Gawharshad Institute of Higher Education Faculty of Computer Science Information Technology Essentials Chapter # 1 2017 Welcome Welcome to the Information Technology (IT) Essentials course. The goal of this course is to introduce you to computer hardware and software, as well as operating systems, networking concepts, mobile devices, IT security, and troubleshooting. These online course materials will assist you in developing the skills necessary to work as a technician in the field of IT. The specific skills covered in each chapter are described at the start of each chapter. You can use your smart phone, tablet, laptop, or desktop to access the course, participate in discussions with your instructor, view your grades, read or review text, and test your understanding using interactive media. You can also take quizzes and exams on your mobile device. Download Cisco Packet Tracer Mobile to complete Packet Tracer Activities found throughout the course. Education and Certifications In this course, you will gain the specialized technical skills needed to install, maintain, secure, and repair computers. Earning an industry-standard certification provides confidence and increases your opportunities in IT. This course will prepare you to take the CompTIA A+ Certification exams. This course is only an introduction into the world of IT. A technician can continue to study and earn the following certifications: CCNA - Cisco Certified Networking Associate CCNP - Cisco Certified Networking Professional CCIE - Cisco Certified Internetworking Expert CISSP - Certified Information Systems Security Professional MCP - Microsoft Certified Professional MCSA - Microsoft Certified Systems Administrator MCSE - Microsoft Certified Systems Engineer Network+ - CompTIA Network Certification Linux+ - CompTIA Linux Certification You can use IT certifications as credits for some university and college degrees in areas such as computer science and telecommunications. Chapter 1: Introduction to the Personal Computer A computer is an electronic machine that performs calculations based on a set of instructions. The first computers were huge, room-sized machines that took teams of people to build, manage, and maintain. The computer systems of today are exponentially faster and only a fraction of the size of those original computers. A computer system consists of hardware and software components. Hardware is the physical equipment. It includes the case, keyboard, monitor, cables, storage drives, speakers, and printers. Software includes the operating system and programs. The operating system manages computer operations such as identifying, accessing, and processing information. Programs or applications perform different functions. Programs vary widely depending on the type of information that is accessed or generated. For example, instructions for balancing a check book are different from instructions for simulating a virtual reality world on the Internet. Cases The case of a desktop computer houses the internal components such as the power supply, motherboard, central processing unit (CPU), memory, disk drives, and assorted adapter cards. Cases are typically made of plastic, steel, or aluminum and provide the framework to support, protect, and cool the internal components. A device form factor refers to its physical design and look. Desktop computers are available in a variety of form factors including: Horizontal case – These were popular with early computer systems. The computer case was horizontally oriented on the user desk with the monitor positioned on top. This form factor is no longer popular. Power Supplies Electricity from wall outlets is provided in alternating current (AC). However, all components inside a computer require direct current (DC) power. To obtain DC power, computers use a power supply, as shown in Figure 1, to convert AC power into a lower voltage DC power. The following describes the various computer desktop power supply form factors that have evolved over time: Advanced Technology (AT) – This is the original power supply for legacy computer systems now considered obsolete. AT Extended (ATX) – This is the updated version of the AT but still considered to be obsolete. ATX12V – This is the most common power supply on the market today. It includes a second motherboard connector to provide dedicated power to the CPU. There are several versions of ATX12V available. EPS12V – This was originally designed for network servers but is now commonly used in high-end desktop models. A power supply includes several different connectors, as shown in Figure 2. These connectors are used to power various internal components such as the motherboard and disk drives. The connectors are “keyed” which means that they are designed to be inserted in only one orientation. The table in Figure 3 describes common power supply connectors. The different connectors also provide different voltages. The most common voltages supplied are 3.3 volts, 5 volts, and 12 volts. The 3.3- and 5-volts are typically used by digital circuits, while the 12-volt is used to run motors in disk drives and fans. The table in Figure 4 highlights the different voltages provided by a power supply. Power supplies can also be single rail, dual rail, or multi rail. A rail is the printed circuit board (PCB) inside the power supply to which the external cables are connected. A single rail has all of the connectors connected to the same PCB while a multi rail PCB has separate PCBs for each connector. A computer can tolerate slight fluctuations in power, but a significant deviation can cause the power supply to fail. Power Supply Wattage Power supply specifications are typically expressed in watts (W). To understand what a watt is, refer to the table in Figure 1 which describes the four basic units of electricity that a computer technician must know. A basic equation, known as Ohm's Law, expresses how voltage is equal to the current multiplied by the resistance: V = IR. In an electrical system, power is equal to the voltage multiplied by the current: P = VI. Computers normally use power supplies ranging from 250W to 800W output capacity. However, some computers need 1200W and higher capacity power supplies. When building a computer, select a power supply with sufficient wattage to power all components. Each component inside the computer uses a certain amount of power. Obtain the wattage information from the manufacturer’s documentation. When deciding on a power supply, make sure to choose one that has more than enough power for the current components. A power supply with a higher wattage rating has more capacity; therefore, it can handle more devices. On the back of some power supplies is a small switch called the voltage selector switch, as shown in Figure 2. This switch sets the input voltage to the power supply to either 110V / 115V or 220V / 230V. A power supply with this switch is called a dual voltage power supply. The correct voltage setting is determined by the country where the power supply is used. Setting the voltage switch to the incorrect input voltage could damage the power supply and other parts of your computer. If a power supply does not have this switch, it automatically detects and sets the correct voltage. CAUTION: Do not open a power supply. Electronic capacitors located inside of a power supply, shown in Figure 3, can hold a charge for extended periods of time. For more information about power supplies, click here. Lab - Ohm’s Law In this lab, you will answer questions based on electricity and Ohm’s Law. Lab - Ohm’s Law Motherboards The motherboard, also known as the system board or the main board, is the backbone of the computer. As shown in Figure 1, a motherboard is a printed circuit board (PCB) that contains buses, or electrical pathways, that interconnect electronic components. These components may be soldered directly to the motherboard, or added using sockets, expansion slots, and ports. These are some connections on the motherboard where computer components can be added, as shown in Figure 2: Central Processing Unit (CPU) - This is considered the brain of the computer. Random Access Memory (RAM) - This is a temporary location to store data and applications. Expansion slots - These provide locations to connect additional components. Chipset - This consists of the integrated circuits on the motherboard that control how system hardware interacts with the CPU and motherboard. It also establishes how much memory can be added to a motherboard and the type of connectors on the motherboard. Basic input/output system (BIOS) chip and Unified Extensible Firmware Interface (UEFI) chip - BIOS is used to help boot the computer and manage the flow of data between the hard drive, video card, keyboard, mouse, and more. Recently the BIOS has been enhanced by UEFI. UEFI specifies a different software interface for boot and runtime services but still relies on the traditional BIOS for system configuration, power- on self test (POST), and setup. Figure 3 displays a motherboard with some additional components installed. Most chipsets consist of the following two types: Northbridge – Controls high speed access to the RAM and video card. It also controls the speed at which the CPU communicates with all of the other components in the computer. Video capability is sometimes integrated into the Northbridge. Southbridge – Allows the CPU to communicate with slower speed devices including hard drives, Universal Serial Bus (USB) ports, and expansion slots. Figure 4 illustrates how a motherboard connects various components. The form factor of motherboards pertains to the size and shape of the board. It also describes the physical layout of the different components and devices on the motherboard. There have been many variations of motherboards developed over the years. There are three common motherboard form factors: Advanced Technology eXtended (ATX) - This is the most common motherboard form factor. The ATX case accommodates the integrated I/O ports on the standard ATX motherboard. The ATX power supply connects to the motherboard via a single 20-pin connector. Micro-ATX – This is a smaller form factor that is designed to be backward-compatible with ATX.