Here is a code to convert ISO 8859-1 to UTF-8 and vice versa without using iconv.
<?php
//Logic from http://twiki.org/cgi-bin/view/Codev/InternationalisationUTF8
$str_iso8859_1 = 'foo in ISO 8859-1';
//ISO 8859-1 to UTF-8
$str_utf8 = preg_replace("/([\x80-\xFF])/e",
"chr(0xC0|ord('\\1')>>6).chr(0x80|ord('\\1')&0x3F)",
$str_iso8859_1);
//UTF-8 to ISO 8859-1
$str_iso8859_1 = preg_replace("/([\xC2\xC3])([\x80-\xBF])/e",
"chr(ord('\\1')<<6&0xC0|ord('\\2')&0x3F)",
$str_utf8);
?>
HTH,
R. Rajesh Jeba Anbiah