Intel and OLPC lower the cost and increase reliability of their computers by eliminating the hard disk and a using smaller screen. But they still build the units essentially the same way as conventional laptop computers: with components mounted in a clam shell case and connected by wires. The many parts and wires increase the cost and lower the reliability.
Instead, imagine opening a laptop with screen folded right back to be flat on the desk and then removing the hinge. This would result in a design in one fixed case, with the screen above the keyboard. This design was used by the Cambridge Z88, a number of other 1980s portable computers, most mobile phones and pocket calculators.
The mobile phone industry has the wholesale cost of phones to below US$30. and calculators are available for under $5. This can be done because the phones and calculators are made of a few components all mounted on one printed circuit board. This eliminates most of the wires, plugs, sockets and screws, reducing the cost and increasing reliability.
A workable design for the $50 PC might be the size of an A4 portrait page: 297 mm high by 210 mm wide. From the side it would be a wedge: 10mm high at the front, rising to 64 mm at the back. The wedge shape would provide about the same angle as a PC keyboard for comfortable typing and allow enough room under the back for the batteries. This would look a little like the Kyotronic KC-85/NEC PC-8201a/Tandy 100 of the 1980s.
The single printed circuit board would hold all electronic components, as well as the screen and keyboard. The individual electrical contacts for the keyboard keys would be printed directly on the circuit board, as would be the antenna for wireless communication. The rubber keyboard would be molded to cover the whole front of the unit, including around the touch pad, up and round the screen, down the sides and around plugs and sockets. This would form a dust and water resistant gasket as well as hold the case together without the need for any screws.
The back of the unit would be made of one molded piece of plastic. The unit would have no conventional laptop chassis, with the printed circuit board simply sandwiched between the front and back of the case. The batteries would be mounted directly in a molded indentation in the case, with no separate battery compartment and no screws.
Such a unit could prototyped, with the case made using Solid freeform fabrication, an off-the-shelf single board computer (SBC), LCD screen, and keyboard. Test units could be made in low volumes by hand. The production unit would suit mass production, or small scale manufacture.
The unit's relatively large case would allow the use of lower cost components than the Classmate PC and $100 laptop. The case could be designed to take different sized LCD screens, depending on availability. There would be room for low cost "sub-C" size rechargeable batteries as commonly used in portable drills. The back of the case could be molded around the battery pack to provide a carrying handle.
But such products are unlikely to succeed through good design alone. They also need a publicity grabbing gimmicks. The original design for the $100 laptop had a hand powered crank. This is obviously impractical and has not been included on later units, but was a useful promotional feature. Some ideas for the $50 laptop could be:
- LIGHT UP KEYBOARD: If the keyboard is made from translucent material, there should be enough stray light from the back light of the LCD screen to illuminate the keys. This would look very impressive in promotional demonstrations, photos and videos, with whole case of the unit glowing.
- VEHICLE MOUNTING: If the unit was made smaller (180 x 200 mm), it could be mounted in the standard "DIN" slot of a car dashboard. This would be the width of a standard car radio and four times the height (quad-DIN). As an example the Indian designed Reva NXG show car has a Linux tablet computer mounted in the dashboard. It could be used for entertainment, navigation, business (taxis and buses). Such a mounting could also be used for low cost Internet kiosks and public access computers in libraries, with the PC securely mounted into a wall or desktop.