Konrad Zuse (1910 – 1995)

If one only pays attention to the Anglosphere, one would believe that the British in the persona of Charles Babbage (1791–1871) with his Difference Engine (1820s) or possible Tommy Flowers (1905–1998) who led the construction of Colossus (1943 – 1945) or the people at the University of Pennsylvania who made ENIAC = Electronic Numerical Integrator and Computer (completed 1945), invented computers. Most often the definition of first is prefaced by a specific type of technology, that by definition eliminates other worthy competitors.

Here I would like to direct attention to Konrad Zuse (1910 – 1995), a German civil engineer, computer scientist, inventor and businessman. One reason for the failure to include Zuse as the real inventor of the computer is that he worked for the Germans (read Nazis), during World War II. This is not a politically correct story about the invention of computers. Far too many sources offer a bowdlerized version = the removal or altering of parts of a text that are considered offensive or vulgar, often to make it more suitable for a particular audience. The term originates from Thomas Bowdler (1754 – 1825), who published a censored edition of Shakespeare’s works.

Konrad Zuse was born in Berlin. In 1912, his family moved to East Prussian Braunsberg, now Braniewo, Poland, where his father was a postal clerk. Zuse attended the Collegium Hosianum in Braunsberg, and in 1923, the family moved to Hoyerswerda, where he passed his Abitur in 1928, qualifying him to enter university.

He enrolled at Technische Hochschule Berlin = Technische Universität Berlin (current name). He studied engineering and architecture, but found them boring. He graduated as a civil engineer in 1935.

Zuse then worked for the Ford Motor Company, using his artistic skills for advertising. Later, he started work as a design engineer at the Henschel aircraft factory in Schönefeld near Berlin. This work required him to undertake many calculations by hand, leading him to theorize and plan a way of doing them by machine.

Beginning in 1935, he experimented in the construction of computers in his parents’ apartment. In 1936, he produced Z1, a floating-point binary mechanical calculator with limited programmability.

In 1937, Zuse was advised to use vacuum tubes as switching elements, but, at the time, considered it a crazy idea. In 1937, Zuse submitted two patents that anticipated a von Neumann architecture computer. In 1938, he finished the Z1 which contained some 30 000 metal parts. It never worked well due to insufficient mechanical precision. In 1944, the Z1 and its original blueprints were destroyed with his parents’ flat and many neighbouring buildings by a British air raid in World War II.

In 1939, Zuse was called to military service, where he was given the resources to ultimately build the Z2. In September 1940 -09 Zuse presented the Z2 to experts of the Deutsche Versuchsanstalt für Luftfahrt (DVL) = German Research Institute for Aviation.  The Z2 was a revised version of the Z1 using telephone relays.

Much of his early work was financed by his family, but after 1939 he was given resources by the government of Nazi Germany.

In 1940, the German government began funding him and his company through the Aerodynamische Versuchsanstalt (AVA) = Aerodynamic Research Institute, forerunner of the Deutsches Zentrum für Luft- und Raumfahrt (DLR) = German Aerospace Centre, which used his work for the production of glide bombs.

Zuse built the S1 and S2 computing machines, which were special purpose devices which computed aerodynamic corrections to the wings of radio-controlled flying bombs. The S2 featured an integrated analog-to-digital converter under program control, making it the first process-controlled computer. The circuit design of the S1 was the predecessor of Zuse’s Z11. Zuse believed that these machines had been captured by occupying Soviet troops in 1945.

In 1941 Zuse started a company, Zuse Apparatebau = Zuse Apparatus Construction, to manufacture his machines. That same year he improved on the basic Z2 machine, and built the Z3, a machine that was built in his workshop and presented to the public on 1941-05-12. It was a binary 22-bit floating-point programmable calculator with memory and loops but without conditional jumps based on telephone relays. These relays were largely collected from discarded stock. This was the world’s first fully operational electromechanical computer, was partially financed by DVL which wanted to automate their extensive calculations.

He designed the world’s first programmable computer, the Z3, a functional program-controlled Turing-complete machine that became operational in 1941-05. He also developed the S2, the first process control computer. In 1941, he founded one of the earliest computer businesses, producing the Z4, which became the world’s first commercial computer.

Zuse had begun constructing the Z4 in 1942. These machines contributed to the Henschel Werke Hs 293 and Hs 294 guided missiles developed by the German military between 1941 and 1945, which were the precursors to the modern cruise missile. The Z4 also served as the inspiration for the construction of the ERMETH, the first Swiss computer and one of the first in Europe.

On 1945-02-03, aerial bombing caused devastating destruction that effectively brought Zuse’s research and development to a complete halt. The partially finished, telephone relay-based Z4 computer was then packed and moved from Berlin to Göttingen.

After this bombing, Zuse fled Berlin for rural Allgäu. However, in the extreme deprivation of post-war Germany Zuse was unable to build computers.

While working on his Z4 computer, Zuse realised that programming in machine code was too complicated. From 1943 to 1945 he designed Plankalkül = Plan Calculus, the first high-level programming language. His PhD discertation detailed this programming language. As an elaborate example program, he constructed the first computer chess engine.

Zuse founded one of the earliest computer companies: the Zuse-Ingenieurbüro Hopferau. Capital was raised in 1946 through ETH Zurich and an IBM option on Zuse’s patents.

In 1947, there was a colloquium in Göttingen. In addition to Konrad Zuse, participants included: Alwin Walther (1898 – 1967),, John Womersley (1907 – 1958), Arthur Porter (1910 – 2010), Alan Turing (1912 – 1954), Helmut Schreyer (1912 – 1984) and Heinz Billing (1914 – 2017).

In November 1949, Zuse founded another company, Zuse KG. One of its first tasks was to restore and improve the Z4. He would show the computer to the mathematician Eduard Stiefel (1909 – 1978) of the ETH Zurich. The two men agreed to lend the Z4 to the ETH. It was delivered to the ETH Zurich in 1950-07. It proved to be very reliable. The company produced over two hundred and fifty computers from 1949 to 1969. Other computers, all numbered with a leading Z, up to Z43, were built by this company. Notable are the Z11, which was sold to the optics industry and to universities, and the Z22, the first computer with a memory based on magnetic storage.

In 1956, Zuse began to work on a high precision, large format plotter. It was demonstrated at the 1961 Hanover Fair,[46] and became well known also outside of the technical world thanks to Frieder Nake’s pioneering computer art work.[47] Other plotters designed by Zuse include the ZUSE Z90 and ZUSE Z9004.[46]

In 1967, Zuse suggested that the universe itself is running on a cellular automaton or similar computational structure (digital physics); in 1969, he published the book Rechnender Raum (translated into English as Calculating Space).[16][17][18]

In 1969, Zuse suggested the concept of a computation-based universe in his book Rechnender Raum = Calculating Space. An elementary process in it involve two digital particles A and B form a new digital particle C.

Between 1987 and 1989, Zuse recreated the Z1, despite a heart attack midway through the project. It cost 800 000 DM = ca UA$ 500 000. ) Four people (including Zuse) were needed to assemble it. Funding for this retrocomputing project was provided by Siemens and a consortium of five companies.

Between 1989 and 1995, Zuse conceptualized and created a purely mechanical, extensible, modular tower automaton Helixturm = helix tower. The structure is based on a gear drive that employs rotary motion (e.g. provided by a crank) to assemble modular components from a storage space, elevating a tube-shaped tower; the process is reversible, and inverting the input direction will deconstruct the tower and store the components. In 2009, the Deutsches Museum restored Zuse’s original 1:30 functional model that can be extended to a height of 2.7 m. Zuse intended the full construction to reach a height of 120 m, and envisioned it for use with wind power generators and radio transmission installations.

While Zuse never became a member of the Nazi Party, he is not known to have expressed any doubts or qualms about working for the Nazi war effort. Much later, he suggested that in modern times, the best scientists and engineers usually have to choose between either doing their work for more or less questionable business and military interests in a Faustian bargain, or not pursuing their line of work at all.

Note: The weblog post was started on Friday, 2025-01-24, at 21:30. It was completed on 2025-11-30, at 12:30.