l4-74.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

CODE SEGMENT
ASSUME CS:CODE
START:MOV AL,12H
CALL BCD2BIN
MOV BX,AX
CALL DISPBXB
MOV AH,4CH
INT 21H
BCD2BIN   PROC  NEAR 
PUSH   CX
MOV    CH, AL
AND    CH,0FH       
MOV   CL, 4
SHR   AL,CL
MOV   CL, 10
MUL   CL
ADD   AL, CH
POP   CX
RET
BCD2BIN   ENDP
DISPBXB PROC NEAR
        MOV CX,16
    LP: ROL BX,1
        JC D1
        MOV DL,30H
        JMP OUTP
    D1: MOV DL,31H
  OUTP：MOV AH,2
        INT 21H
        LOOP LP
        MOV DL,'B'
        MOV AH,2
        INT 21H
        RET
DISPBXB ENDP
CODE ENDS
END START