將AX寄存器中的16位數分成4組，每組4位，然後把這四組數分別放在AL，BL,CL和DL中

.model small
.386
.data

.CODE
START:
mov ax,@data
mov ds,ax

mov ax,1234h
push ax
shr ax,4
mov bl,al
and bl,0fh
shr ax,4
mov cl,al
and cl,0fh
shr ax,4
mov bl,al
and bl,0fh
shr ax,4
mov cl,al
and cl,0fh
shr ax,4
mov dl,al
and dl,0fh
pop ax
and al,0fh

mov ah,4ch
int 21h
;給Ax 賦值 1234h 結果爲al＝4h bl＝3h cl＝2h dl＝1h
CODE ENDS
END START