Hi there, I've written an high performance CRC32 lib (at least I couldn't find a faster one). At the moment it's GPL. In case someone want's it to be added to Nut/OS I might be able to be persuaded to release it under BSD. http://www.avrfreaks.net/index.php?module=Freaks%20Files&func=viewFile&id=2954&showinfo=1 Cheers Morty