Thanks AWOL--I just changed my title to make the analog read speed I'm looking for clearer. Off-piste has to do with changing the way the core clock frequency is divided, right? Can I get the three orders of magnitude increase I'm looking for by doing this? I don't need huge resolution on my reading (I think 8-bits would be plenty). I'm going to look up "comparators", "zero-crossing detectors" and external clocks now.