Preface Ever since the 1950s when computers saw their debut in markets all over the world inter est in information technology IT has seen a steady rise The core that supports this tech nology is a semiconductor known as the CPU or central processing unit Since the start of the 21st century advancements in circuit design theory and manufacturing technology have led to rapid progress in both processing speed and chip size allowing us to embed them in most of the electronics we use on a daily basis In addition to personal computers smart phones and tablets you’ll even find CPUs in things like air conditioners refrigerators wash ing machines and other major appliances just to name a few It’s worth noting that the CPUs found in modern PCs are extremely powerful and many of their applications are outside the scope of this book We also will not delve into computer architecture which has had a research boom in recent years Instead I think that the best way to give insight into what CPUs are and by extension how programs work is to go back and analyze how the first CPUs worked and examine the concepts and principles by which they were designed Let me share an allegory with you It’s been quite some time since we first started taking automobiles for granted in our daily lives but despite their ubiquity very few people today can explain how an engine works or how the energy generated by the engine gets translated into forward momentum for the car In the 1950s you had to answer engine design questions on your driver’s license examination but no such questions remain in today’s tests Essentially this means that to learn things about the internals of a car engine today you really have to be an incredibly curious person In that vein my wish is that this book will not only act as a platform to teach readers a range of different topics but also to sate their curiosity on the subject by having them learn some of the deeper principles of the CPUs that have so nonchalantly permeated our daily lives In regards to the publication of this book I would like to thank Sawako Sawada of Office sawa who thought up the fun story and Takashi Tonagi for the illustration work Michio shibuya November 2014
