Mame Wiring

[coliveira]

Hello.

I'm hoping you guys can help me out.  I'm trying to help a friend with a 4 player mame cabinet.  He doesn't like the inconvenience of the 4 to 8 way convertible joysticks and would instead like to add a 4 way joystick to his four 8 way joysticks.  I hope this makes sense.  By the way, he's building the control panel himself to attach to a Pit Fighter cabinet.

Anyway, he's already ordered a jpac and an ipac2.  Will it be possible to wire a 4 way joystick to the leftover buttons on the ipac2?  I guess I'm wondering if the ipac knows if there's a button or joystick attached and if it makes a difference. 

Any suggestions on how to help him out if I can't wire it up to the extra button spots?

Thanks in advance.  You guys are incredible.
Chris

[dfmaverick]

How many buttons is he using?

I only ask since he may not have enough inputs with a 4-player cab and an ipac2.(May need an ipac4)

With the 4-way, you can wire it up to open terminals, but you'd have to change input settings in mame for it. It'd probably be better to wire it up in conjunction with the 8-way.(so it uses the same inputs as the 8-way)

The ipac doesn't care if it's a button or joystick, they're just switches to the ipac. Everything is handled in the software.

[coliveira]

Wow.  Thank you for the quick response!

He'd only use 5 buttons per player on the ipac2 (3 buttons for play, 1 coin, and 1 start).  I think that would leave him enough extra buttons for the 4 way joy stick.

To clarify, are you saying to wire the player 1 joystick and the 4 way joystick together so that you could use either one at a given time? 

Also, would he probably just use the player 1 buttons when he used the 4 way or should he put buttons next to it?

This is a bit off topic, what's the most amount of buttons that a 4 way joystick game used?  I'm not sure what he has in store for the control panel, but I'm thinking he might want separate buttons next to it.

Finally, would it make sense to wire the 4 way joystick with the player 1 joystick and any buttons he puts with the 4way joystick with the player 1 buttons and then he could use either as was convenient (and hope his kids and friends didn't screw with him while he was playing).

Thanks again.
Chris

[dfmaverick]

He'd only use 5 buttons per player on the ipac2 (3 buttons for play, 1 coin, and 1 start).  I think that would leave him enough extra buttons for the 4 way joy stick.

4 joysticks = 16 inputs
5 buttons x 4 = 20 inputs

16+20 = 36

I believe Ipac2 handles only 32 (without shifting)

To clarify, are you saying to wire the player 1 joystick and the 4 way joystick together so that you could use either one at a given time? 

Yes.

Also, would he probably just use the player 1 buttons when he used the 4 way or should he put buttons next to it?

Depends on the layout.

This is a bit off topic, what's the most amount of buttons that a 4 way joystick game used?  I'm not sure what he has in store for the control panel, but I'm thinking he might want separate buttons next to it.

Generally two is good. A few may have used more.

Finally, would it make sense to wire the 4 way joystick with the player 1 joystick and any buttons he puts with the 4way joystick with the player 1 buttons and then he could use either as was convenient (and hope his kids and friends didn't screw with him while he was playing).

Yes.

[coliveira]

Fantastic.  Thank you so much.  He actually bought a jpac in addition to the ipac2 and I'm under the impression that they can be connected.  I was going to suggest that he get an ipac4, but he needs the video capabilities of the jpac for booting.

Thanks again.
Chris

[dfmaverick]

There's a sticky thread with pictures of people's control panels at the top of the main forum.

You will see some with buttons next to the 4-way and some do not. I'd suggest taking a look through there to see what others have done for incorporating a separate 4-way.

I missed the comment on the J-Pac. I have not had to use a J-Pac before, so I cannot comment on its function in conjunction with the Ipac. Perhaps others can chime in.

[BobA]

Just put in a switch to toggle the ground between the 1 player 8 way and the 4 way and you will not have any interference problems.

[coliveira]

Thanks again for the help.  I'll have him check out the panels so he can decide what works for him.

BobA, I'm not sure I'm completely following.  I don't know much about wiring.  Are you saying that if I put a switch on the grounds I can switch from 4 way joystick and buttons to 8 way joystick and buttons (the others wouldn't be usable at the same time)?  That'd be pretty sweet if I'm getting that correctly.

Thanks
Chris