EP0323890A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Data storage method
Assignee: Hewlett Packard Ltd
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Filing: 1989-01-04
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Granted: —
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Expires: 2009-01-04
Abstract
Abstract A data storage method is disclosed for storing user data and segmentation information (47) received from a host onto tape. In addition to writing data words and segmentation data relating to record marks (REC) and file marks (FM), the method provides for the writing of further segmentation information concerning 'save set' marks (SSM) that serve to group the data records into sets that are distinct from the collections of records delimited by file marks. In one embodiment, the data words are stored in fixed-size blocks (39) with segmentation data being recorded in an index (40) that terminates each block. Preferably, file marks (FM) and save set marks (SSM) can be independently written to indicate segmentation after the same record. Furthermore a count of save set marks can advantageously be used to facilitate searching of the tape.
Inventors
- 👤 Bruce Allen Thompson
- 👤 Shinya Ozaki
- 👤 Masaki Yamada
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 23:15
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G06; G06F; G06F3/00; G06F3/06; G06F3/0601; G11B15/00; G11B15/02; G11B15/026; G11B20/12; G11B27/00; G11B27/10; G11B27/102; G11B27/107; G11B27/19; G11B27/28; G11B27/30; G11B27/3027; G11B27/3063; G11B27/309; G11B27/32; G11B27/327; G11B27/328; G06F3/0668; G06F3/0671; G06F3/0673; G06F3/0682; G11B2220/00; G11B2220/90; G11B2220/91; G11B2220/913
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
177 words
A data storage method for storing user data and segmentation information on tape, the method including the steps of: - receiving a stream of user-data words organised into a plurality records (R1 to R9) and writing the user-data words to tape (10) together with first segmentation indications (2) indicative of the division of the user-data words into records, and - receiving segmentation signals (FM) representative of a segmentation of the records (R1 to R9) into collections of records and writing second segmentation indications (1) to tape that are indicative of the segmentation represented by said signals, characterised in that the method further comprises the step of: - receiving further segmentation signals (SSM) representative of a further segmentation of said records (R1 to R9) into sets of records distinct from said collections and writing third segmentation indications (6) to tape that are indicative of the further segmentation represented by said further signals, said first, second and third segmentation indications (2,1,6) being written in such a manner as to be distinguishable from one another and said user data words.
Claim 2
Dependent Claim
177 words
A data storage method for storing user data and segmentation information on tape, the method including the steps of: - receiving a stream of user-data words organised into a plurality records (R1 to R9) and writing the user-data words to tape (10) together with first segmentation indications (2) indicative of the division of the user-data words into records, and - receiving segmentation signals (FM) representative of a segmentation of the records (R1 to R9) into collections of records and writing second segmentation indications (1) to tape that are indicative of the segmentation represented by said signals, characterised in that the method further comprises the step of: - receiving further segmentation signals (SSM) representative of a further segmentation of said records (R1 to R9) into sets of records distinct from said collections and writing third segmentation indications (6) to tape that are indicative of the further segmentation represented by said further signals, said first, second and third segmentation indications (2,1,6) being written in such a manner as to be distinguishable from one another and said user data words.
Claim 3
Dependent Claim
46 words
A method according to claim 1, wherein said second and third segmentation indications (1,6) can be independently written to indicate segmentation after the same record whereby said third indications (6) can be used to indicate sets independently of said second indications (1) used to indicate collections.
Claim 4
Dependent Claim
46 words
A method according to claim 1, wherein said third segmentation indications (6) can only be written to indicate segmentation between records at locations represented by said first- mentioned segmentation signals whereby each said set defined by said third segmentation indications comprises one or more said collections.
Claim 5
Independent Claim
49 words
A method according to any one of the preceding claims, wherein said stream of user data words are written in sequence to tape and said first, second and third segmentation indications (2,1,6) are written in locations in the sequence of user data words corresponding to the segmentation they represent.
Claim 6
Independent Claim
46 words
A method according to any one of claims 1 to 3, wherein said user data words are written to tape in blocks (3;39) independently of the record structure of the data words, each block having an associated index (4;40)containing said first, second and third segmentation indications.
Claim 7
Dependent Claim
96 words
A method according to claim 5 wherein a helical scan recording technique is employed to write a plurality of oblique tracks (20,21) each including a main data area (25) and a sub data area (23), said main data area (25) being used to store the blocks (39) of user data words and their associated indexes (40) that contain the segmentation indications, the method including the further steps of accumulating a count (SSC) indicative of the number of third segmentations indications written on the tape, and recording values of said count in said sub data areas (23).
Claim 8
Dependent Claim
52 words
A method according to claim 6, wherein each block (39) and its associated index (40) occupies a predetermined number of tracks, the value of said count (SSC) recorded in the sub data areas (23) of these tracks being that accumulated up to the end of the index (40) of the block (39).
Claim 9
Independent Claim
49 words
A method of retrieving from tape data stored on the tape in accordance with a data storage method as set out in any one of the preceding claims, the method of retrieving data including the step of carrying out a search of the tape utilising said third segmentation indications.
Claim 10
Dependent Claim
51 words
A method of retrieving from tape data stored on the tape in accordance with the data storage method of claim 6 or 7, the method of retrieving data including the step of carrying out a search of the tape utilising said count values (SSC) stored in the sub data areas (23).
References Cited (Backward Citations)
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