EGA's native graphics modes are planar, as opposed to the interleaved CGA and Hercules modes. Video memory is divided into four "planes" (except × 2, which has one plane), one for each component of the RGBI color space. Each pixel is represented by one bit in each plane. If a bit in the red plane is on, but none of the equivalent bits in the other pages are, a red pixel will appear in that location on screen. If all the other bits for that particular pixel were also on, it would become white, and so forth.
EGA's native graphics modes are planar, as opposed to the interleaved CGA and Hercules modes. Video memory is divided into four ",planes" (except × 2 which has one plane), one for each component of the RGBI color space. Each pixel is represented by one bit in each plane. If a bit in the red plane is on but none of the equivalent bits in the other pages are, a red pixel will appear in that location on screen. If all the other bits for that particular pixel were also on, it would beco,me white, and so forth.