int 7eh
本帖最后由 loop 于 2011-5-17 12:42 编辑小甲鱼老师：在int7eh
7eh实现loop s指令的功能cx,bx存放位移在屏幕中央显示80个！assume cs:code
code segment
mov ax,0b800h
mov es,ax
mov di,160*2
mov bx,offset s - offset se
mov cx,80
s:mov byte ptr es:,'!'
add di,2
int 7eh
se: nop
mov ax,4c00h
int 21h
code ends
end start
assume cs:code
code segment
start:
;7eh安装程序
mov ax,cs
mov ds,ax
mov si,offset ip
mov ax,0
mov es,ax
mov di,200h
mov cx,offset ipend - offset ip
cld
rep movsb
;设置中断向量表
mov ax,0
mov es,ax
mov word ptr es:,200h
mov word ptr es:,0
mov ax,4c00h
int 21h
;ip
ip:
push bp
mov bp,sp
dec cx
jcxz ipret
add ,bx
ipret: pop bp
iret
ipend: nop
code ends
end start在调用中， push bp
mov bp,sp
dec cx
jcxz ipret
add ,bx是 push bp 80次吗？
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