so u need a card with a built-in scandoubler.
there are 2 that come in mind, the best zorro rtg which is the PicassoIV , and the Cybervision64/3D with the optional scanboubler.
-or- get a videoslot AGA scandoubler and get a card that has a scandoubler input, like the Cybervision64 that AmigaZ recommended, or a PiccoloSD64, or a card that has 2 vga connectors on the backplate, see them all here:
http://amigahardware.mariomisic.de/cgi-bin/showcat_en.cgi?CATID=16 edit: you need a scandoubler/flickerfixer to display AGA on a VGA monitor. the RTG then takes this signal, and whenever nescessary it automatically switches between aga/rtg. not all rtg have this feature though, look for 2 vga ports on the backplate...
