Generates a random number. This is a bit odd... like all inline functions it takes a numeric argument, but in RNDs case this argument is mostly ignored. If it's a negative number it skips a couple of stages of reseeding RND_SEED.
| If tghe argument in FACCUM is negative, then skip over the | ||||
| 0C5F | EF | Rnd | RST FTestSign | |
| 0C60 | FA7C0C | JM 0C7C | ||
| Load the seed into FACCUM. | ||||
| 0C63 | 21910C | LXI H,RND_SEED | ||
| 0C66 | CD0F0A | CALL FLoadFromMem | ||
| 0C69 | C8 | RZ | ||
| Multiply seed by 11,879,546. | ||||
| 0C6A | 013598 | LXI B,9835 | ||
| 0C6D | 117A44 | LXI D,447A | ||
| 0C70 | CDE508 | CALL FMul+2 | ||
| Add 0.00000003927678 | ||||
| 0C73 | 012868 | LXI B,6828 | ||
| 0C76 | 1146B1 | LXI D,B146 | ||
| 0C79 | CD1208 | CALL FAdd+2 | ||
| Swap first and third mantissa bytes. | ||||
| 0C7C | CD1D0A | CALL FCopyToBCDE | ||
| 0C7F | 7B | MOV A,E | ||
| 0C80 | 59 | MOV E,C | ||
| 0C81 | 4F | MOV C,A | ||
|
Set FTEMP_SIGN to 0x80 to indicate to FNormalise that it doesn't need to change the sign. Also set FACCUM's exponent to 0 so the result, when normalised, will be less than 1. | ||||
| 0C82 | 3680 | MVI M,80 | ||
| 0C84 | 2B | DCX H | ||
| 0C85 | 46 | MOV B,M | ||
| 0C86 | 3680 | MVI M,80 | ||
| 0C88 | CD5E08 | CALL FNormalise+3 | ||
| Exit via a copy of the result to RND_SEED so it can be used for the next time RND is called. | ||||
| 0C8B | 21910C | LXI H,RND_SEED | ||
| 0C8E | C3290A | JMP FCopyToMem | ||
| Seed for random number generation. | ||||
| 0C91 | 52C74F80 | RND_SEED | 0.811635 | |