240p120hz PC VGA CRT

Discussion about displays and related hardware including MiSTer filters and video settings.
Deezdrama
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240p120hz PC VGA CRT

Unread post by Deezdrama »

So Ive explored alot of various video ouput setting using 4k displays with 5x scaling, YPbPr 15kHz signals to consumer crt sets, and currently been playing with settings on a PC VGA CRT.
Scandoubling looks great but CRT FX 25% doesnt have defined enough scanlines for my liking, 50% looks good but the display is a little too dim, 75% looks awesome but neither of my 19" PC CRT monitors have the luminosity to punch through the dark lines and the image is just way too dim.
Ive tweaked the image pot on the back of the flyback but it just washes out the image. Not sure if my tubes on these two 19"ers seen alot of use and are just dimming from wear and age or if its normal for CRT FX 50% and 75% to dim the image this much.

If I use vga scaling and just use core filters the image is fine, nice and bright but doesnt look quite as sharp as scandoubling...


The last thing I havnt tried is custom video mode lines.
Ive used them before in the past with retroarch on a PC i setup to output a 15kHz signal using crt-emudriver and the results were good but took a while to setup.
Ive read about using a single custom modeline that is kind of a generic "close enough" for all cores but will cause shimmering due to not being an integer of native resolutions for all cores.

Is it better to define a custom modeline for each core? Is this even possible and an option?
Ive read alot about the duplicated frames of 240p120 causing a strobe affect without black frame insertion but Im not sure if BFI is even supported yet on mister and even if it is- I dont want to use it due to the dimming effect Im already trying to get away from.

Is it feasible to have a mister setup using 240p120hz and custom mode lines for all console cores? Any issues of doing this?

I guess its just more of a curiosity at this point, to at least try it once on even just a single core to see how it looks and decide if I like it.
Any quick testing mode line suggestions?


If I start adding custom mode line settings to my ini is it possible to run into corrupted ini issues? I guess I could just make a backup before I begin.

Any other tips/thoughts/suggesstions?

Thanks!

******EDIT********

I got it all figured out and holy crap its AMAZING!!!!
Heres a quick vid I made...

thorr
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Re: 240p120hz PC VGA CRT

Unread post by thorr »

Sounds like a fun, yet dangerous experiment. You could fry the flyback or something else while experimenting. You may or may not get it to work at all, but if you do, I have my doubts it will change the look very much. VGA monitors are not as "bright" (I use that term loosely) or bloomy as TV's. I was devastated when my large VGA monitor stopped working, but it was a blessing in disguise because I prefer using CRT TV's for almost everything and found this out after getting them after the monitor died. They just look better and more authentic. For ao486, I would prefer a VGA monitor, but for 320x200 and 320x240 games, it looks surprisingly amazing on a CRT TV.
Deezdrama
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Re: 240p120hz PC VGA CRT

Unread post by Deezdrama »

thorr wrote: Wed Nov 24, 2021 11:19 pm Sounds like a fun, yet dangerous experiment. You could fry the flyback or something else while experimenting. You may or may not get it to work at all, but if you do, I have my doubts it will change the look very much. VGA monitors are not as "bright" (I use that term loosely) or bloomy as TV's. I was devastated when my large VGA monitor stopped working, but it was a blessing in disguise because I prefer using CRT TV's for almost everything and found this out after getting them after the monitor died. They just look better and more authentic. For ao486, I would prefer a VGA monitor, but for 320x200 and 320x240 games, it looks surprisingly amazing on a CRT TV.
Nah, only thing i tweaked was the image pot on the flyback a hair just to get a little more brightness so it didnt have to be maxed out in the displays menu.
And 240p120 is basically the same thing as scan doubling .... except your doubling vert freq from 60hz to 120hz instead of horiz freq from 15kHz to 31kHz

Im just looking for suggestions on a modeline/s to use.

And yeah, Im just testing the PC VGA CRT out, ultimately a 27" sony fs120 will live on the mister
Deezdrama
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Re: 240p120hz PC VGA CRT

Unread post by Deezdrama »

Deezdrama wrote: Thu Nov 25, 2021 12:00 am
thorr wrote: Wed Nov 24, 2021 11:19 pm Sounds like a fun, yet dangerous experiment. You could fry the flyback or something else while experimenting. You may or may not get it to work at all, but if you do, I have my doubts it will change the look very much. VGA monitors are not as "bright" (I use that term loosely) or bloomy as TV's. I was devastated when my large VGA monitor stopped working, but it was a blessing in disguise because I prefer using CRT TV's for almost everything and found this out after getting them after the monitor died. They just look better and more authentic. For ao486, I would prefer a VGA monitor, but for 320x200 and 320x240 games, it looks surprisingly amazing on a CRT TV.
Nah, only thing i tweaked was the image pot on the flyback a hair just to get a little more brightness so it didnt have to be maxed out in the displays menu.
And 240p120 is basically the same thing as scan doubling .... except your doubling vert freq from 60hz to 120hz instead of horiz freq from 15kHz to 31kHz

Im just looking for suggestions on a modeline/s to use.

And yeah, Im just testing the PC VGA CRT out, ultimately a 27" sony fs120 will live on the mister after i recap and adjust yoke this winter.
FoxbatStargazer
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Re: 240p120hz PC VGA CRT

Unread post by FoxbatStargazer »

I have tried 240p/120hz and the high refresh also increases the intensity. So it completely solves the dimming problem, and delivers a much sharper look than the scandoubler. You aren't really increasing the horizontal refresh any, still around 31khz, so I don't think it should wear the guns out significantly. Maybe more the phosphers along the scanlines.

I just used this site to make modelines: https://tomverbeure.github.io/video_timings_calculator

You can feed it 240p/120hz and it will give you timings you can build the modeline from. You can use something ultra wide like 1920 to not have to worry about matching up the resolution to each core, just change aspect ratio to full and it will look right on a CRT.

The tricky thing would be trying to exactly double the refresh rate, so you can get your original output perfectly aligned. That mostly comes down to adjusting the pixel clock to the right value and the site I listed doesn't let you enter fractional refresh. Otherwise its going to be slightly off and cause a little variable lag, which is all I could get working. You are stuck with vsync_adjust=0 anyway so there is always going to be a tiny bit of lag added.
thorr
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Re: 240p120hz PC VGA CRT

Unread post by thorr »

FoxbatStargazer wrote: Thu Nov 25, 2021 1:06 am I have tried 240p/120hz and the high refresh also increases the intensity. So it completely solves the dimming problem, and delivers a much sharper look than the scandoubler. You aren't really increasing the horizontal refresh any, still around 31khz, so I don't think it should wear the guns out significantly. Maybe more the phosphers along the scanlines.

I just used this site to make modelines: https://tomverbeure.github.io/video_timings_calculator

You can feed it 240p/120hz and it will give you timings you can build the modeline from. You can use something ultra wide like 1920 to not have to worry about matching up the resolution to each core, just change aspect ratio to full and it will look right on a CRT.

The tricky thing would be trying to exactly double the refresh rate, so you can get your original output perfectly aligned. That mostly comes down to adjusting the pixel clock to the right value and the site I listed doesn't let you enter fractional refresh. Otherwise its going to be slightly off and cause a little variable lag, which is all I could get working. You are stuck with vsync_adjust=0 anyway so there is always going to be a tiny bit of lag added.
This is the one I use almost exclusively: https://www.epanorama.net/faq/vga2rgb/calc.html
It allows you to see the refresh rate as you adjust the numbers.

Why are you stuck with vsync_adjust=0? Is that a limitation of the analog board or something? I am using the HDMI output and converting it to component from there and can use vsync_adjust=2.
FoxbatStargazer
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Re: 240p120hz PC VGA CRT

Unread post by FoxbatStargazer »

If you want to push 120hz to the monitor but your cores are 60hz, you can't just pass the core's original refresh rate along! So you have to use vsync_adjust=0 to let the scaler buffer the extra/doubled frames.
Deezdrama
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Re: 240p120hz PC VGA CRT

Unread post by Deezdrama »

FoxbatStargazer wrote: Thu Nov 25, 2021 1:06 am I have tried 240p/120hz and the high refresh also increases the intensity. So it completely solves the dimming problem, and delivers a much sharper look than the scandoubler. You aren't really increasing the horizontal refresh any, still around 31khz, so I don't think it should wear the guns out significantly. Maybe more the phosphers along the scanlines.

I just used this site to make modelines: https://tomverbeure.github.io/video_timings_calculator

You can feed it 240p/120hz and it will give you timings you can build the modeline from. You can use something ultra wide like 1920 to not have to worry about matching up the resolution to each core, just change aspect ratio to full and it will look right on a CRT.

The tricky thing would be trying to exactly double the refresh rate, so you can get your original output perfectly aligned. That mostly comes down to adjusting the pixel clock to the right value and the site I listed doesn't let you enter fractional refresh. Otherwise its going to be slightly off and cause a little variable lag, which is all I could get working. You are stuck with vsync_adjust=0 anyway so there is always going to be a tiny bit of lag added.
Yeah i just checked back and seen all the replies lol, I was busy testing out bahn yuki's (youtube) modelines that he got from mike chi and vsync adjust=0 and setting aspect to full on each game....... Holy Crap...... STUNNING!
This is probably the best ive seen mister to date and i tested several cores including arcade and all were jaw dropping!
I was starting to wonder if my tube was going out because everyone running scandoubler with 50% and 75% CRT FX and sounded happy but it was too dim for me even after flyback pot tweaks.
Well running in 240p120 definitely lights them phosphors up and I finally get that bright luminance "crt glow" ive been craving on this monitor!
Couple that with those dark scanlines and its like a perfect example of a CRT or a nice PVM, I dont notice any shimmering or frame doubling strobe either..... Just an amazing image! But there is a con and its the input lag. Its not horrible but definitely notice it. Ill have to test more on some games I usually use to judge input lag and whether or not its too bad for me to not be able to ignore.
But for image quality..... Im highly impressed and glad I took the time to explore this option!
thorr
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Re: 240p120hz PC VGA CRT

Unread post by thorr »

Cool! What modeline did you end up with?
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Malan
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Re: 240p120hz PC VGA CRT

Unread post by Malan »

I'm not a fan of 240p 120hz... It causes a ghost image while scrolling (very noticeable in Sonic games).
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Re: 240p120hz PC VGA CRT

Unread post by FoxbatStargazer »

I'm coming around to 270p@100hz to deal with PAL stuff like Amiga. Computers rarely used both smooth and fast scrolling and its so much better than the 50hz flicker on a VGA monitor.
Deezdrama
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Re: 240p120hz PC VGA CRT

Unread post by Deezdrama »

thorr wrote: Thu Nov 25, 2021 7:16 am Cool! What modeline did you end up with?
Deezdrama
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Re: 240p120hz PC VGA CRT

Unread post by Deezdrama »

Malan wrote: Thu Nov 25, 2021 9:12 pm I'm not a fan of 240p 120hz... It causes a ghost image while scrolling (very noticeable in Sonic games).
Ive found no visual artifact issues with the modelines mike chi and bahn yuki use.
I just finished a video...
https://youtu.be/P3t3Wi7eQ0g
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Malan
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Re: 240p120hz PC VGA CRT

Unread post by Malan »

It's not really an artifact, it's just how high refresh rate works with low framerate. You have the same effect while playing 30 fps games on a 60Hz CRT. If you don't notice it, don't bother and enjoy it :)
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Re: 240p120hz PC VGA CRT

Unread post by FoxbatStargazer »

120hz is fast enough you probably won't see "artifacts", at least on slow-scrolling games. What you will see is a slight motion blur that reminds you of an LCD panel, wheras scrolling that matches a CRT's refresh rate shows zero blur at all, same as if the screen was still.

So in short this means you are trading off two advantages of CRTs, the motion blur and input lag, to get some razor sharp scanlines that approximate a PVM. It does look really good on static content but it undermines a bit why people usually game on CRTs in the first place instead of flat panels, and its inching closer to just using a great scanline filter on a flat panel. I do recommend trying it out if you haven't but ultimately don't find myself using it much.
Watari
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Re: 240p120hz PC VGA CRT

Unread post by Watari »

240p180hz can also be used if your CRT supports it. Artifacts are even less visible than in 120hz and there is less input lag.
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