160 Dell PowerEdge 2100/180 and 2100/200 Systems User’s Guide
pixel
Arranged in rows and columns, a pixel is a single point on
a video display. Video resolution—640 x 480, for exam-
ple—is expressed as the number of pixels across by the
number of pixels up and down.
POST
Acronym for power-on self-test. Before the operating sys-
tem loads when you turn on your computer, the POST tests
various system components such as RAM, the disk drives,
and the keyboard.
ppm
Abbreviation for pages per minute.
PQFP
Abbreviation for plastic quad flat pack, a type of micro-
processor socket in which the microprocessor chip is
permanently mounted.
PRN
A synonym for the MS-DOS device name LPT1.
program diskette set
The set of diskettes from which you can perform a com-
plete installation of an application program. When you
reconfigure a program, you often need its program diskette
set.
protected mode
An operating mode supported by 80286 or higher micro-
processors, protected mode allows operating systems to
implement:
•A memory address space of 16 MB (80286 micro-
processor) to 4 GB (Intel386 or higher
microprocessor)
•Multitasking
•Virtual memory, a method for increasing addressable
memory by using the hard-disk drive
The Windows NT, OS/2, and UNIX® 32-bit operating sys-
tems run in protected mode. MS-DOS cannot run in protected
mode; however, some programs that you can start from
MS-DOS—such as Windows—are able to put the computer
into protected mode.
PS/2
Abbreviation for Personal System/2.
PVC
Abbreviation for polyvinyl chloride.
QIC
Abbreviation for quarter-inch cartridge.
RAM
Acronym for random-access memory. The computer’s pri-
mary 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 computer.
RAMDAC
Acronym for random-access memory digital-to-analog
converter.
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.
•It is located on a network in a directory to which the
system administrator has assigned read-only rights to
you.
real mode
An operating mode supported by 80286 or higher micro-
processors, 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.
refresh rate
The frequency, measured in Hz, at which the screen’s hor-
izontal lines are recharged. A monitor’s refresh rate is also
referred to as its vertical frequency.
REN
Abbreviation for ringer equivalence number.
RFI
Abbreviation for radio frequency interference.
RGB
Abbreviation for red/green/blue.