公开(公告)号：FR2363830A1

公开(公告)日：1978-03-31

申请号：FR7724680

申请日：1977-08-01

Applicant: IBM

Inventor： ARNOLD RICHARD F ,  DISHON YITZHAK ,  OUCHI NORMAN K ,  SCHOR MARSHALL I

IPC: H03M7/40 ,  H03M7/42 ,  H04L23/00 ,  G06F5/00 ,  H03K13/24

Abstract: In an apparatus for generating variable length codewords c(ai) and c(aj) responsive to corresponding fixed length codewords b(ai) and b(aj), where ai and aj are source alphabet characters, ai epsilon A1 and aj epsilon A2, ambiguity arises whenever any fixed length character to be encoded can instantaneously represent source characters ai and aj drawn from two or more dissimilar alphabets i.e. A1 or A2. This is resolved by the inclusion of a Markov processor in combination with the apparatus. The processor establishes the point in the sequence when transitions occur between fixed length characters in one alphabet to fixed length characters in another alphabet by the message context. The processor includes a map of state and transition paths. This map models certain statistical regularities of runs of fixed code elements and the relative likelihood that an ambiguous fixed code character appearing in a first run belongs to a given alphabet. The processor, starting from an arbitrary initial position, tracks any given run of fixed code characters applied to the encoder in terms of a succession of states and paths.

公开(公告)号：CA1059636A

公开(公告)日：1979-07-31

申请号：CA235775

申请日：1975-09-18

Applicant: IBM

Inventor： OUCHI NORMAN K

IPC: H03M5/14 ,  G06T9/00 ,  G11B20/14 ,  H03M7/14 ,  H03M7/30 ,  H03M7/40 ,  H04L23/00 ,  H04L25/49 ,  H03K13/24 ,  H04L3/00

Abstract: APPARATUS AND METHOD EMPLOYING MODIFIED ZERO MODULATION DATA CODE An apparatus and method of processing data employs a modification of a zero modulation code. The zero modulation code has a waveform that is symmetrical about a zero signal level within narrow defined limits. Each data digit, 1 or 0, is encoded into two NRZI digits. Only five charge states are needed. A relaxed run length limitation allows a (d,k) code of 1,4, where (d) is the lower frequency limit and (k) is the upper frequency limit, the limits defining the range from (d) to (k) inclusive of the number of 0 digits that may intervene between the last digit in a preceding code word and the first digit 1 of the current code word, without violating the frequency and charge constraints. During encoding, only one bit lookahead is needed.

公开(公告)号：CA1106975A

公开(公告)日：1981-08-11

申请号：CA285875

申请日：1977-08-31

Applicant: IBM

Inventor： ARNOLD RICHARD F ,  DISHON YITZHAK ,  OUCHI NORMAN K ,  SCHOR MARSHALL I

IPC: H03M7/40 ,  H03M7/42 ,  H04L23/00 ,  G06F13/06

Abstract: A MARKOV PROCESSOR FOR CONTEXT ENCODING FROM GIVEN CHARACTERS AND FOR CHARACTER DECODING FROM GIVEN CONTEXTS In an apparatus for generating variable length codewords c(ai) and c(aj) responsive to corresponding fixed length codewords b(ai) and b(aj), where ai and aj are source alphabet characters, ai.epsilon.A1 and aj.epsilon.A2,ambiguity arises whenever any fixed length charac-ter to be encoded can instantaneously represent source characters ai and aj drawn from two or more dissimilar alphabets i.e., A1 or A2. This is resolved by the inclusion of a Markov processor in combination with the apparatus. The processor establishes the point in the sequence when transitions occur between fixed length characters in one alphabet to fixed length characters in another alphabet by the message context. The processor includes a map of state and transition paths. This map models certain statistical regularities of runs of fixed code elements and the relative likelihood that an ambiguous fixed code character appearing in a first run belongs to a given alphabet. The processor, starting from an arbitrary initial position, tracks any given run of fixed code characters applied to the encoder in terms of a succession of states and paths. SA9-75-024 -1-

公开(公告)号：FR2290094A1

公开(公告)日：1976-05-28

申请号：FR7529323

申请日：1975-09-19

Applicant: IBM

Inventor： OUCHI NORMAN K

IPC: H03M5/14 ,  G06T9/00 ,  G11B20/14 ,  H03M7/14 ,  H03M7/30 ,  H03M7/40 ,  H04L23/00 ,  H04L25/49 ,  H03K13/24

Abstract: An apparatus for processing data employs a modification of a zero modulation code. The zero modulation code has a waveform that is symmetrical about a zero signal level within narrow defined limits. Each data digit, 1 or 0, is encoded into two NRZI digits. A relaxed run length limitation allows use of a (d,k) code of (1,4), where (d) is the minimum number of 0 digits between 1 digits and (k) is the maximum number of 0 digits between 1 digits, without violating the frequency and charge constraints. Only five charge states and only one bit lookahead is needed in order to encode data in the (1,4) code.

公开(公告)号：CA1332247C

公开(公告)日：1994-10-04

申请号：CA533597

申请日：1987-04-01

Applicant: IBM

Inventor： NG CHAN Y ,  OUCHI NORMAN K ,  WANG DAVID T ,  YU WELLINGTON C

IPC: G11B20/12 ,  G11B27/30

Abstract: ROTATING STORAGE DEVICE TRACK FORMAT EMULATION Disclosed is a method for recording a record that emulates a first recording format, which includes a track reference point, such as an index field, used for determining a position of a record on a track according to the first recording format, on a moving storage device operating according to a second recording format which also includes a track reference point. The invention comprises the steps, responsive to location information generated according to the first recording formats, of: (1) determining an original angular position of a record according to the first recording format; (2) calculating in response to the original angular position and a parameter a preferred angular position for the record according to the second recording format; (3) determining an actual angular position of the record recorded according to the second recording format; and (4) recording an extension of the record to compensate for the difference between the preferred angular position and the actual angular position.

公开(公告)号：CA1105141A

公开(公告)日：1981-07-14

申请号：CA359579

申请日：1980-09-04

Applicant: IBM

Inventor： ARNOLD RICHARD F ,  DISHON YITZHAK ,  OUCHI NORMAN K ,  SCHOR MARSHALL I

IPC: H03K9/08 ,  H03K13/01

Abstract: A MARKOV PROCESSOR FOR CONTEXT ENCODING FROM GIVEN CHARACTERS AND FOR CHARACTER DECODING FROM GIVEN CONTEXTS In an apparatus for generating variable length codewords c(aj) and c(aj) responsive to corresponding fixed length codewords b(ai) and b(aj), where ai and aj are source alphabet characters, ai.epsilon.Al and aj.epsilon.A2, ambiguity arises whenever any fixed length charac-ter to be encoded can instantaneously represent source characters aj and aj drawn from two or more dissimilar alphabets i.e., A1 or A2. This is resolved by the inclusion of a Markov processor in combination with the apparatus. The processor establishes the point in the sequence when transitions occur between fixed length characters in one alphabet to fixed length characters in another alphabet by the message context. The processor includes a map of state and transition paths. This map models certain statistical regularities of runs of fixed code elements and the relative likelihood that an ambiguous fixed code character appearing in a first run belongs to a given alphabet. The processor, starting from an arbitrary initial position, tracks any given run of fixed code characters applied to the encoder in terms of a succession of states and paths. SA9-75-024

公开(公告)号：FR2393367A1

公开(公告)日：1978-12-29

申请号：FR7813280

申请日：1978-04-27

Applicant: IBM

Inventor： OUCHI NORMAN K

IPC: G06F3/06 ,  G06F11/10 ,  G06F12/00 ,  G06F12/16 ,  G11B20/18 ,  G06F13/00