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Nodoyuna

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Hi,

I've seen a couple posts about 31KHz to 15KHz connections and, as I have my own doubts about it, so I'm opening a new thread

What a want is to connect my emulation computer from VGA to PVM monitor, and also, for connecting original PCB's too, like Naomi...

Right now, I'm using an UMSA interface from ArcadeForge

Lately, I'm becoming a real fan of Extron products, so I'm wondering If there is some Extron interface I can use to connect my VGA devices to the PVM in the best possible quality

hanks in advance
 
you mean without conversion / scaling right?

Any Extron Crosspoint switcher should be able to do it.... they support pretty much everything as input or output.. like RGBHV (VGA), RGBS, RGsB, Composite, S-Video.. whatever.

You just need to take care that the input matches with the output (or add scalers in the chain)
 
without downscaling..PC GroovyMame running at 15khz and Naomi setup to 15khz..what I use = Extron 203 RXi. If your Sony monitor supports above 15khz you can run the PC and Noami at the supported kHz like 24 or 31.
 
Yes, I'm looking for a solution without downscaling, just a device to Connect 31KHz to 15KHz monitor
I'll try the Extron 203rxi
 
your sentence can be a little bit misleading.. you can't output 15khz from a 31khz input without downscaling.

What you can do is to output RGBs (for example SCART) from a RGBHV source (= VGA), but the souce frequency needs to be always supported by the output device.
 
Yes, I'm looking for a solution without downscaling, just a device to Connect 31KHz to 15KHz monitor
I'll try the Extron 203rxi
If your monitor can display 31khz, but only has a classic 5pin connector (R,G,B,sync,ground) you could use a Extron 580i to composite the H and V syncs safely.
I guess some of these style chassis do exist in the wild?
I would suspect the image would be dark without some amplification on the RGB lines due to 5pin connector expecting JAMMA levels of power?

The thing you seem to be failing to understand is IF that monitor is truly a 15khz monitor it won't display a 31khz input.
That's why we have dual syncs (15/24khz) and tri-syncs (15/24/31khz)... But not me cuz CRTs are dead man *snicker* anyway... ;)

CGA=15 EGA=24 VGA=31 you can think of it like this.
Each format is different, and needs to be supported by the monitor if no scaling/conversion is used.
the souce frequency needs to be always supported by the output device.
Hey you said it using less words, no fair. :D
 
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Hi

What I have is a PC with the CRT Emudriver installed on the VGA output

If I use a VGA to SCART cable to Connect this output to the 15KHz monitor, the image does have interference lines

Then, I tried the UMSA device, and that's how I use It now, but the output image IS mostly blurry, so I think there should be a better method to get the BEST output

So, is there such a device?

Thanks
 
What is your PVM model? As long as you have CRT emulator out putting to 15khz you will be fine with the Extron that I mentioned..

On my PVM 20L5 --> RGB output connected to BNC cable RGB and black sinc --> going to Extron --> VGA cable going to PC running GroovyMame CRT emulator at 15khz.. most of what I play is 15khz.
 
The PVM I have is the 2530 model with SCART input
Are You familiar with this monitor?
 
That one is 15khz only.. on crt emulator you will need to set up to 15khz.. I am not sure if that monitor had no problems combining the sync so you might want to try a Cable with a BNC to one end and a VGA on the other end. If that does not work then the Extron..the Naomi you will have to set it to 15khz and connect to the Extron.. anything 31khz like Xbox 360 you will need a downscaler to conver 31khz (Xbox 360) to 15khz so your monitor will see that.

Edit - that monitor has the RGB pins (25 or 31) and no BNC RGB.. you might need a special cable and maybe retro console accessories can make one for you with one end for that special pin and the other end for BNC so it can go into the Extron.. you might need to switch between your RGB consoles and the Extron or get a gscart switch with VGA output that can go into the Extron but that will cost you like $200
 
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Oh, sorry, I made a mistake with the monitor model

The one I have is the PVM 2730QM

Sorry for the confusion
 
What I was reading is that the monitor should accept 31khz..but I am not 100% sure since I am not familiar with that monitor..could you take pictures of the inputs on the back to see what input it takes?
 
I have a 2730QM. It's 15khz only. There are no BNC connectors at the back for RGB, however, there's a scart connector that accepts it.
 
if you are using a PC you can soon also consider using a VGA 31khz monitor to use 240p without any added device.

Some of them are cheap and almost same quality as high end PVM or BVM.

I always thought a 31khz couldn't do 240p, but I was wrong, it depends also on the refresh rate.

If you play emulation, you can double the refresh rate from 240p60 to 240p120 a 31khz monitor can show 240p with proper scanlines.

The trick to make 240p enter the range of 31khz is to use an emulator that can handle double frame, or black frame insertion. It does 120 frames / s instead of 60 frames /s either by sending twice the same frame or adding a blank frame. The second solution creates a dark tint because half of what you see in a second is a black frame.

Retroarch will soon integrate 31khz 240p option, as Ben Templeman is working on that solution.

I guess the same can work with Groovymame but I haven't experienced this yet.

https://www.youtube.com/watch?v=TGmLRuHFvRM
 
The trick to make 240p enter the range of 31khz is to use an emulator that can handle double frame, or black frame insertion
Yup double striking beams with black frames inserted will do the trick.
I still wouldn't really say its 240p tho, because naturally 120 fps isn't spec.

It's always personally strange to me when people strive so hard for proper refresh/sync/output on a emulation setup...
But I guess to each his own? :huh:
 
It's 240p120 instead of 240p60, yes it's out of spec, but as long as the emulator can handle this it shouldn't be a real problem. It's like the super resolutions, you can't notice you are on 2560x240 because the emulator multiplies the width by an integer number.

it's the same effort to maintain correct refresh but double frames for each second, as long as it's integer it shouldn't harm, emulation can handle this because it can send 2 shorter frames from 2 instances of the same game at the same time to fit instead one normal frame, the eye couldn't say the difference, you always see a game that has 30fps content. Real hardware is another problem because it has to create the frame then duplicate it so 1 frame of lag at the minimum...

I won't be surprised that some day emulation could offert less lag than the real thing.

I am on the real hardware route if you ask me, I prefer one monitor for each thing, I enjoy more the real experience because it's authentic, and it's probably related to childhood memories, but I always find interesting when emulation don't just mimic but offer new ways to do things.

Pushing our cheap 31khz monitors to 240p120 is one of the things I find very good when you see the increasing price of trisync solution when it comes to emulation.
 
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