OLPC XO-1

The XO-1, previously known as the $100 Laptop or Children's Machine, is an inexpensive laptop computer intended to be distributed to children in developing countries around the world,^[1] to provide them with access to knowledge, and opportunities to "explore, experiment and express themselves" (constructionist learning).^[2] The laptop is developed by the One Laptop per Child (OLPC) social welfare organization, and manufactured by the Taiwanese computer company, Quanta Computer.

The laptops can be sold to governments and issued to children by schools on a basis of one laptop per child. Pricing is currently set to start at US$188 and the goal is to reach the $100 mark in 2008. Approximately 500 developer boards (Alpha-1) were distributed in mid-2006; 875 working prototypes (Beta 1) were delivered in late 2006; 2400 Beta-2 machines were distributed at the end of February 2007;^[3] full-scale production started November 6, 2007.^[4] Quanta Computer, the project's contract manufacturer, said in February 2007 that it had confirmed orders for one million units. It indicated it could ship five million to ten million units that year because seven nations have committed to buy the XO-1 for their schoolchildren: Argentina, Brazil, Libya, Nigeria, Rwanda, Thailand, and Uruguay.^[5] Quanta plans to offer machines very similar to the XO machine on the open market.^[6]

The OLPC project had stated that a consumer version of the XO laptop is not planned.^[8] However, the project established in 2007 the laptopgiving.org website for outright donations and for a "Give 1 Get 1" offer valid (but only to the United States, its territories, and Canadian addresses) from November 12, 2007 until December 31, 2007.^[9] It has been rumored that it is planning to put a modified version of Windows XP into their newer laptops.^[10]^[11]

[edit] History

The first early prototype was unveiled by the project's founder Nicholas Negroponte and then-United Nations General Secretary Kofi Annan on November 16, 2005 at the World Summit on the Information Society (WSIS) in Tunis, Tunisia. The device shown was a rough prototype using a standard development board. Negroponte estimated that the screen alone required three more months of development. The first working prototype was demonstrated at the project's Country Task Force Meeting on May 23, 2006. The production version is expected to have a larger display screen in the same size package.

In late September 2007, it was announced that the XO would be available in the United States and Canada to consumers for a short time for the Christmas season, starting November 12 for two weeks (later extended through the end of 2007), through a "Give 1 Get 1" (G1G1) program. This allowed consumers to purchase two XO systems for $399, with one sent to a child in a developing nation.^[9]

[edit] Design

The XO-1 is designed to be low-cost, small, durable, and efficient. It is shipped with a slimmed-down version of Fedora GNU/Linux and a GUI called Sugar that is intended to help young children collaborate. The XO-1 includes a video camera, a microphone, long-range Wi-Fi, and a hybrid stylus/touch pad. Human power is planned, allowing operation far from commercial sources of power.

Various use models had been explored by OLPC with the help of Design Continuum and Fuseproject, including: laptop, e-book, theatre, simulation, tote, and tablet architectures. The current design, by Fuseproject, uses a transformer hinge to morph between laptop, e-book, and router modes.

[edit] Hardware

[edit] Intentionally omitted features

In keeping with its goals of robustness and low power consumption, the design of the laptop intentionally omits all motor-driven moving parts; it has no hard drive, no optical (CD/DVD) media, no floppy drives and no fans. An ATA interface is unnecessary due to the lack of hard drive. There is also no PC card slot, although an SD slot is available, as well as USB ports.

A built-in hand-crank generator, making it self-powered equipment, was part of the original design, but Negroponte stated at a 2006 LinuxWorld talk that it was no longer integrated into the laptop itself, but that a similar device could someday be optionally available as a hand- or foot-operated generator built into a separate power unit.^[14]

[edit] Power consumption

The laptop will consume about 2 W of power during normal use, far less than the 10 W to 45 W of conventional laptops.^[3] With build 656 power consumption is between 5 and 8 watts. (Measured on G1G1 laptop) Future software builds should meet the target of 2 watts.

In e-book mode, which is still under development and has not yet been released, all hardware sub-systems are intended to be powered down except the monochrome display. When the user moves to a different page the system will wake up, draw the new page on the display and then go back to sleep. Power consumption in this future "e-book mode" is estimated to be 0.3 W to 0.8 W.

[edit] Display

The first-generation OLPC laptops have a novel low-cost LCD. Later generations of the OLPC laptop are expected to use low-cost, low-power and high-resolution electronic paper displays.

The display is the most expensive component of the OLPC Laptop. In April 2005, Negroponte hired Mary Lou Jepsen—who was then expected to join the Media Arts and Sciences faculty at the MIT Media Lab in September 2008^[19]—as OLPC Chief Technology Officer. Jepsen developed a new display for the first-generation OLPC laptop, inspired by the design of small LCDs used in portable DVD players, which she estimated would cost about $35.

Jepsen has described the removal of the filters that color the RGB subpixels as the critical design innovation in the new LCD. Instead of using subtractive color filters, the display uses a plastic diffraction grating and lenses on the rear of the LCD to illuminate the colored subpixels. This grating pattern is stamped using the same technology used to make DVDs. The grating splits the light from the #000000 backlight into a spectrum. The red, green and blue components are diffracted into the correct positions to illuminate the corresponding R, G or B subpixels. This innovation results in a much brighter display for a given amount of backlight illumination: while the color filters in a regular display typically absorb 85% of the light that hits them, this display absorbs little of that light.^[20]

The remainder of the LCD uses existing display technology and can be made using existing manufacturing equipment. Even the masks can be made using combinations of existing materials and processes.

In color mode, the display is lit from the back with a #000000 LED^[21]. Most LCD screens use cold cathode fluorescent lamp backlights which are fragile, require a high voltage power supply, are relatively power-hungry, and account for 50% of the screens' cost (sometimes 60%).^[22] In monochrome (grayscale) mode, the display is lit only by ambient light such as the sun.

Mode change may normally occur with a change in use of the device. The color display is expected to be used in laptop mode, whereas the portrait format monochrome display is expected to be used in tablet mode for reading pages of text. This is the so-called “curl-up-in-bed mode”^[23] to enable reading of e-books for an extended time in bright light such as sunlight.

In color mode, the display does not use the normal pixel geometry for liquid crystal computer displays, which makes each pixel contain tall thin rectangles of each primary color. Instead, the display provides only one color for each pixel. The colors align along diagonals that run from upper-left to lower right. (see diagram) To reduce the color artifacts that this pixel geometry causes, the image is blurred as it is sent to the screen. Despite the blurring, the display will still be decently sharp for its physical size; normal displays as of February 2007 put about 588×441 to 882×662 in this amount of physical area and support subpixel rendering for a tad more. A study reports the color resolution is effectively 984×738 a 984 x 738 perceptual resolution.^[24] A conventional liquid crystal display with the same number of green pixels (green carries most brightness information for human eyes) as the OLPC XO-1 would be 693×520. Unlike a normal 693×520, resolution varies with angle. Resolution is greatest from upper-right to lower left, and lowest from upper-left to lower-right. Images which approach or exceed this resolution will lose detail and gain color artifacts. There exist arguments that the color display gains resolution when in bright light; this comes at the expense of color (as the backlight is overpowered) and can never reach the 200 dpi sharpness of grayscale mode because of the blur which is applied to images in color mode.

[edit] Wireless mesh networking

IEEE 802.11b support will be provided using a Wi-Fi “Extended Range” chip set. Jepsen has said the wireless chip set will be run at a low bit rate, 2 Mb/s maximum rather than the usual higher speed 5.5 Mbit/s or 11 Mbit/s to minimize power consumption. The conventional IEEE 802.11b system only handles traffic within a local cloud of wireless devices in a manner similar to an Ethernet network. Each node transmits and receives its own data, but does not route packets between two nodes that cannot communicate directly. The OLPC laptop will use IEEE 802.11s to form the wireless mesh network.

Whenever the laptop is powered on it will participate in a mobile ad-hoc network (MANET) with each node operating in a peer-to-peer fashion with other laptops it can hear, forwarding packets across the cloud. If a computer in the cloud has access to the Internet—either directly or indirectly—then all computers in the cloud are able to share that access. The data rate across this network will not be high; however, similar networks, such as the store and forward Motoman project^[25] have supported email services to 1000 schoolchildren in Cambodia, according to Negroponte. The data rate should be sufficient for asynchronous network applications (such as email) to communicate outside the cloud; interactive uses, such as web browsing, or high-bandwidth applications, such as video streaming should be possible inside the cloud. The IP assignment for the meshed network is intended to be automatically configured, so no server administrator or an administration of IP addresses is needed.

Building a MANET is still untested under the OLPC's current configuration and hardware environment. Although one goal of the laptop is that all of its software be open source, the source code for this routing protocol is currently closed source. While there are open-source alternatives such as OLSR or B.A.T.M.A.N., none of these options is yet available running at the data-link layer (Layer 2) on the Wi-Fi subsystem's co-processor; this is critical to OLPC's power efficiency scheme. Whether Marvell Technology Group, the producer of the wireless chip set and owner of the current meshing protocol software, will make the firmware open source is still an unanswered question. But this matter will become clearer once the production is in full swing.

[edit] Shell

Yves Behar is the chief designer of the present XO shell. The shell of the laptop is resistant to dirt and moisture, and is constructed with 2 mm thick plastic (50% thicker than typical laptops). It contains a pivoting, reversible display, movable rubber WiFi antennas, and a sealed rubber-membrane keyboard.

[edit] Keyboard and touchpad

More than ten different keyboards have been laid out, to suit local needs to match the standard keyboard for the country in which a laptop is intended. Around half of these have been manufactured for prototype machines.^[26]^[17] There are parts of the world which do not have a standard keyboard representing their language. As Negroponte states this is “because there's no real commercial interest in making a keyboard”.^[27] One example of where the OLPC has bridged this gap is in creating an Amharic keyboard^[28] for Ethiopia.

Negroponte has demanded that the keyboard not contain a caps lock key, which frees up keyboard space for new keys such as a future “view source” key.^[29]

Beneath the keyboard is a large area that resembles a very wide touchpad that Jepsen referred to as the “mousepad”. The central third is a capacitive sensor that can be used with a finger; the full width is a resistive sensor which, while not yet operational, may someday be used with a stylus.

[edit] Software

Countries are expected to add and remove software to best adapt the laptop to the local laws and educational needs. As supplied by OLPC, all of the software on the laptop will be free and open source.^[29] All core software is intended to be localized to the languages of the target countries.^[30] The projected software as of November 2006^[31] are:

The laptop will use the Sugar graphical user interface, written in Python, on top of the X Window System and the Matchbox window manager.^[33] This interface is not based on the typical desktop metaphor but presents an iconic view of programs and documents and a map-like view of nearby connected users. The current active program is displayed in full-screen mode.^[3] Much of the core Sugar interface uses icons, bypassing localization issues. Sugar is also defined as having no folders present in the UI.

Steve Jobs had offered Mac OS X free of charge for use in the laptop, but according to Seymour Papert, a professor emeritus at MIT who is one of the initiative's founders, the designers want an operating system that can be tinkered with: “We declined because it’s not open source.”^[35] Therefore Linux was chosen. However, after a deal with Microsoft, the laptop will now be offered with Windows XP along with an open source alternative.^[36]

Jim Gettys, responsible for the laptops' system software, has called for a re-education of programmers, saying that many applications use too much memory or even leak memory. “There seems to be a common fallacy among programmers that using memory is good: on current hardware it is often much faster to recompute values than to have to reference memory to get a precomputed value. A full cache miss can be hundreds of cycles, and hundreds of times the power consumption of an instruction that hits in the first level cache.”^[13]

On 4 August 2006, the Wikimedia Foundation announced that static copies of selected Wikipedia articles would be included on the laptops. Jimmy Wales, chair of the Wikimedia Foundation, said that “OLPC's mission goes hand in hand with our goal of distributing encyclopedic knowledge, free of charge, to every person in the world. Not everybody in the world has access to a broadband connection.”^[37] Negroponte had earlier suggested he would like to see Wikipedia on the laptop. Wales feels that Wikipedia is one of the “killer apps” for this device.^[38]

Don Hopkins announced that he is creating a free and open source port of the game SimCity to the OLPC with the blessing of Will Wright and Electronic Arts, and demonstrated SimCity running on the OLPC at the Game Developer's Conference in March 2007.^[39] The free and open source SimCity plans were confirmed at the same conference by SJ Klein, director of content for the OLPC, who also asked game developers to create “frameworks and scripting environments—tools with which children themselves could create their own content.”^[40]^[41]

The laptop's security architecture, known as Bitfrost, was publicly introduced in February 2007. No passwords will be required for ordinary use of the machine. Programs are assigned certain bundles of rights at install time which govern their access to resources; users can later add more rights. Optionally, the laptops can be configured to request leases from a central server and to stop functioning when these leases expire; this is designed as a theft-prevention mechanism.

[edit] Software alternatives

Xfce is a lightweight alternative GUI to Sugar. Being only 33 MB (using yum) it does not take up much of an XO's storage space - less than GNOME or KDE. According to the OLPC Wiki: "Xfce is a lightweight but powerful desktop environment that will work well on the XO"^[42] It is by far the most common alternative GUI. Information on installation is available at: OLPC Wiki: Xfce.

[edit] See also