@6508.ADF PDIuC508 Microchannel ARCNET Interface Adapter
Based on content by William R. Walsh (original HERE).
Pure Data Arcnet Adapter PDIµC508
U1 Pure Data 2300000000NC (NCR 0380880 ?)
U16 Pure Data 2210000900NC (NCR 0380847 ?)
U17 Boot ROM socket ?
U31 Matra MHS HM3-6116-5
Lots of 74xx series chips are on this adapter.
The yellow circle is a small electrolytic cap. The red and green items are activity LEDs.
Potted parts - a collection of stuff, mostly small ICs under black potting compound.
Not much to say about this adapter. No idea what drivers for what operating systems exist. What little information I have found is here. It seems like versions of this card were made for MANY different computer busses.