The present book is comprehensive study of Digital Logic Design. It is designed for the students, teachers and research scholars of Computer science and Engineering, Information Technology, Electronics and Communication Engineering, Electrical Engineering, BCA, B.Sc., M.Sc., IETE and AMIE. It provides a new paradigm for the teaching of the subject. The entire book is divided into nine chapters. The topics covered in the book are - the binary codes suitable for representing information in digital systems; the basic and universal gates; the formal procedure for analysis and design of combinational circuits; the outlines of flip-flop like S-R flip-flop, D-flip-flop, J-K Flip Flop, master slave J K flip flop; the various types of registers viz SISO, SIPO, PISO, PIPO; outline of logic families such as DTL, RTL, TTL, MOS, CMOS and I2L; the RAM, ROM, PLD PLA, PAL, RTL, ASM; formal procedures of analysis and design for asynchronous sequential circuits and the brief history of analog and digital computer