Parts list and buy links: • 28-pin DIP IC Socket - $0.30 - buy mouser • 16MHz crystal - $0.55 - buy mouser • momentary push-button switch - $0.15 - buy mouser • 1k ohm resistor - $0.05 - buy mouser • LM7805 5v voltage regulator - $0.35 - buy mouser • 2 x 22pF capacitors - $0.12 - buy mouser • 10nF capacitor (ceramic disc code '103') - $0.10 - buy mouser • 22uF capacitor - $0.02 - buy mouser • ATMe