A video standard that allows for resolutions up to
640x480 with up to 16 colors at a time. It also allows for 320x200 resolution
with 256 colors. Many older computer games were written to take advantage of the
320x200 resolution because of the comparatively high color depth. SVGA and XGA
replaced VGA, but VGA compatibility remains an important part of most graphics
cards. If your video driver is messed up, versions of Windows, starting with 95
and NT, let you go in under VGA mode to fix your graphics driver.
SVGA
Short for Super VGA, a set of graphics standards
designed to offer greater resolution than VGA. SVGA supports 800 x 600
resolution, or 480,000 pixels. The SVGA standard supports a palette of 16
million colors, but the number of colors that can be displayed simultaneously is
limited by the amount of video memory installed in a system. One SVGA system
might display only 256 simultaneous colors while another displays the entire
palette of 16 million colors. The SVGA standards are developed by a consortium
of monitor and graphics manufacturers called VESA.
XGA
(EXtended Graphics Array) A screen resolution of
1,024x768 pixels. The term stems from IBM's XGA display standard introduced in
1990, which extended VGA to 132-column text and interlaced 1,024x768x256
resolution. XGA-2 later added non-interlaced 1,024x768x64K.
LCD
Short for liquid crystal display, a type of display used in digital watches
and many portable computers. LCD displays utilize two sheets of polarizing
material with a liquid crystal solution between them. An electric current passed
through the liquid causes the crystals to align so that light cannot pass
through them. Each crystal, therefore, is like a shutter, either allowing light
to pass through or blocking the light. Monochrome LCD images usually appear as
blue or dark gray images on top of a grayish-white background. Color LCD
displays use two basic techniques for producing color: Passive matrix is the
less expensive of the two technologies. The other technology, called thin film
transistor (TFT) or active-matrix, produces color images that are as sharp as
traditional CRT displays, but the technology is expensive. Recent passive-matrix
displays using new CSTN and DSTN technologies produce sharp colors rivaling
active-matrix displays.
Most LCD screens used in notebook computers are backlit, or transmissive, to
make them easier to read.
PLASMA
Short for Digital Light Processing, a new technology developed by Texas
Instruments used for projecting images from a monitor onto a large screen for
presentations. Prior to the development of DLP, most computer projection systems
were based on LCD technology which tends to produce faded and blurry images. DLP
uses tiny mirrors housed on a special kind of microchip called a Digital
Micromirror Device (DMD). The result is sharp images that can be clearly seen
even in a normally lit room.
HDTV
Short for High-Definition Television, a new type of television that provides
much better resolution than current televisions based on the NTSC standard. HDTV
is a digital TV broadcasting format where the broadcast transmits widescreen
pictures with more detail and quality than found in a standard analog
television, or other digital television formats. HDTV is a type of Digital
Television (DTV) broadcast, and is considered to be the best quality DTV format
available. Types of HDTV displays include direct-view, plasma, rear screen, and
front screen projection. HDTV requires an HDTV tuner to view and the most
detailed HDTV format is 1080i.
* HDTV Minimum Performance Attributes:
Receiver: Receives ATSC terrestrial digital transmissions and decodes all
ATSC Table 3 video formats Display Scanning Format: Has active vertical scanning
lines of 720 progressive (720p), 1080 interlaced (1080i), or higher Aspect
Ratio: Capable of displaying a 16:9 image1 Audio: Receives and reproduces,
and/or outputs Dolby Digital audio.
EDTV
Short for Enhanced Definition Television, EDTV is a common name for a
particular subset of the DTV (Digital Television) standards, but is considered
to be specifically a part of the HDTV format. EDTV offers advancements over SDTV,
but not near the quality and performance of HDTV. On a large display screen,
EDTV only simulates HDTV viewing quality. EDTV operates as 480p (where 480
represents the vertical resolution and p represents progressive scan). To take
advantage of the 480p standard, you must use a video source that outputs that
signal (i.e. a DVD player) and the display must be able to read the 480p input
signal. EDTV also offers the benefits of Dolby digital surround sound.
* EDTV Minimum Performance Attributes:
Receiver: Receives ATSC terrestrial digital transmissions and decodes all
ATSC Table 3 video formats Display Scanning Format: Has active vertical scanning
lines of 480 progressive (480p) or higher Aspect Ratio: None Specified Audio:
Receives and reproduces, and/or outputs Dolby Digital audio.
