VGA (Video Graphics Array) is a basic standard for color resolution in computer monitors that, today, represents the lowest common denominator for compatibility. For example, when a computer boots into the Microsoft™ Windows™ operating system, the opening splash screen or Windows logo is presented in VGA mode using a palette of 32 colors and a resolution of 640 x 480. Once the system is fully loaded, the video card’s device driver takes over at a higher resolution.
In the early days of computers, monitors were originally monochrome or two-color. This was followed by IBM’s Color Graphics Adapter (CGA) in 1981 that boasted a 4-bit palette of 8 colors and a maximum resolution of 640 x 280. The adapter was standard in the new IBM personal computer line, known as the IBM PC.
In 1984 IBM introduced an upgraded video card. The Enhanced Graphics Adapter (EGA) built on the previous standard by doubling the color palette to 16 colors at a resolution of 640 x 350. This video card coincided with the new IBM PC Advanced Technology line, better known as the IBM PC-AT, or simply, “an AT.” The AT had specific motherboard technology and configuration parameters that became an ad-hoc standard for clones, whose motherboard footprints and cases were deemed “ATs” because they conformed to the IBM standard.
In 1987 IMB introduced VGA, which manufacturers adopted en masse. This led to the longstanding tradition of VGA being the “base” or “fall back” display standard of video hardware. Every modern graphics adapter or card is capable of displaying the VGA mode, but will only do so if the proper device driver is not present or cannot be located; if it has been purposely disabled; or if the operating system cannot find a better driver. In Windows operating systems, booting into Safe Mode will display VGA, as unnecessary device drivers are not loaded in this case.
IBM did replace VGA in 1990 with XGA (eXtended Graphics Array), but by this time the Video Electronics Standards Association (VESA) had released a similar standard referred to as Super VGA (SVGA). XGA was capable of 65,536 colors at a resolution of 800 x 600, or 256 colors at 1024 x 768, similar to early SVGA standards. Accordingly, Super XGA (SXGA), Ultra XGA (UXGA) and Quad XGA (QXGA) followed, along with many others.
Display standards evolved rapidly from this point forward with many grouped under the general heading of “SVGA.” Widescreen flavors feature a “W” in front of the display acronym, such as “WXGA.” Just as video cards have a maximum resolution, so do computer monitors. When purchasing a card or monitor, be sure the highest standards of each device are compatible.