If I recall correctly, as you've noted it was a WaveLAN / Orinoco silver card ('HERMES' chipset), connected via PCMCIA to a SBC based around an AMD ELAN SC400 - 33AC 486-like CPU. It had something like a couple megs of RAM and maybe 512K of FLASH. I don't know what OS it ran, if anything 'off the shelf' Why do you ask?
One of the early Apple Airports ran NetBSD, I believe supported by Wasabi Systems originally of NYC, then Norfolk VA. Not sure if it was the first.
I still have a pre-wifi 13" long ISA WaveLan card that is in the 915mhz ISM band sitting on a shelf.
-- Ethan O'Toole