Abstract: A method for determining whether a data storage device read/write head is a low-flying read/write head or a non low-flying read/write head. A disc attached to a spindle motor is accelerated to an operating rotational velocity, the head is positioned over a portion of the disc non-accessible to customer data and a data pattern of selected frequency is written. A magnetoresistive element of the is biased and the data pattern is read while the disc is decelerated to a predetermined rotational velocity threshold. Occurrence of a read signal landing signature comprising readback signal amplitude modulation prior to reaching the predetermined rotational velocity threshold identifies the head as a low-flying head. Contrawise, non-occurrence of the read signal landing signature prior to reaching the predetermined rotational velocity threshold signifies the head as a non low-flying head.

Abstract: A method for determining whether a data storage device read/write head is a low-flying read/write head or a non low-flying read/write head. A disc attached to a spindle motor is accelerated to an operating rotational velocity, the head is positioned over a portion of the disc non-accessible to customer data and a data pattern of selected frequency is written. A magnetoresistive element of the is biased and the data pattern is read while the disc is decelerated to a predetermined rotational velocity threshold. Occurrence of a read signal landing signature comprising readback signal amplitude modulation prior to reaching the predetermined rotational velocity threshold identifies the head as a low-flying head. Contrawise, non-occurrence of the read signal landing signature prior to reaching the predetermined rotational velocity threshold signifies the head as a non low-flying head.

Abstract: A method for improving read error rates in a disc drive employing repeatable run-out compensation for writing but not for reading is disclosed. Pursuant to the method, a repeatable run-out compensation system which compensates for repeatable run-out during write operations but not during read operations is implemented. After implementing the repeatable run-out compensation system, reader-to-writer offset calibration is performed. In one embodiment of the present invention, after implementing the repeatable run-out compensation system, read error rates are experimentally determined for a given data track across a range of reader-to-writer offset values. Then a curve representing read error rates as a function of reader-to-writer offset is generated. The optimum reader-to-writer offset is then determined based on the shape of the curve. A disc drive employing this method is also disclosed.

Abstract: A method for optimizing data transfer performance in a disc drive through selection of optimal reader/writer offsets and write fault thresholds. An initial offset for a selected track is determined as the radial distance between read and write elements of a head as the head is positioned adjacent a selected track. Asymmetric write fault thresholds are selected on opposing sides of the center of the selected track in relation to the ability of the read element to successfully recover data written to the track. An adjustment value is determined in relation to the asymmetry of the write fault thresholds, and the adjustment value is used to modify the initial offset to form a final offset, as well as to make the write fault thresholds symmetric about the center of the track.

Abstract: Method for optimizing parameter values in a read/write channel of a disc drive. A population of error rate points is obtained from selected ranges of a plurality of read/write channel parameters, each error rate point corresponding to a unique combination of parameter values and having an associated error rate value. A weight is determined for each of the error rate points through normalization to the minimum error rate value in the population. A threshold value is determined based upon the error rate values in a plurality of nominally identical disc drives and the weights are compared to the threshold value. Those error rate values having weights less than the threshold are selected and a center of gravity is determined therefrom. At such times that the entire population of error rate values has weights greater than the threshold value, the optimum parameter values are those that map to the center of gravity.