Atmel AT89C2051 microcontroller (or AT89C1051, AT89C4051)
AT24C512 serial EEPROM chip (or compatible)
12 MHz crystal
2 x 33p capacitor
10 uF capacitor
10 k resistor
small push-button
Nebo pokud je šikovnej, tohle jde sehnat do dvou kil i s nanukem