NAME

       munch - munching squares

SYNOPSIS

       munch [--display host:display.screen] [--foreground color] [--background color] [--window]
       [--root]  [--window-id  number][--mono]  [--install]  [--visual  visual]  [--delay  usecs]
       [--xor]  [--noxor]  [--clear  number] [--simul number] [--classic | --mismunch | --random]
       [--fps]

DESCRIPTION

       The munch program performs the munching squares hack.  It picks square size, position, and
       gravity  randomly.   It also displays a creatively broken misimplementation of the classic
       algorithm.

       The munching squares hack consists of drawing Y = X XOR T for a range of X and T over  and
       over  until  all  the  possible  combinations  of X and T have come up.  It was reportedly
       discovered by Jackson Wright in 1962 and took 5 instructions of PDP-6 code.

OPTIONS

       munch accepts the following options:

       --window
               Draw on a newly-created window.  This is the default.

       --root  Draw on the root window.

       --window-id number
               Draw on the specified window.

       --mono  If on a color display, pretend we're on a monochrome display.

       --install
               Install a private colormap for the window.

       --visual visual
               Specify which visual to use.  Legal values are the name of a visual class, or  the
               id number (decimal or hex) of a specific visual.

       --delay usecs
               The delay between steps of the animation, in microseconds.  Default: 2500.

       --xor   Use the XOR drawing function.  This is the default.

       --no-xor
               Don't use the XOR drawing function.

       --clear number
               Number of squares to misdraw before clearing the display.  Default: 65.

       --simul number
               Number of squares to misdraw simultaneously.  Default: 5.

       --classic
               Draw classic munching squares only.

       --mismunch
               Draw "mismunch" only.

       --random
               Do one or the other.

       --fps   Display the current frame rate and CPU load.

ENVIRONMENT

       DISPLAY to get the default host and display number.

       XENVIRONMENT
               to  get  the name of a resource file that overrides the global resources stored in
               the RESOURCE_MANAGER property.

       XSCREENSAVER_WINDOW
               The window ID to use with --root.

HISTORY

       HAKMEM: MIT AI Memo 239, Feb. 29, 1972.  Beeler, M., Gosper, R.W., and Schroeppel, R.

       "Unless otherwise stated, all computer programs are in PDP-6/10 assembly language."

   ITEM 146: MUNCHING SQUARES
       Another simple display program. It is thought that this was discovered by  Jackson  Wright
       on the RLE PDP-1 circa 1962.

            DATAI 2
            ADDB 1,2
            ROTC 2,-22
            XOR 1,2
            JRST .-4

       2=X, 3=Y. Try things like 1001002 in data switches. This also does interesting things with
       operations other than XOR, and rotations other than -22. (Try IOR; AND; TSC; FADR; FDV(!);
       ROT -14, -9, -20, ...)

   ITEM 147 (Schroeppel):
       Munching  squares  is  just  views  of the graph Y = X XOR T for consecutive values of T =
       time.

   ITEM 148 (Cohen, Beeler):
       A modification to munching squares which reveals them in frozen states through opening and
       closing curtains: insert FADR 2,1 before the XOR. Try data switches =

            4000,,4    1000,,2002    2000,,4    0,,1002

       (Notation: <left half>,,<right half>)
       Also try the FADR after the XOR, switches = 1001,,1.

SEE ALSO

       X(1), xscreensaver(1),
       https://www.inwap.com/pdp10/hbaker/hakmem/hakmem.html

COPYRIGHT

       Copyright © 1997 Tim Show alter.
       Copyright © 2004 Steven Hazel.
       Copyright © 1992-2008 Jamie Zawinski.

       Permission  to use, copy, modify, distribute, and sell this software and its documentation
       for any purpose is hereby granted without fee, provided that the  above  copyright  notice
       appear in all copies and that both that copyright notice and this permission notice appear
       in supporting documentation.  No representations are made about the  suitability  of  this
       software for any purpose.  It is provided "as is" without express or implied warranty.