10001010
10001101
     +-+

##</code><code>##

use Data::Dump;
$f = 'Q';
$g = "\261";
$r = $f ^ $g;
$t = $f ^ $r;
dd({$_, unpack('b*', $_)}) foreach ($f, $g, $r, $t);
__END__
{ Q => 10001010 }
{ "\xB1" => 10001101 }
{ "\xE0" => "00000111" }
{ "\xB1" => 10001101 }