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EP0223611A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Method for mapping around defective sectors in a disc drive

Assignee: Seagate Technology LLC
•
Filing: 1986-11-19
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Granted: —
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Expires: 2006-11-19
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Abstract

Abstract Method and apparatus are provided for mapping around defective sectors in a disc drive (12, 25) wherein two outer tracks of the disc in a region beyond the defined track 0 are used to store the drive operating microprogram, and/or manufacturing test program and/or specific mechanical parameters and media defect information. This information can be read from these outer tracks of the disc during initialization of the disc drive, or during seek operations of the drive. It allows the disc drive to react to microprogram problems without changing either a mask ROM or an EPROM. Specifically, the defect list is stored as supplied by the manufacturer on the outer track of the drive. It is merged with the user supplied defect during formatting and used during formatting to flag defective sectors. During initialization of the disc drive, the defect list is loaded into a section of dynamic memory so that it is quickly accessible during seeking of a particular address. Thus, when a seek command is received, the defect list can be accessed, and the positioning command is modified to avoid accessing of a defective block, instead directly accessing the next fully effective block.

Inventors

  • 👤 Don Michael Robinson
  • 👤 Henry Elwood Davenport

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-31 22:45
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/06; G06F3/0601; G11; G11B; G11B20/00; G11B20/10; G11B20/18; G11B20/1883; G11B2020/10916; G11B2220/00; G11B2220/20

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 87 words
In a disc drive with at least one disc, a transducer for reading and writing data on said disc, and meaas for positioning said transducer relative to said disc, said positioning means being responsive to position seek commands to position said head relative to said disc, the improvement comprising means for storing a list of defective tracks and blocks on tracks of said disc, means for accessing said defect list and means for modifying said positioning commands by said stored defect list to avoid accessing defective tracks.
Claim 2
Dependent Claim 87 words
In a disc drive with at least one disc, a transducer for reading and writing data on said disc, and meaas for positioning said transducer relative to said disc, said positioning means being responsive to position seek commands to position said head relative to said disc, the improvement comprising means for storing a list of defective tracks and blocks on tracks of said disc, means for accessing said defect list and means for modifying said positioning commands by said stored defect list to avoid accessing defective tracks.
Claim 3
Dependent Claim 21 words
A disc drive as in Claim 1 wherein said defect list is stored on normally unused tracks of said disc drive.
Claim 4
Dependent Claim 55 words
A disc drive as in Claim 2 wherein each of said positioning commands comprises a logical block address, said positioning means comprising means for modifying said logical block address to a cylinder, head and sector address, said modifying means including means for adjusting said cylinder head and sector address in response to said defect list.
Claim 5
Independent Claim 99 words
A method of adjusting for defective sectors in a disc drive comprising at least one disc having a plurality of data storage tracks wherein each disc storage sector on said disc is uniquely addressed by cylinder, head and sector number, comprising the steps of storing a list of defective sectors on a track of said disc, receiving a logical block address for a block to be accessed, converting said logical block address to a cylinder, head and sector, accessing said defect list, modifying said cylinder, head and sector address according to said defect list, and seeking said modified address.
Claim 6
Independent Claim 99 words
A method of adjusting for defective sectors in a disc drive comprising at least one disc having a plurality of data storage tracks wherein each disc storage sector on said disc is uniquely addressed by cylinder, head and sector number, comprising the steps of storing a list of defective sectors on a track of said disc, receiving a logical block address for a block to be accessed, converting said logical block address to a cylinder, head and sector, accessing said defect list, modifying said cylinder, head and sector address according to said defect list, and seeking said modified address.
Claim 7
Dependent Claim 20 words
A method as claimed in Claim 4 including the step of storing said defects on unused tracks of said disc.
Claim 8
Dependent Claim 28 words
A method as claimed in Claim 5 including the step of transferring the stored defect list from said disc track to controller accessible ROM in said disc drive.
Claim 9
Dependent Claim 26 words
A method as claimed in Claim 5 including the step of storing said defect list on a disc drive track in a cylinder, head, sector format.

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