Hello PIC.ers, This is probably simple to answer. uchip `sort of' cover it in data sheets and the ICD help files but all I see is ambiguity. I need to reset all data EEPROM to 0x00 when programming the 16F877 using the ICD. Apparantly ticking the box: Program Option > Erase All Before Program is supposed to ensure this. Usually, it does. *But* I have at least two devices, each reprogrammed many times which refuse to reset. The data EEPROM area has scarcely been used at all and the program otherwise runs perfectly. Any clues? best regards, John e-mail from the desk of John Sanderson, JS Controls. Snailmail: PO Box 1887, Boksburg 1460, Rep. of South Africa. Tel/fax: Johannesburg 893 4154 Cellphone no: 082 741 6275 email: jsand@pixie.co.za Manufacturer & purveyor of laboratory force testing apparatus, and related products and services. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.