Interface Message Processors for the ARPA Computer Network
A 1975 technical report by Frank E. Heart and Bolt Beranek and Newman Inc. of Cambridge, Massachusetts, issued through the Defense Technical Information Center, on interface message processors for the ARPA computer network. The first picture is a labelled monitoring diagram of a pluribus subsystem with nodes, timers and a consensus block, and the second is a bare wiring diagram of many boxes linked by crossing lines to a few outputs, both useful to a designer for schematic layout, flowchart style and network-diagram linework.
