王爽汇编语言第二版学习笔记之实验13(1)

程序:
assume cs:code
data segment
db "welcome to masm!",0
data ends

code segment
start:
mov dh,10
mov dl,10
mov cl,2
mov ax,data
mov ds,ax
mov si,0
int 7ch
mov ax,4c00h
int 21h
code ends
end start

7C中断例程：
assume cs:code
code segment
start:
mov ax,cs
mov ds,ax
mov si,offset do0

mov ax,0
mov es,ax
mov di,200h

mov cx,offset do0end-offset do0
cld
rep movsb

mov ax,0
mov ds,ax
mov word ptr ds:[7ch*4],200H
mov word ptr ds:[7ch*4+2],0H

mov ax,4c00h
int 21h

do0:
mov ax,0
mov bl,cl

s:
mov ah,2
mov bh,0
int 10h

mov ah,9
mov byte ptr al,ds:[si]
cmp byte ptr al,0
je ok
mov cx,1
int 10h
inc dl
inc si
jmp short s
ok:
iret

do0end:
nop

code ends
end start