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36 lines
488 B
ArmAsm
36 lines
488 B
ArmAsm
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; Ullrich von Bassewitz, 05.08.1998
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; CC65 runtime: long sub
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;
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;
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; EAX = TOS - EAX
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;
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.export tossubeax
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.import addysp1
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.importzp sp, sreg
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tossubeax:
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ldy #0
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sec
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eor #$FF
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adc (sp),y ; byte 0
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pha ; Save low byte
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iny
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txa
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eor #$FF
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adc (sp),y ; byte 1
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tax
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iny
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lda (sp),y
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sbc sreg ; byte 2
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sta sreg
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iny
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lda (sp),y
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sbc sreg+1 ; byte 3
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sta sreg+1
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pla ; Restore byte 0
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jmp addysp1 ; Drop TOS
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