Method of writing information relating to faults in a magnetic recording medium
US4152695A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 1977 |
| Grant date | May 1, 1979 |
| Priority date | — |
| Expiry date | Sep 21, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/20
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.