AGREEMENT AND PLAN OF MERGER
                                 AMENDMENT NO. 1


         This  Amendment No. 1 (this  "Amendment")  to the Agreement and Plan of
Merger,  dated  as of  March  30,  1999,  is  entered  into by and  among  Tyler
Corporation,  a Delaware corporation  ("Parent"),  CPS Systems, Inc., a Delaware
corporation  and  wholly-owned  subsidiary  of Parent  ("Merger  Sub"),  and CPS
Systems, Inc., a Texas corporation (the "Company").

         WHEREAS,  Parent, Merger Sub, and the Company entered into that certain
Agreement  and  Plan  of  Merger  dated  as  of  March  30,  1999  (the  "Merger
Agreement");

         WHEREAS,  each of Parent,  Merger Sub, and the Company  desire to amend
the Merger Agreement as set forth in this Amendment;

         THEREFORE,  in  consideration  of  the  foregoing  and  the  respective
covenants  and   agreements  set  forth  herein  and  other  good  and  valuable
consideration,  the  receipt  and  sufficiency  of which  all  parties  mutually
acknowledge, the parties agree as follows:

         1. Section 7.01 of the Merger Agreement, Termination, is hereby amended
by deleting the terms and  provisions of Section  7.01(b) in their  entirety and
replacing such terms and provisions with the following:

         "(b) by  Parent,  if at any  time  prior  to the  sixtieth  (60th)  day
         immediately  following  execution of this  Agreement the results of its
         due diligence  review of the Company are not  satisfactory to Parent in
         its sole discretion;"

         2. Section 5.11 of the Merger Agreement,  Registration Statement; Proxy
Statement,  is hereby amended by deleting the first sentence of Section  5.11(a)
in its entirety and replacing such sentence with the following:

         "(a) Promptly  after the expiration of sixty (60) days from the date of
         this  Agreement,  Parent  and the  Company  will use  their  respective
         commercially  reasonable  efforts  to prepare  and file a  registration
         statement  on Form S-4 with the SEC,  containing  a proxy  statement  /
         prospectus for the stockholders of the Company,  in connection with the
         registration of the offer and sale of the Tyler Shares."

         3. All other terms and provisions of the Merger  Agreement shall remain
unchanged.

         4. This Amendment will be governed by and construed in accordance  with
the  substantive  laws of the  State of  Texas,  without  giving  effect  to any
conflicts-of-law,  rule, or principle that might require the  application of the
laws of another jurisdiction.

         IN WITNESS WHEREOF, each of the parties has caused this Amendment to be
executed by a duly authorized officer to be effective as of April 20, 1999.

                                         TYLER CORPORATION,
                                         a Delaware corporation



                                         By:      _______________________
                                         Name:    John M. Yeaman
                                         Title:   President



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IN WITNESS WHEREOF, each of the parties has caused this Amendment to be executed
by a duly authorized officer to be effective as of April 20, 1999.


                                   CPS SYSTEMS, INC.,
                                   a Delaware corporation and wholly-owned
                                   subsidiary of Tyler Corporation



                                   By:      ________________________________
                                   Name:    John M. Yeaman
                                   Title:   President


                                   CPS SYSTEMS, INC.,
                                   a Texas corporation



                                   By:      ________________________________
                                   Name:    ________________________________
                                   Title:   ________________________________