Patent US 4,667,192

The present invention discloses a second level bus arbitration method and apparatus for use with a distributed computer network. The invention alleviates any simultaneous access possibility by requiring any computing element which claims access to the bus to first send a pseudo-random sequence over a common line using open collector logic. A computing element can access the bus if the sequence appearing on the common line is the sequence it transmitted. The invented arbitration system does not require central control or centralized clocking.