ack/mach/6500/libem/ngi.s

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1984-12-17 11:03:13 +00:00
.define Ngi2
1987-01-30 18:41:42 +00:00
.sect .text
.sect .rom
.sect .data
.sect .bss
.sect .text
1984-12-17 11:03:13 +00:00
! This subroutine negates the integer in registerpair AX.
! The negation is a one's complement plus one.
Ngi2:
eor #0FFh ! one's complement A
tay
txa
eor #0FFh ! one's complement X
tax
inx ! increment X
bne 1f
iny ! increment A if neccesairy
1: tya
rts