So with Andy at Ultimarc's help, I finally got my ArcadeVGA 3000 all set up and working with my standard 15Khz arcade monitor. The recommended setup is to allow MAME to set the appropriate resolution for the monitor so you get perfect graphical emulation for the chosen game. This works excellently well for the most part, except when running games with an unsupported resolution, or more commonly, running a vertical game on a horizontal monitor. What's a good solution for this problem? Set custom settings for every game that is vertical or has an unusual resolution? Is there a good heuristic or best practice for achieving good results, and are there tools available to help accomplish this?