For an introduction to digital systems in two- and four-year programs in technology, engineering, and computer science. While a background in basic electronics is helpful, the majority of the material requires no electronics training.The authors use a block diagram approach to basic logic operations, to enable students to have a firm understanding of logic principles before they study the electrical characteristics of the logic ICs. For each new device or circuit, the authors describe the principle of the operation, give thorough examples, and then show its actual application. Finally, the modern HDL representation is presented.