The EGA could be installed in previously released IBM PCs, but required a ROM upgrade on the mainboard.

By that November's COMDEX, more than a half dozen companies had announced EGA-compatible boards based on C&T's chipset.

[10] By 1985 InfoWorld described EGA as the "next graphics standard", but with "sluggish sales" because of high cost and lack of software support.

The magazine said that "market reaction ... although positive, has not been overwhelming, in part because the EGA's complexity has slowed software vendors' efforts to support it".

[11] Commercial software began supporting EGA soon after its introduction, with The Ancient Art of War, released in 1984.

[12] Microsoft Flight Simulator v2.12,[13][14] Jet,[15] Silent Service,[16] and Cyrus,[17] all released in 1985, offered EGA support, along with Windows 1.0.

Some third-party cards using the EGA specification were sold with the full 128 KB of RAM from the factory, while others included as much as 256 KB to enable multiple graphics pages, multiple text-mode character sets, and large scrolling displays.

EGA cards include a ROM to extend the system BIOS for additional graphics functions, and a custom CRT controller (CRTC).

[26] In the 640 × 350 high-resolution mode, which requires an enhanced EGA monitor, 16 colors can be selected from a palette comprising all combinations of two bits per pixel for red, green and blue.

EGA supports: Text modes: Extended graphics modes of third-party boards:[citation needed] With the EGA, all 16 CGA colors can be used simultaneously, and each can be mapped in from a larger palette of 64 colors (two bits each for red, green and blue).

The CGA's alternate brown color is included in the larger palette, so it can be used without any additional display hardware.

[citation needed] Some EGA monitors are switchable, meaning that they can be set up to use the full palette even in 200-line modes, often through a mechanical switch.

Only a few commercial games were released with support for the extended color palette in 320 × 200 or 640 × 200 (including the DOS version of Super Off Road).

[33][34] When selecting a color from the EGA palette, two bits are used for the red, green and blue channels to signal values of 0, 1, 2 or 3.

[citation needed] Conversely, an EGA monitor should work with a CGA adapter, but if it is not set to CGA mode, the secondary red signal will be grounded (always zero), and the secondary blue will be floating (unconnected), causing all high-intensity colors except brown to display incorrectly, and all colors to potentially have a variable blue tint due to the indeterminate state of the unconnected secondary blue.

[37] For color text and CGA graphics modes, video memory is mapped to 16 KB of addresses beginning at address B8000h, and in monochrome (MDA-compatible) text mode, video memory occupies 16 KB beginning at B0000h.