First Working Model of OLPC $100 laptop

In a related vein, Kendall Clark has a post called “On the Joys of Primitive Computing” in which he lauds the AlphaSmart Neo, an inexpensive computer that runs up to 700 hours on three AA batteries.

I have an AlphaSmart Dana, which has a similar shape but is based on the Palm OS. It runs up to 25 hours on three AA batteries and recharges over USB. The keyboard is fantastic, and the instant bootup makes it ideal for notetaking. The audio sucks, though....

Thanks for that, David. I was most impressed with how carefully power management was planned. "Under typical use, the computer should last the entire school day without requiring charging." -- wouldn't that be great on plane rides!

Early photos showed the laptop with a hand crank to charge the batteries. That appears to have been abandoned because it could reduce the ruggedness of the computer housing and may not be that efficient in the first place.

from the wiki:

* The power supply is tolerant of almost any voltage you might have at hand for charging, either from a human powered generator or a car or truck battery; accidental reversal of polarity will not damage the machine.

* NiMH batteries are chosen to enable high charging efficiency from a generator (LiION batteries require very close control of charging voltages, so any higher voltage would have to be clamped and power wasted). Additionally, NiMH batteries have no safety problems (LiION batteries, when they fail, can fail by burning at extremely high temperature). And LiION batteries should be recycled carefully. NiMH batteries pose no environmental concerns.

* Power-efficient processor & electronics. Consumes 1/10th the power of "normal" notebooks

* Long battery life == more useful. Under typical use, the computer should last the entire school day without requiring charging. Avoiding disruption in class rooms, and/or the need for wiring (or use of generators) in the class room for power is very important.

* Careful attention to environmental issues, no hazardous materials, fully ROHS (Reduction of Hazardous Substances) compliant.

Some interesting audio notes from the wiki:

• Audio: Analog Devices AD1888 AC97-compatible audio codec
  
• Stereo audio with internal stereo speakers and a stereo line-out jack
  
• Internal microphone, plus a [monophonic] mic-in jack
  
• The audio codec can be used in a mode where direct voltage measurements can be taken, enabling children to learn about temperature, voltage, and many other physical phenomena with cheap sensors without requiring any external adaptors.