The Computer Revolution

The Personal Computer - a technology revolution
Fasttrack to America's Past

Return to Originating Page

The world's first electronic computer was invented in 1946, during World War Two.
It was developed at the University of Pennsylvania as part of a U.S. Army project
to speed up complex mathematical calculations for weapons design.

The computer, shown below, was called the ENIAC - short for Electronic
Numerical Integrator and Calculator.

Women mathematicians and programmers were a key part of the team that ran
the ENIAC computer. The system began operating in 1946, and remained
in service until the mid-1950s.

Below: A computer used by the military in the 1960s. This was a big
advance over the ENIAC computer system, but like all computers of that
time, it was large, very expensive, and complicated to operate.

In the 1970s, advances in computer technology led to the first steps toward
small and affordable computers. The Altair 8800 model shown below was first
sold in 1975, mainly to engineers and hobbyists interested in learning more
about computers. It could run only very simple programs, which were
entered one command at a time using the switches on the front panel.
The results were displayed on the lights on the front panel.

By the 1980s, companies like Apple and IBM were developing small computers
that could do word processing, solve complex math formulas, and run simple games.
The photo below shows an IBM Personal Computer of that time. As the price of small
computers fell below $1,500 during the 1980s, many American families began buying them
for home use. By the year 2000, slightly over half of American homes had a computer.

Below: The electronic devices that make small and powerful home computers possible.
At top is a strip of computer memory chips. The chips can hold millions of numbers
or words in digital form. Also shown is the microprocessor, the device that does
the actual computing. Under the metal cover are millions of tiny electronic
circuits shrunk down to microscopic size onto a small chip of silicon.

The ENIAC photo at the top is from the Library of Congress.
The ENIAC photo with women programers, and the
photo below it, are from the U.S. Army.
The photo of the Altair 8800 is from by
Michael Holley, from Wiki Commons.
The photo of the IBM PC is from Wiki Commons.
The photo of the computer parts is by David Burns.