hrtbreak wrote:

What kind of CPU and O/S are the rovers using (or do I really want to know)?

The chip itself is a RAD6000, a hardened variant of the
Power-PC architectu
http://mars.tv/mer/spacecraft.html

VME bus based processor card built by BAE, O/S is VxWorks:
http://www.washingtontechnology.com/...e/21333-1.html

And now that I've googled around a little, there's even a
HowStuffWorks page with a surprising amount of information:
http://howstuffworks.lycoszone.com/mars-rover4.htm