ex9:在屏幕中央显示 welcome to asm!

assume cs:code,ds:data
data segment
    db "welcome to asm!"
data ends

code segment
start:
    mov ax,data
    mov ds,ax
    mov si,0
    mov bx,0
    mov ax,0b800h
    mov es,ax
    mov di,12*160+32*2
    mov cx,15
  s:mov al,[si]
    mov byte ptr es:[di],al
    inc si
    inc di
    mov byte ptr es:[di],2h
    inc di
    loop s
   
   
    mov ax,4c00h
    int 21h
code ends
end start