This unlocked such fond memories, I'll buy some just to make some LEDs blink. I am glad my first exposure to embedded systems was through ATmega series, not for the chip, but the user's manual. That is perhaps the only manual I have read cover to cover, that thing took me to knowing rudimentary electronics to actually understanding a full system. The first real world system I could hold fully in my head, and that was an amazing feeling. Who ever wrote that, hats off. I remember then encountering the ARM manual which had similar clarity of writing. Were there like professional writers for these things?