UNITED STATES. A revolutionary cut-price laptop is expected to widen dramatically the use of information technology in schools across the world.

US scientists have unveiled details of a $100 (pound;57) wind-up machine which they expect to triple global laptop production and extend computer and internet access to hundreds of millions of the world’s poorest pupils.

But the first beneficiaries may be teenagers in the United States and other rich countries where the low price will enable schools to buy in bulk.

Alan Kay, president of educational technology think-tank Viewpoints Research Institute and a consultant to the project, said the device was so cheap it should enable schools to buy laptops in bulk. It was a breakthrough equivalent to “Roger Bannister and the four-minute mile”.

In Massachusetts all the state’s 500,000 secondary-school students are expected to receive the machines from 2007 under a $56 million plan that would represent America’s most ambitious schools laptop programme to date.

The scientists hope the wind-up mechanism and low price will help pupils bridge the digital divide in the vast areas of Africa and Asia where electricity is uncertain or non-existent.

The laptop, developed at Massachusetts Institute of Technology (MIT), has already attracted interest from Brazil’s president, Thailand’s prime minister and Egypt’s education minister, and is expected to be distributed to between five and 15 million students in these countries, plus China and South Africa, from late next year.

Set to be formally unveiled at the United Nations’ technology summit in Tunisia next month, the laptop can be plugged in but has a side-mounted hand crank to generate power in remote areas without electricity. However, winding up the machine currently only provides 10 minutes of power.

Nicholas Negroponte, director of MIT’s Media Lab, said the laptop, which will also be distributed to teachers, would open up possibilities for pupils in developing nations.

To drive down the price, engineers have stripped out extraneous features and configured the laptop around key school-related tasks such as word processing, running educational software and surfing the web. Microsoft Windows has been replaced by the free operating system Linux.

The ultra-low price tag was also achieved by eliminating the sales and marketing overheads incurred by commercial laptop manufacturers. The scheme is being administered by a charitable foundation, One Laptop Per Child, which plans to negotiate bulk-buying deals with international education ministries.

However, the pound;56 price is still more than the typical monthly wage of a teacher in many of the poorest countries.

Professor Negroponte said shunning the profit-driven approach will allow savings from future technological advances to be passed directly onto education systems. ”$100 is still too expensive. We’ve told governments the price is going to go down.” Production of the laptops could reach 100 million to 150 million by December 2007, he predicted.

America’s most extensive school computer scheme so far has been a $35m initiative in Maine where 40,000 12 to 14-year-old pupils have been given laptops. Jeff Mao, Maine’s coordinator of educational technology, said the new machines’ price was “compelling”.