no, there is only one initial eeprom write during flashing the PIC, then only once again if mode is changed, which usually never happens and if, the= n months or even years may have gone by. As said, I'm initializing cell #0 to $00 for mode 1 and that's it. To answer another question: No, there is only address #0 written and read, all other cells are unused. A question from my side to this: Does "fail" mean here, that the eeprom cel= l is falling back to $FF or is it possible, that it has any random value afte= r "failing"? Peter I'm not sure, but did yo ever reply to the question about if there was any other writes to the EEPROM during production use ? One major questions is, does the EEPROM fail during read-only use or due to missing "refresh" ? -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membershi= p options at http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .