Introduction to Computers
This chapter begins by constructing a set of primitive procedures, and examines how to perform operations such as adding two numbers or transferring two numbers from one memory store to another. It examines a level, to the next order of complexity, and uses the instructions to produce operations like multiply and so on. The result of acting on a pair of variables with an operator such as AND is often summarized in a "truth table". The chapter explores the idea that the clerk knows how to get the information out of the filing system. Computers are the complicated objects that simplifying ideas like this are usually necessary, and good design is essential if people want to avoid getting completely lost in details. The chapter explores the impatient among people might think too much detail, but it is a perfect model for communicating the essentials of what a computer does, and is hence worth spending some time on.