Maxtor ATLAS 10K III - Manual (Page 272)

Glossary
G-6 Maxtor Atlas 10K III 18/36/73 GB Ultra160 SCSI
command or a group of linked commands. An
I/O process normally ends with a BUS FREE
phase following a COMMAND COMPLETE
or a RELEASE RECOVERY message.
,
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.
-
KILOBYTE (K) – A unit of measure consisting
of 1,024 (2
10
) bytes.
.
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
initialization .
LOW PROFILE – Describes drives built to the
3 1/2-inch form factor, which are only 1 inch
high. 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 megabyte .
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
kilobyte .)
MEGAHERTZ – A measurement of frequency
in millions of cycles per second.
MHz – See megahertz .