GB1323299A - Data recording methods and apparatus - Google Patents

Data recording methods and apparatus

Info

Publication number
GB1323299A
GB1323299A GB1323299DA GB1323299A GB 1323299 A GB1323299 A GB 1323299A GB 1323299D A GB1323299D A GB 1323299DA GB 1323299 A GB1323299 A GB 1323299A
Authority
GB
United Kingdom
Prior art keywords
data
bit period
transition
bit
represented
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
British Aircraft Corp Ltd
Original Assignee
British Aircraft Corp Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by British Aircraft Corp Ltd filed Critical British Aircraft Corp Ltd
Publication of GB1323299A publication Critical patent/GB1323299A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/14—Digital recording or reproducing using self-clocking codes
    • G11B20/1403—Digital recording or reproducing using self-clocking codes characterised by the use of two levels
    • G11B20/1423—Code representation depending on subsequent bits, e.g. delay modulation, double density code, Miller code

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Signal Processing For Digital Recording And Reproducing (AREA)

Abstract

1323299 Encoding/decoding digital data BRITISH AIRCRAFT CORP Ltd 19 April 1971 [16 March 1970] 12439/70 Heading G4C Binary data existing in successive bit periods is encoded so that a change of state at the end of a bit period is represented as a transition at the centre of the succeeding bit period and no change of state at the end of a bit period is represented by a transition at the end of the same bit period except when a transition has occurred half way through that bit period due to the preceding data bit when it is represented by no transition. The data so encoded may then be recorded on, e.g., magnetic tape. The encoder comprises a pair of series connected, clocked flip-flops which store a pair of adjacent data bits A and R and a logic circuit arranged to generate signals S and T in successive halves of the bit period corresponding to the second stored datum R in accordance with the logical equations: A logic circuit is also provided for decoding the data read from the tape. The data on the tape is preceded by a code sequence identifying the first recorded digit since the code is purely relative, i.e. complementary sequences encode as the same sequence.
GB1323299D 1970-03-16 1970-03-16 Data recording methods and apparatus Expired GB1323299A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1243970 1970-03-16

Publications (1)

Publication Number Publication Date
GB1323299A true GB1323299A (en) 1973-07-11

Family

ID=10004633

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1323299D Expired GB1323299A (en) 1970-03-16 1970-03-16 Data recording methods and apparatus

Country Status (1)

Country Link
GB (1) GB1323299A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2408247A1 (en) * 1977-11-04 1979-06-01 Mca Disco Vision METHOD AND DEVICE FOR TRANSMISSION AND RECORDING OF A DIGITAL DATA SIGNAL
FR2484739A1 (en) * 1980-06-16 1981-12-18 Philips Nv METHOD FOR ENCODING DATA BITS ON A RECORDING CARRIER, DEVICE FOR PERFORMING THE METHOD, AND RECORDING CARRIER PROVIDED WITH AN INFORMATION STRUCTURE
FR2484738A1 (en) * 1980-06-16 1981-12-18 Philips Nv METHOD FOR ENCODING DATA BITS ON A RECORDING CARRIER, DEVICE FOR IMPLEMENTING THE METHOD, RECORDING CARRIER PROVIDED WITH AN INFORMATION STRUCTURE, AND DEVICE FOR DECODING THE LU SIGNAL ON THE RECORDER CARRIER

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2408247A1 (en) * 1977-11-04 1979-06-01 Mca Disco Vision METHOD AND DEVICE FOR TRANSMISSION AND RECORDING OF A DIGITAL DATA SIGNAL
FR2484739A1 (en) * 1980-06-16 1981-12-18 Philips Nv METHOD FOR ENCODING DATA BITS ON A RECORDING CARRIER, DEVICE FOR PERFORMING THE METHOD, AND RECORDING CARRIER PROVIDED WITH AN INFORMATION STRUCTURE
FR2484738A1 (en) * 1980-06-16 1981-12-18 Philips Nv METHOD FOR ENCODING DATA BITS ON A RECORDING CARRIER, DEVICE FOR IMPLEMENTING THE METHOD, RECORDING CARRIER PROVIDED WITH AN INFORMATION STRUCTURE, AND DEVICE FOR DECODING THE LU SIGNAL ON THE RECORDER CARRIER

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees