汇编语言王爽实验14问题

为什么通不过编译?

assume ds:data,ss:stack,cs:code

data segment

time: db "20??/??/?? ??:??:??",0

routine: db 9,8,7,4,2,0
data ends

stack segment
db 12 dup (0)
stack ends

code segment
start:

     mov ax,data
     mov ds,ax
     mov si,offset time+2
     mov di,offset routine 
     mov ax,stack
     mov ss,ax
     mov sp,12
     mov cx,6

lp:

push cx

mov al,ds:[di]
out 70h,al
in al,71h

     mov ah,al
     mov cl,4
     shr ah,cl
     and al,00001111b
     add ah,30h
     add al,30h


     mov byte ptr ds:[si],ah
     mov byte ptr ds:[si+1],al
     inc di
     add si,3
     pop cx
     loop lp

     mov ax,0b800h
     mov es,ax
     mov di,160*12 
     mov si,offset time

show: mov cl,[si]
mov ch,0
jcxz ok
mov es:[di],cl
inc si
inc di
inc di
jmp show

ok: mov ax,4c00h
int 21h

code ends
end start

http://blog.csdn.net/u010452022/article/details/49640199