my ( $n1, $n2 ) = ( ord( substr( $v1, $i, 1 ) ),
ord( substr( $v2, $i, 1 ) ) );
$n1 += 256 if $n1 < 65; # letters sort earlier than non-letters
my ( $n1, $n2 ) = ( ord( substr( $v1, $i, 1 ) ),
ord( substr( $v2, $i, 1 ) ) );
$n1 += 256 if $n1 < 65; # letters sort earlier than non-letters