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Last Updated: Friday, 24 August 2007, 16:39 GMT 17:39 UK
Under the hood of the $100 laptop
By Andrew Webb

$100 Laptop's chief software engineer Chris Blizzard on how the innovative memory and screen save energy.

A team of US-based researchers, backed by a wealthy philanthropist, have re-invented the computer in an attempt to revolutionise education in the developing world.

The engineers who designed the energy efficient laptop have thrown out a whole host of conventional ideas in order to produce a computer that will be useful in nations where electricity is in short supply.

Prototype laptop
Dubbed the $100 laptop, though the first models are more likely to cost $170, the light and robust machine outwardly resembles a toy but look inside and it reveals itself to be a very serious device.

At its heart is a processor running at 433 Mhz - fast enough to write an essay, surf the internet, or make a video call.

Power saving

This is throttled back so it stays cool on its own without the need for a power guzzling fan. It is the first of many tricks that ensure the battery can power the laptop for 13 hours.

More energy is saved by removing the need for a backlight on the display. It uses natural light so it can be read in brilliant sunshine.

The piece de resistance is that when the computer goes to sleep and the CPU is hibernating the screen is still readable.

Data design

The engineers have also re-thought storage.

"One of the things in laptops that take up a lot of power is actually the hard drive. It is actually spinning around as a motor. It just uses up a lot of power," said OLPC designer Chris Blizzard.

"...there are no moving parts that require motors. It also has to do with reliability but it is mostly to do with power at this point.

"And there is a storage chip that is on the motherboard where you put your files instead of a hard drive."

Students with laptops at a school in Nigeria
Field testing of the laptops was done in Nigeria and Brazil
The XO operating system for the OLPC is custom built and adapted from Linux to slash the amount of power the chip requires. It uses applications which make far fewer demands on the processor than in a conventional computer.

The laptop is expected to be used in schools so educational programs feature heavily in its software roster.

It also has onboard programs familiar to even the most sophisticated users in the developed world, like a web browser, adapted from Firefox.


Getting connected is done via the miniature antennae which, like FM radio aerials, can be moved to receive the best wi-fi signal. That cuts power usage compared to concealed wi-fi cards, which drain batteries quickly when struggling to receive weak signals.

The plan is to use the laptops to form a mesh wi-fi network to spread net access around remote villages. Each machine relays data to its neighbours until the information reaches a satellite base unit that connects directly to the world wide web.

What we are hoping is you will be able to get a 10 to one ratio - that is for each minute you pull and crank on the laptop you can get 10 minutes use out of it
Chris Blizzard, designer
In stand-by mode the laptop should be able to act as a wi-fi router for around 24 hours without being charged.

When the laptop does need charging, but electricity supplies are scant, good old-fashioned elbow grease can generate power.

"One of the things that has been developed in concert with the laptop is a device that can be used to power it," said Mr Blizzard.

The OLPC is fitted with a ripcord that owners can crank to power up the device.

"What we are hoping is you will be able to get a 10 to one ratio - that is for each minute you pull and crank on the laptop you can get 10 minutes use out of it."

The naysayers

Despite the success of the design, established aid agencies have criticised the concept of giving computers to some of the most impoverished nations.

"The big priorities for all these countries need to be to get all children into schools in a manageable class size," said David Archer of Action Air International.

"That means employing more teachers and having some fundamentally basic materials in schools. I am afraid that putting laptops into the schools is not the first priority for these countries."

But with backing from the likes of Google, Wikipedia, and AMD, the One Laptop Per Child Project's founder is brushing aside comments from non-believers.

Nicholas Negroponte
Professor Negroponte first proposed the laptop in 2002
"Keep in mind I don't have shareholders. It makes no difference to us whether so many go out one quarter [or not]," said Nicholas Negroponte.

"What we want to maximise is how fast children get these around the world or get alternates to this."

The competition

Nevertheless, the One Laptop Per Child Project is facing serious competition from at least two directions.

"The first front is from Intel, which has a classmate PC project. It is significantly more expensive, estimated at $400," says Ken Fisher from Ars Technica, a PC enthusiasts website.

"Also Microsoft has announced that it is selling a reduced rate Windows and Office package for $3 in certain countries."

"So, in terms of the project not being able to worry about money I think that is a very naive point of view."

'$100 laptop' production begins
22 Jul 07 |  Technology
Intel and $100 laptop join forces
13 Jul 07 |  Technology

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