The dual-port Ethernet board is a Farallon EtherWave. It was their attempt to have the cabling benefits of 10Base-T with the bus topology of their older PhoneNet products.

They actually had a pretty full product line which included NuBus and LC network cards, a PCMCIA card (3C589-based), ISA card (for PC), AAUI adapter, a serial-based adapter (Mac/PB adapter) and a PhoneNet "bridge" for AppleTalk printers.