Maxtor QUICKVIEW ATA - Manual (Page 56)

Glossary
G-2 Maxtor QuickView 400/500GB Serial ATA Hard Disk Drive
CAPACITY – The amount of information
that can be stored on a disk drive. The data is
stored in bytes, and capacity is usually
expressed in megabytes.
CDB – Command Descriptor Block. The
SCSI structure used to communicate requests
from an initiator (system) to a target (drive).
CLEAN ROOM – An environmentally
controlled dust-free assembly or repair
facility in which hard disk drives are
assembled or can be opened for internal
servicing.
CLUSTER – A group of sectors on a disk
drive that is addressed as one logical unit by
the operating system.
CONTROLLER – Short form of disk
controller. The chip or complete circuit that
translates computer data and commands into
CONTROLLER CARD – An adapter
holding the control electronics for one or
more hard disks, usually installed in a slot in
the computer.
CPU – Acronym for Central Processing
Unit. The microprocessor chip that performs
the bulk of data processing in a computer.
CRC – Acronym for Cyclic Redundancy
Check. An error detection code that is
recorded within each sector and is used to see
whether parts of a string of data are missing
or erroneous.
CYLINDER – On a disk drive that has more
than one recording surface and heads that
move to various tracks, the group of all tracks
located at a given head position. The number
of cylinders times the number of heads equals
the number of tracks per drive.
D
DATA SEPARATOR – On a disk drive that
stores data and timing information in an
encoded form, the circuit that extracts the
data from the combined data and clock signal.
DEDICATED SERVO – A surface separate
from the surface used for data that contains
only disk timing and positioning information
and contains no data.
DEFECT MANAGEMENT – A method
that is implemented to ensure long term data
integrity. Defect management eliminates the
need for user defect maps. This is
accomplished by scanning the disk drives at
the factory for defective sectors. Defective
sectors are deallocated prior to shipment. In
addition, during regular use, the drive
continues to scan and compensate for any
new defective sectors on the disk.
DISK – In general, any circular-shaped
data-storage medium that stores data on the
flat surface of the platter. The most common
type of disk is the magnetic disk, which stores
data as magnetic patterns in a metal or
metal-oxide coating. Magnetic disks come in
two forms: floppy and hard. Optical
recording is a newer disk technology that
gives higher capacity storage but at slower
access times.
DISK CONTROLLER – A plug-in board,
or embedded circuitry on the drive, that
passes information to and from the disk. The
Maxtor disk drives all have controllers
embedded on the drive printed-circuit board.
DISKWARE – The program instructions
and data stored on the disk for use by a
processor.
DMA – Acronym for direct memory access.
A process by which data moves directly
between a disk drive (or other device) and
system memory without passing through the
CPU, thus allowing the system to continue
processing other tasks while the new data is
being retrieved.
DRIVE – Short form of disk drive.
DRIVE GEOMETRY – The functional
dimensions of a drive in terms of the number
of heads, cylinders, and sectors per track. See
also logical format.