use strict;
use warnings;

use Algorithm::Loops qw( Filter );

my $blank = '.'; # or "\xFA";

open(my $fh, '<', @ARGV ? $ARGV[0] : '-')
   or die("Unable to open input file: $!\n");
binmode($fh);

local $/ = \16;

while (my $block = <$fh>) {
   my ($hex) = map { substr($_.(' 'x51), 0, 51) }
               join ' ',
               map /.{1,12}/sg,
               join ' ',
               map { sprintf '%02X', $_ }
               map ord,
               map /./sg,
               $block;

   my ($chr) = Filter { s/[^[:print:]]|\s/$blank/sg }
               $block;

   print("$hex   $chr\n");
}