I bought an A+ certification book. they talked a lot about cmos in the first chapter (or some more than I would have thought.) CMOS ram that is. anyway here is a link with a java applet :)
a search for "CMOS RAM" gave me this address
talks about clock chips and using the "debug" dos command to clear cmos ram. talks also some about what cmos ram does (saving settings etc.). and some chips I don't understand.. just one of the links turned up by google :)