It uses a PS/2 connector, but actually communicates through an SGI proprietary protocol. Unfortunately it looks identical to the real deal PS/2 Granite dampened Alps board and I didn't check the numbers. Was not advertised as tested or working, so it's not like the seller actually tried it and misrepresented it... The ad did say PS/2 but that is the only inaccuracy, and it is in fact a PS/2 connector. I also got it like a month ago and have been too busy to get a cable (I didn't have a single detachable PS/2 cable in my junk box) until I picked one up at the Goodwill the other day.
If someone wanted to take an old AT101 and do a vulcan keyboard meld to get the "good" switches, this might work. In fact I wonder if the matrix is the same; the case looks very similar. Unfortunately the only other Alps board I have laying around is an AT101W that's well loved.
