Working as an engineer with advanced weapon systems for more than 25 years, it was crucial to understand the fundamentals of digital systems design development methods and combinational logic circuits. Whether as a technician or as an engineer, these fundamentals are the basics of engineering and are essential in interpreting logic gate functionality. The intent of this book is to provide much more information than most commercial engineering references currently offer. Chapter 1, Latch and Flip Flop Circuits, discusses fundamental operations of NAND gate latch, NOR gate latch, gated S-C latch, gated D latch, four-bit bistable latch, D-type flip flop, JK-type flip flop, and master slave JK-type flip flop circuits. Chapter 2, Characteristics of Digital Circuits, provides a brief introduction to circuit characteristics. This chapter discusses RC time constants, electrical and dynamic behavior of circuits, timing considerations, and data storage and transfer devices. The chapter review and answer sections contain an extensive number of questions that afford comprehensive insights into obtaining the answers. This book will be an extremely valuable asset for technical and engineering students studying digital system design.