>> No. Some processors do not support ISP. > But aren't those all the older "C" parts? You are probably correct - your knowledge in this area is vastly (actually several times vastly :-) ) greater than mine. If you can't think of one then I'm almost certainly wrong. RM -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist