Thank you so much. That works perfectly!
You are welcome! I'm glad it worked.
@westfw, you are also welcome!
One query, you said ... ADABoot_644p.hex ... But the supplied bootloader files are actually ... ATmegaBOOT_644P.hex
Does that mean the bootloader directory...
That is one sharp eye you have! You are welcome to change the directory name as you see fit. Just change the entry in boards.txt to match...
and/or the boards.txt file should be modified to suit the file names?
The entry in boards.txt needs to be changed to match the filename...