> > > That does not determine if write protection is on or not. In many pics > there is a config option to protecta section of low memory for the > bootloader. The question is twofold: Do you have a pic with such an optio= n > and do you have that option turned on? > > BAJ Ok, now I understand. The 18F2550 has a configuration bit to write protect the boot block (first = 2 KByte) and I didn't enable it. I think this feature and enabling the brown out reset wil solve my problem. Thank you Cristiano --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .