Supposedly a unit on operating systems, but has been found to be somewhat lacking in content. The beginning of the unit is used as an excuse to teach C (this may changed with the new C programming unit). There is a project of varying difficultly (in 2003 it was writing a portable shell, it has gotten harder since then) which is in C.
This serves as many student's introduction to the C programming language. It unfortunately does not serve as their introduction into the debugging tools that would make it otherwise bearable.
[http://web.csse.uwa.edu.au/undergraduate/outlines/230.205.html Handbook Entry]