today computer is a life.

1. TALAL JAMSHED
BSCS
Computer Generations:
The history of computer development is divided into different
generations. These generations are differentiated from one
another on the basis of technological development due to
which every next generation of computers was more compact,
cheaper, powerful and efficient than previous one.
First Generation (1940-1956) Vacuum Tubes
First generation computers were normally based around
wired circuits containing vacuum valves and used punched
cards and paper tape as input, whereas, magnetic drums
were used as the main storage medium. Output was
displayed on printouts.
These computers were very large in their sizes and occupy
almost space of an entire room. They were very expensive to
operate and in addition to using a great deal of electricity,
generated a lot of heat, which was often the cause of
malfunctions. First generation computers relied on machine
language, the lowest-level programming language
understood by computers, to perform operations, and they
could only solve one problem at a time.

2. The UNIVAC and ENIAC computers are examples of first-generation
computing devices..1.2
Second Generation (1956-1963) Transistors
The second generation of computers replaced the inefficient
vacuum tubes with a smaller and reliable component named
as transistors. Invention of transistors in 1947, was a major
step in the history of computing. It allowed decrease in size
along with more speed and energy efficiency of the second
generation of computers as compared to previous
generation. These computers still generate a lot of heat
causing damage to it. Second-generation computers still
relied on punched cards for input and printouts for output.
These computers moved from machine language to
symbolic, or assembly, languages, which allowed
programmers to specify instructions in words. These were
also the first computers that stored their instructions in
their memory, which moved from a magnetic drum to
magnetic core technology.
Third Generation (1964-1971) Integrated Circuits
Third generation of computers used included circuits to
develop their speed and competence Keyboards and
monitors replaced punched cards and printouts. Third
generation computers can run many applications at a time
with the use of an operating system. Computers of this
generation were smaller and cheaper than their
predecessors.
Fourth Generation (1971-Present) Microprocessors
1 Webopedia, “the five generations of computers”, 2010, available online at:
http://www.webopedia.com/DidYouKnow/Hardware_Software/FiveGenerations.asp last visited 12-10-2014
2 http://trillian.randomstuff.org.uk/~stephen//history/

3. The fourth generation of computers used microprocessor
which decreased the size of these computers to such an
extent that they could now fit in the palm of the hand.
In 1971, the first microprocessor namely, Intel 4004 chip
was developed. It located all the components of the
computer like central processing unit, memory, input and
output controls on a single chip. Whereas, in 1981 first
computer for the home users was introduced by IBM.
Fourth generation computers were so much powerful that
they could be linked together to form networks, which
eventually led to the development of the Internet. Graphical
User Interface (GUIs), mouse and handheld devices were
introduced in this generation.
Fifth Generation (Present and Beyond) Artificial Intelligence
In 1981 the Japanese announced a program of research on a
fifth generation of computing
Systems (FGCS) that will integrate advances in very large
scale integration, data base systems, artificial intelligence,
and the human computer interface into a new range of
computers that are closer to people in their communication
and knowledge processing capabilities. These multiple
devices, based on artificial intelligence, are still in
development, though there are some applications, such
as voice recognition, that are being used today. The use
of parallel processing and superconductors is helping to
make artificial intelligence a reality. Quantum
computation and molecular and nanotechnology will
radically change the face of computers in years to come. The
goal of fifth-generation computing is to develop devices that
respond to natural language input and are capable of
learning and self-organization.