Looking for more inputs from my IPAC2, will this work?

[Dustin Mustangs]

First off, hello everyone.  I have been lurking on these boards for a while now and have finally gathered enough info to start an arcade project.  I am doing a 2 player Mame cabinet via an IPAC2.  Well I have found that the standard number of inputs on the ipac just isn't going to cut the mustard for what I want to do.  I realize the capability of the shift function should satisfy my needs, but I want this to be real user friendly for a non-mame person and I am not worried about having a crowded cp so I want dedicated buttons for a number of admin commands.  I still plan on using the shift key for the less used functions and for things like escape so they don't get hit by accident.

Well, long story short, I was wondering if you could wire a button up to the shift input and an additional input at the same time.  In theory this would ground the shift input and the normal input with the same button push giving you a shifted request with only one button push and potentially doubling the number of inputs on the IPAC.  I would just give this a try, but I am a little worried about what will happend because I would really be wiring two inputs on the IPAC directly together and my intuition tells me that may not be the best thing to do to my brand new IPAC. 

Any input on this??

 

PS - Thumbs up for a great board!!

[markrvp]

Please list the inputs needed.  There may be enough inputs in an easier way you may not have thought about.

[Dustin Mustangs]

- 7 button pattern for both player 1 + 2
- 1 (or hopefully 2) on each side for visual pinball
- 1 start button for both player 1 + 2
- 1 coin button for both player 1 + 2

This is already an IPAC full of inputs, or two over if I put two buttons on each side for pinball (for bump).

[markrvp]

All of the admin functions can be done with the shift key and no additional buttons, so If you eliminate the admin buttons, then the remaining inputs are exactly 30.

[RayB]

To answer the original question, you can't wire two buttons to one input and then expect two different keys to be detected. That's ridiculous.

What you can do is wire two buttons to the same input and have them both act as the same input. (ie: If you have pinball buttons on the sides, you could have them be wired to the same input as one of your primary buttons.)

1 button going to 1 input = 1 key press. 2 buttons going to 1 input = 1 keypress, etc

[ahofle]

To answer the original question, you can't wire two buttons to one input and then expect two different keys to be detected. That's ridiculous.

I think his original question was whether he could wire ONE button to TWO inputs, one of which would be the shift function ('1' key by default), the other of which would be, say '2' (for an ipac shift function of ESC).  I am personally curious if that would work, although I'm doubting the shifting functionality of the ipac will work that way.  I can't imagine you'd hurt anything by trying though.

[RayB]

Oh I see. Stupid me.

Sorry. Now this sounds like a great idea. I think it might work, though I'd be curious if the "polling" might sometimes detect the normal key JUST BEFORE it detects the shift. On a normal key, a person always hits shift FIRST, ensuring that the encoder knows it's pressed. With this set up it might be a 50/50 chance it works or doesn't...

[ahofle]

Oh I see. Stupid me.

I think it might work, though I'd be curious if the "polling" might sometimes detect the normal key JUST BEFORE it detects the shift. On a normal key, a person always hits shift FIRST, ensuring that the encoder knows it's pressed. With this set up it might be a 50/50 chance it works or doesn't...

Yeah that's what I was thinking too.  The '1' would definitely have to come first.

Dustin Mustangs, give it a shot and let us know!

[Popcorrin]

Actually I'm pretty sure Andy Warne has verified that this will work.

[Dustin Mustangs]

I diode makes perfect sence.

[Grasshopper]

Andy Warne has confirmed it will work and there is a diagram on the Ultimarc website that explains how to do the wiring.

http://www.ultimarc.com/extra_shift.html

[Tiger-Heli]

Actually I'm pretty sure Andy Warne has verified that this will work.

[Dustin Mustangs]

Wow, good stuff!!   

[Tiger-Heli]

Wow, good stuff!!