Performance Assist for Checksum DASD
Original Publication Date: 1989-Dec-01
Included in the Prior Art Database: 2005-Jan-29
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.