According to one embodiment, a magnetic disk device includes a disk, a head, a storage unit, and a controller. The storage unit stores a reference table and an adjustment table. The reference table has a plurality of reference counts, which are m reference counts. The adjustment table has a plurality of adjustment values, which are n adjustment values. The controller includes a detector, an adjustment unit that adjusts a reference count corresponding to a case where abnormality information is detected to an ATI rewrite count having a numerical value different from the reference count, a counter, a determination unit, and a refresh processing unit.

An optical disc device includes: an optical disc drive that reads data from a plurality of optical discs in which user data is recorded while distributed in the plurality of optical discs; a memory unit in which data read from an optical disc of a first group that is a part of the plurality of optical discs is recorded through the optical disc drive; and a controller that reproduces the user data from data of a remaining optical disc except for the first group, the data of the remaining optical disc being read through the optical disc drive, and the data recorded in the memory unit.

Various embodiments for error recovery in a data storage environment, by a processor device, are provided. For monitoring signal from one or more read channels in a tape storage drive, a variable range of offsets organized by row into a table is selected by a microcode algorithm and applied by a track following servo mechanism of the tape storage drive to position a read head in relation to a track of a tape media at an offset up to and including beyond a predetermined margin of the track.

Various embodiments for error recovery in a data storage environment, by a processor device, are provided. For monitoring signal from one or more read channels in a tape storage drive, a variable range of offsets organized by row into a table is selected by a microcode algorithm and applied by a track following servo mechanism of the tape storage drive to position a read head in relation to a track of a tape media at an offset up to and including beyond a predetermined margin of the track.

The presently disclosed technology teaches integrating disc drive electronics into a transducer head. Decreased electrical transit times and data processing times can be achieved by placing the electronics on or within the transducer head because electrical connections may be made physically shorter than in conventional systems. The electronics may include one or more of a control system circuit, a write driver, and/or a data buffer. The control system circuit generates a modified clock signal that has a fixed relation to phase and frequency of a bit-detected reference signal that corresponds to positions of patterned bits on the disc. The write driver writes outgoing data bits received from an external connection to off-head electronics directly to the writer synchronized with the modified clock signal. The data buffer stores and converts digital data bits sent from the off-head electronics to an analog signal that is synchronized with the modified clock signal.

In a storage device, data is written to tracks on a storage medium. Data for each track includes a preamble. The preamble in any current track is orthogonal to the preamble in any track adjacent to the current track. A first read head is positioned over the current track and off-center toward a first adjacent track on a first side of the current track to detect first signals from among the current track, the first adjacent track, and a second adjacent track on a second side of the current track. A second read head is positioned over the current track and off-center relative to the current track toward the second adjacent track to detect second signals from among the current track, the first adjacent track, and the second adjacent track. Analyzing the first and second signals determines an amount by which the read heads are off-track from the current track.

An apparatus comprises a slider configured for heat-assisted magnetic coupled to a controller. The slider comprises a writer, a heater, a near-field transducer, and an optical waveguide for communicating light from a laser diode to the near-field transducer. The controller is configured to set a target pre-write clearance of the slider prior to performing a write operation, set a target write clearance of the slider for performing the write operation, and determine a difference between the target pre-write and write clearances to define a target pre-write clearance offset. The controller is also configured to measure, for a plurality of different target pre-write clearance offsets, a writability metric for the slider while sweeping a laser diode current, and adjust the target pre-write clearance offset so that the writability metric reaches a predetermined threshold. The controller is further configured to perform subsequent write operations using the adjusted target pre-write clearance offset.

Operations include compensating for a Tracking Error Signal (TES) offset in an optical tape drive. The tracking error offset compensation system detects a control signal for controlling movement of an optical head across a surface of a tape. The tracking error offset compensation system computes an estimated movement of the optical head, based on the initial control signal. The tracking error offset compensation system determines an estimated TES offset, based on the estimated movement of the optical head. The tracking error offset compensation system uses the estimated TES offset to correct a TES. The tracking error offset compensation system transmits the corrected TES, for controlling additional movement of the optical head.

An optical disc device includes: an optical disc drive that reads data from a plurality of optical discs in which user data is recorded while distributed in the plurality of optical discs; a memory unit in which data read from an optical disc of a first group that is a part of the plurality of optical discs is recorded through the optical disc drive; and a controller that reproduces the user data from data of a remaining optical disc except for the first group, the data of the remaining optical disc being read through the optical disc drive, and the data recorded in the memory unit.

A phono cartridge transmission line impedance matching system is provided. The phono cartridge transmission line impedance matching system comprises a connecting port adapted for being connected to a signal line and a ground line of a phono cartridge transmission line. A capacitance switching circuit is connected to the signal line and the ground line in a parallel fashion. The capacitance switching circuit is adapted for selectively switching between different capacitances. A plurality of resistance switching circuits, connected with each other in a serial fashion, are connected to the signal line and the ground line in a parallel fashion. Each resistance switching circuit is adapted for selectively switching between different resistances.