Method and mechanism to distinguish valid from outdated recording blocks in a tape drive
US6441980B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 2001 |
| Grant date | Aug 27, 2002 |
| Priority date | — |
| Expiry date | Aug 28, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/90
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and a mechanism enabling the method are described to aid in distinguishing new information from old information on a medium. A new variable called a Master Write Pass Count is created for the medium. The Master Write Pass Count is initialized once, advanced on each occasion that new information is written in the medium, and it is never reinitialized or regressed. During each write session the Master Write Pass Count is copied into a Write Pass Count variable associated with each block receiving the new information. The Write Pass Counts may be stored in the header or trailer of the associated block, or external to the block. When the blocks are read from the medium, the Write Pass Counts may be used alone, or in combination with other information associated with the blocks, such as a block identification number, to aid in distinguishing new information from old information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.