I was wondering if the GP-Wiz49 was compatible with other encoders.
It SHOULD work fine.
They are separate devices.
Unless there is an unexpected conflict of some sort, it shouldn't be any different than having a gamepad hooked up with the mini-pac--which is known to work.
I bought and intended to use a couple mini-pacs but now I don't know if they'll serve a purpose.
They will let you hook up your trackball and spinner, as you mentioned in your original post.
Alternately, you could sell them and use a single mouse hack from Oscar, and wire it up using the switching circuit diagrammed on his website.
I'm guessing the Wiz49 needs the buttons and sticks to run through it so it can change the digital restrictor modes and use the stick.
Yes, unless you hook up a "programming device" like we were discussing earlier in this thread.
I figure I can use the minipac for the spinner and trackball, but can I also hook other buttons that I don't intend to use to swap modes up to them (if I actually needed more)? I just wasn't sure how this affected other encoders.
They should all be seen as separate devices, so SHOULD work together.
You should also be able to hook up any extra buttons to the Mini-pac, if necessary.
Also, stemming from this I wasn't sure if I needed one or two encoders. Again this would depend on whether certain buttons can run through the mini-pac or not.
You need one GP-Wiz49 for each 49-way you plan to use.
I can't tell if you are planning for one or two sticks, but each needs its own interface.
Does the 49 way require any power, like the P360s, or is it fine on its own?
It gets its power through the interface.
The reason that the P360 needs external power is that there is not interface board for it.
It hooks directly to the encoder.
And would I need to change the version of MAME I'm running in order to read the analog directions?
I THINK that 49-way support is built into command line MAME, but will be corrected by someone shortly if it isn't.