The 2065 has both 10-base-2 (BNC/coax) as well a DB15 AUI port. The AUI port can be adapted to 10-base-T (RJ45) with a transceiver.

Jumpers:

JP1 to JP6 control the interupt settings. DON'T mess with these. Leave it on JP2 (interupt 2)

At the back there is a bank of jumpers labelled ABC. All jumpers on AB means the 10-base-2 (BNC/coax) port is used, all jumpers on BC is for the AUI port.

JP7 unknown. Default is off. Leave it alone :)