Enhanced Graphics Adapter

EGA Paradise Card.

Arachne in mode 640×350. The screenshot contains 14 colors.

EGA is an acronym for Enhanced Graphics Adapter, the IBM PC standard specification for graphics display, lying between CGA and VGA in terms of graphics performance (ie i.e., color width and resolution). Introduced in 1984 by IBM for its new IBM Personal Computer/AT, EGA had a color depth of 16 colors and a resolution of up to 640×350 pixels. The EGA card had 16 kilobytes of ROM to extend the BIOS with additional features and included the Motorola 6845 video address generator.

Each of the 16 colors could be assigned an RGB color from a palette in high-resolution 640×350 mode; EGA allowed to choose the colors from a palette of 64 different ones (two bits per pixel for red, green and blue). EGA also included CGA's full 16-color feature in 640x200 and 320x200 graphics modes; only 16 CGA/RGBI colors were available in this mode. The original CGA modes were present, but EGA was not 100% CGA compatible. EGA could also control an MDA monitor by setting jumpers on the board; only at 640×350.

The basic IBM EGA card included 64 KiB of video memory, enough to drive a high-resolution monochrome monitor (and allowing all colors at 640×200 and 320×200), although most EGA cards and his clones included 256 KiB of memory. Some third-party EGA clones (mainly cards from ATI Technologies and Paradise) included an extended graphics range (for example, 640x400, 640x480, and 720x540), as well as automatic monitor detection, and some a special 400 line mode for use with CGA monitors.

The EGA standard became obsolete with the introduction of VGA by IBM in April 1987 with the IBM Personal System/2.