AVR links

http://www.engbedded.com/fusecalc/

http://projectsfromtech.blogspot.com/2013/04/using-reset-pin-as-io-on-attiny8545.html

http://www.simpleavr.com/avr/hvsp-fuse-resetter

http://www.rickety.us/2010/03/arduino-avr-high-voltage-serial-programmer/