Hi all, I've coded routines but need to verify that they do indeed produce the correct CRC. To do this, I need 2 known CRC check values. These are obtained by running thru the "standard" check string "123456789" of your algorithm and obtaining the result. I think that the check with CRC-16 on "123456789" is BB3Dh (can someone verify this?) Can someone (with known good code) please tell me what the 2 check CRC's are for both CRC-CCITT (x^16+x^12+x^5+1, or POLY=1021h) and CRC-16 (x^16+x^15+x^2+1, or POLY=8005h) or alternatively, send me known good code in C or VB6? Thanks in advance, Bernard Wood New Zealand -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.