EGA Aesthetics @ega-aesthetics - Tumblr Blog

— HEROES OF MIGHT AND MAGIC III | February 28, 1999

EGA 64-color 320x200 mode on switchable monitors

Standard EGA cards can display up to 16 different colors on screen at the same time. Although not many games and programs took advantage of it, EGA is not limited to the 16-color palette used with CGA. The improved digital output has two TTL pins for each of three color components (rgbRGB). That gives you 64 colors in total (four shades for each component). However, IBM wanted to allow users to use old CGA monitors with EGA cards and decided to officially support only the 16-color CGA palette in all 200-line modes. Only the hi-res 640x350 was officially allowed to work with 16 colors out of the extended 64-color palette.

This limitation is, however, in standard EGA monitors, not the EGA card itself. Therefore you can easily switch even the original IBM EGA to produce rgbRGB in 320x200. The monitor side can be solved using a “switchable” monitor. Such monitor usually has a mechanical switch which forces it to accept the rgbRGB 64-color signal in any resolution. These universal monitors were designed to support multiple computer platforms (including those with analog output) so they allowed to bypass the IBM’s restrictions.

Not many games were produced with support for this unofficial mode. I know only about Ironman Super Off Road. By using this mode, you get almost the same quality as with the VGA version of the game. It looks much better than the standard EGA. Some monitors replaces dark shades of yellow with shades of brown even in the rgbRGB mode (visible on the photos of the CRT above) but the result still looks good.

It’s sad that IBM didn’t care and didn’t find a better way to allow game developers to use the full potential of EGA.