Enhanced Graphics Adapter

An IBM EGA card.

The Enhanced Graphics Adapter (EGA) is a graphics card which gives IBM Personal Computers color graphics capabilities superior to those of the earlier Color Graphics Adapter. It was designed and developed by IBM and first sold in 1984, but competing companies quickly reverse-engineered it and sold clones. The display type was extremely popular for MS-DOS programs through the mid to late 1980s. IBM also sold a more advanced Professional Graphics Controller, but it was out of the price range for home users. The EGA was superseded in 1987 by the Video Graphics Array (VGA) which added superior color graphic capabilities, although software continued to support EGA for years to follow.

Personal

I spent a lot of my childhood acquainted with EGA graphics, not just because a lot of games I played used it, but because it was a very popular QuickBASIC screen (screen 7). Even though I haven't bothered with it in decades, I still have the default EGA color palette memorized.

Technical Specifications

Display Modes

EGA is backward-compatible with CGA and supports its text and graphic modes, but also adds higher resolution modes. When running in CGA modes, it uses the same dimensions and colors. EGA adds two text modes and four new graphics modes.

When running in 640×350 graphic mode, EGA supports 4-bit color (16 distinct colors at once) chosen from a palette of 64 colors. However, in order to maintain backward compatibility, when running in 320×200 graphics mode, the color palette is always fixed to the CGA default, even though the CGA couldn't support 16 colors at 320×200.

Mode	Pixel Resolution	Text Resolution	Colors	Pixel Aspect Ratio	Notes
Text	640 × 350	80 × 25 (8 × 14 pixel font)	16 (from a palette of 64)	1:1.37
Text	640 × 350	80 × 43 (8 × 8 pixel font)	16 (from a palette of 64)	1:1.37
Text	640 × 200	80 × 25 (8 × 8 pixel font)	16	1:2.4	CGA backward compatibility.
Text	320 × 200	40 × 25 (8 × 8 pixel font)	16	1:1.2	CGA backward compatibility.
Graphics	640 × 350		16 (from a palette of 64)	1:1.37
Graphics	640 × 200		16 (from a palette of 64)	1:2.4
Graphics	320 × 200		16	1:1.2
Graphics	640 × 350		2	1:1.37
Graphics	320 × 200		4	1:1.2	CGA backward compatibility.
Graphics	640 × 200		2	1:2.4	CGA backward compatibility.

Examples

Actual data from King's Quest IV
(320x200 resolution, 1:1 pixel ratio)

Simulated monitor (1:1.2 pixel ratio).

Actual data from SimAnt: The Electronic Ant Colony
(640x350 resolution, 1:1 pixel ratio).

Simulated monitor (1:1.37 pixel ratio).

Color Palette

The complete EGA color palette.

All games designed for EGA's high-res modes could technically modify the default palette, though few developers ever took advantage of this feature, excepting Maxis, which is a real shame since the default palette isn't conducive to attractive art. The following software modifies the palette.

In QuickBASIC, screens 0 and 9 support customizing the default 16 colors of the EGA palette with the command PALETTE index, color, where index was one of the 0-15 colors and color was one of the 64 possible colors.

Software

All software that used 4-bit Color

These are programs that I think made good use of EGA graphics:

Commander Keen IV: Secret of the Oracle

Large attractive graphics.
King's Quest IV: The Perils of Rosella

Good use of dithering to simulate additional colors.
Lemmings

Hi-res with a custom palette.
Loom

Great use of dithering to create gradients.
The Secret of Monkey Island

More advanced use of dithering.
SimAnt: The Electronic Ant Colony

Hi-res with a custom palette. Uses red (36), blue (9), and yellow (54).