The history of the computer, from the abacus to the supercomputer

The computer hidden in the phone or laptop on which you are reading this is thousands of times more powerful than the room-sized computers of a few decades ago. But the journey began with simple counting beads. Here is the history of the computer in simple words — from the first counting tools to today's supercomputers.

From counting machines to computers

Charles Babbage: the father of the computer

In the 19th century the British mathematician Charles Babbage designed the "Analytical Engine", which had parts like a modern computer — a way to put data in, a "mill" to calculate, a "store" to remember and a way to print results. For lack of money and technology the machine was never completed in his lifetime, yet he is called "the father of the computer". His collaborator Ada Lovelace wrote a method of calculation for this machine, so she is regarded as the world's first "programmer".

The five generations of computers

• First generation (about 1940–56) — vacuum tubes: ENIAC had about 17,500 vacuum tubes, weighed about 27 tonnes and filled a large room.
• Second generation (about 1956–63) — transistors: the transistor was invented in 1947 at Bell Labs in the USA, making computers smaller, cheaper and more reliable.
• Third generation (about 1964–71) — integrated circuits (ICs): many transistors on one small chip.
• Fourth generation (from 1971) — microprocessors: a whole processor on one chip, which made personal computers and laptops possible.
• Fifth generation — artificial intelligence: computers that can learn, understand language and help with decisions.

Did you know? A famous story about calling a computer fault a "bug" dates from 1947. When the Harvard Mark II computer in the USA developed a fault, a real moth was found trapped inside. Grace Hopper's team taped it into the logbook and wrote, "First actual case of bug being found." Engineers had used the word "bug" before, but this story became very famous.

Computers in India

India's first indigenous computer, TIFRAC, was built at the Tata Institute of Fundamental Research in Mumbai and began working around 1960. In 1991 C-DAC in Pune, led by Dr Vijay Bhatkar, built the "PARAM 8000" supercomputer, at a time when India was having difficulty buying supercomputers from abroad. Read the full story in India's first computer: from TIFRAC to PARAM. Today, under the "National Supercomputing Mission", many supercomputers in India help with weather forecasting, science and research.

Moore's law

In 1965 Gordon Moore, co-founder of Intel, said that the number of transistors on a chip would double roughly every two years. The prediction held roughly true for decades, which is why computers kept getting faster, smaller and cheaper every few years. Today the chip in an ordinary smartphone holds billions of transistors.

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