A Brief History
The earliest displays for personal computers were monochrome monitors that were used in text-based computer systems in the 1970s. In 1981, IBM introduced the Color Graphics Adapter (CGA). This display system was capable of rendering four colors, and had a maximum resolution of 320 pixels horizontally by 200 pixels vertically. While CGA was ok for simple tasks it certainly could not display adequate graphics.
In 1984, IBM introduced the Enhanced Graphics Adapter (EGA).
It allowed up to 16 different colors and offered resolution of up to 640 x 350. This improved the appearance over earlier displays, and made it possible to read text easily. Nevertheless, EGA did not offer sufficient image resolution for use in graphic design either.
In 1987, IBM introduced the Video Graphics Array (VGA) display system. This has become the accepted minimum standard for PCs. The VGA standard is still used today in some applications.
In 1990, IBM introduced the Extended Graphics Array (XGA) display as a successor to its 8514/A display. A later version, XGA-2 offered 800 x 600 pixel resolution in true color (16 million colors) and 1024 x 768 resolution in 65,536 colors. These two image resolution levels are perhaps the most popular in use even today. Recently, new display technology has given the ability to display vast amounts of pixels into a given area. The table shows display modes and the resolution levels (in pixels horizontally by pixels vertically) that are commonly found today.
The 4 x 3 settings are most common with standard PC type monitors whether they are LCD or CRT’s. In recent times larger displays have become available in the letterbox or landscape style. These are typically used for multimedia and home theatre applications. The letterbox style displays usually operate efficiently at a 16:9 aspect ratio. This therefore changes the overall resolution of the display as noted in the table.
