1.3 Generation of computers
Five Generations of Modern
First Generation (1945-1956)
With the onset of the Second World War, governments sought to develop
computers to exploit their potential strate.g.ic importance. This increased
funding for computer development projects hastened technical progress. By 1941
German engineer Konrad Zuse had developed a computer, the Z3, to design
airplanes and missiles. The Allied forces, however, made greater strides in
developing powerful computers. In 1943, the British completed a secret
code-breaking computer called Colossus to decode German messages. The
Colossus's impact on the development of the computer industry was rather
limited for two important reasons. First, Colossus was not a general-purpose
computer; it was only designed to decode secret messages. Second, the existence
of the machine was kept secret until decades after the war.
American efforts produced a broader achievement. Howard H. Aiken
(1900-1973), a Harvard engineer working with IBM, succeeded in producing an
all-electronic calculator by 1944. The purpose of the computer was to create
ballistic charts for the U.S. Navy. It was about half as long as a football
field and contained about 500 miles of wiring. The Harvard-IBM Automatic
Sequence Controlled Calculator, or Mark I for short, was a electronic relay
computer. It used electromagnetic signals to move mechanical parts. The machine
was slow (taking 3-5 seconds per calculation) and inflexible (in that sequences
of calculations could not change); but it could perform basic arithmetic as
well as more complex equations.
Another computer development spurred by the war was the Electronic
Numerical Inte.g.rator and Computer (ENIAC), produced by a partnership between
the U.S. government and the University of Pennsylvania. Consisting of 18,000
vacuum tubes, 70,000 resistors and 5 million soldered joints, the computer was
such a massive piece of machinery that it consumed 160 kilowatts of electrical
power, enough energy to dim the lights in an entire section of Philadelphia.
Developed by John Presper Eckert (1919-1995) and John W. Mauchly
(1907-1980), ENIAC, unlike the Colossus and Mark I, was a general-purpose
computer that computed at speeds 1,000 times faster than Mark I.