Fault tolerant digital data processor with improved communications monitoring

Abstract From the Canadian patent

A fault-tolerant digital data processing system comprises at least a first peripheral controller communicating with at least one peripheral device over a peripheral device bus having first and second input/output buses, each carrying data address, control, and timing signals The first peripheral controller includes a first device interface element for applying duplicate information signals synchronously and simultaneously to the first and second input/output buses for transfer to the peripheral device. The first device interface element also receives, in the absence of fault duplicative information signals synchronously and simultaneously from the first and second input/output buses. A …