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38 lines
669 B
C
38 lines
669 B
C
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/* rand.c - kluges a random number generator with addition & overflow */
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#include "portab.h"
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#define NSEEDS 7
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MLOCAL WORD _seeds[NSEEDS] =
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{ 0, 24213, 12345, 4622, 2143, 32010, 7942 };
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MLOCAL WORD _seedptr=0;
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WORD rand() /* CLEAR FUNCTION ***********/
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{
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REG UWORD tot, ii;
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for( tot=0, ii=0; ii<NSEEDS; ii++)
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tot += _seeds[ii]; /* ignore overflow */
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if( ++_seedptr >= NSEEDS )
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_seedptr = 0;
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_seeds[_seedptr] = tot;
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return( tot >> 1 ); /* ignore lo bit because of addition */
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}
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WORD srand(seed1) /* CLEAR FUNCTION ***********/
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int seed1;
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{
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REG WORD ncs;
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_seeds[0] = seed1;
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for( ncs = seed1&077; ncs; ncs-- )
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rand();
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return(rand());
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}
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