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Dell Latitude D430 (Mid 2007) User Manual

Page 145

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Glossary

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the devices attached to it. PCI Express can transfer data at

speeds from 250 MB/sec to 4 GB/sec. If the PCI Express

chip set and the device are capable of different speeds,

they will operate at the slower speed.
PCMCIA — Personal Computer Memory Card

International Association — The organization that

establishes standards for PC Cards.
PIO — programmed input/output — A method of

transferring data between two devices through the

processor as part of the data path.
pixel — A single point on a display screen. Pixels are

arranged in rows and columns to create an image. A video

resolution, such as 800 x 600, is expressed as the number

of pixels across by the number of pixels up and down.
Plug-and-Play — The ability of the computer to

automatically configure devices. Plug and Play provides

automatic installation, configuration, and compatibility

with existing hardware if the BIOS, operating system, and

all devices are Plug and Play compliant.
POST — power-on self-test — Diagnostics programs,

loaded automatically by the BIOS, that perform basic

tests on the major computer components, such as

memory, hard drives, and video. If no problems are

detected during POST, the computer continues the start-

up.
processor — A computer chip that interprets and executes

program instructions. Sometimes the processor is referred

to as the CPU (central processing unit).
PS/2 — personal system/2 — A type of connector for

attaching a PS/2-compatible keyboard, mouse, or keypad.
PXE — pre-boot execution environment — A WfM

(Wired for Management) standard that allows networked

computers that do not have an operating system to be

configured and started remotely.

R

RAID — redundant array of independent disks — A

method of providing data redundancy. Some common

implementations of RAID include RAID 0, RAID 1,

RAID 5, RAID 10, and RAID 50.
RAM — random-access memory — The primary

temporary storage area for program instructions and data.

Any information stored in RAM is lost when you shut

down your computer.
readme file — A text file included with a software package

or hardware product. Typically, readme files provide

installation information and describe new product

enhancements or corrections that have not yet been

documented.
read-only — Data and/or files you can view but cannot

edit or delete. A file can have read-only status if:

• It resides on a physically write-protected floppy disk,

CD, or DVD.

• It is located on a network in a directory and the

system administrator has assigned rights only to

specific individuals.

refresh rate — The frequency, measured in Hz, at which

your screen's horizontal lines are recharged (sometimes

also referred to as its vertical frequency). The higher the

refresh rate, the less video flicker can be seen by the

human eye.
resolution — The sharpness and clarity of an image

produced by a printer or displayed on a monitor. The

higher the resolution, the sharper the image.
RFI — radio frequency interference — Interference that

is generated at typical radio frequencies, in the range of 10

kHz to 100,000 MHz. Radio frequencies are at the lower

end of the electromagnetic frequency spectrum and are

more likely to have interference than the higher frequency

radiations, such as infrared and light.
ROM — read-only memory — Memory that stores data

and programs that cannot be deleted or written to by the

computer. ROM, unlike RAM, retains its contents after

you shut down your computer. Some programs essential to

the operation of your computer reside in ROM.
RPM — revolutions per minute — The number of

rotations that occur per minute. Hard drive speed is often

measured in rpm.
RTC — real time clock — Battery-powered clock on the

system board that keeps the date and time after you shut

down the computer.
RTCRST — real-time clock reset — A jumper on the

system board of some computers that can often be used