... learning about what is going on “under the hood” of a computer system. Our aim is to explain the important and enduring concepts underlying all computer systems, and to show you the concrete ways that ... 15-213: Introduction to Computer Systems. The course has been taught every semester since then, each time to about 150 students, mostly sophomores in computer science and computer engineering. ... In fact, we believe that the only way to learn systems is to do systems, either working concrete problems, or writing and running programs on real systems. This theme pervades the entire book....