The only exception I know of to that would be some GFX cards that have a built-in scandoubler and pass-trhough. My father had one on his A4000, think its a picasso. If you have an amiga w/o the correct (Zorro?) slot, you're SOL with that, too. Though I have been eying up some scandoublers designed for video game systems on Amazon and Ebay, these seem to have both VGA and S-Video adapters, which would be easily adapted to an RGB port, not sure if they auto-switch, though. I'll post a link if I can manage to find one again.