VOGONS


First post, by DaveJustDave

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So I seem to remember a few games would display 64 colors on an EGA adapter with a multisync display.

Are there any image viewers that will display a GIF in 64 colors? If so, what resolution would it be? 320x200? 640x200? 640x350?

I have several EGA adapters with 256k memory, on an IBM 5154. So far the major ones - picem and compushow just scale gifs down to 16 colors.

I have no clue what I'm doing! If you want to watch me fumble through all my retro projects, you can watch here: https://www.youtube.com/user/MrDavejustdave

Reply 1 of 8, by Horun

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320x200 mode on a Multi sync monitor that supports 64 colors "might" work. As far as I know most EGA monitors/EGA cards can only show 16 colors at one time from the 64 possible colors.
The IBM 5154 can only show 16 colors AFAIK from it's docs: " The IBM Enhanced Color Display provides 640 x 350 pel definition from a palette of 64 colors, 16 at one time when operating with the IBM Enhanced Graphics Adapter."
But a different EGA card (like WD Paradise EGA) may be able to force the 5154 to show 64 colors.
Here is some talk at VCfed about it: http://www.vcfed.org/forum/showthread.php?661 … -64-colors-mode:
http://www.vcfed.org/forum/showthread.php?661 … -64-colors-mode
Am sure some one else will have better info about this.....

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. https://archive.org/details/@horun

Reply 2 of 8, by Jo22

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I believe there's a Snoopy/Peanuts game on DOS that supports such a colour count in EGA.
I'm not 100% sure, though.
Edit: Here it is: https://www.mobygames.com/game/dos/snoopy-the … l-computer-game

By the way, is it possible to use PWM to get more colours on an RGB/RGBI monitor?
Must require a very high timing to do so, if it's possible.

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Reply 4 of 8, by pan069

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I don't have an awful lot of experience with EGA, but on VGA, you can switch palettes on a scan line by scan line basis, either change the RGB of a color (limited due to IO time it takes to actually change color values) or by switching to a different predefined color map table (faster since you can change a lot colors all at once with few IO operations).

However, changing palettes on VGA using a technique like this requires that you continuously monitor the scanline position (count the scan lines) and wait for a Horizontal Blank to to occur. I imagine that a similar technique could be used on EGA. That way, each scanline in an image could be mapped to be best matching 16 color palette out of the 64. Or something like that.

Reply 5 of 8, by DaveJustDave

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Interesting. I wish i still had my NEC Multisync 🙁

I guess without the right monitor there's no way to test. I wonder if those CGA/EGA to VGA adapters would support this video mode.

I have no clue what I'm doing! If you want to watch me fumble through all my retro projects, you can watch here: https://www.youtube.com/user/MrDavejustdave

Reply 6 of 8, by theoryboy

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I just happen to have these things on the table, and decided to try out Ironman super off roads, 64 color ega mode.
With my CGA/EGA to VGA converter it can sync to it, but looks like it does not have the colour sampling depth to get the full range of those colours.
In the pic attached I show the my pics vs one I found online and you can see limitation of my converter.

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Reply 7 of 8, by DaveJustDave

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interesting though.. it's still noticeably different from EGA

theoryboy wrote on 2021-01-25, 22:18:

I just happen to have these things on the table, and decided to try out Ironman super off roads, 64 color ega mode.
With my CGA/EGA to VGA converter it can sync to it, but looks like it does not have the colour sampling depth to get the full range of those colours.
In the pic attached I show the my pics vs one I found online and you can see limitation of my converter.

I have no clue what I'm doing! If you want to watch me fumble through all my retro projects, you can watch here: https://www.youtube.com/user/MrDavejustdave

Reply 8 of 8, by pan069

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What exactly is the relationship between EGA at 64 colors and a Multisync monitor? I.e. why would the monitor make any difference in the ability to display 64 simultaneous colors on EGA?

Edit: Somehow I missed the link provided by Horun to the vcfed forums. Interesting stuff.