Hi, I am having a problem successfully programming a 18F452 with code I have written. I am using a wisp628 which flawlessly programs the chip with example flashing light code (not mine) the programmer has also successfully programmed other chips (but I have not tried with my code) The programmer seems to program & verify the code OK only falling over verifying the fuses. I see an error on the python console of the location 300000 reading back as 00 when it should be FF (I am quoting the numbers from my increasingly fallible memory) I suspect that MPASM is doing something interesting with my __CONFIG entries - in a moment of desperation I copied them fresh from the p18F452.inc file (that was shipped with MPLAB) I have tried copying what I thought was the fuses line from a working file and that seemed to work - however it would be nice to be able to use *my* selections :) MPLAB is ver 6.12.0.0 running over win2k. One thing that makes it more complicated is my data sheet pin diag for the DIP indicates pin 38 is PGM, with a note that it should be pin compatible with the PIC16F7X devices - I left the PGM cable from the wisp in pin 36 (as the wisp doco suggests is correct) and it seems to successfully program - at that point I decided that the wisp doco probably got preference over the data sheet.. Thanks for your help. Antony W. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics