Dell Latitude C640 User Manual page 167

It is located on a network in a directory and the system administrator has assigned read-only rights to
you.
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.
reserve battery - A battery that keeps your computer clock and certain circuitry working.
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 even after you turn off 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.
S
ScanDisk - A Microsoft utility that checks files, folders, and the hard drive's surface for errors. ScanDisk
often runs after a lockup occurs.
SDRAM - synchronous dynamic random-access memory
A type of DRAM that is synchronized with the optimal clock speed of the microprocessor.
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 or technical support.