R ORIGIN AND EVOLUTION
The word "computer" is derived from the word
compute. Computer literally means a machine
which does calculation or computation. But its
literal meaning is insufficient to describe the
actual meaning of computer. Basically, the
computer is a device that stores, processes and
retrieves (extracts) information in a very short
time. Today, it is used in every sphere of human
About 5000 years ago Greek invented a calculating
machine called Abacus. This was regarded as the first
digital computer. Later, in 1614; the Logarithm table
was invented by John Napier. In 1642, a French
scientist, Blade Pascal invented a device for additions.
This was improved by Godfrey Libnittis, who was the
inventor of the multiplication device in 1673.
Both these devices were not foolproof at there
performance. Thus later in 1820, another scientist named Mr.
Charles Thomas, developed prototype of today's calculator
with improved facilities. In 1822, Charles Babage, a British
scientist, who was the professor of mathematics, designed a
"difference engine" for the Royal Society, which was meant
for addition and multiplication. Since, its performance could
not overcome the Charles Babage expectations, he
developed a more efficient machine which also had the
facilities to do addition and multiplication, called "analytical
engine". Charles Babage is considered as the "father of
modern computer" for his harsh effort and work which lead
to the evolution of computers. By 1920, machines that
worked on electricity came into being and it greatly
increased the speed and efficiency.
The 1970s could be called as the era of the minicomputer.
These were progressively smaller and cheaper machines than
the standard mainframe era computers. The standard
mainframe of the 1970s shrunk from a room full of cabinets
and tape drives to a decorative office machine perhaps 3 to 5