High-speed multiplexing of keyboard data inputs

Abstract

A high-speed multiplexing system of keyboard data inputs in which keyboard entered data is sequentially and automatically sampled by the multiplexing system for input to a computer. More specifically, a system is disclosed whereby a plurality of data inputs from a plurality of keyboards are applied to a multiplexer having a single output connected to a computer. A sequencer is provided which sequentially and automatically controls the multiplexer to sample each keyboard input in accordance with a predetermined sampling sequence. Whenever keyboard entered data appears on input lines to the multiplexer, the system inputs the keyboard data to the computer during a brief time interval in which the multiplexer remains at the particular keyboard address or port. Thus, a high-speed sampling circuit is provided whereby the only operator action required is data entry through a keyboard. Priority or interrupt systems are not required, and the multiplexer merely samples each keyboard output continually at high speed according to a predetermined sequence.