US4914529A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data disk defect handling using relocation ID fields
Assignee: Western Digital Corp
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Filing: 1988-07-18
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Granted: 1990-04-03
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Expires: 2008-07-18
Abstract
Abstract The invention provides a method and format for storing a relocation identification block within the data field of a sector having a defect. The relocation identification block provides an address for a replacement sector to be used for data which cannot be stored in the unusable sector.
Inventors
- 👤 Carl Bonke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:51
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/18; G11B20/1883; G11B2220/00; G11B2220/20
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
110 words
A method for data relocation due to disk media defects comprising providing: an alternate storage sector having an identification field; asserting a bad block bit and a mapped flag bit in the ID field of the defective sector; storing an alternate ID field corresponding to the alternate sector in the data field of the defective sector only if the sector is defective; reading the bad block bit during data transfer; reading the alternate sector ID from the data field; completing data transfer from the current track; seeking to the alternate sector defined by the alternate ID present in the data field; and reading the data stored in the alternate sector.
Claim 2
Independent Claim
110 words
A method for data relocation due to disk media defects comprising providing: an alternate storage sector having an identification field; asserting a bad block bit and a mapped flag bit in the ID field of the defective sector; storing an alternate ID field corresponding to the alternate sector in the data field of the defective sector only if the sector is defective; reading the bad block bit during data transfer; reading the alternate sector ID from the data field; completing data transfer from the current track; seeking to the alternate sector defined by the alternate ID present in the data field; and reading the data stored in the alternate sector.
Claim 3
Dependent Claim
82 words
A record with a data format for sectors of a disk track comprising: a first ID field including a definition byte having a bad block bit and a mapped flag bit; a data field for normal data storage located within the sector defined by the first identification field; a second identification field having identical format with the first identification field, the second identification field stored in the data field of the sector when a media defect is present in the data field.
Claim 4
Dependent Claim
82 words
A record with a data format for sectors of a disk track comprising: a first ID field including a definition byte having a bad block bit and a mapped flag bit; a data field for normal data storage located within the sector defined by the first identification field; a second identification field having identical format with the first identification field, the second identification field stored in the data field of the sector when a media defect is present in the data field.
References Cited (Backward Citations)
JPS5755580A
Cited
US4630140A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-02 | 1993-10-02 | 1994-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-02 | 1997-10-02 | 1998-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-02 | 2001-10-02 | 2002-04-03 | $7700.00 | Window Closed / Lapsed |