AMENDMENT NO. 1 TO
                            ASSET PURCHASE AGREEMENT

          This Amendment to Asset Purchase Agreement (the "Amendment"), dated as
of April 6,  2000,  is  entered  into by and  among  Amherst  Computer  Products
Southwest,  LP,  a Texas  limited  partnership  ("Amherst  Southwest"),  Amherst
Technologies, L.L.C., a Nevada limited liability company ("AmTech"), and Allstar
Systems, Inc., a Delaware corporation ("Allstar").

                                   BACKGROUND:

     A.   Amherst  Southwest,  AmTech and Allstar have  heretofore  entered into
that certain Asset  Purchase  Agreement,  dated as of March 16, 2000 (the "Asset
Purchase  Agreement").  All  capitalized  terms used and not  otherwise  defined
herein shall have the meanings ascribed to them in the Asset Purchase Agreement.

     B.   The parties  desire to make certain  amendments to the Asset  Purchase
Agreement.

     NOW,  THEREFORE,  in  consideration of the premises and the mutual promises
herein made, Amherst Southwest, AmTech and Allstar agree as follows.


                                   AGREEMENTS
     1.   Status of the Asset Purchase  Agreement.  Except as  specifically  set
forth herein, the Asset Purchase Agreement shall remain in full force and effect
and shall not be waived,  modified,  superseded  or  otherwise  affected by this
Amendment.  This  Amendment  is not to be  construed  as a  release,  waiver  or
modification of the terms, conditions,  representations,  warranties, covenants,
rights  or  remedies  set  forth in the  Asset  Purchase  Agreement,  except  as
specifically set forth herein.

     2.   Amendments to the Asset Purchase Agreement.

          (i)  The  following  provision  shall be added as Section  2.14 of the
               agreement:

                  "2.14    Pre-Closing Escrow; Expense Reimbursement.

                           (a) On or before  April 10, 2000,  Amherst  Southwest
                  shall wire transfer  $500,000 into an escrow  account with the
                  Escrow  Agent to be  established  by the  parties,  such funds
                  (together  with  interest  or  income  earned  thereon)  to be
                  applied  against the  Purchase  Price upon  Closing;  provided
                  however,  if the Closing of the  transactions  contemplated by
                  the Asset Purchase  Agreement does not occur by June 30, 2000,
                  then the  parties  shall  cause  the  $500,000  escrow  amount
                  (together  with interest or income earned  thereon) to be paid
                  on or before July 5, 2000, as follows:

                                            (1) If the  Closing  does not  occur
                           solely  because  of  the  breach  by  Allstar  of its
                           representations  or  obligations  in, or a failure of
                           the conditions  under, the following  sections of the
                           Agreement, the funds in





                           escrow shall be paid to Amherst  Southwest:  Sections
                           4.1,  4.2, 4.4, 4.8,  6.3,  7.1(f),  7.1(k),  7.1(l),
                           7.1(m), and 9.1(a).

                                            (2) If the  Closing  does not  occur
                           solely  because of the  failure of the  condition  of
                           Section 7.1(d) of the Agreement,  the funds in escrow
                           shall be split  evenly  between  and paid to  Amherst
                           Southwest and Allstar.

                                            (3) If the  Closing  does not  occur
                           for  any  reason  other  than  one  which   expressly
                           entitles  Amherst  Southwest  to  receive  all  or  a
                           portion of the escrow  funds under  paragraphs 1 or 2
                           above, the escrow funds shall be paid to Allstar. The
                           form of Escrow  Agreement  shall be in  substantially
                           the  form of  Exhibit  A and  attached  to the  Asset
                           Purchase Agreement as Exhibit G.


                           (b) On or before  April 10, 2000,  Amherst  Southwest
                  agrees to pay to Allstar by wire  transfer the sum of $250,000
                  in addition to the Purchase Price as a non-accountable expense
                  reimbursement."

                           (ii) Section 9.2 of the  Agreement is hereby  deleted
                  in its entirety and replaced with the following:

                                    "9.2 Termination Fee. In the event that this
                           Agreement is terminated by Amherst Southwest pursuant
                           to  Section  9.1(b)(3)  or  by  Allstar  pursuant  to
                           Section  9.1(c)(3),  Allstar  shall within 2 Business
                           Days after such  termination  pay or cause to be paid
                           to  Amherst  Southwest,   as  compensation  for  lost
                           opportunities   and  reimbursement  of  out-of-pocket
                           expenses:   (i)   Five   Hundred   Thousand   Dollars
                           ($500,000),  (ii)  the  amount  of the  escrow  funds
                           (together  with  interest or income  earned  thereon)
                           under that certain Escrow Agreement dated as of April
                           6, 2000  among  Allstar,  Amherst  Southwest  and the
                           Escrow Agent thereunder, (iii) the amount of $250,000
                           previously  paid  by  Amherst  Southwest  to  Allstar
                           pursuant  to Section  2.14(b),  as a  non-accountable
                           expense  reimbursement,  and Allstar shall assume and
                           Amherst  Southwest shall assign to Allstar all rights
                           and  obligations of Amherst  Southwest  under (1) the
                           Lease between Amherst Southwest and Weingarten Realty
                           Advisors  for the  premises  located  at 11727 W. Sam
                           Houston Parkway South, Suite D, Houston, Texas 77031,
                           and  (2)  Section  3  of  the  Voting  Agreement,  as
                           amended. AmTech and Amherst Southwest agree that upon
                           such payments to Amherst Southwest and the assumption
                           of such obligations by Allstar, Allstar shall have no
                           further  liability  to either of them  arising  under
                           this Agreement."

     3.   Effectiveness of this Amendment.  The  effectiveness of this Amendment
is  contingent  upon the  execution of Amendment No. 1 to the Voting and Support
Agreement dated as of April 6, 2000 by and among Amherst  Southwest and James H.
Long (the "Voting Agreement Amendment").

     4.   Representations and Warranties of Entities. Each of Amherst Southwest,
AmTech and Allstar  represents  and warrants  that its  execution,  delivery and
performance  of  this  Amendment  has  been  duly  authorized  by all  necessary
corporate and partnership  action and that this Amendment is a legal,  valid and
binding obligation of the parties in accordance with its terms.  Allstar further
represents  and warrants that its board of directors has approved the Voting and
Support  Agreement  dated as of March 16, 2000 between  Amherst  Southwest,  and
James H. Long, and the Voting  Agreement  Amendment,  in a manner  sufficient to
make  the  restrictions  contained  in  Section  203  of  the  Delaware  General
Corporation  Law  inapplicable  to the  transactions  contemplated  by the Asset
Purchase Agreement, as amended.

     5.   Counterparts.  This  Amendment  may  be  executed  in  any  number  of
counterparts,  each of  which  shall  be  deemed  an  original  and all of which
together shall constitute one and the same instrument.

     6.   Governing Law. This Amendment  shall be governed by and construed in
accordance with the domestic laws of the State of Delaware without giving effect
to any choice or  conflict  of law  provision  or rule  (whether of the State of
Delaware or any other jurisdiction) that would cause the application of the laws
of any jurisdiction other than the State of Delaware.

     IN WITNESS WHEREOF,  the undersigned have executed this Amendment as of the
date first above written.

                                     AMHERST COMPUTER PRODUCTS SOUTHWEST, LP

                                     By:      /s/ Gerald Birin

                                     Title:            CFO


                                     ALLSTAR SYSTEMS, INC.

                                     By:      /s/ James H. Long

                                     Title: James H. Long,
                                            Chief Executive Officer


                                     AMHERST TECHNOLOGIES, L.L.C.

                                     By:      /s/ Gerald Birin

                                     Title:            CFO