Seagate Technology Incorporated

William C Little

Monty Aaron Forehand

Krishna Rameshwara Malakapalli

Mark A Gaertner

Dallas W Meyer

Paul William Burnett

Mukund Channagiri Rao

Matthew Chad Burton

Ke Du

Brian W Sudman

Joseph S Stoutenburgh

Todd Phillip Fracek

Donald B Douglas

Florence F Kung

Charles E Skeldon

Jimmie R Shaver, Jr

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.

Error recovery using alternate headers in a disc drive

An apparatus and method for optimizing detection thresholds used to identify addresses of tracks in a disc drive having a head and a disc upon which a plurality of tracks are defined, the tracks including track address fields in which track address information is stored. A comparator is provided which generates track address sequence signals in response to a corresponding plurality of readback signals obtained as the head is maintained in a fixed relationship to a selected track. A demodulator identifies erroneous track address sequence signals therefrom and increments a count in an accumulator for each detected, erroneous signal. A detection threshold circuit sequentially provides the comparator with a set of detection thresholds from a population of detection thresholds, each of which are used in turn by the comparator. An optimal set of thresholds is thereby selected for use by the disc drive in accordance with the relative number of erroneous track address sequence signals accumulated for each of the detection thresholds from the population.

Optimizing track address detection in a disc drive

A magnetic disc storage system includes a magnetic storage disc and a transducing head. During periods of inactivity the transducing head is dithered whereby the head is moved to tracks on the disc according to a number of criteria. The criteria includes wear reduction, power reduction, avoidance of textured zones, head cycling, increased fly height and clearing of debris carried on the head.

Head positioning in storage system during periods of inactivity

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Edmond, OK, United States of America

William C Little