> The transcript of a write session is below. I'd appreciate any advice > on how to proceed, since I'm at a loss. things to check/do - check contacts between the PGM/PGD pins out of the Wisp628-PIC right up to the target PIC (I have heard from people who had a hairline crack in their PCB and got intermittent results due to capacitivi/high-resistive coupling) - make sure the wires are short - is your +5V realy 5.0 Volt? - after the writing fails, read the chip. what is the content of the failing location? - try GO instead of WRITE Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: www.voti.nl consultancy, development, PICmicro products -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.