There is excellent coverage of hardware designs consideration for ICSP in the help file that comes with PICALLW. www.picallw.com Some of it is software specific, but the hardware considerations should apply to most programmers I think it's under Technical Information>In Circuit System Programming(ICSP)>ICSP and Picall/P16Pro Lyle Hazelwood -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads