Electronic Products Word of the Week: Real Time
What is real time?
BY LEN SCHIEFER, Chief Copy Editor
Simply put, “real time” means “right now.” That being said, in the world of computers, the term is a bit more complicated. A real-time system is, according to Joel Aron, writing in IBM Systems Journal in 1967, “any information processing system which has to respond to externally generated input stimuli within a finite and specified period.”[1] Merriam-Webster quotes R. H. March when it defines the term as “the actual time during which something takes place To quote a recent Electronic Products article, contrasting a real-time operating system (RTOS) with a general-purpose operating system (GPOS). An RTOS, “for instance . . . could run into problems if it maintained the symmetric multiprocessing organization of the PC. In single-core systems, it’s possible to use relatively straightforward techniques to make sure that all of the tasks in a given set will be able to meet their deadlines. However, in an SMP system, with multiple processing units from which to choose, task scheduling can become a rather challenging exercise in logistics.”[3] In the world of real time, deadlines are paramount because real time means that there is no delay. References 1. Quoted in www.control.lth.se/media/Education/DoctorateProgram/2012/HistoryOfControl/Yang-RealTimeSystems-slides.pdf
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