Abstract: A local area data distribution system includes a plurality of data processing stations connected to a common bus. Individual data processing stations contend with each other for access to the bus while the bus is held at a predetermined and controlled but overridable logic state by applying their priority code bit by bit to the bus and comparing the logic state of the bus with the bit they are applying thereto. A biasing arrangement holds the bus at the predetermined and controlled logic state during the contention interval at a signal level that may be easily overridden by an output of any one of the individual data processing stations.

Abstract: In a local data distribution network configuration a plurality of bidirectional data distribution busses are each connected to a bus master control circuit at a terminal end of the bus. Connected to each of the data distribution busses are a plurality of passive outlets to which intelligent connectors or stations may be connected. Each station has a unique address and is utilized for individually coupling data processing devices to the bus. Grouped pluralities of the bus master control circuits are included within a bus termination hub facility. Data from any of the bus master control circuits may be transferred by the bus termination hub via a data trunk as part of a star type configuration, to a central switching circuit such as a virtual circuit switch. Direction of data flow on each of the bidirectional busses and periodic temporary synchronization of the stations is controlled in response to signals transmitted to the bus by the bus master control circuitry associated with that bus.