If we can't find the docs try the BSD 4.1/4.2 docs, A/UX is essentially UniPlus which was vanilla AT&T System V with Berkeley 4.1 networking added, the Apple team upgraded things to BSD 4.2 networking by A/UX 3.0

I found some source code for UniPlus v1.5 for the Apple LISA.

https://github.com/arcanebyte/uniplus

The 3Com Ethernet driver looks very similar to the one from the 4.2 BSD distribution.

https://github.com/arcanebyte/uniplus/blob/master/v1.5/sys/i...

So I'll need to see if I can emulate how drivers are linked in and probed.

That's much older than A/UX, likely v7 or System III based with BSD4.1 networking

(We did both V7 and SIII ports to the Lisa)

Any luck looking for those A/UX materials? I have no way to contact you outside HN. Please drop me an email or a tweet.

Cool project! Do you have any plans to make these cards available to hobbyists when you have the drivers worked out?

I've always thought it would be amazing if somebody developed an ethernet interface for the 100-series powerbooks. It would certainly make it easier to transfer files to and from my trusty Powerbook 180.

Yeah, the plan is to open-source everything including PCB designs, drivers and CPLD firmware.

I'm not sure if it would be possible to redesign the card to fit in a Powerbook 100-series though. The Powerbook 180 appears to have a modem expansion slot but that doesn't give access to the processor bus AFAICS.