How do I alter trackball / spinner speeds?

[LeedsFan]

I'm using Mame v.87b with Ultimarc trackball and Oscar Model 3 spinner connected to Optipac in USB mode.  How do I alter trackball and spinner sensitivities on a game by game basis?  I take it I can put some commands in the .ini file on a game by game basis.... but I don't know what settings to alter.

Some games seem better than others. Arkanoid seems very difficult to play, as does Marble Madness. I'm spinning like mad to get any sort of speed/movement.  Centipede seems quite playable though as it stands.

In a search I did come across a great thread that tried to document some of the classic games with "turrns to movement" ratios. Sort of "180 degree turn of wheel = 90 degree movement in Championship Sprint".   But nothing was  mentioned about what you actually change in Mame to achieve these adjustments.

[Minwah]

Run the game,
Hit Tab,
Select 'Analog Controls',
Alter the Dial or Track sensitivity

[SirPoonga]

also adjust your mouse sensativity in windows.  This helps for outside of mame