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MDA/CGA/EGA to VGA Converter Released!

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Reply 60 of 331, by Plasma

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Here is a simple color test program I made, along with screenshots from my LCD with the converter. The colors look the same on my CRT. (The top pic looks a little washed out, but that's just my camera.)

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Reply 62 of 331, by keropi

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currently downloading the quartus program, such an annoying way to get it!
I will report back after programming

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Reply 63 of 331, by keropi

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Allright - after an annoying process to download the Quartus software I updated my board - can't say I saw much improvement though. I took some pics at an angle as they show better the color tones I am actually seeing - monitor was reset to factory defaults

VO2zphfm.jpg lt8b6XPm.jpg RM7FHFPm.jpg

FURXCVTm.jpg ud8DmJam.jpg ISfnNycm.jpg

last pic is from CGACAL : http://www.oldskool.org/pc/cgacal

This requires more investigation.

I was also able to test MDA/Hercules modes with a clone card that I had no idea if it was working or not until now 😀

zJQvGYGl.jpg

edit:
I seem to have lost the "fine tuning" feature , pressing reset does nothing now

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Reply 66 of 331, by Plasma

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Hmm well you shouldn't be using my pictures as an absolute reference. They obviously aren't proper VGA captures just pictures of my monitor, and the exposure of the camera isn't constant. I thought the colors looked ok on mine before but I updated with the latest code. To be honest I don't notice a difference (the OSD is nice though). But I took some more screenshots with both EGA through the converter and VGA directly to the monitor. It looks pretty close to me.

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  • ega1.jpg
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    ega1.jpg
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  • vga1.jpg
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    vga1.jpg
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  • ega2.jpg
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  • vga2.jpg
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    vga2.jpg
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Reply 67 of 331, by keropi

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retrocanada76 wrote:

check if you have the very last update. I updated the code few hours ago. I fixed the bright levels compared to plasma screen.

I do, used the one with the comment "Adjust color brightness"

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Reply 68 of 331, by retrocanada76

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Plasma wrote:

Hmm well you shouldn't be using my pictures as an absolute reference. They obviously aren't proper VGA captures just pictures of my monitor, and the exposure of the camera isn't constant. I thought the colors looked ok on mine before but I updated with the latest code. To be honest I don't notice a difference (the OSD is nice though). But I took some more screenshots with both EGA through the converter and VGA directly to the monitor. It looks pretty close to me.

I have a 286 VGA to use here as reference. I will try it as I don't use it.

If you look to the code, I am not propagating the bits to bits 0 and 1. I think this is much closer to what should be. In essence the normal should be half bright as the brighter ones. That wasn't the case.

The OSD is not the only difference. You have much more freedom to adjust the screen, before it was 16 pixels only, now is 127px

Reply 69 of 331, by carlostex

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I need this in my life. I have a CGA Turbo XT and a Tandy 1000 that would love some testing.

So from what i understand this issue only affects EGA? Or is there some problem with the color decoding that will affect all video modes?

Plasma shots look good to me.

Last edited by carlostex on 2018-01-31, 14:06. Edited 1 time in total.

Reply 70 of 331, by Plasma

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The colors are fine on the original 2.0 PCB design. I have sold around 20 kits using that PCB and no color issues were reported.

Some of dreamblaster's prototypes appear to have color problems. I'm not sure what the cause is or if CGA is affected.

Reply 71 of 331, by RobertJ

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Amazing work!

8-bit Collection: 4 64Cs, 6 1541-IIs, 1 C128, 2 1571s, 1 C128DCR
Vintage DOS: Dell Optiplex G1, AMD Rage IIC, Sound Blaster CT4520, Thrustmaster FCS Mark II, Gravis PC GamePad
Monitor: Dell 20" 2007FPb

Reply 73 of 331, by keropi

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retrocanada76 wrote:

The last FPGA code changes CGA mode to 720x480@60Hz. It shows a nice border around the image just like the CGA CRT.

that's great news! is 60hz also supported on EGA mode?

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Reply 74 of 331, by retrocanada76

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I don't know what good resolution at 60Hz to use. Look, I can't use 720x480 or you would get shrunken pixels and lose 28% of real state screen vertically. Do you think that 60Hz much more important than aspect ratio and dumb narrow images ??

The only resolution rather than 640x350@70Hz it 720x400@70hz. All the other will look like crap. And it must be supported by standard VGA monitors. I can't ge the 1280x768@60hz and double the lines like I do for CGA.

https://www.mythtv.org/wiki/Modeline_Database
http://martin.hinner.info/vga/timing.html

Reply 75 of 331, by keropi

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I wasn't referring to the high-res 640x350 EGA mode, I should have made clear I was referring to low-res 320x200 stuff 😀
So with the new update one could play for example Commander Keen EGA on the new 720x480@60Hz mode?

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🎧Orpheus soundcard project
💻WTB Amstrad PC7486SLC-33 system

Reply 78 of 331, by NJRoadfan

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retrocanada76 wrote:

The only resolution rather than 640x350@70Hz it 720x400@70hz. All the other will look like crap. And it must be supported by standard VGA monitors. I can't ge the 1280x768@60hz and double the lines like I do for CGA.

1280x960 is the closest VESA mode, but that is going to require some padding on the line doubled output resulting in black bars. Even then it won't look right as 640x350 isn't a square pixel resolution while 1280x960 is. One would need to really adjust their v-size control to get results similar to a VGA card running EGA mode graphics.