cpct_setSeed_lcg_u8

Sets the random seed used by cpct_getRandom_lcg_u8.

C Definition

void cpct_setSeed_lcg_u8 (u8 seed) __z88dk_fastcall;

Input Parameters (1 byte)

(1B L) seed

New seed to be set for the random number generator.

Assembly call (Input parameter on L)

call cpct_setSeed_lcg_u8_asm

Parameter Restrictions

seed New seed byte that will be set internally in the random number generator. There is no restriction about the value of this byte.

Known limitations

This function will not work from a ROM. It does not specifically use self-modifying code, but indirectly modifies the code of cpct_getRandom_lcg_u8.

Details

This function sets the random seed that cpct_getRandom_lcg_u8 uses internally for generating pseudo-random numbers. This can be used to randomize the start of the pseudo-random sequence or to make it predictable (setting the same seed again).

Please, do read documentation from cpct_getRandom_lcg_u8 for more details about how this random generator works.

Destroyed Register values

Required memory

2 bytes

Time Measures

   Case     | microSecs (us) | CPU Cycles
-----------------------------------------
   Any      |       7        |    28
-----------------------------------------

Credits

Random generation original code comes from Fast RND, which can be found published by z80-info. The original code is reported to be from Spectrum ROM.