Generations of Computers Notes for SSC Exams

Generations of computers is one of the most repeated topics in SSC Computer Knowledge. Almost every year, a question is asked on the technology of a generation, its examples or its inventor. These generations of computers notes for SSC give you the full table, the key facts and practice questions in one place. After this topic, read the Types of Computers Notes and Computer Memory Notes notes, and also revise the Computer Knowledge Notes for SSC.

What Is a Generation of Computers?

A generation of computers shows a major change in the technology used to build computers. With every new generation, computers became smaller, faster, cheaper and more reliable.

• There are five generations of computers.
• Each generation is defined by the main electronic component: vacuum tube, transistor, integrated circuit, microprocessor and artificial intelligence.
• The dates given in different books may differ by a few years, so remember the technology first and the dates next.

The Five Generations at a Glance

Key Features of Each Generation

• First generation: very large, used a lot of electricity, produced heat and failed often. Input was by punched cards.
• Second generation: transistors made computers smaller, faster and more reliable than vacuum tubes. Magnetic core memory was used.
• Third generation: the integrated circuit (IC) was invented by Jack Kilby in 1958. Keyboards, monitors and operating systems came into use.
• Fourth generation: the microprocessor (Intel 4004, 1971) put the whole CPU on a single chip. Personal computers, GUI and networks started.
• Fifth generation: based on artificial intelligence, parallel processing, voice recognition and robotics.

Pioneers and Early Machines to Remember

Detailed Study of Each Generation

First generation (1940 to 1956): vacuum tube computers. A vacuum tube is a glass tube that controls the flow of electric current. These computers filled entire rooms, used a huge amount of electricity and produced so much heat that they needed air conditioning. They worked only in machine language and used punched cards and paper tape for input and output. They could solve only one problem at a time (single tasking). Famous machines are ENIAC (1946), EDVAC, EDSAC, UNIVAC I (the first commercial computer, 1951) and IBM 701. Main drawbacks were large size, high cost, frequent failures and no operating system.

Second generation (1956 to 1963): transistor computers. The transistor was invented at Bell Labs in 1947 by John Bardeen, Walter Brattain and William Shockley. A transistor is smaller, cheaper, faster and more reliable than a vacuum tube and produces less heat. Magnetic core memory was used as the main memory and magnetic tapes and disks were used for storage. Assembly language replaced machine language, and high-level languages such as FORTRAN (1957) and COBOL (1959) were developed. Examples are IBM 1401, IBM 7090 and CDC 1604. These computers were used for business work such as payroll and for scientific work.

Third generation (1964 to 1971): integrated circuit computers. Many transistors were placed on a single silicon chip called an integrated circuit (IC). Jack Kilby of Texas Instruments made the first IC in 1958, and Robert Noyce of Fairchild made a practical silicon IC soon after. Computers became smaller, faster and cheaper, and they used much less power. Keyboards and monitors replaced punched cards, and operating systems allowed multiprogramming, which means many programs could run at the same time. High-level languages like BASIC, Pascal and COBOL were used widely. The IBM System/360 (1964) and the PDP-8 minicomputer are the best-known examples.

Fourth generation (1971 to present): microprocessor computers. VLSI (Very Large Scale Integration) put thousands and then millions of transistors on a single chip. In 1971 Intel launched the 4004 microprocessor, the first complete CPU on one chip. This led to personal computers (PCs): Altair 8800 (1975), Apple I and II (1976-77) and IBM PC (1981). Graphical user interface (GUI), the mouse, networking, the internet, laptops and smartphones belong to this generation. Languages such as C, C++, Java and Python are used. Semiconductor memory such as RAM and ROM replaced core memory.

Fifth generation (present and future): artificial intelligence. These computers use ULSI (Ultra Large Scale Integration), parallel processing, artificial intelligence, voice and face recognition, robotics, natural language processing and quantum computing ideas. Japan started its Fifth Generation Computer Systems project in 1982. Modern examples are AI assistants, expert systems, self-driving vehicle systems and supercomputers.

Comparison of the Five Generations

Early Calculating Devices and History

Important note: Charles Babbage never completed the Analytical Engine in his lifetime, but his design had all the parts of a modern computer: input, memory, processing unit and output. Ada Lovelace wrote notes for it that are called the first computer program.

Computers in India

• The first computer in India was installed at the Indian Statistical Institute, Kolkata, in 1953 (HEC-2M).
• TIFRAC (1956) was the first computer designed and built in India, at the Tata Institute of Fundamental Research, Mumbai.
• The first indigenously designed digital computer was ISIJU-1 (1966).
• C-DAC (Centre for Development of Advanced Computing) was set up in 1988 in Pune. It built the PARAM series of supercomputers; PARAM 8000 (1991) was the first, and PARAM Siddhi-AI (2020) is a recent one.
• Dr. Vijay Bhatkar is called the architect of India's supercomputing programme.
• The National Supercomputing Mission (2015) aims to connect supercomputers across the country.

Exam Strategy for This Topic

SSC usually frames the questions in four ways: the technology of a generation, the example of a generation, the inventor and the language. Make a one-page chart of the table above and revise it daily. Do not rely on exact years, because books show slightly different dates; instead remember the order of technology: vacuum tube, transistor, IC, microprocessor and AI. For the history, remember the pairs "Babbage with the Analytical Engine", "Pascal with the Pascaline", "Aiken with Mark I", "Mauchly and Eckert with ENIAC" and "Kilby with the IC".

Important Questions Explained

Question 1: Which technology was used in first generation computers?
Answer: Vacuum tubes.

Question 2: Who invented the integrated circuit?
Answer: Jack Kilby, at Texas Instruments, in 1958. It gave rise to the third generation.

Question 3: In which generation was the microprocessor introduced?
Answer: The fourth generation. The Intel 4004 was the first microprocessor (1971).

Question 4: What type of language was used in the first generation?
Answer: Machine language, which has only 0s and 1s.

Question 5: Which generation of computers is based on artificial intelligence?
Answer: The fifth generation.

Question 6: Who is known as the first computer programmer?
Answer: Ada Lovelace, who wrote a program for Babbage's Analytical Engine.

Quick Tips to Remember

• Learn the technology chain: vacuum tube, transistor, IC, microprocessor, AI.
• Remember Babbage as the father of the computer and Lovelace as the first programmer.
• Link ENIAC with the first generation and IBM 360 with the third generation.
• Do not mix up the transistor (second generation) with the IC (third generation).
• Remember that the dates may differ across books, so do not choose an option only because of the year.

Common Mistakes to Avoid

• Writing ICs for the second generation and transistors for the third.
• Confusing ENIAC (first electronic computer) with UNIVAC (first commercial computer).
• Mixing Babbage (father of computer) with Pascal (first mechanical calculator).
• Writing the wrong language for the generation.
• Forgetting that the fourth generation continues till today.

Quick Revision Points

• 1st: vacuum tube. 2nd: transistor. 3rd: IC. 4th: microprocessor. 5th: AI.
• Father of computer: Charles Babbage.
• First programmer: Ada Lovelace.
• IC inventor: Jack Kilby.
• ENIAC was the first general-purpose electronic computer.

Practice Questions With Answers

1. Transistors were used in which generation?
   Answer: Second generation (Replaced vacuum tubes).
2. What is the full form of ENIAC?
   Answer: Electronic Numerical Integrator and Computer (Built in 1946).
3. Who is called the father of the computer?
   Answer: Charles Babbage (Analytical Engine).
4. Which component is used in the third generation?
   Answer: Integrated circuit (IC) (Invented by Jack Kilby).
5. Which language did the second generation use?
   Answer: Assembly language (And early high-level languages).
6. Which generation used VLSI and microprocessors?
   Answer: Fourth generation (Intel 4004 in 1971).
7. Who invented the Pascaline?
   Answer: Blaise Pascal (A mechanical calculator).
8. Which was India's first supercomputer?
   Answer: PARAM 8000 (C-DAC, 1991).
9. Which computer is called the first commercial computer?
   Answer: UNIVAC (First generation).
10. Which device is the earliest known calculating tool?
    Answer: Abacus (Used for counting).

More Practice Questions With Answers

1. Which generation of computers used magnetic core memory?
   Answer: Second generation (Transistor era).
2. Who designed the Analytical Engine?
   Answer: Charles Babbage (1837).
3. Who built Mark I?
   Answer: Howard Aiken (1944).
4. Which computer first used the stored-program concept?
   Answer: EDVAC (Von Neumann idea).
5. Which was the first commercial computer?
   Answer: UNIVAC I (1951).
6. What does VLSI stand for?
   Answer: Very Large Scale Integration (Fourth generation).
7. Which company launched the Intel 4004?
   Answer: Intel (1971).
8. Where was TIFRAC built?
   Answer: Tata Institute of Fundamental Research (1956).
9. Which institute set up the PARAM supercomputers?
   Answer: C-DAC (Pune).
10. Who made the first practical silicon IC along with Kilby's work?
    Answer: Robert Noyce (Fairchild).
11. Which language was developed in 1957 for science?
    Answer: FORTRAN (Second generation).
12. Which machine used punched cards for the US census?
    Answer: Hollerith tabulating machine (1890).

How to Practise This Chapter

1. Read the tables once and learn the key facts by heart.
2. Revise the quick revision points the next day.
3. Attempt the practice questions above without looking at the answers.
4. Solve a full SSC CGL Tier 1 mini mock to test your general awareness.
5. Check the previous year papers to see how SSC asks computer questions.

Related Notes and Practice Papers

• Types of Computers Notes
• Computer Memory Notes
• Operating System Notes
• Computer Knowledge Notes for SSC
• SSC CGL Tier 1 Mini Mock

Explore More SSC Subjects

SSC exams test many subjects, so connect this topic with the related subjects below:

• General Science Notes
• General Awareness Notes
• Quantitative Aptitude Notes
• Reasoning Notes
• Electrical Engineering (SSC JE) Notes
• All SSC subjects and notes

Frequently Asked Questions

How many generations of computers are there?

There are five generations of computers: first to fifth.

What is the technology of the first generation?

The first generation used vacuum tubes.

Which generation used transistors?

The second generation used transistors.

Which generation used integrated circuits?

The third generation used integrated circuits (ICs).

Which generation is called the microprocessor generation?

The fourth generation, from 1971 onwards.

What is the fifth generation based on?

It is based on artificial intelligence and advanced technologies such as parallel processing and robotics.

Who is the father of the computer?

Charles Babbage is called the father of the computer.

Who invented the integrated circuit?

Jack Kilby invented the IC in 1958.

How many questions come from this topic in SSC exams?

One or two questions usually come from the generations and history of computers in the Computer Knowledge part.

Which computer was designed and built first in India?

TIFRAC, built at the Tata Institute of Fundamental Research in 1956, was the first computer designed and built in India.

Who invented the transistor?

John Bardeen, Walter Brattain and William Shockley invented the transistor at Bell Labs in 1947.

Which was the first microprocessor?

The Intel 4004, launched in 1971, was the first microprocessor.