Computers 101 – Who Invented the Computer?

It is not easy to answer who invented the computer because people have their own interpretation as to what a computer is. But the scholarly consensus today is that the abacus or the slide rule was the first. It was invented in 1622 by William Oughtred. But the first computer that had any resemblance to modern machines was Charles Babbage’s Analytical Engine, conceived between 1833 and 1871. Babbage was a British mathematician.


Prior to Babbage’s invention, a computer consisted of groups of people subtracting and adding numbers all day and placing the results in tables. This project was started by Napoleon Bonaparte for use in the military and tax collecting. But Napoleon ever got to publish these and they ended up in Paris’ Académie des sciences. In 1819 Babbage went to the city and saw the figures. It was at that point he wondered if there was a quicker way to crunch those figures.

The Difference Engine

When Babbage returned to the UK he began conceiving the Difference Engine which would use the finite differences principle. The engine / machine would be capable of performing complex calculations by adding repeatedly. In 1824 he got funding from the government and spent the next 8 years working on it. By 1832, he had come up with a prototype but by then the money had run out.

Analytical Engine

Undaunted, Babbage decided to pursue his work Rather than make a simpler version of his Difference Engine to cut costs, he conceived of an even more complex machinery which he called the Analytical Engine. Unlike the Differences Engine which was limited to performing additions, his Analytical Engine would be able to multiply and divide numbers. The basic components of the Analytical Engine are similar to computer parts today.

The Analytical Engine had memory and a central processing unit (CPU). Babbage of course, did not call it a CPU but instead a mill. As for the memory he called it the "store". The machine also had a reader used for inputting instructions. His system also provided a way to record the machine’s results on paper. Babbage called this output the printer, which does exactly what modern printers do.

From Vision to Reality

Babbage’s computer however, existed only on paper, as the day’s technology simply did not make it possible for the machine to be built. But he did keep more than 5,000 pages of notes and sketches of the Analytical Machine. In his notes Babbage showed he had a pretty good idea of how the machine will run. Basically data would be inserted using punch cards, and the engine could store up to 1,000 50-digit numbers.

The punched cards would carry out the order. Unlike other engines in the past, it could be run by a single person. Under Babbage’s vision, the unit could be powered by steam and use rods, cranks and gear wheels. But because of limitations in the technology, his invention stayed on paper.

While most agree that it was Babbage who invented the computer, it was not until 1991 that scientists and engineers were able to built the Analytical machine according to the specs Babbage provided. That was the year when the London Science Museum finally built the Analytical / Difference Engine. It is 7 feet tall and 11 feet long with 8,000 moving parts.

Dick is a computer expert and he shares his knowledge on invention of computers.

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