IPac: Wire tripple action key?

[Akuma]

Hello everyone. I just got a short question - maybe I just can't think at the moment, but I somehow don't seem to get it.

I would like to ask if it is possible to wire pushbuttons in a way, that you have some sort of wired hotkey e.g. You have buttons 1 to 3 and an extra button which acts as pressing button 1, 2 and 3 alltogether.

You might say - "just wire it and make it a hotkey in mame". Sure, that's what I have done but actually I am looking to save one or two button connections on my ipac for another button.

What I tried so far didn't work and as I said, I just can't think at the moment. When I tested it, pressing each of the buttons, 1, 2, 3 OR 4 was all the same: button 1,2 and 3 being pressed.

Anyone got a diagram how to wire?

[NoOne=NBA=]

You need to put diodes between the buttons and input terminals, to keep the wires from being physically connected to each other.
The diodes will keep the other buttons from grounding out when you press only button 1, etc....

[Akuma]

Okayyyy : )

Since I have a very very limited knowledge concerning wiring I have to ask where to put the diode: At the ground side or the positive side? Will any diode do?

[Spaz Monkey]

Just thinking off the top of my head here....  From the jamma harness you will want to split the wire for P1B1 (Player 1, Button 1).  One half goes to p1p1 NC (normal close), the other goes to hot button switch NC.  Repeat for p1b2 & p1b3.  Hot button then should have 3wires connected to the NC.  All should share a common ground.

Why not use the Shift function on the ipac?

[SavannahLion]

Okayyyy : )

Since I have a very very limited knowledge concerning wiring I have to ask where to put the diode: At the ground side or the positive side? Will any diode do?

If I understand what you're trying to do....

You want it on the hot, or positive, side of the switch combining both. You need one diode for each line coming onto the switch. In the schematic below, I wired it up for three buttons. SW1 and SW2 are standard function buttons, SW3 is wired to trigger both SW1 & 2 at the same time. The diode (D1 & D2) prevents the buttons from triggering each other.

You can expand the schematic to include as many buttons as you want triggered at the same time.

As for diode, for general purpose, I try to use any 1N400* diode such as 1N4001, 1N4002, etc. These are simply signal lines so almost any diode will do. Try to avoid oddball stuff though, like Zener's or the like. The band goes with the "flow" of the electricity. Rather than explain, I suggest you read about it from someone much more qualified than I.

edit: I don't have anything better online for diode tutorials. Can anyone one up me with one?

Also forgot the pic

[NoOne=NBA=]

Sorry I didn't have time to post diagrams, etc... earlier.
I still don't have time, but Savannah's drawings are what you need.
The only difference is that you will have a 3rd line with a diode off the 4th button.

[Akuma]

Hey, I really get the hang of it! thank you for your answers!