assume cs:code,ds:data
data segment
db'Welcome to masm!'
data ends
;定义16个字节存放字符
code segment
start: mov ax,data
mov ds,ax
mov bx,0
mov si,0
mov di,0
mov ax,0b86eh ;这个是我计算出的中间位置因为屏幕上
;显示25行取12行为中间,
...