This book emerged from lecture notes of a course taught in the second year to students of Computer Science at the Federal Institute of Tech­ nology, Zurich. The topic of hardware design plays a relatively minor role in Compu­ ter Science curricula at many universities. Most courses concentrate on the various aspects of theory, software, and of information sys­ tems. Students therefore obtain few opportunities to deal with con­ crete engineering problems and physical devices. We consider this as rather unfortunate, particularly for technical universities. As a result, we observe a growing gap between interest in and understanding of design issues involving not only software but also hardware and inter­ faces. This is regrettable at a time when new and advanced solutions to many problems are often crucially influenced by recent hardware de­ velopments, at a time when the engineer needs to be competent in both software and hardware issues in order to fmd an optimally inte­ grated, competitive solution. It turns out that the hesitation of many students in Computer Science to take an active interest in hardware - his or her daily tool! - does not only stem from a preference of "clean", abstract concepts with a corre­ sponding distaste for dealing with concrete components, construction techniques, and the "dirty" realities inflicted by nature, but also stems from the lack of a bridge between the two realms.