PROSPEC
                                                                   Computer Systems





                       This is the third README file for Expert86

      The PROSPEC range of shareware is growing all the time, as new products are 
      introduced and existing products are released on new machines.  As we prepare 
      this file we are currently transferring the following products to the Amstrad 
      PCW.  By the time you read this they may well be available, so copy them from 
      other people if you can or contact us for an up to date copy.  Our address 
      appears at the end of this document.  Each program is available free of 
      charge with on-disk documentation.  Full documentation is supplied to all 
      registered users.

      We are also compiling a library of shareware written by other people or 
      organisations (often referred to in the press as 'public domain' software).  
      Machines currently supported are the Amstrad CPC 6128, the PCW range, and 
      IBM/compatibles (including the Amstrad PC 1512).  The emphasis is firmly on 
      very low-cost software, in keeping with the spirit of shareware.  In contrast 
      to some suppliers we offer software at the lowest price we can, and we quite 
      definitely do not require you to pay a membership fee before allowing you to 
      access our library.  Software on 3" disk for CP/M machines is available at  
      £3.50 and PC software on 5.25" disk costs £3.00.  Prices include VAT.  Send 
      for our free catalogue.





      P.T.G.                     *** Available soon ***

      P.T.G. is a Parse Table Generator, in simple terms a program that helps you 
      to write compilers and interpreters.  It can cope with most of the languages 
      commonly found on micros - BASIC, C, Fortran, Pascal, Algol, Modula-2, Ada, 
      or any languages similar to these.

      Parse table generators have been available for many years on expensive mini-
      computers.  A well-known example is called YACC.  However, we know of no such 
      program for micros.

      Compilers used to be notoriously difficult to write.  However, modern ideas, 
      such as parse tables and recursive descent, make the process of compiler-
      writing very much simpler.  It is now certainly feasible for the interested 
      ameteur to write his or her own compiler at home.  All that is needed is a 
      little effort.

      Parse tables lie at the heart of many commercial compilers - once a parse 
      table is available for a language everything else begins to fall into place.  
      It is possible to write a parse table by hand.  All that's needed is a large 
      sheet of paper, a soft pencil, a good eraser, and a very great deal of 
      patience.  It is a BIG job.  The odds against getting it finished without 
      making a mistake somewhere along the line are massive.

      A parse table generator like P.T.G. does the job for you.  It will construct 
      a complete parse table based on your instructions for any conventional 
      language (such as those listed above) you wish to implement.

      We wrote P.T.G. because we wanted to develop compilers of our own.  It has 
      been used by ourselves to generate full scale C and Fortran compilers.  If 
      you would like to try it out send £3.50 + 50p postage for the P.T.G. 
      shareware disk.
      Registered P.T.G. users recieve:


       - a detailed manual explaining how to use P.T.G. to generate parse tables
         and how to use those tables to write a completely functional compiler for 
         an existing computer language (or one of your own devising)

       - a definition of a full implementation of the language C (as specified by
         Kernighan and Ritchie) ready to feed into P.T.G.  This will allow you to 
         produce a working parse table for C immediately

       - definitions of tiny-BASIC and tiny-Fortran (simple versions of BASIC and
         Fortran featuring all the common commands) ready to feed to P.T.G.

       - entitlement to upgrades if any bugs are ever reported

       - entitlement to upgrades if P.T.G. is improved in the future

       - free entry to our P.T.G. competition








                PROSPEC Computer Systems
                Shareware
                PO BOX 28
                Beeston
                Nottingham
                NG9 1PH
                Great Britain





      When it left us this disk contained:

       HELP.COM      - advice on getting started
       README.1      - introduction to Expert86
       README.2      - details of our Expert86 competition
      [README.3]     - this file
       README.4      - how to copy Expert86
       README.5      - more information on Expert86
       README.6      - how to use Expert86
       README.7      - a blank order form, ready to print out
       README.8      - details of the ED.COM editor
       E86.COM       - the Expert86 expert system generator
       CAR           - a sample expert system for Expert86 - training set
       CAR.ATT       - a sample expert system for Expert86 - definitions
       LIST.COM      - a utility, similar to TYPE.COM