Synopsis The present book has been thoroughly revised and 5 new chapters have been added to widen the scope of the book. The new chapters are : D/A and A/D Converters, Semiconductor Memories, Programmable Logic Devices, Fundamentals of Microprocessors, Digital System Design using VHDL.  An important feature of this book is as 5-V power supply, 50 Hz pulse generator, the cross-Nand switch debouncer, a digital clock with a seven segment LED display for displaying hours, minutes and seconds.