My two-game adapter - howto and do you want one?

[stratjakt]

I've sucessfully built a circuit/setup that let me put my Playchoice 10 and VS Super Mario boards in the same cabinet, and toggle between the two with the tap of a momentary pushbutton.

Unlike Clay's multi-jamma kits, which have every board powered at all times, my circuit trips a DPDT relay to route 12V and 5V to the appropriate board.  This part of the circuit can be found here http://ourworld.compuserve.com/homepages/Bill_Bowden/page9.htm

The relay I used was overkill, rated for 15A at 30V, but I'd rather "over engineer" power related stuffs.

Originally, I wired the relay circuit and just tied all other lines together, and while it worked, the video came up poorly.  Plenty of smearing on the PC10 side, and the VS was blurry. 

In one of Bob Roberts articles, he mentioned using diodes (he said 1n4007's) in a two-game setup.  This absolutely did not work (I kind of knew it wouldnt but did it anyways).  The 0.7v voltage drop was too much, it was barely visible.

So, I turned to the CD4066 chip, which is a "quad bilateral switch with low on resistance".  These are commonly used in the cheaper video switching units (the 20 dollar remote controlled s-video switches from hong kong), it's basically 4 switches in a chip with 100 ohms of resistance when "on". 

I used two chips, running RGBS from each board into each chip, and the outputs tied together.  If you look at the circuit above, I used the Q output to "activate" all four switches of one chip, and the not-Q output for the other.  This works like a charm, and the video looks crisp and fantastic.

At this point, it works, and I'm happy with it.  The VS is somewhat louder than the PC10, so I'm thinking of adding a couple of 10k log pots to the audio lines, so I can adjust them to roughly the same level.  Jamma boards with their own built-in amps and volume controls wouldn't have this problem.

While this all works, it's a friggin' mess of perfboard and wires.      I'm in the process now of drawing up a PCB to house all of this, with nice mounted disconnects, basically to be cleaner and more professional.  I was planning on photo-etching it and doing it all by hand, but sooo many holes to drill.  I was looking into some of the online board-creating solutions, and thinking I might go that route.

Which brings me to my ultimate question.  If I were have a bunch of boards made up, would anyone be interested in one?  I'd basically just provide the nice silkscreened, drilled, and solder masked PCB and a parts list (nothing esoteric, all cheap common stuff). 

I know I want at least two (one for my neo-geo/hyper neo geo cab, one for my PC10/mario).  The more I make, the cheaper each board is.  I'm not trying to make any money, just make it cheaper on myself.

I'm also looking to design a newer version, that could switch more than two boards - right now based on the chips I'm planning on (an up/down decade counter with decoded inputs) would give me 10 boards.   That's still a ways down the road.

Anyways, let me know if you'd be interested in either project.  Clay's system is nice, and certainly more suited to a commercial setting, but this is a much cheaper way to pull it off at home.  120 bucks for his main board, plus 20 per adapter, not to mention all the extra power supplies to keep the games running..

[okayama]

Well how much money are we talking about for a home version?

[RayB]

Is it "plug n go" or requires some hacking/rewiring?
I might be interested if the price is right (I could get Galaga 88 running in my Galaga!)

[arcadefever]

i will like to get 3 to 4, just let me know how much , and can you post a pic
thanks

[Dave_K.]

Unlike Clay's multi-jamma kits, which have every board powered at all times, my circuit trips a DPDT relay to route 12V and 5V to the appropriate board.  This part of the circuit can be found here http://ourworld.compuserve.com/homepages/Bill_Bowden/page9.htm

So whenever you switch games the current board looses power and the switched to board then powers up?  This doesn't sound very convenient if you switch between games often.  You may want to look at Mikes'd Double Jamma adapter as a better comparison design:
http://mikesarcade.com/cgi-bin/store.pl?sku=DBLJAMMA

[CheffoJeffo]

So whenever you switch games the current board looses power and the switched to board then powers up?  This doesn't sound very convenient if you switch between games often.

I dunno .... depends on the boards involved, I think.

First, I need to say that I own one of Clay's MultiJAMMA kits and LOVE it (and the power supply deal is really a non-issue).

I am looking to put  JAMMA switch kit into my NAOMI GD-ROM showcase (figure I'll add a PC-based system to it for emulation/TV/jukebox) and was looking to keep costs down. At the end of the day, however, any solution that doesn't maintain power to the NAOMI system is a waste of time ... no way I want to sit and endure a full GD-ROM reboot whenever I want to play Virtua Tennis 2. Clay's gonna get another MultiJamma order for that one.

I also have a JAMMA countertop that I would like to install at least two games in (currently thinking Rygar and Tetris) and be able to switch easily and cheaply between them. stratjakt's solution may be a good option there as they both boot pretty darned quick.

Cheers.

[Dave_K.]

I am looking to put  JAMMA switch kit into my NAOMI GD-ROM showcase (figure I'll add a PC-based system to it for emulation/TV/jukebox) and was looking to keep costs down. At the end of the day, however, any solution that doesn't maintain power to the NAOMI system is a waste of time ... no way I want to sit and endure a full GD-ROM reboot whenever I want to play Virtua Tennis 2. Clay's gonna get another MultiJamma order for that one.

Well if you are only switching between two games, Mike's adapter is both simpler and cheaper than Clay's since you don't need the extra power supply.  Mike's powers both at the same time, and no need to even rig a special "switch" button on your control panel, just press P1+P2 at same time to switch back and forth between games.

[stratjakt]

Depending on the games you used, powering each board seperately isn't a big deal at all, vs boards take about 2 seconds to get to the title screen, the PC10 about 5.

I didn't want to go to the hassle and expense of any of the existing solutions, since for one, neither board is Jamma.  Also, the P1 and P2 start thing wouldn't have worked for me, since when the PC10 is up, "P1 and P2 start" are mapped to game select and game start, and could concievably be hit at the same time, really easy to do if you're playing Tyson's Punch Out and are blindly smacking for the uppercut. 

Plus, I like to make stuff myself.  Last I checked, this was a DIY forum, so quit hatin' on me for not wanting to throw money around.  I'll build/hack my own RGB-composite adapters, video amps,  led drivers, and usb encoders too.  Take your iPacs  and jPacs and fudgepacs and shove 'em.  You can pick up a genesis at a thrift shop for 5 bucks and salvage the RGB-composite encoder, or you can spend 100 bucks on JROC's  (or build an equivalent for the cost of a 10 dollar IC and some spare parts).

But I digress...

Ultimately it was the cost issue.  The cost of either clay's or mikes setup turned me off, I'm not made of bucks, and there's so much arcade-related stuff I'd rather spend my cash on.  Hell, the money I saved not buying Clay's or Mikes kit payed for the XMen vs Street Fighter cabinet I bought last week.

The whole "prototype" rig probably cost me about 25 bucks in parts, most of that being for the various edge connectors and the overkill-relay I used.

It's just messy as is, and I've always wanted to try out one of those online PCB services to make me a nice professional-looking product, and of course, the more you order, the cheaper each board becomes.  I'll have to actually finish the layout before I can know exactly what each board would cost, 20 bucks would be a number I just pulled out of ---my bottom---..  The more I have fabbed, the cheaper they'd be.  It'd be a DIY thing, I'd just resell the boards..

The rest of the components needed would basically be:

1x CD4053 Dual d-type flip flop
2x CD4066 Quad Bilateral Switch
A couple of capacitors, a couple resistors
A couple of transistors, a couple of diodes.. Nothing esoteric, like a couple of 2n3904s, 1n4001s
A DPDT relay (most expensive piece, the one I used was 7 bucks)
Some sort of headers to attach the board wiring, not sure exactly what I want to use, but I like the idea of 40 pin IDC sockets (ie; hacking IDE hard drive cables like Clay's)

Except for the IC's and headers everything could be got easily at radio shack (if you like paying 3 bucks for a transistor,  that is). 

I have some other ideas to modify the circuit board, I could easily modify it to take P1+P2 start - hell, I could put a jumper block to allow you to configure whatever button combo you wanted (ie; P2 start + P1 joystick down). 

I mentioned before possibly adding a place to tie audio pots to level out the volume on games that need it.  Perhaps two audio outputs - to allow to mix amplified/unamplified boardsets.

I guess I could throw over the relay, and just switch audio and the coin/start buttons with a couple more 4066's, or analog mux's since that's what Mikes essentially does (guessing from the pictures),  it seems to leave the rest of the inputs tied together.  Which wouldn't matter, nothing bad is going to happen knocking around the controls while a game is sitting in attract mode.  Essentially it would be Mike's adapter, but it would cost probably a quarter of the cost,  just more time.

Anyways, this was never a commercial "put it on route" solution, just a simple way to get multiple games in a cabinet.

I might even dive straight into a 3 or more multiple-board solution.

I just wanted to put some feelers out there see if anyone would be interested in joining me on a community-designed multigame switcher.  The electronics involved are really 8th grade level, it's just silly to spend 100+ bucks on one, in my mind.

So please no more "why would you do this instead of buying XXX" replies.  I'll respond to all such questions with "Why would you guys build a mame cabinet instead of buying an Ultracade?"

[stratjakt]

I was mulling it over during lunch, and I think when I go to actually get boards fabbed, I'll probably go the "all powered at once route", and adding a relay to route audio.  The problem I see with Mike's unit is both boards attached to a single power supply, which may not be ideal, since there are lots of really power hungry boards out there.  I'd definately want to add jumpers to drive "daughter" circuits - notably switching stereo audio, or powering relays to activate different lighting (ie; a neato dual-marquee that lights the selected game, not unlike a Neo Geo cabinet)

Anyhoo, it's still in the design phase, anyone has any ideas or can think of anything I'm missing, let me know.

Coin lockouts might pose a problem for cabinets and games that use them.  What happens if the game locks out the coinbox, then you switch..  That'd sucksy.

CheffoJeffo:

I was thinking about your Naomi/PC hybrid too, since one day I'd like to build a Naomi/Atomiswave/Triforce/System246/Whatever hybrid.  Unless your already running through a JAMMA interface board, and are in love with CGA video and monaural sound, I don't think any of these solutions would be all that ideal..   

If it were mine to do, I'd probably look into hacking a cheap KVM switch - using it to route the VGA from each, and it'd be easy to tap a logic "off" and "on" following pin 4 of the PS/2 connectors (+5V), or elsewhare, to route the start/coin and audio through 4066 chips (IIRC, naomi has line-level audio, right?  If not, a relay for amplified audio).

[CheffoJeffo]

I was mulling it over during lunch, and I think when I go to actually get boards fabbed, I'll probably go the "all powered at once route".

CheffoJeffo:

Yes ?

[CheffoJeffo]

I am looking to put  JAMMA switch kit into my NAOMI GD-ROM showcase (figure I'll add a PC-based system to it for emulation/TV/jukebox) and was looking to keep costs down. At the end of the day, however, any solution that doesn't maintain power to the NAOMI system is a waste of time ... no way I want to sit and endure a full GD-ROM reboot whenever I want to play Virtua Tennis 2. Clay's gonna get another MultiJamma order for that one.

Well if you are only switching between two games, Mike's adapter is both simpler and cheaper than Clay's since you don't need the extra power supply.  Mike's powers both at the same time, and no need to even rig a special "switch" button on your control panel, just press P1+P2 at same time to switch back and forth between games.

Was thinking about this some more and, for the NAOMI system and a PC system, it doesn't matter to me if the switch powers the boards or not ... both have their own power supplies ... doh!

Cheers.

[stratjakt]

lol, reread my post..

I fatfingered and saved it before I was finished.

[Goz]

I am looking to put  JAMMA switch kit into my NAOMI GD-ROM showcase (figure I'll add a PC-based system to it for emulation/TV/jukebox) and was looking to keep costs down. At the end of the day, however, any solution that doesn't maintain power to the NAOMI system is a waste of time ... no way I want to sit and endure a full GD-ROM reboot whenever I want to play Virtua Tennis 2. Clay's gonna get another MultiJamma order for that one.

Well if you are only switching between two games, Mike's adapter is both simpler and cheaper than Clay's since you don't need the extra power supply.  Mike's powers both at the same time, and no need to even rig a special "switch" button on your control panel, just press P1+P2 at same time to switch back and forth between games.

Was thinking about this some more and, for the NAOMI system and a PC system, it doesn't matter to me if the switch powers the boards or not ... both have their own power supplies ... doh!

Cheers.

Given the nature of the power needs of the NAOMI 3.3v, etc and the extra kick needed for the GD-ROM you definitely want separate PSU's. both PC and NAOMI being VGA is a beautiful thing as stratjakt hit on the nose.... KVM is really all you need. You can run the PC audio into RCA's and into the NAOMI sound amp with some Y connectors as well.

[Rocky]

Unlike Clay's multi-jamma kits, which have every board powered at all times, my circuit trips a DPDT relay to route 12V and 5V to the appropriate board.

[stratjakt]

Didn't need -5v, if I wanted it, though, I could have easily added another relay, or found a TPDT, I'm sure such things exist.

The "production" model will have it, it'll power the boards seperately, and a bunch of other stuff that this one doesn't have.

Note that Clay's MultiJamma doesn't have -5v either, from what I can see, it uses PC power supplies and their 4 pin molex connectors, just 5 and 12.  I'm sure it could be wired on. -5v isn't used by all that many games, I suppose.

[CheffoJeffo]

Note that Clay's MultiJamma doesn't have -5v either, from what I can see, it uses PC power supplies and their 4 pin molex connectors, just 5 and 12.  I'm sure it could be wired on. -5v isn't used by all that many games, I suppose.

Clay's kit does indeed have -5v, but not on the connector for PC power supplies (for the obvious reason). There is an 8 pin header as well for use with boards that draw lots of current or require -5v.

Cheers.

[gsoul]

I know I'm a complete electronics IDIOT.. but could the following technically work?



So all the Jamma connectors go into a terminal strip then into another jamma connector, then all you're effectively doing is turning on or off each board ie cutting it off from the power.

[RayB]

You might need some electrical part that stops current from flowing in the wrong direction, and put on on each and every wire coming from each JAMMA board... otherwise in the end, wouldn't something like a video signal "bleed" out to the 4 other video connections that are attached (though unpowered)??

[gsoul]

I'd be VERY interested in your proposed Multi-board project.

I've been trying to get my head around this whole topic, but it seems you've got it setup.

I'd basically want a 6 - 8 way switcher.

Post or PM me and let me know how close you are to working this out, alternately, give me a hand to build my own kit and between the two of us we might be able to improve the design.

[fredster]

Good work Electronic wiz dude.

A do it yourself kit would be great.  I'd like to try that.

See if you could come up with a kit that has all the parts, and I'd like to get one from ya.

[slycrel]

I hate to bring up a dead topic...  but has this gone anywhere?

[red_johnny]

I'd be VERY interested in your proposed Multi-board project.

I've been trying to get my head around this whole topic, but it seems you've got it setup.

I'd basically want a 6 - 8 way switcher.

Post or PM me and let me know how close you are to working this out, alternately, give me a hand to build my own kit and between the two of us we might be able to improve the design.

I am with you.  I would love to see a kit that would allow me to have 6-8 game boards.

[CheffoJeffo]

Not sure what happened to stratjakt, but there is always the MultiJamma.

Some other MultiGame/Switchers are listed in the wiki.

[BobA]

There a alot of 2 in 1 adapters being made off shore.  I have heard pros and cons for some of them but they are fairly cheap. I have not tried any of these myself.

http://www.arcademvs.com/ARCADE_ACESSERIOR.htm

[red_johnny]

Yeah but I want a 4 or 8 to 1 adapter.  I am not ready to buy one just yet but for the project I am working on it will be very benefitial to have something like that to make my project worthwhile

[BobA]

OK just posted the 2 game adapter because that was what the thread originally covered.

Best multijamma adapters made are from http://www.multigame.com/jamma.html

If you can still get them.

[red_johnny]

OK just posted the 2 game adapter because that was what the thread originally covered.

Best multijamma adapters made are from http://www.multigame.com/jamma.html

If you can still get them.

Cool, I will check them out

[CheffoJeffo]

Best multijamma adapters made are from http://www.multigame.com/jamma.html

If you can still get them.

Getting them from Clay can be a slow process, but they pop up from time to time (2 here in B/S/T within the last month).

arcadefever seems to be the expert on finding them -- I've lost count as to whether he has picked up 2 or 3 kits since I have had mine.

[Arm123]

Hey stratjakt...

Great thread man !  I hope you keep us all updated on your progress.

[shardian]

Hey stratjakt...

Great thread man !  I hope you keep us all updated on your progress.

Sorry dude, but the guy is long gone. This thread is effectively dead.

[CheffoJeffo]

This thread is effectively dead.

It's not really dead as long as we keep the memory of it alive in our hearts ...