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    2.
    发明专利
    未知

    公开(公告)号：DE68920523D1

    公开(公告)日：1995-02-23

    申请号：DE68920523

    申请日：1989-08-24

    Applicant: IBM

    Inventor： EGGENBERGER JOHN SCOTT ,  HODGES PAUL ,  PATEL ARVIND MOTIBHAI

    IPC: G06F11/10 ,  G11B20/18 ,  H03M13/00

    Abstract: A method is disclosed for correcting multibyte errors in a magnetic medium on which data is recorded in variable length blocks that comprise sub-blocks of data bytes and corresponding check bytes and include error correction code (ECC) for which ECC syndromes are generated during reading. A sequence of N sequential parity check bytes is written at the end of each block. After ECC syndromes are generated during reading, parity syndromes are generated by comparing parity check bytes computed from data bytes and check bytes as read with the parity check bytes as written. When a long-burst error occurs, a pointer points to the first of the N consecutive bytes in a block that could have been influenced by the error burst. After correcting correctable errors in all sub-blocks not affected by the N bytes identified by the pointer, and adjusting the parity syndromes for errors thus corrected, the adjusted parity syndromes are used to correct the errors in the N bytes indicated by the pointer. Unused ECC syndromes are then adjusted for errors corrected by the adjusted parity syndromes and used to correct all correctable errors then remaining.

    3.
    发明专利
    未知

    公开(公告)号：BR8701783A

    公开(公告)日：1988-02-02

    申请号：BR8701783

    申请日：1987-04-14

    Applicant: IBM

    Inventor： EGGENBERGER JOHN SCOTT ,  PATEL ARVIND MOTIBHAI

    IPC: H03M1/22 ,  H03M5/14 ,  H03M7/14 ,  H03K13/24

    Abstract: Methods and apparatus for implementing PRML codes are disclosed. Specifically considered in detail are rate 8/9, constrained codes having run length limitation parameters (0, 4/4) and (0, 3/6) are provided for any partial response (PR) signalling system employing maximum likelihood (ML) detection.

    4.
    发明专利
    未知

    公开(公告)号：DE2508706A1

    公开(公告)日：1975-11-20

    申请号：DE2508706

    申请日：1975-02-28

    Applicant: IBM

    Inventor： EGGENBERGER JOHN SCOTT ,  HODGES PAUL

    IPC: H03M7/14 ,  G06F5/00 ,  G11B20/14 ,  H03M7/00 ,  H03M7/30 ,  H03M7/40 ,  H03M7/46 ,  H04L23/00 ,  H04L25/49 ,  H03K13/00

    Abstract: Apparatus for converting binary digital data from one form to another according to a variable word length code of fixed rate comprises word position indicating circuitry for indicating predetermined word position states of data in a data storage unit and conversion circuitry for sequentially converting a constant number of input bits at a time into the corresponding number of bits in said other form in dependence upon the contents of the data storage unit and the word position indication. The constant number of bits is less than the number of bits in the longest variable length word in the input data code form. The word position indicating circuitry either generates an updated function representing the current position of the word boundary in the data storage unit or recognizes the boundary from distinctive word ending patterns in the data storage unit.

    5.
    发明专利
    未知

    公开(公告)号：BR8904735A

    公开(公告)日：1990-05-01

    申请号：BR8904735

    申请日：1989-09-20

    Applicant: IBM

    Inventor： EGGENBERGER JOHN SCOTT ,  HODGES PAUL ,  PATEL ARVIND MOTIBHAI

    IPC: G06F11/10 ,  G11B20/18 ,  H03M13/00

    Abstract: A method is disclosed for correcting multibyte errors in a magnetic medium on which data is recorded in variable length blocks that comprise sub-blocks of data bytes and corresponding check bytes and include error correction code (ECC) for which ECC syndromes are generated during reading. A sequence of N sequential parity check bytes is written at the end of each block. After ECC syndromes are generated during reading, parity syndromes are generated by comparing parity check bytes computed from data bytes and check bytes as read with the parity check bytes as written. When a long-burst error occurs, a pointer points to the first of the N consecutive bytes in a block that could have been influenced by the error burst. After correcting correctable errors in all sub-blocks not affected by the N bytes identified by the pointer, and adjusting the parity syndromes for errors thus corrected, the adjusted parity syndromes are used to correct the errors in the N bytes indicated by the pointer. Unused ECC syndromes are then adjusted for errors corrected by the adjusted parity syndromes and used to correct all correctable errors then remaining.

    8.
    发明专利
    未知

    公开(公告)号：DE68920523T2

    公开(公告)日：1995-07-20

    申请号：DE68920523

    申请日：1989-08-24

    Applicant: IBM

    Inventor： EGGENBERGER JOHN SCOTT ,  HODGES PAUL ,  PATEL ARVIND MOTIBHAI

    IPC: G06F11/10 ,  G11B20/18 ,  H03M13/00

    Abstract: A method is disclosed for correcting multibyte errors in a magnetic medium on which data is recorded in variable length blocks that comprise sub-blocks of data bytes and corresponding check bytes and include error correction code (ECC) for which ECC syndromes are generated during reading. A sequence of N sequential parity check bytes is written at the end of each block. After ECC syndromes are generated during reading, parity syndromes are generated by comparing parity check bytes computed from data bytes and check bytes as read with the parity check bytes as written. When a long-burst error occurs, a pointer points to the first of the N consecutive bytes in a block that could have been influenced by the error burst. After correcting correctable errors in all sub-blocks not affected by the N bytes identified by the pointer, and adjusting the parity syndromes for errors thus corrected, the adjusted parity syndromes are used to correct the errors in the N bytes indicated by the pointer. Unused ECC syndromes are then adjusted for errors corrected by the adjusted parity syndromes and used to correct all correctable errors then remaining.

    METHOD AND SYSTEM FOR CORRECTING LONG BURSTS OF CONSECUTIVE ERRORS
    9.
    发明专利
    METHOD AND SYSTEM FOR CORRECTING LONG BURSTS OF CONSECUTIVE ERRORS 未知

    公开(公告)号：AU616788B2

    公开(公告)日：1991-11-07

    申请号：AU3928289

    申请日：1989-08-03

    Applicant: IBM

    Inventor： PATEL ARVIND MOTIBHAI ,  HODGES PAUL ,  EGGENBERGER JOHN SCOTT

    IPC: G06F11/10 ,  G11B20/18 ,  H03M13/00

    Abstract: A method is disclosed for correcting multibyte errors in a magnetic medium on which data is recorded in variable length blocks that comprise sub-blocks of data bytes and corresponding check bytes and include error correction code (ECC) for which ECC syndromes are generated during reading. A sequence of N sequential parity check bytes is written at the end of each block. After ECC syndromes are generated during reading, parity syndromes are generated by comparing parity check bytes computed from data bytes and check bytes as read with the parity check bytes as written. When a long-burst error occurs, a pointer points to the first of the N consecutive bytes in a block that could have been influenced by the error burst. After correcting correctable errors in all sub-blocks not affected by the N bytes identified by the pointer, and adjusting the parity syndromes for errors thus corrected, the adjusted parity syndromes are used to correct the errors in the N bytes indicated by the pointer. Unused ECC syndromes are then adjusted for errors corrected by the adjusted parity syndromes and used to correct all correctable errors then remaining.

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