Posted by u_rebelscum on February 21, 2002 at 02:17:53:
In Reply to: trackball "lag" posted by btoddkelley on February 13, 2002 at 19:00:20:
: I had a friend of mine over who has a real centipede machine and he noticed that the trackball did not respond to movement as quickly as his authentic did. Once it was spinning he felt like the shooter moved at the same speed but there was a lag on "take off". I am using an optipac with an older wico trackball. The pickups are the non active style. I have a couple of questions for the spinner guru's on this:
: 1) what is the limitation as far as optical input? is it in the interface or in the mouse port(serial)? Is there a faster way? (usb pehaps)
USB is supposed to be "noticeably" faster than serial mice. I haven't noticed it though.
: 2) what causes backspin when mame is set too sensitively? is it the software or the hardware? (again is ther a better way to interface?) I have noticed that i cannot get my spinner to backspin in windows no matter how hard i spin it but in mame if i turn up the sensitivity it will back spin. I would think that would indicate software but i am not sure.
Backspin could be caused by either. However, in your situation, it has to be software. My guess is integer overrun: with mame's sensitivty, the mouse "delta" (amount of movement) value is greater than the games maxium delta. Example: mame gets a delta of 128, when the game only has 8 bits (range -128 to 127). With binary, the game would read 128 as -127, thus the backspin.
: 3) has anyone had any luck using 2 trackballs in mame 32? the optipac has 2 serial outputs but my understanding is that windows only supports 1. is ther another way to interface trackball 2? (usb again?)
I have a patched mame32 version, "mame32:Analog+", that can handle multiple USB trackballs/mice in Win98 and WinME, but not WinXP, Win2000, WinNT. Still WIP, so it is not as "feature rich" as the mame:Analog+ version. More info at my site below.
: Thanks in advance for the help.
: Todd