The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 19, 1990
Filed:
Dec. 16, 1988
Devon B Worrell, Westminister, CA (US);
William C Caldwell, Fountain Valley, CA (US);
Paul W Hanmann, Anaheim, CA (US);
Robert W Visser, Huntington Beach, CA (US);
Paul R Nitza, Tustin, CA (US);
Emulex Corporation, Costa Mesa, CA (US);
Abstract
A system for managing data errors and media defects on magnetically and optically encoded disks. The invention is a disk controller utilizing a cylinder-based defect management system that reduces the amount of physical media space needed for bad block data replacement blocks. A unique attribute is calculated for and stored with each data block on each track that permits the controller to rapidly determine if a desired data block is in the current track. Spare blocks within a cylinder may be allocated to any track within that cylinder, permitting the system to more efficiently handle larger media or data errors than prior art devices that are limited to a particular number of spare blocks per track. When a bad data block occurs, the data from that block and all subsequent blocks is 'slipped' to succeeding data blocks, thereby preserving the contiguity of the logical data structure and minimizing disk access time. No re-vectoring to replacement data blocks is done until an entire track is replaced, thereby reducing the amount of error-handling time compared to prior art techniques.