Donald E Douglas

US Patent:

62055690, Mar 20, 2001

Filed:

Nov 18, 1997

Appl. No.:

8/976208

Inventors:

Monty A. Forehand - Yukon OK
Paul W. Burnett - Oklahoma City OK
Donald B. Douglas - Oklahoma City OK
Charles E. Skeldon - Clearwater MN
Jimmie R. Shaver - Yukon OK
William C. Little - Edmond OK
Florence F. Kung - Yukon OK
Krishna R. Malakapalli - Burnsville MN

Assignee:

Seagate Technology LLC - Scotts Valley CA

International Classification:

G11C 2900

US Classification:

714763

Abstract:

An apparatus and method are disclosed for recovering from a header error condition in a disc drive of the type having a rotatable disc having a plurality of concentric tracks with data fields for the storage and retrieval of data and header fields providing logical address information for the data fields. The header fields include read and write header fields which are used during read and write operations, respectively, to align read and write elements of the head with the data fields. When the disc drive unsuccessfully decodes the logical address information from a selected header field associated with a selected data block, an alternate header error recovery routine is performed wherein attempts are made to decode the logical address information from the alternate header field associated with the selected data block. Radial offsets can further be applied to the head to enhance the decoding of the logical address information from the alternate header field.