Patent ID: 7057836

Claim:
A disk drive comprising: a moveable head; a disk having a circumferential track, the circumferential track having a plurality of servo wedges utilized in track following, the plurality of servo wedges each including an extended servo header, the plurality of servo wedges being spaced sequentially around a circumference of the circumferential track; and a servo controller to perform track following with the moveable head, the servo controller to compensate for servo wedge timing errors due to eccentricity associated with the servo wedges of the circumferential track by implementing; a first mode in which the servo controller locks to the extended servo header of a servo wedge and performs servo wedge timing error learning to characterize servo wedge timing errors; and a second mode to adapt servo control signals of the servo controller based on the characterized servo wedge timing errors of the first mode in order to compensate for the eccentricity associated with the servo wedges.