Computer Systems Architecture, by Rob Williams, presents an incremental look at networked computer systems starting with digital logic and hardware, moving through the layers of software and leading to an introduction of networking and operating systems. Its practical, modern approach draws upon areas of student interest and experience (the Internet, Pentium processors, GUIs, mobile communications) to stimulate the reader's enthusiasm for the subject. Throughout, the author emphasizes how software performance can be dependent on hardware features. Practical exercises demonstrate this aspect of hardware/software interaction. Computer Systems Architecture is meant as a 1st year introduction to the subject for students in Computer Science and related courses.