1.1 Overview of Computer Systems

This section provides a top-level view of the different components in a computer system. You will also obtain a basic understanding of how a computer works using its sub-components.

Reading Sequence: 1.1.1 Components of a Computer System. Learning Goal: To gain a general overview of computer system components, the hardware system, the software system, and the network system. Parsons/Oja, Chapter 1-Section B. Learning Goal: Knowledge of the basic computer operations (input, processing, and output). Questions for your reading: Upon completing this reading, test your understanding by trying to answer the following questions: -What different kinds of computers are available? -How can you add optional equipment to a computer? -Why is it useful for computers to be able to communicate with each other? -Why do you think devices like monitors, printers, and keyboards are called "peripherals"? Optional: Parsons/Oja, Chapter 1-Lab: "Operating a Personal Computer". Learning Goal: Knowledge of the process involved in turning on a computer and having it run a program.

                                    

Assessment: Multiple-Choice Quiz 1

-

1.1.1 Components of a Computer System

• Hardware System

• Software System—Operating System Software and Application Software

• Network System

A computer is an electronic machine that performs input, processing, storing, and output according to programmed instructions to carry out specific tasks. Formerly, computers were used primarily to do arithmetic computations, hence the term, computer. Consider the primitive form of a computer, a calculator. You input the numbers and the arithmetic operation you need the calculator to perform, for example, “3+5=”, and then the calculator processes the arithmetic expression by adding 3 and 5, stores the result of 8, and outputs the result onto the display area.

The modern computer operates in a similar fashion. Input to a computer can be sent through the keyboard or mouse. The computer then processes the input, stores the result, and displays the result via the monitor, speaker, printer, or other output devices. For example, when you request for a web page by typing in its URL (Uniform Resource Locator), "http://www.icarnegie.com", the computer processes your input by fetching the requested page over the Internet. It then displays the fetched page on your monitor as output.

In general, a computer system can be decomposed into the hardware system, the software system, and the network system. Each of these subsystems will be discussed in more detail in subsequent units of this course. The figure below illustrates the major subsystems in a computer system with some examples.

Figure 1 Components of a computer system

Let us now look at each subsystem and their main functionality.

Hardware System

The hardware system consists of external and internal physical components that enable a computer to accept input, process the input, store data, and produce outputs. Each of the hardware components will be discussed in more detail in Unit 2. Hardware Systems.

The figures below show some external hardware components of a computer.

Figure 2 Hardware components

The diagram below indicates the hardware components inside the system unit. Each of these components plays an essential role in the operation of a computer system.

Figure 3 Components inside the system unit

Hardware components provide the physical interface to a computer system. However, they cannot function without instructions to operate them. These instructions are software programs.