     preceding fiscal year shall not result in a change in the circumstances of
     Executive's employment with the Company.

12.  NOTICE.  For purposes of this Agreement, notices and all other
communications provided for in the Agreement shall be in writing and shall be
deemed to have been duly given when delivered or mailed by United States
certified mail, return receipt requested, postage prepaid, addressed as follows:

                    if to the Executive:

                         At his home address as shown
                         in the Company's personnel records;

                    if to the Company:

                         STB Systems, Inc.
                         1651 North Glenville Drive, Suite 210
                         Richardson, Texas 75081
                         Attn: Secretary

or to such other address as either party may have furnished to the other in
writing in accordance herewith, except that notices of change of address shall
be effective only upon receipt.

13.  MISCELLANEOUS.  No provisions of this Agreement may be modified, waived, or
discharged unless such waiver, modification, or discharge is agreed to in
writing and signed by the Executive and such officer of the Company as may be
specifically designated by the 

                                      -12-





Board.  No waiver by either party hereto of, or compliance with, any 
condition or provision of this Agreement to be performed by such other party 
shall be deemed a waiver of similar or dissimilar provisions or conditions at 
the same or at any prior or subsequent time.  No agreements or 
representations, oral or otherwise, express or implied, unless specifically 
referred to herein, with respect to the subject matter hereof have been made 
by either party which are not set forth expressly in this Agreement.  The 
validity, interpretation, construction, and performance of this Agreement 
shall be governed by the laws of the State of Texas.

14.  VALIDITY.  The invalidity or unenforceability of any provision or
provisions of this Agreement shall not affect the validity or enforceability of
any other provision of this Agreement, which shall remain in full force and
effect.  The invalid portion of this Agreement, if any, shall be modified by any
court having jurisdiction to the extent necessary to render such portion
enforceable.

15.  COUNTERPARTS.  This Agreement may be executed in several counterparts, each
of which shall be deemed to be an original but all of which together will
constitute one and the same instrument.

16.  ARBITRATION.  Any dispute or controversy arising under or in connection
with this Agreement shall be settled exclusively by arbitration in Dallas,
Texas, in accordance with the rules of the American Arbitration Association then
in effect.  Judgment may be entered on the arbitrator's award in any court
having jurisdiction.  Notwithstanding the above, the Company shall be entitled
to seek a restraining order or injunction in any court of competent jurisdiction
to prevent any continuation of any violation of Paragraphs 5, 6, 7, or 8; and
Executive shall be entitled to seek a restraining order or injunction in any
court of competent jurisdiction to prevent enforcement of Paragraphs 5, 6, 7, or
8. Furthermore, should a dispute occur concerning Executive's mental or physical
capacity as described in Subparagraphs 9(b) or 9(d), the procedure to resolve
the dispute solely as to this mental or physical condition shall be that
described in Subparagraph 9(d), except that a doctor selected by the Company
shall also be entitled to examine Executive.  If the opinion of the Company's
doctor and Executive's doctor conflict, the Company's doctor and Executive's
doctor shall together agree upon a third doctor, whose opinion shall be binding.

     IN WITNESS WHEREOF, the parties have executed this Agreement effective on
the date and year written above.

                                   STB SYSTEMS, INC


/s/ J. SHANE LONG                  /s/ WILLIAM E. OGLE
- ----------------------------       ----------------------------
J. SHANE LONG                      By:  William E. Ogle
                                      -------------------------
                                   Its: President
                                       ------------------------

                                   -13-