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Geek plans to build Babbage computer

Self-confessed geek John Graham-Cumming is launching a project to build British mathematician Charles Babbage's largely theoretical device which predicted just about every aspect of modern computing 100 years before the rest of the world cottoned on.

Babbage published a paper in 1837 which described the Analytical Engine, a brass and iron mechanical behemoth capable of carrying out and storing the results of complex calculations.

"Anyone intimate with the details of electronic computers will instantly recognise the components of Babbage's machine," says Graham-Cumming. "His Engine has a central processing unit (which he called the mill) and a large amount of expandable memory (which he called the store). The operation of the Engine is controlled by program stored on punched cards, and punched cards can also be used to input data.

"Inside the mill, individual operations are controlled by the equivalent of a microprogram. The microprogram is stored on cylinders covered in studs (much like in a music box) that Babbage refers to as the barrels. Data is transferred from the store to the mill for processing and returned to the store for later use."

In his plans Babbage described an Engine with 100 storage locations holding 40 decimal digits each (which is roughly equivalent to 1.7KB). He even anticipated the need for memory expansion, describing an Engine with 1,000 storage locations (17KB) and external storage on punch cards.

Babbage's work was largely ignored until the 1940s when Bletchley Park code breaker Alan Turing started to design and build mechanical computing devices.

Various parts of the Analytical Engine have already been replicated and can be seen in museums all over the world, but no-one has ever assembled all of the component parts into a complete working model.

London's Science Museum has already demonstrated that Babbage's inventions could have been built during his lifetime by creating the Difference Engine No 2 using historically accurate tools and materials.

Graham-Cumming has launched the project called Plan 28 to raise funding for the project which would first simulate the hardware on a modern computer.

"Simulating the machine using 3D modeling software and a physics engine would enable us to bring the machine to life without making any metal parts," he says. "Given the size and complexity of the machine, this step is vital. And since the final machine would wear out if constantly used, it would provide a way of demonstrating the Engine."

Babbage's original research was brought to an end because the government at the time withdrew funding for a costly project with no palpable outcome. A level of shortsightedness Graham-Cumming hopes will not be repeated when it comes to obtaining funding for the current project.

"What seemed like costly research that was unlikely to have any short-term value turned out to be the seed of one of the greatest revolutions mankind has seen. I hope that future generations of scientists will stand before the completed Analytical Engine, think of Babbage, and be inspired to work on their own 100-year leaps."