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Browse Prior Art Database

Performance Assist for Checksum DASD

IP.com Disclosure Number: IPCOM000037222D
Original Publication Date: 1989-Dec-01
Included in the Prior Art Database: 2005-Jan-29

Publishing Venue

IBM

Related People

Authors:
Tetzlaff, WH [+details]

Abstract

This describes a way to assist a CPU-intensive aspect of writing "checksum" DASD blocks. An example of "checksum" DASD is the IBM System/38 usage to provide a form of duplexing of DASD. This disclosure places the two Exclusive OR operations in the I/O subsystem in order to reduce the CPU time needed to prepare the checksum record and to eliminate cache damage.