My friend just got one of these from a swap meet - I was guessing it was maybe an RT625, but who knows: Sun part number is: 5116425002021 Beneath that it says: 125 03 9726 - 08 REV D underneath the mbus connector is: nc1a971933424c012 nc1a971933424b011 I'm assuming those are serials from each CPU? This is the first time I've seen an mbus module... :) Paul