Abstract: According to one embodiment, a magnetic disk device includes a magnetic disk, a magnetic head, and a controller. The magnetic disk has a plurality of tracks. The magnetic head performs reading and writing from and to the magnetic disk. The controller controls write operations to a first region and a second region of the magnetic disk in different manners. The second region is narrower in track pitch than the first region.

Abstract: According to one embodiment, a magnetic disk device includes a magnetic disk, a magnetic head, and a controller. The magnetic disk has a plurality of tracks. The magnetic head performs reading and writing from and to the magnetic disk. The controller controls write operations to a first region and a second region of the magnetic disk in different manners. The second region is narrower in track pitch than the first region.

Abstract: According to one embodiment, there is provided a magnetic disk apparatus including an actuator, a shock detection circuit, a temperature measurement circuit, and a controller circuit. The actuator holds a magnetic head that accesses a magnetic disk. The shock detection circuit includes an acceleration sensor that detects acceleration during driving of the actuator. The temperature measurement circuit measures a temperature during driving of the actuator. The controller circuit changes sensitivity of the shock detection circuit according to a temperature change rate obtained from the measured temperature.

Abstract: According to one embodiment, a disk device comprises a memory, detector, calculation module, and deactivation module. The memory is configured to store an offset control amount at a time of manufacture. The detector is configured to detect a disk run-out. The calculation module is configured to obtain an offset control amount when the detector detects the disk run-out. The deactivation module is configured to deactivate the offset control based on a difference between the offset control amount obtained by the calculation module and the offset control amount at a time of manufacture stored in the memory and based on the offset control amount obtained by the calculation module.

Abstract: A probe for an electrical test has a foot portion coupled with a board, an arm portion extending laterally from a lower end portion of the foot portion, and a needle tip portion projecting downward from a tip end portion of the arm portion. At least one selected from a group consisting of the foot portion, the arm portion, and the needle tip portion comprises a symbol specifying a position of the probe on the board.

Abstract: According to one embodiment, a disk device comprises a memory, detector, calculation module, and deactivation module. The memory is configured to store an offset control amount at a time of manufacture. The detector is configured to detect a disk run-out. The calculation module is configured to obtain an offset control amount when the detector detects the disk run-out. The deactivation module is configured to deactivate the offset control based on a difference between the offset control amount obtained by the calculation module and the offset control amount at a time of manufacture stored in the memory and based on the offset control amount obtained by the calculation module.

Abstract: According to one embodiment, a disk device comprises a magnetic head module, a measurement module, and an arithmetic operation module. The magnetic head module includes a read head and a write head wherein an offset is present therebetween. The measurement module writes a measurement signal into a disk medium, reads the measurement signal while moving the read head in the radial direction, and obtains a measurement value of the offset based on a level of the read measurement signal. The arithmetic operation module obtains an estimate value of a distance between the write head and the read head based on a design value of the distance, a design value of the offset calculated by the design value of the distance, and the measurement value of the offset.