The book is designed for an undergraduate course on 16-bit microprocessor and Pentium. The Intel 8086 microprocessor is one of the most popular and appears in several versions of the IBM Personal Computer. Intel's 80x86 family of microprocessors is the most widely used architecture in modern microcomputer systems. This book has been written for beginners. It begins by explaining the fundamentals of assembly programming and then describes the essential details of the 8086 chip. The book illustrates number of different programs for better understanding. This book will be very useful for engineering and science students in the branches of Electrical, Instrumentation, Electronics, IT, Computer Science, Telecommunication and allied branches. Book provides detailed coverage of the other microprocessors in the 80x86 family: 80286, 80386, 80486.