On Tue, 24 Mar 2009, J.C. Roberts wrote:
Any chance you know the brand name of the upgraded processor?
It's a FastMac. 1.2 GHz G4. I _think_ the model # is APP-5582. FastMac seems to have removed most of the information for this upgrade from their website.
As for the missing serial (thanks Nick), I tracked down one vendor who made the add-on connector used to enable the on-board serial. It was generally called a "gPort" (also "g3Port" and "g4Port") and was made by a company called Griffin Technologies. From my reading, it seems there were a few different versions of the add-on connector for the various Apple systems. I *think* some of them replace the internal modem (RJ11).
Interesting, thanks for the info. Did you also happen to find out where to actually get one of these?

