RetroArch - Native CRT Support


Cool, let me know you finding. It will help me when it comes to creating porch settings.


Even though I’m using a CRT monitor, I don’t like to display SNES games at fullscreen (4:3). So, I normally use 320x240 with black bars to display SNES games (essentially using a 8:7 aspect ratio). Is it possible to do the same using this super resolution method? How?


For reference: this is what switchres gives me for neogeo:
"320x224x59.19" 6.650094 320 336 368 424 224 236 239 265 -HSync -VSync

and what gives retroarch:
"320x224_59.18" 5.44 320 328 352 352 224 229 232 261 -hsync -vsync

(reference for outsiders: string, pixel_clock, width, hfp, hsp, hbp, height, vfp, vsp, vbp)

And how my monitor does not like it:

I have to investigate more.


Hi @alphanu, first of all thanks a lot for this amazing implementation. As a fellow CRT enthusiast (I still own my beloved Sony Trinitron CRT I used to play on during my entire childhood and teenage years, still functional) I’m excited at the prospect of having RA work even more efficiently with that and outputting the best image quality for retrogames.

Now, I’ve never really dabbled in CRT Emudriver and based on what I gathered it seems to only work specifically with ATI/AMD cards. Do you have any advice with regards to getting this working with an nVidia card (I have a GTX 970) in a Windows 10 environment?


Hi @Ryunam

With Windows you are a big limited. These are metgeds of adding resolutuins but not always with success. The is an application called Custom Screen Utility that add reolutions to windows. When I used it I lost all my resolutions. So use it at your own risk.

The best way is Linux, it’s more accurate at emulation than windows as well. You can dual boot it with windows if you want. However, I just have a cheap second computer as my emulation machine running Linux. It’s only a core 2 due lol. But does the job great.

Hope this helps.


@vikbez Looking at the modeline I can instantly see one main issue. I’ll need to update that for everyone.

I’m just looking into it now as its an important bug to fix.

How are you outputting native in Linux? do you have a patched kernel? or are you using groovey arcade?


@vikbez I have edited the porches. This should fix the porching issue giving weird colors and incorrect hsp. You will probably still have over scan though.

download fresh or pull my git


I’m using a modified GroovyArcade distribution. I will try this in 4-6 hours.


@Alphanu the last nightly for Windows is perfect.

One last question, is there any difference between video drivers ?, gl, dx10, dx11?.


I tested your patches: modeline given is now .
"320x224_59.18" 6.224730 320 344 364 403 224 229 232 261 -hsync -vsync

and monitor is now black when switching resolution


I have been updating the src all day, Even now there has just been a few changes. I have it working on a B&O MX4000 and a crappy old TV too. I do have a Sony PVM in the other room which I will test on but I cant do that until tomorrow.

Try the src now if you can, the mode line should come out to be “320x224_59.18” 6.224730 320 336 358 390 224 229 232 261 -hsync -vsync



Works perfectly now !


just testing something - no reply/response needed.


Sorry about the ‘test’ post; I made a long post earlier today but it seems to have disappeared. Anyway, here we go again. Sorry in advance if I somehow inadvertently double post.

Hi @Alphanu. I’m sure you’re very busy but I was hoping you could help with a couple of things:

  1. I tried the latest nightly - hoping to fix that bug - but now when I run RA in fullscreen, my TV seems to be losing sync, possibly. The screen either goes blank or, very occasionally, I get two images side by side. I tried using exactly the same RA.ini settings as the 1.7.2 build(which works ok) but still the same issue. Any ideas what could be causing this? Side by side image. That 2.00Hz set reported refresh rate looks odd…

  2. Under RA 1.7.2, all PS1 and N64 games run perfectly. However, I’m having issues with mame, snes9x, Fuse, and ScummVM where the image is being squashed on the vertical. I’m guessing this is a scaling/ratio issue and might be related to games outputting anything outside of 240(and possibly 480) on the vertical, but I can’t seem to figured out a fix. Any ideas?

Castlevania running beautifully with Beetle PSX (SW not HW):

Bobble Bobble (Mame) squashed on the vertical:

Strangely, Rastan (mame) running at 256x240 seems to be fine:

Super Mario Kart (Snes9x) squashed - but I found a ‘fix’, see point ‘3’:

Renegade (Fuse) squashed:

Monkey Island (ScummVM) squashed:

  1. I’ve discovered a tiny, but slightly odd, issue with Snes9x, relating to the ‘Crop Overscan’ function. Running a game with Crop Overscan enabled or auto results in a squashed image:

If, while the game is still running, I change Crop Overscan to ‘disable’, and then ‘resume’, the image displays correctly, however it is lined up with the very top of the screen, leaving a small border at the bottom:

If, while the game is still running, I change Crop Overscan back to ‘enable or auto’, and then ‘resume’, the image displays correctly AND this time it is centered on the vertical with equal borders on the top and bottom. This is what I want, but cant figure out a way to get it without switching Crop Overscan when game is running:

  1. Just for the record, Groovymame seems to be running everything perfectly. An example of bubble bobble running at 256x224(2560x240p) :

  2. Do you know of any software I can use that will provide an onscreen overlay showing the resolution, vertical scan rate, etc.? If I can see what the emulator is outputting then I might be in a better position to figure out what’s going on and therefore solve my own problems…!

Thanks again in advance. Let me know if you need anymore info from me.



To start with this could be missing resolutions. For very low resolution games they are set in a resolution of [email protected] or @60 make sure this is installed. The game is then drawn at it’s correct resolution within this.

For snes, this is a bit confusing as it works fine for may others. However snes9x is not the best option in my opinion, use bsnes accuracy.

I need to update the Wiki @hunterk It was a necessity to change Retroarch menu resolution due to system clashes on Linux. In doing this there has been some changes and someone else added an edition which unfortunately broke the menu resolution. So in short this is fixed now but you’ll have to wait for the new nightly.

Puzzle bobble runs in 256x224 so you’ll need to make sure [email protected] or @60 is installed.

I’ll do some testing later when I’m home and check again your finding.

I have crop overscan on as default so this may be needed. Otherwise the core will report the wrong resolution and then won’t switch.


thanks for such a quick reply!

I’ve only got the default superres modelines that came with crtemudriver. I stupidly just assumed that these are all i would need with RA. I’ll make sure i install all the ones listed on your post in the CRT 15khz wiki page. I’ll give bsnes a go as well.

I’ll let you know my results later.


Make sure when you install the modes you choose static and not dynamic.


for most of the part, snes9x is running at 256x224, when overscan is used, it runs at 256x240.


@Alphanu @wertz

Thanks for your responses guys. Adding those additional modelines and running in static solved most of my issues, so thanks again Alphanu.

Fuse is still squashed on the vertical. I gather that the spectrum output 256x192, which i have installed as a modeline, so not quite sure what happening there. Any further suggestions?

Also, not entirely sure that ScummVM is displaying quite correctly - I vaguely remember something about these dos games running a vertically stretched 320x200 not a straightforward 320x240. I’ll have a fiddle around with it but for now its much better than what i had before.

I still can’t get over how epic playing all this old stuff is. As a kid, I never had RGB cables, and possibly not an RGB capable TV either, and so running all this stuff now via RGB is a real treat. Playing Castlevania SOTN nearly brought a tear to my eye it look so damn good!


@hunterk sorry and thanks for dealing with that post. It can be completely deleted if that’s more tidy.