How it began
Konrad Zuse, a German engineer, designed the Z3 in 1938 and completed it in Berlin in 1941. The Computer History Museum notes that he worked in complete isolation from developments elsewhere. The machine was originally called V3, for Versuchsmodell 3 or Experimental Model 3, and was later renamed so that it would not be confused with Germany's V-weapons.
How it works
The Z3 was built from relays, about 2,300 by the Computer History Museum's count. It performed floating-point binary arithmetic with a 22-bit word length and ran at a clock frequency of about 5 to 10 Hz. Program code was stored on punched film, and initial values were entered by hand. It lacked conditional branching.
Who pushed back
The Z3 was not considered vital, so it was never put into everyday operation. Zuse asked the German government for funding to replace the relays with fully electronic switches, but the request was denied during World War II because such development was deemed not important to the war.
What changed first
The machine was used for aerodynamic calculations. Based on the work of the aerodynamics engineer Hans Georg Küssner, a program to compute a complex matrix was written and used to solve wing flutter problems. The original Z3 was destroyed on December 21, 1943, during an Allied bombardment of Berlin.
What lasted
Because of the Z3 and its predecessors, Zuse has often been suggested as the inventor of the computer. In 1998 the Z3 was demonstrated to be, in principle, Turing-complete, although only by computing all possible outcomes of a calculation, since it had no conditional branching. Zuse's company, Zuse KG, built a fully functioning replica in 1961 under his supervision. It is on permanent display at the Deutsches Museum in Munich.
