Browse Prior Art Database

Buffered Standard Output Channel for I/O System

IP.com Disclosure Number: IPCOM000090931D
Original Publication Date: 1969-Aug-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Blevins, PR: AUTHOR

Abstract

The technique is for controlling a number of devices by a controller originally arranged to control a single device. To facilitate programming where only one device is to be controlled by a processor, the system can be arranged such that the processor automatically outputs a program step upon receipt of a ready feedback signal from the device. It then loops until another ready signal is received. Such a system can be expanded to include a number of other devices without altering operation of the systems by providing a device selection bus. This selects the particular device which is to receive the output byte. Following transmission of the byte to the selected device, the buffered channel automatically brings up the ready line.

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Buffered Standard Output Channel for I/O System

The technique is for controlling a number of devices by a controller originally arranged to control a single device. To facilitate programming where only one device is to be controlled by a processor, the system can be arranged such that the processor automatically outputs a program step upon receipt of a ready feedback signal from the device. It then loops until another ready signal is received. Such a system can be expanded to include a number of other devices without altering operation of the systems by providing a device selection bus. This selects the particular device which is to receive the output byte. Following transmission of the byte to the selected device, the buffered channel automatically brings up the ready line. This action enables the processor to execute the next program step which is again selection of a device. To prevent transmission of another byte in the event that the same device is again selected, a device status latch, which is set by the true feedback signal from the device, immediately drops the ready line upon reselection of the device in the event that the device is not ready.

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