I saw mention of a Measurement Systems trackball in the great finds board, and being who I am I spent the next few hours comparison shopping. After purchasing a completely different device (A RAM Optical Instrumentation control panel), a seller of a significantly cheaper Measurement Systems ball tempted me with a small discount. I was powerless to resist.hellothere wrote: ↑26 Sep 2020, 03:25I guessed at "former military use" and I was right.
4" L x 2.3" H x 4" wide. Trackball is 3.328" diameter. That's pretty big.
The listing quoted the size as 2.5" in diameter and the housing featured buttons. The ball I received was 3" like the other listings.
The ball is massive compared to the Compaq 11800
The build quality of the device is the real appeal. The lower shell is welded aluminum, the top plate is a machined casting, the buttons "plate" is machined, the switches are massive, click, and seem to have lights to illuminate the white buttons. The mechanism is also different from conventional track balls as it uses servos(?) or some other sealed component instead of spoked wheels and optical encoders. A brass plate is installed between the top assembly and the PCB with screws and plastic standoffs. The ball spins on a total of 6 bearings, which are tightly screwed down, but it is possible to clean some debris off them from the other side when the ball is removed. Some lubrication and or new bearings would likely make it even better. The ball is uncomfortably tall when placed on a desk, and the top of the housing features threaded holes and the button assembly and retainer ring have pronounced ridges, so I believe this module was designed to be installed inside of a desk similar to modules installed into some arcade machines. I am not sure what protocol this device uses (only some of the pins on the connector are used, so it might be serial or something completely proprietary. In any case there is more than enough space to hand wire the components to a teensy or internally convert it.
If I successfully convert it or drill some holes in my desk I'll proudly share the results.
Sorry for the false advertising, I'll take some better pictures of the RAM Optical Instrumentation controller tomorrow.