Filter
Top Products
Glossary 13
It resides on a physically write-
protected diskette.
It is located on a network in a
directory to which the system
administrator has assigned read-
only rights to you.
UHDOPRGH
An operating mode supported by 80286
or higher microprocessors, real mode
imitates the architecture of an 8086
microprocessor. Designed to run in real
mode, MS-DOS (unassisted by additional
software techniques) can address only
640 KB of conventional memory.
UHIUHVKUDWH
The frequency, measured in Hz, at which
the screen’s horizontal lines are re-
charged. A monitor’s refresh rate is also
referred to as its
vertical frequency
.
5(1
Abbreviation for ringer equivalence
number.
5),
Abbreviation for radio frequency
interference.
5*%
Abbreviation for red/green/blue.
520
Acronym for read-only memory. Your
computer contains some programs es-
sential to its operation in ROM code.
Unlike RAM, a ROM chip retains its
contents even after you turn off your com-
puter. Examples of code in ROM include
the program that initiates your computer’s
boot routine and the POST.
USP
Abbreviation for revolutions per minute.
57&
Abbreviation for real-time clock. Battery-
powered clock circuitry inside the com-
puter that keeps the date and time after
you turn off the computer.
6&6,
Acronym for small computer system in-
terface. An I/O bus interface with faster
data transmission rates than standard
ports. You can connect up to seven devic-
es to one SCSI interface.
6'06
Abbreviation for SCSI device management
system.
6'5$0
Abbreviation for synchronous dynamic
random-access memory.
6(&
Abbreviation for single-edge connector
cartridge.
VHF
Abbreviation for second(s).
VHULDOSRUW
An I/O port used most often to connect a
modem or a mouse to your computer. You
can usually identify a serial port on your
computer by its 9-pin connector.
VKDGRZLQJ
A computer’s system and video BIOS
code is usually stored on ROM chips.
Shadowing refers to the performance-
enhancement technique that copies BIOS
code to faster RAM chips in the upper
memory area (above 640 KB) during the
boot routine.
65$0
Abbreviation for static random-access
memory. Because SRAM chips do not
require continual refreshing, they are sub-
stantially faster than DRAM chips. SRAM
is used mostly for external cache
memory.
VWULSLQJ
In composite drivers with two or more
physical drives, the drive array sub-
system uses a method of data storage
called
striping
. With this method, data is
divided into a series of pieces called
blocks
and each data block is stored on a
different physical drive. When each drive
contains a block of data, the process