Walter Allen

US Patent:

7193798, Mar 20, 2007

Filed:

Jan 12, 2005

Appl. No.:

11/034133

Inventors:

James Byrd - Berthoud CO, US
Walter Allen - Wellington CO, US

Assignee:

Agere Systems, Inc. - Allentown PA

International Classification:

G11B 5/09

US Classification:

360 39

Abstract:

One or more bits are added to the embedded repeatable runout correction (ERRC) bit pattern of a servo field so that errors in ERRC bit patterns can be detected and in certain cases corrected. If four bits are added, a single bit error in an ERRC bit pattern can be detected and corrected. If five bits are added, two bit errors in the ERRC bit pattern can be detected. In accordance with the preferred embodiment, the invention uses a single encode table and a single decode table to encode the ERRC pattern to be written to the disk and to decode the ERRC pattern read back from the disk.

US Patent:

20070053093, Mar 8, 2007

Filed:

May 19, 2006

Appl. No.:

11/419279

Inventors:

Walter Allen - Longmont CO, US
Robert Reid - Superior CO, US

International Classification:

G11B 5/09

US Classification:

360048000

Abstract:

A method and apparatus for storing a disk drive media defect table or list. Defect table entries for a subject disk track are stored on the subject track and retrieved for determining defective sectors only when the subject track is accessed for a data read or write operation.