l4-69.asm

汇编经典例程,是学习微机原理的好帮手,包括循环 分支等结构

DATA SEGMENT
BUF  DB 10 DUP(?) 
DATA ENDS
CODE  SEGMENT
ASSUME CS:CODE,DS:DATA
START:MOV AX, DATA
MOV DS,AX 
MOV BX,0FFFFH
MOV  SI, OFFSET BUF
MOV  CH,4
MOV CL,4
NEXT: 
ROL BX, CL
MOV AL,BL
AND AL,0FH
ADD AL,30H
CMP AL,3AH
JL  STORE
ADD AL,7
STORE:MOV [SI],AL
MOV AH,2
MOV DL, AL
INT 21H
INC SI
DEC  CH
JNZ   NEXT
MOV AH, 4CH
INT 21H
CODE ENDS
END START