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Main => Main Forum => Topic started by: reko19 on August 01, 2008, 04:19:55 pm

Title: help with trackball speed adjustments
Post by: reko19 on August 01, 2008, 04:19:55 pm
I was messing around last night with trackball and spinner settings. Seem to be having problem with Millipede and Centipede. No matter what values I have for trackball digital speed and sensitivity I don't see any changes in performance on the X coordinates. Other games seem to be responding just fine. Although for the spinner in the Arkanoid I had to crank it all the way up. Any ideas?

Also, could someone explain the difference between digital speed and sensitivity? Depending on the game I end up adjusting one or another to get t he desired results. Thank you.
Title: Re: help with trackball speed adjustments
Post by: DeLuSioNal29 on August 02, 2008, 12:34:32 am
I usually just mess with the analog percentage.  I never touch the digital speed.

I'd also like to know the difference between the two.  I asked it once here, but got ignored.   :dunno

Anyone care to explain the difference?

Thanks in advance!

~ DeLuSioNaL
Title: Re: help with trackball speed adjustments
Post by: Loafmeister on August 02, 2008, 12:49:03 am
Oye, I'm probably wrong here, but I always though the "digital speed" was when you were setting the game to use digital joysticks as the controller.
Title: Re: help with trackball speed adjustments
Post by: u_rebelscum on August 04, 2008, 05:48:07 pm
Digital speed is for using digital devices for an analog port.  It's count per frame, IIRC.  Example: if you push the left arrow in tempest, & the digital speed is set to 8, then mame tells the game that the "dial" spun 8 counts every 1/60 of a second if the sensitivity is set to 100%.

Sensitivity effects both analog and digital devices in analog inputs.  If set at 50%, it sends the game half the number as if set to 100%.  So to expand the above example, if the sensitivity is set to 75% all else the same, mame would send the game a delta of 6 per frame (8 * 0.75 = 6).

Digital speed shouldn't affect analog devices' inputs, but there are cases where it is reported to do so, most that I can't reproduce any more.  The one that I can reproduce is a case of incorrect remapping of analog devices to the "...inc"/"...dec" ports instead of only to the "...analog" port; resulting in mame seeing the analog device as digital, and using the digital speed to fake analog.


The reason many need a high sensitivity for arkanoid is the original spinner was geared that resulted in a high count per revolution (486 (http://wiki.arcadecontrols.com/wiki/Spinner_Turn_Count)), higher than older spinners (usually between 96-192 cpr, or 24 to 48 teeth disks).  The TT2, TT-HL, & SpinTrak spinners have high enough resolution (1200 cpr) that they need sensitivity closer to 40% (486/1200) than 250% (486/192) that older spinners need.

Centipede has been giving problems for a while.  The game only has four bits per axis, so it can only get a max of +- 7 counts per frame.  (Most other games can do +- 127 cpf.)  So either the game polled the TB more often than mame does, or some other hardware count or something else is going on that isn't emulated yet.

edit: spelling