bcd_aas.asm

来自「介绍用Java解析网络数据的三种特殊方法」· 汇编 代码 · 共 32 行

; This is an example of AAS
; instruction, it is used to
; subtract huge BCD numbers.

#make_COM#

ORG	100h

; make 5 - 9
; AL = 0FCh (not BCD form)
MOV	AL, 05h
MOV	BL, 09h
SUB	AL, BL


; convert to BCD,
; AL = 6
; (and 1 is borrowed from AH,
;  like calculating 15 - 9):
AAS

; convert to printable symbol:
OR	AL, 30h

; print char in AL using BIOS
; teletype function:
MOV	AH, 0Eh
INT	10h

RET

END