Вывод шестнадцатеричного числа

  org 100h
;===========================
 
test_write_word_hex:
  mov dx,1234h
  call write_word_hex
  int 20h
;===========================
 
write_word_hex:
 push dx
 xchg dh,dl
 call write_byte_hex
 xchg dh,dl
 call write_byte_hex
 pop dx
 ret
;=============================
 
write_byte_hex:
 push dx
 mov cl,04
 shr dl,cl
 call write_digit_hex
 and dl,0fh
 call write_digit_hex
 pop dx
 ret
;=============================
 
write_digit_hex:
 push dx
 cmp dl,09
 ja .g
 add dl,30
 jmp .h
.g add dl,37
.h call write_char
 pop dx
 ret
;=============================
 
write_char:
 push ax
 mov ah,02h
 int 21h
 pop ax
 ret

mov bx,1234
mov dl,bh
mov cl,04
shr  dl,cl
cmp dl,09
ja 
add dl,30
jmp 
add dl,37
mov ah,02
int 21
mov dl,bh
and dl,0f
cmp dl,09
ja
add dl,30
jmp 
add dl,37
int 21
mov dl,bl
mov cl,04
shr dl,cl
cmp dl,09
ja 
add dl,30
jmp
add dl,37
int 21
mov dl,bl
and dl,0f
cmp dl,09
ja
add dl,30
jmp 
add dl,37
int 21
int 20

cmp dl,09
 ja .g
 add dl,30h; код'0'
 jmp .h
.g add dl,37h; 0Ah+37h= 41 код A'
.h call write_char