实习第一天

早上实习无事，写了一个用来输出年月日的汇编小程序，源代码如下： 

data segment
  year db "year:$"
  month db " month:$"
  day db " day:$"
data ends

code segment

assume cs:code,ds:data

start:

mov ax,seg year
mov ds,ax
mov dx,offset year
mov ah,09h
int 21h

mov ah,04h
int  1ah
mov bx,cx
mov ch,4
rotate1: mov cl,4
        rol bx,cl
        mov al,bl
        and al,0fh
        add al,30h
        mov dl,al
        mov ah,2
        int 21h
        dec ch
        jnz rotate1

mov ax,seg month
mov ds,ax
mov dx,offset month
mov ah,09h
int 21h

mov ah,04h
int 1ah
mov ch,2
rotate2:mov cl,4
        rol dx,cl
        mov al,dl
        and al,0fh
        add al,30h
        mov dl,al
        mov ah,2
        int 21h
        dec ch
        jnz rotate2

mov ax,seg day
mov ds,ax
mov dx,offset day
mov ah,09h
int 21h

mov ah,04h
int 1ah
mov ch,2
mov cl,8
rol dx,cl
rotate3:mov cl,4
        rol dx,cl
        mov al,dl
        and al,0fh
        add al,30h
        mov dl,al
        mov ah,2
        int 21h
        dec ch
        jnz rotate3

mov ax,4c00h
int 21h

code ends

end start

输出结果：

year:2008  month:3 day:24