Abstract: One embodiment of the present invention is an apparatus to provide a measure of disk drive head velocity in a disk drive wherein movement is produced by a disk drive motion mechanism that includes a coil, which apparatus includes: (a) a controller that outputs one or more digital signals that are applied as input to a first component, and in response, the first component outputs a reference voltage; (b) a second component, responsive to voltage output across the coil and the reference voltage, outputs a measure of a difference between the coil voltage and the reference voltage; and (c) a third component, responsive to the measure of the difference, outputs a first value if the coil voltage is greater than the reference voltage and a second value if the coil voltage is less than the reference voltage, which third component output is applied as input to the controller; wherein the controller executes a search algorithm that varies the one or more digital signals while observing changes in the third component ou

Abstract: One embodiment of the present invention is a method for writing data on a number of sectors of a track of a disk drive that includes: (a) sending a signal to write data on a first sector of the track; (b) receiving a write data default; (c) sending a signal to write data on another sector of the track after skipping a predetermined number of sectors; (d) waiting for the first sector to be in position again; and (e) sending a signal to retry to write data on the first sector if a predetermined number of retries to write data on the track has not been exceeded.

Abstract: One embodiment of the present invention is an apparatus to provide a measure of disk drive head velocity in a disk drive wherein movement is produced by a disk drive motion mechanism that includes a coil, which apparatus includes: (a) a controller that outputs one or more digital signals that are applied as input to a first component, and in response, the first component outputs a reference voltage; (b) a second component, responsive to voltage output across the coil and the reference voltage, outputs a measure of a difference between the coil voltage and the reference voltage; and (c) a third component, responsive to the measure of the difference, outputs a first value if the coil voltage is greater than the reference voltage and a second value if the coil voltage is less than the reference voltage, which third component output is applied as input to the controller; wherein the controller executes a search algorithm that varies the one or more digital signals while observing changes in the third component ou

Abstract: One embodiment of the present invention is a small form factor disk drive for use in an appliance, which disk drive includes: (a) a connector side, a removal side, and a lateral side; and (b) a gripping mechanism affixed to a lateral side of the disk drive; wherein a portion of the gripping mechanism extends beyond the removal side.

Abstract: A method for applying an adaptive feed-forward waveform correction to a primary servo loop compensation signal in a rotating data storage apparatus. A position error signal is used to determine a fixed feed-forward correction upon initialization or other predetermined conditions. An adaptive feed-forward waveform correction is periodically determined by adding a scaled version of the position error signal to the stored adaptive feed-forward value, and then processing the resulting sum through a frequency selective filter. The stored adaptive feed-forward correction is then updated with this new result. Simultaneously, the updated adaptive feed-forward correction is combined with the fixed feed-forward correction and the position error signal to generate a primary servo loop compensation signal for controlling the read/write head of the data storage apparatus.

Abstract: A disk drive employing a voice coil actuator to position a read/write head over a magnetic disk retracts the read/write head from the magnetic disk surface and passes an audio frequency alternating current through the voice coil to produce a corresponding movement in the read/write head support structure which generates an audible tone indicating the disk drive status. The alternating current waveform has a positive phase and a negative phase, with the read/write head moving toward the disk in response to one phase of the current and the read/write head moving away from the disk in response to the other phase. Audible tones of different frequencies are produced by varying the frequency of the alternating current waveform. In this fashion the disk drive generates a predetermined sequence of tones separated by silent pauses which identifies a particular disk drive status condition.