Thursday, February 13, 2014

HISTORY OF COMPUTERS

In the early days of mankind, man used to count the head of cattle by putting lines on
trees. Slowly these lines changed to numbers. To do calculation on numbers he started inventing
machines.
1. Abacus
Abacus was probably the earliest of counting devices. It consists of rectangular wooden
frame with two compartments and beads sliding along the steel wires for counting.
Multiplication and divisions are done using repeated additions and subtractions. Even today in
which cross strings are fixed. Beads are inserted on to the strings. There are a number of rows of
beads.
2. Napier’s logs and bones:
John Napier, a Scottish mathematician invented logarithms. The use of logarithms
enabled him to transform multiplications and division problems of addition and subtractions. In
the beginning he called logarithms as artificial numbers. But later he named them logarithms.
Napier also invented a computing device consisting of sticks with numbers carved on
them. These sticks are called bones as they were made of bones. These bones helped a lot in
multiplication involving large numbers.
3. Slide rule
As the name indicates, the slide rule has one scale sliding within the other. Suppose you
want to add two numbers 3 and 5, set 3 on the fixed scale and slide the moving scale. So that its
“0’ coincides with”5” of sliding scale. This is the sum of 3 and 5. The process of reading could
be quick if you are trained in the use of slide rule.
4. Calculating machines and Pascal’s calculator:
A French mathematician, Blaise Pascal invented a machine based on gear wheels. He was
the son of tax collector who had to do lot of calculations as part of his job. Blaise Pascal wanted
to make his job easier by inventing a calculator. You might be familiar with gear wheels in use in
your bicycle which meshes with a driving chain. He used similar gear wheels with ten teeth for
each digit position. He fixed them together so that one wheel drives the other. When the wheel
corresponding to units position rotated by ten teeth, it drove the wheel corresponding to the next
higher position by one tooth. Thus one could make calculations. Pascal provided dials, which
indicated numbers stored on each wheel. He also used suitable “dialing system” to operate the
gear wheels. Other people also made a number of such calculators. Computer scientists honored Pascal by naming a programming language Pascal after
him.
5. Babbage difference and analytical engines.
Babbage, a British National and the son of a wealthy banker wanted to correct the errors
in the logarithm tables being used during his time. In 1822, he made a machine which calculated
the successive difference of expressions (X2 + ax + b is an example of an expression) and
prepared table which helped him in his calculations. The royal Astronomical society awarded a
gold medal to him for his invention and granted a large sum of money to carry out further work.
He wanted to make an accurate calculating machine called “Babbage’s Analytical Engine”. The
analytical Engine was supposed to be very accurate. So it needed lot of parts made with
precision. Babbage could not make such parts. He conceived that his machine would use input
devices, would have a processing part called “mill” where you can perform calculations, would
also incorporate
It consists of rectangular frame in which cross strings are fixed. Beads are inserted on to
the strings. There are a number of rows of beads .Since he was about 100 years ahead in his
ideas, he could not get parts needed for his machine. This is because there were no tools to make
such precision parts. He did lot of work related to making precision parts and spend all the grants
(and lot of his money too) but failed in his attempt to make a machine. He ultimately died as a
frustrated man.
6. Lady Ada Lovelace
Lovelace is the daughter of the famous English poet Lord Byron. She was a
mathematician. She studied the works of Babbage and wrote about them. From her account only,
we can see the close resemblance of the modern day computers and Babbage’s work. Lady Ada
Lovelace’s contributions are very important. Since she predicted that computers can be
programmed, a language, Ada used widely in America’s Department of Defence Computers was
named after her.
7. Herman Hollerith’s Machine
Governments all over the world collect details about the number of people living in their
countries. This information helps the Government in planning for the future, Sometimes you find
enumerators (people taking such details) coming to your house with forms to collect such details.
This operation is called “census” which is normally done once in 10 years.
In the United States a census was carried out in 1880 and the U S Government was
processing the census data. Even as this was going on, the next census was due in 1890. To
process the census of 1890 fast, the Government announced a competition.
Dr. Herman Hollerith Produced cards out of special paper pulp, designed punching
machines to punch holes in the card to count census figures and invented sorting machines to
read such punched card and collect data. He could complete the job within three years, achieving
a speedup of about three times.
8. ABC Computer:
In 1937, Dr. John Atanstoff with the help of his assistant Berry designed the Atanstoff
Berry Computer (ABC). The machine laid the foundation for the development of electronic
digital computer.
9. ENIAC- Electronic Numerical Integrator and Calculator
In 1947 john Mauchly and Eckart completed the first large scale Electronic Digital
Computer, ENIAC. In this computer, each time a program was changed, the wiring had to be
completely rearranged. It weighed 30 tons, contained 18,000 vacuum tubes and occupied a
space of 30 50 feet.
10. EDSAC-Electronic Delay Storage Automatic Calculator:
Maurice V.Wilkes of Cambridge University completed EDSAC in 1949. EDSAC was the
first computer to operate on the stored program concept.
11. UNIVAC-I – Universal Automatic Computers:
In 1947, after ENIAC became operational Mauchly and Eckart formed their own
Company- The Eckart-Mauchly Computer Corporation”. Immediately after this they started the
design of UNIVAC-I. This was purchased by US bureau of Census. UNIVAC was the first
computer dedicated to business applications.

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