Browse Prior Art Database

Enhanced IO Subsystem Using a Device Engine

IP.com Disclosure Number: IPCOM000087864D
Original Publication Date: 1977-Mar-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Bantz, DF: AUTHOR [+3]

Abstract

The subject system provides for the functional enhancement of a computer I/O subsystem with minimal impact on operational software in the host computer. This is accomplished, as shown in the figure, by a method of adding to a host 10 a satellite processor or device engine 12, which appears to be a disk drive to an existing disk control unit 14. The device engine 12 is attached to the channel port of the control unit 14 so that it has access to the other real disk drives 16 attached to that control unit.

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Enhanced IO Subsystem Using a Device Engine

The subject system provides for the functional enhancement of a computer I/O subsystem with minimal impact on operational software in the host computer. This is accomplished, as shown in the figure, by a method of adding to a host 10 a satellite processor or device engine 12, which appears to be a disk drive to an existing disk control unit 14. The device engine 12 is attached to the channel port of the control unit 14 so that it has access to the other real disk drives 16 attached to that control unit.

The host software for communicating with the device engine 12 is the software for writing and reading a magnetic disk. The engine can thus be added to a large system without modifying existing software.

The figure shows the host computer 10 and its memory 18, which contains two channel programs 20 and 22. Both of these channel programs operate the same disk control unit. Several of the control unit disk interfaces are shown attached to an adapter 24, which generates the protocol required in order to make the adapter appear as disk drives to the disk control unit 14. The adapter 24 is also attached to the I/O channel 26 of the device engine 12, a processor (e.g., a minicomputer) which will appear as disk drives to the host computer. With the arrangement shown, data transfers and control signals destined to real disks on the disk control unit 14 are unaffected by the presence of the device engine 12.

The device engine 12 i...