22 lines
416 B
ArmAsm
22 lines
416 B
ArmAsm
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.define Sbi2
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! This subroutine subtracts two twobyte signed integers
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! and returnes the result in registerpair AX.
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Sbi2:
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stx ARTH ! save second operand (lowbyte)
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sta ARTH+1 ! save second operand (highbyte)
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jsr Pop
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pha
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sec
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txa ! get first operand (lowbyte)
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sbc ARTH ! subtract second operand (lowbyte)
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tax
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iny
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pla ! get first operand (highbyte)
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sbc ARTH+1 ! subtract second operand (highbyte)
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rts
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