<PAGE>


                                  EXHIBIT 10.19

                              SEPARATION AGREEMENT


                         EMPLOYMENT SEPARATION AGREEMENT


       THIS EMPLOYMENT SEPARATION AGREEMENT (the "Agreement"), which includes
Exhibits A and B which are incorporated by this reference, is entered into by
and between GTSI CORP., a Delaware corporation ("GTSI"), and JOEL A. LIPKIN
("Former Employee"). It will become effective as set forth in Section 14.18 (the
"Effective Date").

                                    RECITALS

       A.  Former Employee ceased to be an employee and officer of GTSI on
October 4, 2001 (the "Termination Date").

       B.  Former Employee desires to receive the benefits set forth in this
Agreement. Former Employee's receipt of these benefits is contingent upon Former
Employee's entering into this Agreement and undertaking the obligations it sets
forth.

       C.  GTSI and Former Employee desire to set forth their respective rights
and obligations with respect to Former Employee's separation from GTSI and to
settle and resolve all matters concerning Former Employee's past services to
GTSI.

                                    AGREEMENT

       NOW, THEREFORE, in consideration of the foregoing recitals and the mutual
covenants and conditions in this agreement, the receipt and sufficiency of which
are hereby acknowledged, GTSI and Former Employee agree as follows:

1.     DEFINITIONS

       The following terms shall have the meanings set forth below:

       1.1 "INCLUDES;" "INCLUDING." Except where followed directly by the word
"only," the terms "includes" or "including" shall mean "includes, but is not
limited to," and "including, but not limited to," respectively.

       1.2 "SEPARATION PERIOD." The term "Separation Period" shall mean the six
months immediately following the Termination Date.

2.     MUTUAL REPRESENTATIONS, WARRANTIES AND COVENANTS

       Each party represents, warrants and covenants (with respect to
itself/himself only) to the other party that, to its/his respective best
knowledge and belief as of the date of each party's respective signature below:

       2.1 FULL POWER AND AUTHORITY. It/he has full power and authority to
execute, enter into and perform its/his obligations under this Agreement; this
Agreement, after execution by both parties, will be


                                       1
<PAGE>

a legal, valid and binding obligation of such party enforceable against it/him
in accordance with its terms; it/he will not act or omit to act in any way which
would materially interfere with or prohibit the performance of any of its/his
obligations hereunder, and no approval or consent other than as has been
obtained of any other party is necessary in connection with the execution and
performance of this Agreement.

       2.2 EFFECT OF AGREEMENT. The execution, delivery and performance of this
Agreement and the consummation of the transactions it contemplates:

           (a)  will not interfere or conflict with, result in a breach of,
constitute a default under or violation of any of the terms, provisions,
covenants or conditions of any contract, agreement or understanding, whether
written or oral, to which either party is a party (including, in the case of
GTSI, its bylaws and articles of incorporation as amended to date) or to which
it/he is bound; and

           (b)  will not conflict with or violate any applicable law, rule,
regulation, judgment, order or decree of any government, governmental agency or
court having jurisdiction of such party.


3.     CONFIDENTIALITY OBLIGATIONS DO NOT TERMINATE

       Former Employee acknowledges that any confidentiality, proprietary rights
or nondisclosure agreement(s) in favor of GTSI which he may have entered into in
connection with his employment (the "Nondisclosure Agreement") with GTSI will
survive any termination of such employment, and nothing in this Agreement shall
be construed as terminating, limiting or otherwise affecting any such
Nondisclosure Agreement(s) or Former Employee's obligations thereunder. Without
limiting the generality of the foregoing, no time period set forth in this
Agreement shall shorten or limit the term of any such Nondisclosure
Agreement(s), which term shall continue as set forth therein.

4.     COMPANY PROPERTY

       On or before the effective date, Former Employee agrees to return to GTSI
any and all GTSI assets or property which have come into his possession or
control.


5.     STOCK OPTIONS

       Exhibit A sets forth a complete list of any and all stock options,
warrants and other rights to purchase capital stock of GTSI which have been
previously issued to Former Employee and which have vested as of the date
hereof. This list includes certain additional options over and above those which
had vested as of the date of this Agreement. As consideration to Former Employee
under this Agreement these additional options will vest as of the Effective
Date. All other outstanding stock options granted to Former Employee will
immediately expire upon the Effective Date.

6.     PURCHASE OF STOCK BY GTSI

       Promptly after the Effective Date referred to in Section 14.18 below,
Former Employee will exercise all of his options to purchase capital stock of
GTSI, as listed on Exhibit A, and will then concurrently transfer good and
merchantable title to all of such capital stock back to GTSI, free and clear of
any liens, rights or claims of third parties, at a price of $6.25 per share.
Upon receipt of clear title to the above capitol stock, GTSI will promptly
complete the purchase and issue to Former Employee payment of the net proceeds
from such transactions.

                                       2
<PAGE>

7.     CONFIDENTIAL INFORMATION AND TRADE SECRETS

       7.1 Former Employee recognizes, acknowledges and agrees that GTSI is the
owner of proprietary rights in certain confidential sales and marketing
information, programs, tactics, systems, methods, processes, compilations of
technical and non-technical information, records and other business, financial,
sales, marketing and other information and things of value. To the extent that
any or all of the foregoing constitute valuable trade secrets and/or
confidential and/or privileged information of GTSI, Former Employee further
agrees as follows:

           (a)  That, except with prior written authorization from GTSI's CEO or
COO, for purposes related to GTSI's best interests, he will not directly or
indirectly duplicate, remove, transfer, disclose or utilize, nor knowingly allow
any other person to duplicate, remove, transfer, disclose or utilize, any
property, assets, trade secrets or other things of value, including, but not
limited to, records, techniques, procedures, systems, methods, market research,
distribution arrangements, advertising and promotional materials, lists of past,
present or prospective customers, and data prepared for, stored in, processed by
or obtained from, an automated information system belonging to or in the
possession of GTSI which are not intended for and have not been the subject of
public disclosure. Former Employee agrees to safeguard all GTSI trade secrets in
his possession or known to him at all times so that they are not exposed to, or
taken by, unauthorized persons and to exercise his reasonable efforts to assure
their safekeeping. This subsection shall not apply to information that (i) is
now or later becomes generally known to the public or competitors of GTSI (other
than as a result of a breach of this Agreement); (ii) Former Employee lawfully
obtains from any third party who has lawfully obtained such information without
any obligation of confidentiality; or (iii) is later published or generally
disclosed to the public by GTSI. Former Employee shall bear the burden of
showing that any of the foregoing exclusions applies to any information or
materials.

           (b)  That all improvements, discoveries, systems, techniques, ideas,
processes, programs and other things of value made or conceived in whole or in
part by Former Employee with respect to any aspects of GTSI's current or
anticipated business while an employee of GTSI are and remain the sole and
exclusive property of GTSI, and Former Employee has disclosed all such things of
value to GTSI and will cooperate with GTSI to ensure that the ownership by GTSI
of such property is protected. All of such property of GTSI in Former Employee's
possession or control, including, but not limited to, all personal notes,
documents and reproductions thereof, relating to the business and the trade
secrets or confidential or privileged information of GTSI has already been, or
shall be immediately, delivered to GTSI.

       7.2 Former Employee further acknowledges that as the result of his prior
service as an officer and employee of GTSI, he has had access to, and is in
possession of, information and documents protected by the attorney-client
privilege and by attorney work product doctrine, such as information relating to
acquisitions and Board of Directors' correspondence. Former Employee understands
that the privilege to hold such information and documents confidential is
GTSI's, not his personally, and that he will not disclose the information or
documents to any person or entity without the express prior written consent of
the CEO or COO or Board of GTSI unless he is required to do so by law.

       7.3 Former Employee's obligations set forth in this Section 7 shall be in
addition to, and not instead of, Former Employee's obligations under any written
Nondisclosure Agreement.

       7.4 Former Employee acknowledges and agrees that the services rendered by
him to GTSI in the course of his prior employment were of a special and unique
character, and that breach by him of any provision of the covenants set forth in
this Section 7 will cause GTSI irreparable injury and damages.

                                       3
<PAGE>

Former Employee expressly agrees that GTSI shall be entitled, in addition to all
other remedies available to it whether at law or in equity, to injunctive and
other equitable relief to secure their enforcement.

       7.5 The parties expressly agree that the covenants contained in this
Section 7 are reasonable in scope, duration and otherwise; however, if any of
the restraints provided in these covenants are adjudicated to be excessively
broad as to area or time or otherwise, such restraint shall be reduced to
whatever extent is reasonable and the restraint shall be fully enforced in such
modified form. Any provisions of such covenants not so reduced shall remain in
full force and effect.

8.     PROHIBITION AGAINST DISPARAGEMENT

       GTSI and Former Employee each agree that during the Separation Period any
communication, whether oral or written, occurring on or off the premises of
GTSI, made by it/him or its/his agent to any person or entity (including,
without limitation, any GTSI employee, customer, vendor, supplier and any
competitor and any person associated with any media) which in any way relates to
his or to GTSI or to GTSI's directors, officers, management or employees: (1)
will be truthful; and (2) will not disparage or undermine the reputation or
business practices of Former Employee or GTSI or its directors, officers,
management or employees. The only exceptions to the foregoing shall be: (1)
truthful statements privately made to (a) the CEO or COO of GTSI, or their
designated representatives, (b) any member of GTSI's Board of Directors, (c)
GTSI's auditors, (d) inside or outside counsel of GTSI, (e) Former Employee's
counsel or (f) Former Employee's spouse; (2) truthful statements lawfully
compelled and made under oath; (3) truthful statements made to specified persons
upon and in compliance with prior written authorization from or in connection
with formal legal or administrative proceedings, GTSI's CEO or COO or Board; and
(4) truthful statements made by GTSI's CEO or COO to specified persons upon and
in compliance with prior authorization from Former Employee asking them to
respond to inquiries from such specified persons.

9.     COOPERATION

       Former Employee agrees that during the Separation Period he will
cooperate fully and reasonably with GTSI in connection with any future or
currently pending matter, proceeding, investigation, litigation or threatened
litigation: (1) directly or indirectly involving GTSI (which, for purposes of
this section, shall include GTSI and each of its current and future
subsidiaries, successors or permitted assigns); or (2) directly or indirectly
involving any director, officer or employee of GTSI (with regard to matters
relating to such person(s) acting in such capacities with regard to GTSI
business). Such cooperation shall include making himself available upon
reasonable notice at reasonable times and places to consult with and to testify
truthfully (at GTSI's expense for reasonable, pre-approved out-of-pocket travel
costs in any action as reasonably requested by the CEO or COO or the Board of
Directors. Former Employee further agrees to promptly notify GTSI's CEO or COO
in writing in the event that he receives any legal process or other
communication purporting to require or request him to produce testimony,
documents, information or things in any manner related to GTSI, its directors,
officers or employees, and that he will not produce testimony, documents,
information or other things with regard to any pending or threatened lawsuit or
proceeding regarding GTSI without giving GTSI prior written notice of the same
and reasonable time to protect its interests with respect thereto. Former
Employee further promises that during the Separation Period when so directed by
the CEO or COO or the Board of Directors, he will make himself available to
attend any such legal proceeding and will truthfully respond to any questions in
any manner concerning or relating to GTSI and will produce all documents and
things in his possession or under his control which in any manner concern or
relate to GTSI.

                                       4
<PAGE>

10.    SOLE ENTITLEMENT

       Former Employee acknowledges and agrees that his sole entitlement to
compensation, payments of any kind, monetary and non-monetary benefits and
perquisites with respect to his prior GTSI relationship (as an officer and
employee) is as set forth in this Agreement, stock option agreements, and COBRA.


11.    MUTUAL RELEASE OF CLAIMS

       11.1 Former Employee forever releases and discharges GTSI and the
predecessor corporation of GTSI as well as the successors, current or prior
stockholders of record, officers, directors, heirs, predecessors, assigns,
agents, employees, attorneys and representatives of each of them, past or
present, from any and all cause or causes of action, actions, judgments, liens,
indebtedness, damages, losses, claims, liabilities, expenses and demands of any
kind or character whatsoever, whether known or unknown, anticipated or not
anticipated, whether or not previously brought before any state or federal
agency, court or other governmental entity which are existing on or arising
prior to the date of this Agreement and which, directly or indirectly, in whole
or in part, relate or are attributable to, connected with, or incidental to the
previous employment of Former Employee by GTSI, the separation of that
employment, and any dealings between the parties concerning Former Employee's
employment existing prior to the date of execution of this Agreement, excepting
only claims arising from a breach by GTSI of this Agreement including those
obligations recited herein or to be performed hereunder, including but not
limited to any and all claims of discrimination on account of sex, race, age,
handicap, veteran status, national origin or religion, and claims or causes of
action based upon any equal employment opportunity laws, ordinances, regulations
or orders, including but not limited to Title VII of the Civil Rights Act of
1964 and the Age Discrimination In Employment Act, the Americans With
Disabilities Act, Executive Order 11246, the Rehabilitation Act and any
applicable state or local anti-discrimination statutes; claims for breach of any
contract, agreement or promises made prior to this date; claims for wrongful
termination actions of any type, breach of express or implied covenant of good
faith and fair dealing; intentional or negligent infliction of emotional
distress; claims for libel, slander or invasion of privacy; provided, however,
that Former Employee and GTSI agree that Former Employee does not waive any
rights or claims under the Age Discrimination In Employment Act that may arise
after the execution of this document by Former Employee. This proviso is
intended to exclude from release only claims "that arise after" execution of
this document by Former Employee as provided for by the Older Workers Benefit
Protection Act. This release also applies to any claims or rights that Former
Employee might have or assert with respect to any claims or rights, if any,
concerning any GTSI bonus plan applicable to GTSI officers. Nothing contained in
this Section 11.1 shall affect any rights, claims or causes of action which
Former Employee may have (1) as a stockholder of GTSI; (2) to indemnification by
GTSI, to the extent required under the provisions of GTSI's Certificate of
Incorporation, GTSI's By-Laws, the Delaware General Corporation Law, insurance
or contracts, with respect to matters relating to Former Employee's prior
service as an officer, employee and agent of GTSI; (3) to make claims against or
seek contribution from anyone not released by the first sentence of this Section
11.1with respect to any matter or anyone released by the first sentence of this
Section 11.1 with respect to any matter not released thereby; or (4) with
respect to GTSI's performance of this Agreement.

       11.2 GTSI forever releases and discharges Former Employee, and his heirs,
from any and all cause or causes of action, actions, judgments, liens,
indebtedness, damages, losses, claims, liabilities, expenses and demands of any
kind or character whatsoever, whether known or unknown, anticipated or not
anticipated, whether or not previously brought before any state or federal
agency, court or other governmental entity which are existing on or arising
prior to the date of this Agreement and which, directly or indirectly, in whole
or in part, relate or are attributable to, connected with, or incidental to the

                                       5
<PAGE>

previous employment of Former Employee by GTSI, the separation of that
employment, and any dealings between the parties concerning Former Employee's
employment existing prior to the date of execution of this Agreement, excepting
only claims arising from a breach by Former Employee of this Agreement including
those obligations recited herein or to be performed hereunder. Nothing contained
in this Section 11.2 shall affect any rights, claims or causes of action which
GTSI may have to make claims against or seek contribution from anyone not
released by the first sentence of this Section 11.2 with respect to any matter
or anyone released by the first sentence of this Section 11.2 with respect to
any matter not released thereby; or with respect to Former Employee's
performance of this Agreement.

12.    ASSIGNMENT

       Former Employee represents and warrants that he has not assigned,
transferred or granted or purported to assign, transfer or grant any claims,
entitlement, matters, demands or causes of action herein released, disclaimed,
discharged or terminated, and agrees to indemnify and hold harmless GTSI from
and against any and all costs, expense, loss or liability incurred by GTSI as a
consequence of any such assignment, transfer or grant.

13.    FORMER EMPLOYEE REPRESENTATIONS

       Notwithstanding that this Agreement may be entered into subsequent to the
Termination Date, except as listed by Former Employee on Exhibit B, from the
period beginning on the Termination Date to this Agreement's Effective Date,
Former Employee represents and warrants that he has not acted or omitted to act
in any respect which involves fraud or malfeasance towards GTSI or which
directly or indirectly would have constituted a violation of Sections 7, 8 or 9
herein had this Agreement then been in effect.

14.    MISCELLANEOUS

       14.1 NOTICES. All notices and demands referred to or required herein or
pursuant hereto shall be in writing, shall specifically reference this Agreement
and shall be deemed to be duly sent and given upon actual delivery to and
receipt by the relevant party (which notice, in the case of GTSI, must be from
an officer of GTSI) or five days after deposit in the U.S. mail by certified or
registered mail, return receipt requested, with postage prepaid, addressed as
follows (if, however, a party has given the other party due notice of another
address for the sending of notices, then future notices shall be sent to such
new address):

            (a)      If to GTSI:                GTSI Corp.
                                                3901 Stonecroft Boulevard
                                                Chantilly, Virginia  20151"0808
                                                Attn:  Chief Operating Officer

            (b)      If to Former Employee:     Joel A. Lipkin
                                                1638 Montmorency Drive
                                                Vienna, VA    22182

       14.2 LEGAL ADVICE AND CONSTRUCTION OF AGREEMENT. Both GTSI and Former
Employee have received (or have voluntarily and knowingly elected not to
receive) independent legal advice with respect to the advisability of entering
into this Agreement and neither has been entitled to rely upon or has in fact
relied upon the legal or other advice of the other party or such other party's
counsel (or employees) in entering into this Agreement. In Former Employee's
case, he is/was expressly advised by GTSI of his right to consult an attorney to
review this Agreement. Each party has participated in the drafting and

                                       6
<PAGE>

preparation of this Agreement, and, accordingly, in any construction or
interpretation of this Agreement, the same shall not be construed against any
party by reason of the source of drafting.

       14.3 PARTIES' UNDERSTANDING. GTSI and Former Employee state that each has
carefully read this Agreement, that it has been fully explained to it/him by
its/his attorney (or that it/he has voluntarily and knowingly elected not to
receive such explanation), that it/he fully understands its final and binding
effect, that the only promises made to it/him to sign the Agreement are those
stated above, and that it/he is signing this Agreement voluntarily.

       14.4 RECITALS AND SECTION HEADINGS. Each term of this Agreement is
contractual and not merely a recital. All recitals are incorporated by reference
into this Agreement. Captions and section headings are used herein for
convenience only, are no part of this Agreement and shall not be used in
interpreting or construing it.

       14.5 ENTIRE AGREEMENT. This Agreement constitutes a single integrated
contract expressing the entire agreement of the parties with respect to the
subject matter hereof and supersedes all prior and contemporaneous oral and
written agreements and discussions with respect to the subject matter hereof.
Notwithstanding the foregoing, the parties understand and agree that any
Nondisclosure Agreement and all other written agreements between Former Employee
and GTSI are separate from this Agreement and, subject to the terms and
conditions of each such agreement, shall survive the execution of this
Agreement, and nothing contained in this Agreement shall be construed as
affecting the rights or obligations of either party set forth in such
agreements.

       14.6 SEVERABILITY. In the event any provision of this Agreement or the
application thereof to any circumstance shall be held by a court of competent
jurisdiction to be invalid, illegal or unenforceable, or to be excessively broad
as to time, duration, geographical scope, activity, subject or otherwise, it
shall be construed to be limited or reduced so as to be enforceable to the
maximum extent allowed by applicable law as it shall then be in force, and if
such construction shall not be feasible, then such provision shall be deemed to
be deleted herefrom in any action before that court, and all other provisions of
this Agreement shall remain in full force and effect.

       14.7 AMENDMENT AND WAIVER. This Agreement and each provision hereof may
be amended, modified, supplemented or waived only by a written document
specifically identifying this Agreement and signed by each party hereto. Except
as expressly provided in this Agreement, no course of dealing between the
parties hereto and no delay in exercising any right, power or remedy conferred
hereby or now or hereafter existing at law, in equity, by statute or otherwise,
shall operate as a waiver of, or otherwise prejudice, any such rights, power or
remedy.

       14.8 CUMULATIVE REMEDIES. None of the rights, powers or remedies
conferred herein shall be mutually exclusive, and each such right, power or
remedy shall be cumulative and in addition to every other right, power or
remedy, whether conferred herein or now or hereafter available at law, in
equity, by statute or otherwise.

       14.9 SPECIFIC PERFORMANCE. Each party hereto may obtain specific
performance to enforce its/his rights hereunder and each party acknowledges that
failure to fulfill its/his obligations to the other party hereto would result in
irreparable harm.

       14.10 VIRGINIA LAW AND LOCATION. This Agreement was negotiated, executed
and delivered within the Commonwealth of Virginia, and the rights and
obligations of the parties hereto shall be construed and enforced in accordance
with and governed by the internal laws (and not the conflict of

                                       7
<PAGE>

laws) of the Commonwealth of Virginia applicable to the construction and
enforcement of contracts between parties resident in Virginia which are entered
into and fully performed in Virginia.

       14.11 FORCE MAJEURE. Neither GTSI nor Former Employee shall be deemed in
default if its/his performance of obligations hereunder is delayed or become
impossible or impracticable by reason of any act of God, war, fire, earthquake,
strike, civil commotion, epidemic, or any other cause beyond such party's
reasonable control.

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

       14.13 SUCCESSORS AND ASSIGNS. Neither party may assign this Agreement or
any of its rights or obligations hereunder (including, without limitation,
rights and duties of performance) to any third party or entity, and this
Agreement may not be involuntarily assigned or assigned by operation of law,
without the prior written consent of the non-assigning party, which consent may
be given or withheld by such non-assigning party in the sole exercise of its
discretion, except that GTSI may assign this Agreement to a corporation
acquiring: (1) 50% or more of GTSI's capital stock in a merger or acquisition;
or (2) all or substantially all of the assets of GTSI in a single transaction;
and except that Former Employee may transfer or assign his rights under this
Agreement voluntarily, involuntarily or by operation of law upon or as a result
of his death to his heirs, estate and/or personal representative(s). Any
prohibited assignment shall be null and void, and any attempted assignment of
this Agreement in violation of this section shall constitute a material breach
of this Agreement and cause for its termination by and at the election of the
other party hereto by notice. This Agreement shall be binding upon and inure to
the benefit of each of the parties hereto and, except as otherwise provided
herein, their respective legal successors and permitted assigns.

       14.14 PAYMENT PROCEDURE. All payments by GTSI to Former Employee or by
Former Employee to GTSI may be by, at the paying party's election, cash, wire
transfer or check. Neither party may reduce any payment or obligation due by any
amount owed or believed owed to the other party under any other agreement,
whether oral or written, now in effect or later entered into.

       14.15 SURVIVAL. The definitions, representations and warranties herein as
well as obligations set forth in Sections 7, 10, 11,12 and 14 shall survive any
termination of this Agreement for any reason whatsoever.

       14.16 NO ADMISSION. Neither the entry into this Agreement nor the giving
of consideration hereunder shall constitute an admission of any wrongdoing by
GTSI or Former Employee.

       14.17 LIMITATION OF DAMAGES. Except as expressly set forth herein, in any
action or proceeding arising out of, relating to or concerning this Agreement,
including any claim of breach of contract, liability shall be limited to
compensatory damages proximately caused by the breach and neither party shall,
under any circumstances, be liable to the other party for consequential,
incidental, indirect or special damages, including but not limited to lost
profits or income, even if such party has been apprised of the likelihood of
such damages occurring.

       14.18 EFFECTIVE DATE. Former Employee expressly acknowledges that he has
been advised that he has 14 days to review this Agreement before making a
decision to execute it. This Agreement shall become effective upon execution of
this Agreement by Former Employee (the "Effective Date").

                                       8
<PAGE>


GTSI CORP.                                   JOEL A. LIPKIN


By:   /s/ John T. Spotila                    Signature: /s/ Joel Lipkin
   -------------------------------------                ------------------------
                                                            Joel A. Lipkin

Print Name:   John T. Spotila
           -----------------------------

Print Title: Executive V.P. & C.O.O.
            ----------------------------

Date:   October 8, 2001                      Date:   October 8, 2001
     -----------------------------------          ------------------------------


<PAGE>

<TABLE>
<CAPTION>

                                                     EXHIBIT A

PURCHASE OF STOCK BY GTSI

<S>               <C>            <C>               <C>               <C>              <C>

----------------- -------------- ----------------- ----------------- ---------------- ------------------------
                                                          GTSI
    Options            Date          Exercise           Purchase           Cost            Payment Amount
     Vested           Issued           Cost               Price        Differential
----------------- -------------- ----------------- ----------------- ---------------- ------------------------
     45,000         3/25/1997         $5.25             $6.25             $1.00             $45,000.00
----------------- -------------- ----------------- ----------------- ---------------- ------------------------
      9,000         3/25/1999         $3.75             $6.25             $2.50             $22,500.00
----------------- -------------- ----------------- ----------------- ---------------- ------------------------
     30,000         8/3/1999          $4.00             $6.25             $2.25             $67,500.00
----------------- -------------- ----------------- ----------------- ---------------- ------------------------
      6,667         11/2/1999         $2.88             $6.25             $3.37             $22,467.79
----------------- -------------- ----------------- ----------------- ---------------- ------------------------
      1,500         7/10/200          $3.31             $6.25             $2.94              $4,410.00
----------------- -------------- ----------------- ----------------- ---------------- ------------------------
TOTAL                                                                                 TOTAL
     92,167                                                                                 $161,877.79
----------------- -------------- ----------------- ----------------- ---------------- ------------------------

<CAPTION>
<S>               <C>            <C>               <C>               <C>              <C>
----------------- -------------- ----------------- ----------------- ---------------- ------------------------
    Options            Date           Exercise           GTSI              Cost            Payment Amount
    Vesting           Issued            Cost           Purchase        Differential
      Upon                                               Price
   Execution
----------------- -------------- ----------------- ----------------- ---------------- ------------------------
     6,667          11/2/1999         $2.88             $6.25             $3.37             $22,469.79
----------------- -------------- ----------------- ----------------- ---------------- ------------------------
     1,500          7/10/2000         $3.31             $6.25             $2.94              $4,410.00
----------------- -------------- ----------------- ----------------- ---------------- ------------------------
TOTAL                                                                                 TOTAL
     8,167                                                                                  $26,879.79
----------------- -------------- ----------------- ----------------- ---------------- ------------------------
</TABLE>

    ----------------- -----------------------
         Total
        Options            Total Payment
       Purchased              Amount
        by GTSI
    ----------------- -----------------------
         100,334            $188,757.58
    ----------------- -----------------------


                                       10
<PAGE>

                                    EXHIBIT B

                           EXCEPTIONS (PURSUANT TO 13)
                           ---------------------------

                                      None








                                       11