For those who want mouse buttons...

[SirPoonga]

For those who want mouse buttons that double as player 1 buttons 1 and 2 here's a pic of a dpdt relay I got form digikey.com.  The part number is in the pic on the relay.  I am only doing 2 mouse buttons.  If oyu want three you will need a triple pole double throw (right?).

Copy and paste the link.
http://free.hostdepartment.com/SirPoonga/images/dpdt.jpg

I haven't gotten around to updating my website yet with that.  But here's the jist of what you see.

For this parts the pin locations on the diagram match up exactly to the pins underneith.  Which is weird, you think the numbers meant something then but they don't in this case.  I originally thought the numbers meant the order of the pins but after testing that was not the case.  It is a what you see is what you get part.

My first step was adding the relay to a wafer bourd (which you can get at radio shack).  I used jumpers then to connect the pins to the correct wires.
Pins 1 and 16 goto a switch on the bottom of my control panel (actually, they ultimately goto the 5v and gnd on a usb port).  when I turn the switch on I get mouse buttons instead of ipac buttons.  My power is coming from the 5v in the usb port, note, this is important as it is a 5v relay to activate the relay.Pins 3 and 4 goto button 1 on the control panel.
Pins 5 and 6 goto the IPAC.
Pins 7 and 8 goto mouse button 1.

Do the same thing for the bottom row of pins for the second control panel button.

Then just mount the relay inside your cp securely.  Works beatuifully.  I didn't want dedicated mouse buttons so this was my solution.

Someone may wonder why I didn't just use a common ground for the ipac and the mouse.  Well, technically ground is ground.  But when two different circuit that are far enough apart but somehow connect to each other share a same ground you get ground loop interference.  Anyone who has setup a home theater system with a subwoofer knows that a ground loop will cause a hum in the sub.  Simular thing here, data might get corrupted or something weird might happen.  So I played it safe and made the relay just switch the grounds from the ipac to the mouse also.

[Brax]

How does it actually work then? You hit a button to switch the relay over? Or does it work automatically somehow? How is it in the proper "mode" when you need it to be?

[Thenasty]

This is the way I did mine.  I use a leaft style buttons, so i just double up the leaft put an electrical tape in between them so it acts as they are separted (no connections to both and no shorting).  But now, I no loger use this method. I don't use the mouse buttons anymore or the MOUSE/TRACKBALL cause I use PURE DOS in my cab.  Of course I use the TRACKBALL for centipede/millipede/marble madness etc... but not the buttons.
Maybe this idea was/never mentioned before, and it miay help someone who uses a leaft style buttons.

[planetjay]

That's a great idea! How did you ever figure that out?  

[SirPoonga]

That's a great idea! How did you ever figure that out?  

Oh yeah, thanks to pj and JustMichael for helping figure it out  

[SirPoonga]

How does it actually work then? You hit a button to switch the relay over? Or does it work automatically somehow? How is it in the proper "mode" when you need it to be?

Read again.

Pins 1 and 16 goto a switch on the bottom of my control panel (actually, they ultimately goto the 5v and gnd on a usb port).  when I turn the switch on I get mouse buttons instead of ipac buttons.

I have a toggle switch on the bottom of my control panel.  The relay is setup so the buttons are mapped to the IPAC.  When I flip the switch on so power goes to the relay (which flips the 4 switches in the relay) I now have those buttons going to the hacked mouse buttons.

[Brax]

Ah, ok so it is a switch to activate the relay. cool.

Man, my cab is going to be full of relays! hehe I already have the power box relay set up. I like this idea to minimize buttons.