M81C SNES Kiosk S-Video?

[Esquire | 30]

I recently acquired two M81C SNES kiosks, and one of them came with the original JVC AV-2080S television. The consoles in these kiosks output RGB via JP-21 SCART to an AV board in the back of the unit. This board then directs the audio to the kiosk speakers while offering two video outputs: composite RCA and RGB from a 5-pin connector. For whatever reason, despite the JVC television having an S-Video input, the M81C is designed to make use of the composite signal. The 5-pin RGB output is instead used in the smaller M80C to output RGB to the infamous Zenith CD15MNTC1 monitor via a cable terminating in a DB9 connector.

So this got me thinking, is there a way to use the clean RGB output from the 5-pin connector to achieve an S-Video signal? The pinout of the connector is as follows:

• Pin 1: Red
• Pin 2: Green
• Pin 3: Blue
• Pin 4: Ground
• Pin 5: Sync

I could recreate the 5-pin IDC to DB9 cable used in the M80C, or I could potentially create a cable terminating in a EuroScart connector. However, I'm not sure how I could then go about converting this to an S-Video signal. Has anyone taken a stab at this before, or more broadly attempted to convert down from RGB to S-Video?

[Esquire | 30]

Kudos to @Bubbapauls for his guide on the SNES Kiosk Monitor Cable; been a big help in understanding the RGB output. He provided the following helpful image in another post. In it, you can see the pinout and the AV board in question:

Edited December 1, 2020 by Esquire

[koko | 65]

That diagram helped me a bunch when resoldering an RCA adapter so I could hookup the external 4 speakers to the kiosk but still run RCA video to my small 13" TV I use after my monitor broke.

Edited December 1, 2020 by koko

[drxandy | 3,225]

I don't know if you'd consider it, but rgb modding the tv (if possible) might be the cheapest, however I understand wanting to keep things stock.

http://m.axunworks.com/RGB-to-Composite-S-Video-p341706.html

[Esquire | 30]

RGB modding the display is certainly an option, but this particular model is apparently quite rare; intended for business applications like hotels and hanging store displays. I don't think I'll be able to find another one any time soon, so I'll probably settle for the nearly identical JVC AV-2070 for the second kiosk. That model is missing the slanted speakers on the sides and is limited to composite input. Not nearly as rare, so once I have one, it'll be a good candidate for an RGB mod.

As for converting RGB to S-Video, that device does seem like it would handle the task. While there's plenty of space in the back of the M81C, it would be nice if there were a smaller, less feature-rich device to handle the task. A passive converter would be ideal, but from what I'm seeing, that doesn't seem to be what I'm looking for. There is a cheap two way passive converter available on Amazon, but I bet that one simply supplies composite video quality through the S-Video connector.

I'll look around for some more powered converter options. I should be able to mount one to the inside of the kiosk and then just route the power cable through the same hole that is provided for the video cables.

[koko | 65]

If you do what I did, you can use a regular S-video cable, and just run the red/white audio to the kiosk. It requires an RCA to Euro adapter that just needs a rewiring, then Euro to JP-21. It would be the same setup I did, but instead of the yellow RCA running to the TV you would have the S-video cable while the audio goes to the kiosk to come out the external speakers. I forgot to do a follow up but it works perfectly now.

SNES Kiosk - using external sound with replacement TV - General Collecting Discussion - Video Game Sage

At least this is what I think you are trying to achieve unless I misread.

Edited December 1, 2020 by koko

[Esquire | 30]

Interesting. So you're just routing the audio to the AV board with a RCA audio -> EuroScart ->JP-21 SCART connection, then bypassing the board entirely to deliver composite RCA video to your television? That could certainly work.

The AV board in the M81C is the same as the one found in the M80C, but I've seen some boards in the later that are populated with RCA connectors and some that are not. In your case, it should be possible to add the RCA composite functionality to your board, allowing you to connect the same way that I am now: SNES -> JP-21 SCART -> AV Board -> RCA -> TV.

[drxandy | 3,225]

Nice @koko !! that totally makes things much easier, wouldn't have thought to avoid the video part of the board haha.

[LaC | 104]

Yeah I would be very tempted to mod this for RGB as the M80C RGB monitors look way better in comparison.

 

 

 

[koko | 65]

36 minutes ago, Esquire said:

Interesting. So you're just routing the audio to the AV board with a RCA audio -> EuroScart ->JP-21 SCART connection, then bypassing the board entirely to deliver composite RCA video to your television? That could certainly work.

The AV board in the M81C is the same as the one found in the M80C, but I've seen some boards in the later that are populated with RCA connectors and some that are not. In your case, it should be possible to add the RCA composite functionality to your board, allowing you to connect the same way that I am now: SNES -> JP-21 SCART -> AV Board -> RCA -> TV.

Correct. So in theory, every regular snes cable is useable, RCA or S-video, which bypasses the issues of the special cart cable entirely. It keeps the kiosk and tv's totally stock, and all cables are just stock cables as well. All you need are the adapters which are plentiful from any chinese seller on ebay. The only tough thing to find is the JP-21 to Euro adapter which I got from a UK seller. I just had to desolder and resolder a few pins to reverse the connection on the RCA adapter. It took me 2 minutes with zero soldering skills.

Edited December 1, 2020 by koko

[koko | 65]

36 minutes ago, Esquire said:

 

Yea my board does not have the RCA outputs on the back of the A/V board. When I was looking for a way to hook up a small crt after my monitor died, I saw some boards had them and was pretty discouraged lol. If you still wanted an S-video setup without modding anything, the way I did mine should work fine for you after getting a standard s-video cable for the back of the SNES. Video goes straight from the SNES to the TV, audio red/white goes to the kiosk board with the adapters. I guess technically you could also use an HD Retrovision cable for component if a TV had it, which would be comparable to RGB as well. Here is the adapter if I recall correctly after some searching:

EuroSCART to Japanese 21 pin JP21 adapter ntsc rgb21 (retrogamingcables.co.uk)

Super nice guy to work with. Just message him if you go this route to make sure. It's been almost a year since I've tackled this project and the RCA adapter just had to be reversed, output/input.

Edited December 1, 2020 by koko

[LaC | 104]

2 hours ago, koko said:

Correct. So in theory, every regular snes cable is useable, RCA or S-video, which bypasses the issues of the special cart cable entirely. It keeps the kiosk and tv's totally stock, and all cables are just stock cables as well. All you need are the adapters which are plentiful from any chinese seller on ebay. The only tough thing to find is the JP-21 to Euro adapter which I got from a UK seller. I just had to desolder and resolder a few pins to reverse the connection on the RCA adapter. It took me 2 minutes with zero soldering skills.

 

This adapter was such a good idea! Right?

[koko | 65]

Definitely worked out well  Just have to find a way to be able to mute it for silent play for when the kids are playing. I think running an extension out the back where the audio can be disconnected for muted play is next. I also want to eventually put a reset button in for the console outside so a flash cart can be used and anyone can just reset the cart by resetting the console without having to lift the plexi and risk snapping it. Those are future problems though, I'm still struggling to find time to finish my current 2 display projects lol.

Edited December 1, 2020 by koko

[Esquire | 30]

I'm going to try ordering a RCA to EuroScart connector, then rewiring it for JP-21; at least the audio pins. Should help keep things a little tidier in the back of the kiosk.

@koko For the M80C with side speakers, there should be a potentiometer for adjusting volume right above where the console is sitting. The board for this is found inside the back enclosure cover, next to the reset board. There should be a cable running to this board such that you can't fully remove the back cover without disconnecting it. If the kiosk doesn't have side speakers, you should find a flathead screw on the side for adjusting volume. Are neither of these the case for you?

[koko | 65]

My version has the speakers on the side at the bottom for 4 total speakers on the kiosk. There is a volume inside next to the timer. Unfortunately the knob inside doesn’t lower the volume to zero, you can still hear the sound even with it down all the way. It makes sense I suppose as the store would never want the kiosk muted. 

[Bubbapauls | 250]

On 11/30/2020 at 11:25 PM, Esquire said:

Kudos to @Bubbapauls for his guide on the SNES Kiosk Monitor Cable; been a big help in understanding the RGB output. He provided the following helpful image in another post. In it, you can see the pinout and the AV board in question:

I’m glad someone thought this was useful. When I had to fix my cable it was a pain to find any information about making another one.