Systematized information in the field of architecture and internal organization of computer systems. The basic concepts and basic principles of the structural (logical) organization of a modern personal computer (PC) are considered in detail. The principles of operation and design of the main components of the PC are considered: processor, motherboard, memory, disk system, video system. The features of the organization of each of the systems and their connection into a single whole as part of a computer built on the basis of an "open architecture" are shown. The factors that contributed to the success of the "open" PC architecture are indicated. The book contains a large amount of background information useful in everyday practice. Each chapter is equipped with self-test questions.