mirror of
https://github.com/irmen/prog8.git
synced 2024-11-29 17:50:35 +00:00
21 lines
419 B
NASM
21 lines
419 B
NASM
|
; just for tests - DISFUNCTIONAL!
|
||
|
|
|
||
|
|
|
||
|
|
math_store_reg .byte 0 ; temporary storage
|
||
|
|
|
||
|
|
|
||
|
|
multiply_bytes .proc
|
||
|
|
; -- multiply 2 bytes A and Y, result as byte in A (signed or unsigned)
|
||
|
|
sta P8ZP_SCRATCH_B1 ; num1
|
||
|
|
sty P8ZP_SCRATCH_REG ; num2
|
||
|
|
lda #0
|
||
|
|
beq _enterloop
|
||
|
|
_doAdd clc
|
||
|
|
adc P8ZP_SCRATCH_B1
|
||
|
|
_loop asl P8ZP_SCRATCH_B1
|
||
|
|
_enterloop lsr P8ZP_SCRATCH_REG
|
||
|
|
bcs _doAdd
|
||
|
|
bne _loop
|
||
|
|
rts
|
||
|
|
.pend
|