Abstract: According to one embodiment, physical position information on errors on a recording medium is acquired, physical position relationship between the errors on the recording medium is calculated based on the position information, and a failure mode related to the errors is determined based on the position relationship.

Abstract: According to one embodiment, physical position information on errors on a recording medium is acquired, physical position relationship between the errors on the recording medium is calculated based on the position information, and a failure mode related to the errors is determined based on the position relationship.

Abstract: When a combination head is on-tracked to an arbitrary cylinder position, a head position controller corrects a head position so as to eliminate an offset amount derived from an offset table. A bias current setting circuit obtains a current set value corresponding to an offset correction amount from a bias current table and supplies the bias current according to the current set value to an MR head. As kinds of offsets, there are a yaw angle offset, a thermal offset, and a core deviation offset.

Abstract: A device for recording and reproducing data on a recording media includes an error detecting unit for detecting a defective sector by reading the data from the media, a data copying unit for copying the data of the defective sector to at least one temporary replacing sector, a test unit for testing whether the defective sector has a media defect, and a replacement unit for replacing the defective sector with a spare sector by copying the data of the at least one temporary replacing sector to the spare sector when the defective sector has the media defect.

Abstract: Servo information is written on a magnetic disk at intervals equivalent to 1/N of where the period at the position of a head is controlled. When the frequency characteristic of a servo loop is measured, a servo controller generates a position signal, which indicates deviation of the head from a reference position, using servo information at a first sampling point, calculates an actuator drive current command value, which drives an actuator, on the basis of the position signal, and controls the actuator based upon the current command value. Further, the servo controller executes processing for generating the position signal, but does not calculate the actuator drive current command value, on the basis of servo information at second through Nth sampling points.

Abstract: A magnetic disc apparatus using an electric filter for waveform equalization of a read signal is provided. The optimum parameters are set for every head and the writing and reading operations are executed on the basis of the optimum characteristics. At the start of the use of the apparatus, the control information of the circuit parameters previously recorded on a magnetic recording medium is read out, thereby forming a set value table in which the optimum values of the circuit parameters including at least the electric filter have been stored every magnetic head. After the table was formed, prior to the writing or reading operation, the contents of the set value table corresponding to the designated magnetic head are read out and the circuit parameters of the circuit section including the electric filter are controlled and optimized on the basis of the contents read out.