Abstract: A storage device in which file data is divided into multiple blocks for storage on a recording medium. The storage device includes an additional data storing section for storing additional data to be recorded on the recording medium in association with the data to be written, a position determining section for determining recording positions on the recording medium where the blocks should be respectively written, based on the additional data, and a block writing section for writing the respective blocks on the recording positions on the recording medium determined by the recording position determining section. The additional data thus defines a gap length between blocks of recorded data. During a read operation, if the gap length does not comport with the additional data, then an error is assumed.

Abstract: A linear tape data storage device comprises a read head and a write head; a tape transport mechanism for transporting the linear tape data storage medium across the read head and the write head, the device being operated according to a predefined tape format; a DRAM buffer memory for storing data received during a write or a read operation; and error protection means configured to protect said data from soft errors generated by said buffer memory wherein the protection means comprises means for checking parity generated within the tape format itself. In the preferred embodiment the tape format used is the Linear Tape Open (LTO) format.

Abstract: Data from a host computer is buffered, transferred to a logical formatter, compressed and converted to a format suitable for storage on a magnetic tape before being arranged and written sequentially into a main buffer where parity bytes are added as each row of a dataset is written. A physical formatter takes the data sequentially from the main buffer and writes them as codeword quadsets in plural tape tracks. A determination of whether each codeword quadset is acceptably recorded is made by evaluating each codeword quadset for header and codeword quadset pair errors and combining the evaluations.

Abstract: A method, computer program product, and data processing system for recovering corrupted data in a multi-track storage medium, such as magnetic tape, using a Reed-Solomon or other similar error correcting code system, is disclosed. A correction history keeping a tally of actual corrected instances of corruption in the storage medium is established. The “N” tracks requiring the greatest number of actual error corrections are designated as erasures. Any errors in the remaining tracks must be found on an individual basis before being corrected.

Abstract: Data transferred from a host system to magnetic tape storage are divided into blocks that are converted, written to storage and read. An error checker determines whether errors in each block exceed a predetermined number. The result is output with corresponding header identifying information. Information, including header identifying information corresponding to each block written to storage, is stored in a history store. Header identifying information output by the error checker is compared with the header identifying information to identify the data block relating to the error checking output. The marked data block associated with the matching header identifying information is indicated as being good or bad according to the error checker. Selected parts of the header identifying information are masked to compare only the remaining portion of the information with the corresponding history store information.

Abstract: A method of determining error values including loading an error correction code (ECC) entity having rows representing data symbols, determining an error location for a first row, generating an error syndrome for the first row, determining an erasure constant array from the error location, determining an error location for each of the remaining rows, generating an error syndrome for each of the remaining rows and determining the error values for each of the rows from the corresponding error location and corresponding error syndrome and the constant.

Abstract: Herein disclosed a method and apparatus for recovering user data from a data set comprising a plurality of sub data sets, wherein each data set contains a valid data length information, which is compared with an amount of valid user data collected from the data set prior to a sub data set in which an error occurred.

Abstract: A bidirectional code decoding method and apparatus is presented. It uses a class of Reed-Solomon codes capable of bidirectional decoding, more specifically, those for which a value of L for a Galois Field element &agr;L is chosen as −(R−1)/2 for odd values of R and 2(m−1)−R/2 for even values of R. When the symbols of such codes are received at a decoder in a reverse order (from that in which the symbols are normally received) during a reverse directional read, the decoder produces reverse directional syndromes S˜(−k) and converts the reverse directional syndromes S˜(−k) to syndromes S(k) by multiplying S˜(−k) by &agr;(n−1)k for k=L, L+1, . . . , L+R−1.

Abstract: An error propagation control method and a recording/reproducing device which uses the method in a system which makes use of MDFE are disclosed. In the error propagation control method in accordance with multi-level decision feedback equalization in which the input to the detector is fed back to the input side via the feedback filter and the difference between the input signal and the feedback signal is input to the detector, the error propagation state is detected based on the output of the detector. Based on the error propagation detection result, a predetermined offset is added to the slice level of the detector, DC offset is added to the DC level of the input signal of the detector, or a sign of the tap of the feedback filter is reversed.

Abstract: Write on the fly certification of magnetic media includes detecting the start of a defect. A sequence of defect matrices is written over the defect with a write element in a read-after-write head. Each defect matrix in the sequence is read with a read element in the read-after-write head. A check is made to determine if an error exists in the data read from each defect matrix. The defect is determined to extend through each defect matrix if an error exists in the read data.

Abstract: A linear tape data storage device comprises a read head and a write head; a tape transport mechanism for transporting the linear tape data storage medium across the read head and the write head, the device being operated according to a predefined tape format; a DRAM buffer memory for storing data received during a write or a read operation; and error protection means configured to protect said data from soft errors generated by said buffer memory wherein the protection means comprises means for checking parity generated within the tape format itself. In the preferred embodiment the tape format used is the Linear Tape Open (LTO) format.

Abstract: A system for transferring data from a host computing system 10 to a magnetic tape cartridge 12. Data from the host computing system 10 is buffered in a burst buffer 14 before transfer to a logical formatter 16, where data is compressed and converted to a format suitable for storage on the magnetic tape cartridge 12. The logical formatter 16 arranges the data into ‘datasets. The datasets are written sequentially into a main buffer 24 and, as each row of a dataset is written into the main buffer 24, parity bytes (Reed-Solomon) are added.

Abstract: An apparatus for encoding digital data for storage on a data storage medium includes a non-deterministic randomizer code generator. The randomizer code generator may select different randomizer codes for different portions of the data to be stored. The randomizer code used to randomize a given portion of the data may be stored on the media for use in subsequent data retrieval.

Abstract: A multi-level error correction technique for maintaining data integrity in a data recording/recovery device is presented. Data is stored in buffer packets in a segment of a data buffer before being recorded to a storage medium. Error correction codes are generated over a plurality of instances of a plurality of buffer packet patterns in the segment, and are recorded along with all of the buffer packets onto a storage medium. During data recovery from the storage medium, recovered error correction code packets are used to perform multi-level segment correction on the recovered data packets.

Abstract: A method for logically rejecting previously recorded track residue from magnetic media is presented. A session ID unique to a given recording session is encoded into track packet error check and error correction codes but is not itself actually written to tape. During a data recovery session, a reference session ID for the original recording session is acquired by reconstructing the packet session ID from the first few track packets and verifying that a predetermined number of consecutive track packets have identical packet session IDs. Once the reference packet session ID is acquired, it is preloaded into error detection and correction hardware. When a residue track encoded with a previously recorded session ID is recovered by the tape drive track packet detection circuitry, it is inherently rejected because the error detection and correction hardware detects an error and it is therefore never allowed into the data buffer.

Abstract: An apparatus for encoding digital data for storage on a data storage medium includes a non-deterministic randomizer code generator. The randomizer code generator may select different randomizer codes for different portions of the data to be stored. The randomizer code used to randomize a given portion of the data may be stored on the media for use in subsequent data retrieval.

Abstract: Data read from a recording medium, such as a CD or DVD, is checked for errors and the errors are corrected in a fast and efficient manner. First, an error detection code (EDC) is appended to the data, which is arranged in matrix form, by performing a predetermined checking arithmetic operation. Then, a first checking operation is performed on the data using the EDC to generate a first sample value. The data is then error corrected in a first direction and a first correction value is generated if an error is detected. A second checking operation is performed in the first direction using the first correction value to generate a second sample value. The first and second sample values are compared and a first check value is generated. The data is then error corrected in a second direction and a second correction value is generated if an error is detected. A third checking operation is performed in the first direction using the second correction value to generate a third sample value.

Abstract: An apparatus for encoding digital data for storage on a data storage medium includes a non-deterministic randomizer code generator. The randomizer code generator may select different randomizer codes for different portions of the data to be stored. The randomizer code used to randomize a given portion of the data may be stored on the media for use in subsequent data retrieval.

Abstract: A method, apparatus and frame format for allowing the conclusive determination of whether the devices are connected correctly is disclosed. The invention sends a first configuration message to a library manager from a device, the first configuration message including a device address and a serial number associated with the device address, forwards to a control unit from a library manager a second configuration message, the second configuration message including position information for the device and a serial number associated with the device, forwards to the control unit from the device a third configuration message, the third configuration message including position information for the device and a serial number associated with the device and compares at the control unit the second and third configuration messages to determine whether the device and the library manager are configured correctly.

Abstract: An encoding/decoding system for RAID-6 or multiple track tape systems uses one of a selected set of values for m, with m+1 prime and the field GF(2.sup.m) generated by the irreducible polynomial:g(x)=x.sup.m +x.sup.m-1 + . . . +x.sup.2 +x+1.The system performs Galois Field multiplication operations as a combination of cyclic shifting and exclusive-OR operations, and determines multiplicative inverses of weight one, two and three (m+1)-bit symbols by raising various (m+1)-bit symbols to selected powers of two. Using this system, the value of m may be chosen to be as large as or larger than the sector or tape block, and the encoding and decoding is performed once per sector or block.

Abstract: An information transmission system using data compression and/or error detection includes an information compression circuit for compressing digital information to generate compressed information. A record/reproducing device is provided for recording the compressed information on a recording medium, and reproducing the compressed information from the recording medium. Transmission circuitry is provided for transmitting the compressed information reproduced from the record/reproducing device to a transmission channel without expanding the compressed information. An information expansion circuit is then provided for expanding the compressed information which has been transmitted through the transmission channel in order to reproduce the digital information.