To that end, we will show you how the MPU is structured, how you communicate with the MPU (its language), and how the MPU communicates with you and the system under its control. Because of that interrelationship, a course on microprocessors is not complete without a through discussion of how the MPU interfaces to its support devices and the outside world. Like the brain in your body, the MPU needs support from many peripheral devices to maintain the system. This is the decision maker, or brain, of the computer. The Microprocessors course is designed to teach you the fundamentals of the microprocessor unit (MPU), or as it is also known, the central processor unit (CPU). "6800" has been added to the book's title to reflect that this book is about the 6800 CPU- not any others CPUs.
This 6800 (and later 6808) CPU-based microprocessor training system went through several iterations over the years- this book is for one of the later versions of the trainer. This book is combination of two earlier books for the Heathkit ET-3400.