Disc reader project -- quick status update

Eric Smith wrote: Eric, Thanks for the discussion. I guess I've had some misconceptions and am trying to work them out. When I think of sampling, I think of regularly recording the value of a pin every so many units of time. So it's possible to miss pulses/edges/etc if they happen to fall in between the samples. Then I'm thinking of polling a pin where you do this sort of thing: waitforlow: if pin != low then waitforlow And then edge detection comes to mind, where polling or sampling could potentially miss a very small pulse(perhaps a couple clocks wide) --- edge detection would detect it. My mind also goes to bit-banged UARTs for serial ports. Isn't there a difference in implementation to a sampled-approach? Or is the difference just that bit-banged ones sample once, and the other usually samples multiple times? I guess I see "sampling" as a repetitive based-on-clock behavior and differentiate that from a one-time-read of a pin where the next read isn't well-defined. Ie, the code path to the next read isn't necessarily the same each time. Does any of my ramblings make sense? Is it all just semantics? Thanks Keith