Video Monitor/Display Types
Our computer's monintors use a a video display standard
to present information to the screen. When you purchase
a computer it will have a component in it refered to as
the display or video/graphics display card. This is the
hardware that implements the video display standards.
Below is a list of some of the standards commonly supported.
Below is a table representing some of the video display
standards. Note that some of the numbers are only
minimums.
| Video Standard | Resolution | Simultaneous Colors |
| VGA (Video Graphics Array) | 640 by 480 | 16 |
| 320 by 200 | 256 |
| | |
| SVGA | 800 by 600 | 16 |
| 1,024 by 768 | 256 |
| 1,280 by 1,024 | 256 |
| 1,600 by 1,200 | 256 |
| | |
| 8514/A | 1,024 by 768 | 256 |
| | |
| XGA (Extended Graphics Array) | 640 by 480 | 65,536 |
| 1,024 by 768 | 256 |
| | |
| TI 34010 | 1,024 by 768 | 256 |
VGA
VGA stands for video graphics array, a graphics display system for PCs
developed by IBM. VGA has become one of the de facto standards for PCs.
In text mode, VGA systems provide a resolution of 720 by 400 pixels. In
graphics mode, the resolution is either 640 by 480 (with 16 colors) or 320 by
200 (with 256 colors). The total palette of colors is 262,144.
Unlike earlier graphics standards for PCs --MDA, CGA, and EGA --VGA
uses analog signals rather than digital signals. Consequently, a monitor
designed for one of the older standards will not be able to use VGA.
Since its introduction in 1987, several other standards have been
developed that offer greater resolution and more colors (see SVGA ,
8514/A graphics standard , and XGA), but VGA remains the lowest
common denominator. All PCs made today support VGA, and
possibly some other more advanced standard.
SVGA
Short for Super VGA, a set of graphics standards designed to offer greater
resolution than VGA. There are several varieties of SVGA, each providing a
different resolution:
- 800 by 600 pixels
- 1024 by 768 pixels
- 1280 by 1024 pixels
- 1600 by 1200 pixels
All SVGA standards support 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 16
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 (Video Electronics Standards
Association).
8514/A
A high-resolution video standard for PCs developed by IBM in 1987. It is
designed to extend the capabilities of VGA. The 8514/A standard provides a
resolution of 1,024 by 768 pixels, which gives it about 2.5 times the pixels of
VGA (640 by 480). Like VGA, 8514/A provides a palette of 262,000
colors, of which 256 can be displayed at one time. On monochrome displays,
8514/A provides 64 shades of gray.
In its original version, 8514/A relies on interlacing, a technique that makes it
possible to provide resolution at low cost. Interlacing, however, carries a
performance penalty, so many manufacturers produce noninterlaced 8514/A
clones.
TI 34010
A video standard from Texas Instruments that supports a resolution of 1,024
by 768. TI 34010 conforms to TI's Graphics Architecture (TIGA). Unlike
IBM's 8514/A, which supports the same resolution, TI 34010 is
noninterlaced.
XVGA
Short for extended graphics array, a high-resolution graphics standard
introduced by IBM in 1990. XGA was designed to replace the older 8514/A
video standard. It provides the same resolutions (640 by 480 or 1024 by 768
pixels), but supports more simultaneous colors (65 thousand compared to
8514/A's 256 colors). In addition, XGA allows monitors to be
non-interlaced.
Some of the information above was taken from PC WEBOPEDIA