THE A+ COURSE INTRODUCTION This book has been developed to reach two very specific goals.

First of all, it was written to provide you with fundamental information to become a more informed computer user. If you diligently go through the material in these texts, you will be enlightened about computers and how they operate. The second goal for this book is to assist you in passing the CompTIA A+ certificating exam. Its no longer enough to say that you know about computers. Companies expect that you can back up your words with one or both of two things technical certification and work experience. CompTIA certification covers a baseline of Technical knowledge focusing on two areas basic computer Hardware concepts and basic computer Operating System Concepts.

Why be Certified?
With a choice between two people who are transitioning into the technical environment and have no hands-on experience with computers or networking, the person who has taken the time to study and pass the examination will have advantage over the person without certification. Dont misunderstand; in the technical arena, experience matters. Certification by every authority in this industry wont cause you to be chosen over a candidate who has over ten years of serious experience. However, adding certification credentials to your resume makes sense even for those who have a great deal of experience.

The CompTIA Certification Suite

CompTIA offers three certification exams dealings with computing Technology, as follows; A+ The original CompTIA exam focuses on basic Hardware and Software knowledge N+ Internet + The Second exam offered by CompTIA focuses on the basics of Computer Networking, dealing with both hardware and software information The most recent CompTIA exam focuses on the Internet technology, providing a high level overview of Internet history and Technology from Hardware, Software and business perspectives

The A+ Examination
The A+ plus exams consists of two separate exams; Core Hardware examination: This covers the hardware portion of the course. A+ OS Technologies exam: This focuses on software (Dos and Windows). This test can be taken one right after the other or they can be scheduled separately. But between 90 days of each other. Failure to do so results in writing both papers again even if you pass one already.

LESSON 1 INTRODUCTION TO THE COMPUTER SYSTEM The computer can be described as an electronic device that accepts data, processes data, stores data and brings it out as information. The computer System can be subdivided into two main categories, i, Hardware ii, Software HARDWARE The physical components of the computer that can be felt and touched are called the computer Hardware. From the definition of the computer above, the computer system has the ability to accept data. A data is the raw instructions given to the computer. There are certain hardware devices dedicated to receive or accept data into the computer system, these are called Input devices. Information is a processed data. There are certain Hardware devices also dedicated to bring out information from the computer system, and these are also called the Output devices. These input and output devices (peripherals) come together with some other devices to make up the computer system.

Input Devices
Input devices are devices which actually helps users to put in data into the computer system by converting user understandable data into a format the computer understands for processing. Examples of such devices are; i, Keyboard ii, Scanner iii, Digital camera iv, Web camera v, Microphone

Output Devices
These are also devices that help users to retrieve or bring out information from the computer by converting the processed data to a meaningful format that users can understand. Examples of such devices are,

i, Monitor ii, Printer iii, Speakers iv, Projectors

Pointing Devices
These devices actually do not input nor output, but rather makes the use of the computer very easy and faster. Examples of such devices are, i, Mouse ii, Touch Pad iii, Light Pen iv, Track Ball

Storage Devices
These are devices that store data within the computer system. Computer Storage Devices can be classified into two main groups, Primary and Secondary data storage devices. Primary data Storage: These are storage devices that are always needed in the computer system. The computer will never work without these devices. They are, Read only Memory (ROM) Random access Memory (RAM) Secondary Data Storage: These are storage devices that the computer system can do without e.g. Hard disk drive, Floppy disk, Compact Discs, Pen drives etc. SOFTWARE Hardware devices can never interact with one another without the help of software. Software is a set of instructions or a program that runs the computer system. This software actually tells the hardware devices how to deal with one another and also how to handle data. There are two main types of data that runs the computer system these are i, System Software ii, Application Software. System Software A set of instructions or a program that controls the computer system is called a System Software. There are two main types of system software; Operating system; A set of instruction that provides a user interface, control hardware devices and allow other software to be installed e.g. DOS, Windows, Linux Utilities: Software that works with the Operating system to prevent computer virus infection.. E.g. Anti Virus Application Software: Software designed to perform a specific task. E.g. MS Word, Corel Draw All topics mentioned here will be discussed into details later in this course.

LESSON 2 BASIC ELECTRONICS A computer is described as an electronic device which accepts data, processes it, stores data and brings it out as information. Therefore the subject of computer cannot be raised without the first understanding its source of power. Every computer must have power to function. Electrical impulses are used in a computer to represent the binary number system of 0s and 1s that computers understand. Many people who usually work with computers know barely little about electricity. For safety reasons; (both for the user and the computer) we have to understand some basic facts concerning electricity. After these basics are covered we then look at the physical devices that make up a computer system.

Electricity
At most basic level, electricity can be defined as the movement of charged particles called electrons. Electrons are sub-atomic particles with negative charges. These electrons are moving all around us, all the time, through any substance you can name: water, air, earth even our own bodies. However electrons can be channelled into a stream that flows along a path by creating a passageway on a substance that allows electrons to easily flow through it. This action is commonly referred to as electricity. Generally certain materials allow electricity to pass through and some doesnt. Materials through which electricity can flow are called Conductive materials. Some substances are better at conducting electricity than others. While both non-purified water and metal are good conductors, metals are easier to work with as compared to non-purified water. So in order to channel the flow of electricity from one part to the other a path is created using a metallic wire. The opposite of a conductive material is an Insulative material. Some insulators are so resistive that they essentially block the flow of electrons. Taking advantage of insulative materials, wires that conduct electricity are wrapped in an insulative materials such as; plastic, to prevent shock when handled.

Alternating Current and Direct Current

The first two terms you should be familiar are Alternating Current (AC) and Direct Current (DC). These terms describe the directional flow of electricity.

Alternating Current
Alternating current indicates that the current regularly reverses its direction of flow. AC is well suited for transmitting electrons over long distances. Your homes wiring and outlets distribute this AC power to appliances such as lights, refrigerators, iron televisions and computers.

Direct Current
Direct current means that the flow of current continues in only one direction. DC is used to transfer electrons in very short distances. Because they supply a non alternating continuous flow of current, battery powered circuits are DC circuits. While they generally use AC as a source of supply, the internal circuitry of computers rely on Direct Current.

Electrical Safety

Everyone knows that electricity can be very dangerous. As a computer technician, you will work around electricity much of the time. However the chances of hurting your self or the equipment you are working can be reduced, therefore it is important to know how electricity functions and how to work with it.

Electrical Safety Tips Dont work alone Use only one hand Wear insulative materials Shoes Wear eye protection materials Remove jewellery Dont work when you are tired Do only what you know how to do Dont assume any thing Work only in safe environment