Abstract: A method of allocating transmission time for a plurality of I/O devices (14) connected to a transmission line (12) comprising the steps of causing each device to listen constantly to determine if the line is being used and to only initiate a transmission after waiting a mandatory device delay period (31) and a reply slot period and thereafter to select a random number from 1 to N, with N being the number of bid slots following the mandatory time delay period and the reply slot period, and to begin transmitting only during the bid slot corresponding to the random number selected. Each receiving device is required to answer a transmission during the reply slot period to allow the transmitting device to ascertain that the transmission was received.

Abstract: The digital computer system herein described is a customized group of programmable multiprocessors, multiplex channels, control modules, and peripheral devices. Controlling the operation of a wide variety of data terminals, this system can be an independent digital computer system or a versatile extension of a larger computer system. Selected software, which forms a part of this system, determines the characteristics of the system for any given application. When attached to a host computer, this system can be a local and remote terminal controller, a local and remote external device controller, a front-end communications processor, or any combination of these things. Essentially, this system incorporates standard minicomputer hardware in a novel configuration that enables it to rival or enhance the performance of much larger computer systems.