This book provides the foundation for the development of skills in designing microprocessor-based system. The book contains a comprehensive coverage of Intel Microprocessors 8086, 80186, 80286, 80386, 80486 and Pentium, Motorola Microprocessors 68000, 68010, 68020, 68030, 68040, PowerPC and Intel Microcontrollers 8051, 8096. Floating-point processors have also been taken up. A number of solved examples, practical problems and short questions-answers have been included in each chapter. Historical development of microprocessors has been included in Chapter-1 with introduction to dual core processor. Microcontrollers in Chapter-7 have been given a completely new shape to look like an embedded system approach. The book would serve as a complete text for undergraduate students of Computer Science and Engineering, Electronics and Information Technology.