Details on MER hardware/software

As a software/system engineer, I'm very curious about the software
(and hardware) organization in the MER's control system.
Is there any link to detailed technical information on these
topics?
How is hardware organized?
Which IO does the hardware address?
How is software organized?
How does it communicate with JPL?
The information on the MER's homepage
(http://origin.mars5.jpl.nasa.gov/home/) is fun to start with, but I'd
like to know more on software and hardware details.
Any pointers are appreciated...

Further a related topic that I'm interested in:
How do you navigate in space? Is there a camera that takes images from
stars and tries to match that with an internal computer map? How is
this done?
Again, which hardware and software is used for this?

Ray