Between 1936 and 1938 a young German engineer named Konrad Zuse – who was born on June 22 1910 in Wilmersdorf and later lived with his family in Kreuzberg – was busy re-decorating his parents’ living room. It happened in a house which used to stand in today’s Methfesselstraße No. 10 – sadly, the building fell prey to one of the Second-World-War air-raids.

The refurbishment was taking place with the parents’ consent as well as their financial support but hardly any grasp of what was happening under their roof. Their home became a headquarters of mad scientists with Konrad as the commander-in-chief, his good friend and fellow engineer, Helmut Shreyer, as deputy; Zuse’s older sister, Liselotte (who according to Zuse was “unlucky enough to be born in those times as an intelligent person and as a woman“) as his right hand and a group of the scientist’s little helpers from A.V. “Motiv” (an academic society at Berlin’s Technical University). The living room was rendered completely unusable for its usual purposes by something that was to become the dawn of modern computing.

Z1 in the living room of Zuse’s parents’ flat (source:

It was a spreading mechanism built around a metal frame, using hundreds and hundreds of thin metal plates (invented and patented by Zuse himself and manufactured by the group working on the project) and powered by a single electric motor – one which had been “borrowed” from the family vacuum cleaner. The machine – meant to do what the inventor himself was so loathe to, namely perform boring, time-consuming engineering calculations – was to be programmable. To that end, Zuse used a simple but ingenious trick: programme was fed into the machine with the help of strips of punched film tape. That machine was we what refer to as a computer.

Konrad Zuse holding one of the key elements of his early computer (photo: AP)

And not just any computer: what was later named Zuse 1 or Z1, used the binary – the “1-0” – system. Our tablets, smartphones, PCs and notebooks are far descendants of Zuse’s metal wonder. And like with all forefathers and foremothers of Progress this one, too, was far from perfect. The original Z1 did work but being a mechanical thing made of not always perfectly manufactured elements, was prone to jamming and thus to producing false results.

However, is it now it exactly how progress works? With the imperfect first edition being soon replaced by its improved version? Konrad Zuse knew Z1 had not been what he had wished it to be. Soon enough, he had another project in progress that would go down in history as Z2. Then came his Z3 – created in Methfesselstraße 7 (where a half-ruined section of the facade wall of the building has been preserved until today) as the first working programmable computer in the world, followed by a Z4 soon afterwards. Of course, both were then overtaken by smarter devices – which, however, in no way lessens the amazing significance of Zuse’s discoveries.

Konrad Zuse (l) and Helmut Schreyer (r) working out the details of their project.

Today Z1 with its 32 bytes of memory and a 1Hz clock – that means one cycle per second as opposed to the 2.4 Gigaherz these words are being “penned” with – could hardly be considered impressive. Still, so great was its impact that when the original mechanism and the whole documentation were destroyed along with the house where Zuse’s workshop was located at the time, it was considered to be a disaster in the history of computing sciences.

Not surprisingly, years later a decision was made to have the machine reconstructed. And only one person in the whole world was capable of doing it right: the master himself. Konrad Zuse began building the replica of Z1 in 1986, again making most of the parts himself. It lasted almost three long years.

Replica of Z1 at Berlin’s Technikmuseum (image by ComputerGeek at Wikipedia)

Today it can be seen at the Technology Museum in Berlin-Kreuzberg (Trebbiner Straße 9, U7 Gleisdreieck). In Methfesselstraße 7 a plaque commemorates the doggedness of one inventor, the endless patience of his parents and the astounding fate of one living room.


Konrad Zuse and his inventions are featured in an audio-tour of West Kreuzberg created by yours truly and available via under this link.