CMVS and the OSSC

Balder

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I've been using my CMVS on my old TV directly through RGB scart, and it worked perfectly, however after getting a new TV that doesn't have scart inputs, I thought getting an OSSC would do the trick. Apparently I can fry the thing if I just use it directly since the voltage is too high. How can I go about this problem?

I've heard that getting a Genesis cable with a resistor inside would lower the voltage. I bought one of those and it doesn't fit my CMVS. The 8 pin layout looks the same, but these cables aren't interchangeable after all with my CMVS.

Tried posting this on reddit, but no one came to help. So now I turn to the experts.

There are someone on eBay selling very expensive component Neo-Geo cables. Would that work? He claims it fits both a MVS Supergun and the Genesis. So I'm a bit skeptical about spending 50 bucks on a cable that doesn't fit my CMVS.

Some people have suggested using the VGA port on the OSSC, but I haven't heard anyone actually testing that out.

Does anyone have any idea how I could connect my CMVS to my OSSC without it frying over time?

Here is some pictures of the CMVS, the port and the cable that came with it: https://imgur.com/a/21EQdQR
 

Xian Xi

JammaNationX,
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Most people just put a 470ohm resistor on the sync line.
 

Neo Alec

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Yeah, it's easy. You just solder the resistor on the sync line. Retrogamingcables should be able to sell you one that already has the resistor.

How do you know you need it? If you're already using the CMVS on a CRT, it's probably already properly attenuated.
 
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And other options would be a RAD2X cable like this guy on twitter uses:
https://twitter.com/turfmasta/status/1210622768942911488

I'm new here but I think it's the user @turfmasta on this forum. Maybe he can give you some more information. I would also be interested in what is between the JAMMA connector and the cable.

The rad2x is available for various consoles. In order to use it with a cmvs you would need appropriately attenuate your rgb signals and then wire them up for the pin out of the appropriate console you purchased a rad2x for. If you're looking for info on how to attenuate the rgb signals this should help

https://www.assembler-games.com/thr...nsolized-saturated-overly-bright-image.51917/
 

DeWitt

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Thank you very much!

It was a bit hard to read because of all the HTML code inside some posts but very interesting! To bad that all the schematic are not visible anymore...

Than I found this one here inside the forum: Consolized-MVS-RGB-from-JAMMA-(PCE-Amp-mod)

If I'm not mistaken the video part should work together with a RAD2x cable. Only sound needs to be added.
 

Balder

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Yeah, it's easy. You just solder the resistor on the sync line. Retrogamingcables should be able to sell you one that already has the resistor.

How do you know you need it? If you're already using the CMVS on a CRT, it's probably already properly attenuated.

I'm grateful for your response dude. I still have some questions if you don't mind. I contacted Retrogamingcables a week ago, and they told me that they didn't sell any cable that would work. I'm not sure if they took the time to understand my problem though. Anyways, could you take some time to see if this cable would work: https://www.ebay.co.uk/itm/SNK-NEO-...830730?hash=item288919558a:g:dyAAAOSwNddcjg6f

It says it has CSYNC and that it's compatible with the Neo-Geo AES and CD. Does the AES also have the 8 pin port like my MVS has?
 

Neo Alec

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If your current scart cable worked on your TV, I wouldn't worry about plugging it into the OSSC. Whoever built your CMVS should have already attenuated the signal. I'm not sure where you got the idea that your system is outputting too high of a voltage without measuring it.

Assuming your CMVS has the same video pinout as the AES, then the cable you linked or the standard Neo Geo cable from retrogamingcables would work. Not sure if they would be any different than the cable you already have though.
 

GohanX

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If your current scart cable worked on your TV, I wouldn't worry about plugging it into the OSSC. Whoever built your CMVS should have already attenuated the signal. I'm not sure where you got the idea that your system is outputting too high of a voltage without measuring it.

Some idiots who build CMVS's just tap the RGBS signal directly from the jamma edge without attenuating it, and the OSSC's sync line on the SCART input doesn't have sufficient protection from overvoltage. Any well built system shouldn't have any issues.

That said, a lot of these questions should probably be directed at whoever built the CMVS, they're the only ones that can really answer a lot of these questions.
 

Neo Alec

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Agreed. My point is if he's that worried about it, he probably shouldn't have been using the scart on the TV to begin with either if it's not properly attenuated.

Balder, if you've ever opened that CMVS, you should be able to see if a resistor is there on the sync line.
 

Balder

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I have no idea how to measure the voltage, and after watching some guides on how to open up the MVS and look for resistors are also not an easy thing to do it seems. Honestly at this point I think I'm just going to find a cable with a resistor and buy it. If you have any suggestions for a cable, that'd be great. I think the port on my MVS is called a c-style 8 pin din.
 

Neo Alec

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Wait... A CMVS that's difficult to open?
 

Balder

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Wait... A CMVS that's difficult to open?
Opening it is not a problem, but locating and checking that it's the right kind of resistor was not as easy according to the guide I read. Anyways, spending 20-30 bucks on a cable and never having to think about this again is worth it to me.
 

Neo Alec

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Google the AES AV pinout to find the sync line.. If there's any resistor at all you should be okay.

Take a photo.
 

Balder

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Maybe I have all of this turned upside down. There are virtually no-one selling a cable that I thought I needed. Perhaps I've misread or misunderstood that all of the CMVSs fries the OSSC. From now on I think I'm just going to play it with my OSSC and see what happens. Now I just need to change the settings and update the firmware for it to work.
 
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