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Burst Mode PIO Bus Control Disclosure Number: IPCOM000070329D
Original Publication Date: 1978-Sep-01
Included in the Prior Art Database: 2005-Feb-21

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Related People

Callahan, RW Mitchell, MJ Page, HL [+details]


In some data processing systems, a microprocessor is used to control a programmed input/output (PIO) bus which is used to connect various input/output (I/O) devices to a large-scale data processor. As currently used, the PIO bus is, at best, utilized less than 50% of the time. This is caused by the store and forward operation where data from the large-scale processor must be read and buffered by the microprocessor and then retransmitted to an I/O device. The same is true in the opposite direction. The same data must be transmitted twice in either direction. This store and forward operation also increases the storage requirements of the microprocessor by requiring separate buffers to be dedicated to each I/O device in most cases.