Wolfgang H Hausen

RE310697, Oct 26, 1982

Nov 26, 1980

6/210631

Henry K. Chang - San Jose CA
Wolfgang H. Hausen - San Jose CA

International Business Machines Corporation - Armonk NY

G11B 509

360 53

In an apparatus and method for record reorientation following error detection in a data storage subsystem each data track is subdivided into equal time-length recording cells which are sequentially numbered past an index point with the beginning of each field of each record coinciding with an initial cell for the field. Upon detection of a retriable error within a given field, the initial cell for the field is determined and stored, the subsystem is disconnected from an interfacing channel, and reorientation is attempted by advancing a transducer addressing the track past the index point to a location which is a selected distance upstream of the stored cell number. If a selected channel command is then received within a given time interval, the subsystem is reconnected to the channel and reorientation is effected as the transducer enters the field the initial cell of which was stored. If the selected channel command is received late, the subsystem waits one revolution of the track and then reorients without looking for further channel commands.

42098092, Jun 24, 1980

Sep 11, 1978

5/940949

Henry K. Chang - San Jose CA
Wolfgang H. Hausen - San Jose CA

International Business Machines Corporation - Armonk NY

G11B 509

360 53

In an apparatus and method for record reorientation following error detection in a data storage subsystem each data track is subdivided into equal time-length recording cells which are sequentially numbered past an index point with the beginning of each field of each record coinciding with an initial cell for the field. Upon detection of a retriable error within a given field, the initial cell for the field is determined and stored, the subsystem is disconnected from an interfacing channel, and reorientation is attempted by advancing a transducer addressing the track past the index point to a location which is a selected distance upstream of the stored cell number. If a selected channel command is then received within a given time interval, the subsystem is reconnected to the channel and reorientation is effected as the transducer enters the field the initial cell of which was stored. If the selected channel command is received late, the subsystem waits one revolution of the track and then reorients without looking for further channel commands.