> CRC routine? Ah well, here you have one (dunno about the speed). You > probably want to put the _CRCByte routine into the loop of _CRCBlock... Nice routine! Speed will be at most 8 * inner loop. A quick off the top= =20 of my head count (at one point I actually had them all memorized, by=20 accident) gives about 65, so maybe 570 for the whole routine.