Written to meet the objectives of the BTEC Unit Microelectronic Systems U86/333 which are specified for a single unit at NIII level, this is one of three volumes which aim to cover all aspects of the BTEC Unit from a theoretical and practical point of view, providing material for both classroom activities and self-supported study. The book's intention is to extend the student's understanding of the operation of microprocessor-based systems by examining the data sheets and typical use of common integrated circuits found in microcomputers. It also aims to develop the techniques of Assembly Language programming introduced in the previous volume, with particular reference to the special requirements of interrupt-driven systems. Practical aspects of microcomputers are covered in detail. As well as a certain basic knowledge, the book assumes in the student a full understanding of binary numbers, hexadecimal numbers and instruction mnemonics.