How about making a small program that simply changes the OSCCAL value when you depress a button. Each button press could decrease the value by 1 (or whatever) and measure the CLKOUT until you get 3.686 or whatever you want. Then by knowing how many button presses it took, define that value for the OSCCAL and reload it. --Andrew _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body