Z3 Adder (reconstruction) 1941 Konrad Zuse, Germany Konrad Zuse’s Z3 was the world’s first automatic, electromechanical computer. It was controlled by holes punched in used 35mm movie film. This relay board is a modern reconstruction of one of its binary addition units. It is an interactive model that has two 10-bit registers and shows the intermediate computation state via a set of lamps. The Z3 featured two binary adders constructed with telephone relays and was able to perform floating-point arithmetic on 22-bit numbers. The complete machine contained 2,600 relays and had a memory of 64 words.