Computer

1. History Of Computer
Pre-mechanicalage
Is the age in which there were no kinds of computer systems. This was a very long time ago,
estimated to be around 3000BC. This date is very much an estimate as it is difficult to gather
evidence about what systems were in use so long ago - it could have been nearer to 500BC. Once
humans had gathered the intelligence to produce computer systems - by which we mean systems
used to commute information, rather than the technological electric devices used in the 21st
Century - they did so in order to make calculations and such easier. Two systems invented at the
end of the pre-mechanical era were the abacus and the system known as 'Napier's Bones'.
ElectromechanicalAge (1840-1940)
The discovery of ways to harness electricity was the key advance made during this period.
Knowledge and information could now be converted into electrical impulses. The beginnings of
telecommunication Voltaic Battery Telegraph Telephone and Radio Voltaic Battery Alessandro
Volta invented the voltaic pile which is considered to be the first source of stored electricity in
the 8th Century. The battery made by Volta is credited as the first electrochemical cell. It
consists of two electrodes: one made of zinc, the other of copper. The electrolyte is sulfuric acid
or abrine mixture of salt and water. The electrolyte exists in the form 2H+ and SO4 2-. The zinc,
which is higher than both copper and hydrogen in the electrochemical series ,reacts with the
negatively charged sulphate. ( SO4 ) The positively charged hydrogen bubbles start depositing
around the copper and take away some of its electrons.
Age of Electronic Computers
 ENIAC (Electronic Numerical Integrator and Calculator):
This electronic machine was designed by Dr. John W. Mauchly and Dr. J. Presper Eckert. It was
built from 18,000 vacuum tubes, and 70,000 resistors. Its power consuming capacity was 50, 00,
000 Kilowatt. It was set up on 1,800 square feet of floor space. ENIAC operated on punch cards,
which were the input/ output devices and had one multiplier, one divider/ square rooter and
twenty adders. It was a very fast machine compared to the earlier electromechanical machines. It
could add two numbers in 200 microseconds and multiplication of two numbers in 2800
microseconds.

2. John Von Neumann (1903-1957):
He was born on 28 December 1903 in Budapest, Hungary. His father, Max Neumann, was a top
banker. He studied chemistry at the University of Berlin until 1923 when he went to Zurich. He
received diploma in chemical engineering from the Technische Hochschule in Zurich in 1926
and same year obtained doctorate in mathematics from the University of Budapest on set theory.
Von Neumann designed the Electronic Discrete Variable Automatic Computer (EDVAC) with
team of J.P. Eckert and J.W. Mauchly which memory holds stored program as well as data.
This “stored memory” technique as well as “conditional control transfer,” that allowed the
computer to be stopped at any point and then resumed, allowed for greater versatility
in computer programming. The key element to the von Neumann architecture was the central
processing unit, which allowed all computer functions to be coordinated through a single source.
He was regarded as “father of stored program”.
 EDSAC (Electronic Delay Storage Automatic Computer):
Designed by Maurice Wilkesat Cambridge University mathematical laboratory in 1947. It used a
mercury delay line storage system where the access time was one millisecond. It contains 3000
vacuum tubes and operated on 30KW. Time required for addition was 1500 microseconds and
that for multiplication was 4000 microseconds.
 EDVAC (Electronic Discrete Variable Automatic Computer):
It was built at Pennsylvania University and was completed in 1950 under mastermind of J.P.
Eckert and J. Mauchly.
 UNIVAC (Universal Automatic Computer):
It was the first and most powerful computer commercially available in this generation. It was
capable of processing numeric and alphanumeric data and based on principle of stored memory
of John Von Neumann. It was used for business data processing. J.P. Eckert and J.W. Mauchly
had developed in 1961, but due to some financial problem, sold out to Remington Rand.
In 1951, the UNIVAC I (Universal Automatic Computer), built by Rand, became one of the
first commercially available computers to take advantage of these advances. Both the U.S.
Census Bureau and General Electric owned UNIVACs. One of UNIVAC‘s impressive early
achievements was predicting the winner of the 1952 presidential election, Dwight D.
Eisenhower.

3. MechanicalAge
JOHANN GUTENBERG -invented the movable metal type printing process in 1450
JOHN NAPIER -invented the “napier bones” a set of wooden rods, allowing users to
multiply and divide large numbers and find square and cube roots
WILHELM SHICKARD -invents the first mechanical calculator, it can work with six
digits, and carries digits across columns.
WILLIAM OUGHTRED -invented the slide rule.
BLAISE PASCAL -invented the mechanical calculator called “pascaline” made up of clock
and gears and levers, and could solve basic math problems
Gottfried Leibnitz -invented a machine called “stepped reckoner” that could multiply 5 digit
and 12 digit numbers yielding up to 16 digit number
JOSEPH MARIE JACQUARD -developed an automatic loom that was controlled by
punched card.
arithmometer invented by Charles Xavier de Colmar, a pin-wheel type adding machines, this
device perform the same type of computations as of Leibnitz stepped reckoner, but was more
reliable.
CHARLES BABBAGE- the father of the modern computer
difference engine the first modern computer design: a steam powered adding machine
analytical engine the mechanical calculator that took information from a punched cards to
solve and print mathematical operations.