HPAVC/HPAVC CD-ROM.iso/PCGAMN6.ZIP/BACKGMMN.DOC

Text File | 1986-09-08 | 13KB | 298 lines

/*
**  backgmmn.doc - history file

   Program  : PC-Gammon IV with User-Defined ** COLOR **
   Computer : 100% IBM PC compatibles
   Language : Microsoft C 4.00
            :
   Author   : David C. Oshel
            : 1219 Harding Avenue
            : Ames, Iowa 50010
            : August 10, 1986


HISTORY
-------
v6.0 9/08/86 - Now linking to CIAO.LIB, with fast video RAM output

v5.3 9/01/86 - Minor change, just added typeafile for the user's manual.
               Typeafile is a new addition to the IO.LIB.

v5.2 8/21/86 - Got rid of clairol.obj, in favor of an improved io.lib.
               Includes ambiguity test in clairol(), adds a mode
               argument to the vid_init() routine, adds a vid_exit()
               routine.  The library is smaller, and allows a smaller
               obj file where only sound or keyin is needed.  The clairol()
               function now does a wputs("^0"); on exit to ensure the new
               normal mode is set.

               PC-Gammon now allows a command line parameter.
               Sets video mode 2 instead of video mode 3, if present.
               Usage: backgmmn b&w

               Actually, any argument will do, but document "b&w" for users.



v5.1 8/18/86 - minor add: "^0" to mycount(), yrcount() format strings
               minor edits in backgmmn.h to remove obsolete function decls

               Note that wprintf("^%d", cnt); is DANGEROUS, depending on
               how the cnt argument gets formatted.  The correct usage in
               this case is wprintf("^0%d", cnt);, with the zero!  This
               ensure that the ^ escape finds a legitimate command char in
               the anticipated position.

               Note that the current main() and command() fns in bg0.c were
               split apart in version 5.0:  vid_init() was in the wrong
               place to correctly save the startup screen for cga!  The
               public domain version is ok, has the change.  Note also that
               setting video mode 3 absolutely will clear the cga startup
               screen and send cursor home, so there's no point saving it,
               but we do it anyway.  It's a good screen to come home to.

               TO DO: ruminate on improvements in playing strategy.  Torve
               seems unexpectedly strong, lately.  Have I overlooked some
               strength not noted there before?  Need to pin that last bug
               in the Arrange command, if I can figure out what it is!  Is
               Torve reacting to full moon?  Are small but noticeable changes
               in strategy the result of using a $600 compiler for a change?
               Have I finally gone mad?


Version 5.0  August 17, 1986, the LAST public domain version of PC-Gammon!

   a) Reorganized the code into four sensible modules, with a
      common header file, for use with MAKE.  The source files are
      backgmmn.h, bg0.c, bg1.c, bg2.c, bg3.c.  Supporting modules
      are clairol.obj, and its .h file.

   b) Revised code to use the new wprintf() function. (<stdarg.h> in
      Microsoft C 4.0 is magic!)

      Simplified the savescreen(), restorescreen() calls to do automatic
      heap allocation/free.

   c) Added the CLAIROL module to change screen attributes.
      (Combined module from CURSES.C, SOUND.C., plus clairol() routine.)

   d) In other words, PC-Gammon now has full color support for the cga
      and color monitor.  WITHOUT sacrificing special support for the
      monochrome adapter.



Version 4.4  August 12, 1986

   a) Revised BGTOKENS.C to default to my preferred stones.
   b) Added H(ues stub to main command line, if not monochrome.

Version 4.3  August 10, 1986

   a) Minor changes to CURSES.OBJ file.  Variables for screen
      attributes can support color selection in a H(ues command.
      Appended the old GETMS file to CURSES.  Some changes in
      argument order for windowing commands (in the direction
      of easier to remember and more consistent).

Version 4.2  August 3, 1986

   a) V.4.1 FAILED its test on the cga card!  Modified CURSES.OBJ to
      correctly set 80x25 text 16/8 mode on PCs with cga cards.  Moved
      call to title() into setup(), so the change is noted before
      anything is output to screen.  Tested results on NCR PC Model 3
      with cga, and on Epson Equity I.  Passed with flying colors (for
      B&W, that is)!

Version 4.1  August 2, 1986

   a) Minor revision to CURSES.OBJ allows wink() to handle '\b'.
      Discovered that Microsoft C 3.00 interprets '\008' as '\0',
      not '\b', so changed the backgammon source code accordingly.

Version 4.0  August 2, 1986 (PC clone version Gammon IV.40)

   a) Added sound and ultra-fast screen io.  Makes it a game for 100%
      clones only, now.  Totally ignores ANSI.SYS, if present.

   b) Altered keyin() and getms() to accept function parameters for
      the wait-for-input and the do-on-ESC routines.  For separate
      compilation later (maybe).

   c) Revised references to '\n' in user input routines because
      keyin() does not return newline when it encounters ENTER.
      In effect, the "All ok?" question now accepts ENTER and does
      not force users to type 'Y'.

   d) Fixed a bug in user's dice routine.

   e) Known BUG:  Computer does not come in from the bar on the first
      roll after Arrange-ing the board.



Version 3.1:  July 29, 1986 (MS-DOS version Gammon IV.31)

   a) Changed the keyin() routine to correctly handle Fn key inputs.
      Extended ASCII is returned with high bit set from now on.



Version 3:   July 27, 1986 (Original MS-DOS version Gammon IV.30)

   a) Numerous minor changes to the code reflect differences in
      C compilers and their standard libraries.   In particular,
      Microsoft C implements some functions as macros -- locating all
      the side effects of this approach can be troublesome when
      porting.

      Otherwise, this is just a "quick and dirty" port; old code which
      implemented for the Lear-Siegler ADM-3A terminal's lack of a
      clear-to-end-of-line command has not been optimized (or cleaned
      up, depending on your point of view).

   b) The graphics toggle (CP/M Kaypro) is a hilite toggle (MS-DOS ANSI).

   c) User bailout is ESC.  Control-C is trapped by MS-DOS and halts
      the program.

   d) The "kill typeahead" feature (in BG0.C) is commented out to improve
      play under the abominably slow conditions of IBM-clone i/o.



Version 2:   March 28, 1986 (CP/M)

   a) Fixed the bug in which the doubling cube might revert to its
      default value if the computer took back a move, and if the cube
      had been doubled one or more times during the opening roll-off
      but not yet offered.

   b) Fixed an odd bug in the Arrange command which occasionally caused
      stones to switch allegiance to the opponent's color, or else to
      mysteriously multiply to more than 15 on a side.

   c) An improved error handler now hints that BAR and HOME are words
      used in the game; also, slows down the incorrect entry routine so
      that it is less mysterious than before.

   d) Added a Graphic toggle to main command line.  Same as Control-K,
      as in previous versions; turns on/off the Kaypro '84 video graphics;
      uses the alternate token set defined in the CRT module below.

   e) Changed the break character back to Control-C; there is a
      proximity problem in keyboarding the escape key on a Kaypro
      keyboard.  (Various CP/M versions may have used either ESC or
      Control-C, depending.)

   f) There is no longer a sanction against cheating; if you bail
      out during play and re-Arrange the stones, your opponent
      does not change.

   g) As before, the computer will not always take (or find) a forced
      move.  The rule is that the player must take both dice if possible,
      or the larger if both are possible singly but not together.
      The playing algorithm attempts to find the legally required move,
      but will sometimes fail.  It is sometimes advantageous to avoid a
      forced move but the computer cannot make that distinction in this
      version; the program allows the same lenience for the human player.

      The cube is doubled when doubles are thrown during the opening
      rolloff to decide who goes first.  However, if the cube reaches 8,
      further pairs on the dice during rolloff have no effect.

      Gammon IV knows all the other OFFICIAL rules of the game;
      U.S. Navy and/or Saloon rules don't count.

   h) Improved coding in some routines, especially putstone(), which was
      far more baroque than necessary.  There is also some occasional
      re-coding, where I could not prevent myself.  The game strategy
      has not been changed, mostly because I don't fully understand it
      anymore, even though the documentation there is better than usual.
      It was written months ago in a white heat of inspiration; but I
      feel reluctant to submit myself to that strain again, without the
      prospect of remuneration.


INTRODUCTION
------------

Gammon IV is a full-screen backgammon game.  I wrote it for CP/M
some time ago, and have finally gotten around to porting it to MS-DOS.

Gammon IV has always been designed to run nicely on the lowest common
denominator of available computer terminals.  The CP/M version has a
number of sophisticated i/o features which are nevertheless compatible
with the Lear-Siegler ADM-3A (extremely) dumb terminal.

This version assumes 100% IBM-compatible io, for screen and sound.
Screen control is via ROM BIOS calls, sound control uses port io.




DISCUSSION ABOUT THE PORT FROM CP/M TO MS-DOS (Gammon IV.30)
------------------------------------------------------------
This is a straightforward "port" from CP/M to MS-DOS.  GAMMON IV was
originally written for the Kaypro 10.  It has now been translated for
the Epson Equity I, or any IBM-PC clone with an ANSI terminal (below).

The original language was Toolworks C/80, version 3.1 (CP/M), the
current language is Microsoft C, version 3.00 (MS-DOS).

Program modules have been altered to account for the PC-clone
environment.

In addition, certain in-line assembly kludges which were required in
the CP/M version have now been replaced by pure C code in the MS-DOS
version; i.e., there are some minor changes involving setjmp() and
longjmp(), which now control program logic in a more portable fashion.




DISCUSSION OF THE PROGRAM
_________________________

Gammon IV is probably the best FREE backgammon game ever written....
I'm not modest!  I wrote it because I was disgusted with the price
and dullness of all other public domain programs which allegedly play
backgammon.

This program has THREE DIFFERENT PLAYING STYLES, any one of which can
consistently beat a novice player, and occasionally beat a good player.
In all three levels, the computer's strategy can even seem brilliant;
there is nothing routine about it.

This version incorporates a few minor changes and bug fixes which make it
different from previous editions which have appeared on various bulletin
boards and club offerings around the country.  This is a public domain
program.  Feel free to distribute or improve it.  Credit to the original
author (me) will be appreciated, but is not strictly required since the
copyright owners are abnormally mild-mannered (and extremely distant;
see Acknowledgments, below.)

Acknowledgments:

   The opening dialogue, in which you chose your computer opponent,
   is freely adapted from Alexei Panshin's long out-of-print, and
   now classic, "Star Well" travelogues.  Scholars of computer history
   will recognize many allusions to this same opus in various passages
   of Mike Goetz's 550-point Adventure (especially in the Ice Caverns!).

   The Xochitl Sodality, which owns the copyright on Gammon IV, is a
   philanthropic society first publicized by Panshin.  Persons who wish
   to obtain information on site licensing for Gammon IV should contact
   the Monist Association imaginary properties secretary at the following
   address:
                      Monist Association I.P.S.
                      c/o Xochitl Sodality
                      Semichastny House
                      Delbalso, Nashuite Empire


*/

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