Maxtor ATLAS 10K IV User Manual page 244

Glossary
J
JUMPER – A tiny box that slips over two pins on
a circuit board, connecting the pins electrically.
Some board manufacturers use Dual In-Line
Package (DIP) switches instead of jumpers.
K
KILOBYTE (K) – A unit of measure consisting
10
of 1,024 (2 ) bytes.
L
LANDING ZONE – A non-data area on the
disk's inner cylinder where the heads can rest
when the power is off.
LATENCY – The time during which the read/
write heads wait for the data to rotate into
position after the controller starts looking for a
particular data track. If a disk rotates at 3,600
rpm, the maximum latency time is 16.4
milliseconds, and the average latency time is 8.2
milliseconds.
LBA – Abbreviation for Logical Block Address.
A sequentially-numbered identity of a multi-byte
block of user data. It does not refer directly to the
physical location of the data in a disk drive.
LOGICAL FORMAT – The logical drive
geometry that appears to the computer system
BIOS as defined by the drive tables and stored in
CMOS.
LOGICAL UNIT – A physical or virtual
peripheral device addressable through a target.
LOOK AHEAD – The process of anticipating
events in order to speed up computer operations.
For example, the system can buffer data into
cache RAM by reading blocks in advance,
preparing the system for the next data request.
LOW-LEVEL FORMATTING – The process of
creating sectors on the disk surface so that the
operating system can access the required areas
for generating the file structure. Maxtor drives
are shipped with the low-level formatting
already completed. Also known as
LOW PROFILE – Describes drives built to the 3
1/2-inch form factor, which are only 1 inch high.
G-6 Maxtor Atlas 10K IV
The standard form factor drives are 1.625 inches
high.
LPS – Low Profile Series.
LOW-VOLTAGE DIFFERENTIAL (LVD) —
Is a differential bus technology that combines
much of the bus length, noise, immunity, and
performance benefits to conventional
differential SCSI with the power consumption
and cost of single-ended SCSI Interfaces. Ultra2
SCSI (LVD) increase bus data rates to 80
Mbytes/sec, provides differential data integrity,
extends the SCSI bus cable length to 12 meters,
and provides easy system configuration for up to
15 peripherals.
MB – See
MAGNETO-RESISTIVE – A unique
characteristic of some metals, which, when
combined, yields a variable electrical resistance
to varying magnetic fluxes. The resistance varies
directly with the strength of the flux, field, not
simply to a change in flux as with magneto-
inductance.
MEDIA – The magnetic film that is deposited or
coated on an aluminum substrate which is very
flat and in the shape of a disk. The media is
overcoated with a lubricant to prevent damage to
the heads or media during head take off and
landing. The media is where the data is stored
inside the disk in the form of magnetic flux or
polarity changes.
MEGABYTE (MB) – A unit of measurement
equal to 1,000 kilobytes, or 1,024,000 bytes.
(See also
MEGAHERTZ – A measurement of frequency
in millions of cycles per second.
MHz – See
MICROPROCESSOR – The integrated circuit
chip that performs the bulk of data processing
and controls the operation of all of the parts of
the system. A disk drive also contains a
microprocessor to handle all of the internal
initialization.
functions of the drive and to support the
embedded controller.
M
.
megabyte
.)
kilobyte
.
megahertz