random.asm File Reference

Namespaces
namespace	Random
	Random number generator module.

Functions
macro	PseudoRandom ()
	This macro generates a pseudo-random number.
macro	InitSid ()
macro	GetRandomNumberFromSid ()

Function Documentation

PseudoRandom()

macro PseudoRandom

(

)

This macro generates a pseudo-random number.

The macro uses the Linear Feedback Shift Register (LFSR) method to generate a pseudo-random number. It is guaranteed to create a sequence touching every element from 0 to $ff just once. Seed must be provided in accumulator and can be from 0 to $ff. Output number will be available in the accumulator. It performs an arithmetic shift left (ASL) on the accumulator. If the result is zero or if the carry flag is set, it skips the exclusive OR (EOR) operation. Otherwise, it performs the EOR operation with the hexadecimal value 0x1D.

Note

The generated pseudo-random number is stored in the accumulator (.A register).

Remarks

Register .A must contain seed and will contain pseudo random number generated. Flags N, Z and C will be affected.

Use c128lib_PseudoRandom in random-global.asm

Since

0.1.0

InitSid()

macro InitSid

(

)

Init random number generator based on the Sid chip. When used, voice 3 of Sid chip can't be used for playback sounds.

Remarks

Register .A will be changed. Flags N and Z will be affected.

See also

GetRandomNumberFromSid

Note

Use c128lib_InitSid in random-global.asm

Since

0.1.0

GetRandomNumberFromSid()

macro GetRandomNumberFromSid

(

)

Get a new random number from the Sid chip and puts it into the .A register. Random numbers are continuously generated so each call gives a new random number. Generetor must be initialized with InitSid().

Remarks

Register .A will be changed. Flags N and Z will be affected.

See also

InitSid

Note

Use c128lib_GetRandomNumberFromSid in random-global.asm

Since

0.1.0