The document discusses the five generations of computers from 1946 to present. Each generation is distinguished by the type of switching circuits used and improvements in size, speed, reliability and capabilities. The first generation used vacuum tubes, the second used transistors, the third used integrated circuits, the fourth used microprocessors, and the fifth aims to develop true artificial intelligence using parallel processing. Each generation saw improvements in performance, cost, and applicability of computers.

1. You know that the evolution of computer started from
16th century and resulted in the form that we see today.
The present day computer, however, has also
undergone rapid change during the last fifty years. This
period, during which the evolution of computer took
place, can be divided into five distinct phases known
as Generations of Computers. Each phase is
distinguished from others on the basis of the type of
switching circuits used

2.  The period of first generation was 1946 - 1954. Computers of first
generation used vacuum tubes as the basic components for memory
and circuitry for Central Processing Unit.The first electronic
computer, ENIAC (Electronic Numerical Integrator and calculator)
was developed in 1947 at the University of Pennsylvania, USA. This
machine had vacuum tubes as switching devices. Von Neumann
introduced the concept of stored program by around the same time
and the first digital computer using program, EDSAC (Electronic
Delay Storage Automatic Calculator), was announced in 1949.
 They were very large in size, consumed lot of power dnd emitted too
much of heat. They required to be housed in large air-conditioned
rooms.
During this period, computer programming was mainly done in
machine language. The user had to be both an electronics expert and
a programmer to use the computer for any task.

4.  These computers fast and could calculate data in
millisecond.
» Vacuum tubes were the only electronic component
available during those days.
» Vacuum tube technology made possible to make
electronic digital computers.
» Easily available and inexpensive.
» Color-coded for easier and faster identification of
readings.

5.  » The computers were very large in size.
» They consumed a large amount of energy.
» They heated very soon due to thousands of vacuum tubes.
» They were not very reliable.
» Air conditioning was required.
» Constant maintenance was required.
» Non-portable.
» Costly commercial production.
» Costly commercial production.
» Limited commercial use.
» Very slow speed.
» Limited programming capabilities.
» Used machine language only.
» Used magnetic drums which provide very less data storage.

6.  1. ENIAC (1946)
2. EDSAC (1949)
3. EDVAC (1950)
4. UNIVAC-1 (1951)


7. The period of second generation was 1959-1965. In second
generation of computer transistors were used. The transistors
were highly reliable and easier to handle and maintain than
the vacuum tubes. They required much less power. These
transistors replaced vacuum tubes in computers during this
period. The magnetic cores were used to construct large
random access memories. Magnetic disk storage was also
developed during this period.
Commercial applications rapidly developed during this period
and dominated computer use by mid 1960s. This period also
witnessed development of high level languages (like
FORTRAN, COBOL, ALGOL, and SNOWBOL) and
operating systems. The computers used multiprogramming
and batch processing operating system.

9.  » Smaller in size compared to the first generation of
computer.
» The second generations computers were more reliable.
» Used less energy and were not heated as much as the first
one.
» Better speed and could calculate data in microseconds.
» Used faster peripherals.
» Better portability as compared to the first generation.
» Accuracy improved.
» Used assembly language as well.

10. » Cooling system was required.
» Only used for specific purposes
» Constant maintenance was required
» Commercial production was difficult
» Costly and not versatile
» Puch cards were used for input.
Example of Second Generation of Computer:
1. Honeywell 400
2. IBM 7094
3. CDC 1604
4. CDC 3600
5. UNIVAC 1108
6. IBM 7030

11.  The period of third generation was 1965-1974.In this generation
silicon transistors replaced germanium transistors. Integrated
circuits were developed by interconnecting transistors, resistors
and capacitors grown on a single chip of silicon. Integrated
Circuit (IC) chips were used in computers. ICs were small in
size, less power consuming and less expensive than the previous
switching technology. Advances in storage technologies resulted
in creating large capacity magnetic ,disks and tapes and large
magnetic core based random access memory.
On software front, high level languages were improved. Fortran
IV and optimising Fortran compilers were developed.
Standardisation of COBOL (COBOL 68) was another major
development during this period.

13. » Smaller in size as compared to previous generations.
» More reliable as compared to previous generations.
» Used less energy as compared to previous generations.
» Produced less heat as compared to the previous two
generations of computers.
» Maintenance cost was low because hardware failure is reare.
» Better speed and could calculate data in nanoseconds.
» Totally general purpose
» Good storage
» Could be used for high-level languages.
» Less expensive and Better accuracy
» Commercial production increased.
» Used mouse and keyboard for input.

14.  » Air conditioning was required.
» Highly sophisticated technology required for the
manufacturing of IC chips.
» Tactile sensitivity is decreased
Example of Third Generation of Computer:
1. IBM 360/370
2. CDC 6600
3. Honeywell-6000 series
4. PDP(Personal Data Processor)
5. TDC-316
6. IBM-370/168

15.  The period of fourth generation was 1971-1980.The fourth
generation computers were made using very large scale integration
technology. Tens of thousands of components were packed on a
single chip, the size of a fingernail. It led to the development of
microprocessor. Magnetic core memories were replaced by
semiconductor memories. Personal computer operating systems j.
 Graphic User Interface (GUI) technology was exploited to offer
more comfort to users. PCs became more affordable and
widespread during this period
.
A significant development in software was the development of
concurrent programming languages like ADA. Another notable
development was the introduction of interactive graphic devices
and language interfaces to graphic systems .

17.  » More powerful and reliable than previous generations.
» Small in size
» Fan for heat discharging and thus to keep cold.
» Fast processing power with less power consumption
» No air conditioning required.
» Totally general purpose
» Less need of repair.
» Commercial production
» All types of High level languages can be used in this type
of computers
» Cheapest among all generations

18. 
» The latest technology is required for manufacturing of
Microprocessors.
Example of Third Generation of Computer:
1. IBM PC
2. Apple II
3. VAX 9000
4. CRAY
5. DEC 10
6. STAR 1000


19.  Very Large Scale Integration (VLSI) technology gave way to Ultra
Large Scale Integration that led to the development of
microprocessor chip with several million electronic components on
each. Powerful laptops, notebook PCs and desktops were the other
developments during this period.
The fifth generation is essentially about a new super-breed of
computers. These computers will be able to think and take decisions.
Artificial Intelligence is being built into the computer. The
revolutionary parallel processing is being used in the new breed of
computers in place of conventional Von Neumann architecture.
On the software front, effort is being directed at developing
languages to cope with su,h new generation computers. Languages
known as functional languages and object-oriented languages such
as C++ have been developed during this generation. Development of
more user-friendly operating systems like MS Windows and Lynux,
and Lynux based software products are the other developments
during this period.

21.  » These computers are much faster than other
generation computers.
» It is easier to repair these computers.
» These computers are much smaller in size than other
generation computers
» They are portable and easy to handle.
» Development of true artificial intelligence.
» Advancement in Parallel Processing.
» Advancement in Superconductor technology.

22. 
» They tend to be sophisticated and complex tools.
» hey can give more power to companies to watch what you
are doing and even allow them to infect your computer.
Example of Third Generation of Computer:
1. Desktop
2. Laptop
3. NoteBook
4. UltraBook
5. ChromeBook