Computers may appear complex on the surface, but at their core they are built from a small set of simple ideas. Every instruction executed, every calculation performed, and every decision made inside a computer ultimately comes down to basic logic circuits working together in an organized way. This book is written to uncover that simplicity and make CPU design understandable to anyone with curiosity and determination.
This book takes a bottom-up approach. Instead of starting with abstract theory, you will begin with fundamental logic gates—AND, OR, NOT, NAND, and XOR—and gradually combine them into more meaningful building blocks such as adders, registers, and basic control logic. Step by step, these components come together to form a working simple CPU.
To make learning accessible and practical, the entire process is carried out using a CPU emulator. The emulator allows you to design, test, and debug circuits without needing physical hardware. You can experiment freely, observe signal behavior in real time, and immediately see how small design changes affect the overall system. This hands-on approach helps bridge the gap between theory and real-world digital systems.
This book is intended for:
Beginners in digital electronics and computer architecture
Students who want a clear, practical understanding of how CPUs work internally
Hobbyists and self-learners interested in low-level computing
Anyone who wants to move beyond using computers to understanding how they are built
By the end of this book, you will not only know what a CPU does, but how it is constructed, how it makes decisions, and how simple logic can scale into powerful computing systems. Most importantly, you will gain the confidence to explore more advanced designs and architectures on your own.