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