Abstract: A method for monitoring a data storage medium is provided in which a virtual head fly profile is measured. In addition, a data storage device for implementing the monitoring method is provided.

Abstract: Embodiments of the present invention include a method and an apparatus for generating an optimal MRO for a zone having a plurality of tracks. A disc drive controller determines the optimum MRO of a zone of tracks by analyzing multiple tracks in the zone with the actuator arm located at a series of offsets relative to the track center. Selected tracks in the zone are written to once. Then the selected tracks in the zone are sequentially read at a first offset, and the corresponding errors recorded. This reading is repeated for each of the offsets until all offsets have been analyzed. Based on the offset, or band of offsets, with the least errors over the selected tracks, the optimum MRO can be selected for the zone. The process can be repeated for each zone and the optimum MRO values stored in an MRO table in the disc drive for use during subsequent read and write operations.

Abstract: Method and apparatus for determining a signal-to-noise ratio (SNR) value from a readback signal, such as in a data storage device. A readback signal is obtained by a receiver (such as a data transducing head) coupled to a data recovery channel having a variable gain amplifier (VGA) and a threshold detector (TD). The data channel applies a selectable VGA gain value to the readback signal while errors are accumulated using a selectable error detection threshold from the TD. The SNR value is determined at least from a magnitude of the error detection threshold, and preferably from first and second VGA gain values using a linear regression model. The determined SNR value is highly correlated to classical SNR values obtained using external equipment such as an analyzer or oscilloscope, and is advantageously used in automated fashion during high volume manufacturing certification testing.

Abstract: A method and apparatus produce a read signal using a read head. A variable gain value is set that is used by a variable gain amplifier to amplify the read signal. The variable gain value is used to determine whether the head is functioning properly.

Abstract: Embodiments of the present invention include a method and an apparatus for generating an optimal MRO for a zone having a plurality of tracks. A disc drive controller determines the optimum MRO of a zone of tracks by analyzing multiple tracks in the zone with the actuator arm located at a series of offsets relative to the track center. Selected tracks in the zone are written to once. Then the selected tracks in the zone are sequentially read at a first offset, and the corresponding errors recorded. This reading is repeated for each of the offsets until all offsets have been analyzed. Based on the offset, or band of offsets, with the least errors over the selected tracks, the optimum MRO can be selected for the zone. The process can be repeated for each zone and the optimum MRO values stored in an MRO table in the disc drive for use during subsequent read and write operations.

Abstract: A method and apparatus produce a read signal using a read head. A variable gain value is set that is used by a variable gain amplifier to amplify the read signal. The variable gain value is used to determine whether the head is functioning properly.

Abstract: A method for monitoring a data storage medium is provided in which a virtual head fly profile is measured. In addition, a data storage device for implementing the monitoring method is provided.