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Magneto-Optic Recording Erase Method

IP.com Disclosure Number: IPCOM000062099D
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Bates, KA: AUTHOR [+4]

Abstract

In an erasable magneto-optic data recording medium, such as a flat disk, a strong magnetic field is needed at the medium in order to erase data which has previously been written on the disk. If an area of the disk which is to be used for writing new data already contains old data, this old data must first be erased before the new data can be written in this disk area. When updating a disk's data file, the file is read from the disk, updated, and then stored in random-access memory. In order to now update the disk's data file, the updated data is first written in a new disk sector(s). The disk controller then returns control to the host computer system. However, the disk sector(s) which contain the old file are noted in memory.

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Magneto-Optic Recording Erase Method

In an erasable magneto-optic data recording medium, such as a flat disk, a strong magnetic field is needed at the medium in order to erase data which has previously been written on the disk. If an area of the disk which is to be used for writing new data already contains old data, this old data must first be erased before the new data can be written in this disk area. When updating a disk's data file, the file is read from the disk, updated, and then stored in random-access memory. In order to now update the disk's data file, the updated data is first written in a new disk sector(s). The disk controller then returns control to the host computer system. However, the disk sector(s) which contain the old file are noted in memory. Thereafter, and at the leisure of the host system, the old data file sectors are erased during an idle time of the disk drive. In this way, the data file is quickly updated, and the time needed to erase the old data file is transparent to the user. For example, this function is accomplished on a sector basis by writing the new sector(s) and changing the file pointers to point to the old sector(s). The file pointers are then used later, when erasing the old sector(s).

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