Abstract: One illustrative embodiment of the present invention pertains to a device. The device is configured to evaluate a Gray code value and to provide compensation for error in the Gray code value. Another illustrative embodiment of the present invention pertains to a method. The method includes comparing Gray code information with servo information. The method also includes evaluating error in the Gray code information based on the comparison between the Gray code information with servo information. Another illustrative embodiment of the present invention pertains to a data storage system. The data storage system includes a data storage medium, a head, and a controller. The head is controllably positionable relative to the data storage medium. The controller includes a means for sensing position information from the head. The controller also includes a means for compensating for error in the position information, to position the head relative to the data storage medium.

Abstract: A method of calibrating an actuator controller is discussed. The method includes using an open loop seek operation and compensating for a low frequency response to reduce the velocity at the end of the open loop seek operation.

Abstract: Various embodiments are generally directed to moving a control object using a sine-based trajectory profile with an initial non-zero velocity.

Abstract: A method of calibrating an actuator controller is discussed. The method includes using an open loop seek operation and compensating for a low frequency response to reduce the velocity at the end of the open loop seek operation.

Abstract: Various embodiments are generally directed to moving a control object using a sine-based trajectory profile with an initial non-zero velocity.

Abstract: Using a “reference” sensor, a reference position is detected in a frame of reference that is moving along a predetermined path relative to the reference sensor. The reference position is used to derive a position-dependent indicator of a position-dependent “longitudinal” offset component (i.e. along the path). An output from the target sensor is monitored using a “target window” that is partially based on the position-dependent indicator.

Abstract: An apparatus and method for selecting physical cylinders (cylinders accessible for read/write operations) in a disc drive is provided. The disc drive includes at least one rotatable disc. The disc drive also includes a first head, which is positionable adjacent a first disc surface, and a second head, which is positionable adjacent a second disc surface. The first disc surface has a first plurality of greycode tracks and the second disc surface has a second plurality of greycode tracks. Each greycode track of the second plurality of greycode tracks corresponds to a different greycode track of the first plurality of greycode tracks, thereby forming a plurality of greycode cylinders, with each greycode cylinder of the plurality of greycode cylinders including a pair of corresponding greycode tracks. The physical cylinders are a subset (less than all) of the plurality of the greycode cylinders.

Abstract: An apparatus and method for dynamic head switch timing recalibration are provided. With the apparatus and method, a determination is made as to whether a difference in a reference head switch timing and the head switch timing at a later time is sufficient to meet a certain criteria. If the difference meets the criteria, a recalibration of the head switch timing is performed. For example, in a preferred embodiment, the criteria is a number of address mark (AM) misses during a head switch operation. If this predetermined number of AM misses is detected, then it is determined that a recalibration is necessary since the predetermined number of AM misses is an indication that the head switch timing has changed significantly from the reference head switch timing.

Abstract: An apparatus and method for dynamic head switch timing recalibration are provided. With the apparatus and method, a determination is made as to whether a difference in a reference head switch timing and the head switch timing at a later time is sufficient to meet a certain criteria. If the difference meets the criteria, a recalibration of the head switch timing is performed. For example, in a preferred embodiment, the criteria is a number of address mark (AM) misses during a head switch operation. If this predetermined number of AM misses is detected, then it is determined that a recalibration is necessary since the predetermined number of AM misses is an indication that the head switch timing has changed significantly from the reference head switch timing.

Abstract: Using a “reference” sensor, a reference position is detected in a frame of reference that is moving along a predetermined path relative to the reference sensor. The reference position is used to derive a position-dependent indicator of a position-dependent “longitudinal” offset component (i.e. along the path). An output from the target sensor is monitored using a “target window” that is partially based on the position-dependent indicator.