EGA - standard for monitors and video adapters for IBM PC

Located between CGA and VGA in terms of its characteristics (color and spatial resolution). Released by IBM in 1984 for the new IBM PC AT personal computer. The EGA video adapter allows the use of 16 colors at a resolution of 640×350 pixels. The video adapter is equipped with 16 kB of ROM to expand the BIOS graphics functions.

The EGA adapter with a resolution of 640*350 allows you to simultaneously use 16 colors out of a possible 64 (two bits each for the red, green and blue components). EGA also supports 16-color CGA 640*200 and 320*200 graphics mode options; in this case, you can only use colors from the CGA palette. Native CGA modes are also supported, although EGA is not fully hardware compatible with CGA. EGA can output images to an MDA monitor; this feature is enabled using switches on the board; only 640*350 mode is available. The EGA board connects to the ISA bus, starting with the 8-bit version. The basic version of EGA had 64 KB of video memory, which was enough for high-resolution monochrome graphics and color graphics in 640*200 and 320*200 modes. Over time, most EGA boards began to be produced with 256 KB of video memory. Some third-party EGA clones (notably ATI Technologies and Paradise) support advanced graphics modes (such as 640*400, 640*480, and 720*540), automatic monitor type detection, and sometimes a special interlaced mode for CGA monitors. The EGA standard was replaced by the VGA standard, introduced by IBM in April 1987 with the PS/2 computer model.

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