Actually, there was a card called the "Golden Gate II" which mapped the ISA cards into the Zorro memory space. It's a bit confusing because the was also a 3rd-party bridgeboard called the Goldengate. (people must really like that SF bridge!)
Anyway, the GGII did allow ISA cards to be used directly by the Amiga side. If i recall, there was support for some net cards, sound cards, and serial/parallel cards. No VGA cards though.
Going waaaay back, there was a thing for the 1000 called "Bill's Board" that gave it Zorro & ISA slots. I remember seeing one of those demoed at a user group meeting. Talk about a monster hack....
