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How Computers Evolved: A look at all the generations

Team StoryWeavers|September 30, 2019|

It’s 1795 and you’re the captain of a ship at sea. The sea in front of you is inky black. How do you know which direction your ship is going in? Simple! You estimate your location by the position of the stars above! You have a mathematical book that helps you with this, but there’s only one problem. These calculations are made by human mathematicians and they’re not always accurate. Wouldn’t that frustrate you?

That’s exactly what the British scientist Charles Babbage, the father of computers, thought too. Babbage wanted to build a machine that could perform accurate calculations quickly to avoid errors in navigation and engineering. This is when he came up with the design for the first computer called the Difference Engine in 1822.

But did you know that Babbage never actually built a computer? Babbage’s design for the computer was built nearly 120 years after he designed it! Today, computers are indispensable and help us in almost every aspect of our lives. Using the mathematical language called binary (which only uses the digits 0 and 1), computers store huge amounts of information and help us make lightning-fast calculations which we could have not done ourselves.

Let’s look at the journey of the computer right from the start and see how it has evolved to help us practically do everything.

 First-generation computers were built using vacuum tubes as the main technology. These computers were very fragile and were as big as a room! They could roughly perform 5000 additions or subtractions per second! These computers consumed a lot of electricity and produced a lot of heat. The heat generated by the computer would also attract insects into the machine which would make the machine malfunction. This is why when computers have an error we still say “There’s a bug in it!”. These computers were used during the Second World War to calculate the aim of ballistic weapons and decode messages.

Second-generation computers were built using transistors. Most of the development of transistors happened in Santa Clara Valley in the USA. And because transistors used silicon, this place was soon called Silicon Valley! Second-generation computers could perform roughly 5000 additions in a second but they were way more accurate! The only way to make transistor computers more powerful is to keep adding more transistors. This meant that a good transistor computer would need thousands of discrete parts to work well. 

Third-generation computers used integrated circuits that were made by fitting many transistors onto one chip. The development of ICs also gave rise to Moore’s Law that believes that every two years, twice the number of transistors can be fitted into ICs while the cost of the ICs reduces by half. Since the circuits in the ICs are very close to each other, the electricity in the circuit needs to travel a very small distance. This led to faster calculations! The computer still needed an air-conditioned environment to function in.

Fourth-generation computers run on microprocessors which are stamp-sized chips that contain all the important circuits needed for the computer to run. One of the earliest companies that made microprocessors was formed by combining the words integrated and electronics – Intel! These computers were also sometimes called microcomputers because they were so small compared to the computers in the past. The Apple II made by Apple is one of the earliest fourth-generation personal computers ever made and was hugely popular for personal use.

Fifth-generation computers may use neural networks and artificial intelligence and try to make decisions that mimic human beings. They can interpret information and make decisions. Since these computers can learn on their own, we are still figuring out the full extent of how to control them. These computers are used everywhere from entertainment, medicine, research and more. The world’s smallest computer (that can measure the temperature of cell clusters) is smaller than a grain of rice.

With computers going from the size of a room to being smaller than a grain of rice, what do you think will come next in modern computing? Would you like to be a future computer scientist?

Let us know in the comments.

About the Author

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Deepthi Chakravarthy

Deepthi is an ambivert who is on a steady diet of good food, filter coffee, and self-improvement. Being an ardent reader, storytelling has been her first love and she enjoys exploring how to convey stories compellingly. Having studied psychology and experienced the learning and development field, Deepthi is driven to understand human behavior and to know what makes each of us unique. You are most likely to find her tucked into a cozy corner at a local cafe with a Kindle or a book in hand. If you find her there, stop by and say hello, she'd be eager to learn your story too. Until then, you can ping her at for anything you may like to share.

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