Abstract: A flash memory based storage device may utilize magnetoresistive random access memory (MRAM) as at least one of a device memory, a buffer, or high write volume storage. In some embodiments, a processor of the storage device may compare a logical block address of a data file to a plurality of logical block addresses stored in a write frequency file buffer table and causes the data file to be written to the high write volume MRAM when the logical block address of the data file matches at least one of the plurality of logical block addresses stored in the write frequency file buffer table. In other embodiments, upon cessation of power to the storage device, the MRAM buffer stores the data until power is restored, after which the processor causes the buffered data to be written to the flash memory under control of the flash memory controller.

Abstract: A flash memory based storage device may utilize magnetoresistive random access memory (MRAM) as at least one of a device memory, a buffer, or high write volume storage. In some embodiments, a processor of the storage device may compare a logical block address of a data file to a plurality of logical block addresses stored in a write frequency file buffer table and causes the data file to be written to the high write volume MRAM when the logical block address of the data file matches at least one of the plurality of logical block addresses stored in the write frequency file buffer table. In other embodiments, upon cessation of power to the storage device, the MRAM buffer stores the data until power is restored, after which the processor causes the buffered data to be written to the flash memory under control of the flash memory controller.

Abstract: A flash memory based storage device may utilize magnetoresistive random access memory (MRAM) as at least one of a device memory, a buffer, or high write volume storage. In some embodiments, a processor of the storage device may compare a logical block address of a data file to a plurality of logical block addresses stored in a write frequency file buffer table and causes the data file to be written to the high write volume MRAM when the logical block address of the data file matches at least one of the plurality of logical block addresses stored in the write frequency file buffer table. In other embodiments, upon cessation of power to the storage device, the MRAM buffer stores the data until power is restored, after which the processor causes the buffered data to be written to the flash memory under control of the flash memory controller.

Abstract: A flash memory based storage device may utilize magnetoresistive random access memory (MRAM) as at least one of a device memory, a buffer, or high write volume storage. In some embodiments, a processor of the storage device may compare a logical block address of a data file to a plurality of logical block addresses stored in a write frequency file buffer table and causes the data file to be written to the high write volume MRAM when the logical block address of the data file matches at least one of the plurality of logical block addresses stored in the write frequency file buffer table. In other embodiments, upon cessation of power to the storage device, the MRAM buffer stores the data until power is restored, after which the processor causes the buffered data to be written to the flash memory under control of the flash memory controller.

Abstract: The disclosure describes a data storage system that includes a signal defect correction system for removing signal defects in magnetoresistive head playback signals. The signal defect correction system utilizes a matched finite impulse response (FIR) filter and digital signal processing algorithms. The matched FIR filter is designed with an impulse response that is the time reversed, complex conjugate of a signal defect model. The signal defect model is generated from a number of sample playback signals. The matched FIR filter is applied to the playback signal and digital signal processing techniques are applied to the filter response to detect a signal defect in the playback signal and estimate the amplitude and location of the signal defect. The signal defect model is retrieved from memory and applied to the playback signal using the amplitude and location estimates to substantially remove the signal defect from the playback signal.

Abstract: Data storage tape comprises one or more data tracks and a servo band. The servo band stores a plurality of servo patterns within a servo frame to facilitate head positioning relative to the data tracks. Spacings between the servo patterns within the servo frame vary to encode information in the servo frame. A number of bits in the information is greater than a number of servo patterns within the frame. Servo patterns in different servo bands on the data storage tape may be different to provide band identification information. The different servo patterns of the different servo bands may allow lateral position calculations using the same formula for each servo pattern.

Abstract: In general, the invention is directed to servo techniques that utilize servo patterns to facilitate head positioning relative to the data tracks. For example, the servo techniques may include a first series of servo patterns configured to allow calculation of a position error signal that substantially mitigates error resulting from a variation in velocity of the data storage tape during detection of the at least one of the servo patterns in the first series. The servo techniques may also include a second series of servo patterns interleaved within the first series of servo patterns in order to encode data. The encoded data may include linear position information. Embodiments may allow a data storage tape meeting a currently accepted data storage tape specification, e.g., an LTO Ultrium specification, to record data in a higher density than currently implemented with the specification.

Abstract: In general, the invention is directed to servo techniques that utilize servo patterns to facilitate head positioning relative to the data tracks. For example, the servo techniques may include a first series of servo patterns configured to allow calculation of a position error signal that substantially mitigates error resulting from a variation in velocity of the data storage tape during detection of the at least one of the servo patterns in the first series. The servo techniques may also include a second series of servo patterns interleaved within the first series of servo patterns in order to encode data. The encoded data may include linear position information. Embodiments may allow a data storage tape meeting a currently accepted data storage tape specification, e.g., an LTO Ultrium specification, to record data in a higher density than currently implemented with the specification.

Abstract: Data storage tape comprises one or more data tracks and a servo band. The servo band stores a plurality of servo patterns within a servo frame to facilitate head positioning relative to the data tracks. Spacings between the servo patterns within the servo frame vary to encode information in the servo frame. A number of bits in the information is greater than a number of servo patterns within the frame. Servo patterns in different servo bands on the data storage tape may be different to provide band identification information. The different servo patterns of the different servo bands may allow lateral position calculations using the same formula for each servo pattern.

Abstract: The disclosure describes a data storage system that includes a signal defect correction system for removing signal defects in magnetoresistive head playback signals. The signal defect correction system utilizes a matched finite impulse response (FIR) filter and digital signal processing algorithms. The matched FIR filter is designed with an impulse response that is the time reversed, complex conjugate of a signal defect model. The signal defect model is generated from a number of sample playback signals. The matched FIR filter is applied to the playback signal and digital signal processing techniques are applied to the filter response to detect a signal defect in the playback signal and estimate the amplitude and location of the signal defect. The signal defect model is retrieved from memory and applied to the playback signal using the amplitude and location estimates to substantially remove the signal defect from the playback signal.

Abstract: Techniques are described for accurately processing playback signals of time-based servo patterns recorded on a data storage medium. In particular, techniques are described for determining values for signal peaks within a playback signal of a time-based servo pattern by applying interpolation to data points in proximity to each of the signal peaks. At least three data points are identified in proximity to a desired peak to be detected within the playback signal. A value is calculated for the desired peak based on interpolation of the at least three data points. A playback signal of a time-based servo pattern may include a sequence of signal peaks. A time-based servo pattern may be detected based on lengths of time measured between consecutive peaks in the sequence of peaks. A position error signal (PES) may be generated based on the values calculated for each of the sequence of peaks.

Abstract: The invention is directed to servo techniques that make use of sequences of servo marks, rather than individual marks for generation of position error signals. In particular, random or pseudo-random sequences of servo marks may be recorded on the medium in an overlapping fashion. For example, a first sequence of marks and a second sequence of marks may overlap in the servo track. The second sequence may be substantially non-correlated with the first sequence, and may be recorded in an offset location along the track relative to the first sequence. Different correlators can be used to detect the different sequences, and position error signals can be generated based on timings associated with the detection of the first sequence relative to the second sequence.

Abstract: The invention is directed to servo techniques that make use of sequences of servo marks, rather than individual marks for generation of position error signals. In particular, random or pseudo-random sequences of servo marks may be recorded on the medium in an overlapping fashion. For example, a first sequence of marks and a second sequence of marks may overlap in the servo track. The second sequence may be substantially non-correlated with the first sequence, and may be recorded in an offset location along the track relative to the first sequence. Different correlators can be used to detect the different sequences, and position error signals can be generated based on timings associated with the detection of the first sequence relative to the second sequence.

Abstract: The invention provides techniques for verifying that a servo pattern has been properly recorded. For example, the amplitude of a signal corresponding to magnetic servo patterns can be detected and then compared to a threshold to determine whether the servo patterns were properly recorded. The signal strength may be determined for a servo band that includes multiple servo tracks. To enable this determination, a magnetic head may be designed to have sufficient width to enable the head to detect magnetic signal strength corresponding to more than one servo track.

Abstract: A system is described including a data cartridge carrying a non-tape storage medium. The data cartridge includes read/write circuitry to access the non-tape storage medium and an external electrical connector coupled to the controller. The system further includes a tape drive emulator having an electrical socket to receive the electrical connector of the data cartridge. The socket may comprise a zero insertion force (ZIF) socket having a set of connectors that engage the electrical connections of the data cartridge. The tape drive emulator may mechanically actuate the ZIF socket upon sensing the insertion of the electrical interface of the data cartridge. Alternatively, the socket may include a mechanical actuation mechanism operable by a data cartridge library automation system to electrically couple the data cartridge to the emulation tape drive.

Abstract: A servo track recording tape includes a plurality of data tracks and a servo band dedicated for servo information. The servo band includes substantially uniformly written servo carrier information across a predetermined servo carrier width along the length of the tape with at least one encoded track pitch defined therein. Each encoded track pitch has alternating erased and non-erased portions along the length of the tape for defining servo tracks. The alternating erased and non-erased portions of the at least one encoded track pitch include encoded information provided by varying the length of one or more of the erased portions. The encoded information may be representative of tape locations along the length of the tape. The servo band may include two or more encoded track pitches defined in the substantially uniformly written servo carrier information with each encoded track pitch defining corresponding servo tracks.

Abstract: The tape in a data cartridge has a beginning of tape (BOT) zone adjacent a leading end, a load point (LP) zone adjacent the BOT zone, an end of tape (EOT) zone adjacent a trailing end, an early warning (EW) zone adjacent the EOT zone, and a data recording (DR) zone between the LP and EW zones. Servo tracks extending between the BOT and EOT enable the closed-loop servo operation of a tape deck during the recording of data at data flux transition densities within a predetermined range of flux transition densities. A BOT indicator includes a first type magnetic marker extending throughout the BOT zone and has a BOT flux density. An LP indicator includes spaced second type magnetic markers on the servo tracks at the border of the LP and DR zones. An EW indicator which is identical to the LP indicator is located on the servo tracks at the border of the DR and EW zones. An EOT indicator includes a first type marker extending throughout the EOT zone and has an EOT flux density.

Abstract: A physical and logical block search method and apparatus that also locates the end of data on a data tape written in a serpentine pattern. A physical address is decoded to determine the track location and physical block address of a physical block on a serpentine data pattern written on a data cartridge tape. The tape is manipulated in the forward and reverse direction depending on the location of the beginning of data on the track. The search algorithm exploits serpentine nature of the tape and the location of the physical blocks in each track to find the physical address. The logical address of a logical block is used to determine a target track number. A prediction is made as to the location of the target track. The prediction is verified by checking the block. If the logical block was not accurately predicted the method repredicts until the logical block is found. The end of tape is located using a binary search based on knowledge of the track assignment of the serpentine data pattern on the tape.