Nicholas Negroponte has demonstrated the first $100 laptop computer for use in developing countries.

He and an embarrassed Kofi Annan had to overcome technical glitches. The United Nations general secretary twisted off the computer's crank handle at the unveiling event, and the screen locked as Negroponte later tried to demonstrate the display.

Despite the hiccups, the MIT Media Lab chairman was visibly excited about the prospect of placing the device in the hands of millions of schoolchildren around the globe.

The hand-cranked laptop, shown for the first time at the U.N.-sponsored World Summit on the Information Society (WSIS), operates at 500MHz, or less than half the speed of most commercial laptops.

It features a low-power display that can be switched from colour to black and white to allow viewing in bright sunlight. Many children in developing countries attend school outside, Negroponte said.

The machine can be folded in different ways to serve as a computer, electronic book or media player. "We designed the device to perform many roles," said Negroponte, who also heads the One Laptop Per Child non-profit group. "Learning should be seamless."

The computer will run "Linux or some other open-source operating system," Negroponte said.

Applications will also be open-source based, and available in "every single language that people want," Negroponte said. The MIT professor said he expects the open source community to jump at the opportunity to pitch in with this effort.

The computers will be free to schoolchildren. "Ownership of the computer is absolutely essential," Negroponte said, pointing out that people generally take better care of things they own. "Have you ever washed a rental car?" he asked.

Choosing the colours - the body is lime green and the crank yellow -- was one of the hardest decisions the group had to make, Negroponte said. The colours should convey "a message of playfulness," he said.

Talks continue with manufacturers to build the computers, according to Negroponte. One company has offered to build them for around $110 per unit, and four others are still considering, he said. The goal is to drive the price lower as volume grows, he said.

The group plans to launch in six "big and very different markets," Negroponte said. One will be in the Middle East, two in Asia, one in sub-Saharan Africa and two in Latin America. Brazil and Thailand have shown the most enthusiasm, he said. Talks continue with Egypt and Nigeria, among others.

Negroponte hopes to launch the program in the six markets in February and March. "It all depends on when the machines are ready," he said.

Governments must buy 1 million laptops to participate in the program, according to Negroponte said. "That's their entry ticket," he said.

The laptops might become commercially available to the general public but at a higher price, possibly around $200, Negroponte said.

The list of supporters in the non-profit organization include Google and the media magnate Rupert Murdoch.