Hi Neil, The part you are having trouble with is a PIC16F627 not a PIC16F627A correct? The reason I'm asking is because the PIC16F62XA has an errata problem with EEPROM writes. Just checking with you. Best regards, Ken Pergola -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu