要求在屏幕8行3列用绿色显示DATA段中的字符串
assume cs:code
data segment
db 'welcome to masm! ',0
data ends
code segment
start: mov dh,8
mov dl,3
mov cl,2
mov ax,data
mov ds,ax
mov si,0
call show_str
mov ax,4c00h
int 21h
show_str:push ax
push di
push dx
push cx
mov ax,0b000h
mov es,ax
mov al,0a0h
dec dh
mul dh
mov ah,0
mov bp,ax
mov al,2
dec dl
mul dl
add bp,ax
mov di,0
s: mov cl,[bx]
mov ch,0
jcxz ok
mov al,02h
mov es:[bp+di],cl
mov es:[bp+di+1],al
inc cx
add di,2
inc bx
loop s
ok: pop cx
pop dx
pop di
pop ax
ret
code ends
end start
其中SHOW_STR是我写的，但运行完什么都没看到，请问是哪有问题？