Users Guide

148 Glossary
PXE
Abbreviation for Pre-boot eXecution Environment.
QFP
Abbreviation for quad flat pack.
RAC
Acronym for remote access controller.
RAID
Acronym for redundant array of independent drives.
RAM
Acronym for random-access memory. A system's
primary temporary storage area for program
instructions and data. Each location in RAM is
identified by a number called a memory address.
Any information stored in RAM is lost when you turn
off your system.
RAMDAC
Acronym for random-access memory
digital-to-analog converter.
RAW
Unprocessed. The term refers to data that is passed
along to an I/O device without being interpreted. In
contrast, cooked refers to data that is processed before
being passed to the I/O device. It often refers to
uncompressed text that is not stored in any proprietary
format. The term comes from UNIX, which supports
cooked and raw modes for data output to a terminal.
RBAC
Abbreviation for role-based access control.
RDRAM
Acronym for Rambus DRAM. A dynamic RAM chip
technology from Rambus, Inc. Direct RDRAMs are
used in systems. Direct RDRAM chips are housed in
RIMM modules, which are similar to DIMMs but have
different pin settings. The chips can be built with dual
channels, doubling the transfer rate to 3.2 GB/sec.
read-only file
A read-only file is one that you are prohibited from
editing or deleting. A file can have read-only status if:
• Its read-only attribute is enabled.
• It resides on a physically write-protected diskette or
on a diskette in a write-protected drive.
• It is located on a network in a directory to which the
system administrator has assigned read-only rights
to you.
readme file
A text file included with a software package or hardware
product that contains information supplementing or
updating the documentation for the software or
hardware. Typically, readme files provide installation
information, describe new product enhancements or
corrections that have not yet been documented, and
list known problems or other things you need to be
aware of as you use the software or hardware.
real mode
An operating mode supported by 80286 or higher
microprocessors, real mode imitates the architecture of
an 8086 microprocessor.
refresh rate
The rate at which the monitor redraws the video image
on the monitor screen. More precisely, the refresh rate
is the frequency, measured in Hz, at which the 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.
The higher refresh rates are also noninterlaced.
remote management system
A remote management system is any system that
accesses the Server Administrator home page on a
managed system from a remote location using a
supported Web browser. See managed system.
RFI
Abbreviation for radio frequency interference.