Borrowing the excellent idea Maciep had introducing into mine I would have had 140 .. Not that this would have changed the board but hey. I like the look of this

 Code:
function a($)
    dim $b, $c, $d
    $b = 0^$
    while $
        $c = (($b-($^) & 1)+1) * right($,1)
        $d = $d + $c-9*($c>9)
        $a = ($d mod 10 =) * ($>2&$<7&$b+($<4)=16) * $
        $ = left($,~)
endfunction


Funny how some things don't come to your mind when you stare at your own code for a week.
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