Jasper Anthony Indelicato

US Patent:

48336793, May 23, 1989

Filed:

Aug 31, 1987

Appl. No.:

7/091482

Inventors:

Robert W. Anderson - Morgan Hill CA
Ralph L. Gee - San Jose CA
Jasper A. Indelicato - Manteca CA
Arvind M. Patel - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1110

US Classification:

371 38

Abstract:

A method and apparatus is disclosed that is selectively conditionable, during read processing, to operate in normal or diagnostic on-the-fly mode or in normal or diagnostic deferred mode to correct errors in encoded uncorrected data in a disk storage device. During deferred mode operation, hardware in the disk storage device receives uncorrected data in real time and generates syndrome bytes which are decoded at the device into error pattern and error location information that is transmitted to a storage director. Circuitry is provided for retaining, if desired, error pattern and location information to facilitate identification of surface defects in the storage disk whether read processing was done on-the-fly or in deferred mode.