1. 程式人生 > >用7ch中斷例程完成jmp near ptr s指令的功能,用bx向中斷例程傳送轉移位移。

用7ch中斷例程完成jmp near ptr s指令的功能,用bx向中斷例程傳送轉移位移。

應用舉例:在螢幕的第12行,顯示data段中以0結尾的字串。

assume cs:code

data segment
      db 'conversation',0
data ends

code segment

start:
               mov ax, data
               mov ds, ax
               mov si, 0
               mov ax, 0b800h
               mov es, ax
               mov di, 12*160

s:
               cmp
byte ptr [si], 0 je ok mov al, [si] mov es:[di], al inc si add di, 2 mov bx, offset s-offset ok int 7ch ok: mov ax, 4c00h int 21h code ends end start

安裝程式

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-offsetdo0 cld rep movsb mov ax,0 mov es,ax mov word ptr es:[7ch*4],200h mov word ptr es:
[7ch*4+2],0 mov ax,4c00h int 21h do0: push bp mov bp,sp add [bp+2],bx pop bp iret mov ax,4c00h int 21h do0end: nop code ends end start