Konrad Zuse's computers
From 1935 to 1938 Konrad Zuse designed and built the world's first programmable computer also known as the Z1. The Z1 was a binary electrically driven calculator, hence had some flaws but was the making of something special. The Z1 was a 22-bit machine which could add and subtract. With assistance perform more complex calculations such as multiplication and division. Konrad's first Z1 was destroyed in the bombings of world war II. The Z1 contained the basics of a modern computer such as the control unit, memory, micro sequences, floating point logic and input output devices.
In 1939 Zuse built a mechanical and relay machine known as the Z2 which was an improvement of the Z1. Konrad Zuse was helped financially by Dr. Kurt Pannke as he himself manufactured small calculating machines.
The Z2 was showing signs of improvement therefor Zuse got the financial help to design and build the Z3 computer, he did so from 1939 and finished in 1941. The Z3 was the first automatic, program controlled, fully functional, general purpose computer.
Zuse started building the Z4 in 1943 and finished construction in 1945. He was funded by the German air ministry. The Z4 was the first sold computer. Zuse founded Zuse KG(his own company) with five employers.
Konrad Zuse is credited to contribute the fundimental of using the binary system for numbers and circuits. Zuse is also credited for creating the first programming language such as Plankalkul. He is also credited to contributing the pseudo-memory, special values, algorithm for the non restoring calculation for the square root.
Here is a link to a website with all of Konrad Zuse's contributions to the modern computer: