Introduction
Two main goals should be kept in mind when creating Karma lessons:
- they should be easy to adapt
- 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
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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:
- To handle SVG files will be necessary to create a parser svg2canvas in order to introduce them as objects inside canvas element.
- Animated SVG content will be hard to reproduce using canvas.
- 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
- ...