OT whats a Alpha 2100 server A500MP?

I cannot believe this lucky dog friend of mine. Last month he buys a Compaq 1265 at auction cheap with a cracked display, and compaq replaces it under warranty free. This week I tell him to check out a auction I went to where a big bidder defaulted, and comes back with this "still under hardware support" Alpha 2100 server model A500MP, and the price was too good to even discuss. Now we want to play with it though, and neither of us has a clue where to start. (hint it won't be the $200/hr Compaq software support line) The only thing that came with it is a DAT drive (worth more I bet than he paid for the whole thing). On the back it has a couple PS/2 mouse/keyboard type connectors, a serial port, and I think it has a ethernet card. Software on it might be OSF1. HELP. It is too heavy for "us" to move out of his SUV, so we plan to back it up in my driveway and run an extension cord to it and whatever else we need to for "testing". Just finding out what is inside would be real nice. Thanks.