I've just bought a ST-labs USB 2.0 card that has VIA 6202/6212 chip on it,
and I'm trying to get it going on an Ultra 5.

The problem is that it seems that the machine does not see the card at
all. I've got ohci compiled in kernel, but it does not attach. Neither
are there any "not configured" messages for any cards at the pci bus.
And, finally, looking at device tree at the firmware prompt, the card
is not there either. I see the built-in devices under pci@1,1 and
an additional IDE controller under pci@1, and I guess the USB card
should be there, too, but it isn't.

Is there some sort of magic that has to be performed before the card
will work? Or is the card possibly broken, or am I just so out of luck?

The FAQ has something about updating the firmware configuration to
make generic PCI cards going, but the FAQ mentioned only IDE cards.
Is that of any relevance here?