The first computers

The word ‘computer’ used to mean a person, not a machine. In the nineteenth century, builders and technicians needed to know the answers to very difficult calculations in order to do their work. They did not have the time to do these calculations themselves, so they bought books of answers. The people who did the calculations and wrote the books were called computers.

In the 1820s, a British mathematician called Charles Babbage invented a machine that did very difficult calculations automatically. He called his machine a Difference Engine. He began to build his machine, but he did not finish it because he had a better idea.

In fact, more than a hundred and fifty years later, some technicians from Science Museum in London built Babbage’s Difference Engine. It is still in the museum today. The machine weighs three tones, and it is nearly two metres tall and three metres wide. And it works; in the early 1990s, it did a calculation and gave the right answer – 31 digits long!

Babbage did not finish making the Difference Engine because he started work on a machine called an Analytical Engine. The Analytical Engine could do more. It had a kind of memory. This meant that it was possible to write programs for it, building on each answer and doing more and more difficult calculations. For this reason, the Analytical Engine is often seen as the first real computer. However, Babbage never finished building this machine either!

A woman called Ada Lovelace worked with Babbage. She was the daughter of Lord Byron, a famous English writer. Ada was an excellent mathematician and understood Babbage’s ideas. She knew that she could do amazing calculations with the Analytical Machine, and she wrote a program for it. Although the machine was never built, Ada Lovelace was still the first computer programmer in the world. In 1979, a computer programming language was named ADA.

Babbage’s ideas were ahead of time. Over the next one hundred years, inventors began to build better calculating machines. One of the best inventors of the 1930s was a German called Konrad Zuse. In 1938, he built his first machine, the Z1. His later machines, the Zuse3 and Zuse4, were like modern computers in many ways. They used only two digits (0 and 1) to do all the calculations. Also, Zuse wrote programs for his machines by making holes in old cinema film. When he put the film through the machines, they could read the programs and do very long and difficult calculations.

(from Information Technology by Paul A.Davies, Oxford Bookworms Factfiles, Oxford University Press 2000)