magneto-optical disk

1 definition found

magneto-optical disk - Free On-line Dictionary of Computing (26 May 2007) :

  magneto-optical disk
  magneto-optical drive
  M O drive
  
     <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  (http://cis.ohio-state.edu/hypertext/faq/usenet/arch-storage/part1/faq.html)
      .
  
     (2006-07-25)