1. Generations of computers

2. introduction
The first electronic computer was designed and built at the University of Pennsylvania based on vacuum tube technology. Vacuum tubes were used to perform logic operations and to store data.
Generations of computers has been divided into five according to the development of technologies used to fabricate the processors, memories and I/O units.

3.   A generation refers to the state of improvement in the development of a product.  This term is also used in the different advancements of computer technology.  With each new generation, the circuitry has gotten smaller and more advanced than the previous generation before it.  As a result of the miniaturization, speed, power, and memory of computers has proportionally increased.  New discoveries are constantly being developed that affect the way we live, work and play

4. Transitional period I Generation : 1945 – 55 II Generation : 1955 – 65
III Generation : 1965 – 75
IV Generation : 1975 – 89
V Generation : 1989 to present
VI Generation : Future

5. COMING UP TECHNOLOGY

6. FIRST GENERATION COMPUTERS
During the period of 1940 to 1956 first generation of computers were developed.
The first generation computers used
vacuum tubes for circuitry and magnetic
drums for memory, and were often
enormous, taking up entire rooms.
 The vacuum tube was developed by
Lee De Forest. A vacuum tube is a device generally used to amplify a signal by controlling the movement of electrons in an evacuated space.

7. Colossus was the first electronic computer of this era
Colossus  was  the first  electronic  computer  of  this  era. It's  every  aspect  
was  kept secret by British Government.

8. (Universal Automatic Computer)
UNIVAC -1951
(Universal Automatic Computer)
First fully electronic digital
computer built in the U.S.
Created at the University
of Pennsylvania
ENIAC weighed 30 tons
contained 18,000 vacuum
tubes
Cost a paltry $487,000

9. CHARACTERISTICS
First generation computers were based on vacuum tubes.
The operating systems of the first generation computers were very slow.
They were very large in size.
Production of the heat was in large amount in first generation computers.
Machine language was used for programming.
First generation computers were unreliable.
They were difficult to program and use.

10. It is the Bendix G-15 General Purpose Digital Computer, a First Generation computer introduced in 1956.

11. SECOND GENERATION OF COMPUTERS

12. The computers built in the 1950s and 1960s are considered the 2nd generation computers. These computers make use of the transistors invented by Bell Telephone laboratories and they had many of the same components as the modern-day computer. For instance, 2nd generation computers typically had a printer, some sort of tape or disk storage, operating systems, stored programs, as well as some sort of memory. These computers were also generally more reliable and were solid in design.

13. TRANSISTORS
A transistor computer is a computer which uses discrete transistors instead of  vacuum tubes. The "first generation" of electronic computers used vacuum tubes, which generated large amounts of heat, were bulky, and were unreliable. A "second generation" of computers, through the late 1950s and 1960s featured boards filled with individual transistors and . magnetic memory cores they were first developed in 1947 They. Transistors are most often used to regulate the flow of an electrical current and to switch electricity on and off.

14. Throughout the early 1960's, there were a number of commercially successful second generation computers used in business, universities, and government from companies such as Burroughs, Control Data, Honeywell, IBM, Sperry-Rand, and others. These second generation computers were also of solid state design, and contained transistors in place of vacuum tubes. They also contained all the components we associate with the modern day computer: printers, tape storage, disk storage, memory, operating systems, and stored programs. By 1965, most large business routinely processed financial information using second generation computers.
It was the stored program and programming languages that gave computers the flexibility to finally be cost effective and productive for business use. The stored program concept meant that instructions to run a computer for a specific function (known as a program) were held inside the computer's memory, and could quickly be replaced by a different set of instructions for a different function. A computer could print customer invoices and minutes later design products or calculate paychecks.

15. Main Characteristics of a second generation computer are..
Second generation computer machines were based on transistor technology.
Second generation computers were smaller as compared to the first generation computers
The computational time of  Second generation computers was reduced to microseconds from milliseconds.
Second generation computers were more reliable and less prone to hardware failure. Hence, such computers required less frequent maintenance.
Second generation computers were more portable and generated less amount of heat.
ssembly language was used to program Second generation computers. Hence, programming became more time-efficient and less cumbersome.
Manual assembly of individual components into a functional unit was still required

16. 3rd generation of computers
The 3rd Generation computers replaced transistors with “integrated circuits” or I.C. was inverted by Jack Kilby as Texas instruments in 1958.
The 3rd generation computers using integrated circuits proved to be highly reliable, relatively inexpensive, and faster. Less human labour is required at assembly stage.

17. ICL(International computer limited.) CDA(Control Data Corporation.)
Example of some main frame computers developed during this generation are-
ICL(International computer limited.)
CDA(Control Data Corporation.)

18. Fourth Generation (1971-Present)
The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the components of the computer—from the central processing unit and memory to input/output controls—on a single chip.

19. Time Period: 1975 to Today Technology: VLSI (Very Large Scale Integration) Incorporated many millions of transistors & electronic circuits on a single chip Size: Small as compared to first generation computer. Processing: Faster then first generation computer

20. In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop computers and become more advanced.
As these small computers became more powerful, they could be linked together to form networks, which also led to the development of the Internet. Fourth generation computers also saw the development of the mouse and handheld devices.

21. FIFTH GENERATION COMPUTERS
Fifth generation computing 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.

22. CHARACTERISTICS Less power consumption .
High performance, lower cost and very compact.
Computers based on artificial intelligence are available.
Portable note book computers introduced .
Memory chips up to 1 GB, hard disk drives up to 180 GB and optical disks up to 27 GB are available (still the capacity is increasing) .

24. CONCLUSION
As a result of the various improvements to the development of the computer we have seen the computer being used in all areas of life. It is a very useful tool that will continue to experience new development as time passes.
Computers are used in various areas of our life. Education, entertainment, sports, advertising, medicine, science and engineering, government, office and home are some of the application areas of the computers.