Routines
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B77F: Generate Random Number
Pick a number below the limit in A.
Input
A Maximum value of generated number
GenerateRandomNumber B77F PUSH BC Remember the caller's registers.
B780 LD C,A Remember the upper limit.
B781 CALL FetchFrames Call FetchFrames to read the frame counter.
B784 LD B,A Use the frame counter as the spin count.
B785 LD A,C
GenerateRandomNumber_Loop B786 DEC A Count down inside the limit.
B787 JR NZ,GenerateRandomNumber_Next
B789 LD A,C
GenerateRandomNumber_Next B78A DJNZ GenerateRandomNumber_Loop Count down B and repeat from GenerateRandomNumber_Loop until the count is exhausted.
B78C DEC A Step the count in A down.
B78D POP BC Restore the caller's BC from the stack, leaving the random number in A.
B78E RET Return.
View the equivalent code in;
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