renejr902 wrote on 2025-10-13, 10:28:

something cool

Super offroad have a choice of ega 64 colors and it works great when i switch to 64 colors on the monitor in manual mode. the automatic mode didn't detect the 64 colors mode

Hi! Thanks for the pictures! 🙂👍
The 64 color mode was known to be troublesome, I think.
It basically has to do with it being linked to the IBM 5154 "hi-res" monitor.
You know, the real EGA monitor that can do EGA's native 640x350 pixel resolution.
Unfortunatwlly, many home users have/had an ordinary CGA monitor or RGB TV set connected to EGA card however.
Which are assumed to not have RrGgBb capabilities like a real EGA monitor, but ordinary RGBI (like CGA uses it).
So both the EGA card and the EGA monitor must support/use 64c mode.
Interestingly, the EGA monitor can display 64c at once but the EGA card has to switch between four 16c palettes to display them all.
That's the short story, in a nutshell, basically. I'm just a layman here.

Here are some interesting videos on YouTube, they also cover Super Off Road game.

This monitor is the same as the IBM 5154 EGA monitor! (Samsung CD-1452M)
https://www.youtube.com/watch?v=7EezG5OzSQo

Ivan "Ironman" Stewart's Super Off Road - Compare IBM PC DOS version - CGA, EGA, EGA 64 & VGA
https://www.youtube.com/watch?v=JDnuzJ2_7SA

EGA 64 color palette in Ironman Super Off Road (with PVM)
https://www.youtube.com/watch?v=Lp_WmdciZ3Y

PS: That Snoopy game of '89 has 64c mode, too. :)
https://www.mobygames.com/game/11595/snoopy-t … -computer-game/

Jo22 wrote on 2025-10-13, 12:11:

The 64 color mode was known to be troublesome, I think. It basically has to do with it being linked to the IBM 5154 "hi-res" mon […]
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The 64 color mode was known to be troublesome, I think.
It basically has to do with it being linked to the IBM 5154 "hi-res" monitor.
You know, the real EGA monitor that can do EGA's native 640x350 pixel resolution.
Unfortunatwlly, many home users have/had an ordinary CGA monitor or RGB TV set connected to EGA card however.
Which are assumed to not have RrGgBb capabilities like a real EGA monitor, but ordinary RGBI (like CGA uses it).
So both the EGA card and the EGA monitor must support/use 64c mode.
Interestingly, the EGA monitor can display 64c at once but the EGA card has to switch between four 16c palettes to display them all.
That's the short story, in a nutshell, basically. I'm just a layman here.

The 16/64 color issue is not primarily about people connecting a CGA monitor (or TV with RGB input to an EGA card), but IBMs idea that the EGA monitor should work out-of-the-box with CGA cards. You are supposed to use a different DIP switch settings on the EGA card if you connect a CGA monitor than if you connect an EGA monitor, so the EGA BIOS would be able to react to different monitor types. The IBM 5154 connected to a CGA card is supposed to work "just like the 5153". This monitor is meant as an extended 5153. As the 5153 only supports 16 colors, the 5154 in "CGA mode" only supports 16 colors. Only if the 5154 operates in "EGA mode", it supports 64 colors. At the same time, "CGA mode" is associated with a horizontal frequency of 15.6kHz and 200 active scanlines, while "EGA mode" is associated with a horizontal frequency of 21.8kHz and 350 scanlines. For that reason, all 200-line modes, even the 16-color EGA graphics modes, operate the 5154 monitor in "CGA mode", in which only the classic 16 CGA colors are supported.

There are no four 16c palettes on the EGA card, though. While the EGA video generation logic always generates a image consisting of 16 colors (numbered 0..15), any arbitrary assignment of EGA colors to these 16 color numbers is possible. This is different to the CGA card that had multiple fixed sets of colors that could be applied to map the color number 1..3 in graphics mode to CGA color numbers.

very interesting info, thanks guys