Ok, I'm not getting it (thats the reason for this 2nd thread).
When you say DX7, does that mean if I have DX8 or DX9 installed on the box I'd have to downgrade to 7.0?
No, the user needs 7.0 or later; 8.0, 8.1, or 9.0 are fine, too. When I talked about analog+ going back to 7, that's for compiling. Sorry for not making that clear.

BTW, (windows) mame has been compiled with dx5 until this version, which is dx7.
Ok...on to the real confusing part: You say Player 1 is controlled by all mice, P2 is USB mouse 1 only, P3 is usb mouse 2......I'm...not.....understanding.
Does that mean Player 1 is essentially not able to be played since its inputs are a mash of all the other inputs (in the case of a Marble Madness 2 player trackball game that player 1's moves will be over-ridden by player 2's movements, but not vice versa....
>> Sorry if I'm being dense here.. <<
Yup, That's what I mean. Weird numbering stuff going on. The number of mice mame finds is one more than the number of USB mice installed (up to mame finding 4 mice), unless zero mice are installed (if that ever happens in windows

).
The first mouse, mame's "mouse one", is the "system mouse", ie all the mice joined. This is just like the mouse cursor in windows; it is controlled by all the different mice you have installed.
The second mouse, mame's "mouse two" is the first USB mouse. This mouse's movements is also going to the "system mouse", aka mouse one.
The third & forth mice are the same way, being the 2nd and 3rd USB mice.
All remaining USB mice (USB mouse 4 and up) mame only sees their inputs in the "system mouse" aka mouse one. This is due to mame's limit of four players = limit of for mice = 1 "system mouse" + 3 USB mice.
For Analog+, it's a little different. It calls the "system mouse" mouse zero, or "sysmouse". This lets all the USB mice drop down a number and seem more normal. Also, Analog+ can see up to 8 USB mice's individual inputs plus the "sysmouse", for a "total" of 9 mice.
Opps, I think I went into too much detail.

I'll end this with:
Analog+ can play marble madness with 2 USB trackballs.