> I've got some that I suspect are not working. 20MHz > crystal oscillators. Besides actally trying to use > them, is there a way to test & see if they are working? If you did mean an actual crystal, you have _HS_OSC in CONFIG ? Or alternatively, not trying _HSPLL_OSC with an 18F ? (10MHz is the limit for PLL) -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist