编程：在屏幕中间分别显示绿色、绿色红底、白色蓝底的字符串’welcome to masm!’
assume cs:code,ds:data
data segment
db "welcome to masm!"
data ends
code segment
start: mov ax,data
mov ds,ax
mov ax,0b800h
mov es,ax
mov bx,0
mov si,1980
mov cx,16
s: mov al,ds:[bx]
mov ah,02h
mov es:[si],ax
mov ah,24h
mov es:[si+160],ax
mov ah,71h
mov es:[si+320],ax
inc bx
add si,2
loop s
mov ax,4c00h
int 21h
code ends
end start