Abstract: A unidirectional and bi-directional tape head with sub-ambient pressure cavities. The tape head is adapted for reading and/or writing to a magnetic tape. The tape head includes: a tape-bearing surface; a transducer area, having at least one transducer designed for reading and/or writing to the magnetic tape; and a cavity open on the tape-bearing surface adjacent to the transducer area that extends parallel to the transducer area and transversally to the longitudinal direction of circulation of the tape such that an opening of the cavity faces the tape in operation. The cavity is further dimensioned and arranged with respect to the transducer area to create, upon circulation of the tape in operation, sub-ambient pressure therein. The present invention allows for a very close tape-head spacing.

Abstract: In one embodiment, a method includes reading packets of data from M parallel data tracks of a magnetic tape to obtain a plurality of (D+P)-symbol codewords which are logically arranged in nM encoded blocks, each packet including a row of an encoded block, where each encoded block includes an array having rows and columns of code symbols, wherein symbols of each of the (D+P)-symbol codewords are distributed over corresponding rows of the nM encoded blocks, decoding sub-blocks from rows and columns of a plurality of product codewords from the nM encoded blocks, each product codeword including a logical array of code symbols having the rows which include respective row codewords and the columns which include respective column codewords, where each sub-block includes a logical array having rows and columns of data symbols, combining the sub-blocks to form a block of data, and outputting the block of data.

Abstract: A tape head includes a body, which includes a transducer. The transducer may be a read or write element, respectively configured so as for the tape head to read from or write to a tape, in operation. The body exhibits a tape-bearing surface, which is typically configured to face and interact with the tape, in operation. The tape head further includes a closure. The closure is fixed on a leading side or a trailing side of the body and includes a skiving edge vis-à-vis the transducer. The skiving edge is adjoined by non-skiving edges. Finally, the closure has a top surface that meets the skiving edge; the top surface is level with the tape-bearing surface. Also included are related devices; tape head apparatuses for recording and/or reproducing tapes, comprising such tape heads; and methods of fabrication thereof.

Abstract: A mechanical resonator includes a spring-mass system, wherein the spring-mass system comprises a phase-change material. The mechanical resonator typically comprises an electrical circuit portion, coupled to the phase-change material to alter a phase configuration within the phase-change material. Methods of operation are also disclosed.

Abstract: A tape head assembly includes a set of data readers configured to simultaneously read data from a set of adjacent data tracks of a tape storage medium, each data track having a width; wherein the width of each data reader of the set along a lateral extension of the tape head assembly is equal to or less than the width of a data track wherein the lateral extension of the tape head assembly is orthogonal to a longitudinal extension of the tape storage medium when arranged in a tape drive containing the tape head assembly spanning at least the set of data tracks during reading; and a servo reader arrangement containing at least one servo reader arranged laterally offset from one of the data readers by less than the width of a data track.

Abstract: In one embodiment, a system includes a data processing unit configured to read encoded data from a magnetic tape medium. The data processing unit is also configured to decode a plurality of codeword interleaves (CWIs) from the encoded data, each CWI being a row in a sub data set logically organized into a two-dimensional array. The array includes a predetermined number of rows and columns of predetermined lengths. The data processing unit is also configured to determine an address for a first-written CWI without successfully decoding a corresponding codeword interleave designation (CWID) from the encoded data, each CWID specifying an address for a corresponding CWI. Also, each CWID is calculated as a function of a logical track number and a CWI set number.

Abstract: In one embodiment, a method includes computing more than one skew estimate within each timing-based servo (TBS) frame. Each skew estimate is related to an estimated position of a magnetic tape read head in relation to a magnetic tape medium. In another embodiment, a system includes a hardware processor and logic integrated with and/or executable by the hardware processor. The logic is configured to cause the hardware processor to compute an initial skew estimate based on longitudinal position (LPOS) sync-pattern detection flags detected using servo channels which process at least two readback signals, with the proviso that the LPOS sync-pattern detection flags are only used to compute the initial skew estimate. The logic is also configured to compute more than one skew estimate within each TBS frame thereafter, each skew estimate being related to an estimated position of a magnetic tape read head in relation to a magnetic tape medium.

Abstract: In one embodiment, a system includes a data processing unit configured to read encoded data from a magnetic tape medium. The data processing unit is also configured to decode a plurality of codeword interleaves (CWIs) from the encoded data, each CWI being a row in a sub data set logically organized into a two-dimensional array. The array includes a predetermined number of rows and columns of predetermined lengths. The data processing unit is also configured to determine an address for a first-written CWI without successfully decoding a corresponding codeword interleave designation (CWID) from the encoded data, each CWID specifying an address for a corresponding CWI. Also, each CWID is calculated as a function of a logical track number and a CWI set number.

Abstract: In one embodiment, a method includes computing more than one skew estimate within each timing-based servo (TBS) frame. Each skew estimate is related to an estimated position of a magnetic tape read head in relation to a magnetic tape medium. In another embodiment, a system includes a hardware processor and logic integrated with and/or executable by the hardware processor. The logic is configured to cause the hardware processor to compute an initial skew estimate based on longitudinal position (LPOS) sync-pattern detection flags detected using servo channels which process at least two readback signals, with the proviso that the LPOS sync-pattern detection flags are only used to compute the initial skew estimate. The logic is also configured to compute more than one skew estimate within each TBS frame thereafter, each skew estimate being related to an estimated position of a magnetic tape read head in relation to a magnetic tape medium.

Abstract: An apparatus includes a loop filter that receives a plurality of input signals. Each of the input signals is based on a different timing error detector output signal. The apparatus also includes a plurality of read channels, a plurality of interpolation filters, and an array of transducers. Each of the interpolation filters is in communication with a corresponding one of the read channels. Each of the transducers is in communication with a corresponding one of the read channels. The loop filter processes the plurality of input signals, and outputs a different total phase signal for each received input signal. Each of the interpolation filters samples the corresponding read channel based on one of the total phase signals output by the loop filter. The loop filter processes the plurality of input signals by calculating a phase estimate of the samples, and a skew estimate of the samples, relative to written data.

Abstract: A block of data is partitioned into a plurality of sub-blocks each including a logical array having rows and columns of data symbols, encoded using a row linear block code and a column linear block code. Each product codeword includes a logical array of code symbols having rows which include respective row codewords and columns which include respective column codewords. The product codewords are encoded by encoding groups of L symbols, using a rate-L/(L+M) linear block code to produce a plurality of (L+M)-symbol codewords which are logically arranged in nQ encoded blocks (where n is an integer greater than zero). Each of the nQ encoded blocks includes an array having rows and columns of code symbols in which each column includes a codeword of the column code.

Abstract: A block of data is partitioned into a plurality of sub-blocks each including a logical array having rows and columns of data symbols, encoded using a row linear block code and a column linear block code. Each product codeword includes a logical array of code symbols having rows which include respective row codewords and columns which include respective column codewords. The product codewords are encoded by encoding groups of L symbols, using a rate-L/(L+M) linear block code to produce a plurality of (L+M)-symbol codewords which are logically arranged in nQ encoded blocks (where n is an integer greater than zero). Each of the nQ encoded blocks includes an array having rows and columns of code symbols in which each column includes a codeword of the column code.

Abstract: A magnetic tape medium includes at least one servo band along a longitudinal extension of the tape medium which at least one servo band comprises servo patterns organized in servo frames for supporting to determine positional information. At least one of the servo frames includes a first burst comprising at least two servo stripes inclined at a first angle with respect to a direction orthogonal to the longitudinal extension of the tape medium, followed by a second burst including at least two servo stripes inclined at a second angle with respect to a direction orthogonal to the longitudinal extension of the tape medium, which second angle is different from the first angle. At least one of the stripes of the first burst has a first magnetic polarity and at least one of the stripes of the second burst has a second magnetic polarity different from the first magnetic polarity.

Abstract: A mechanical resonator includes a spring-mass system, wherein the spring-mass system comprises a phase-change material. The mechanical resonator typically comprises an electrical circuit portion, coupled to the phase-change material to alter a phase configuration within the phase-change material. Methods of operation are also disclosed.

Abstract: A tape head, configured to contact a magnetic tape, at the level of a contact plane, for writing to the tape, in operation is provided. The tape head includes a transducer, the latter being a write element, configured to write to the magnetic tape, in operation. The transducer includes a layered write pole, the latter comprising a set of two or more superimposed layers of distinct materials, the layers superimposed in a direction perpendicular to the contact plane. A saturation magnetization of each of two material layers of the set is between 1.0 to 2.3 Tesla. A contrast between the saturation magnetizations of the two material layers of the set is between 32% and 130%, the contrast defined as 100×(Bs,max/Bs,min?1), where Bs,max and Bs,min respectively denote a largest one and the smallest one of the saturation magnetizations of the two material layers of the set.

Abstract: Embodiments include methods, systems and computer program products for controlling a lateral position of a tape head of a magnetic tape drive. Aspects include determining a first servo signal by reading position marks from a first servo band on a magnetic tape using a first sensor and determining a second servo signal by reading position marks from a second servo band on the magnetic tape using a second sensor. Aspects also include delaying the first servo signal relative to the second servo signal by a delay and calculating an average signal based on the first and the delayed second servo signal. Aspects further include determining servo information from the average signal indicative of a deviation of the lateral position of the tape head from an ideal lateral position of the tape head and controlling the tape head to adjust its lateral position such that the deviation is decreased.

Abstract: A computer program product is provided for performing symbol timing recovery in a parallel recording channel system. The computer program product comprises a computer readable storage medium having program instructions embodied therewith. The program instructions are executable by a processor to cause the processor to receive a plurality of timing-error estimates for a plurality of read channels. Each of the timing-error estimates corresponds to one of the read channels. Also, the program instructions are executable by the processor to cause the processor to calculate a common phase based on the plurality of timing-error estimates. Moreover, the program instructions are executable by the processor to cause the processor to calculate a skew of a transducer array based on the plurality of timing-error estimates, and to calculate a different total phase estimate for each read channel based on the calculated common phase and the calculated skew of the transducer array.

Abstract: In one embodiment, a data storage system includes a head configured to produce a signal representing data stored on a storage medium, a bank of noise whitening filters configured to apply one or more noise whitening filters to the signal to produce a filtered signal, and a data-dependent noise mean calculator configured to estimate a data-dependent noise mean from the filtered signal. The system also includes a branch metric calculator configured to perform one or more branch metric calculations on the filtered signal to produce one or more branch metrics, the one or more branch metric calculations accounting for the data-dependent noise mean. Moreover, the system includes an adaptive data-dependent noise-predictive maximum likelihood (D3-NPML) detector configured to generate an output stream from the one or more branch metric calculations.

Abstract: An apparatus includes a loop filter that receives a plurality of input signals. Each of the input signals is based on a different timing error detector output signal. The apparatus also includes a plurality of read channels, a plurality of interpolation filters, and an array of transducers. Each of the interpolation filters is in communication with a corresponding one of the read channels. Each of the transducers is in communication with a corresponding one of the read channels. The loop filter processes the plurality of input signals, and outputs a different total phase signal for each received input signal. Each of the interpolation filters samples the corresponding read channel based on one of the total phase signals output by the loop filter. The loop filter processes the plurality of input signals by calculating a phase estimate of the samples, and a skew estimate of the samples, relative to written data.

Abstract: A computer program product is provided for performing symbol timing recovery in a parallel recording channel system. The computer program product comprises a computer readable storage medium having program instructions embodied therewith. The program instructions are executable by a processor to cause the processor to receive a plurality of timing-error estimates for a plurality of read channels. Each of the timing-error estimates corresponds to one of the read channels. Also, the program instructions are executable by the processor to cause the processor to calculate a common phase based on the plurality of timing-error estimates. Moreover, the program instructions are executable by the processor to cause the processor to calculate a skew of a transducer array based on the plurality of timing-error estimates, and to calculate a different total phase estimate for each read channel based on the calculated common phase and the calculated skew of the transducer array.