Changes
SymbOS includes a micro kernel, which takes over the fundamental tasks of an operating system. They are subdivided into the task management, the memory management, the banking management and the messaging.
=== Task management ===
For the task management a combination of pre-emptive and cooperative multitasking has been choosed, which makes different task priorities possible. Pre-emptive means that tasks are interrupted after a certain amount of time by the operating system, in order to share the CPU time with other tasks. Cooperatively means, that a task stops using CPU time by itself. It does it, if it finished its current job or is waiting for a certain event. Because of this combination it is possible to assign priorities. Tasks with a low priority receive CPU time only if all tasks with higher priorities are not currently working.
=== Memory and banking management ===
The banking management makes sure, that the system is able to administer memory with a size of one megabyte even with the fact that the Z80 CPU has only a 16-bit address bus. It makes transparent access to memory and functions placed in other 64 kB banks possible.
=== Messaging ===
The communication between different tasks and the operating system usually does not take place via "Calls", but is done via "Messages". This is necessarily inside a multitasking environment to avoid organisation problems with the stack, global variables and shared system resources.
== Graphical user interface ==
