First Generation of Computers

First Generation of Computer

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Thanks to rapidly advancing technology, we are in the modern trendy world of the internet and computers. Computers have been around us longer than we think. The first computer came out in the late 1940s and early 1950s and has been an integral part of our lives ever since. With the arrival of each new generation of computers, technology has only left us in awe and wonder making our tasks simpler by the day. 

Let us dig deep and get to know the very first generation of computers a little better.

What is the first generation of computers?

The first generation of computers, also known as vacuum tube computers, lies between the years 1946 and 1959. They refer to the early stages of computer development when the first known computers came into existence. The development started in the late 1940s. They mainly used the technology of Vacuum tubes as the basic component for memory and calculations.

These computers relied upon the lowest level of programming language which is the machine language for all their programming. They used punch cards and magnetic tapes for input and storage. The outputs were always given as printouts on paper tapes.


What are Vacuum tubes? 

Vacuum tubes are electron tubes that control the motion of electrons and hence electrical current in a high vacuum space. Vacuum tubes also help in amplifying the power of signals using vacuum tubes. These tubes used a lot of electricity and produced a lot of heat.

Some  of the First Generation of Computers

ENIAC (Electronic Numerical Integrator And Computer)

ENIAC is one of the first-generation computers and the first general-purpose electronic computer. Built in the year 1943 at the University of Pennsylvania’s Moore School of Engineering with government funds, ENIAC used almost 18000 vacuum tubes and was huge in size and weighed almost 30 tons.

ENIAC used plugboard programming where programming had to be done physically and required a significant amount of time and effort. It was mainly used in military applications and ballistic calculations. Despite all its shortcomings, ENIAC opened gates for development and inspired scientists and engineers to strive for future development.

First Generation of Computer - Vacuum tubes
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UNIVAC (Universal Automatic Computer)

Another one in the first generation of computers, UNIVAC was the first commercially available electronic computing device. It was a general-purpose computer designed for both scientific and commercial applications. As compared to ENIAC, this one used around 5200 vacuum tubes as the primary electronic component along with punch cards, paper tapes, and magnetic tubes.

Instead of machine language, this computer used assembly language that involved writing instructions in mnemonic codes. UNIVAC motivated scientists and engineers into believing that computers were useful in not only scientific calculations but were useful in general data processing and analysis too.


EDSAC (Electronic Delay Storage Automatic Computer)

Developed at the University of Cambridge, EDSAC aimed at overcoming the limitations of the previous computers and facilitating scientific calculations and research. As the name suggests, this computer overcame the limitation of storage and stored both the instructions and data in the same memory. EDSAC marked a revolution in the development of the fields of computer architecture and computer programming.

Technology used in the First Generation of Computers

  • They essentially used vacuum tube technology.
  • They supported only Machine Language programming.
  • They work on batch-processing operating systems.
  • They used Punch Cards as an Input device.
  • Magnetic tapes were used as storage devices.
  • Paper tapes were used for output and output was only given as printouts.

Advantages of First-Generation of Computers

  • They were the fastest computation machines of their time.
  • They performed computations in milliseconds.
  • They were robust and were difficult to be damaged physically.
  • They revolutionized the development of electronic machines called computers and marked the beginning of the digital era that we live in.

Disadvantages of First-Generation of Computers

  • They were enormous and required large rooms for installation.
  • Once installed they were not movable due to their huge size and weight.
  • They were very costly and required high maintenance.
  • They consumed a really large amount of electricity.
  • Their capabilities were limited.
  • Vacuum tubes produced a lot of heat hence making air conditioning and cooling systems necessary.
  • Their maintenance costs were high.


Although the first generation of computers had more cons than pros, they marked the beginning of a revolution. The first generation of computers led to the further development and creation of second-generation computers all the way to the handy devices we now know of. It is important to know and acknowledge the history that led to this digital era making our tasks simpler than ever.


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