> Wouter's basic idea is sound. A single pin interface... > Note the name, " *ZERO* Pin Loader". > Wouter uses the MCLR pin, not an I/O pin. Confusion here: I have two bootloaders on my website: WLoader is a more-or-less standard one-I/O-pin bootloader for 16F877(A) and relatives, ZPL is a zero-I/O-pin loader (using /MCLR) for teh 18F452 and relatives. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: www.voti.nl consultancy, development, PICmicro products -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics