23 lines
331 B
ArmAsm
23 lines
331 B
ArmAsm
.define TestFFh
|
|
|
|
! This subroutine tests if the value on top of the stack is <= 256.
|
|
! It is used if the istruction argument is on top of the stack.
|
|
! The value is saved in Y.
|
|
|
|
|
|
TestFFh:
|
|
cmp #2
|
|
bpl 1f ! value > 256
|
|
cmp #0
|
|
beq 2f
|
|
cpx #0
|
|
bne 1f ! value is zero
|
|
2: dex
|
|
txa
|
|
tay
|
|
rts
|
|
1: ldx #Eoddz
|
|
lda #0
|
|
jsr Trap
|
|
|
|
|