As promised the source code to SDIOS06 was released under the GPL.

SDIOS06 is a toy operating system developed during the practical course SDI (System Design and Implementation) at the Systems Architecture Group of the University of Karlsruhe. It was designed and written by Timo Bingmann, Matthias Braun, Torsten Geiger and Andreas Mähler. Two games were ported to a custom SDL implementation using the VMware "hard"-ware: SDLjump and SuperTux. For more information and screenshots see my blog entry 20060727-SDI-Demo.

The source code archive was published on the L4Ka.org page: http://www.l4ka.org/projects/SDIOS06/

A local copy of the source archive (7.4 MB) is available as well. The README file contains a great deal of information about SDIOS06's design and modules. The complete source code can be browsed on the web.

To make demonstration as easy as possible a ready-to-run binary vmware image (3.8 MB) can be downloaded. The image contains SDIOS06 installed on a virtual vmware disk image. The VMware image can be run using the free VMware Player.

Sdlfractal is a port of a simple little fractal generator which I wrote some five years ago. It is not supposed to replace wonderful tools like xfractint so it is very simple and not very fast. The main goal of this project was to learn SDL and it turned out that fltk was also required. The main construction is an SDL surface extended by a canvas class which simulates a high-resolution coordinate system. On this coordinate system the fractals can be drawn.

To control fractal parameters the generator displays a second window using the fltk engine. From this dialog the currently displayed fractal and it's parameters can be changed. This requires a dual engine event loop in the program.

By dragging the mouse on the drawing canvas you can zoom into all fractals. If fractal drawing takes too long (and nothing is shown), then just click the canvas and the generator will stop.

The fractal generator can also save high-resolution PNG files. The following images are some examples created by the fractal generator.

The source code to sdlfractal 0.1 can be downloaded in a tar.bz2 archive (121 KB). It is also browsable on the web.

Sdlfractal was designed to the portable to Win32 using SDL and fltk compiled with MinGW. A compiled version which should run out of the box on most windows. Download the zip archive (267 KB) containing the executable.

MD5sums of the source and binary archives:
538da60a5ef2d427fbb901d6080e631e sdlfractal-0.1.tar.bz2
5bab1ccb93e170f5c42d995a6761ca7a sdlfractal-0.1-win32.zip

This section of the mandelbrot fractal is so beautiful that it is my current wallpaper. It can be downloaded at 800x600 (242 KB), 1024x768 (372 KB) or 1280x960 (552 KB).

Today was the final demo presentation day for the practical course SDI (System Design and Implementation) at the Systems Architecture Group of the University of Karlsruhe. Goal of the course was to implement a simple operating system on top of the L4 microkernel, which is developed at the Group.

Our practical course group was one of the two groups to demonstrate a working system on the last day of the semester. The presented operating system contained following basic components:

• An initial root task,
• a pager (memory server and task server combined) creating virtual address spaces,
• a root name server for servers to register their facilities,
• a minix file system server which extends the name space to files,
• a (virtual) console server reading keyboard input and writing to the screen buffer,
• and a limited shell with two utility programs: ls and cat.

Furthermore we utilized the VMWare video "card" to enable graphics output. The "hardware" is well documented in the source code to the X11 video driver contributed by VMWare.

The frame buffer and keyboard input was linked up to a ported SDL implementation. After adding a lot of POSIX library function calls like fopen, opendir and getenv, it was possible to compile our favourite games: SDLjump and SuperTux. Both run very well on our operating system from scratch project.

Some screenshots of the shell, sdijump and supertux are available. In future the whole source code and compiled binary images may become available

A big thank you to my friends Matthias Braun, Torsten Geiger and Andreas Mähler, who made this practical work possible and especially fun!