The IBM Async card has logic to do this (you have to
jumper the 2 pin
header in the middle of the card). Some M$ bus mouse cards have a similar
feature. Those are all I've seen, but Eric has reported seeing 8 bit VGA
cards that can do this. Maybe others as well.
I've got an Everex 1200 bps modem, a Video Seven VEGA VGA, and a no-name
NE1000 compatibile ethernet card that claim slot 8 compatibility in their
docs. Most other 8 bit cards I have have no docs.
Eric