The present disclosure describes aspects of pulse-based writing for magnetic storage media. In some aspects, a pulse-based writer of magnetic storage media determines that a string of data bits having a same polarity corresponds to a magnet longer than a threshold associated with a magnetic media writer. The pulse-based writer inserts, into the string of data bits, a transition to a polarity opposite to the same polarity of the string of data bits. The string of data bits including the inserted transition is then transmitted to the magnetic media writer to cause a write head of the writer to pulse while writing the magnet to magnetic storage media. Various aspects may also implement a control signal to mask a transition or control polarity of the magnetic media writer. By so doing, magnets may be written to the magnetic storage media more efficiently or with less distortion to neighboring tracks.

Circuits for measuring a leakage current of one or more capacitors coupled to a power supply line that powers an apparatus, such as a storage device, are disclosed. In one embodiment, the circuit includes first and second resistors between the power supply line, and first and second respective switches to ground. A controller may charge the voltage line to a first voltage. Thereafter, the controller discharges the first voltage to a second voltage via the first resistor during a first identified time. After recharging the voltage line, the controller then discharge the first voltage to the second voltage via at least the second resistor during a second identified time. The controller determines the parasitic resistance using the first and second identified times, and then the leakage current from the parasitic resistance. Removing the leakage current factor from subsequent measurements can greatly improve testing accuracy and can avoid false positives in the testing process that would otherwise require removal of drives or other systems that are working properly.

A data storage device is disclosed comprising a head actuated over a disk, and a two-dimensional (2D) equalizer comprising a plurality of coefficients. A plurality of stored coefficients are accessed based on a first off-track offset of the head in order to first initialize the coefficients of the 2D equalizer, and then the coefficients of the 2D equalizer are first adapted based at least on a first read signal to generate first adapted coefficients. The plurality of stored coefficients are accessed based on a second off-track offset of the head in order to second initialize the coefficients of the 2D equalizer, and then the coefficients of the 2D equalizer are second adapted based at least on the first read signal to generate second adapted coefficients.

The embodiments of the invention improve the traditional disk drives by eliminating the mechanical actuator assembly that moves the read-write head attached to the actuator assembly, and replacing it with multiple read-write heads mounted over one or more rotating platters. The number of the read-write heads is preferably sufficiently large so that the read-write heads cover all tracks on the one or more rotating platters. In one embodiment, a disk includes a rotatable platter, a central spindle to rotate the rotatable platter arounds an axis, an electric motor to drive the central spindle, and multiple read-write heads mounted over the rotatable platter. In one embodiment, the platter includes multiple tracks arranged in form of concentric circles, where each of the read-write heads performs read-write operations on one of the tracks, and each track is assigned at least one of the multiple read-write heads.

The embodiments of the invention improve the traditional disk drives by eliminating the mechanical actuator assembly that moves the read-write head attached to the actuator assembly, and replacing it with multiple read-write heads mounted over one or more rotating platters. The number of the read-write heads is preferably sufficiently large so that the read-write heads cover all tracks on the one or more rotating platters. In one embodiment, a disk includes a rotatable platter, a central spindle to rotate the rotatable platter arounds an axis, an electric motor to drive the central spindle, and multiple read-write heads mounted over the rotatable platter. In one embodiment, the platter includes multiple tracks arranged in form of concentric circles, where each of the read-write heads performs read-write operations on one of the tracks, and each track is assigned at least one of the multiple read-write heads.

A storage device includes a transducer head with multiple write elements having write poles of different sizes. For example, the transducer head may include two write poles of different width configured to write to a same surface of a storage medium. A controller of the storage device is configured to selectively engage one of the multiple write elements to write data to the storage medium.

The present disclosure describes aspects of pulse-based writing for magnetic storage media. In some aspects, a pulse-based writer of magnetic storage media determines that a string of data bits having a same polarity corresponds to a magnet longer than a threshold associated with a magnetic media writer. The pulse-based writer inserts, into the string of data bits, a transition to a polarity opposite to the same polarity of the string of data bits. The string of data bits including the inserted transition is then transmitted to the magnetic media writer to cause a write head of the writer to pulse while writing the magnet to magnetic storage media. Various aspects may also implement a control signal to mask a transition or control polarity of the magnetic media writer. By so doing, magnets may be written to the magnetic storage media more efficiently or with less distortion to neighboring tracks.

Circuits for measuring a leakage current of one or more capacitors coupled to a power supply line that powers an apparatus, such as a storage device, are disclosed. In one embodiment, the circuit includes first and second resistors between the power supply line, and first and second respective switches to ground. A controller may charge the voltage line to a first voltage. Thereafter, the controller discharges the first voltage to a second voltage via the first resistor during a first identified time. After recharging the voltage line, the controller then discharge the first voltage to the second voltage via at least the second resistor during a second identified time. The controller determines the parasitic resistance using the first and second identified times, and then the leakage current from the parasitic resistance. Removing the leakage current factor from subsequent measurements can greatly improve testing accuracy and can avoid false positives in the testing process that would otherwise require removal of drives or other systems that are working properly.

A magnetic tape reading apparatus including: a reading head which includes a reading unit disposed at a position corresponding to a single track included in a magnetic tape; a controller which controls the reading unit to read data plural times from a specific range of the single track in a running direction of the magnetic tape by a linear scan method; and a synthesis unit which synthesizes a plurality of reproducing signal sequences obtained by reading data plural times from the specific range by the reading unit.

According to one embodiment, first setting information and second setting information are stored in a memory included in a magnetic disk device. The first setting information indicates a second track that is a first track set to be disused on the basis of a defect inspection among a plurality of first tracks included in a magnetic disk. The second setting information indicates a third track selected from one or more first tracks different from the second track. In a case where an access destination is a user area, the controller converts logical address information into physical address information while slipping the second track and the third track. In a case where an access destination is a system area, the controller converts logical address information into physical address information while slipping all of the first tracks other than the third track among the plurality of first tracks.