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Intelligent Terminal Controller System Attachment to a General Purpose Computer Channel

IP.com Disclosure Number: IPCOM000087131D
Original Publication Date: 1976-Dec-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Opdahl, R: AUTHOR [+3]

Abstract

The I/O Interface of a general purpose computer channel may be viewed as a set of primitives which may be combined in various linear combinations to convey the higher levels of control information required by distributed intelligence systems.

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Intelligent Terminal Controller System Attachment to a General Purpose Computer Channel

The I/O Interface of a general purpose computer channel may be viewed as a set of primitives which may be combined in various linear combinations to convey the higher levels of control information required by distributed intelligence systems.

Input/output (I/O) operations in a general-purpose computer, such as an IBM System 370, are performed by channels, control units, and I/O devices operating under control of the I/O supervisor (IOS) program of the operating system. Logically, the channel is an independent entity that executes a program consisting of commands. The central processing unit (CPU) program starts channel operation by specifying the beginning of the channel program and the device to be used. I/O devices perform I/O operations under control of control units which attach to the CPU via channels. The commands specify the direction of data transfer, the data source or destination in main storage, and all auxiliary functions associated with data transfer. When the channel program ends, the CPU program is interrupted, and pertinent status information is made available. The totality of commands, status information, their protocol and conventions is generally referred to as the I/O Interface. This interface was originally designed for local I/O devices, such as card, storage, and process control devices, and significant architectural changes will impact all existing syst...