Routines
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6F2F: Multiply A By DE
Used by the routine at HandlerAccelerate.
Multiplies A by DE, by adding DE to the result for each bit of A which is set.
Input
A The first number
DE The second number
Output
HL Result
MultiplyAByDE 6F2F LD HL,$0000 HL=0000.
6F32 LD B,$08 Set the bit counter to 08.
MultiplyAByDE_Loop 6F34 ADD HL,HL Shift the result left.
6F35 RLCA Rotate the next bit of A into the carry flag.
6F36 JR NC,MultiplyAByDE_Next Jump to MultiplyAByDE_Next if the bit is not set.
6F38 ADD HL,DE Add DE to the result.
MultiplyAByDE_Next 6F39 DJNZ MultiplyAByDE_Loop Decrease the bit counter by one and loop back to MultiplyAByDE_Loop until all 08 bits have been used.
6F3B RET Return.
View the equivalent code in;
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