It's unknown to me - I found it at a thrift store. I have a PS/2 to USB ordered - I can only presume that it works, based on its condition and build quality. I opened up the back, and the trackball has its separate mechanism, connected via a plug or two. Having read so much about ALPS switches, I've now scratched that itch. I think the keys are a bit on the sticky side - and it's not due to its age or condition - it's very clean - I think it's a characteristic of the keys/switch. Maybe lube would help. And I don't want to write it off until I've used it for a few days - it takes me a while to get the feel of some keyboards. I still want to try buckling switches to see what the fuss is about.
