This disclosure describes apparatuses and techniques for multi-channel servo demodulation. Multiple servo demodulation channels enable additional information to be obtained during the self-servo writing process, such as relative positions of multiple read heads and tracking of multiple servo patterns. This additional information enhances accuracy for self-servo writing and can lead to higher recording densities in media drives, and thus more storage with little or no additional cost.

According to one embodiment, a system includes a controller configured to determine whether a position error signal (PES) is invalid while reading data from a magnetic medium using at least one data channel. An invalid PES indicates off-track reading or a defect in the magnetic medium. The controller is also configured to determine whether a PES value is above a first predetermined threshold in response to a determination that the PES is valid. Moreover, the controller is configured to inject error bits into a data stream in place of corresponding bits of decoded data in response to a determination that the PES is invalid, a determination that the PES value is above the first predetermined threshold, or a determination that the PES is invalid and the PES value is above the first predetermined threshold. Other systems and methods are described in accordance with more embodiments.

Magnetic tape media according to one embodiment includes a plurality of servo tracks having physical characteristics of being written by an apparatus that monitors a lateral position of the magnetic tape media passing over a servo writing head during a servo track writing operation and writes servo marks to the magnetic tape media. A timing of the writing of each servo mark is based on the monitored position of the magnetic tape media. Magnetic tape media according to another embodiment include a plurality of servo tracks having a plurality of consecutively-written servo marks, a distance between each consecutively-written servo mark in a tape travel direction varying in direct correlation with a distance of the respective mark, as written, from an edge of the magnetic tape media in a cross-track direction.

The magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which the magnetic layer includes a timing-based servo pattern, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm.sup.3, an XRD intensity ratio Int(110)/Int(114) obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, and an edge shape of the timing-based servo pattern specified by magnetic force microscope observation is a shape in which a difference (L.sub.99.9L.sub.0.1) is equal to or smaller than 180 nm, and a magnetic tape device including the magnetic tape.

The magnetic tape device includes a magnetic tape and a TMR head (servo head), in which the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, an intensity ratio of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, and a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00.

The present disclosure generally relates to a tape drive comprising one or more tape head modules. Each tape head module comprises a chip and a beam, such as a u-beam. Each chip comprises a first data element array and a second data element array, where each data element array comprises 33 write elements or 33 read elements and one or more servo element pairs. Each data element of both the first and second data element arrays is coupled to two pads. The pads and the data element arrays of each chip are offset in a first direction such that the pads and data element arrays are offset from a central axis a distance about one-half the span of either the first or second data element array. Either the first data element array or the second data element arrays is centered upon the central axis.

The magnetic tape device includes: a magnetic tape; and a servo head, in which a magnetic tape transportation speed of the magnetic tape device is equal to or lower than 18 m/sec, the servo head is a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading element, the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, the magnetic layer includes a servo pattern, and a coefficient of friction measured regarding a base portion of a surface of the magnetic layer is equal to or smaller than 0.30.

A tape drive-implemented method, according to one embodiment, includes: determining a servo band configuration of servo bands on a magnetic tape, using servo readers on a magnetic tape head to read one or more of the servo bands based on the determined servo band configuration, and using information read from the one or more of the servo bands to position the magnetic tape head relative to the magnetic tape. An array of data transducers is positioned along the magnetic tape head, the array extending perpendicular to a direction of travel of the magnetic tape. Moreover, a group of the servo readers is positioned at each end of the array of data transducers, and a distance between each of the immediately adjacent servo readers in each of the groups of servo readers is less than or equal to one third of a prespecified width of each of the servo bands.

According to one embodiment, a system for processing data includes a controller configured to determine whether a position error signal (PES) is invalid while reading data from a magnetic medium using at least one data channel. The controller is also configured to determine whether a PES value is above a first predetermined threshold in response to a determination that the PES is valid. Moreover, the controller is configured to inject error bits into a data stream in place of corresponding bits of decoded data in response to a determination that the PES is invalid and in response to a determination that the PES value is above the first predetermined threshold. Other systems and methods for processing data are described in accordance with more embodiments.

According to one embodiment, a system includes a controller configured to determine whether a position error signal (PES) is invalid while reading data from a magnetic medium using at least one data channel. An invalid PES indicates off-track reading or a defect in the magnetic medium. The controller is also configured to determine whether a PES value is above a first predetermined threshold in response to a determination that the PES is valid. Moreover, the controller is configured to inject error bits into a data stream in place of corresponding bits of decoded data in response to a determination that the PES is invalid, a determination that the PES value is above the first predetermined threshold, or a determination that the PES is invalid and the PES value is above the first predetermined threshold. Other systems and methods are described in accordance with more embodiments.