Extended peripheral bus with bidirectional transmission

摘要

A keyboard bus is provided in a PC for connecting a peripheral such as a keyboard to a central unit, serially through external modules coupled to the bus enabling communication with the central unit by any of the external modules or the keyboard independently of other. The external modules are coupled serially to each other with a peripheral device, such as a keyboard, disposed most remotely from the central unit. The modules are serially connected in an open chain to the central processor for communication bidirectionally by an address signal to the intended respective module and an attention acknowledgment signal back to the central processor indicating a readiness for data reception.