4 player panel encoder questions

[Rok]

I am currently working on a standalone plug n play (to a tv) 4 player panel. As of now, my layout calls for the following inputs

4 sticks
20 buttons (6 for p1 p2 and 4 for p3 p4
1 through 4 player buttons
4 coin buttons
pause/exit

which equals 46 inputs if my math is correct. THe keywiz st 40 only has 40 inputs, and the only encoder I can find that supports more than this is the ipac4 which costs nearly twice as much as the keywiz. In order to stay within my budget, is the following possible?

Can I get away with 2 coin buttons? Is there any reason each player needs their own? Then, could I give p3 and p4 only 2 buttons? Most of the 4 player games that would be played on this cp would be beat em ups like Simpsons and X men. I know that in X Men you need 3 buttons for a mutant power, so would it be possible to substitute a third button for simultaneously pressing both button 1 and 2?

I always see people using 4 buttons for p3 and p4 but as of yet haven't come across any games that use more than 3. (This is a strictly mame cabinet, no other emulators)

[Dazz]

Build the controller how you want it to ultimately be the first time.  Don't short yourself and just get whatever.  If you want player 3 & 4 to have 4 buttons each, then spend the extra to get the Ipac4 and do it right the first time.  This way down the road later you won't be wishing you had only added those other buttons like you originally wanted. 

[severdhed]

now, i could be wrong, but the keywiz has 40 inputs, but 32 shifted inputs using the shazaam button.  from what i read, you can use some special adapters that they sell, to make a button perform a shifted function without pressing the shazaam button. 

http://groovygamegear.com/webstore/index.php?main_page=product_info&cPath=76_80&products_id=203



so  you could connect your 4 joysticks (16 inputs) and 20 main action buttons (20 inputs) and your four start buttons (4 inputs) to the main inputs on the keywiz. (20+16+4=40)  then using 6 of those adapters, you could set up your 4 coin buttons, pause and exit  on the secondary inputs. 

at least that is how i undertand it to function after reading the documentation on their website...hopefully Randy or someone who has one of these things can confirm that.  I just happened to be planning a 4 player panel as well, and i think this is the route i plan to take.  although it may be  alittle while before i order everything so that won't be much help to you.

as for 4 player games with 4 buttons, there are a few, according to MAWS

http://maws.mameworld.info/maws/

choose deluxe search,
set simultaneous players to 4
set buttons to 4.

[Endaar]

You're talking about a ~$30 difference, and while I'm not trying to spend your money for you, I can say that you will make your build much more difficult trying to find a way to avoid buying the IPAC4.

If you are really determined to save that money, I'd suggest using the shift function for the eight start and coin buttons. That said, if you cut corners you WILL end up redoing this down the road.

Endaar

[drventure]

Spend a few extra bucks and get the Ipac4. Definitely worth it, esp for a 4 player cab.

[bkenobi]

The GP-Wiz40 has 40 inputs.  8 of those inputs are set up as 2 digital joysticks and the rest are for button inputs.  However, there's nothing keeping you from using 4 or 8 of those inputs for 1 or 2 more joysticks.  Also, this interface has a feature that allows you to use it for rotary joysticks (think Ikari Warriors) if you want.  I've been using the 32-input version of this encoder for years without any complaint.

From what I read, the KeyWiz40-ST has 40 inputs and, in addition, 32 of those can be used with the Shazaam! button to add more capability.  I wouldn't call that 72 buttons, though.  Anyway, I don't read that 8 of the buttons are not usable.  I think those are just the 8 inputs used for the 2 preconfigured joysticks.

[deepblue]

+1 for the IPAC4

That said, My 4 player panel only has one coin button, which I have configured in Mame to credit P1,2,3 and 4 simultaneously.

Personal preference in the end, but using a coin button isn't exactly authentic anyway right?

If you want to keep the aesthetics of 4 buttons you could just wire all 4 into one keywiz/ipac input and config Mame accordingly.

For what it's worth I also have a working coin door that will wire to P1 and P2 respectively, but just for fun.