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INFORMATION TECHNOLOGY(IT)
1.Introducere
Information technology (IT) is the design, development, implementation, support, and management of computer hardware and software applications. An IT professional is knowledgeable about computer systems and operating systems. This chapter will review IT certifications and the components of a basic personal computer system.
After completing this chapter, you will meet these objectives:
IT Technician
Explain IT industry certifications
This course will focus on desktop and laptop computers. It will also discuss electronic devices, such as personal digital assistants and cell phones.
Training and experience will qualify a technician to service these computers and personal electronic devices. You will gain the specialized technical skills needed to install, maintain, and repair computers. Earning an industry standard certification will give you confidence and increase your opportunities in IT.
This course is focused on the following two industry standard certifications:
After completing this section, you will meet these objectives:
IT Certification
Identify education and certifications
Information Technology (IT) is a term that encompasses the relationship between hardware, software, networks, and technical assistance provided to users. IT Essentials: PC Hardware and Software covers the information that a technician needs to be successful in IT. This course covers the following topics:
The IT Essentials course focuses on two hardware and software skills-based industry certifications: CompTIA A+ and EUCIP. This course is only an introduction into the world of IT. A technician may continue to study and earn the following certifications:
IT certifications can be used as credits for university and college degrees in areas such as computer science and telecommunications.
1CompTIA A+ Certification
1.1.2Deascribe the A+ Certification
Computing Technology Industry Association (CompTIA) developed the A+ Certification program. A CompTIA A+ certification, as shown in Figure 1, signifies that a candidate is a qualified PC hardware and software technician. CompTIA certifications are known throughout the IT community as one of the best ways to enter the information technology field and build a solid career.
An A+ Certification candidate must pass two exams. The first exam is CompTIA A+ Essentials. The second advanced exam depends on the type of certification desired. Each advanced exam assesses specialized skills in one of the following areas:
Comptia A+ Exam Essentials
All certification candidates must pass the A+
Essentials Exam (220-601). The exam covers the basic skills needed to install,
build, upgrade, repair, configure, troubleshoot, optimize, diagnose, and
maintain basic personal computer hardware and operating systems.
CompTIA A+ Exam IT Technician
The CompTIA A+ (220-602) exam assesses the field-service technician. Field
technicians work in both mobile and corporate technical environments.
CompTIA A+ Exam Remote Support Technician
The CompTIA A+ (220-603) exam assesses remote support technicians who are
responsible for assisting a customer without physically touching the customers
computer. A remote technician will often work in a call center environment
where technicians resolve operating system and connectivity issues over the
telephone or Internet.
A remote support technician is also called a help-desk technician, a call-center technician, a technical specialist, or a technical representative.
CompTIA A+ Exam Depot Technician
The CompTIA A+ (220-604) examination assesses the depot technician. The depot
technician has limited interaction with the customer and works primarily in a
workshop or lab. A depot technician is also called a bench technician.
1EUCIP Modules
Describe the EUCIP certification
The EUCIP IT Administrator program offers a recognized certification of competence in IT. The certification covers the standards prescribed by the Council of European Professional Informatics Societies (CEPIS). The EUCIP IT Administrator Certification consists of five modules, with a corresponding exam for each module. This course will prepare you for Modules 13.
Module 1: Computer
Hardware
The Computer Hardware module requires that the candidate understand the basic
makeup of a personal computer and the functions of the components. The
candidate should be able to effectively diagnose and
repair hardware problems. The candidate should be able to advise customers of
appropriate hardware to buy.
Module 2: Operating
Systems
The Operating Systems module requires that the candidate be familiar with the
procedures for installing and updating most common operating systems and
applications. The candidate should know how to use system tools for
troubleshooting and repairing operating systems.
Module 3: Local Area
Network and Network Services
The Local Area Network and Network Services module requires that the candidate
be familiar with the procedure of installing, using, and managing local area
networks. The candidate should be able to add and remove users and shared
resources. The candidate should know how to use system tools for
troubleshooting and repairing networks.
Module 4: Expert
Network Use
This module is beyond the scope of the IT Essentials course, although some of
the topics are covered. The Expert Network Use module requires that the
candidate understand LAN communication.
Module 5: IT Security
This module is beyond the scope of the IT Essentials course, although some of
the topics are covered. The IT Security module requires that the candidate be
familiar with security methods and features that are available for a standalone
or networked computer.
1.Basic Personal Computer System
1.2 Describe a computer system
A computer system consists of hardware and software components. Hardware is the physical equipment such as the case, storage drives, keyboards, monitors, cables, speakers, and printers. The term software includes the operating system and programs. The operating system instructs the computer how to operate. These operations may include identifying, accessing, and processing information. Programs or applications perform different functions. Programs vary widely depending on the type of information that will be accessed or generated. For example, instructions for balancing a checkbook are very different from instructions for simulating a virtual reality world on the Internet.
The following sections in this chapter discuss the hardware components found in a computer system.
1 Computer Case with Power Supply
1.3Identify the names, purposes, and characteristics of cases and power supplies
The computer case provides protection and support for the internal components of the computer. All computers need a power supply to convert alternating-current (AC) power from the wall socket into direct-current (DC) power. The size and shape of the computer case is usually determined by the motherboard and other internal components.
You can select a large computer case to accommodate additional components that may be required in the future. Other users may select a smaller case that requires minimal space. In general, the computer case should be durable, easy to service, and have enough room for expansion.
The power supply must provide enough power for the components that are currently installed and allow for additional components that may be added at a later time. If you choose a power supply that powers only the current components, it may be necessary to replace the power supply when other components are upgraded.
After completing this section, you will meet these objectives:
1.Types of Computer Cases
Describe Cases
A computer case contains the framework to support the internal components of a computer while providing an enclosure for added protection. Computer cases are typically made of plastic, steel, and aluminum and are available in a variety of styles.
The size and layout of a case is called a form factor. There are many types of cases, but the basic form factors for computer cases include desktop and tower. Desktop cases may be slimline or full-sized, and tower cases may be mini or full-sized, as shown in Figure 1.
Computer cases are referred to in a number of ways:
In addition to providing protection and support, cases also provide an environment designed to keep the internal components cool. Case fans are used to move air through the computer case. As the air passes warm components, it absorbs heat and then exits the case. This process keeps the components of the computer from overheating.
There are many factors that must be considered when choosing a case:
See Figure 2 for a list of features.
In addition to providing protection from the environment, cases help to prevent damage from static electricity. Internal components of the computer are grounded by attachment to the case.
NOTE: You should select a case that matches the physical dimensions of the power supply and motherboard.
Power Supply
Describe power supplies
The power supply, shown in Figure 1, converts alternating-current (AC) power coming from a wall outlet into direct-current (DC) power, which is a lower voltage. DC power is required for all of the components inside the computer.
Connectors
Most connectors today are keyed connectors. Keyed
connectors are designed to be inserted in only one direction. Each part of the
connector has a colored wire with a different voltage running through it, as
seen in Figure 2. Different connectors are used to connect specific components
and various locations on the motherboard:
NOTE: If you have a difficult time inserting a connector, try a different way, or check to make sure that there are no bent pins or foreign objects in the way. Remember, if it seems difficult to plug in any cable or other part, there is something wrong. Cables, connectors, and components are designed to fit together snugly. Never force any connector or component. The connectors that are plugged in incorrectly will damage the plug and the connector. Take your time and make sure that you are handling the hardware correctly.
Electricity and Ohm's Law
These are the four basic units of electricity:
Voltage, current, power, and resistance are electronic terms that a computer technician must know:
There is a basic equation that expresses how three of the terms relate to each other. It states that voltage is equal to the current multiplied by the resistance. This is known as Ohm's Law.
V = IR
In an electrical system, power (P) is equal to the voltage multiplied by the current.
P = VI
In an electrical circuit, increasing the current or the voltage will result in higher power.
As an example of how this works, imagine a simple circuit that has a 9 V light bulb hooked up to a 9-V battery. The power output of the light bulb is 100-W. Using the equation above, we can calculate how much current in amps would be required to get 100-W out of this 9-V bulb.
To solve this equation, we know the following information:
What happens if a 12-V battery and a 12-V light bulb are used to get 100 W of power?
100 W / 12 V = 8.33 amps
This system produces the same power, but with less current.
Computers normally use power supplies ranging from 200-W to 500-W. However, some computers may need 500-W to 800-W power supplies. When building a computer, select a power supply with sufficient wattage to power all of the components. Obtain the wattage information for the components from the manufacturer's documentation. When deciding on a power supply, make sure to choose a power supply that has more than enough power for the current components.
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.
COPUTER COMPONENTS
1.4 Identify the names, purposes, and characteristics of internal components
This section discusses the names, purposes, and characteristics of the internal components of a computer.
After completing this section, you will meet these objectives:
Motherboards
1.4.1 Identify the names, purposes, and characteristics of motherboards
The motherboard is the main printed circuit board and contains the buses, or electrical pathways, found in a computer. These buses allow data to travel between the various components that comprise a computer. Figure 1 shows a variety of motherboards. A motherboard is also known as the system board, the backplane, or the main board.
The motherboard accommodates the central processing unit (CPU), RAM, expansion slots, heat sink/fan assembly, BIOS chip, chip set, and the embedded wires that interconnect the motherboard components. Sockets, internal and external connectors, and various ports are also placed on the motherboard.
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. Various form factors exist for motherboards, as shown in Figure 2.
An important set of components on the motherboard is the chip set. The chip set is composed of various integrated circuits attached to the motherboard that control how system hardware interacts with the CPU and motherboard. The CPU is installed into a slot or socket on the motherboard. The socket on the motherboard determines the type of CPU that can be installed.
The chip set of a motherboard allows the CPU to communicate and interact with the other components of the computer, and to exchange data with system memory, or RAM, hard disk drives, video cards, and other output devices. The chip set establishes how much memory can be added to a motherboard. The chip set also determines the type of connectors on the motherboard.
Most chip sets are divided into two distinct components, Northbridge and
CPU Types and Socket Specification
1.4.2Explain the names, purposes, and characteristics of CPUs
The central processing unit (CPU) is considered the brain of the computer. It is sometimes referred to as the processor. Most calculations take place in the CPU. In terms of computing power, the CPU is the most important element of a computer system. CPUs come in different form factors, each style requiring a particular slot or socket on the motherboard. Common CPU manufacturers include Intel and AMD.
The CPU socket or slot is the connector that interfaces between the motherboard and the processor itself. Most CPU sockets and processors in use today are built around the pin grid array (PGA) architecture, in which the pins on the underside of the processor are inserted into the socket, usually with zero insertion force (ZIF). ZIF refers to the amount of force needed to install a CPU into the motherboard socket or slot. Slot-based processors are cartridge-shaped and fit into a slot that looks similar to an expansion slot. Figure 1 lists common CPU socket specifications.
The CPU executes a program, which is a sequence of stored instructions. Each model of processor has an instruction set, which it executes. The CPU executes the program by processing each piece of data as directed by the program and the instruction set. While the CPU is executing one step of the program, the remaining instructions and the data are stored nearby in a special memory called cache. There are two major CPU architectures related to instruction sets:
Some CPUs incorporate hyperthreading to enhance the performance of the CPU. With hyperthreading, the CPU has multiple pieces of code being executed simultaneously on each pipeline. To an operating system, a single CPU with hyperthreading appears to be two CPUs.
The power of a CPU is measured by the speed and the amount of data that it can process. The speed of a CPU is rated in cycles per second. The speed of current CPUs is measured in millions of cycles per second, called megahertz (MHz), or billions of cycles per second, called gigahertz (GHz). The amount of data that a CPU can process at the one time depends on the size of the processor data bus. This is also called the CPU bus or the front side bus (FSB). The wider the processor data bus width, the more powerful the processor is. Current processors have a 32-bit or a 64-bit processor data bus.
Overclocking is a technique used to make a processor work at a faster speed than its original specification. Overclocking is not a reliable way to improve computer performance and can result in damaging the CPU.
MMX is a set of multimedia instructions built into Intel processors. MMX enabled microprocessors can handle many common multimedia operations that are normally handled by a separate sound or video card. However, only software especially written to call MMX instructions can take advantage of the MMX instruction set.
The latest processor technology has resulted in CPU manufacturers finding ways to incorporate more than one CPU core onto a single chip. Many CPUs are capable of processing multiple instructions concurrently:
Case fan
1.4.3 Identify the names, purposes, and characteristics of cooling systems
Electronic components generate heat. Heat is caused by the flow of current within the components. Computer components perform better when kept cool. If the heat is not removed, the computer may run slower. If too much heat builds up, computer components can be damaged.
Increasing the air flow in the computer case allows more heat to be removed. A case fan, shown in Figure 1, is installed in the computer case to make the cooling process more efficient.
In addition to case fans, a heat sink draws heat away from the core of the CPU. A fan on top of the heat sink, shown in Figure 2, moves the heat away from the CPU.
Other components are also susceptible to heat damage and are sometimes equipped with fans. Video adapter cards also produce a great deal of heat. Fans are dedicated to cool the graphics-processing unit (GPU), as seen in Figure 3.
Computers with extremely fast CPUs and GPUs may use a water-cooling system. A metal plate is placed over the processor and water is pumped over the top to collect the heat that the CPU creates. The water is pumped to a radiator to be cooled by the air, and then re-circulated.
ROM Types
1.4.4 Identify the names, purposes, and characteristics of ROM and RAM
ROM
Read-only memory (ROM) chips are located on the motherboard. ROM chips contain
instructions that can be directly accessed by the CPU. Basic instructions for
booting the computer and loading the operating system are stored in ROM. ROM
chips retain their contents even when the computer is powered down. The
contents cannot be erased or changed by normal means. The different types of
ROM are shown in Figure 1.
NOTE: ROM is sometimes called firmware. This is misleading because firmware is actually the software that is stored in a ROM chip.
RAM
Random access memory (RAM) is the temporary storage for data and programs that
are being accessed by the CPU. RAM is volatile memory, which means that the
contents are erased when the computer is powered off. The more RAM in a
computer, the more capacity the computer has to hold and process large programs
and files, as well as enhance system performance. The different types of RAM
are shown in Figure 2.
Memory Modules
Early computers had RAM installed on the motherboard
as individual chips. The individual memory chips, called dual inline package
(DIP) chips, were difficult to install and often became loose on the
motherboard. To solve this problem, designers soldered the memory chips on a
special circuit board called a memory module. The different types of memory
modules are shown in Figure 3.
NOTE: Memory modules can be single-sided or double-sided. Single-sided memory modules only contain RAM on one side of the module. Double-sided memory modules contain RAM on both sides of the module.
Cache
SRAM is used as cache memory to store the most frequently used data. SRAM
provides the processor with faster access to the data than retrieving it from
the slower DRAM, or main memory. The three types of cache memory are shown in
Figure 4.
Error Checking
Memory errors occur when the data is not stored correctly in the RAM chips. The
computer uses different methods to detect and correct data errors in memory.
Figure 5 shows three different methods of memory error checking.
1.4.5 Identify the names, purposes, and characteristics of adapter cards
Adapter cards increase the functionality of a computer by adding controllers for specific devices or by replacing malfunctioning ports. Figure 1 shows several types of adapter cards. Adapter cards are used to expand and customize the capability of the computer:
Computers have expansion slots on the motherboard to install adapter cards. The type of adapter card connector must match the expansion slot. A riser card was used in computer systems with the LPX form factor to allow adapter cards to be installed horizontally. The riser card was mainly used in slim-line desktop computers. The different types of expansion slots are shown in Figure 2.
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