Russell McMahon wrote: >> Is it possible to make a very simple circuit to program EVERY 16F >> and 18F pics using ICSP ? > > No. Some processors do not support ISP. But aren't those all the older "C" parts? I haven't looked at the programming specs for all 16F and 18F parts (there are far more programming specs than you might think if you've never looked into this), but it was my understanding that these subset of PICs all support serial programming with Vpp, PGC, and PGD. Can you point out a 16F or 18F that does not? ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist