A campaign in Britain to build a room-sized prototype computer first envisaged in 1837 is gathering momentum, computer enthusiasts say.

Offers of money and support to build a working model of Charles Babbage's Analytical Engine have begun to come in, and campaign organizers hope to gather donations from 50,000 supporters to launch the project, the BBC reported Thursday.

Mathematician and engineer Charles Babbage designed the analytical engine, to be built of brass and iron and powered by steam, on paper.

Although elements and partial sections of the engine have been built over the last 173 years, a complete version has never been built.

"It's an inspirational piece of equipment," said John Graham-Cumming, author of the Geek Atlas, who has supported the idea. "A hundred years ago, before computers were available, [Babbage] had envisaged this machine."

Babbage's Analytical Engine is regarded as the first design for a "general purpose computer" that could be reprogrammed to carry out different tasks.

It was to be the successor to his Difference Engine, a huge brass numbers-cruncher.

"The Difference Engine is a calculator," said computer historian Doron Swade, who was part of a team that spent 17 years painstakingly building a replica. "It is not a computer in the general sense of the word."

It would be "astounding" if the Analytical Engine could also be built, he said.