> Programming a PIC in circuit isn't done by itself. > (snip some calculations) I fully agree with Olin's 'calculated' approach, but I think in some cases (often?) there will be some non-zero extra circuit cost to accomodate the ICSP (isolation resistors, board area for connections). This cost would favour pre-programming. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: www.voti.nl/hvu -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist