Rtos?

Hi,

In doing research on embedded software, I'm starting to see the term Real-Time Operating System (RTOS) a lot. They usually mention VxWorks or PSOS.

Can someone give me a brief run down of what a RTOS is? how is it different than say Windows or Linux?

Any help or links to resources would be greatly appreciated..

Dan

Hi
A real-time operating system has to perform its function within a given time frame "real-time". An example of such a system is an engine management system. It has to calculate the throttle position, fuel flow rate etc before it can actuate valve and spark plugs in the engine. A RTOS must perform all the calculations before the data is needed. In a windows type evironment (Non-deterministic) it doesn't really matter if you have to wait for a few extra seconds for a task to be completed.

Generally an RTOS performs functions to allow concurrency (multiple tasks at a time) Time scheduling for different tasks and task implimentation with minimal knowledge of the actual system. Similar to Windows.

Many modern RTOS's are written in C or Java and are exceptionally reliable for use in life critical situations. Check out http://www.mentor.com/embedded/brochuresvrtx.html for info on the VRTX RTos

Hope this helps

NormRC