History and Generations of Computers
Science & Technology › IT, Telecommunications and Computers · Topic 14.4
A computer is an electronic machine that accepts data, processes it by following instructions, stores it and gives results. Early counting tools were the abacus and mechanical devices such as the machines of Pascal and Leibniz. Charles Babbage designed the Analytical Engine in 1837, and Ada Lovelace wrote what is regarded as the first program for it. Modern electronic computers are grouped into five generations: first generation machines of 1940 to 1956 used vacuum tubes, second generation of 1956 to 1963 used transistors, third generation of 1964 to 1971 used integrated circuits, fourth generation from 1971 uses microprocessors, and the fifth generation is linked to artificial intelligence, parallel processing and very large scale integration. ENIAC, completed in 1946, is often called the first general purpose electronic computer.
5 min read · UPSC Prelims · Science & Technology · IT, Telecommunications and Computers
At a Glance
- First generation Vacuum tubes, 1940-56
- Second Transistors, 1956-63
- Third Integrated circuits, 1964-71
- Fourth Microprocessors, 1971-
- Fifth AI and parallel processing
- Exam link UPSC Prelims, Science & Technology: IT, Telecommunications and Computers
Where Does It Fit?
This topic follows the account of cyber law. It goes back to the machines on which cyber space runs and traces how computers changed in size, speed and cost. Previous topic: Cyber Law in India. Next topic: Types and Components of Computer Systems.
What Are the Generations of Computers?
| Generation | Technology and features |
|---|---|
| Before electronic computers | Abacus, Napier’s bones, Pascal’s calculator (1642), Leibniz’s calculator, Jacquard’s loom cards, Babbage’s Difference Engine and Analytical Engine (1837), Hollerith’s punched card tabulator (1890) |
| First (1940-56) | Vacuum tubes. Huge, hot and expensive. Machine language. ENIAC (1946), EDVAC, UNIVAC I (1951), the first commercial computer |
| Second (1956-63) | Transistors, invented at Bell Labs in 1947. Smaller, faster, more reliable. Assembly language and early high-level languages such as FORTRAN and COBOL |
| Third (1964-71) | Integrated circuits, developed by Jack Kilby and Robert Noyce around 1958 to 1959. Operating systems, keyboards and monitors. IBM System/360 |
| Fourth (1971 onward) | Microprocessors, with the Intel 4004 in 1971. Personal computers, graphical user interfaces, networking. IBM PC in 1981 |
| Fifth (present and future) | Ultra large scale integration, parallel processing, artificial intelligence, natural language, quantum and optical ideas |
| Moore’s law | Observation by Gordon Moore in 1965 that the number of transistors on a chip doubles about every two years |
What Is the Indian Story of Computing?
- First computers: India’s first computer, a HEC-2M, was installed at the Indian Statistical Institute, Kolkata, in 1956
- TIFRAC: Tata Institute of Fundamental Research Automatic Calculator, India’s first indigenous computer, built in 1950s and commissioned in 1960
- ECIL and Electronics policy: the Electronics Corporation of India built TDC-12 and the Computer Maintenance Corporation was set up in 1975
- Software exports: Indian software industry grew from the 1980s, with the Software Technology Parks of India set up in 1991
- PARAM: C-DAC’s PARAM 8000 in 1991 was India’s first parallel supercomputer, as in Supercomputers and Their Applications
- Liberalisation: the 1984 computer policy and 1991 reforms boosted the sector
- Personal computers: spread in the 1990s, followed by the internet and mobile phones
- Digital India: the present phase of mass digital services, as in Digital India Initiative and E-Governance Programmes
What Else Should You Remember?
- Ada Lovelace: daughter of the poet Lord Byron, wrote notes in 1843 including an algorithm for the Analytical Engine
- Alan Turing: proposed the Turing machine in 1936 and the Turing test in 1950
- Von Neumann architecture: design with a stored program in memory, described in 1945, used by most computers
- John Atanasoff and Clifford Berry: built the Atanasoff-Berry Computer in 1942, an early electronic digital computer
- Colossus: British code breaking machines of 1943 to 1945
- Magnetic core memory: used in second generation machines
- Apple I and Altair: 1970s kits and machines that started the personal computer era
- Graphical interface: from Xerox PARC in the 1970s, popularised by Apple Macintosh in 1984 and Microsoft Windows
- World Wide Web: proposed in 1989, as in Internet, WWW, IP, URL, HTTP
- Smartphones: fourth generation technology in a handheld form, as in Smartphone Technology and Related Concepts
- Generations of programming languages: separate from hardware generations, covered in Computer Languages and Generations of Computers
- Caution: exact year ranges differ slightly between textbooks, so the technology matters more than dates
- Personal computer era: the Altair 8800 of 1975 and the Apple II of 1977 brought computers to homes, and IBM PC standards led to the spread of compatible machines
- Software Technology Parks of India: set up in 1991, they gave tax and infrastructure support to software exporters in cities such as Bengaluru, Hyderabad and Pune
- Mobile computing: smartphones now carry more computing power than the room-sized computers of early generations
Why Does It Matter for the Exam?
- Match generation with technology: vacuum tube, transistor, IC, microprocessor
- Firsts: ENIAC, UNIVAC, Intel 4004
- Indian machines: HEC-2M, TIFRAC, PARAM
- Current affairs link: AI chips and supercomputers
- Common errors: placing ICs in the second generation or crediting Babbage with an electronic computer
As an analytical point, each generation reduced size and cost while raising speed. India moved from importing computers to building supercomputers and exporting software, but still depends on imports for advanced chips.
Why Is This Topic Important?
- Generations Technology key
- Persons Babbage, Lovelace, Turing
- India TIFRAC, PARAM
What Came Next?
The next topic covers types and components of computer systems. Next topic: Types and Components of Computer Systems.
Key People and Terms
- Vacuum tube Glass electronic switch
- Transistor Solid state switch
- IC Integrated circuit
- Microprocessor CPU on a chip
- ENIAC Early electronic computer
- Moore’s law Doubling of chips every two years
Exam Corner
Points to Remember
- ENIAC: 1946.
- Transistor invented: 1947.
- Intel 4004: 1971.
- IBM PC: 1981.
- Analytical Engine: 1837, Babbage.
Do Not Confuse With
- Transistor and integrated circuit Single switch versus many on a chip
- ENIAC and UNIVAC First electronic general purpose versus first commercial
- Hardware and language generations Machine technology versus programming levels
Memory Hook
Tube, transistor, chip, microprocessor, then AI; ENIAC forty-six, Intel seventy-one.
Mains Angle
Questions ask to match generations with technologies. These points help.
- Evolution Size down, speed up
- India From import to export
- Next AI and quantum
A Question You May Face
An original practice question, not a past paper question.
“Trace the evolution of computers through their generations and discuss the contribution of India to computing.”
How to Answer
- Early tools Abacus to Babbage.
- Generations Tube to microprocessor.
- India TIFRAC, PARAM.
- Future AI.
GS Relevance
Frequently Asked Questions
What are the generations of computers?
Computers are grouped into five generations by their main technology. The first used vacuum tubes, the second transistors, the third integrated circuits, the fourth microprocessors and the fifth is linked with artificial intelligence and parallel processing. Each generation made computers smaller, faster, cheaper and more reliable than the earlier one.
Who is called the father of the computer?
Charles Babbage is called the father of the computer because he designed the Difference Engine and the Analytical Engine in the 1800s, the first design of a programmable general purpose computing machine. Ada Lovelace, who wrote notes with an algorithm for it, is regarded as the first computer programmer.
What was ENIAC?
ENIAC, the Electronic Numerical Integrator and Computer, was completed in 1946 at the University of Pennsylvania. It used about 18,000 vacuum tubes, filled a large room and was among the first general purpose electronic digital computers. It was used mainly for calculations of artillery firing tables.
Which was the first Indian-built computer?
The Tata Institute of Fundamental Research Automatic Calculator, TIFRAC, was India's first indigenously designed and built computer, commissioned in 1960. India's first computer, an imported HEC-2M, had been installed at the Indian Statistical Institute in Kolkata in 1956.
What is Moore's law?
Moore's law is the observation made by Gordon Moore in 1965 that the number of transistors on an integrated circuit doubles about every two years, which leads to steady growth in computing power and fall in cost. It has guided the semiconductor industry for decades, though it is slowing as chips approach physical limits.
PYQ Practice — Statement Analysis
1 Second generation computers used transistors.
Replacing vacuum tubes.
2 The Intel 4004 microprocessor was released in 1971.
Starting the fourth generation.
3 Integrated circuits were the main technology of first generation computers.
That was vacuum tubes.
4 Charles Babbage designed the Analytical Engine.
In 1837.
Past Mains Questions on This Topic
This topic comes under IT, Telecommunications and Computers. UPSC Mains questions asked on the matching syllabus topic, year-wise with marks:
Related Topics
Browse the full Science & Technology index