> Also the ending of comparison means a reading of cmcon register.

What do you mean here?  I'm thinking this is along the same lines as the
code example line:

MOVF    CMCON,F         ; with some comment about ending change condition
                        ; or soemthing.

What exactly does reading / writing the CMCON register do?  At one point I
thought that it would "freeze" the values in C1OUT/C2OUT until it was
reset - later I thought that it would clear the interrupt flag bit, and
now I'm back to square one:  I have no idea what it does, but I sprinkle
them throughout my code for "good luck".

> high impedance metter I suppose,

I will plead ignorance, here.  I hear/read references to "high impedance
meters", and I never know what to think.  Why wouldn't every meter be high
impedance?  My meter is a pretty cheap one, I guess, so it's probably not
high impedance.  For my tests, though, it was good enough.  (The
comparator inputs were so far apart (> 1v) that I doubt the meter would
cause problems)


So the update is that I was able to figure out my problem.  The 16f628
errata (As someone mentioned) notes that in mode 1, the RA3 input doesn't
get fully connected to the comparator input (whatever that means), so it's
broken.  I did find a work-around (involving the internal vref module, and
toggling between two comparator modes), but it caused me quite a headache
in the mean time.

Thnks for your input.

-Steve

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