Computer Science Programming Basics in Ruby

2.2 Basic Nomenclature and Components of a Computer System

It may be argued that this brief introduction to hardware is unnecessary. The computer has become a utilitarian device, to be used by people who are nontechnical—the same way that a car can be used by all people, without any need to understand the workings of the engine, the various support systems, and the energy management of the car. This is true, but only partially.

Consider a hybrid car, such as the Toyota Prius. It is designed to be just like any other car: drivable without the intricate understanding needed to grasp the concept of the synergy drive of a car where multiple modes of propulsion cooperate to optimize the energy usage of this essentially electric car. However, the actual energy consumption differs between drivers. Those who understand the working of this car will get better energy efficiency than the casual driver—in our experience sometimes as high as a 15% difference.

We argue that the same concept is true for software. Understanding the underlying machinery (the computer system) enables more efficient software development. This may not be important for small tasks, but it may be crucial for very large ones.

A digital computer—and we limit ourselves to these only—is a device that has three main parts: at least one processing unit, called the central processing unit or CPU, at least one memory unit, and a control unit. A computer system has, in addition to a computer, a set of peripheral devices that ...