1munch(6x) XScreenSaver manual munch(6x)
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6 munch - munching squares
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9 munch [--display host:display.screen] [--foreground color] [--back‐
10 ground color] [--window] [--root] [--window-id number][--mono] [--in‐
11 stall] [--visual visual] [--delay usecs] [--xor] [--noxor] [--clear
12 number] [--simul number] [--classic | --mismunch | --random] [--fps]
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15 The munch program performs the munching squares hack. It picks square
16 size, position, and gravity randomly. It also displays a creatively
17 broken misimplementation of the classic algorithm.
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19 The munching squares hack consists of drawing Y = X XOR T for a range
20 of X and T over and over until all the possible combinations of X and T
21 have come up. It was reportedly discovered by Jackson Wright in 1962
22 and took 5 instructions of PDP-6 code.
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25 munch accepts the following options:
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27 --window
28 Draw on a newly-created window. This is the default.
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30 --root Draw on the root window.
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32 --window-id number
33 Draw on the specified window.
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35 --mono If on a color display, pretend we're on a monochrome display.
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37 --install
38 Install a private colormap for the window.
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40 --visual visual
41 Specify which visual to use. Legal values are the name of a
42 visual class, or the id number (decimal or hex) of a specific
43 visual.
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45 --delay usecs
46 The delay between steps of the animation, in microseconds. De‐
47 fault: 2500.
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49 --xor Use the XOR drawing function. This is the default.
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51 --no-xor
52 Don't use the XOR drawing function.
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54 --clear number
55 Number of squares to misdraw before clearing the display. De‐
56 fault: 65.
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58 --simul number
59 Number of squares to misdraw simultaneously. Default: 5.
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61 --classic
62 Draw classic munching squares only.
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64 --mismunch
65 Draw "mismunch" only.
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67 --random
68 Do one or the other.
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70 --fps Display the current frame rate and CPU load.
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73 DISPLAY to get the default host and display number.
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75 XENVIRONMENT
76 to get the name of a resource file that overrides the global
77 resources stored in the RESOURCE_MANAGER property.
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79 XSCREENSAVER_WINDOW
80 The window ID to use with --root.
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83 HAKMEM: MIT AI Memo 239, Feb. 29, 1972. Beeler, M., Gosper, R.W., and
84 Schroeppel, R.
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86 "Unless otherwise stated, all computer programs are in PDP-6/10 assem‐
87 bly language."
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89 ITEM 146: MUNCHING SQUARES
90 Another simple display program. It is thought that this was discovered
91 by Jackson Wright on the RLE PDP-1 circa 1962.
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93 DATAI 2
94 ADDB 1,2
95 ROTC 2,-22
96 XOR 1,2
97 JRST .-4
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99 2=X, 3=Y. Try things like 1001002 in data switches. This also does in‐
100 teresting things with operations other than XOR, and rotations other
101 than -22. (Try IOR; AND; TSC; FADR; FDV(!); ROT -14, -9, -20, ...)
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103 ITEM 147 (Schroeppel):
104 Munching squares is just views of the graph Y = X XOR T for consecutive
105 values of T = time.
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107 ITEM 148 (Cohen, Beeler):
108 A modification to munching squares which reveals them in frozen states
109 through opening and closing curtains: insert FADR 2,1 before the XOR.
110 Try data switches =
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112 4000,,4 1000,,2002 2000,,4 0,,1002
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114 (Notation: <left half>,,<right half>)
115 Also try the FADR after the XOR, switches = 1001,,1.
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118 X(1), xscreensaver(1),
119 https://www.inwap.com/pdp10/hbaker/hakmem/hakmem.html
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122 Copyright © 1997 Tim Show alter.
123 Copyright © 2004 Steven Hazel.
124 Copyright © 1992-2008 Jamie Zawinski.
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126 Permission to use, copy, modify, distribute, and sell this software and
127 its documentation for any purpose is hereby granted without fee, pro‐
128 vided that the above copyright notice appear in all copies and that
129 both that copyright notice and this permission notice appear in sup‐
130 porting documentation. No representations are made about the suitabil‐
131 ity of this software for any purpose. It is provided "as is" without
132 express or implied warranty.
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136X Version 11 6.06-1.fc37 (12-Dec-2022) munch(6x)