Voici donc une fonction PHP qui permet de convertir les fichiers codés en ANSI vers de l'ASCII :

 function ansitoascii($string) {
    $asciiarray[] = 142; $ansiarray[] = 196;
    $asciiarray[] = 143; $ansiarray[] = 197;
    $asciiarray[] = 146; $ansiarray[] = 198;
    $asciiarray[] = 128; $ansiarray[] = 199;
    $asciiarray[] = 144; $ansiarray[] = 201;
    $asciiarray[] = 165; $ansiarray[] = 209;
    $asciiarray[] = 153; $ansiarray[] = 214;
    $asciiarray[] = 154; $ansiarray[] = 220;
    $asciiarray[] = 133; $ansiarray[] = 224;
    $asciiarray[] = 160; $ansiarray[] = 225;
    $asciiarray[] = 131; $ansiarray[] = 226;
    $asciiarray[] = 132; $ansiarray[] = 228;
    $asciiarray[] = 134; $ansiarray[] = 229;
    $asciiarray[] = 145; $ansiarray[] = 230;
    $asciiarray[] = 135; $ansiarray[] = 231;
    $asciiarray[] = 138; $ansiarray[] = 232;
    $asciiarray[] = 130; $ansiarray[] = 233;
    $asciiarray[] = 136; $ansiarray[] = 234;
    $asciiarray[] = 137; $ansiarray[] = 235;
    $asciiarray[] = 141; $ansiarray[] = 236;
    $asciiarray[] = 161; $ansiarray[] = 237;
    $asciiarray[] = 140; $ansiarray[] = 238;
    $asciiarray[] = 139; $ansiarray[] = 239;
    $asciiarray[] = 164; $ansiarray[] = 241;
    $asciiarray[] = 149; $ansiarray[] = 242;
    $asciiarray[] = 162; $ansiarray[] = 243;
    $asciiarray[] = 147; $ansiarray[] = 244;
    $asciiarray[] = 148; $ansiarray[] = 246;
    $asciiarray[] = 151; $ansiarray[] = 249;
    $asciiarray[] = 163; $ansiarray[] = 250;
    $asciiarray[] = 150; $ansiarray[] = 251;
    $asciiarray[] = 129; $ansiarray[] = 252;
    $asciiarray[] = 225; $ansiarray[] = 223;
   
    $i = 0;
    while ($i < sizeof ($asciiarray)){
        $string = str_replace(chr($asciiarray[$i]), chr($ansiarray[$i]), $string);
        $i++;
    }
    return ($string);

}