Heath/Zenith - ARCNET Board

Network boards were relatively rare for S-100 boards. This card came out before the widespread use of the Internet IP addressing system and the Ethernet networking system were widely accepted.

The card worked well in an environment of up to 255 networked local computers utilizing the Arcnet protocol. ARCNET was developed by the principal development engineer at Datapoint Corporation, John Murphy in 1976 and announced in 1977.  It was the first LAN-based clustering solution, originally developed as an alternative to the larger, more expensive mainframe computer type systems.  It was popular in the early 80's until Ethernet went from coaxial to twisted pair and faster speeds. 

There were numerous switches on the card to configure it.  The whole process of setting up a small office network with these cards required careful reading of the manual and configuration of each board to have a unique ID in the local network of (2-255 computers).

The very detailed manual for this board can be obtained here.
The schematic for the board can be obtained here.