This text is intended for microprocessor courses at the undergraduate level in technology engineering and computer science. Now in its third edition it provides a comprehensive treatment of the microprocessor covering both hardware and software based on the Z80 microprocessor family.This edition preserves the focus of the earlier editions and includes the following changes: Chapters have been revised to include the most recent technological changes in 32- and 64-bit microprocessors and 8-bit microcontrollers. Several illustrative programs have been added throughout the text. Complete data sheets for the LM 135 temperature sensor and LCD panel and a complete list of Z80 instructions with machine cycles T-states and flags are included in the Appendixes. Appendix G which contains answers to selected questions has been added.