Computer History

Brief and Elaborate History of computers | computers origin | starting phase of computer




1-A computer is a device that can receive, process and store data. They are used as tools in every part of society together with the Internet. Computers nowadays are complex; there are a lot of different components inside them, and they all serve different purposes. They all need to work together for the computer to work; knowing how a computer works makes it easier to use a computer by being able to understand how a computer will respond.

2-Mechanical Computers -the very first attempts towards this automatic computing was made by blaise
pascal .He invented a device which consisted of lots of gears and chains and used to perform repeated
additions and subtractions .This  device was called pascaline.

3-Electronic Digital Device -the best known early attempt was made in the 19th century by charles
babbage ,an english scientist and mathmatician.Babbage attempted to mechanize sequences of
calculations ,eliminating the operator and designing a machine so that it would perform all the necessary
operations in a predetermined sequence .The  machine designed by babbage used cardboard cards with
holes punched in them to introduce both instructions and the necessary data into machine.The machine
was to perform the instruction dictated by the cards automatically,not stopping an entire sequence of
instruction had been completed .The punched cards used to control the machine already had been used
to control the operation of weaving machines.Surprisingly enough,  babbage obtained some money for his
project from the english government and started constructions.Although he was severely limited by the
technology of his time and the machine was never completed.Babbage succeeded in establishing the
basic principles on which modern computers are constructed.There is even some speculation that if he
had not run short of money, he might have contructed a successful machine.Although Babbage died
without realizing his dream, he had established the fundamentals concept which were used to contruct
machines elaborate beyond even his expectations.

4-By the 1930s, punched cards were in wide use in large bussiness houses, and various types of
punched-card -handling machines were available.In 1937 Howard Aiken, at harvard, proposed to IBM that
a machine could be constructed(by using some of the parts and techniques from the punched cards
machines) which would automatically sequence the operations and calculations performed. This machine
used a combination of electromechanical devices, including many relays,The machine was in operation
for some time,generating ,many tables of mathematical function(particularly Bessel function), and was
used for trajectory calculation in world war 2.

5-Aiken.s machine was remarkable for its time,but was limited in speed by use both of relays rather than
electronic devices and of punched cards for sequencing the operations. In 1943S.P Eckert and J.W
Mauchly,of the Moore school of engineering of the University of Pennsylvania,started the ENIVAC,which
used electronic components (primarily vacuum tubes) and therefore was faster,but which also used
switches and a wired plug board to implement the programming of operations. Later Eckert and Mauchly
built EDVAC, which had its program stored in the computers's memory, not depending on external
sequencing.This was an important innovations,and a computer that stores its list of operations, or
program, internally  is called a stored-program computer.Actually the EDSAC,at the University  of
Manchester,started later but completed before EDVAC,was the first operational stored-program computer.

6-A year or so  later,John Yon Neumann, at the institute for Advanced Study(IAS) in Princeton,started the
IAS in conjunction with the Moore School og Engineering, and this machine incorporated most of the
general concepts of parallel binary stored program computer.

7-The UNIVAC 1 was the first commercially available electronic digital computer and it was designed by
Eckert and Mauchly at their own company,which was later bought by Sperry Rand.The U.S Board of the
Census bought the first UNIVAC(later univac and half of Aiken's machine were placed in the Smithsonian
Institution, which they may know be seen).IBM entered the competition with IBM 701, a large machine,in
1953 and in 1954 with the IBM 650, a much smaller machine which was very successful.The IBM 701 was
the forerunner of the 704-709-7094 series of IBM machines, the first "big winners" in the large machine

8-Quite a few vacuum tube electronic computers were available and in use by the late 1950s, but at this
time an important innovation in electronic appeared -the transistor.The replacement of large,expensive
(hot) vacuum tubes with small,inexpensive,reliable and comparatively low heat-disspating transistors led
to what is called second generations computers.The size and importance of the computer industry grew at
amazing rates, while the costs of individual computers dropped substantially.

9-By 1965 a third generation of computers was introduced.(The IBM Corporation, in introducing the 360
series,used the term third generation as a key phrase in their advertising,and it remains a catchword in
describing all machine of this era) The machines of this period began making heavy use of integrated
circuits in which many transistors and other components are fabricated and packaged together in a single
small container.The low prices and high packing densities of these circuits plus lessons learned from prior
machines led to some differences in computer system design,and these machines proliferated and
expanded the computer industry to its present multibillion-dollar size.

-Present-day computers are less easily distinguished from earlier generations.There are some striking and important differences, however The manufacture of integrated circuits has become so advanced as to incorporate hundreds of thousand of active components in volumes of a fraction of an inch,leading to what is called large-scale integration(LSI) and very large scale integration(VLSI).This has led to small size,lower cost,large memory, ultra fast computers.

12-Computer is defined as a system comprising of hardware and software designed to provide and effective tool for computation,communication,and imaging.