Dell PowerEdge 2300 User Manual page 161

Graphics-mode application programs and
operating environments, such as Win-
dows, often require video drivers in order
to display at a chosen resolution with the
desired number of colors. A program may
include some "generic" video drivers.
Any additional video drivers may need to
match the video adapter; you can find
these drivers on a separate diskette with
your computer or video adapter.
Most VGA and SVGA video adapters in-
clude VRAM or DRAM memory chips in
addition to your computer's RAM. The
amount of video memory installed prima-
rily influences the number of colors that a
program can display (with the appropriate
video drivers and monitor capability).
Video adapters normally support multiple
text and graphics display modes. Charac-
ter-based software (such as MS-DOS)
displays in text modes that can be defined
as x columns by y rows of characters. Graph-
ics-based software (such as Windows)
displays in graphics modes that can be de-
fined as x horizontal by y vertical pixels by z
colors.
Video resolution—640 x 480, for exam-
ple—is expressed as the number of pixels
across by the number of pixels up and
down. To display a program at a specific
graphics resolution, you must install the
appropriate video drivers and your moni-
tor must support the resolution.
An operating mode supported by Intel386
or higher microprocessors, virtual 8086
mode allows operating environments—
such as Windows—to run multiple pro-
grams in separate 1-MB sections of
memory. Each 1-MB section is called a
virtual machine .
A method for increasing addressable
RAM by using the hard-disk drive.
(MS-DOS does not support true virtual
memory, which must be implemented at
the operating system level.) For example,
in a computer with 8 MB of RAM and
16 MB of virtual memory set up on the
hard-disk drive, the operating system
would manage the system as though it
had 24 MB of physical RAM.
A self-starting program designed to incon-
venience you. Virus programs have been
known to corrupt the files stored on a
hard-disk drive or to replicate themselves
until a system or network runs out of
memory.
The most common way that virus pro-
grams move from one system to another
is via "infected" diskettes, from which
they copy themselves to the hard-disk
drive. To guard against virus programs,
you should do the following:
Periodically run a virus-checking util-
ity on your computer's hard-disk
drive
Always run a virus-checking utility on
any diskettes (including commer-
cially sold software) before using
them
An abbreviation for VESA local bus. A
standard for local bus implementation de-
veloped by the Video Electronics
Standards Association.
Abbreviation for very-large-scale
integration.
Abbreviation for peak-point voltage.
Abbreviation for video random-access
memory. Some video adapters use VRAM
chips (or a combination of VRAM and
DRAM) to improve video performance.
VRAM is dual-ported, allowing the video
adapter to update the screen and receive
new image data at the same time.
Abbreviation for watt(s).
Glossary 15