总是会出现未定义的错误
stack           segment
                db      256 dup(?)
stack           ends
code            segment
move_face       proc    far
                assume  cs:code,ss:stack
start:          push    ds
                sub     ax,ax
                push    ax
                mov     ah,15
                int     10h
                mov     ah,0
                mov     al,1
                int     10h
                mov     cx,1
                mov     dx,0
                sti
move_cursor:    mov     ah,2
                int     10h
                mov     al,1
                mov     ah,10
                int     10h
                call    delay
                sub     al,al
                mov     ah,10
                int     10h
                inc     dh
                inc     dl
                cmp     dh,25h
                jne     move_cursor
                ret
move_face       endp
delay           proc
                push    bx
                push    cx
                push    dx
                mov     ah,0
                int     1ah
                add     dx,9
                mov     bx,dx
redo:           int     1ah
                cmp     dx,bx
                jne     redo
                pop     dx
                pop     cx
                pop     bx
                ret
delay           endp
code            ends
                end     start