Five Generations of Computers: Evolution, Features & Examples

Computer Generations

Computer generation refers to the major stages of technological development in computers. Initially, the term generation was used mainly to distinguish computers based on changes in hardware technology. Today, it includes advancements in both hardware and software, which together form a complete computer system.

There are five widely recognized generations of computers. Each generation is characterized by significant changes in technology, processing capability, size, speed, reliability, and applications. The dates given below are approximate and may vary slightly across different sources.

Five Generations of Computers

S.No.	Generation	Period & Key Technology
1	First Generation	1946–1959 — Based on vacuum tubes.
2	Second Generation	1959–1965 — Based on transistors.
3	Third Generation	1965–1971 — Based on Integrated Circuits (ICs).
4	Fourth Generation	1971–1980 — Based on VLSI technology and microprocessors.
5	Fifth Generation	1980 onwards — Based on ULSI technology, advanced microprocessors, and Artificial Intelligence (AI).

In Short

• First Generation: Vacuum Tubes
• Second Generation: Transistors
• Third Generation: Integrated Circuits (ICs)
• Fourth Generation: VLSI and Microprocessors
• Fifth Generation: ULSI, Advanced Microprocessors, and AI

First Generation of Computers (1946–1959)

The First Generation of Computers began in 1946 and continued until 1959. These computers used vacuum tubes as the primary components for memory and circuitry of the CPU (Central Processing Unit).

Vacuum tubes were similar in appearance to electric bulbs. They generated a large amount of heat and were prone to frequent failures, making these computers expensive, unreliable, and difficult to maintain. As a result, they could generally be afforded only by large organizations.

During this generation, batch processing operating systems were mainly used. Punched cards, paper tape, and magnetic tape were commonly used as input and output media. Computers were programmed primarily using machine language, while some systems also used hard-wired or electrically configured control mechanisms.

Main Features of First-Generation Computers

• Vacuum tube technology
• Large and unreliable
• Supported machine language
• Very expensive
• Generated a large amount of heat
• Slow processing speed
• Used relatively slow input/output devices
• Very large in size
• Required air conditioning (A.C.)
• Non-portable
• Consumed a large amount of electricity
• Mainly used batch processing

Examples of First-Generation Computers

Some important computers of this generation were:

• ENIAC (Electronic Numerical Integrator and Computer)
• EDVAC (Electronic Discrete Variable Automatic Computer)
• UNIVAC (Universal Automatic Computer)
• IBM 701
• IBM 650

 

First Generation Computer

Key Points

First Generation = Vacuum Tubes + Machine Language + Large Size + High Heat + High Power Consumption.

Second Generation of Computers (1959–1965)

The Second Generation of Computers lasted from 1959 to 1965. This generation replaced vacuum tubes with transistors, which made computers smaller, faster, more reliable, and more energy-efficient than first-generation computers.

Transistors consumed less power and generated less heat than vacuum tubes. As a result, second-generation computers were more compact and reliable, although they were still expensive and generally required air conditioning.

During this generation, magnetic core memory was widely used as the primary memory, while magnetic tapes and magnetic disks were used for secondary storage. Programming also became easier with the introduction of assembly language and high-level programming languages such as FORTRAN and COBOL.

Batch processing and multiprogramming operating systems were used during this generation.

Main Features of Second-Generation Computers

• Used transistor technology
• More reliable than first-generation computers
• Smaller in size than first-generation computers
• Generated less heat
• Consumed less electricity
• Faster than first-generation computers
• Used magnetic core memory
• Used magnetic tape and magnetic disks for secondary storage
• Supported assembly language
• Supported high-level languages such as FORTRAN and COBOL
• Supported batch processing and multiprogramming
• Still expensive
• Generally required air conditioning

Examples of Second-Generation Computers

Some important computers of this generation were:

• IBM 1620
• IBM 7094
• CDC 1604
• CDC 3600
• UNIVAC 1108

Key Points

Second Generation = Transistors + Magnetic Core Memory + Assembly & High-Level Languages + Smaller Size + Greater Speed & Reliability.

Second Generation of Computer

Third Generation of Computers (1965–1971)

The Third Generation of Computers lasted from 1965 to 1971. This generation was marked by the use of Integrated Circuits (ICs) instead of individual transistors. A single IC could contain many transistors, resistors, capacitors, and associated electronic circuitry.

The development of the Integrated Circuit was a major breakthrough in computer technology. Jack Kilby is credited with the invention of the first practical integrated circuit. The use of ICs made computers smaller, faster, more reliable, and more efficient than second-generation computers.

During this generation, advanced operating systems supported remote processing, time-sharing, real-time processing, and multiprogramming. High-level programming languages such as FORTRAN, COBOL, PASCAL, PL/I, BASIC, and ALGOL were also widely used.

Main Features of Third-Generation Computers

• Used Integrated Circuit (IC) technology
• More reliable than previous generations
• Smaller in size
• Generated less heat
• Faster processing speed
• Required less maintenance
• Consumed less electricity
• Supported high-level programming languages
• Supported multiprogramming
• Supported time-sharing
• Supported real-time processing
• Supported remote processing
• Still relatively expensive
• Air conditioning was generally required

Programming Languages Used

Several high-level programming languages were used during this generation, including:

• FORTRAN II–IV
• COBOL
• PASCAL
• PL/I
• BASIC
• ALGOL-68

Examples of Third-Generation Computers

Some important computers of this generation were:

• IBM System/360 series
• Honeywell 6000 series
• PDP (Programmed Data Processor)
• IBM 370/168
• TDC-316

Third Generation of Computers

Key Points

Third Generation = Integrated Circuits (ICs) + Smaller Size + Faster Speed + Greater Reliability + Lower Power Consumption + High-Level Languages.

Fourth Generation of Computers (1971–1980)

The Fourth Generation of Computers lasted from 1971 to 1980. This generation was marked by the use of Very Large Scale Integration (VLSI) technology. VLSI circuits could integrate thousands of transistors and other electronic components onto a single chip, making it possible to develop powerful and compact microcomputers.

Fourth-generation computers became more powerful, smaller, faster, more reliable, and more affordable than computers of previous generations. The development of microprocessors and microcomputers played a major role in the personal computer (PC) revolution, making computers accessible to a much larger number of users.

During this generation, operating systems supported time-sharing, real-time processing, networking, and distributed processing. High-level programming languages such as C, C++, and dBASE were widely used.

Main Features of Fourth-Generation Computers

• Used VLSI technology
• Computers became smaller and more compact
• More powerful and faster
• More reliable
• Less expensive and more affordable
• Portable computers became possible
• Led to the widespread use of Personal Computers (PCs)
• Supported pipeline processing
• Required less cooling, and air conditioning was generally not necessary
• Significant development in computer networking
• Early foundations of the Internet emerged during this period
• Computers became widely available to individuals and organizations
• Supported time-sharing and real-time processing
• Supported network and distributed operating systems

Programming Languages Used

Some important programming languages used during this generation included:

• C
• C++
• dBASE
• Other high-level programming languages

Examples of Fourth-Generation Computers

Some notable computers of this generation were:

• DEC 10
• STAR 1000
• PDP-11
• CRAY-1 — Supercomputer
• CRAY X-MP — Supercomputer

Fourth Generation of Computer

Key Points

Fourth Generation = VLSI Technology + Microprocessors + Personal Computers + Smaller Size + Higher Speed + Lower Cost + Networking.

Fifth Generation of Computers (1980–Present)

The Fifth Generation of Computers began around 1980 and continues to the present day. This generation is characterized by the development of Ultra Large-Scale Integration (ULSI) technology, which enabled the integration of millions of electronic components onto a single microprocessor chip.

Fifth-generation computers are based on parallel processing, advanced microprocessors, and Artificial Intelligence (AI). AI is a branch of computer science concerned with developing systems capable of performing tasks that normally require human intelligence, such as learning, reasoning, problem-solving, decision-making, and understanding natural language.

During this generation, many powerful programming languages and technologies have been developed and widely used, including C, C++, Java, .NET technologies, Python, and others.

Applications of Artificial Intelligence

Fifth-generation computers have contributed to the development of:

• Robotics
• Neural networks
• Game playing
• Expert systems
• Natural Language Processing (NLP)
• Natural language understanding and generation
• Intelligent decision-making systems

Main Features of Fifth-Generation Computers

• ULSI technology
• Development of Artificial Intelligence
• Advancement of Natural Language Processing (NLP)
• Parallel processing
• Advancement in superconductor technology
• More user-friendly interfaces
• Support for multimedia
• Powerful and compact computers
• Computers available at more affordable prices
• Advanced networking and communication capabilities
• Greater emphasis on automation and intelligent systems

Programming Languages Used

Some commonly used programming languages and technologies include:

• C
• C++
• Java
• .NET technologies
• Python
• Other modern high-level languages

Examples of Fifth-Generation Computers

Examples of computers commonly associated with this generation include:

• Desktop Computers
• Laptops
• Notebooks
• Ultrabooks
• Chromebooks

Fifth Generation of Computers

Key Points

Fifth Generation = ULSI + Artificial Intelligence + Parallel Processing + NLP + Advanced User Interfaces + Powerful & Compact Computers.