Abstract: A method of generating a position error signal for a desired radial position of a read/write head relative to a data track of a disk is disclosed. The track has a plurality of servo bursts defining a plurality of servo nulls for the track, and are positioned such that they are at more than four different radial positions relative to the track, and define a predetermined locus having a known position relationship with the track. The method comprises determining a target null position on the null locus corresponding to the radial position of the head relative to the track; detecting the position of the servo null with the head; determining from the detected servo null position the position error of the head relative to the target null position; and, generating a position error signal.

Abstract: A method of controlling the position of a read/write head relative to a disk in a test apparatus is disclosed. The test apparatus has a positioner for positioning the head. The positioner has a sensor to measure the actual position achieved by the positioner. The method includes generating a sensor signal measuring the actual position achieved by the positioner; generating a position error signal of the head relative to the disk detected at the head; high pass filtering the head position error signal and low pass filtering the sensor signal so that there is substantially no overlap in frequency between them; and, deriving a low frequency head error signal from the head position error signal corresponding to any drift of the head.

Abstract: A method of controlling the position of a read/write head relative to a disk in a test apparatus is disclosed. The test apparatus has a positioner for positioning the head. The positioner has a sensor to measure the actual position achieved by the positioner. The method includes generating a sensor signal measuring the actual position achieved by the positioner; generating a position error signal of the head relative to the disk detected at the head; high pass filtering the head position error signal and low pass filtering the sensor signal so that there is substantially no overlap in frequency between them; and, deriving a low frequency head error signal from the head position error signal corresponding to any drift of the head.

Abstract: Methods and apparatus are disclosed for writing and verifying servo frames written on a storage medium, for verifying data areas of a storage medium, and for writing and verifying servo frames and data areas of a storage medium. In one example, the writing of at least a portion of a position field of a servo frame to a track of the storage medium is interleaved with reading of at least a portion of a previously written logic field of a servo frame of a track of the storage medium whereby said portion of the previously written logic field can be verified during the servo writing process.

Abstract: Apparatus for loading a read/write head to a spinstand has a load area for receiving at least one head to be tested. The apparatus further has a first station having a coarse precisor arranged to provide a coarse positioning of the head. A first automation device is arranged to pick a head from the load area and to deliver it to the coarse precisor. The apparatus has a deck having a test station at which a head can be tested. The deck has a fine precisor arranged to provide a second, fine positioning of the head. A second automation device is arranged to pick a head from the first station and deliver it to the fine precisor where the head can be subjected to a second, fine precising and to pick a head from the fine precisor and to deliver it to the test station.

Abstract: A method of generating a position error signal for a desired radial position of a read/write head relative to a data track of a disk is disclosed. The track has a plurality of servo bursts defining a plurality of servo nulls for the track, and are positioned such that they are at more than four different radial positions relative to the track, and define a predetermined locus having a known position relationship with the track. The method comprises determining a target null position on the null locus corresponding to the radial position of the head relative to the track; detecting the position of the servo null with the head; determining from the detected servo null position the position error of the head relative to the target null position; and, generating a position error signal.

Abstract: Apparatus for loading a read/write head to a spinstand has a load area for receiving at least one head to be tested. The apparatus further has a first station having a coarse precisor arranged to provide a coarse positioning of the head. A first automation device is arranged to pick a head from the load area and to deliver it to the coarse precisor. The apparatus has a deck having a test station at which a head can be tested. The deck has a fine precisor arranged to provide a second, fine positioning of the head. A second automation device is arranged to pick a head from the first station and deliver it to the fine precisor where the head can be subjected to a second, fine precising and to pick a head from the fine precisor and to deliver it to the test station.

Abstract: Methods and apparatus are disclosed for writing and verifying servo frames written on a storage medium, for verifying data areas of a storage medium, and for writing and verifying servo frames and data areas of a storage medium. In one example, the writing of at least a portion of a position field of a servo frame to a track of the storage medium is interleaved with reading of at least a portion of a previously written logic field of a servo frame of a track of the storage medium whereby said portion of the previously written logic field can be verified during the servo writing process.