H used an IC testing clip to make a simple adapter for programing ATmega microcontrollers on the fly. IC test clips are tools used to grip ICs and provide easy connection to the pins.
I’ve got a different use for it though. If you develop a circuit using an Atmega chip (like, say, a circuit you developed with an Arduino but have now moved to a custom board), reprogramming the chip is fiddly. The best way to make your circuit easily re-programmable is to build an ISP header onto your board – it’s just a 6-pin connector that lets you blast new programming onto the chip without removing it from the circuit.
Most of my little circuits don’t have room for the 6 pin connector though, and it’s a hassle to hook up the 6-pin programming connections when you’ll hopefully never have to reprogram the things anyway.
To program the chips on these boards you have to lever the chip out, stick it in a programmer and then stuff it back into the circuit board again. Not the most difficult thing to do, but it can get a bit fiddly, and it’s always a bit dangerous trying to lever the chip out without damaging the chip or the board. The test clip fits over all the pins you need access to for programming though.
Via Electronics-Lab.