Posted By
IstvanV
on 2011-02-28
09:01:11
|  Re: Random for Real
Another version of the above routine, with a 23-bit LFSR. The quality is improved, although still not quite perfect. However, it is slower (40 cycles without the JSR and RTS, but maybe it can be optimized).
. 2100 A5 D1 LDA $D1
. 2102 AA TAX
. 2103 4A LSR
. 2104 A5 D0 LDA $D0
. 2106 4D 02 FF EOR $FF02
. 2109 85 D1 STA $D1
. 210B 6A ROR
. 210C 85 D0 STA $D0
. 210E 8A TXA
. 210F 0A ASL
. 2110 A5 D2 LDA $D2
. 2112 2A ROL
. 2113 86 D2 STX $D2
. 2115 45 D0 EOR $D0
. 2117 85 D0 STA $D0
. 2119 60 RTS
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