That's point out again Bruce. Since i've never never use that WRITECODE it answer to some of my assumption then.

Peter, if you have any extra i/o and you dont want to change PIC, you can also use a i/o to monitor your supply line. If there's any failure, use an little 3volt battery backup to supply only the PIC. When you'll get any power failure drop the PIC into SLEEP mode an wait for power comes up. That could be a easy solution here.