Mechanical and automotive engineers cannot escape the impact of the microprocessor. Fortunately, the microprocessor and its related parts can be well understood without an extensive knowledge of electronics. The functions of the parts of a microcomputer and their interactions are presented. The microprocessor, clock, memory, and input/output section are defined and discussed. The relationship of binary and hexadecimal numbers to machine language and assembly language programming is made clear. This information will enable the engineer to better understand papers, presentations, and sales literature related to microcomputers.