Abstract :
What is a `real time´ system? Does it need to be real fast? Are we talking microseconds or hours? What happens if we `get it wrong´? These are all good questions. However, real time systems can be defined. They are systems that handle asynchronous events in a timely and deterministic manner. What does this mean? Well, timely means that the controlling system is able to keep up with the process that is being controlled; determinism is a key attribute that allows the state of the controlling process to be precisely defined-no matter what input conditions prevail. The author discusses DOS operating system and its implications for real time systems