Looks familiar..... When I was at Technicon, I did a course on the PIC. One of the problems in the handbook was a Frequency Meter just like the one you send. We didn't came around doing the problem, but I've got some info on how it works. If any one is interested let me know and I'll see if I can get the info onto the pc. Cheers Herman *********************************************** Herman Theron Hermanus Magnetic Observatory (CSIR) PO Box 32 Hermanus 7200 South Africa Email: hetheron@csir.co.za Tel: +27 283 21196 Fax: +27 283 22039 Cel: 0832973358 ***********************************************