If you want a smaller screen in full screen mode, use a non-stretching 2X filter in your GPU plugin with a resolution greater than 800x600 or a 3X unstretched filter with a resolution greater than 1024x768. The resolutions you use vary by game, and the playing screen size will be smaller the higher the resolution you use. This is assuming you are using one of Pete's/PEOPS plugins with filters. I love the HQ 2X unstretched and HQ 3X Unstretched filters personally as you generally dont need any AA on when you use them.