1984-12-17 11:03:13 +00:00
|
|
|
.define Sbi4
|
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 subtracts two fourbyte signed integers.
|
|
|
|
|
|
|
|
|
|
|
|
Sbi4:
|
|
|
|
jsr Addsub ! initiate addresses
|
|
|
|
sec
|
|
|
|
1: lda (ADDR+2),y ! get lowbyte+y first operand
|
|
|
|
sbc (ADDR),y ! subtract lowbyte+y second operand
|
|
|
|
sta (ADDR+2),y ! put on stack lowbyte+y result
|
|
|
|
iny
|
|
|
|
inx
|
|
|
|
bne 1b
|
|
|
|
rts
|
|
|
|
|
|
|
|
|