| 1 | .de EX \"Begin example |
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| 2 | .ne 5 |
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| 3 | .if n .sp 1 |
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| 4 | .if t .sp .5 |
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| 5 | .nf |
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| 6 | .in +.5i |
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| 7 | .. |
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| 8 | .de EE |
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| 9 | .fi |
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| 10 | .in -.5i |
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| 11 | .if n .sp 1 |
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| 12 | .if t .sp .5 |
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| 13 | .. |
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| 14 | .TH XScreenSaver 1 "17-Jun-97" "X Version 11" |
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| 15 | .SH NAME |
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| 16 | munch - munching squares screen hack |
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| 17 | .SH SYNOPSIS |
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| 18 | .B munch |
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| 19 | [\-display \fIhost:display.screen\fP] [\-foreground \fIcolor\fP] |
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| 20 | [\-background \fIcolor\fP] [\-window] [\-root] [\-mono] [\-install] |
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| 21 | [\-visual \fIvisual\fP] [\-delay \fIseconds\fP] [\-xor] [\-noxor] [\-shift] |
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| 22 | [\-noshift] [\-logminwidth \fIminimum width\fP] |
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| 23 | .SH DESCRIPTION |
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| 24 | The |
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| 25 | .I munch |
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| 26 | program preforms the munching squares hack until killed. It picks square |
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| 27 | size, position, and gravity randomly; configurable options are listed |
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| 28 | below. |
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| 29 | .PP |
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| 30 | The munching squares hack cosists of drawing Y = X XOR T for a range of X |
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| 31 | and T over and over until all the possible combinations of X and T have |
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| 32 | come up. It was reportedly discovered by Jackson Wright in 1962 and took 5 |
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| 33 | instructions of PDP-6 code. |
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| 34 | .SH OPTIONS |
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| 35 | .I munch |
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| 36 | accepts the following options: |
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| 37 | .TP 8 |
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| 38 | .B \-window |
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| 39 | Draw on a newly-created window. This is the default. |
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| 40 | .TP 8 |
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| 41 | .B \-root |
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| 42 | Draw on the root window. |
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| 43 | .TP 8 |
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| 44 | .B \-mono |
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| 45 | If on a color display, pretend we're on a monochrome display. |
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| 46 | .TP 8 |
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| 47 | .B \-install |
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| 48 | Install a private colormap for the window. |
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| 49 | .TP 8 |
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| 50 | .B \-visual \fIvisual\fP |
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| 51 | Specify which visual to use. Legal values are the name of a visual class, |
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| 52 | or the id number (decimal or hex) of a specific visual. |
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| 53 | .TP 8 |
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| 54 | .B \-delay \fIseconds\fP |
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| 55 | How long to wait before starting over. Default 5 seconds. |
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| 56 | .TP 8 |
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| 57 | .B \-xor |
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| 58 | Use the XOR drawing function. (Default.) |
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| 59 | .TP 8 |
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| 60 | .B \-no\-xor |
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| 61 | Don't use the XOR drawing function. |
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| 62 | .TP 8 |
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| 63 | .B \-shift |
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| 64 | Start drawing the square at weird starting points. (Default.) |
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| 65 | .TP 8 |
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| 66 | .B \-no\-shift |
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| 67 | Don't shift and start drawing the square at weird starting points. |
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| 68 | .TP 8 |
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| 69 | .B \-logminwidth \fIminimum\-width\fP |
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| 70 | The logarithm (base 2) of the minimum with of a square (must be a power of |
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| 71 | 2, or some parts of the square aren't.) |
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| 72 | .SH ENVIRONMENT |
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| 73 | .PP |
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| 74 | .TP 8 |
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| 75 | .B DISPLAY |
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| 76 | to get the default host and display number. |
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| 77 | .TP 8 |
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| 78 | .B XENVIRONMENT |
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| 79 | to get the name of a resource file that overrides the global resources |
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| 80 | stored in the RESOURCE_MANAGER property. |
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| 81 | .SH SEE ALSO |
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| 82 | .BR X (1), |
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| 83 | .BR xscreensaver (1), |
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| 84 | .BR http://www.inwap.com/pdp10/hbaker/hakmem/hakmem.html, |
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| 85 | .BR http://www.comedia.com/Hot/jargon_3.0/JARGON_M/MUNCHSQR.HTML |
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| 86 | .SH HISTORY |
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| 87 | Quoted from HAKMEM, for historical interest. As that document says, "Unless |
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| 88 | otherwise stated, all computer programs are in PDP-6/10 assembly language." |
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| 89 | .TP 8 |
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| 90 | ITEM 146: MUNCHING SQUARES |
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| 91 | Another simple display program. It is thought that this was discovered by |
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| 92 | Jackson Wright on the RLE PDP-1 circa 1962. |
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| 93 | |
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| 94 | .EX |
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| 95 | DATAI 2 |
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| 96 | ADDB 1,2 |
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| 97 | ROTC 2,-22 |
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| 98 | XOR 1,2 |
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| 99 | JRST .-4 |
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| 100 | .EE |
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| 101 | .RS 8 |
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| 102 | 2=X, 3=Y. Try things like 1001002 in data switches. This also does |
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| 103 | interesting things with operations other than XOR, and rotations other |
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| 104 | than -22. (Try IOR; AND; TSC; FADR; FDV(!); ROT -14, -9, -20, ...) |
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| 105 | .RE |
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| 106 | .TP 8 |
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| 107 | ITEM 147 (Schroeppel): |
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| 108 | Munching squares is just views of the graph Y = X XOR T for consecutive |
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| 109 | values of T = time. |
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| 110 | .TP 8 |
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| 111 | ITEM 148 (Cohen, Beeler): |
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| 112 | A modification to munching squares which reveals them in frozen states |
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| 113 | through opening and closing curtains: insert FADR 2,1 before the XOR. Try |
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| 114 | data switches = |
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| 115 | |
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| 116 | .EX |
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| 117 | 4000,,4 1000,,2002 2000,,4 0,,1002 |
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| 118 | .EE |
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| 119 | .RS 8 |
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| 120 | (Notation: <left half>,,<right half>) |
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| 121 | |
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| 122 | Also try the FADR after the XOR, switches = 1001,,1. |
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| 123 | .SH COPYRIGHT |
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| 124 | Copyright \(co 1997 by Tim Showalter. Permission to use, copy, modify, |
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| 125 | distribute, and sell this software and its documentation for any purpose is |
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| 126 | hereby granted without fee, provided that the above copyright notice appear |
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| 127 | in all copies and that both that copyright notice and this permission notice |
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| 128 | appear in supporting documentation. No representations are made about the |
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| 129 | suitability of this software for any purpose. It is provided "as is" without |
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| 130 | express or implied warranty. |
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| 131 | .SH AUTHOR |
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| 132 | Tim Showalter <tjs@andrew.cmu.edu>, 17-Jun-97, based on what's in the |
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| 133 | Jargon File and stealing stuff from existing xscreensaver modules. |
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