21 lines
470 B
ArmAsm
21 lines
470 B
ArmAsm
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.define Adi4
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! This subroutine adds two fourbyte integers, which are on the stack.
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! The addresses are initiated by the subroutine Addsub.
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! Also the loopvariable (register X) is initiated by that routine.
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! The result is pushed back onto the stack
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Adi4:
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jsr Addsub ! initiate addresses
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clc
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1: lda (ADDR+2),y ! get byte first operand
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adc (ADDR),y ! add to byte second operand
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sta (ADDR+2),y ! push on real stack
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iny
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inx
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bne 1b ! do it 4 times
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rts
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