This textbook provides an introduction to microprocessors and computers for first and second year undergraduate and diploma students. It is a thoroughly revised and updated new edition with coverage of the Motorola MC68000 and MC68HC11 and the Acora ARM processors. The book takes an interpreted approach to computers and microprocessor with equal emphasis on components and systems, applications and design. The dual role of the computer as a computing machine and an electronic component is acknowledged and the rationale behind the design of computers is explained together with ways in which they function.