164 Glossary
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
for troubleshooting problems.
S
SAS — serial attached SCSI — A faster, serial version of
the SCSI interface (as opposed to the original SCSI
parallel architecture).
SATA — serial ATA — A faster, serial version of the ATA
(IDE) interface.
ScanDisk — A Microsoft utility that checks files, folders,
and the hard disk’s surface for errors. ScanDisk often runs
when you restart the computer after it has stopped
responding.
SCSI — small computer system interface — A high-speed
interface used to connect devices to a computer, such as
hard drives, CD drives, printers, and scanners. The SCSI
can connect many devices using a single controller. Each
device is accessed by an individual identification number
on the SCSI controller bus.
SDRAM — synchronous dynamic random-access memory
— A type of DRAM that is synchronized with the optimal
clock speed of the processor.
serial connector — An I/O port often used to connect
devices such as a handheld digital device or digital camera
to your computer.
Service Tag — A bar code label on your computer that
identifies your computer when you access Dell Support at
support.dell.com or when you call Dell for customer
service or technical support.
setup program — A program that is used to install and
configure hardware and software. The setup.exe or
install.exe program comes with most Windows software
packages. Setup program differs from system setup.
shortcut — An icon that provides quick access to
frequently used programs, files, folders, and drives. When
you place a shortcut on your Windows desktop and
double-click the icon, you can open its corresponding
folder or file without having to find it first. Shortcut icons
do not change the location of files. If you delete a
shortcut, the original file is not affected. Also, you can
rename a shortcut icon.
SIM — Subscriber Identity Module — A SIM card
contains a microchip that encrypts voice and data
transmissions. SIM cards can be used in phones or
portable computers.
smart card — A card that is embedded with a processor
and a memory chip. Smart cards can be used to
authenticate a user on computers equipped for smart
cards.
S/PDIF — Sony/Philips Digital Interface — An audio
transfer file format that allows the transfer of audio from
one file to another without converting it to and from an
analog format, which could degrade the quality of the file.
standby mode — A power management mode that shuts
down all unnecessary computer operations to save energy.
Strike Zone™ — Reinforced area of the platform base
that protects the hard drive by acting as a dampening
device when a computer experiences resonating shock or
is dropped (whether the computer is on or off).
surge protectors — Prevent voltage spikes, such as those
that may occur during an electrical storm, from entering
the computer through the electrical outlet. Surge
protectors do not protect against lightning strikes or
against brownouts, which occur when the voltage drops