allanh@netcom.UUCP (Allan N. Hessenflow) (03/07/90)
I've been using a crc routine from a document by Stephen Satchell which is supposed to be the same one used in xmodem. I seem to remember reading about the properties of this crc a long time ago that it would catch all single bit errors and all double bit errors for messages < n bytes long, where n is significantly larger than 6. However, I've recently discovered that this is not the case. Specifically, $41 76 03 01 00 09 has a crc of 37fb, while $41 76 03 01 00 08 has a crc of 37fa. Is this normal for the CCITT CRC, or is the function I'm using faulty? I'm fairly certain it's not a coding/translation error, as I've tried two different functions from the same document with the same results. -- apple!netcom!allanh allanh@netcom.uucp