Maxtor MaxLine Plus II 250GB AT Product Manual page 71

K
KILOBYTE (K) – A unit of measure
10
consisting of 1,024 (2
L
LANDING ZONE – A position inside the
disk's inner cylinder in a non data area
reserved as a place to rest the heads during the
time that power is off. Using this area
prevents the heads from touching the surface
in data areas upon power down, adding to the
data integrity and reliability of the disk drive.
LATENCY – The period of time during
which the read/write heads are waiting for the
data to rotate into position so that it can be
accessed. Based on a disk rotation speed of
3,662 rpm, the maximum latency time is 16.4
milliseconds, and the average latency time is
8.2 milliseconds.
LOGICAL FORMAT – The logical drive
geometry that appears to an AT system BIOS
as defined by the drive tables and stored in
CMOS. With an installation program like
Disk Manager, the drive can be redefined to
any logical parameters necessary to adapt to
the system drive tables.
LOOK AHEAD – The technique of
buffering data into cache RAM by reading
subsequent blocks in advance to anticipate
the next request for data. The look ahead
technique speeds up disk access of sequential
blocks of data.
LOW-LEVEL FORMATTING –
Formatting that creates the sectors on the
platter surfaces so the operating system can
access the required areas for generating the
file structure. Maxtor drives are shipped with
the low-level formatting already done.
LOW PROFILE – Describes drives built to
the 3 1/2-inch form factor, which are only 1
inch high.
) bytes.
M
MB – See megabyte.
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 1,024 kilobytes, or
1,048,576 bytes except when referring to disk
storage capacity.
1 MB = 1,000,000 bytes when referring to
disk storage capacity.
See also kilobyte.
MEGAHERTZ – A measurement of
frequency in millions of cycles per second.
MHz – See megahertz.
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 functions of the drive and to support
the embedded controller.
MICROSECOND (µs) – One millionth of a
second (.000001 sec.).
MILLISECOND (ms) – One thousandth of
a second (.001 sec.).
MTTF – MTTF is a basic measure of
reliability for non-repairable systems. It is the
mean time expected until the first failure of a
piece of equipment. MTTF is a statistical
value and is meant to be the mean over a long
period of time and large number of units. For
constant failure rate systems, MTTF is the
inverse of the failure rate. If failure rate is in
failures/million hours, MTTF = 1,000,000 /
Failure Rate for components with
exponential distributions.
MaXLine Plus II 250GB AT
Glossary
G-5