# service routines are expected to preserve it and for own well-being
# zero it upon entry.
-while (($output=shift) && ($output!~/\w[\w\-]*\.\w+$/)) {}
-open STDOUT,">$output";
+$output = pop and open STDOUT,">$output";
($CTXA,$INP,$NUM) = ("A4","B4","A6"); # arguments
$K256="A3";