Generations of Computers amd | Five generation of computers

Generation Of Computers

Computers were developed in five distinct phases known as computer generations. There are totally Five computer Generations known till today.

1. First Generation computers(1945-55)
2. Second Generation Computers(1956-64)
3. Third Generation Computers(1965-74)
4. Fourth Generation Computers(1975 - onwards)

First Generation computers(1945-55)

First Generation Computers used thermionic tubes(Vacuum tubes) as basic elements.Programs and their data were located in the same memory, as they are today.First generation ASSEMBLY language was used to prepare programs and was translated into machine language for execution.Basic arithmetic operations were performed in a few milliseconds. Input/Output functions were performed by devices similar to typewriters.Magnetic core memories and magnetic tape storage devices were also developed .
Examble of first generation computers :

ENIAC,EDVAC,EDSAC,MARK 1 and UNIVAC

-(Show those in details)

Advantages of First generation computers

1. VACUUM TUBE were the only electronic components available during those days.
2. VACUUM technology made possible the advent of electronic digital computers.
3. These computers were the faster calculating devices of their time. They could perform computation in MILLISECONDS

Disadvantages of first generation computers

1. Too bulk in size and hence very large space required
2. Unreliable
3. Thousands of Vaccum tubes that were used emitted large amount of heat and burnt out frequently
4. Slow operating speed and restricted computing capacity
5. High power consumption and short life span
6. Air conditioining required
7. Frequent hardware failure
8. Constant Maintenance required
9. Non portable
10. Manual integration of individual components into functioning unit required
11. Commercial production was difficult and costly.
12. Limited programing capabilities and hence, limited commercial use

Second Generation Computers(1956-64)

The second Generation began with the advent of TRANSISTORISED CIRCUITRY,Magnetic core and Magnetic drum storage devices were widely used in second generation.The high reliability and large storage availability lead to the development of the high-level languages like FORTAN,COBOL,ALGOL etc., making the preparation of application programs much easier . System programs called compiler were developed to translate the high level language programs into corresponding Executable machine language form.
Separate I/O processors were developed that could operate parallel to the Central processor that executed programs, thus improving overall performance.IBM became the major computer manufacture during this time
Examples of second generation computers:

• IBM 1620 (Scientific)
• IBM 1401 (Business)
• IBM 7094 (Scientific and Business)
• CDC 1604 (Scientific)
• CDC 3600 (Scientific)
• RAC 501 (Business)
• UNIVAC 1108 (Scientific and Business)

Advantages of Second Generation Computers

1. Smaller in size as compared to First Generation Computers
2. More reliable
3. Lower power consumption and hence reduced running cost
4. Higher operating speed.Computational time reduced from Milliseconds to Microseconds
5. Less Prone to hardware failure
6. Better portability
7. Reduced manufacturing cost and hence wider commercial use

Disadvantages of Second Generation Computers

1. Air conditioning was required
2. Frequent maintenance was required
3. Manual integration of individual components into functioning units was required
4. Commercial production was difficult and costly

Third Generation Computers(1965-74)

The ability to fabricate many transistors on a chip called IC technology, Enabled low-cost and faster processors and memory elements to be built. IC memories began to replace Magnetic core memories.These technological developments marked the beginning of the third generation. Other developments includes the introduction of microprogramming, parallelism and pipelinig.
Cache and virtual memories were developed,operating system allow to efficient sharing computer system.
Examples of Third Generation computers:

• IBM 360 series
• IBM 370/168
• ICL 1900 series
• ICL 2900
• HONEY WELL MODEL 316
• HONEY WELL 6000 series

The development of Large Scale Integration(LSI) and Very Large Scale Integration(VLSI) and microprocessor chips help to manufacturing of minicomputers,mainframe computers.

Advantages of Third Generation computers

1. Smaller in size compared to previous generation computers
2. More reliable than second-generation computers
3. Lower heat generated
4. Computational time reduced from microseconds to nanosecond
5. Maintenance cost is low because hardware failure are rare
6. Easily portable
7. Totally general purpose Widely used for various commercial application all over the world
8. Less power required than previous generation computers
9. Manual integration was not required
10. Commercial production was easier and cheaper

1. Air conditioning required in many cases
2. Higher sophisticated technology required for the manufacturing of IC chips

Fourth Generation Computers(1975 - onwards)

Very Large Scale Integration (VLSI) technology had evolved to the point where the computer processor could be fabricated on a single chip. This came to be known as MICROPROCESSOR. The development of the microprocessor made it possible to place complete Central Processing Unit(CPU) on a single chip. those computers are called microcomputers.
Computers organization concept such as Parallelism,piplining and cache and virtual memories help to produce high performance computing systems of today as the fourth generation.Interconnection of Desktop computers by using Local Area Network(LAN)

Advantages of Fourth Generation Computers

1. Smallest in size because of high density of components in a single chip
2. More reliable
3. Heat generated is negligible
4. Air-Conditioning was not required in many cases
5. Much faster in computation
6. Hardware failure is negligible and hence minimal maintenance cost<./li>
7. Easily Portable because of their small size
8. Totally general purpose
9. Minimal labour cost involve at assembly stage
10. Cheapest among all generations

Disadvantages of Fourth Generation computers

1. Highly sophisticated technology required for the manufacturing of VLSI chips

Fifth Generation Computers(Yet to Come)

The fifth Generation computers are under development .Scientists are now at work on the fifth generation computers.

Characteristics of Fifth Generation computers

• Parallel processing instead of serial processing and will be able to do multiple tasks simultaneously
• Perform knowledge processing instead of data processing
• It will interact with humans in natural language instead of computer language
• It will interact with humans in natural language instead of computer language
• Super speed
• Behave like an expert and show Artificial intelligence