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Custom Resolution for EGA
Posted: Thu Mar 17, 2022 8:34 pm
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.
- crt.PNG (317.73 KiB) Viewed 1146 times
Re: Custom Resolution for EGA
Posted: Thu Mar 17, 2022 11:39 pm
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.
Re: Custom Resolution for EGA
Posted: Mon Apr 04, 2022 3:45 pm
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!
Re: Custom Resolution for EGA
Posted: Mon Apr 04, 2022 10:45 pm
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.