Unit 2
Evolution of the computer and the
modern Computers
History of Computing
The history of Information and Communication
Technology can be divided into four main areas.
1. Pre mechanical era (before 1450)
2. Mechanical era (1450-1840)
3. Electromechanical era (1840-1940)
4. Electronic era (1940 to date)
Early calculating aids
Abacus - In 3000BC, the Chinese invented the
Abacus.
Pascaline - In 1642 Blaise Pascal developed the
pascaline which could do additions and
subtractions.
Leibnitz Calculator - in 1673 Leibnitz improved the
pascaline so that it could do multiplications and
divisions.
Difference Engine - In 1820 Charles Babbage
designed the Difference Engine.
Analytical Engine - In 1834 Charles Babbage
designed the Analytical Engine.
Electronic Age of Computing
The invention of the Electronic valve by Forrest in
1906 laid the foundation for to the modern computer
technology.
In 1944, Howard Aiken, an American mathematician,
designed the Automatic Sequence Controlled
Calculator (ASCC) which was better known as the
Mark 1. It was funded by IBM and was used in the
Harvard University and was used in the war effort.
A Navy officer called Grace Hopper was one of the
team members who worked with Howard Aiken was
the first to introduce the word “bug” for a computer
error as a real bug was stuck on a circuit board.
First Generation Computers (1940 - 1956)
ENIAC (Electronic Numerical Integrator and
Calculator) invented in 1946 is considered the first
electronic digital computer.
EDVAC (Electronic Discrete Variable Automatic
Computer) invented in 1948, is considered the
first digital computer that could store programs
(used the Von Neumann Architecture).
UNIVAC (Universal Automatic Computer) in 1956
is the first commercial and mass produced
computer.
Second Generation Computers (1956 - 1964)
The Transistor was invented by William Shockley,
Wolter Brattain and John Bardeen in 1947.
Many drawbacks of vacuum tubes were overcome
by Transistors.
Third Generation Computers (1964 - 1971)
In 1964, the Integrated Circuit was invented by
Jack Kilby and Robert Noyce separately.
With the invention of the IC, computers became
small in size, low in price and had more speed.
Small Scale Integration (SSI)
Medium Scale Integration (MSI)
Fourth Generation Computers (1971 - )
Gilbert Hyatt is regarded as the inventor of
the Microprocessor in 1968.
Computers built using these had increased
efficiency and speed, and a drop in size and
cost.
Very Large Scale Integration (VLSI)
Ultra Large Scale Integration (ULSI)
MIT built the ALTAIR 8800 in 1975.
IBM built the IBM-PC in 1981 which was the
first personal computer.
Apple built the Macintosh in 1984 as a
response to that, which revolutionized the PC
industry.
Future directions of computer technology.
The anticipation of present day scientists is to build a
computer that perform functions of an intelligent
human. In computer science this particular field is
called Artificial Intelligence. Man has the ability to
involve himself in complex activities like concentrating
on different traits of thought at the same time, and to
distinguish between different voices. Robot
technology and the construction of automatic vehicles
based on artificial intelligence, are technologies
already in place.
While the concept of the molecular computer / DNA
computers and biological computers are already in
process they will be a reality in the future. Further,
the development of a quantum computer by 2015 is
one aim of the scientists. These are considered
objectives of the fifth generation computers.
