Abstract: Motion of a first actuator in a multi-actuator drive is prevented from affecting a second actuator in the drive or from being affected by the second actuator. A coupling coordinator generates a hold command for the second actuator based on an operation to be carried out using the first actuator, where the hold command is generated before commands to carry out the operation are issued. The hold command may cause an aggressor actuator in the drive to halt a disturbance-generating operation being performed by the aggressor actuator or delay initiation of such an operation that is to be performed by the aggressor actuator. The hold command may cause a victim actuator in the drive to pause the execution of a sensitive operation being performed by the victim actuator or delay initiation of such an operation that is to be performed by the victim actuator.

Abstract: During in-drive writing of a servo spiral on a disk surface, a servo spiral can be distinguished during demodulation from adjacent servo spirals on the same disk surface. When a set of servo spirals is written on a disk surface, a first spiral is written to include a first identifying characteristic and the following spiral is written to include a second identifying characteristic. The identifying characteristic may include embedded sync marks encoding a certain numerical value, a unique frequency of high-low transitions included in each spiral, and/or a unique frame size.

Abstract: During in-drive writing of a servo spiral on a disk surface, a servo spiral can be distinguished during demodulation from adjacent servo spirals on the same disk surface. When a set of servo spirals is written on a disk surface, a first spiral is written to include a first identifying characteristic and the following spiral is written to include a second identifying characteristic. The identifying characteristic may include embedded sync marks encoding a certain numerical value, a unique frequency of high-low transitions included in each spiral, and/or a unique frame size.

Abstract: During a self-servo write process, servo sectors that have uniform radial spacing are written on a disk surface. As part of the in-drive writing of the servo sectors, a radial offset between a reader element and a writer element of a magnetic head is measured. The measured radial offset, or micro-jog, is compared to a known nominal micro-jog value for the current radial position of the magnetic head. When the measured micro-jog value does not match the nominal micro-jog value, an appropriate correction to the self-servo write step size is applied to the radial spacing between the servo sectors being written. Variations from ideal servo spiral slope that are inherent in some servo spirals can be compensated for, thereby improving the uniformity of radial spacing of data tracks associated with the servo sectors.

Abstract: A method of self servo-writing servo information to a plurality of disk surfaces in a disk drive that includes writing servo information to a plurality of disk surfaces in a first direction, writing servo information to a plurality of disk surfaces in a second direction, and determining an amount of overlap to be written on a reference surface with the reference head that will produce an overlap of servo information on each of the surfaces in the disk drive to which servo information is to be written. The method also includes switching to different tables when seeking across the overlap or border areas.

Abstract: A method of self servo-writing servo information to a plurality of disk surfaces in a disk drive that includes writing servo information to a plurality of disk surfaces in a first direction, writing servo information to a plurality of disk surfaces in a second direction, and determining an amount of overlap to be written on a reference surface with the reference head that will produce an overlap of servo information on each of the surfaces in the disk drive to which servo information is to be written. The method also includes switching to different tables when seeking across the overlap or border areas.

Abstract: A method of self servo-writing servo information to a plurality of disk surfaces in a disk drive that includes writing servo information to a plurality of disk surfaces in a first direction, writing servo information to a plurality of disk surfaces in a second direction, and determining an amount of overlap to be written on a reference surface with the reference head that will produce an overlap of servo information on each of the surfaces in the disk drive to which servo information is to be written. The method also includes switching to different tables when seeking across the overlap or border areas.

Abstract: A media includes a plurality of tracks, a preamble portion including a set of signals, a first servo burst having a first plurality of signals written substantially in phase with the preamble portion, and a second servo burst written out of phase with the preamble and the first servo portion. The media may be housed within a disk drive that includes a transducing head to read information from the media, and a read channel to read information from the disk including the information associated with the first servo burst and the second servo burst.

Abstract: A method of measuring a track value is shown. The track value is related to track mis-registration, and is compared to a track value limit to assess a condition of the track. In example embodiments, the track value is determined as a function of multiple position error signals from previous wedges in the track. During a self servo writing operation, the track value and the track value limit are used to selectively perform a recovery action. In example embodiments, the track value limit is dynamically adjusted.

Abstract: A method of measuring a track value is shown. The track value is related to track mis-registration, and is compared to a track value limit to assess a condition of the track. In example embodiments, the track value is determined as a function of multiple position error signals from previous wedges in the track. During a self servo writing operation, the track value and the track value limit are used to selectively perform a recovery action. In example embodiments, the track value limit is dynamically adjusted.

Abstract: A method for locating a track on a disk surface having a plurality of wedges of servo information includes demodulating servo information for a first servo wedge, and determining a correction factor for a written in repeatable runout for the servo information for the first servo wedge before demodulating servo information for a second servo wedge. A machine-readable medium provides instructions that perform the above method. A disk drive includes a processor disk that performs the above method and generates a signal to position a transducer over a desired track.

Abstract: A media includes a plurality of tracks, a preamble portion including a set of signals, a first servo burst having a first plurality of signals written substantially in phase with the preamble portion, and a second servo burst written out of phase with the preamble and the first servo portion. The media may be housed within a disk drive that includes a transducing head to read information from the media, and a read channel to read information from the disk including the information associated with the first servo burst and the second servo burst.

Abstract: A media includes a plurality of tracks, a preamble portion including a set of signals, a first servo burst having a first plurality of signals written substantially in phase with the preamble portion, and a second servo burst written out of phase with the preamble and the first servo portion. The media may be housed within a disk drive that includes a transuding head to read information from the media, and a read channel to read information from the disk including the information associated with the first servo burst and the second servo burst.

Abstract: A method of self servo-writing servo information to a plurality of disk surfaces in a disk drive that includes writing servo information to a plurality of disk surfaces in a first direction, writing servo information to a plurality of disk surfaces in a second direction, and determining an amount of overlap to be written on a reference surface with the reference head that will produce an overlap of servo information on each of the surfaces in the disk drive to which servo information is to be written. The method also includes switching to different tables when seeking across the overlap or border areas.

Abstract: A media includes a plurality of tracks, a preamble portion including a set of signals, a first servo burst having a first plurality of signals written substantially in phase with the preamble portion, and a second servo burst written out of phase with the preamble and the first servo portion. The media may be housed within a disk drive that includes a transducing head to read information from the media, and a read channel to read information from the disk including the information associated with the first servo burst and the second servo burst.

Abstract: A two-step self-servowriting process first writes an intermediate pattern based on a reference pattern, and then writes a final pattern based on the intermediate pattern, wherein the reference pattern can be a printed media or a spiral pattern. Such an approach can be utilized to reduce the noise/runout, eliminate timing eccentricity, and increase the sample rate of the final pattern. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

Abstract: Methods in accordance with the present invention can include determining a position of a head along a stroke by locating one or more marker-zones printed to a reference surface of a disk. The one or more marker-zones can be printed to a portion of the reference surface as one or more pulses from a template pattern that can further comprise a plurality of chevrons. In one embodiment, each pulse can trace the motion of the stroke along at least a portion of the radius of the reference surface. A pulse can identify a marker-zone edge when the pulse disappears at some radius from the center of the disk. By moving the head along the stroke, the marker-zone edge can be detected and a gross position determined. A fractional position can be determined by measuring a phase of a chevron located at substantially the same radial location as the edge.

Abstract: Template patterns in accordance with the present invention can include one or more marker-zones printed to a reference surface of a disk for determining gross-position along a stroke of a read head connected with a rotary actuator. The one or more marker-zones can be printed or otherwise written to a portion of the reference surfaces as one or more pulses. In one embodiment, each pulse can trace the motion of the stroke along at least a portion of the radius of the reference surface. A pulse can identify a marker-zone edge when a di-bit (a transition pair representing a pulse) disappears at some radius from center of the disk. At a radius closer to the center of the disk, the di-bit can abruptly reappear so that the pulse is continued. The interruption in the radial continuity of the magnetized pulse defines the marker-zone and can be any length.

Abstract: A two-step self-servowriting process first writes an intermediate pattern based on a reference pattern, and then writes a final pattern based on the intermediate pattern, wherein the reference pattern can be a printed media or a spiral pattern. Such an approach can be utilized to reduce the noise/runout, eliminate timing eccentricity, and increase the sample rate of the final pattern. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

Abstract: Methods in accordance with the present invention can include determining a position of a head along a stroke by locating one or more marker-zones printed to a reference surface of a disk. The one or more marker-zones can be printed to a portion of the reference surface as one or more pulses from a template pattern that can further comprise a plurality of chevrons. In one embodiment, each pulse can trace the motion of the stroke along at least a portion of the radius of the reference surface. A pulse can identify a marker-zone edge when the pulse disappears at some radius from the center of the disk. By moving the head along the stroke, the marker-zone edge can be detected and a gross position determined. A fractional position can be determined by measuring a phase of a chevron located at substantially the same radial location as the edge.