On Feb 7, 11:16 pm, "Michael J. Mahon" <mjma...@aol.com> wrote: > > I mean, just pull out the CPU from it's socket. > > No problem--it's silkscreened: 820-0001-04. Yep. Thanks. That's what I was looking for. My rev 1 read xxx-0001-01. Therefore rev 1...4 MLBs can be identified by pulling out the CPU and reading the last two digits. Regards, Jorge.