Ok, well I've looked back 10 pages this forum and haven't found the answer. I have a couple of 12c508 lying around (blank) and have a programmer. What I am not sure is what hex file to put in it. I have found many. I think I want MM3.hex in it, but I don't know what wiring diagram to use. I have 9xxx version. The best I found was a 7 wire diagram labeled PU23, but not sure if the hex will work with it.