Generation of computer:-

                Generation in computer terminology is a change in technology a computer is/was being used. Initially,the generation term was used to distinguish between varying hardware technologies. Nowadays, generation includes both hardware and software, which together make up an entire computer system.

        The growth that took place can be classified into five different phases of computers. These phases are known as generation of computer.

     There are five computer generations known till date. Each generation has been discussed in detail along with their time period and characteristics. In the following table, approximate dates against each generation have been mentioned, which are normally accepted.

Following are the main five generations of computers.

fig:-Generation of Computers

Generation and Description about Generation:-

S.No	Generation & Description
1	First Generation:- v The period of first generation: 1940-1950. v  Vacuum tube based.
2	Second Generation:- v The period of second generation: 1950-1960. v Transistor based.
3	Third Generation:- v The period of third generation: 1960-1970. v Integrated Circuit based.
4	Fourth Generation:- v The period of fourth generation: 1970-1980. v VLSI microprocessor based.
5	Fifth Generation:- v The period of fifth generation: 1980-onwards. v  ULSI microprocessor based.

There are five generations of computer till date.

1. First Generation Computer(1940-1950)-

Vacuum tubes:-

Ø These early computer used Vacuum tubes as circuitry and magnetic drums for memory.

Ø These tubes were used in the arithmetic and logical operations.

Ø Vacuum tube is an electronic device that permitted the processing of digital signals at a faster speed.

Ø These generation computer relied on ‘machine language’ and machine language is known as binary language.

Ø In this input was based on punched cards and paper tube.

Ø Output came out on print-outs.

Ø In this, the two machine of this era were the UNIVAC and ENIAC machines.

v Features (Advantages) of First Generation Computer:-

Ø They were capable of making arithmetic and logical operations.

Ø Use vacuum tubes.

Ø Big and clumsy (Big Size).

Ø High electricity consumption.

Ø They used the electronic values in place of the key punch machines or the unit record machines.

Ø Programing In Mechanical language.(Binary language or machine language)

Ø Computers were not reliable.

Ø In this may be, it is use 1800 vacuum, 70000 Register, 10,000 capacitor, 60,000 switched.

Ø  The weight of this computer is 30 tones etc.

v Disadvantage of First Generation Computer:-

Ø They were too big in size, very slow, low level of accuracy and reliability.

Ø Unreliable

Ø Air conditioning was required because they consumed lot of electricity, generated a lot of heat and break down frequently.

Ø They were non portable.

Ø They were large in size, slow in processing, and had less storage capacity.

Ø They use machine level language for programming.

Ø Limited commercial use etc.

v Example:- ENIAC,EDVAC, EDSAC,UNIVAC etc.

2.    Second Generation Computer(1950-1960)-Transistors:-

 Ø This Generation Computer used a solid-side device called Transistor in the place of vacuum tube (replacement of vacuum tube used by transistors).i.e

                   These computers used transistors in place of vacuum tubes as their basic element all computational and logical works.

Ø Transistors were very convenient when compared to vacuum tube.

Ø The language evolved from cryptic binary language to symbolic (“Assembly”) languages. This meant programmer could create instruction in words.

Ø About the same time high level programming languages were being developed (early versions of COBOL and FORTRAN)

Ø Transistor-driven machines were the first computers to store instructions into their memories – moving from magnetic drum to magnetic core ‘technology’

Ø The early versions of these machines were developed for the atomic energy industry.

v Features (Advantages) of Second Generation Computer:-

Ø Transistor was used.

Ø Core Memory was developed.

Ø Faster than first generation computer.

Ø Programming was in machine language and assembly language.

Ø Magnetic tapes and discus were used.

Ø Weight was also much less.( compare to first generation computer)

Ø These computers were more reliable.

Ø They have high processing speed.

Ø Less power was required in this computer. i.e.

They required very small space, were fast and reliable and dependable.

Ø Consume less electricity.

Ø Small size compare to first generation computer.

Ø Less heat generated.

Ø Faster computing capacity.

Ø They used better peripheral devices like card readers and printer etc.

Ø They input and output device were faster.

v Disadvantage of Second Generation Computer:-

Ø They did not have any operating system and used assembly languages.

Ø Air-conditioning required.

Ø They lacked in intelligence and decision making and needed constant upkeep and maintenance.

Ø Frequent maintenance required.

Ø Commercial production was difficult and costly etc.

v Example:- IBM-700, IBM-1401, IBM-1602, IBM-7094, ATLAS LEO Mark-II,CDC-1604, UNIVAC-1108 etc.

3.    Third Generation Computer(1960-1970)-Integrated Circuits:-

Ø Around 1960, it becomes possible to pack a number of transistors (and other electronic component on a single crystal) in thin chips.

Ø These chips which were called the Integrated Circuits(IC’s).

Ø They had a number of interconnected transistors on a single chip i.e. (transistors were now being miniaturised and put on silicon chips(called semiconductors).

v   Features (Advantages) of Third Generation Computer:-

Ø It built with thousands of transistor which were very cheap.

Ø They used faster better device for storage, called auxiliary backing or secondary storage.

Ø Integrated circuits developed.

Ø They used operating system for better resource management and used the concept of time sharing and multiple programming.

Ø They created lot of problems to the manufactures at their initial stages.

Ø Power consumption was low.

Ø They lacked thinking power and decision making capability.

Ø Weight was also reduced.

Ø They were very small in size.

Ø Transistors were replaced by IC’s.

Ø Their cost was much less.

Ø They are more reliable.

Ø Maintenance cost is low because hardware failures are rare.

Ø They use high level language for programming.

Ø They could not provide any insight into their internal working.

v Disadvantage of Third Generation Computer:-

Ø Air conditioning required in many cases.

Ø High sophisticated technology required for the manufacture of IC’s etc.

v Example:- ICE-2903, CDC-1700, PDP-1145, IBM-360/370, CDC-6600 etc.

4.  Fourth Generation Computer(1970-1980)- VLSI Microprocessors:-

Ø Around the year 1970, it become possible to have IC’s with thousands of interconnected transistors this was called the ‘Microprocessor’. This chip was called “Very Large Scale Integrated (VLSI)”  or “Microprocessor”.

Ø A microprocessor is a single chip which itself can perform the controlling arithmetic and logical functions of a computer that too at a fast speed.

Ø The chip-maker developed the Intel 4004 chip in 1971, which positioned all computer components (CPU, memory, input/output controls) onto a single chip.

Ø The Intel chip housed thousands of integrated circuits.

v   Features (Advantages) of Fourth Generation Computer:-

Ø They were very compact faster and reliable as they used very large scale integrated circuits.

Ø They were capable of facilitating the interactive on line remote programming by which one sitting at the distance place can get his programs executed by centrally located computer.

Ø LSI (Large scale Integrated) and VLSI (Very Large scale Integrated) Technology used.

Ø Development of portable computer.

Ø Size of computer was so small.(very small in size and cost of operation was very less)

Ø Low cast and affordable.

Ø Memory capacity was also increased.

Ø Computer started in use for Data communication.

Ø Different type of memory with very high accessing speed and storage capacity.

Ø Used in virtual multimedia simulation.

Ø Very reliable.

Ø High generated negligible.

Ø Totally General purposed etc.

v Disadvantage of Fourth Generation Computer:-

Ø High sophisticated technology required for the manufacture of LSI chips.

Ø They are less powerful and had less speed than the main frame computers.

Ø They lacked thinking power and decision making ability.

Ø They had less storage capacity and needed further improvement.

v Example:- IBM PC, Apple II, ICE-2900, Pentium , Intel 4004 etc.

5.  Fifth Generation Computer(1980-Onwords)- ULSI microprocessor based(or Artificial Intelligence):-

Ø In this generation, researches are focused on development “thinking computers”.

Ø The fifth Generation based on “Artificial Intelligence”are still under development.

Ø These computers are likely to be used in the future.

Ø “AI(Artificial Intelligence) is the techniques with which machine can be made to think and take decision like man.”

v Features (Advantages) of Fifth Generation Computer:-

Ø They have thinking power and decision making capability and thereby they will be able to aid the executives in the management.

Ø They faster and very cheap and have the highest possible storage capacity.

Ø They are oriented towards integrated data base development to provide decision models.

Ø Used in parallel Processing.

Ø Used super conductors.

Ø Used speech recognition.

Ø Used intelligent robots.

Ø Used AI.

Ø Translating foreign languags.

Ø Learn from its own experiences.

v Disadvantage of Fifth Generation Computer:-

Ø They need very low level languages.

Ø They may replace the human force and cause grievous unemployment problems.

Ø They may make the human brain dull and doomed.

v Example:- IBM notebooks, Pentium PCs,  SUN Workstations, IBM SP/2, SGI Origin 2000,PARAM supercomputers etc.

Tarun Sir

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