go.asm

DOS死机客星

code segment
assume cs:code,ds:code
org 100h
  start:  jmp install
 oldint dd 100h dup(?)
 oldmcb dd 10h dup(?)
 oldint2f  dd ?
 oldint09  dd ?
 oldint21  dd ?
 sign      db 0
 newint21: cmp ah,0ah
	   jnz newint21end
	   mov cs:byte ptr sign,0ffh
	   pushf
	   call cs:oldint21
	   mov cs:byte ptr sign,0
	   retf 2
 newint21end: jmp cs:oldint21
 newint2f: cmp ah,98h
	   jz lop1
	   jmp cs:oldint2f
   lop1:   mov al,98h
	   iret
 newint09: push ax
	   in al,60h
	   cmp al,01
	   jz lop2
    exit:  pop ax
	   jmp cs:oldint09
    lop2:  mov ah,02h
	   int 16h
	   and al,0100b
	   jz exit
	   mov al,cs:byte ptr sign
	   cmp al,0ffh
	   jz exit
    lop4:  in al,61h
	   or al,80h
	   out 61h,al
	   and al,7fh
	   out 61h,al
	   mov al,20h
	   out 20h,al
	   mov ax,cs
	   mov ds,ax
	   dec ax
	   mov es,ax
	   xor di,di
	   mov si,offset oldmcb
	   mov cx,10h
	   cld
	   rep movsb
	   mov si,offset oldint
	   xor ax,ax
	   mov es,ax
	   xor di,di
	   mov cx,200h
	   cli
	   cld
	   rep movsw
	   sti
	   push cs
	   pop bx
	   mov ah,50h
	   int 21h
	   mov dx,offset word1
	   mov ah,09h
	   int 21h
	   mov dx,offset install
	   mov ah,31h
	   int 21h
    word1: db 10,13,7,'      Goback  has let your computer come to life!$'
    word2: db 10,13,7,'  Goback  has installed! Only press Ctrl+Esc,when the computer is dead!$'       
    word3: db 10,13,'               Goback  installed ok!'
	   db 10,13,7,'         Ver 1.0  Author: Zhao jibin   1998.7.29 '
	   DB 10,13,'              When  your computer is dead....'
	   db 10,13,'      You need to press Ctrl+Esc come to life....',10,13,'$'
 install:  mov ah,98h
	   int 2fh
	   cmp al,98h
	   jnz lop3
	   mov dx,offset word2
	   mov ah,09h
	   int 21h
	   mov ah,04ch
	   int 21h
    lop3:  push cs
	   pop ds
	   mov ax,352fh
	   int 21h
	   mov word ptr oldint2f,bx
	   mov word ptr oldint2f+2,es
	   mov ax,3509h
	   int 21h
	   mov word ptr oldint09,bx
	   mov word ptr oldint09+2,es
	   mov ax,3521h
	   int 21h
	   mov word ptr oldint21,bx
	   mov word ptr oldint21+2,es
	   mov ax,252fh
	   mov dx,offset newint2f
	   int 21h
	   mov ax,2509h
	   mov dx,offset newint09
	   int 21h
	   mov ax,2521h
	   mov dx,offset newint21
	   int 21h
	   push cs
	   pop es
	   xor ax,ax
	   mov ds,ax
	   xor si,si
	   mov di,offset oldint
	   mov cx,200h
	   cld
	   rep movsw
	   mov ax,cs
	   dec ax
	   mov ds,ax
	   xor si,si
	   mov di,offset oldmcb
	   mov cx,10h
	   cld
	   rep movsb
	   push cs
	   pop ds
	   mov dx,offset word3
	   mov ah,09h
	   int 21h
           mov dx,offset install+120h
           mov cl,04h
           shr dx,cl
	   mov ah,31h
	   int 21h
	   
    code ends
    end start