汇编编程 将四位十六见制数转换为等值二进制数并显示

DATA SEGMENT
MES DB 'enter a hex data:$'
DATA ENDS
;************************************************************
CODE SEGMENT
;------------------------------------------------------------
HTOB PROC FAR
ASSUME CS:CODE ,DS:DATA

MOV AX,DATA
MOV DS,AX
START:
MOV AH,9
LEA DX,MES
INT 21H
PUSH DS
SUB AX,AX
PUSH AX
CALL INPUT
CALL CRLF
CALL PRINT
CALL CRLF
JMP START
RET
HTOB ENDP
;-----------------------------------------------------------
INPUT PROC NEAR
MOV BX,0