classification of computers by generation

Classification of Computers by Generation

Classification of computers by generation is a process of arranging computers based on the period of invention. When classifying a computer system, certain characteristics are considered.

Classification of computers by generation is a process of arranging computers based on the period of invention.

When classifying a computer system, certain characteristics are considered. In this tutorial, we shall discuss the classification of computers by generation.

Classification of computer definition

Classification of computer is a process of organizing or arranging the computer system based on vital features.

These features can be physical size, processing ability, or mode of operation.

What is the classification of computers?

A typical computer system can be classified into four (4) different categories, namely;

Classification of Computers by Generation

After the invention of the first computer in 1945 which filled the entire room, subsequent computers showed improved capabilities. These improved capabilities are captured in the following features:

classification of computers by generation - summary
  • Higher processing power and computation strength
  • Reduced size and power consumption
  • Lower cost of production, acquisition, and maintenance
  • Better and improved programming languages

The classification of computers by generation captured the above features per generation. This shows the chronological improvement of the computer system as technology advanced. For a comprehensive article visit the post: different generations of computers.

First-generation computers –

These computers were developed between 1945 and 1956. They are based on vacuum tubes and have the following characteristics.

Vacuum tubesUsed for circuitry
Magnetic drumsUsed for memory and storage
SizeVery large
Power consumptionConsume a lot of power and generates a lot of heat
CostVery expensive to buy and maintain
SpeedVery slow (computation time in milliseconds)
Programming languageMachine language
Input/outputPunched cards/ printouts

Second-generation computers –

The second-generation computers were developed between 1956 and 1963 with transistors replacing vacuum tubes. Some of the characteristics include:

TransistorsUsed for circuitry
Magnetic core technologyUsed stored program concept (instructions stored in memory), magnetic tape for mass storage
Power consumptionConsume less power and generates less heat than 1st generation
CostLess expensive than first-generation
SpeedSlow (computation time in microseconds)
Programming languageAssembly language
Input/outputPunched cards/ printouts
ExamplesIBM 1401, PDP-1, UNIVAC 1107

Third-generation computers –

Third-generation computers were developed between 1964 and 1971 with integrated circuits. Other notable characteristics are.

Integrated circuitsUsed for circuitry
Hardware/ softwareThe advent of operating systems to interface between hardware/ software
SizeSmall (magnetic tape for storage)
Power consumptionLess power and less heat
CostCheaper and available to the public
Speedhigh (computation time in nanoseconds)
Programming languageHigh-level language
Input/outputkeyboards/ monitors
ExamplesIBM 360s, PDP-11, Honeywell 6000s

Fourth-generation computers –

This generation took place around 1971. It marked the advent of microprocessors in place of integrated circuits, and it is still in use today. Other major characteristics include.

MicroprocessorUsed as single processing power
RAM and cache technologyStores computation instructions for the CPU
SizeSmall and portable
Power consumptionLess power and heat
CostLess expensive
SpeedFast (computation time in picoseconds)
Programming languageHigh-level language
Input/outputKeyboard, mouse,…/monitor, printer,…
ExamplesAltair 8800, STAR 1000, CRAY-1

Fifth-generation computers –

The movement for the fifth-generation computers began in Japan in 1982 through the Ministry of International Trade and Industry. The project was initiated to create computers with parallel computing technology, pattern processing, and logic programming language.

ProcessingParallel processing & computing technology
PurposeCapable of learning and organizing
SpeedVery fast
Programming languageLogic programming & algorithms
ExampleApple Siri

Fifth-generation is used to refer to the computers that are capable of learning and organizing based on human behavioral algorithms. They are in continuous development and are based on Artificial Intelligence and Machine Learning.

These computers and machines are developed to perform some of the basic tasks of man. They use parallel processing to enhance speed and achieve real-time results. An example of natural language processing technology is Apple’s Siri, Google Assistance, and Microsoft Cortana.


There are five main classes of computers by generation:

  • First-generation computers used vacuum tubes and were developed between 1945 – 1956.
  • Second-generation computers used transistors and were developed between 1956 – 1963.
  • Third-generation computers used integrated circuits and were developed between 1963 – 1971.
  • Fourth-generation computers used microprocessors and were developed between 1971 – date.
  • Fifth-generation computers used parallel processing and were developed between 1982 – date.

Each of these generations of computers has its distinguishing features which were explained in this tutorial. Check out the classification of computers by type.

Leave a Reply

%d bloggers like this: