Here you go:
http://innovationfirst.com/FIRSTRobotics/system.htm
Quote:
Looking to burn rubber in competition? Take a peek under the “hood” of any FIRST robot, and you’ll find an Innovation First Control System. Whoa- are you seeing this?
Ten microcontrollers. Scores of analog and digital inputs. Twenty-four motor outputs. And a user programmable processor for enhanced robot control. This bad boy even feeds critical information from the robot back to the pilots. In other words, you can put the pedal to the metal any way you like it. Sweet. This state-of-the-art control system was originally designed for the FIRST competition, but it’s red-lining with educational opportunity. Imagine what it can do for you.
(PS, Now I know what's fueled IFI to update their site...

)
That's one location where they mention it. I think in one of the old guides they have a map of all the Stamps in the system. There's 3 on the RC for processing the program, at least one on the OI. There's at least one in each modem...I think...
I've got to find that diagram, I know I've seen it before. I'll just post back when I find it...
::scavenges through notebooks, web pages and junk::
BTW-I think that the MCs in the radios are PIC's, Right? Maybe the OI already runs on them, and that's one reason why IFI chose them. Just a thought...