magneto-optical disk

magneto-optical disk

(hardware, storage)
(MO) A plastic or glass disk coated with a compound (often TbFeCo) with special optical, magnetic and thermal properties. The disk is read by bouncing a low-intensity laser off the disk. Originally the laser was infrared, but frequencies up to blue may be possible giving higher storage density. The polarisation of the reflected light depends on the polarity of the stored magnetic field.

To write, a higher intensity laser heats the coating up to its Curie point, allowing its magnetisation to be altered in a way that is retained when it has cooled.

Although optical, they appear as hard drives to the operating system and do not require a special filesystem (they can be formatted as FAT, HPFS, NTFS, etc.).

The initial 5.25" MO drives, introduced at the end of the 1980s, were the size of a full-height 5.25" hard drive (like in IBM PC XT) and the disks looked like a CD-ROM enclosed in an old-style cartridge

In 2006, a 3.5" drive has the size of 1.44 megabyte diskette drive with disks about the size of a regular 1.44MB floppy disc but twice the thickness.

Storage FAQ.
References in periodicals archive ?
for Windows, which utilizes unique features in the Universal Disk Format (UDF) that allow a fully rewritable Magneto-Optical disk to become a permanent archive WORM disk.
In hardware terms, level one data is kept on the network server, level two data is migrated to a storage device such as a magneto-optical disk (MO) jukebox, and level three data is archived in a tape storage library or removed and stored in a vault.
With a rewriteable magneto-optical disk, data can be recorded on the disk, erased and then replaced with new data; such disks cost about $150 each.
Wal-Mart's system, dubbed Computer-Based Learning (CBL), has one to five computer terminals in each store, with CD-ROM and magneto-optical disk drives.
File storage can be RAID, Magneto-Optical disk and DLT tape libraries.
It supports most SCSI storage devices such as Zip(R), Jaz(R), Syquest(R), Magneto-Optical disk drives, CD-R/CD-RWs and external SCSI hard drives.
and Fujitsu for the design-in of a TI signal processor chip for Fujitsu's Magneto-Optical disk (INSEC President's Award).
Users can store studies on magneto-optical disk or transfer them via the new HP integrated digital interface.
to effect a comprehensive redesign of Fujitsu's DynaMO 640SE 640MB Magneto-Optical Disk Drive.
Komag's magneto-optical disk products are made in the United States, are certified, and come with a lifetime limited warranty.
With rewrite cycles of over 6 million passes, the new magneto-optical disk offers better performance and is more reliable than phase change or dye polymer rewritable disks.
The Orray is truly a revolutionary new product which uses multiple heads and multiple platters, like hard disk drives, to achieve greater speeds and capacity; and removable media, like magneto-optical disk drives, for reliability and unlimited storage," said Scott Blum, executive vice president.

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