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:
May. 01, 1979
Filed:
Sep. 21, 1977
Gerard Democrate, Plaisir, FR;
Claude Cardot, Eaubonne, FR;
Jacques Droux, Montfermeil, FR;
Andre Oisel, Elancourt, FR;
Abstract
A magnetic recording disc includes a plurality of sectors, each of which includes a plurality of data tracks and a reference zone containing information for identifying the data tracks. Some of the sectors are standby sectors containing information which would normally be contained in the sectors containing the data tracks. The reference zones of all sectors contain binary fault indicating bits which indicate whether a particular sector contains faults, and parity bits having values dependent on the location of the parity bit and the value of the fault bit at the same location as the parity bit. A data processor commands a read out head for the disc to be located at a particular position. From the command position of the data processor and the value of the fault bit, the data processor computes an expected parity bit value. The expected parity bit value is compared with the parity bit value read from the disc to provide an indication as to whether the fault bit is accurate.