Super Video Graphics Array
From Wikipedia, the free encyclopedia
Super Video Graphics Array, almost always abbreviated to Super VGA or just SVGA is a broad term that covers a wide range of computer display standards.[1]
Originally, it was an extension to the VGA standard first released by IBM in 1987. Unlike VGA—a purely IBM-defined standard—Super VGA was defined by the Video Electronics Standards Association (VESA), an open consortium set up to promote interoperability and define standards. When used as a resolution specification, in contrast to VGA or XGA for example, the term SVGA normally refers to a resolution of 800 × 600 pixels.
Super VGA was first defined in 1989. In that first version, it called for a resolution of 800 × 600 4-bit pixels. Each pixel could therefore be any of 16 different colours. It was quickly extended to 1024 × 768 8-bit pixels, and well beyond that in the following years.
Although the number of colours was defined in the original specification, this soon became irrelevant as (in contrast to the old CGA and EGA standards) the interface between the video card and the VGA or Super VGA monitor uses simple analog voltages to indicate the desired colour depth. In consequence, so far as the monitor is concerned, there is no theoretical limit to the number of different colours that can be displayed. Note that this applies to any VGA or Super VGA monitor.
While the output of a VGA or Super VGA video card is analog, the internal calculations the card performs in order to arrive at these output voltages are entirely digital. To increase the number of colours a Super VGA display system can reproduce, no change at all is needed for the monitor, but the video card needs to handle much larger numbers and may well need to be redesigned from scratch. Even so, the leading graphics chip vendors were producing parts for high-colour video cards within just a few months of Super VGA's introduction.
On paper, the original Super VGA was to be succeeded by Super XGA, but in practice the industry soon abandoned the attempt to provide a unique name for each higher display standard, and almost all display systems made between the late 1990s and the early 2000s are classed as Super VGA.
Monitor manufacturers sometimes advertise their products as XGA or Super XGA. In practice this means little, since all Super VGA monitors manufactured since the later 1990s have been capable of at least XGA and usually considerably higher performance.
SVGA uses a VGA connector, the same DE-15 (a.k.a. HD-15) as the original standard.
See also Digital Visual Interface which is a common non-analog cable for SVGA and other resolutions.
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[edit] First manufacturers
Some of the early SuperVGA manufacturers (in parenthesis, some of their models, where available) were:
- Ahead Technologies Not related with Ahead Software AG.
- Amdek (VGA ADAPTER/132)
- AST Research, Inc. (VGA Plus)
- ATI Technologies (VIP, VGA Wonder)
- Chips and Technologies
- Compaq (VGC Board)
- Everex
- Genoa Inc. (Genoa VGA)
- Orchid Technology (Designer VGA, Pro Designer Plus)
- Paradise Inc. (VGA Plus, VGA Plus 16, VGA Pro)
- Sigma Designs (SigmaVGA)
- STB Technologies (VGA Extra EM)
- Tecmar (Tecmar VGA, VGA AD)
- Trident Microsystems (8800, 8900)
- Tseng Labs (ET3000, ET4000)
- Video 7 (FastWrite, V-RAM VGA)
- Willow (VGA-TV/Publisher's, VGA-TV + Genlock)
[edit] WSVGA
The Wide version of SVGA is known as WSVGA, featured on devices such as the Samsung Q1U.
[edit] Comparison chart
| Name | x (width) |
y (height) |
Pixels (x1 Million) |
Aspect Ratio |
Percentage of difference in pixels | Widescreen Version |
Typical screen sizes |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| VGA | SVGA | XGA | XGA+ | SXGA | SXGA+ | UXGA | QXGA | |||||||
| VGA | 640 | 480 | 0.31 | 1.33 | 0% | -36% | -61% | -69% | -77% | -79% | -84% | -90% | WVGA | |
| SVGA | 800 | 600 | 0.48 | 1.33 | 56% | 0% | -39% | -52% | -63% | -67% | -75% | -85% | ||
| XGA | 1024 | 768 | 0.79 | 1.33 | 156% | 64% | 0% | -21% | -40% | -47% | -59% | -75% | WXGA | 15"/ 38cm |
| XGA+ | 1152 | 864 | 1.00 | 1.33 | 224% | 107% | 27% | 0% | -24% | -32% | -48% | -68% | WXGA+ | 17"/ 43cm |
| SXGA | 1280 | 1024 | 1.31 | 1.25 | 327% | 173% | 67% | 32% | 0% | -11% | -32% | -58% | WSXGA | 17-19"/ 43-48cm |
| SXGA+ | 1400 | 1050 | 1.47 | 1.33 | 379% | 206% | 87% | 48% | 12% | 0% | -23% | -53% | WSXGA+ | |
| UXGA | 1600 | 1200 | 1.92 | 1.33 | 525% | 300% | 144% | 93% | 46% | 31% | 0% | -39% | WUXGA | 20"/ 51cm |
| QXGA | 2048 | 1536 | 3.15 | 1.33 | 924% | 555% | 300% | 216% | 140% | 114% | 64% | 0% | WQXGA | 30"/ 76cm |
[edit] References
- ^ Vipul Verma. Same monitor yet better viewing. www.tribuneindia.com. Retrieved on 2008-03-26.
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