Celebrity inventor Trevor Baylis has said he is "not convinced" that Nicholas Negroponte has got very far with the $100 laptop he is developing for the Third World.

Baylis, who invented the clockwork wireless radio, was recently invited to MIT Media Lab to meet Negroponte and see the prototype, but said that it "could have put together with a Lego kit".

"Nothing worked. I was expecting him to show me the screen in action or the wind-up feature, but I saw nothing but a basic prototype," he said.

"If Negroponte has done it, full marks to the guy, but I am not 100 per cent convinced. It was all something of a PR stunt."

Baylis clearly has a lot to contribute to the project as he invented a wind-up radio that is now used widely in the Third World. He also lays claim to demonstrating the world's first wind-up computer.

"A few years ago I was in Botswana seeing the radio in use and people from Apple were there," he explained. "So for fun we hooked up my wind-up system to their eMate. We managed to get the screen to activate for a few seconds which amazed everyone."

Baylis believes he could develop wind-up technology for the MIT laptop but questioned whether such technology is currently available.

"The hard part is not developing the wind-up technology but finding a low-power screen," he said. "I would love to be involved in something like this. I have seen what an impact on lives my radio has had. This could be the same."

But Baylis said he came away from Boston feeling non-plussed. "Negroponte did not ask me to provide the technology," he complained. "He was more interested in looking at my wind-up torch, which I didn't develop anyway. I bought it in China for £3."

Baylis is keen for a UK initiative to make an attempt at a similar device. "HP has told me that the screen can't be made yet, but you never know," he explained. "Perhaps we can all get together and make it happen."

Lee Felsenstein, designer of the Osbourne computer, is working on a similar wind-up computer project. The details are on his blog here. 

Meanwhile the US National Science Foundation is funding the Technology and Infrastructure for Emerging Regions project at the University of California, Berkeley.

Michael Robertson, chief executive at open source firm Linspire, said that his company has researched the viability of the project and has deemed it inadequate.