The performance of microprocessor has been increasing exponentially since its inception in early 1970s. Microprocessors are the workhorses of modern high performance system. The importance of microprocessor and its applications is well known in science and engineering fields. The aim of this book is to deal with microprocessor 8085 architecture and its programming. The details of the architectural design have been dealt in depth. The book is structured to cover all key aspects of microprocessor programming. The topic of timing diagram is discussed at length. It can be of very much help to students, scientists, researcher and engineer etc. for learning assembly language programming. A large number of assembly programs have been developed and explained to explore the strength of low level programming. All programs can be executed on any 8085 microprocessor kit or any readily available simulator.