This book employs a bottom-up educational approach with an overall educational objective of allowing students to discover how the computer interacts with its environment through learning basic computer architecture, assembly language programming, as well as through an introduction to interfacing. Developed around the Freescale 9S12, this book describes both the general processes and the specific details involved in microcomputer simulation. In particular, detailed case studies are used to illustrate fundamental concepts, and laboratory assignments are provided.