Computer history timeline

• Blaise Pascal’s father was a tax officer. The two of them
would spent hours together trying to figure out the taxes
each French citizen owes the government. Pascal
decided to invent a machine to do the math for them.
This resulted in La Pascaline, which could add and
subtract with a set of eight gears. This machine was
never very popular, because it often broke and was slow.
There is a computer language named Pascal in his
• This German mathematician
built the Leibniz Calculator a
few years after La Pascaline.
It could add, substract,
multiply, divide and even find
square roots. Although this
machine was never
manufactured, almost every
mechanical calculator in the
next 150 years was made
similar to it
• This Frenchman built a machine
for the weaving industry that could
be programmed through sets of
heavy cardboard punched cards.
The cards for one weaving design
were linked together. When they
passed through the loom, a set of
rods in the machine were guided
by the cards to make the design.
Even though other weavers were
already using punched cards for
their looms, the Jacquard Loom
refined the ideas.
• Charles Babbage was a mathematics
professor at Cambridge University. The tables
he had to use for his classes were full of
mistakes, so Babbage decided to build a
machine that could make exact copies of the
tables. He soon lost interest in his first
attempt, the Difference Engine. Charles
Babbage planned the Analytical Engine
instead, a machine amazingly similar to a
computer. It read programs from punched
cards, figured and stored the answers to
problems, and printed the answers on paper.
He died before he could complete it and his
son made a model from his father’s notes and
drawings. Babbage is called the Father of
• The U.S. Census Bureau held a contest to find better
ways to count and record the census. The contest
winner, Herman Hollerith came up with the Tabulating
Machine. It used punched cards to read and sort data.
The punched cards were made to match each person’s
answers to questions, and were read by the Tabulator as
they passed over tiny brushes. Each time a brush found
a hole, it completed an electric circuit and special
counting dials would record the new data for that answer.
• Punched card machines were beginning to be used by
scientist and they underwent big changes. Howard Aiken
of Harvard University started working on a generalpurpose machine similar to the Analytical Engine. The
Mark I, completed in 1944 could be programmed to do
many computing jobs and was the first automatic
calculator. It was not a true computer because it was
operated through mechanical methods instead of
electronic methods.
• John Vincent Atanasoff and his helper, Clifford Berry,
were working on the first electronic computer at Iowa
State University before the Mark I was even finished.
Atanasoff were doing complex math research that
couldn’t be done by any calculating machines of his time,
so he invented the ABC. It stood for “Atanasoff-Berry
Computer”. The ABC used vacuum tubes for counting
and storing data, which was unusual for computers at
that time. All the data fed into the ABC were coded using
binary notation, meaning any number or letter were
written in a series of zeros and ones. They stood for two
states of electricity: “on” and “off”.
• These two had met Atanoff earlier and learned about the
vacuum tubes. They also planned to build a computer at
the University of Pennsylvania Moore School of
Engineering. The U.S. Army heard about their ideas and,
since it was during WWII, they asked them to build the
computer in the hopes that it could help the soldiers
figure their gunnery tables fast. The machine was called
the Electronic Numerical Integrator And Calculator,
ENIAC for short. It was huge and could do a math
problem that would take one person 40 hours to do in 20
• There was an inconvenience about the
ENIAC: It took operators several hours to
rewire and reset its switches when
needed to be reprogrammed. John Von
Neumann outlined a way to overcome the
problem, called the stored- program
concept. He said that instructions could
be stored in the computer’s primary
memory. The computer would read the
holes in a new set of paper to change
what was held in memory. This idea
resulted in a new computer, called the
EDVAC. It was short for Electronic
Discrete Variable Automatic Computer.
• Computers had truly begun when vacuum tubes were
used for counting and storing data. There are four
generation for computers. The First Generation was
1951-1958. UNIVAC computers were invented by
Mauchly and Eckert, who had also built the ENIAC.
These computers were large, slow and produced lots of
heat. The Second Generation was 1959-1964.
Transistors began to replace vacuum tubes in
computers. They were smaller and gave off less heat.
Second generation machines had a better form of
primary memory. They led to real-time computing, so that
events could be input and processed as they happened.
• The Third Generation, 1965-1970, saw the creation of
integrated circuits. Jack S. Kilby of Texas Instruments
found a way to put several circuits onto a tiny chip. His
first integrated circuit didn’t work very well, but soon
silicon chips were being used. They were tiny and could
hold 64 circuits. The Fourth Generation is 1971- today.
Engineers are finding new ways to put even more
circuits onto single chips. These are called large-scale
integration. This makes computer much faster, smaller
and increases memory. Ted Hoff made a microprocessor,
leading to the invention of personal computers. They
were in DIY kits. Soon, they were being sold in stores. A
lot more programs were created.