OLPC XO-1

The XO-1, previously known as the $100 Laptop,[2] Children's Machine,[3] and 2B1,[4] is an inexpensive subnotebook computer intended to be distributed to children in developing countries around the world,[5] to provide them with access to knowledge, and opportunities to "explore, experiment and express themselves" (constructionist learning).[6] The laptop is developed by the One Laptop per Child (OLPC) non-profit, 501(c)(3) organization and manufactured by Quanta Computer.

The subnotebooks are designed for sale to government-education systems which then give each primary school child their own laptop. Pricing was set to start at $188 in 2006, with a stated goal to reach the $100 mark in 2008 and the 50-dollar mark by 2010.[7] When offered for sale in the Give One, Get One campaigns of Q4 2006 and Q4 2007, the laptop was sold at $199.[8]

These rugged, low-power computers use flash memory instead of a hard drive, and come with a distribution of Linux derived from Red Hat's Fedora as their pre-installed operating system with the new Sugar GUI.[9] Mobile ad hoc networking via 802.11s WiFi mesh networking protocol is used to allow many machines to share Internet access as long as at least one of them can see and connect to a router or other access point.

The XO-1 is also nicknamed ceibalita in Uruguay after the Ceibal project.

Design

The XO-1 is designed to be low-cost, small, durable, and efficient. It is shipped with a slimmed-down version of Fedora Linux and a GUI named 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. In addition to a standard plug-in power supply, human power and solar power sources are available, allowing operation far from a commercial power grid. Mary Lou Jepsen has listed the design goals of the device as follows:

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

Hardware

The latest version of the OLPC XO is XO-4. The specs for older builds are documented in the Major Builds section, below. Data about the XO-1 comes from the hardware specification.

1. XO-1 motherboard
2. XO 1
3. CPU: 433 MHz x86 AMD Geode LX-700 at 0.8 watts, with integrated graphics controller
4. 256 MB of Dual (DDR266) 133 MHz DRAM (in 2006 the specification called for 128 MB of RAM)[29]
5. 1024 kB (1 MB) flash ROM with open-source Open Firmware
6. 1024 MB of SLC NAND flash memory (in 2006 the specifications called for 512 MB of flash memory)[30]
7. Average battery life 3 hrs
8. XO 1.5[31]
9. Release Date early 2010
10. CPU: 400 MHz to 1000 MHz x86 VIA C7 at 0.8 watts, with integrated graphics controller
11. 512 to 1024 MB of Dual (DDR266) 133 MHz DRAM
12. 1024 kB (1 MB) flash ROM with open-source Open Firmware
13. 4 GB of SLC NAND flash memory (upgradable, microSD)
14. Average battery life 3-5 hrs (varies w/ active suspend)
15. XO 1.75[32][33]
16. Release Date TBD late 2011 ?
17. CPU: 400 MHz to 1000 MHz ARM Marvell Armada 610 at 0.8 watts, with integrated graphics controller
18. 1024 to 2048 MB of DDR3 (TBD)
19. 1024 TBD kB (1 MB) flash ROM with open-source Open Firmware
20. 4-8 GB of SLC NAND flash memory (upgradable, microSD)
21. Accelerometer
22. Average battery life 5-10 hrs
23. Screen
24. 1200×900 7.5 inch (19 cm) diagonal LCD (200 dpi) that uses 0.1 to 1.0 W depending on mode. The two modes are:
25. Reflective (backlight off) monochrome mode for low-power use in sunlight. This mode provides very sharp images for high-quality text.
26. Backlit color mode, with an alternance of red,green and blue pixels. See below for details.
27. XO 1.75 developmental version for XO-3 has an optional touch screen
28. Storage
29. Internal SD card slot[34]
30. Wireless
31. Wireless networking using an “Extended Range” 802.11b/g and 802.11s (mesh) Marvell 8388 wireless chip, chosen due to its ability to autonomously forward packets in the mesh even if the CPU is powered off. When connected in a mesh, it is run at a low bitrate (2 Mbit/s) to minimize power consumption. Despite the wireless chip's minimalism, it supports WPA.[35] An ARM processor is included.
32. Dual adjustable antennas for diversity reception.
33. Inputs/Ports
34. Water-resistant membrane keyboard, customized to the locale in which it will be distributed.[36] The multiplication and division symbols are included. The keyboard is designed for the small hands of children.
35. Five-key cursor-control pad; four directional keys plus Enter
36. Four "Game Buttons" (functionally PgUp, PgDn, Home, and End) modeled after the PlayStation Controller layout (Triangle, Circle, Cross, and Square).
37. Touchpad for mouse control and handwriting input
38. Built-in color camera, to the right of the display, VGA resolution (640×480)
39. Built-in stereo speakers
40. Built-in microphone
41. Audio based on the AC'97 codec, with jacks for external stereo speakers and microphones, Line-out, and Mic-in
42. 3 external USB 2.0 ports.
43. Power sources:
44. DC input, ±11–18 V, maximum 15 W power draw
45. 5-cell rechargeable NiMH battery pack, 3000 mAh minimum 3050 mAh typical 80% usable, charge at 0…45°C (deprecated in 2009)
46. 2-cell rechargeable LiFePO4 battery pack, 2800 mAh minimum 2900 mAh typical 100% usable, charge at 0…60°C
47. 4-cell rechargeable LiFePO4 battery pack, 3100 mAh minimum 3150 mAh typical 100% usable, charge at −10…50°C
48. External manual power options included a clamp-on crank generator similar to the original built-in one (see photo in the Gallery, below), but they generated 1/4 the power initially hoped, and less than a thousand were produced. A pull-string generator was also designed by Potenco[37] but never mass-produced.
49. External power options include 110–240 Volt AC as well as input from an external solar panel.[38] Solar is the predominant alternate power source for schools using XOs.

Major builds

XO 1 has major builds indicated by build numbers or less-than-one increments of the version number. The changes made in each build are to be documented in this section. Other versions (OLPC XO-3) are documented in other articles.

The hardware specifications that were different in older versions of the XO-1 are listed below.

1. XO-1[edit]
2. XO prototype, displayed in 2005.
3. Power option: built-in hand-crank generator.
4. XO-1 beta. Released in early 2007.
5. Power option: separate hand-crank generator.
6. XO-1. Released in late 2007. as of November 2007 are:[39]
7. Power option: solar panel.
8. XO 1.5. Released in early 2010.
9. Via/x86 CPU 4.5 W
10. Fewer physical parts
11. Lower power consumption
12. Power option: solar panel.
13. XO 1.75. Released in TBD late 2011. Slated to have:
14. 2 Watt ARM CPU
15. Fewer physical parts, 40% lower power consumption.
16. Power option: solar panel.[40]
17. XO 2[edit]
18. XO 2. Previously scheduled for release in 2010, canceled in favor of XO 3. Price target $75. Elegant, lighter, folding dual touch-screen design (See photo in the Gallery section, below). Hardware would have been open-source and sold by various manufacturers. Choice of OS (Windows XP or Linux) outside of the US. $150 price target in the USA includes 2 computers, one donated.[41]
19. XO 3[edit]
20. XO 3 Canceled in favor of the XO-4
21. Scheduled for release in late 2012.
22. One solid color multi-touch screen design. For details see OLPC XO-3.
23. Power option: solar panel in cover or carrying case.
24. XO 4[edit]
25. The XO 4 is a refresh of the XO 1 to 1.75 with a later ARM CPU and an optional touch screen. This model will not be available for consumer sales. There is a mini HDMI port to allow connecting to a display.[42]
26. XO Tablet[edit]
27. The XO Tablet was designed by third-party Vivitar, rather than OLPC, and based on the Android platform[citation needed] whereas all previous XO models were based on Sugar running on top of Fedora.

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 color displays with an appearance similar to electronic paper.

The display is the most expensive component in most laptops. In April 2005, Negroponte hired Mary Lou Jepsen—who was interviewing to join the Media Arts and Sciences faculty at the MIT Media Lab in September 2008—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. In the OLPC XO-1, the screen is estimated to be the second most expensive component (after the CPU and chipset).

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 each pixel.[dubious – discuss] This grating pattern is stamped using the same technology used to make DVDs. The grating splits the light from the white backlight into a spectrum. The red, green and blue components are diffracted into the correct positions to illuminate the corresponding pixel with R, G or B. 

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. Most LCD screens use cold cathode fluorescent lamp backlights which are fragile, difficult or impossible to repair, require a high voltage power supply, are relatively power-hungry, and account for 50% of the screens' cost (sometimes 60%). The LED backlight in the XO-1 is easily replaceable, rugged, and inexpensive.

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.