Papertape convertor

<?
    //
    // Papertape Convertor v1.0 by Edwin Groothuis ([email protected])
    //
    // $Id: papertape.php,v 1.1 2001/09/04 12:01:19 mavetju Exp $
    //
    // If you didn't get this file via http://www.mavetju.org, please
    // check for the availability of newer versions.
    //
    // See LICENSE for distribution issues. If this file isn't in
    // the distribution, please inform me about it.
    //
    // Feel free to use this yourself.
    //

    //
    // Usage:
    //
    // start_papertape()
    // to_papertape(...)
    // finish_papertape()
    // stop_papertape()
    //

    function start_papertape() {
	return "___________";
    }
    function finish_papertape() {
	return "|    o. o |";
    }
    function stop_papertape() {
	return "___________";
    }
    function to_papertape($char) {
	$ret="|";

	$char=ord($char);

	for ($i=7;$i>=0;$i--) {
	    if ($i==2)
		$ret.=".";	// feed hole
	    if (($char & (1<<$i)) !=0)
		$ret.="o";
	    else
		$ret.=" ";
	}
	$ret.="|";
	return $ret;
    }

    if ($text) {
	echo "<pre>  ",start_papertape(),"n";

	$len=strlen($text);

	for ($i=0;$i<$len;$i++) {
	    $d=$text[$i];
	    echo "$d ",to_papertape($d),"n";
	}

	
	echo "  ",finish_papertape(),"n";
	echo "  ",stop_papertape(),"</pre>n";
    }
?>

<form method="post" action="<? echo $PHP_SELF; ?>">
<input type="text" name="text" value="<? echo $text; ?>">
</form>