.MODEL SMALL
.DATA
M1 DB 0AH,0DH,'Type a character : ','$'
M2 DB 0AH,0DH,'The ASCII Code of '
C1 DB ?,' In Hexa is ','$'
.CODE
MAIN PROC
MOV AX,@DATA                         ;intialize DS
MOV DS,AX

BEGIN: MOV AH,9
LEA DX,M1
INT 21h
MOV AH,1                             ;read the char.
INT 21H
CMP AL,0DH
JE OUT_
MOV C1,AL                            ;store the char.
MOV BL,AL
MOV AH,9
LEA DX,M2
INT 21H
MOV CL,4
SHR C1,CL
ADD C1,30H
MOV DL,C1
JMP EXE1
continue:
AND BL,0FH
CMP BL,9
JG ERROR_
ADD BL,30H
MOV DL,BL
JMP EXE2
EXE1: MOV AH,2
INT 21H
JMP continue
EXE2: MOV AH,2
INT 21H
JMP BEGIN                                ;ask if we want to do it again

ERROR_: ADD BL,37H
MOV DL,BL
MOV AH,2
INT 21H

JMP BEGIN                                ;ask if we want to do it again
OUT_: MOV AH,4CH
INT 21H
MAIN ENDP
END MAIN