When you have some spare time (spare time, as rare as hen's teeth he says) could we do some ADC stuff?
Sure, I have been planning to write some some basic ADC stuff for the wiki so I will use the 684 as one of the example chips.

But in the mean time you can not beat this foe an explanation. Different chip but most still applies.
http://rentron.com/PIC12C67XAD.htm