I got my hands on a macintosh portable trackball, and from reading the manual it seems to be a regular ADB input device. I'd like to connect it to an ADB converter but I'm wondering what the pinout is. Can someone with a portable please trace it? Trackball uses pins 1 (GND), 27, 28, 29. Looking at the pics of the logic board online, it looks like they go into PMGR chip, which is in line what is stated in the manual that ADB on the portable is handled by a PMGR chip and not a separate one. I'm a bit confused why there are four pins used, since in ADB, fourth pin is used for power switching, which I doubt this trackball has anything to do with.
Thanks on the help.
Thanks on the help.