Karma/Specifications

Introduction

Two main goals should be kept in mind when creating Karma lessons:

1. they should be easy to adapt
2. they should run on as much hardware as possibe with OLPC's XO-1 laptop representing the baseline

General Notes

Hardware constraints

Since a large percentage (if not the majority) of Karma users are envisioned to be using OLPC XO-1 laptops, netbooks, older hardware or generally relatively slow systems there are several performance constraints that need to be taken into account when designing Karma lessons.

• CPU/Memory: The baseline regarding available performance is the XO-1 laptop which comes with an AMD Geode LX 433MHz CPU and 256MB RAM (full specifications). This limits the use of high-resolution multimedia, animations and videos to some degree.
• Display: Karma lessons should work well on displays with a resolution of 1024*768 (whereby a part of the display may be taken up by browser UI elements!).
• Mass storage: Since especially the XO-1 laptop only has very limited local mass storage (1GB) lessons should be kept reasonably small.
• Connectivity: Karma lessons must not assume constant connectivity with a locally (e.g. XS) or globally available server. Support for storing data locally will be provided by Karma.

Accessibility

Follow best practices for accessibility (e.g. example of a checklist), especially with regard to colorblindness.

Animations

• Format(s): TBD
• Recommended tools: TBD
• Notes: TBD

The Karma animations are created using JavScript and the Karma plugin. At this moment we haven't defined a mechanism to "export" (and "import") one animation. But copying and pasting the code (of the animation) will be enough in most cases.

Images

• Format(s): JPEG, PNG, SVG (Note 1, 2 and 3)
• Recommended tools: Inkscape, GIMP, Adobe Illustrator (non-free), CorelDRAW (non-free)
• Max. resolution: 1200*900 px
• Notes:

1. To handle SVG files will be necessary to create a parser svg2canvas in order to introduce them as objects inside canvas element.
2. Animated SVG content will be hard to reproduce using canvas.
3. SVG animations seems slow under the XO-1 (Tested with RaphaelJS and Browse)

Sound

• Format(s): OGG Vorbis
• Bit rate: TBD
• Max. size per lesson: 3~4MB
• Recommended tools: Audacity
• Notes: TBD

Video

• Format(s): TBD
• Recommended tools: TBD
• Notes: TBD
• ...