Rotating a vertical arcade core on a CRT TV?

[HappehLemons]

Before you jump on me here, I read:
viewtopic.php?t=1462
It was explained that this CAN'T be done.

However, this guy (https://youtu.be/RmcqiU_vKPA) seems to get it working no problem with this adapter:
https://www.radioshack.com/products/hdm ... er-adapter

Has anyone done this before? Can anyone share if there's certain settings that need to be enabled for this to work properly?

[lister_of_smeg]

That thread states that rotating the *analogue* output of the MiSTer can't be done - this is an important distinction. What the poster of that video is doing is converting the MiSTer's *digital* output (which can be freely rotated in the core settings) to analogue using that adapter.

Also, from the comments section of the very video you linked:-

@Esben Hardenberg In this video the screen is rotated on my composite input. I'm using MiSTer's HDMI out to a Radio Shack HDMI to Composite adapter.
Radioshack converter:
https://www.radioshack.com/products/hdm ... er-adapter
https://studio.youtube.com/video/_DFcNxaS4G0/edit
I'm using video_mode=6 in the mister.ini
6 - 640x480@60
Later I discovered video_mode=2 looks better on my TV.
2 - 720x480@60
[MiSTer.ini]
forced_scandoubler=0
composite_sync=0
vga_scaler=0
YPbPr=0
direct_video=0
SOG Switch - N/A (on or off didn't make a difference)

The key is setting the MiSTer output to something the adapter/converter is expecting as input (from the product information: 480i/480p) which is why video_mode=2 (or video_mode=6) is required.

[zorrobandito]

Great question, diplomatically posed.

I'm quite interested in this topic too. It's the feature that's preventing me from converting my CRT MAME cabinet to MISTER. The thought of walking away from those great vertical shooters...<sob>

I bought a cab with a 26" monitor so I could run vertical games without losing too much in the process and groovymame is a pretty good approximation.

Of course, if this was possible, I'd have to review what sort of fidelity compromises were being made...

[caad]

It's not going to look awesome, due to the maximum 240p resolution (horizontal in a vertical shooter). You'll get terrible aliasing artifacts. I'm in the same boat really, and have decided I will need to build another cabinet later...

Alternative: get a VGA monitor.

[akeley]

I use Groovymame on my other CRT and it does the rotation fairly well. Still, the real thing looks so much better, so if you're realy into arcade games on a CRT the only answer is to have two separate setups.

[DevilHunterWolf]

The rotation option in the arcade cores is implemented for the digital HDMI output only. It doesn't function for analog signal output since the analog out is meant to be the original output of the arcade board, console, etc. The adapter from that thread is really an HDMI to Composite converter. The MiSTer isn't doing anything different to the HDMI signal like what happens with the Direct Video setting. The "adapter" has a chip inside it to convert the digital signal into the analog signal for composite output. These kinds of converters are available all over the place. The problem is they're meant for people to watch their movies and TV through it, not play retro games. Some of them have a significant amount of added latency. There are some that will have very little or next to no additional lag but that's not what they're manufactured for. They can be hit or miss for retro gaming. But since it's straight taking the HDMI output from the MiSTer, that's why the rotation worked for them. It wasn't using actual analog output from the MiSTer itself.

Now, you can have the MiSTer output to Composite, Component, SCART, and VGA and still use rotation. You have to use the vga_scaler=1 option. What that does is have the VGA connector on the IO board mirror the output of the HDMI. The downside of this is you're no longer at native resolution and frequency of the core you're using. You also have to be aware not to set too high of a resolution or the image won't fit or display so a little more playing around with settings may be in order. And since you're going through the scaler, you're *technically* adding additional processing. Though, the amount of latency added is so little that it qualifies as "no lag". But if someone was trying to play on a CRT and have both horizontal and vertical games working on it without actually putting the CRT on its side, then the VGA Scaler is the option to try. It just probably won't look as good seeing as it will be scrunched into the middle with a lot of empty space on the sides.

[HappehLemons]

Awesome information everyone. Thanks so much for the breakdown here.

[HappehLemons]

The rotation option in the arcade cores is implemented for the digital HDMI output only. It doesn't function for analog signal output since the analog out is meant to be the original output of the arcade board, console, etc. The adapter from that thread is really an HDMI to Composite converter. The MiSTer isn't doing anything different to the HDMI signal like what happens with the Direct Video setting. The "adapter" has a chip inside it to convert the digital signal into the analog signal for composite output. These kinds of converters are available all over the place. The problem is they're meant for people to watch their movies and TV through it, not play retro games. Some of them have a significant amount of added latency. There are some that will have very little or next to no additional lag but that's not what they're manufactured for. They can be hit or miss for retro gaming. But since it's straight taking the HDMI output from the MiSTer, that's why the rotation worked for them. It wasn't using actual analog output from the MiSTer itself.

Now, you can have the MiSTer output to Composite, Component, SCART, and VGA and still use rotation. You have to use the vga_scaler=1 option. What that does is have the VGA connector on the IO board mirror the output of the HDMI. The downside of this is you're no longer at native resolution and frequency of the core you're using. You also have to be aware not to set too high of a resolution or the image won't fit or display so a little more playing around with settings may be in order. And since you're going through the scaler, you're *technically* adding additional processing. Though, the amount of latency added is so little that it qualifies as "no lag". But if someone was trying to play on a CRT and have both horizontal and vertical games working on it without actually putting the CRT on its side, then the VGA Scaler is the option to try. It just probably won't look as good seeing as it will be scrunched into the middle with a lot of empty space on the sides.

However, it seems like when I try this method my CRTs display results in a distorted flickering picture. Is there a custom video mode I should be using here? 640x480 60hz is the lowest video mode offered and this does not seem to display a functioning picture on my CRT TV.

I've tried other members video modes like:
video_mode=352,26,34,73,240,4,3,15,7383

However these don't work properly on my TV and I have no idea how to calculate a version that works for the CRT TV (NTSC)

[DevilHunterWolf]

I didn't think it applied when vga_scaler=1 is set, but try also setting forced_scandoubler=1 in the ini as well. That sets the analog out connections to 31KHz instead of the typical default 15KHz. If the TV can't handle the 15KHz, then perhaps the 31KHz signal will do the trick. If you do have forced_scandoubler=1 already, then try turning it off and see if the opposite is true. But I thought the VGA Scaler overrode that setting.

If that doesn't work, then I can only think the picture is too big to fit in the range of the TV. I don't mean that as in resolution but as the size adjustment of the picture in the TV's menu. I only have Composite input TVs so I was using a VGA to Composite converter. Since each core is different, I'd have to use the adjustment buttons on the converter to move and resize the picture to be more center. If I made the image too big and too far over the edges, the picture would start flickering until I shrunk it back within the view of the CRT screen. There's no auto adjust like many LCD screens can so it has to be done by hand.

What are you using to connect the MiSTer to the CRT? What connection type on the TV are you plugging into?

[HappehLemons]

Actually, I've gotten pretty close now, but still having 1 last issue.

I'm hooked up directly to component thru the VGA port with ypbpr=1 and vga_scaler=1

Using:
video_mode= 320,8,32,40,240,1,8,6,6120

I get almost get the exact result I'm looking for, but for some reason the right side is cropped off:

4HskgyE.jpg (2.51 MiB) Viewed 5009 times

With:
video_mode= 640,76,60,118,240,4,1,20,14200

I get a thinner result, but the image is super thin, with the same issue of the right side is cropped off

5iasQqC.jpg (1.51 MiB) Viewed 5009 times

Any idea

1) What the proper pixel ratio is here (1st or 2nd image)?
2) Why they're both giving me the exact issue of cutting off the right side of the image?

On the OSD dashboard, the image is perfectly centered and is not cut off at all.

While I'm pretty much just copy and pasting things here, I know this tool was used to make these video modes:
https://tomverbeure.github.io/video_timings_calculator

However I have no idea how to use it.

[DevilHunterWolf]

I'm not sure what to make of that. It almost looks like you'd need to resize the picture in the TV's menu, but maybe not with all that empty space. It is also interesting when you changed the horizontal resolution from 320 to 640 that it stretched out the vertical picture, though. I wouldn't have expected that.

I'm definitely not an expert in this situation but it looks like the core trying to stretch to fit the screen isn't working with the settings you're using. I'd recommend trying to dial in the resolution of the TV in the ini to make sure that's good first. After that, I'm curious if turning on integer scaling (vscale_mode=1) would help. If the core is stretching to fill the screen incorrectly because it thinks the screen is somewhere off the side of the picture, then maybe telling it to use the exact scaling would fix that? Could be worth a try just to see what happens.

[HappehLemons]

I'm not sure what to make of that. It almost looks like you'd need to resize the picture in the TV's menu, but maybe not with all that empty space. It is also interesting when you changed the horizontal resolution from 320 to 640 that it stretched out the vertical picture, though. I wouldn't have expected that.

I'm definitely not an expert in this situation but it looks like the core trying to stretch to fit the screen isn't working with the settings you're using. I'd recommend trying to dial in the resolution of the TV in the ini to make sure that's good first. After that, I'm curious if turning on integer scaling (vscale_mode=1) would help. If the core is stretching to fill the screen incorrectly because it thinks the screen is somewhere off the side of the picture, then maybe telling it to use the exact scaling would fix that? Could be worth a try just to see what happens.

This didn't seem to do much for me. I ended up posting in the display form as I hope someone who understand the workings of CRTs & mister scaling might be able to help:
viewtopic.php?f=33&t=3527

[DevilHunterWolf]

This may not be related to the issues you were having, but I did notice something odd that I thought I'd mention. I've been putting together a vertical monitor build and found issues with certain versions of the core files. The Arcade Organizer in the update_all had all the vertical monitor games put together under the rotation category so I was initially picking from there. Then when it came to use it in my build with the OSD rotated, they stopped displaying on any LCD; even my more compatible ProArt. I picked a core from the main _Arcade list of them all together and they worked. Maybe this is something weird from me copying over from another MiSTer, maybe the organized version is an alt of some kind since it has clockwise and counterclockwise versions, I don't know. I thought they were just straight copies of the same core files but there was *something* different with them. It may be worth keeping in mind in case there's a difference that's getting in the way.