PCL11 Communications System
From Computer History Wiki
The PCL11 Communications System was a communication link, effectively a local area network, which could connect together up to 16 PDP-11s. The physical network was a time-division bus, with one of the interfaces serving as a 'TDM Bus Master', setting the timing (another could be designated as the 'Secondary Master', in case the primary was powered down or dis-connected).
There was only one network interface for it, the UNIBUS PCL11-B interface unit.
