> > It appeared to work (delay loops, some I/O etc) at > > 78.6432MHz > > Have you measured that using a digital or an analogic scope ? > Are you sure the PLL locked on fundamental oscillation ? Analogue scope showed 78MHz. And everything executed twice as fast, so the silicon wasn't fooled at all -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist