I think I have better understanding of why you need the AUI-RJ45 transceiver after looking at the a2065 card more closely. Am I correct you need this as an adapter for the standard RJ-45 female connector? It looks like the a2065 has a BNC type connector.
Yeah the card was designed for
http://en.wikipedia.org/wiki/10BASE5 and
http://en.wikipedia.org/wiki/10BASE2 With 10BASE5 you had a cable from the network cable to your computer (think of it like a T piece in 10BASE2)
http://en.wikipedia.org/wiki/Attachment_Unit_Interface "AUI connectors became rare beginning in the early 1990s when computers and hubs began to incorporate the MAU, particularly as the
10BASE-T standard became more common and use of
10BASE-5 (thicknet) and
10BASE-2 (thinnet) declined. "
