;--------------------------------------------------------------------
; Copyright (C) 2001 Jimmy Thrasher
;
;    This program is free software; you can redistribute it and/or modify
;    it under the terms of the GNU General Public License as published by
;    the Free Software Foundation; either version 2 of the License, or
;    (at your option) any later version.
;
;    This program is distributed in the hope that it will be useful,
;    but WITHOUT ANY WARRANTY; without even the implied warranty of
;    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;    GNU General Public License for more details.
;
;    You should have received a copy of the GNU General Public License
;    along with this program; if not, write to the Free Software
;    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
;--------------------------------------------------------------------
; Compile with: nasm -o antiYomip.com
; Does very little error-checking.  Requires a file called 'file.pdb'
; to be in the current directory, and generates 'FILE.GZ'
;--------------------------------------------------------------------
%define msdos 0x21
%define quit 0x20

%macro open_file 0
   mov ah, 0x3D
   mov al, 0x12
   int msdos
%endmacro

%macro open_new_file 0
   mov ah, 0x3C
   mov cx, 0
   int msdos
%endmacro

%macro write_to_file 0
   mov ah, 0x40
   int msdos
%endmacro

;--------------------------------------------------------------------
   org 0x100
   section .text
start:
   mov dx, infile
   open_file
   jc quitty
   mov [infile], ax

   mov bx, [infile]
   mov cx, 0108h ; must skip first 0x108 bytes
   mov dx, buffer
   call read_to_buffer

   mov dx, outfile
   open_new_file
   mov [outfile], ax

loopy:
   mov bx, [infile]
   mov cx, 0400h ; 1024 bytes
   mov dx, buffer
   call read_to_buffer
   jc quitty

   cmp ax, 0
   jz quitty

   mov cx, ax
   mov bx, [outfile]
   ;mov dx, buffer
   write_to_file

   jmp loopy

quitty:
   mov ax, 0x4C00
   int msdos

read_to_buffer: ; in: BX->filehandle, DS:DX->buffer, CX->amount to read, out: contents in buffer, AX->amount read
   mov ah, 0x3F
   int msdos
   ret

   section .data
infile:        db 'file.pdb',0
outfile:       db 'file.gz',0
   section .bss
buffer:        resb 1024