Introduction - If you have any usage issues, please Google them yourself
dat segment
import db input a 4 bit hex:$
output db the equal number=$
err db wrong number$
dat ends
cod segment
assume cs:cod,ds:dat
start: mov ax,dat
mov ds,ax
mov bx,0
call rec
call enter
call disp
rec proc
mov ah,1
int 21h
cmp al,odh
jz exit
cmp al,30h
jb err
cmp al,39h
jbe save
cmp al,