{$apptype console}
program box1;  uses windows, DirectX;

var
    dirdraw    : IDIRECTDRAW;
    DSurface   : IDIRECTDRAWSURFACE;
    DDsd       : DDSURFACEDESC;
    Rect       : TRect;
    dwThreadId, dwThreadId2 : DWORD;

    SCR        : pointer;

procedure Thread(val:integer);stdcall;
begin
  repeat
    PInteger(integer(SCR)+ random(1024*600)*4 )^ := Random(-1);
  until false;
end;


begin
    DirectDrawCreate (nil,DirDraw,nil);
    DirDraw.SetCooperativeLevel(GetForegroundWindow(),
                                DDSCL_EXCLUSIVE or DDSCL_FULLSCREEN);
    (* dirdraw.SetDisplayMode (640, 480, 16); *)
    ddsd.dwSize         := sizeof(ddsd);
    ddsd.dwFlags        := DDSD_CAPS or DDSD_BACKBUFFERCOUNT;
    ddsd.ddsCaps.dwCaps := DDSCAPS_PRIMARYSURFACE or DDSCAPS_FLIP or DDSCAPS_COMPLEX;

    ddsd.dwBackBufferCount := 1;
    DirDraw.CreateSurface(ddsd, dsurface, nil);

    dsurface.Lock(@Rect,ddsd,{DDLOCK_WRITEONLY}0,0);
    dsurface.Unlock(ddsd.lpSurface);
    SCR := ddsd.lpSurface;


    CreateThread(nil,0,@Thread,nil,0,dwThreadId);

    readln;

end.