> squeeze some more speed out The USB-capable PICs like the 18F4550 have a 24x PLL to make an internal reference of 96MHz from a 4MHz crystal. The fastest the PIC can run though is 48MHz, 20% faster than a 40MHz part wbr -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist