Abstract: A method to adjust the orientation of a read head comprising a first read element and a second read element, wherein the first read element and the second read element are separated by a distance, wherein the method moves a sequential information storage medium adjacent to the read head, determines a skew angle for the sequential information storage medium with respect to the read head using the first read element and the second read element, and encodes that skew angle in a computer readable medium.

Abstract: An apparatus, system, and method are disclosed for a tape drive head. An upper servo element reads an upper servo track conforming to a specified format. A lower servo element reads a lower servo track conforming to the specified format. A mid servo element reads a mid servo track. The mid servo element is disposed between the upper servo element and the lower servo element. Sixteen legacy read elements are disposed between the upper server element and the lower servo element. The legacy read elements read legacy data tracks conforming to the specified format. At least eight incremental read elements are interleaved between the legacy read elements. One incremental read element is adjacent to each legacy read element on a side of the legacy read element away from the mid servo element.

Abstract: Dynamic calibration of a secondary velocity signal is provided in a tape drive. In one example, a reel motor is operated to drive a reel carrying a tape in a tape drive. The motion of the tape is measured to provide a measured primary velocity signal of the tape, and in addition, the operation of the reel motor is measured to provide an estimated secondary velocity signal of the tape as a function of motor parameters and the motor operation measurements. The estimated secondary velocity signal of the tape may be calibrated as the tape is driven, as a function of the tape motion measurements and the motor operation measurements. Other embodiments are described and claimed.

Abstract: A method to adjust the positions of a write element and read element disposed on a read/write head comprising a first assembly independently moveable along a first axis and comprising a first servo element, a second servo element, and the write element disposed between the first servo element and the second servo element and a second assembly independently moveable along the first axis and comprising a third servo element, a fourth servo element, and the read element disposed between the third servo element and the fourth servo element. The method moves a sequential information storage medium adjacent to the read/write head along a second axis, wherein the second axis is substantially orthogonal to the first axis, and determines a dynamic skew for the sequential information storage medium with respect to the read/write head using the first servo element and the second servo element. The method then positions the first assembly with respect to the second assembly to correct for that dynamic skew angle.

Abstract: An apparatus, system, and method are disclosed for detecting a periodic sequence. A value detector module detects a plurality of values of a periodic sequence. In one embodiment, a transformation module transforms the plurality of values into transformed values. A confinement module confines the values to a limited set of confined values. A correlation module correlates the confined values with a plurality of instances of the periodic sequence. In addition, a selection module selects an instance of the periodic sequence with the highest correlation to the confined values as an observed periodic sequence.

Abstract: Methods, magnetic tape data storage drives, data storage systems, and magnetic tape data storage cartridges. A system having at least one magnetic tape data storage drive is configured to handle a magnetic tape cartridge comprising a magnetic tape data storage media and accompanying cartridge memory. The magnetic tape media comprises a plurality of longitudinal servo bands, the servo bands separated by data bands. Two servo bands, each at opposite sides of a data band are sensed. In response to at least one servo detection error signal of one of the two servo bands, an edge stress signal is set to the cartridge memory of the magnetic tape cartridge. Then, for example, after reloading the cartridge, the cartridge memory is inspected for a set edge stress signal; and, if the edge stress signal is set, only read operations are allowed with respect to the inspected magnetic tape data storage cartridge.

Abstract: Provided are a method, storage controller, and tape drive for adjusting read heads based on misregistration calculated from servo patterns. A plurality of first read heads read a plurality of servo patterns on a storage medium. A determination is made from the read servo patterns a skew at which the first read heads are positioned with respect to the servo patterns written to the storage medium. A determination is made of an adjustment factor to eliminate the determined skew. A plurality of second read heads that read the storage medium are adjusted by the adjustment factor.

Abstract: An apparatus for controlling a wheel motor is provided. A plurality of switches is provided for controlling a direction of current through motor coils of the wheel motor. A brushless motor control circuit is connected to each of the plurality of switches. Responsive to a request to adjust one of an angular velocity and an angular acceleration of the wheel motor, the plurality of switches are activated to place the motor coils in a predetermined configuration to maximize torque or reduce a total back electromotive force (BEMF) from the motor coils.

Abstract: A sequential information storage medium, comprising a plurality of servo patterns encoded lengthwise thereon, wherein each servo pattern encodes at least one LPOS bit and comprises a width less than 187 microns.

Abstract: Handling a magnetic tape cartridge comprises the steps of reading cartridge mount information from the cartridge memory; determining from the cartridge mount information whether the present mount is the first mount of the magnetic tape cartridge; and if so, fast forward and rewind the magnetic tape of the magnetic tape cartridge, e.g., the fast forward is to end of tape (EOT) and the rewind is to beginning of tape (BOT). Alternatively, if the cartridge mount information indicates the present mount is the first mount of the magnetic tape cartridge; monitoring input/output with respect to the magnetic tape cartridge for write errors during the mount; determining whether the number of monitored write errors meets a predetermined threshold; and if so, fast forward and rewind the magnetic tape of the magnetic tape cartridge.

Abstract: Provided are a method, storage controller, and tape drive for adjusting read heads based on misregistration calculated from servo patterns. A plurality of first read heads read a plurality of servo patterns on a storage medium. A determination is made from the read servo patterns a skew at which the first read heads are positioned with respect to the servo patterns written to the storage medium. A determination is made of an adjustment factor to eliminate the determined skew. A plurality of second read heads that read the storage medium are adjusted by the adjustment factor.

Abstract: A storage drive implements a method for a BEMF voltage reduction during a deceleration period of an electric motor of the storage drive. In operation, the electric motor is disconnected from a power supply during an entirety of the deceleration period of the electric motor to prevent any flow of a BEMF current into the power supply, and the electric motor is connected to a power return during a segment or an entirety of the deceleration period of the electric motor to dissipate any BEMF voltage within the electric motor.

Abstract: An apparatus for controlling an electric motor is provided. A plurality of switches is provided for controlling a direction of current through motor coils of the electric motor. A brushless motor control circuit is connected to each of the plurality of switches. Responsive to a request to adjust one of an angular velocity and an angular acceleration of the electric motor, the plurality of switches are activated to place the motor coils in a predetermined configuration to maximize torque or reduce a total back electromotive force (BEMF) from the motor coils.

Abstract: In one embodiment, a tape read/write head supported by a lever is biased in a first position, using magnetic attraction between a magnet supported by the lever, and a return path structure of magnetically permeable material. In the illustrated embodiment, the magnet centers itself, in the absence of a coil generated magnetic field, in the middle of a gap of the magnetic return path structure. In one aspect, the mass of the read/write head and one side of the lever may be balanced by the mass of the magnet and the other side of the lever. The lever and hence the tape read/write head carried by the lever, may be pivoted by conducting current through a coil to generate a magnetic field which is conducted by the return path structure to interact with the magnetic field of the magnet. As a consequence, the lever pivots on a pivot axis as a function of the magnitude and direction of the current through the coil.

Abstract: A tape drive system which includes the ability to reliably reproduce LPOS information even if both of the servo channels of the tape drive system could not detect the LPOS information due to defects. The system recognizes that an LPOS sequence is sequentially incremented by one if a tape is moving in a forward direction and decremented by one if the tape is moving in a backward direction. This sequential property of the LPOS information lends itself to LPOS prediction, where the LPOS prediction is the previous LPOS value plus one if the tape is moving forward and the previous LPOS value minus one if the tape is moving backward. Even if the LPOS words from the two servo channels are both bad, but not all of the bits in the LPOS word are bad. The system uses the remaining good bits from the two servo channels to verify all of the bits of the LPOS prediction word.

Abstract: A method to decode linear position (“LPOS”) information encoded in a sequential information storage medium, by detecting each of one or a plurality of sequential first LPOS servo patterns encoded in a first servo band using a first servo sensor in communication with a first servo channel. While detecting that one or a plurality of first LPOS servo patterns, the method fails to detect (n) second LPOS servo patterns encoded in a second servo band. The method determines a value for (n), and then syncs the first servo channel with the second servo channel using that value of (n).

Abstract: An apparatus, system, and method are disclosed for a tape drive head. An upper servo element reads an upper servo track conforming to a specified format. A lower servo element reads a lower servo track conforming to the specified format. A mid servo element reads a mid servo track. The mid servo element is disposed between the upper servo element and the lower servo element. Sixteen legacy read elements are disposed between the upper server element and the lower servo element. The legacy read elements read legacy data tracks conforming to the specified format. At least eight incremental read elements are interleaved between the legacy read elements. One incremental read element is adjacent to each legacy read element on a side of the legacy read element away from the mid servo element.

Abstract: Dynamic calibration of a secondary velocity signal is provided in a tape drive. In one example, a reel motor is operated to drive a reel carrying a tape in a tape drive. The motion of the tape is measured to provide a measured primary velocity signal of the tape, and in addition, the operation of the reel motor is measured to provide an estimated secondary velocity signal of the tape as a function of motor parameters and the motor operation measurements. The estimated secondary velocity signal of the tape may be calibrated as the tape is driven, as a function of the tape motion measurements and the motor operation measurements. Other embodiments are described and claimed.

Abstract: In one embodiment, a tape movement constraint for a tape drive system, comprises a tiltable tape roller bearing having a grooved surface adapted to contact and engage a surface of the tape as the roller barrel rotates, and an actuator adapted to pivot the roller bearing surface when the actuator is actuated, to control the lateral position of a tape. In operation, in one embodiment, a roller barrel of the tiltable roller bearing is biased in a first position on a pivot axis, using magnetic attraction between a movable magnet and a return path structure of magnetically permeable material. The roller barrel is pivoted on the pivot axis by conducting current through a fixed coil to generate a magnetic field which is conducted by the return path structure to interact with the magnetic field of the magnet. At least a portion of any air bearing between the moving tape and the barrel surface is quenched using grooves formed in the barrel surface.

Abstract: In one embodiment, a tape read/write head supported by a lever is biased in a first position, using magnetic attraction between a magnet supported by the lever, and a return path structure of magnetically permeable material. In the illustrated embodiment, the magnet centers itself, in the absence of a coil generated magnetic field, in the middle of a gap of the magnetic return path structure. In one aspect, the mass of the read/write head and one side of the lever may be balanced by the mass of the magnet and the other side of the lever. The lever and hence the tape read/write head carried by the lever, may be pivoted by conducting current through a coil to generate a magnetic field which is conducted by the return path structure to interact with the magnetic field of the magnet. As a consequence, the lever pivots on a pivot axis as a function of the magnitude and direction of the current through the coil.