Table of contents : Content: What is a system? Counting systems Types of gate Combining gates to create new functions Digital circuit design to meet given practical 'real-life' situations Simplification of Boolean expressions Karnaugh maps Logic families -- TTL and CMOS Interfacing Combinational and sequential logic RS bistable D-type, JK and master-slave bistables Asynchronus counters Ring and twisted counters Registers Other digital devices Practical methods of building circuits Transmission of digital data Transmission formats and methods Fault-finding and test equipment Further reading Glossary Index.