This application includes systems and techniques relating to storage devices, such as a device including: a first read channel to process a first input signal obtained from a storage medium using a first read head; a second read channel to process a second input signal obtained from the storage medium using a second read head, which is offset from the first read head in each of two dimensions; a single digital timing loop configured to control interpolation of timing of sampling for first and second analog to digital converters in the first and second read channels; and a two dimensional equalizer coupled with output lines of the first and second read channels; the device being configured to account for a fractional timing difference between the first input signal and the second input signal, the fractional timing difference being a fractional amount of a single clock cycle of the device.

Provided is an optical medium reproducing apparatus including: a detection unit that divides a luminous flux into a plurality of regions including a first region and a second region which are different in a position in a radial direction and/or a tangential direction, and combines a plurality of detection signals in correspondence with the amount of light that is incident to each of the plurality of regions with combination patterns which are selected to form signals of a plurality of channels; a multi-input equalizer unit that includes a plurality of equalizer units to which the signals of the plurality of channels are respectively supplied, computes outputs of the plurality of equalizer units, and outputs the resultant value as an equalization signal; and a binarization unit that performs binarization processing with respect to the equalization signal to obtain binary data. An addition signal channel including a constant multiplication of detection signals of the first region and the second region is included in at least one of the combination patterns.

In one embodiment, a system for processing data includes a processor and logic integrated with and/or executable by the processor. The logic is configured to detect and track positive peak amplitudes and negative peak amplitudes of a readback waveform during data reading using a tracking threshold module, and to detect and track positive peak amplitudes and negative peak amplitudes of the readback waveform during the data reading at an input to an equalizer using a second tracking threshold module in response to reading a data set separator (DSS). Moreover, the logic is configured to perform asymmetry compensation on the data using an asymmetry compensator in an asymmetry compensation loop based on input from the tracking threshold module when not reading a DSS and based on input from the second tracking threshold module when reading a DSS, an output of the asymmetry compensator being provided to the equalizer.

According to one embodiment, a system for processing data includes a processor and logic integrated with and/or executable by the processor. The logic is configured to individually set, for each of one or more range-constrained finite impulse response (FIR) filter taps configured for use in a FIR filter, a predetermined range of values suitable for controlling an equalizer response. The logic is also configured to pass data through the equalizer comprising the FIR filter to obtain equalized data. Each of the one or more range-constrained FIR filter taps are individually adaptive within its predetermined range of values. Also, the data is read from a magnetic storage medium.

The magnetic tape includes a non-magnetic support; and a magnetic layer in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference between a value L.sub.99.9 of a cumulative distribution function of 99.9% and a value L.sub.0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and a difference between a spacing S.sub.after measured on a surface of the magnetic layer by an optical interferometry after methyl-ethyl-ketone cleaning and a spacing S.sub.before measured on the surface of the magnetic layer by an optical interferometry before methyl-ethyl-ketone cleaning is greater than 0 nm and 15.0 nm or less.

The magnetic tape includes a non-magnetic support; and a magnetic layer in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference between a value L.sub.99.9 of a cumulative distribution function of 99.9% and a value L.sub.0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and a difference between a spacing S.sub.after measured on a surface of the magnetic layer by an optical interferometry after methyl-ethyl-ketone cleaning and a spacing S.sub.before measured on the surface of the magnetic layer by an optical interferometry before methyl-ethyl-ketone cleaning is greater than 0 nm and 15.0 nm or less.

Systems and methods for improving seek times in a read channel performing a read operation on a disk drive are disclosed. The method includes extrapolating, based on initial filter settings corresponding to a first user-data region or a first servo-data region and tracked settings varying over time, a proportionality constant for the programmable analog filter, in response to determining a new target frequency for the programmable analog filter corresponding to a second user-data region or a second servo-data region, computing new filter settings for the programmable analog filter based on the extrapolated proportionality constant, and transmitting, to the programmable analog filter, the computed new filter settings corresponding to the new target frequency of the second user-data region or the second servo-data region.

An apparatus may comprise a circuit configured to receive first underlying data corresponding to a first signal and receive a second signal corresponding to second underlying data. The circuit may determine an interference component signal based on the first underlying data corresponding to the first signal and a first channel pulse response shape for the first signal, determine estimated decisions corresponding to the second signal based on the second signal, and determine an estimated signal based on the estimated decisions corresponding to the second signal and a second channel pulse response shape for the second signal. The circuit may then generate a remaining signal based on the estimated signal and the second signal, generate an error signal based on the interference component signal and the remaining signal, and adapt one or more parameters of the first channel pulse response shape based on the error signal.

The magnetic tape includes a non-magnetic support; and a magnetic layer, in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference L.sub.99.9−L.sub.0.1 between a value L.sub.99.9 of a cumulative distribution function of 99.9% and a value L.sub.0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 or more and 0.40 or less.

The magnetic tape includes a non-magnetic support; and a magnetic layer in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference between a value L.sub.99.9 of a cumulative distribution function of 99.9% and a value L.sub.0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and a difference between a spacing S.sub.after measured on a surface of the magnetic layer by an optical interferometry after methyl-ethyl-ketone cleaning and a spacing S.sub.before measured on the surface of the magnetic layer by an optical interferometry before methyl-ethyl-ketone cleaning is greater than 0 nm and 15.0 nm or less.