Tom, make sure that you've chosen the "High Speed" (HS) option when=20 burning the chip. Jason Mielke Chief Engineer Bliss Communications, Inc. jay@linuxforbroadcasters.com www.linuxforbroadcasters.com > Hello, > I am using a PIC16F877 - 20/P and wish to use a 20.0 MHz resonator wit= h=20 it. > I am using a ECS Inc. ZTT-20.00MX resonator. It has build in capacito= rs=20 and > thus I am connected it directly to the PIC, but the PIC doesn't work. = I > have a 4.0 MHz resonator (says ZTT on it) and the PIC works with it. = Any > suggestions? Is there anything that needs to be changed when swapping= > resonators? I am testing with a simple piece of code that blinks an L= ED=20 at > 1s (though this would be much faster at 20MHz). > Thanks, > Donovan Parks -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics