Multiport I/O cards: for which cards is driver source available?

[Michael Haberler]

As far as I can tell, most intelligent cards come with object files for
usual operating Systems. 

I'm looking for an intelligent card which comes with example drivers in source,
or at least a decent Programmer's reference manual. Reason: writing drivers
for non-standard operating environments line NOS KA9Q.

Is there such an animal?

thank,
-michael