Method and apparatus for updating optical memory disc
US4682318A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 16, 1985 |
| Grant date | Jul 21, 1987 |
| Priority date | — |
| Expiry date | Oct 16, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/218
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of updating an optical memory disc, the disc being of the type that has a plurality of zones, one of the zones containing at least one directory block that includes a plurality of entries in the form of addresses which point at data. The method comprising the steps of reading the entries of the one directory block into a temporary location; altering the entries of the one directory block with new directory information; dividing the entries of the one directory block into two new directory blocks, each of the new directory blocks being designated by a separate pointer; writing the two new directory blocks from the temporary location onto the optical memory disc; and storing the pointers in a new directory pointer block of the optical memory disc, whereby subsequent addition of new directory information requires the alteration of less than all of the directory blocks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.