Someone (jims cool) on Nesdev's forum was busy doing the same thing with a attiny13 except he's planning to have it work both as NES CIC and SNES CIC as far as I remember. Impressive that you managed to do it in 3 days! It's always nice seeing AVR get some love:0 Will you be releasing the binary or you are planning on setting the protection fuse and keeping it private? (just curious, no judgments!)