Konrad Zuse. Biography. Contributions. Zuse-Companies. Z3r. Tour-Zuse-Computer. Z23 Crosses Altlantic. Early Computers. Neumann vs Konrad Zuse. Impressum and Contact. Professor Dr.-Ing. habil.
Horst Zuse

Zuse KG (1949-1964)

In 1949 Konrad Zuse founded the Zuse KG with five employees in Neukirchen (Kreis Hünfeld, 120 km north of Frankfurt). The building in Neukirchen (Kreis Hünfeld) was formerly a trading post.

In this building the first computer company in Germany was founded by Konrad Zuse. It was an old trading post. There the Z4 was restored and the Z5, Z11 and Z22 were constructed there.

The first task of the Zuse KG in 1949 was to restore the Computer Z4, which survived the air attacks of the allies in Berlin and on the way from Berlin to Hinterstein (Allgäu). In 1949/50 the Z4 was extended by the following features and delivered to Zürich on July 11, 1950:

* Conditional branch.

* Instructions for printing the results on a Mercedes typewriter.

* Storing numbers on the punch tape in order to transfer them into the memory of the Z4.

* Restoring the furniture.

* Separation of the service unit and the relay cupboards.

The restored Z4 in Neukirchen Kreis Hünfeld in 1950. The Z4 consisted of ca. ten relay cupboards with 2200 relays. The memory was a mechanical one with 64 words a 32 bits. The processor was a very powerful floating processor. The image above is linked to an enlargement (150 KB).

The Z4 was a big machine with 2200 relays and a memory of 64 words á 32 bits consisting of metal sheets.

[Restoring the Z4 charged the Zuse KG with approx. 60,000 DEM, but the ETH Zürich paid for the Z4 an amount 40,000 CHF. With this money it was possible to found the Zuse KG and to restore the Z4. The Z4 was a great success for the ETH and the Zuse KG. The speed of the Z4 was about 1000 instructions per hour.

In 1950, the Leitz Company in Wetzlar ordered a big relay computer, the Z5. The picture shows the employees of the Zuse KG in 1952, who built the Z5. The Z5 also was a great success for the Zuse KG. The Z5 was sold for 300,000 DEM.

The Z5 was an extended version of the Z4. Konrad Zuse used modern relays in order to overcome the bad reliability of tubes. The Z5 was the first commerial computer in Europe.

However, the Z5 was the only one big mandate, that the Zuse KG got between 1949 and 1955. After the second world war the situation in Germany and Europe was very difficult. The companies had no money to buy computers. Germany was destroyed up to 60%. The capacity of the German economy was less than 20% compared to 1939. For this reason, Konrad Zuse tried to make some business with US companies. He successfully made some business with the Remington Rand Corporation. Till 1955, in Germany was no support by the government for buying or building computers in a company. An exception was the construction of the G1 in Göttingen, which was a research computer. From 1955 the DFG (Deutsche Forschungsgemeinschaft) gave money to install computers in the universities. The computer Z11, a relay computer, was sold from 1955 to German companies, mostly to the optical industry and universities. In 1957 the universities started to order computers of the type Z22. This was a very flexible and cheap computer based on tubes with a drum of OK words. After 1957 many other computers followed, for that see Konrad Zuse computers.

Early in 1955 Konrad Zuse began with the development of the Graphomat Z64. It was a drawing machine with an accuracy of 0.05 mm. This machine was controlled by a program created by the Computers Z22, Z23, Z25, or Z31.

The Zuse Graphomat 90 in 1964. The image above is linked to an enlargement (300 KB).

From 1949 to 1969, the Zuse KG produced more than 250 computers with a value of 100 Million DM. Although in 1964 the Zuse KG had orders of more than 25 Million DM, it was for Konrad Zuse impossible to keep the Zuse KG as his own company. The next picture shows the Zuse KG (1200 employees) in 1964 in Bad Hersfeld.

After 1961 the Zuse KG got more or less in financial trouble. There were many reasons for that:

* There was no financial support of the computing industry by the government.

* There were an increasing competition by IBM and other computer manufactures.

* The patent situation of Konrad Zuses computers were not solved at this time. A decision of Konrad Zuse patents were made in 1967.

* Mismanagement.

* Too fast growing of the company.

* Software unbundling. The development of software charged the company more and more, but the customer did not want to pay many for that.

* No financial spares because computers were the only production subject.

* Software production costs.

In 1964 the Zuse KG was bought by Rheinstahl, then by BBC und finally in 1967 completely by the Siemens company. In 1969 the logo Zuse KG was deleted. Konrad Zuse left in 1969 the Zuse KG.

From my view, Konrad Zuse is not a collapsed entrepreneur. It is easier to criticize people than to make it better. Konrad Zuse was years ahead with his company, computers and ideas related to computers.


Zuse KG 1949
Machine Z4, saying good bye to Zürich (1950).
Machine Z5 forthe Leitz Company in 1953.
Zuse Graphomat Z64 (1961)
The Zuse KG delivered 251 Computer of an value of 102 Million DM from 1949-1969.
In 1964 the Zuse KG had 1200 employees.