This foundational book by Dr. Ziyad Al-Qadi offers a deep dive into the influential 8085 microprocessor. Published in 2005, it meticulously details the 8085's architecture, its complete instruction set, and the fundamentals of assembly language programming. It serves as an essential resource for students and engineers in electronics and computer engineering, covering topics like internal registers, addressing modes, and I/O operations. This first part establishes a solid groundwork for understanding microprocessor principles and hands-on programming techniques, paving the way for more advanced studies in the field.