Capturing input content with non-printable chars

Capturing input content with non-printable chars

Here is code a snippet : http://jsfiddle.net/ZLr9N/298/

  1. $('#text1').keyup(function(event) { 
    $
    ('#text2').val($('#text2').val()+event.keyCode);
    });

the problem is when user press backspace the second input must reflect the content of the first.