Build Your Own Arcade Controls Forum

Main => Software Forum => Topic started by: LeedsFan on June 28, 2008, 06:15:51 am

Title: Replicating spinner / trackbal performance in Mame?
Post by: LeedsFan on June 28, 2008, 06:15:51 am
I've done a search for this but couldn't find anything. Basically I'm wondering if there's some kind of info anywhere for individual spinner/trackball games in order to have them perform as close as possible to the original arcade cabinet.

What I mean is.... an original Arkanoid cabinet would take  X  turns of the spinner to move the bat one sweep across the screen. And for Tempest  X  turns of the knob to make one full revolution on a certain level.  See what I'm getting at?

You couldn't have a list of .ini settings for each game because everyone is using various different spinners/trackballs with differing resolutions. But armed with the info from the original cabinets people could tweak their own Mame setting to get the game runing as close as possible to the original.

Of course this could be a huge undertaking if none of this info is logged already by someone. Just posting here in some kind of hope.  :blah:
Title: Re: Replicating spinner / trackbal performance in Mame?
Post by: vizzinni on June 28, 2008, 07:31:42 am
Here's a start...

http://forum.arcadecontrols.com/index.php?topic=23967.msg201068#msg201068 (http://forum.arcadecontrols.com/index.php?topic=23967.msg201068#msg201068)

Title: Re: Replicating spinner / trackbal performance in Mame?
Post by: LeedsFan on June 30, 2008, 03:47:07 pm
Some very good info in that thread, even though it's 4 years old.   :P

I'd be very interested to find out how people have their setting in Mame for Marble Madness. I'm using a Happs 3" High-Lip trackball and I noticed that I just couldn't get the marble to move how I liked. The analog settings in Mame are preset for this game at 30%. I set it to 100% (as I assumed the arcade machine also used a 3" trackball of similar resolution) and the game plays much better now. I can actually get to the aeriel screen now whereas before that was just impossible.

Conversely I don't want the games to be playing too easy. Not sure if I was supposed to get that far on just my second go.  :p
Title: Re: Replicating spinner / trackbal performance in Mame?
Post by: u_rebelscum on June 30, 2008, 07:29:45 pm
I'd be very interested to find out how people have their setting in Mame for Marble Madness. I'm using a Happs 3" High-Lip trackball and I noticed that I just couldn't get the marble to move how I liked. The analog settings in Mame are preset for this game at 30%. I set it to 100% (as I assumed the arcade machine also used a 3" trackball of similar resolution) and the game plays much better now. I can actually get to the aeriel screen now whereas before that was just impossible.

Marble Madness is an interesting case.  It used atari's 3" TB (& happs uses the atari TB design), but rotated 45 degrees.  When Mame converts the PC's mouse x,y data to the game's rotated grid, it scales it by ~140% (to be more precise, the square root of 2).  So for a closer scale, you'd want ~70-71% sensitivity (one over the sqrt of 2) assuming MM hardware also reads the quadrature signals at 4x like PC mice (vs old 2x or 1x) and you're using the original encoder wheel that came with the TB, and happs rollers have exactly the same diameter as atari's (they basically do, but are made of different material).

Another point is as part of the convertion, mame can only send half of the rotated grid coordinates.  Examples: Mame can send the game 0,2 or 1,1, but not 0,1 nor 1,2 (quick rule: if sum of x + y = even, mame can send it to the ROMs, if odd mame can't).  As the convertion is done after the sensitivity is applied, mame's control is half as precise as the original, even if the sensitivity is exactly perfect.  (IMO mame still plays well, if not exactly the same.)

So if you really wanted to make the control as close to the original as possible, you'd need to make a CP with the TB(s) rotated 45 degrees, and edit out the convertion code from mame, and then set sensitivity to 100%.


The above reasons are why it's not easy number matching mame's sensitivity.