I want to protect my pic code from copying. The device is 18f4550. Which are the ones to activate - CP0-CP3 or WRT0-WRT3 or EBTR0-EBTR3 ? Beckie. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist