Provided by:
xscreensaver-data-extra_5.08-0ubuntu3_i386 
NAME
munch - munching squares
SYNOPSIS
munch [-display host:display.screen] [-foreground color] [-background
color] [-window] [-root] [-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.
-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.
X(1), xscreensaver(1),
http://www.inwap.com/pdp10/hbaker/hakmem/hakmem.html
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.
COPYRIGHT
Copyright 1997 Tim Showalter.
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, pro-
vided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in sup-
porting documentation. No representations are made about the suitabil-
ity of this software for any purpose. It is provided "as is" without
express or implied warranty.