Custom Resolution for EGA

Discussion about displays and related hardware including MiSTer filters and video settings.
chrisgetrich
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Custom Resolution for EGA

Unread post by chrisgetrich »

I am using the analog io board vga port.

What would be the custom resolution settings to support my monitor?

; custom mode: hact,hfp,hs,hbp,vact,vfp,vs,vbp,Fpix_in_KHz[,hsyncp,vsyncp]

Here are the specs I need.
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FoxbatStargazer
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Re: Custom Resolution for EGA

Unread post by FoxbatStargazer »

Uh is 1.5 to 4 volts the RGB level? Getting that out of Mister's 0.7 might be interesting....

Anyway they suggest 640 x 400 @ 60hz so maybe try that first. I use this site to generate.

video_mode=640,16,64,80,400,3,6,8,20000

In general you are probably going to need to hover around 400p for 60hz, which could be awkward with so many 224p cores. (you can make the horizontal resolution basically whatever you want up to 2056 as long as you got decent horizontal blanking settings) Maybe you can stretch it to 448p playing around with the blanking settings yourself though.
chrisgetrich
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Re: Custom Resolution for EGA

Unread post by chrisgetrich »

I was able to get a picture on my wells k7500 crt in EGA mode using the settings you described.

video_mode=640,16,64,80,400,3,6,8,20000

Thanks!
chrisgetrich
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Re: Custom Resolution for EGA

Unread post by chrisgetrich »

I checked vga output measured at pins for gnd and vsync at 25khz on the oscilloscope.

In case anyone needs their MisterFpga to output to an EGA crt thIs line in the settings.ini file works.

video_mode=640,16,64,80,400,3,6,8,20000

You can now use Misterfpga on your Medium Res EGA crts.
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