munch - munching squares screen hack
munch [-display host:display.screen] [-foreground color] [-background color] [-window]
[-root] [-mono] [-install] [-visual visual] [-delay seconds] [-xor] [-noxor] [-shift]
[-noshift] [-logminwidth minimum width]
The munch program preforms the munching squares hack until killed. It picks square size,
position, and gravity randomly; configurable options are listed below.
The munching squares hack cosists 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 dis-
covered by Jackson Wright in 1962 and took 5 instructions of PDP-6 code.
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 a private colormap for the window.
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.
How long to wait before starting over. Default 5 seconds.
-xor Use the XOR drawing function. (Default.)
-no-xor Don't use the XOR drawing function.
-shift Start drawing the square at weird starting points. (Default.)
Don't shift and start drawing the square at weird starting points.
The logarithm (base 2) of the minimum with of a square (must be a power of 2, or
some parts of the square aren't.)
DISPLAY to get the default host and display number.
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,
Quoted from HAKMEM, for historical interest. As that document says, "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.
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 (C) 1997 by Tim Showalter. 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.
Tim Showalter <email@example.com>, 17-Jun-97, based on what's in the Jargon File and
stealing stuff from existing xscreensaver modules.
X Version 11 17-Jun-97 XScreenSaver(1)