Hello all, I think someone else has ask this question before, but I didn't read any answers. What kind of crystal do we need for building the extern part of the oscillator for a PIC: serial or parallel ?? I am using a 8 MHz crystal, with two C's of 15 pF to ground as described in the databooks of MicroChip, now for one of my applications, but the crystal seems to run at a slightly higher frequence. For getting the correct frequence I have to increase the C's value to about 40 pF. Does someone can help me? Buy, ... Sipke de Leeuw ...