Track access control system for magnetic disk apparatus
US4893201A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 1988 |
| Grant date | Jan 9, 1990 |
| Priority date | — |
| Expiry date | Jun 6, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/5547
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An improved track access control system for a magnetic disk apparatus connectable to a variety of host controllers without any change thereto, and capable of an offset correction. A control unit in the disk apparatus controlling a moving unit to access a magnetic head at a desired track on the magnetic disk in response to a seek command from a host controller and using an offset correction value which is previously obtained by accessing the magnetic head at a track storing the fine positioning information, and carrying out an offset correction, includes a timer to which a time to be offset-updated within a predetermined timing is set. The control unit makes an offset correction value invalid in response to the time out of the timer, and when a seek command from the host controller in response to the offset invalidity is issued within a predetermined time, the control unit carries out an offset correction in response to the seek command, and executes the seek command, or inhibits an output of an index signal, carries out an offset correction at a previously given track from the host controller, and thereafter, permits an output of the index signal. The control unit sets the time for…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.