On Mon, 27 Dec 2004, Bob Ammerman wrote: > Scott, > > Your test loop is comparing the lo byte of the CRC twice and ignoring the hi > byte! Oops, you're right. It's fixed now. Fortunately I had already tested the algorithm in C. Incidently, the brute force test of all 2^24 combinations (2^16 for the 16 bit CRC and 2^8 for the input byte) takes about 2.37 billion instruction cycles and a minute and 40 seconds to simulate with gpsim. (But my system is an Athlon 64 3500+ ) Scott -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist