Harold Hallikainen wrote: > Do we really need to isolate the Vdd supply from the rest of the circuit > so it can be pulled up to 5V for ICSP? Generally yes. http://www.embedinc.com/picprg/icsp.htm ****************************************************************** Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC consultant in 2004 program year. http://www.embedinc.com/products -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist