$i = 0;
$TileData = 0x0000;

while(!(eof(IN)))
{
    $BytesRead = read(IN, $TileData, 2);
    unless($BytesRead != 2)
    {
       $NewTileData = (($TileData & pack('S*', 0xFC7F)) | (pack('S*', $GFXFileBits)));
       print OUT $NewTileData;
       $i++;
       next;
    }
}