Building the Analytical Engine

April 30, 2012

I’ve written here before about the project, launched by John Graham-Cumming, a British writer and programmer, to build a working model of the Analytical Engine, designed in the 19th century by the British mathematician, Charles Babbage.  The Engine, which has a fair claim to being the world’s first design for a stored-program computer, was never built, owing to its size (about the same as a steam locomotive) and complexity.  Lord Byron’s daughter Ada, Lady Lovelace, for whom the Ada programming language is named, wrote a program for the Analytical Engine to compute Bernoulli numbers, and was possibly the world’s first programmer.

Last fall, the Science Museum in London undertook the digitization of Babbage’s various designs for the Engine (he was an inveterate tinkerer), with the aim of coming to a final design for the proposed replica.

There is now a video available of a TED talk that Mr. Graham-Cumming gave at Imperial College, London, on the Analytical Engine project, in which he discusses the design of the Engine and how the project is proceeding.  Although it’s not a comprehensive description, it’s an entertaining overview of the problem.

Building the Analytical Engine: Update

September 22, 2011

Last December, I wrote about the project, launched by John Graham-Cumming, to build a working implementation of the Analytical Engine, designed by the British mathematician Charles Babbage.  Babbage’s design was arguably the first for a stored-program computer, although it was a completely mechanical — and steam powered! — device.  Nonetheless, it incorporated features common in today’s computers, including branching, looping, and expandable memory.

The BBC site reports that the Science Museum in London is undertaking a first step in organizing the extant design information for the project.

A project to construct one of the earliest mechanical computers based on sketches by its designer, Charles Babbage, has received a major boost.

The Science Museum in London has agreed to help by digitising the mathematician’s original plans.

The aim is to make the designs, which in their original form are in the Science Museum’s archives, more accessible to a wider range of people.  Once the designs are available for study, a follow-up step will be to develop a computer simulation of the Analytical Engine.  This will allow those studying the plan a chance to test their interpretations of Babbage’s notes and drawings, without building the full-scale machine, which Mr. Graham-Cumming estimates will be about the size of a small steam train.

Mr. Graham-Cumming has also developed some rough estimates of the Analytical Engine’s potential computing power.

Its memory would be equivalent to around 675bytes, or just over half that of Sinclair’s ZX81, released in 1981. A later proposal by Babbage called for 20KB of storage.

The machine’s clock speed would work out at around 7Hz, compared to the ZX81’s 3.2MHz.

Although it will take several years before a physical implementation of the machine is attempted, a tentative goal is to complete a working Analytical Engine by 2021, the 150th anniversary of Babbage’s death.

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