Abstract: A disk drive is disclosed comprising a head actuated over a disk surface, the head comprising a fly height actuator for controlling a fly height of the head, and a ramp for parking the head. A ramp procedure is executed by applying a control signal to the fly height actuator to decrease the fly height and receiving a corresponding fly height signal, and detecting whether the head is on the ramp in response to the fly height signal.

Abstract: A disk drive is disclosed comprising a head actuated over a disk, and a spindle motor operable to rotate the disk. A bootstrap spiral track is written to the disk, wherein the bootstrap spiral track comprises a high frequency signal interrupted by sync marks. A first sync mark is written while writing a first part of the bootstrap spiral track, and a second sync mark is written while writing a second part of the bootstrap spiral track. A switch between writing the first sync mark and the second sync mark is made in response to a spindle BEMF voltage, thereby generating a sync mark seam in the bootstrap spiral track.

Abstract: A disk drive is disclosed comprising a head actuated over a disk, wherein a bootstrap spiral track is written on the disk. While servoing on the bootstrap spiral track at least one circular reference track is written on the disk. A velocity profile is adjusted in response to the circular reference track, and a plurality of spiral tracks are written to the disk in response to the velocity profile.