So flip the bits? Thats xor/xor 

10001010
10001101
     +-+

[download]

So you write 

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 }

[download]
To turn $f into $g, you take the the xor of $f and $g to create $r, and then xor $f with $r to get $g

In reply to Re: Modifying multiple bits in a byte - bitwise operators (xor) by Anonymous Monk
in thread Modifying multiple bits in a byte - bitwise operators by stevieb

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