At 12:50 PM 5/21/97 EDT, you wrote:
<SNIP!>
>transmit.  the protocol handled up to 100 sites, though the largest
>installation I know of is 15 or 20 sites.  Part of the setup of the
>system is to put in the highest site number.  The boxes then reset their
>site counters after that number is reached so they don't allocate time to
>nonexistant sites.

Harold,

That was a pretty ingenious token system.  Not bad!

The left-shift you were doing is starting to approach CRC, but in a
simplistic manner.  I use this myself to be better than a checksum w/o the
complexity of a CRC, and it only takes three opcodes:

        (assuming W holds next char to process)
        bcf     C               ; Only needed if you aren't sure...
        rlf     FancySum,F
        addwf   FancySum,F

Andy

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Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865 USA
              Electronics for Industry & R/C Hobbyists
         "Go fast, turn right, and keep the wet side down!"
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