hard disk

3 definitions found

hard disk - Collaborative International Dictionary of English v.0.48 :

  magnetic disc \magnetic disc\, magnetic disk \magnetic disk\n.
     A ditical memory device consisting of a flat disk covered
     with a magnetic coating on which information is stored; a
     hard disk, floppy disk, and diskette are typically
     magnetic disks.
  
     Syn: disk, disc.
          [WordNet 1.5]

hard disk - WordNet (r) 2.1 (2005) :

  hard disk
      n 1: a rigid magnetic disk mounted permanently in a drive unit
           [syn: hard disc, hard disk, fixed disk]

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

  hard disk
  floating head
  
     <storage> (In contrast to floppy disk).  One or more rigid
     magnetic disks rotating about a central axle with associated
     read/write heads and electronics, used to store data.  Most
     hard disks are permanently connected to the drive (fixed
     disks) though there are also removable disks.
  
     High speed disks have an access time of 28 milliseconds or
     less, and low-speed disks run 65 milliseconds or more.  The
     higher speed disks also transfer their data faster than the
     slower speed units.
  
     Each surface of each disk is divided into a number of evenly
     spaced concentric circular tracks.  The set of all tracks at
     a given radius on all surfaces (the tracks which can be
     accessed without moving the heads) are known as a cylinder.
     Each track is divided into sectors.
  
     The heads "float" just above the disk's surface on a current
     of air.  As the disk turns it moves the air around it, creaing
     theair current.  The head has an aerodynamic shape so the
     current pushes it away from the disk.  A small spring pushes
     the head towards the disk at the same time keeping the head at
     a constant distance from the disk (about two microns).
  
     Disk drives are commonly characterised by the kind of
     interface used to connect to the computer, e.g. ATA, IDE,
     SCSI.
  
     See also winchester.
  
     Suchanka's PC-DISK library (http://pc-disk.de/).
  
     (2004-06-17)