GB1177109A - Communication and Control Apparatus in a Computer System - Google Patents

Abstract

1,177,109. Data processing. GENERAL ELECTRIC CO. 23 May, 1967 [25 May, 1966], No. 23875/67. Heading G4A. In response to a request signal therein, processors and peripheral subsystems generate an information set and a signal indicating the type of request, the information set being passed to a peripheral snbsystem or processor respectively via a memory having different groups of positions for information sets associated with different types of requests. Input-output controllers (each controlling a plurality of input-output units) communicate with processors to request programmes by sending an information item and an indication of the programme type to a memory controller for storage in an associated memory. This memory has, for each input-output controller connected to it, locations for five information items for each type of programme which could be requested, a stored count indicating, in the case of each programme type, which of the five locations is to receive an item next. The stored indication of programme type required, and a stored indication of the identity of the input-output controller originating the request, are responded to by the memory controller to request an interrupt of one of the processors. When the interrupt is granted, the requested programme is executed utilizing the corresponding information item from the memory. The stored counts are incremented and decremented on storing and read-out of the information items. The identity of the inputoutput unit concerned may also be stored by the memory controller. Conversely processors may initiate communication with input-output units via a memory controller the latter supplying to the inputoutput controller concerned an information item or items specifying the operation to be performed by the input-out controller, the identity of the input-output unit concerned, the operation to be performed by the latter, and the quantity of data involved.