.define Ngi2 .sect .text .sect .rom .sect .data .sect .bss .sect .text ! 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