Building a multi-game switcher

Stuffmonger

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Well, I am wondering how to go about making a game switcher that would function well for a bunch of games (maybe up to 10). I have heard the 6 in 1 china switchers don't work all that well, and another that I've seen keeps all the games powered on at all times, which I don't want. So, what I'm thinking is, if I could wire up all my games together, only keeping the power sources on toggle switches so that whichever game I want to play, I turn on, and the others would all be off.

Would this work? Or, would having the boards' signal wires connected cause the signals (video, controls, etc) to deteriorate?
 
It's going to mess with SOME of the signals. The problem is that the boards were made with the assumption that they had sole connection to everything, so the designers didn't worry about the state of drivers and inputs when powered down. Some boards will probably work great, others will cause you video trouble, still others will do weird shit to the control panel.

It may be that most boards will work great, I don't know.

If I was going to build such a beast, I'd find a way to switch ALL the lines from one board to the next with minimal loading.

From a signal integrity standpoint, the optimal situation would be to move the JAMMA connector from one board to the other - no extra loading on any lines. You want to come as close to that ideal as you can.

One way to do it would be a multi-position switch that had N leads. You'd wire all the JAMMA leads from each board to one of the switch positions, and then when you rotate the switch, you change boards. If you actually try this (I don't think you'll find such a switch) It's important to realize that you need a NON-SHORTING switch - that is, the switch MUST disconnect one board before connecting the next. Also, you'll have to be careful (and lucky) to avoid crosstalk between lines on the switch causing problems.

Realistically, you probably are going to have build circuit board with a bunch of muxes (multiplexers) and some control logic to select which set of mux inputs/outputs are selected. The muxes will keep the loading to a minimum, so the thing should work well. You'll need to be careful to choose the right sorts of muxes (input vs. output for each line), and I'd be real careful about where you run the traces on the board, and how you do shielding. If it was just a one-off, I'd probably put a tin shell around the thing, just for paranoia's sake.

You could also try it with a big stack of relays, but that seems like asking for trouble when one of them sticks somewhere down the road.
 
Or you could do what I'm playing with and run a jamma extension harness to each game board to under the flip up CP on my Gaunt Legends cab. Then have another Jamma extension harness running to the cab Jamma harness.

Switch games = turn power off, flip up top of CP (takes 1 sec because there's no need to keep it locked), swap cab jamma extension harness to game of your choice. Turn power back on.

No interference, no lost signals, in theory no issues at all.

You'll have to handle the kick harnesses (if any) as well. And use decent quality jamma extension harnesses.

So far I'm running this way with Gaunt Leg and NBA Jam and it works well for me. Probably going to add a 3rd board before too long but you could stretch it up to 10 if you wanted.
 
so, basically, I'd need something like this
http://www.westfloridacomponents.com/mm5/graphics/sw081a.jpg
except, with 10 positions, and 40 decks?

Yes, with the caveat that you need to make sure it's non-shorting, AND you have to hope that proximity of the lines doesn't cause problems (you can mitigate problems by positioning higher-speed signal lines like the video and audio in between ground positions). If you have trouble with video or audio, you might try mitigating by using shielded cable for those lines.

Note that you should probably run the grounds to everything all the time (don't switch them). But if you can afford the larger switch, I'd also put ground positions in between vid/audio lines on the switch to lower the likelyhood of problems.
 
Or you could do what I'm playing with and run a jamma extension harness to each game board to under the flip up CP on my Gaunt Legends cab. Then have another Jamma extension harness running to the cab Jamma harness.

Switch games = turn power off, flip up top of CP (takes 1 sec because there's no need to keep it locked), swap cab jamma extension harness to game of your choice. Turn power back on.

No interference, no lost signals, in theory no issues at all.

You'll have to handle the kick harnesses (if any) as well. And use decent quality jamma extension harnesses.

So far I'm running this way with Gaunt Leg and NBA Jam and it works well for me. Probably going to add a 3rd board before too long but you could stretch it up to 10 if you wanted.

As long as you keep using good harnesses, this should always work great, but it's a little more work to switch games. For myself, I'm looking to get a JAMMA cab where I can switch boards easily - I don't like 60-in-1 or switching systems or N-in-1 MVS carts. But that's just me.
 
As long as you keep using good harnesses, this should always work great, but it's a little more work to switch games. For myself, I'm looking to get a JAMMA cab where I can switch boards easily - I don't like 60-in-1 or switching systems or N-in-1 MVS carts. But that's just me.

That's pretty much my mentality about it. I'm making a multi-mostly-konami cab. So far, the list of games to be inside will be TMNT, TMNT TIT, Sunset Riders, Simpsons, Bucky O'Hare, Cowboys of Moo Mesa, Captain America and the Avengers, Spiderman, Crime Fighters, and G. I. Joe. I may do mystic warriors or some of the other data east 4-player games, but for now, I'm trying to keep it mainly konami. Also, the rotary switch design was my initial desire, but I would definitely have to have one custom made for this, as I'm not big into digital buttons and electronic relays. Maybe I should just try connecting up the controls to see if they would work alright... I still need to build a rack for all these boards anyways.
 
As long as you keep using good harnesses, this should always work great, but it's a little more work to switch games. For myself, I'm looking to get a JAMMA cab where I can switch boards easily - I don't like 60-in-1 or switching systems or N-in-1 MVS carts. But that's just me.

Yeah. Realistically it takes me about 45 sec to switch games with half of that time adjusting the monitor settings to tweak for each game. (I've run the monitor remote controls in under the pop up CP as well).

Ignoring the monitor adjustments it takes about 15 seconds to switch between boards.

I'm using the Bob Roberts extension jamma harnesses and they seem to work well; the jammaboards ones were absolute shit.
 
All the issues mhkohne mentioned can be avoided by going with a strictly mechanical switch.

But as noted no such beast exists, so you'd have to make your own.

I actually looked into this years ago and designed one that I have yet to get back to building, thanks to some personal issues.

It'll be a twelve game switcher. Power would be cut when the knob is pushed in, which you'll have to do before you can turn the knob to one of twelve positions where you release it, allowing it to spring back out restoring power. It'll be done this way so that the breaking and making of all connections will occur when there is no power applied. (So there is no arcing or scoring of the phosphor-Bronze connections to worry about).

And turning the knob to switch between games has a dual purposes in that wiping occurs of the contacts between the twelve positions.

Twelve small extension harnesses would be needed. I just have to decide between "store-bought" JAMMA finger boards or finger boards I'll have to make myself, since they will be a permanent part of the switcher.

I know that the fingerboards Bob Roberts sells don't have a high cycle life because they weren't made for a lot of connecting and disconnecting, so friction would too easily damage the traces over time. However I do have some fingerboards that I picked up via eBay years ago that are more durable.

The plans for this switcher are all but done.

(I guess that an easier, but dirtier way to switch between games would be to use multiples of those rotary switches referred to above, while making sure there is no power applied when changing between positions).

Darren Harris
Staten Island, New York.
 
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All the issue mhkohne mentioned can be avoided by going with a strictly mechanical switch.

But as noted no such beast exists, so you'd have to make your own.

I actually looked into this years ago and designed one that I have yet to get back to building, thanks to some personal issues.

It'll be a twelve game switcher. Power would be cut when the knob is pushed in, which you'll have to do before you can turn the knob to one of twelve positions where you release it, allowing it to spring back out restoring power. It'll be done this way so that the breaking and making of all connections will occur when there is no power applied. (So there is no arcing or scoring of the phosphor-Bronze connections to worry about).

And turning the knob to switch between games has a dual purposes in that wiping occurs of the contacts between the twelve positions.

Twelve small extension harnesses would be needed. I just have to decide between "store-bought" JAMMA finger boards or finger boards I'll have to make myself, since they will be a permanent part of the switcher.

I know that the fingerboards Bob Roberts sells don't have a high cycle life because they weren't made for a lot of connecting and disconnecting, so friction would too easily damage the traces over time. However I do have some fingerboards that I picked up via eBay years ago that are more durable.

The plans for this switcher are all but done.

(I guess that an easier, but dirtier way to switch between games would be to use multiples of those rotary switches referred to above, while making sure there is no power applied when changing between positions).

Darren Harris
Staten Island, New York.

Nice switch idea. The push of the switch would be a momentary OFF for all the power at once - REALLY good plan, because now you don't have to worry about the switch being a non-shorting type. Sometimes there's nothing like a good mechanical solution to a problem!

Another way to approach it would be to make the power switch somehow physically interfere with the rotary knob when it's on. That way you'd have to turn off the power, rotate the knob, then turn the power back on, again blocking the switch. You might even be able to accomplish the trick with a relay that locked the knob somehow.
 
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