1940 to 1949: Computing During World War II and the Postwar Era - The Technical and Social History of Software Engineering - page 48

Analog computers would continue to be the workhorses of ships at sea and air-
craft in combat on through the Korean War and into the Vietnam conflict. Digital
computers and embedded software would not fully replace analog computers as
weapons systems until the 1980s.
Those of us in software owe a debt of gratitude to the analog computing en-
gineers and designers who built devices such as the Norden bombsight, the British
“bombe” for cryptanalysis, and the Mark III Torpedo Data Computer (TDC) used
on American submarines. These analog computers played a major part in the Al-
lied victory of World War II. The history of military analog computers is as im-
portant as the history of digital computers.
Computers in Germany During World War II
It is fortunate for the United States and the Allies that the German military did not
place a high priority on digital computers, even though one of the major pioneers
in the history of computing, Konrad Zuse, lived in Berlin and developed several
working computers between 1940 and 1945. He even designed what is probably
the first programming language, called Plan Calculus (or Plankalkuel in German)
in 1945. This language was not supported by a working compiler, however.
Zuse started as an aeronautical engineer at the Henschel Aircraft Company in
1935. Zuse soon left full-time work and set up a computer laboratory in his par-
ents' apartment in Berlin. He continued to work part-time at Henschel. In 1938,
Zuse built his first prototype computer, the Z1, to prove the concept of machine
computation. This first machine did not work well due to mechanical issues.
In 1940, Zuse built the Z2 computer, which did work and was probably the first
operational electromechanical computer built in the world.
In 1941, Zuse built the Z3, which was an operational electromechanical com-
puter based on binary digits. The German military used the Z3 to calculate wing
flutter in combat aircraft. Zuse requested funds to build a fully electronic version,
but his request was denied as “not being important to the war effort.”
In 1945, Zuse completed the Z4, which had a number of technical advances.
It used binary arithmetic and could be programmed using paper tape as the input
method. The Z4 could also produce printed output. It was used to solve mathem-
atical calculations and could also handle conditional branching logic. The Z4 was
a major contender for being the first successful digital computer. Due to the ad-
vance of Russian troops on Berlin, the Z4 was shipped to safer locations several
times, which slowed final developments. After World War II, the Z4 was acquired