Programming for Children

Edward Mokurai Cherlin Earth Treasury

October 28, 2007

Author

Edward Mokurai Cherlin

גרשון בן יסעף Эдуард Георгеевич Черлын 장영구 / 張永久 法雲默雷 / धर्म�र्म�घशब्दगर्ज�

Experience

Mathematician Peace Corps, Korea Buddhist training,

Japan, US, UK Self-taught, Computer

Science High-tech market

researcher

Free Software development

Senior Tech Writer Simputer Evangelist MBA Student, Presidio

SOM Founder, Earth Treasury

The Children's Cat's Laptop

Origins

Inspired by Simputer from Bangalore MIT Asian Media Lab MIT $100 Laptop project Spun off as non-profit, One Laptop Per Child Funding from Google, Red Hat, eBay, others Design help from MIT, Google, Red Hat, AMD,

Quanta, Free Software community, others

One Laptop Per Child

Education program, not laptop program Designed to meet stringent requirements of

poor children Not dependent on electric system Usable by illiterates No moving parts Extremely rugged, extremely green

What We Need

For each language Text-to-speech Speech recognition Content For each standard school subject

Domain-specific software; the tools of the trade Free textbooks integrated with software

Content

Schools not on Internet will have local copy of Wikipedia in English and local languages.

Children's books Literature and History Math and Science Selection of other freely licensed materials

Extra Content

Earth Treasury proposes to link schools with laptops, and teach the children how to go into business together.

Genuine Free Market Economics, and how to get it

Business skills Dealing with governments Trade law etc.

Hardware

No moving parts; flash storage 3 USB 2, sound, SD card slot Screen rotates to tablet mode Camera built in; microscope attachment Wireless mesh networking Daylight readable screen, 1200 x 900 Extremely low power

Software

Red Hat Fedora Rawhide 7 Linux Sugar User Interface Activities designed for children Smalltalk, Python, Perl, Forth, other languages SCIM (Smart Common Input Method) Pango and Cairo (Unicode screen and printer

rendering)

Marketing

Quanta requires orders for 5 million units to start manufacturing at $188

$1 profit per unit for OLPC Minimum order, 2006: 1 million units @ $189 Minimum order, 2Q 2007: ¼ million units Minimum order, 4Q 2007: 100 @ $299 Someday, retail.

Hot Prospects

Argentina Brazil Cambodia Ethiopia Libya Mexico

Nigeria Peru Rwanda Thailand Uruguay

Initial Languages

Amharic አማርኛ

Arabic عربي Cambodian ភាសាខ្�រ English French Français Hausa 8َه8ْو:َس

Igbo Kinyarwanda Portuguese Portuguesa Spanish Español

Castellano Thai ภาษาไทย Yorùbá

Linux Localization

Done by any language community Provided to whole community at no cost More languages than Macintosh or

Windows Almost all software has separate .po file

of string data Documentation in man, info, help files

XO Programming Languages

Squeak dialect of Smalltalk provided in UI as eToys

Squeak includes Logo capabilities Python used to create UI and apps Perl for scripting Forth for low-level programming Other languages can be installed:

LISP/Scheme, APL, C, C++, etc.

Open FirmWare

Forth programming language Equivalent of BIOS; created at Sun Press game key while booting, then Esc

(top left) At ok prompt, you can type test-all to test

all of the hardware interfaces More information at

http://wiki.laptop.org/go/Open_Firmware

Sugar UI

XO Collaboration

Activities, Not Apps

Packaged as resource bundle Full screen Sharable Instance per file Instant resume

Building Sugar Activities

http://wiki.laptop.org/go/Sugar Install Sugar on Linux, Mac, or Windows Read the human interaction guidelines Get an overview of the architecture Check out the code snippets library Understanding Sugar code organization Write your own activity

Human Interaction Guidelines

Users are young, inexperienced, international 256M RAM, no swap; write efficient code. Make everything simple and discoverable. Security is vital for the children. Adapt to different screen modes, network

states. Children must be able to recover from errors

easily.

Architecture

See http://wiki.laptop.org/go/API Resources include:

Third-party applications Python scripts Libraries

Code Snippets Library

Icons Toolbar Files Images Audio Processes Garbage collection

Code Organization

Launch Sugar, Start Sugar shell, Initialize Libraries, services, and utilities Network Manager User ID and colors Main loop Shutdown http://wiki.laptop.org/go/Understanding_sugar_code

Write Activity

This is normal Python programming, with some Sugar-specific startup and shutdown.

Keep human interface guidelines in mind. Use resources provided as needed. No code bloat.

HelloWorldActivity.py

from sugar.activity import activity import logging import sys, os import gtk class HelloWorldActivity(activity.Activity): def hello(self, widget, data=None): logging.info('Hello World') def __init__(self, handle): print "running activity init", handle activity.Activity.__init__(self, handle) print "activity running"

# Creates the Toolbox.toolbox = activity.ActivityToolbox(self)self.set_toolbox(toolbox)toolbox.show() # Creates a new button with the label "Hello World".self.button = gtk.Button("Hello World")self.button.connect("clicked", self.hello, None)self.set_canvas(self.button) # Display this newly created widget.self.button.show() print "AT END OF THE CLASS"

Sugarizing Non-Python Apps

Very small amount of interface code required to run within Sugar.

See eToys source code for example. Full Sugarizing requires support for

sharing, other Sugar capabilities

References

OLPC http://laptop.org/ OLPC Wiki http://wiki.laptop.org/ On the Wiki, search for Sugar, eToys,

Activities, OFW, Software, Hardware, or any other topic of interest

XO Live CD: http://wiki.laptop.org/go/LiveCd

Earth Treasury http://wiki.laptop.org/go/Earth_Treasury