A book by well-known American experts discusses the machine organization and basic instruction set of the 80286 microprocessor. The manifestation of new capabilities of the 80286 processor in the virtual address mode is shown, which primarily concerns hardware support for such functions of the operating system as memory segmentation, protection, interrupt processing, switching from one task to another, etc. The register model and instruction system of the 80287 arithmetic coprocessor, as well as its features interaction with the central processor. For design engineers of microprocessor systems.