14 .TH XScreenSaver 1 "17-Jun-97" "X Version 11"
16 munch - munching squares screen hack
19 [\-display \fIhost:display.screen\fP] [\-foreground \fIcolor\fP]
20 [\-background \fIcolor\fP] [\-window] [\-root] [\-mono] [\-install]
21 [\-visual \fIvisual\fP] [\-delay \fImicroseconds\fP] [\-xor] [\-noxor] [\-shift]
22 [\-noshift] [\-logminwidth \fIminimum width\fP]
27 program performs the munching squares hack until killed. It picks square
28 size, position, and gravity randomly; configurable options are listed
31 The munching squares hack consists of drawing Y = X XOR T for a range of X
32 and T over and over until all the possible combinations of X and T have
33 come up. It was reportedly discovered by Jackson Wright in 1962 and took 5
34 instructions of PDP-6 code.
37 accepts the following options:
40 Draw on a newly-created window. This is the default.
43 Draw on the root window.
46 If on a color display, pretend we're on a monochrome display.
49 Install a private colormap for the window.
51 .B \-visual \fIvisual\fP
52 Specify which visual to use. Legal values are the name of a visual class,
53 or the id number (decimal or hex) of a specific visual.
55 .B \-delay \fImicroseconds\fP
56 How long to wait before starting over. Default 5000.
59 Use the XOR drawing function. (Default.)
62 Don't use the XOR drawing function.
65 Start drawing the square at weird starting points. (Default.)
68 Don't shift and start drawing the square at weird starting points.
70 .B \-logminwidth \fIminimum\-width\fP
71 The logarithm (base 2) of the minimum with of a square (must be a power of
72 2, or some parts of the square aren't.)
75 Display the current frame rate and CPU load.
80 to get the default host and display number.
83 to get the name of a resource file that overrides the global resources
84 stored in the RESOURCE_MANAGER property.
88 .BR http://www.inwap.com/pdp10/hbaker/hakmem/hakmem.html,
89 .BR http://www.comedia.com/Hot/jargon_3.0/JARGON_M/MUNCHSQR.HTML
91 Quoted from HAKMEM, for historical interest. As that document says, "Unless
92 otherwise stated, all computer programs are in PDP-6/10 assembly language."
94 ITEM 146: MUNCHING SQUARES
95 Another simple display program. It is thought that this was discovered by
96 Jackson Wright on the RLE PDP-1 circa 1962.
106 2=X, 3=Y. Try things like 1001002 in data switches. This also does
107 interesting things with operations other than XOR, and rotations other
108 than -22. (Try IOR; AND; TSC; FADR; FDV(!); ROT -14, -9, -20, ...)
111 ITEM 147 (Schroeppel):
112 Munching squares is just views of the graph Y = X XOR T for consecutive
115 ITEM 148 (Cohen, Beeler):
116 A modification to munching squares which reveals them in frozen states
117 through opening and closing curtains: insert FADR 2,1 before the XOR. Try
121 4000,,4 1000,,2002 2000,,4 0,,1002
124 (Notation: <left half>,,<right half>)
126 Also try the FADR after the XOR, switches = 1001,,1.
128 Copyright \(co 1997 by Tim Showalter. Permission to use, copy, modify,
129 distribute, and sell this software and its documentation for any purpose is
130 hereby granted without fee, provided that the above copyright notice appear
131 in all copies and that both that copyright notice and this permission notice
132 appear in supporting documentation. No representations are made about the
133 suitability of this software for any purpose. It is provided "as is" without
134 express or implied warranty.
136 Tim Showalter <tjs@andrew.cmu.edu>, 17-Jun-97, based on what's in the
137 Jargon File and stealing stuff from existing xscreensaver modules.