This work fills a gap in current CS, EE, ECE, and CE curricula not only at the University of Pittsburgh, but throughout the U.S. We create a course and a programming environment to enable teaching senior-level undergraduate students the important area of real-time systems, including the requirements and characteristics of such systems, their internals, and their specification. This course, which will be distributed for any interested instructors through electronic means, will not only have a theoretical part, but also a practical hands-on implementation component. Toward that end, we complement the theoretical part with an implementation environment called DIRETOS: DIrect REal Time Operating System. We achieve with DIRETOS the same capabilities provided by Berkeley's NACHOS (provides a simple operating system on which students build more complex functions) and also by Cornell's HOCA (provides an abstract bare machine, so that students can build their own operating system). We use the NACHOS model combined with the HOCA model, with variations. These variations are based on observations of teaching the class in the last few years and on an informal survey of students and industry.