Abstract: The present invention relates to a data recovery technique for recovering unrecoverable data from a sector having a synchronization field damaged after formatting time or a synchronization mark that has been written improperly. The present invention may try conventional or traditional data recovery techniques first, but if these techniques are ineffective, these techniques can be bypassed in favor of an additional recovery mode. Based upon overall design parameters of a disk drive system and the recording medium format, the disk drive firmware estimates a synchronization mark starting position, analyzes the accuracy of that position and when re-synchronization has not yet occurred, the firmware makes iterative estimates within a window relative to the starting position, and analyzes these subsequent positions for accuracy as well. Once a synchronization mark is located, the data in the sector can be recovered.

Abstract: Inserting operational data onto a magnetic disk allows information to be transferred from a servowriter station to a verifier station. This operational data allows disk specific operational data to follow the disk without separate means for attaching data to each disk. The servowriters, which cannot write information to disks at the data sector frequency, inserts the operational data into selected greycodes in the servo sectors. When the disks are verified, the operational data may be moved from the servo sectors to the data sector in the Z-tracks for more permanent storage.