Is ATMega 168A-PU compatible (physically) for boot loading arduino? If so, I always get an invalid device signature error when trying to bootload it from within the arduino IDE? How to successfully bootload it?
I am selecting the arduino NG or older board and is this IC physically compatible to handle arduino or am I just wasting my time?
Yes, of course, or the Atmega168 wouldn't be on the list. Perhaps if you describe in more detail. Your first post told us practically nothing. What programmer device are you using? What board are you using? Did you make it yourself? What is the wiring? Are you using a crystal? Photo please.