Using Neo Geo (and JAMMA stuff in general) w/ old Amiga/Commodore monitors?

[Fayk]

So I think my old Commodore 1950 might actually still work - this isn't just NTSC like an 1080 but I think is 15KHz, etc capable. What is required to use something like this with arcade hardware? Any active hardware, or just a passive cable/correct wiring? I think the (captive) cable it has built in is a DB15 (like normal VGA).


Similar question for something like a 1080/1084? Those are just NTSC/PAL, right? But I think they took direct RGB? Are the cables to hook these up at all standard? Does anyone make these, rather than everyone just making their own?

 

[Kyuusaku]

There is no standard for signal level or impedance matching in arcade video so it's hard to really say if it'll "just work", it really depends on how forgiving the monitor is. I suspect such old monitors which expect TV-level signals are not very forgiving because they probably won't have automatic gain control like many TVs do. Building an AGC input stage (and auto-termination) is hardly feasible which is why most people rely on attenuation potentiometers which for the most part work well enough. You can however fairly easily build an active buffer for sync to make sure the monitor is delivered the appropriate level, but most people wouldn't bother with that either as the sync input is likely already robust enough to handle it as-is. I guess what I'm saying is "just try it".

 

[Yodd]

1080/1084 are analog RGB capable monitors. You will need to use a custom cable as Commodore over the years used different connectors for the analog RGB port. Some 9 pin female, others male, sometimes a 6 pin din connector. Pretty much mix and match. You will need to build your own cable regardless. Nice thing is that these monitors except composite sync so most low res boards should work fine. Might need a sync stripper in some cases to help clean up the sync signal, but otherwise should be pretty smooth sailing.

The 1950 should be capable of supporting both 15KHz and 31KHz stuff as its a multisync monitor. However it's fault prone and I am unsure if its capable of composite sync or if it needs separate H+V syncs.


Either way, between the commodore models, generally the 1084 is the best option. Plus the 'S' models have stereo speakers.

 

[Fayk]

Thanks both of you for the answers. For the 1950 I was asking Simply because I still actually have one - as for a 1084(S), I had one long ago, but if they would work well, I'd try to get one again if I could find one nearby in decent condition.

 

[Yodd]

Thanks both of you for the answers. For the 1950 I was asking Simply because I still actually have one - as for a 1084(S), I had one long ago, but if they would work well, I'd try to get one again if I could find one nearby in decent condition.

To be honest, since you are in the Bay area, I personally would look for something like a 13/14 or 20 inch Sony PVM. You should be able to get a 20 inch model for well under $100. Just make sure you get a model that has RGB inputs via BNC connectors. At this point all those old Commodore monitors from the later 80's are starting to fail or at very least have a short life span left on them before needing to be serviced.

I would get an RGB capable PVM. Very nice monitors for Arcade board usage.

 

[darthv72]

It's nice that this topic has been brought up. i recently dusted off my 1084s and I have several systems and RGB cables for them. I have the Jaguar, SNES and old and new genesis and each has their own RGB cable for the 9pin D sub on the back of the monitor. I had (at one time) an AES and it too had an RGB cable but that was then. I have the Neo CD and from the look of it, the A/V port is very similar to the old genesis.

I tried my RGB cable in it and while it was a tight fit (i believe the pin spacing is slightly different) i got nothing but jumbled picture. I did a look up on the pinout and it looks like they are the same so I couldnt really tell why my genesis rgb cable didnt work. I tried it on the genesis and it works. I may have to just build my own again as perhaps it has something to do with the pin spacing and the genesis being a "U" shape instead of the Neo "C" shape. Stress on the pins and whatnot.

Anyone got an idea?

 

[Fayk]

I tried my RGB cable in it and while it was a tight fit (i believe the pin spacing is slightly different) i got nothing but jumbled picture. I did a look up on the pinout and it looks like they are the same so I couldnt really tell why my genesis rgb cable didnt work. I tried it on the genesis and it works. I may have to just build my own again as perhaps it has something to do with the pin spacing and the genesis being a "U" shape instead of the Neo "C" shape. Stress on the pins and whatnot.
Anyone got an idea?

I am NOT the person to ask (just replying hoping more people will look at the thread to help you) because I don't understand any of this stuff (yet?), but I suspect the pinout is entirelyt different (aside from whether trying to use a U in a C or vice-versa is a bad idea) - I don't think there was any industry standard.

http://www.gamesx.com/avpinouts/neoav.htm vs http://www.gamesx.com/avpinouts/genesisav.htm

 

[darthv72]

Thanks Fayk. Yeah Ive used that site before. Funny thing is while they show the different views for the Neo-Geo (male/female) I can only tell that the view that show on the Genesis is male. When pairing them up, the Neo-Geo male view matches the Genesis view. What i dont have is a Genesis regular A/V cable set to verify the basics of the composite out on the Neo-Geo CD. I dont even know if the composite and audio are even hooked up through this port considering there is already a dedicated set of A/V ports on the back of the CD.

It would be nice if someone who has either the AES or CD can confirm that the A/V port is wired up the same as the Genesis. Then it comes down to the physical shaping of the pins themselves. U vs C.

 

[Yodd]

They both have identical pinouts, however the Megadrive uses a 262 degree U shaped 8 pin din where as the Neo uses a more standard C shaped 270 degree 8 pin din. If you force one into the other, you risk bending/breaking the pins or worse; destroying the port on the console.

My guess why it isn't working - Either the pins aren't making proper contact since they are being bent to fit into the RGB port, or your monitor doesn't like the sync from the Neo CD. I have heard of XM29's monitors not liking the sync signal from the Neo CD and needing an LM1881 circuit inline to filter and clean up the sync. Its possible that the 1084 isn't liking the sync from the Neo CD unit as well.

Some pics or video of what is happening would help.

 

[darthv72]

thanks Broken. I will say that my genesis cable has a little 9 pin to 9 pin extension on it that has some sort of little chip inside to clean up the signal when its connected to the genesis. If i were to take that off and plug the genesis in it doesnt look right. So maybe it could be as you say. the pins are not making a good clean connection because of the shape of the genesis connector.

I dont want to break the cable or the port so I will just wire up a new set of cables for it. It has been 20 years since I did anything like that but I want to get serious about using my cd unit more. Aside from getting a working RGB cable I have read and watched the procedure to do the language mod on it. Mine is a JP unit and i want to switch between US and JP and the mod looks really easy.

 

[dragonpt]

They both have identical pinouts, however the Megadrive uses a 262 degree U shaped 8 pin din where as the Neo uses a more standard C shaped 270 degree 8 pin din. If you force one into the other, you risk bending/breaking the pins or worse; destroying the port on the console.

True, but i use the same cable for my megadrive 1 and NeoGeo CD/MVS, i was never able to find the 8 din "C" shaped ...

you can see the differences on both 8 dins here:

http://www.mmmonkey.co.uk/console/sega/md-stereo-scart.htm

On the Neo i have to push hard a bit, but works flawless

 

[Yodd]

True, but i use the same cable for my megadrive 1 and NeoGeo CD/MVS, i was never able to find the 8 din "C" shaped ...

you can see the differences on both 8 dins here:

http://www.mmmonkey.co.uk/console/sega/md-stereo-scart.htm

On the Neo i have to push hard a bit, but works flawless

You are doing it wrong. You shouldn't be using that connector with the Neo. You risk damaging it or the console's RGB port. I know the differences between the two and I know you are using the wrong connector.


The C shaped 8 pin din is very common. If you can't find one, you aren't looking very hard. The C shaped is by FAR the most common one.