Steam Computer Builders Scan Babbage’s Notes

Plans coming to fruition at the Science Museum in London could see the first computer program ever devised running for the first time after almost 170 years.

The museum has begun digitising the plans and notebooks of Charles Babbage (1791-1871) so that a team of engineers can access the documents to begin to construct Babbage’s Analytical Engine a mechanical device which, if Babbage had completed it, would have been the first true computer – in the Victorian era.

The project is the brainchild of John Graham-Cumming, a vice-president of engineering at CRM intelligence software maker Causata. He has taken on the personal challenge to see through the building of this steam-powered programmable computer designed in the 19^th century.

Steam-Driven Hardware

Charles Babbage (1791-1871) was a polymath who saw the possibility of the repetitive processes of computers (in his day, people who performed calculations) being performed by machine. His first invention in this area was the Difference Engine, a gigantic calculator, which he drafted and attempted, but failed, to build.

He revisited the project to create a revised design in later life – a project that was eventually realised by the Science Museum in 1991 where a Difference Engine No 2 and its associated printer have been working flawlessly for 20 years.

Despite the failure of Babbage to complete the project, he moved on to design the Analytical Engine in 1837, which took the calculator to the next step of using calculated results for use in further calculations according to rules input through punched paper cards – a programming technique adapted by IBM for its early mainframe electronic computers.

The machine would have employed several other features used in modern computers, including sequential control, branching, and looping (“if” and “goto” instructions). This defines the system as a computer, or Turing-complete, according to the definition laid down by Alan Turing in the mid-20^th century.

In 1843, Ada Lovelace (Ada King, Countess of Lovelace), a daughter of the celebrated poet Lord Byron, devised a method for calculating a sequence of Bernoulli numbers – widely accepted as the first example of a computer program. Lovelace’s vision of the uses of the Analytical Engine surpassed Babbage’s view of a mere calculating computer and she foresaw the possibilities of music being composed by machine and other data being represented numerically and manipulated – the concept of the modern computer.

Team Ready For Action

To build interest in the current Analytical Engine project, known as Plan 28 after Babbage’s numerical assignation for his detailed designs, Graham-Cumming last year recruited the help of Doron Swade, who masterminded the Science Museum project to build Babbage’s Difference Engine No 2. In July, 2011, the Computer Conservation Society, responsible for providing advice and assistance for many historical computer reconstructions, accepted the Analytical Engine into its project portfolio.

The digitising of Babbage’s designs will enable the construction team to access the original documents remotely in its attempt to realise the inventor’s dream. So far, only one section of the “mil”l of the Analytical Engine has ever been constructed – by Babbage’s son Henry Prevost Babbage in 1910.

The mill, on display at the Science Museum, is the mechanical CPU, capable of doing addition, subtraction, multiplication and division. The complete engine will be supported by a store (the memory); and cogs and barrels (effectively, the microcode for the mill operations).

Initially the scans will only be available to the project workers but the Science Museum hopes to make them available to science and technology researchers in 2012. Public access will follow at an unspecified date.