Computer apparatus which employs a plurality of processing units, a memory unit, and a communication unit, each of the units including a data transfer bus. A bus coupler is provided between each pair of units of differing type to form a distributed data communications network. An addressable, passive...http://www.google.de/patents/US4130865?utm_source=gb-gplus-sharePatent US4130865 - Multiprocessor computer apparatus employing distributed communications paths and a passive task register
