> Am I right in thinking that if parity is
> the single bit lsb result of adding all the
> bytes togther, since I am forced to use
> 2 bits anyway I could just keep the lsb
> 2 bits after adding all the bytes together?
> One would still be parity and the other
> would give some small additional protection?
>
> Thanks again!
> -Roman


Actually, the parity is the single bit result of exclusive-oring all the
bits together.

You have to first xor all the bytes together, then compute parity across the
resulting value.

Or you do like the snippet I sent earlier and compute parity across half the
bits in the message for each of your two bits. This will give you a little
better error detection than simple parity because it can detect an even
number of errors if that even number is composed of an odd number of errors
in each half of the message.

Bob Ammerman
RAm Systems
(contract development of high performance, high function, low-level
software)

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