From the time when Charles Babbage first started construction of his difference engine through the construction of the Colossus computing machine and into the electronic micro circuit era the computer processing machine has undergone rapid and astounding development. From machines capable of carrying out a few calculations each minute the modern microprocessor is able to perform calculations in less than a second that the early machines would have taken over a thousand years to complete. This book winds back the clock almost 50 years to the dawn of the electronic microprocessor to show how a microprocessor can be built using only transistors. Includes all circuit diagrams and explanations on how they work through to the development of a fully functional unit that is capable of executing programs while displaying the inner workings of this amazing device. The reader can either follow the construction to build their own processor or just read through the process. Either way the information contained in this book should provide a source of interest for those who really want to understand how the processor at the core of almost every electronic system actually works.