I’m frequently using 6-pin ISP for programming on a breadboard and don’t actually have the pin-header on the target. This allows me to look at the bottom of the board and the bottom of the IDC ...

The first part of the trick hinges on his use of PDI programming. This is slightly different from ISP programming. Both use a six-pin connector cable but with PDI two of these pins are unused.

This enavbles programming through a different interface (usually a Serial port), and is very commonm in Arduino circles. Unless countermeasures have been taken aginst it, they can also be reprogramed ...

This enavbles programming through a different interface (usually a Serial port), and is very commonm in Arduino circles. Unless countermeasures have been taken aginst it, they can also be reprogramed ...