Scored my very first JAMMA pcb today. A good ol' Neo Geo board, I'm guessing it's an older model, looks a lot bigger than most of the boards pictured in this forum. Only one cart slot, too. Anyways, I would like to construct a simple video converter so I can use a VGA monitor/TV. I don't need a full-on supergun, as I was able to rescue the power supply from the old cabinet, also. I don't need audio or controller ports either: this board has controller ports, and two stereo outputs (one for speakers, one for headphones). I can wire the board for power and sound no problem, but I'm sorta scratching my head where it comes to extracting usable video. Any help would be muy mucho appreciated. Thanks!

Appreciate the tip. I'm actually looking to build some kind of adapter rather than buy one, but that board is pretty reasonably priced. Have you used it yourself? Is it a good one?


I wonder what would happen if I just soldered a VGA cable into the JAMMA wiring harness, red to red, green to green, blue to blue, ground, etc, and then just wired the two synch wires on the VGA to the one synch wire on the JAMMA harness? That couldn't cause any damage, could it? I've been researching this solution on Google and on this forum, doesn't seem like anyone is rolling their own adapters, but rather using storebought. Once again, thanks!

By the way... I salvaged all of the buttons and both joysticks, along with their wiring harness and attatched switches. I have no use for it, I'd be willing to sell it but I'd rather trade/partial trade for something to hook the board to VGA.

Well, looks like I'll need a full-on "supergun" arrangement after all. Checked out my arcade power supply, and it was shot. Packed full of so much dust, I probably could have grown crops inside it lol. I think what I would prefer to do would be to scavenge a PSU from a desktop or something and use it along with a VGA converter of some kind, but I'm pretty limited with resources right now. I'm serving a year long tour in Korea, and there's not a nice healthy supply of junk on this little bitty base. So, since I'm forced to order everything online anyway, guess I might as well order the whole thing in one piece. I've heard that not all superguns are created equal, but as yet I wouldn't know a good one from a bad one. I'd appreciate it if someone who's worked with them before could recommend a good setup. Here's what I want: VGA output, (component will do, VGA preferred) 12, 5, and -5v power supply, and uhhh... that's it, I suppose. I prefer to use the controller ports and audio from straight off the motherboard. Oh, and did I mention it needs to be cheap? (Under $100) I'll be doing my own research, but before I go and buy something, I'll ask y'all's opinion on the product, if you don't mind. Thanks!

Well, might be a moot point for you now but actually yes I do have one of these adapter boards. I bought one a while back to play around with. They work pretty well for what they are, though they don't actually do anything to improve image quality. Just convert it to VGA. Here's mine running Mario 64 on a RGB modded N64:



I haven't tested all the other input methods, only RGBs. On RGBs it seems to not like higher resolution input. I have to blind select games from the 64 Drive menu because the 64 Drive boots to a 640x480 resolution. It might just not like whatever its getting though. I'll have to do further testing in the future when I'm not so busy.

RGB N64, nice! Plan on sticking in a JAMMA cabinet or something?

Actually not a moot point at all. I've learned a lot about these Neo Geo boards since I picked this one up, and now I'm running the whole thing off 5v. Maybe one day I'll build a full-on "supergun" rig so I can mess with other JAMMA boards (TMNT!!!) but for now, I'm stuck in a military dorm room with barely enough work space and light to even do any decent soldering lol. Anyway, I ordered one MVC game online, it just arrived today, but a few days ago, this -awesome- local (Korean) arcade owner gave me a copy of King of Fighters 99 and King of Fighters 2004 for absolutely free, but -only- after he had meticulously cleaned them both and tested them on one of his working machines, during peak business hours. Needless to say, I brought him a six pack next time I came to play some games! Long story short, all three games seem to run just fine on my hand-me-down board. All I get is sound, (hooked it up to a stereo, it sounds incredible) but I have ordered a video encoder. Not one of the nice, VGA out ones, just composite, but it'll do for now. If all goes incredibly well, I just might end up with one of those sit-down "candy" cabinets to rebuild. Wish me lots of luck with that one! Anyhow, around the 11th or 12th, I should have some pics of an ugly, but working "consolized" MVS 1F.

Bummer... Having a base exercise all this week (pretending to be at war with North Korea and running around in chem gear) so the post office will be closed! Can't pick up my vid encoder. Dang North Koreans. They don't want me to finish my arcade console because this is what they're working with up there... http://www.ukresistance.co.uk/2008/09/i ... rcade.html

Sad face...

Anywho, some time next week. And then pics.

If want the cheapest option, a surprisingly large number of newer LCD monitors can actually sync to 15kHz horizontal (what the Neo Geo and many other arcade boards output). Even monitors that don't list themselves as being capable of syncing that low in their manuals can sync to it(like my Dell S2209). My guess is that the chipsets are made flexible enough to be able to be installed in a variety of products, including TVs with RGB SCART in. VGA spec can use pin 13 as the C-Sync instead of H-Sync.

How good it looks depends on the monitor, some will stretch it poorly (there may be settings to help this) and try anti-aliasing it too much making it look washed out.

So I can just splice the C-Synch wire from my JAMMA harness straight to wire 13 on a VGA cable, and it will/might synch up and work? Nice. I just twisted the H and V synch wires from my vga cable together and soldered them to the c-synch on the JAMMA harness and got nothing.

Video encoder finally arrived today. It was real easy to install, just soldered five wires straight to the copper pads on the JAMMA edge. It's a cheap encoder, outputs composite and Svideo only. Haven't tried it with S vid yet, but with composite, it really looks like crap. But it works, and that's awesome. Just need controllers now. And a case, but the case will probably have to wait until I get back to the states. I can barely run a soldering iron in this dorm room, much less a table saw lol. I'll try Tom61's suggestion later, gotta borrow a multimeter to determine what wire goes to the right pin. Thanks for all the interest and advice. I'll get some pictures up eventually, that is if anyone is interested in seeing this decidedly ugly mess. I'll get it nice and neat once I get back to my proper workshop!

Edit: I tried the encoder with a S-Video cable and now it looks perfect! I'm home sick tonight, so I went ahead and wired up a quick 'n' dirty controller using one of the joysticks and around half the buttons that came with the motherboard. Literally soldered the wires from each button straight to the JAMMA edge connector. Why?? Meh, I dunno. I don't plan on ever using a JAMMA harness on it again. Does make for a pretty fragile setup though. So here's what I'm thinking for a nice, custom joystick:

http://sonjeproductions.files.wordpress ... patron.jpg

Use that for an enclosure, I'll spraypaint the inside of the plexi with some black Crylon. Did that once for a boombox case mod. It ended up looking real nice, with the Patron logo standing out nice and sharp. Just gotta allow plenty of time between emptying the bottles and drilling the holes for the stick and buttons!