=20 > I want to use standard chip programming hardware: PICkit3 or ICD3 in=20 > standard High-Voltage programming mode. However, I don't know if it=20 > is necessary for power to be removed from the PIC before the=20 > programming sequence starts. Removing power is not necessary. Make sure that you are not powering the target from PICKit3, there is a setting in the programmer software (at leas= t in the IPE). I believe you can also not connect programmer's power line to the target. =20 Sergey --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .