This book provides a practical way to discover how to use a computer to control external devices via the Com Port, the Parallel Printer Port, or the Parallel Programmable Interface Port. It also introduces students to using a High Level language to read and control these devices via a series of programming exercises using C, and unlike many other texts, introduces hardware and software side by side. The book aims to facilitate independent learning, with numerous practical experiments and programming exercises. Therefore, professionals and enthusiasts will also find this text an ideal way of getting up and running in this important area of microelectronics. Computer Interfacing is designed for a student audience ranging from BTEC National Electronics to first year degree modules. In particular the content has been structured to follow the Microprocessor Systems set unit in the new BTEC Higher National scheme. George Smith brings to bear 16 years of lecturing experience in this highly practical book.