汇编－屏幕任意位置显示相应字符串的小程序

assume cs:code
data segment
db 'welcome to masm!' ;要显示的字符串
data ends
code segment
;DH 存储行号 <=25
;DL 列号 <=80
;CL 显示字符的前景色 背景色
;DS:SI   存储字符串的首地址
;行地址 = (DH-1H)*A0H
;列地址 = (DL-1)*2H
    show_str:              
mov aH,0
mov al,0A0H
mul DH
mov bp,ax
mov ax,0b800H
mov es,ax
mov aH,0
mov al,2
mul dl
mov di,ax
mov ah,0
mov al,cl
s:
mov ch,0H
mov cl,ds:[si]
jcxz p
mov ch,al
mov es:[bp+di],cx
inc si
add di,2H
jmp short s
p:
ret
    begin:
mov cl,01000010B
mov dh,10
mov dl,40
mov ax,data
mov ds,ax
mov si,0
call show_str
mov ax,04c00H
int 21H
code ends
end begin