Computer System

PC HARDWARE SERVICINGThe Strengthened Technical-Vocational Education Program

How to Use this Module......................................................................................................... i................................................................................................................... 1

Introduction.......................................................................................................................... ii

Technical Terms.................................................................................................................... iii

Learning Outcome 1..............................................................................................................6

Information Sheet 1.1...........................................................................................................7

Self Check 1.1......................................................................................................................10

Information Sheet 1.2.........................................................................................................12

Self check..................................................................................................................16

Information sheet 2.2......................................................................................................... 17

Self Check 2.2......................................................................................................................19


Self-Check 2.3..................................................................................................................... 23


Self Check 2.4..................................................................................................................... 28




Self Check 2.5......................................................................................................................40

Operation Sheet 2.1............................................................................................................41

Learning Outcome 3............................................................................................................42



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Self Check 3.1......................................................................................................................49

Answer Keys........................................................................................................................50

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Welcome to the Module “Introducing Computer System”. This module contains training materials and activities for you to complete.

The unit of competency “Introduce Computer System” contains knowledge, skills and attitudes required for a Computer Hardware Servicing NC II course.

You are required to go through a series of learning activities in order to complete each of the learning outcomes of the module. In each learning outcome there are Information Sheets and Activity Sheets. Follow these activities on your own and answer the Self-Check at the end of each learning activity.

If you have questions, don’t hesitate to ask your teacher for assistance.

Recognition of Prior Learning (RPL)

You may already have some of the knowledge and skills covered in this module because you have:

o been working for some timeo Already have completed training in this area.

If you can demonstrate to your students that you are competent in a particular skill or skills, talk to him/her about having them formally recognized so you don’t have to do he same training again. If you have a qualification or Certificate of Competency from previous training shows it to your students. If the skills you acquired are still current and relevant to this module, they may become part of the evidence you can present for RPL. If you are not sure about the currency of your skills, discuss it with your teacher.

After completing this module ask your teacher to assess your competency. Result of your assessment will be recorded in your competency profile. All the learning activities are designed for you to complete at your own pace.

Inside this module you will find the activities for you to complete followed by relevant information sheets for each learning outcome. Each learning outcome may have more than one learning activity.

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Program/ Course: Computer Hardware Servicing NC IIUnit of Competency: Introduce Computer System Module: Introducing Computer System

INTRODUCTION:

This module contains information and suggested learning activities on Computer Hardware Servicing. It includes training materials and activities for you to complete.

Completion of this module will help you better understand the succeeding module on Computer Hardware Servicing.

This module consists of 3 learning outcomes. Each learning outcome contains learning activities supported by each instruction sheets. Before you perform the instructions read the information sheets and answer the self-check and activities provided to as certain to yourself and your teacher that you have acquired the knowledge necessary to perform the skill portion of the particular learning outcome.

Upon completion of this module, report to your teacher for assessment to check your achievement of knowledge and skills requirement of this module. If you pass the assessment, you will be given a certificate of completion.

SUMMARY OF LEARNING OUTCOMES:

Upon completion of the module you should be able to:

LO1. Essential Computer Components

LO2. Identification of computer parts and peripherals

LO3. Computer maintenance procedure

ASSESSMENT CRITERIA:

Refer to assessment criteria of learning outcomes #1-3 of this module.

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Learning Outcome #1: Identify Essential Computer Components


1. Essential computer components are identified.2. Characteristics of hardware, software and firmware are identified.3. Distinguish the relationship of hardware and software in a computer system.

RESOURCES:

Equipment and Accessories Tools MaterialsLAN CardUPS24 port-HubModemFax MachinePCUSB External CD writerUSB ScannerUSB PrintersUSB Flash Drive

Screwdriver(standard)Screwdriver(Philips)Long nose pliersMechanical pliersAllen wrenchMulti-testerCrimping toolsWire StripperLAN TesterAnti-static wrist wrapDevice drivers/installers

Software ApplicationsRJ 45UTP Cat 5 cableMotherboard’s Manual and InstallerSound Device Driver Installer

REFERENCES:

Antoinette R. Marcelo. Understanding PC Hardware. Copyright 2007 Jemma Inc.

http://www.empf.org/empfasis/aug04/prop.htm

http://www.lakeland.cc.il.us/~internal/policymanual/10fiscalaffairs/1026.POL.htm

www.gao.gov/new.items/d0871.pdf]

www.plant-materials.nrcs.usda.gov/pubs/nmpmcnl6045.pdf

www.cdpr.ca.gov

www.freepatentsonline.com

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http://www.cdpr.ca.gov/

http://www.plant-materials.nrcs.usda.gov/pubs/nmpmcnl6045.pdf

http://www.gao.gov/new.items/d0871.pdf


What are computers? Computers are electronic devices that are capable of processing data/information given

in the form of numbers, words, pictures, and even sounds. They can be programmed (given instructions) to carry out various kinds of information

processing jobs.

Application of Computers Various kinds of jobs that are done using computers: SCIENTIFIC COMPUTATIONS KEEPING TRACK OF INFORMATION -- BANKING, RAILWAYS OR AIRLINES RESERVATIONS PREPARATION OF DOCUMENTS AND MULTIMEDIA PRESENTATIONS SIMULATION OF REAL OR IMAGINARY WORLD SCENES – VIRTUAL REALITY, COMPUTER

GAMES STORING AND SHARING INFORMATION – WORLD WIDE WEB

Different Kinds of Computers Depending on the size and capacity, computers are classified into three types: MAINFRAME COMPUTERS MINICOMPUTERS MICROCOMPUTERS OR PERSONAL COMPUTERS.

Mainframe Computers Large and powerful computers that are used by many people (users) at the same time;

typically installed in large organizations. Located in a central place and accessed by users via computer terminals or other

computers placed at different locations and connected to the mainframe computer.

Supercomputers Extremely powerful mainframe computers used in scientific and engineering

applications.

Minicomputers• Minicomputers are medium sized computers -- Between Mainframe computers

and Microcomputers• Are also used by many users at the same time

• Used in small organizations.

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Components of a Computer

The components of a computer are classified into the three main categories – hardware, software and documentation Hardware: The mechanical and electronic parts that perform the various

tasks of the computer Software: The programs or instructions that tell the hardware what tasks

are to be done and how. Firmware/Documentation: Instructions in read only memory (ROM).

Hardware components

The hardware of a typical computer system, irrespective of its size, consists of the following components:

CENTRAL PROCESSING UNIT -- CPU MEMORY STORAGE DEVICES INPUT DEVICES OUTPUT DEVICES.

Computer Software/Program A software/program is a sequence of commands written in a computer

programming language that specifies a task the computer will perform. Some of the computer programming languages are: VISUAL BASIC,C, C++, JAVA

Classification of Computer SoftwareComputer software can be classified into following categories:

OPERATING SYSTEM USER PROGRAMS APPLICATION PROGRAMS

Operating System• Operating system (OS) is the basic software responsible for interacting with the

hardware.• It is the foundation on which user programs and application programs are built.

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• It helps the user to enter programs or data, store them in files and execute programs.

• Two popular operating systems in use today are Unix – for mainframes and minicomputers. Windows and Linux – used for personal computers.

User Programs

• User Programs: Written by users or programmers for themselves or for their organization.

Application Programs• Computers are increasingly being used in almost every activity - business,

industry, commerce, health, education, entertainment, sports, etc. • Application programs is the catch-all name for all programs that are used for

carrying out specific tasks - office document creation, pay roll processing, …

Word processing Desktop Publishing Spreadsheets

Firmware

Program that is embedded in a silicon chip rather than stored on a floppy disk

Example: BIOS chip or CMOS

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Multiple choice:

1. What do you call a program imbedded on a silicon chip?a) Peopleware b) Software c) Firmware d) Hardware

2. What do you call software that interacts with the computer hardware?a) Applications b) Operating System c) Firmware d) Spreadsheets

3. The mechanical and electrical part of the computer system.a) Software b) Hardware c) Unix d) Firmware

4. An operating system used in mainframes and mini-computers.a) Windows XP b) Unix c) Panda d) BIOS

5. An example of an operating system commonly installed in personal computers.

a) Unix b) Windows c) BIOS d)MS-Word

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Learning Outcome #2: Identify of computer parts and peripherals


1. Appropriate personal protective equipment conforms to the standard procedures.

2. Appropriate tools are used.3. Identification of the different computer parts is observed.4. Characteristics and functions of each computer component are identified.

REFERENCES:

http://en.wikipedia.org/wiki/Customer_service

http://en.wikipedia.org/wiki/Quality_standard

http://www.technet.unsw.edu.au/tohss/swp.htm

http://xnet.rrc.mb.ca/healthsafety/safeworkprocedures




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Your PC’s system case is probably high on the list of components you think about the least. However, in spite of the fact that the system case has only one or two components that are active, namely the power supply and the front panel, the PC’s case plays a major role in the PC’s operation.

In spite of the fact that the PC’s case just seems to sit there, it does perform a number of very valuable functions.

Provides the aesthetics of the system Provides the PC with its structure Provides protection and cooling for the electronics and other devices

mounted inside

Computer case comes in al sizes, shapes, colors and faces. These variations in size and shape are driven by the case’s form factor. The form factor of the case is its shape, the way its components fit together and most of all its size. Typically, the form factor of a PC includes its case, power supply and motherboard, because these components must fit together to supply protection, power and safety.

Chassis the skeletal framework that provides the structure, rigidity and strength of the case.

Cover plays an important role in the cooling, protection and structure of the PC.

Power Supply a very important component, not only to the case assembly, but to the PC and its other components.

Front panel in addition to providing the PC with its looks and color, the front panel also provides information on the PC’s status, allows the user to physically secure the PC and on some case types, it is the starting point for removing the case cover.

Power switch Reset switch Status LED

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Power LED typically green in color and illuminated when the PC’s power is on.

Hard drive LED when the drive is seeking, reading or writing data, this red, orange or amber LED is lit and flashes.

Turbo LED if present, this yellow LED indicates that the PC is in turbo mode.

Switches most new systems now have their two main switches, the power switch and the reset switch, on the front panel.

Power button - in older PCs, the power switch was a part of the power supply and located on the right rear corner of the PC.

Reset button performs a hardware reset when pressed. This provides the user with a means of restarting the PC should it halt and not respond to normal shutdown or restart command.

Turbo button Key lock

Keyboard lockout Front-panel door lock

Drive bays disk drives with removable media have been mounted in the system case so that they can be accessed from the front panel. Typically, the drive bays are used for 3.5-inch disk drives, CD ROMs, DVDs and removable hard drives.

External drive bays these drive bays are actually internal to the case and chassis, but they can be accessed externally.

Internal drive bays these drive bays are completely inside the system case and are not accessible from outside the chassis

System Case Styles1. Desktop case – the flat, boxy one is the desktop case PC. It doubles as the

base for PC’s monitor.2. Tower cases – the tall, thin case are the tower style. Below are the

popular variations of the tower case

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Cover

Switches

Drive Bays

Front Panel

Power Supply

Chassis


Full tower are the largest standard PC cases available. They offer the most of any case style in the way of expandability, typically having three to five external drive bays and a few internal drive bays as well.

Mid-tower is a slightly shorter version of the full tower. Midi-tower exist somewhere between the mid-tower and the

mini-tower. By definition, a midi-tower is smaller than a mid-tower and larger than a mini-tower.

Mini-tower this is the most popular case today. It provides slightly more expansion capacity than desktop cases.

Computer Case

Tower Case

System Case Form FactorsThe three most popular types of case form factors are:1. Baby AT- though virtually obsolete by today’s standards, the Baby AT form factor is still

considered popular because of its very large installed base stemming from its popularity in past years. The Baby AT is a smaller version of the AT form factor that is narrower in width, but otherwise shares the AT form factor’s dimensions.

2. ATX – Intel developed this form factor in the mid-1990s and it has become the form factor for motherboards and system cases. All Pentium-based systems require motherboards and chipsets that use the ATX form factor specification.

3. NLX – also called Slim-line form factor, is quickly becoming the new standard for mass-produced desktop system because it offers manufacturers more flexibility and room for future advancement.

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Three different sizes of cases are available in the tower model:

Baby or Mini - Tower

o 14 or fewer inches tall

o 2 or fewer 5.25-inch bays

o 1 3.5-inch bay

Mid - Tower

o 16 to 18 inches tall

o 3 to 4 5.25-inch bays

o 1 or more 3.5-inch bays

Full Tower

o 20 inches or taller



Power supplies from 150 to 500 watts

The power supply

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Multiple-choice

1. It is the skeletal frame work of your computer system.a) Cover b) Chassis c) Screws d) Power supply

2. It provides protection for the internal parts of the computer.a) Chassis b) Reset c) Case d) Cover

3. The part of the computer that provides power to the entire system?a) CPU b) Drive Bay c) Power Supply d) Reset

4. A button that allows the user to restart the computer.a) Reset b) Turbo c) LED d) Power switch

5. The part of the chassis where you place the internal drives.a) Drive Bay b) Cover c) Chassis d) CPU

Identification

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What is a power supply and what does it do? The power supply unit (PSU) in a PC regulates and delivers the power to the components in the case.

Power Supplies contain dangerous voltages and should only be opened by experienced and qualified engineers, there are no user serviceable parts inside.

Always disconnect the PSU from the mains supply before removing the cover of the PC.

Standard power supplies turn the incoming 110V or 220V AC (Alternating Current) into various DC (Direct Current) voltages suitable for powering the computer's components.

Power supplies are quoted as having a certain power output specified in Watts, a standard power supply would typically be able to deliver around 350 Watts.

The more components (hard drives, CD/DVD drives, tape drives, ventilation fans, etc) you have in your PC the greater the power required from the power supply.

By using a PSU that delivers more power than required means it won't be running at full capacity, which can prolong life by reducing heat damage to the PSU internal components during long periods of use.

Always replace a power supply with an equivalent or superior power output (Wattage).

There are 3 types of power supply in common use:

AT Power Supply - still in use in older PCs.

ATX Power Supply - commonly in use today.

ATX-2 Power Supply - recently new standard.

The voltages produced by AT/ATX/ATX-2 power supplies are:

+3.3 Volts DC (ATX/ATX-2)

+5 Volts DC (AT/ATX/ATX-2)

-5 Volts DC (AT/ATX/ATX-2)

+5 Volts DC Standby (ATX/ATX-2)

+12 Volts DC (AT/ATX/ATX-2)

-12 Volts DC (AT/ATX/ATX-2)

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A power supply can be easily changed and are generally not expensive, so if one fails (which is far from uncommon) then replacement is usually the most economic solution.

The power supply connectors 4 Pin Berg ConnectorUsed to connect the PSU to small form factor devices, such as 3.5" floppy drives. available in: AT, ATX & ATX-2

4 Pin Molex ConnectorThis is used to power various components, including hard drives and optical drives. available in: AT, ATX & ATX-2

20 Pin Molex ATX Power ConnectorThis is used to power the motherboard in ATX systems. available in: ATX( ATX-2 have four extra pins)

4 Pin Molex P4 12V Power ConnectorUsed specifically for Pentium 4 Processor Motherboards. available in: ATX (integrated into the power connector in ATX-2)

6 Pin AUX ConnectorProvides +5V DC, and two connections of +3.3V. available in: ATX/ATX-2

ATX Power Supply Pin outs Below are pin out diagrams of the common connectors in ATX power supplies.

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Direction: Identify the name of each connector found in the power supply.

The power supply connectors

1.

2.

3.

4.

5.

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The motherboard is easily the most important part of the computer. Although there are a number of components that a PC cannot function without, it’s the motherboard that ties them all together and turns them into a personal computer.

The motherboard, or mainboard, of a PC is a large printed circuit board that is home to many of the most essential parts of the computer, including the microprocessor, chipset, cache, memory sockets, expansion bus, parallel and serial ports, mouse and keyboard connectors and IDE, EIDE or SCSI controllers. Thee motherboard binds the PC’s operational components together.

Motherboard Designs

Not all motherboards are created equal. Two different design approaches are used for PC mainboards: the motherboard style and the backplane style.

1. Motherboard Style – also known as mainboard, system board or planar. It aggregates all the PC’s primary system components on a single printed circuit board. In the motherboard’s single board design, al of the PC’s electronic circuitry that provides the conduit through which all operations flow is located on the motherboard.

2. Backplanes – are common in large PC network servers and on other computers on which the processor is upgraded frequently. In its basic form, a backplane mainboard contains very little in the way of intelligence and storage capabilities. It is merely a receptacle board into which processor cards, memory cards and other component boards are inserted to add capability to a PC.

Motherboard Form Factors

Form factors define a motherboard’s size, shape and how it is mounted to the case. However, form factors now include the size, shape and function of the system case; the type, placement and size of the power supply; the system’s power requirements; the location and type of the external connectors, and the case’s airflow and cooling system.

Micro-AT Form FactorThis is nearly half the size of the Baby AT main board.

LPX and Mini-LPX These are not actually form factor because they lack a specific motherboard

standard; they are more of a general motherboard design.

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ATX Form FactorIt was released by Intel in 1995 and was an improvement over the LPX form factor.

Mini ATXThis is slightly smaller than ATX but all the specifications of the ATX are included.

NLX Form FactorA new standardized form factor. The three primary focuses of the NLX are the

processor and system cooling, the number of connections for multimedia hardware and reducing the clutter of interior cables.

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The Components of the Motherboard

1. CPU slot and socket 2. Chipset 3. Memory Sockets 4. BIOS ROM5. CMOS battery6. Power Connector7. I/O Connectors8. Expansion Slots

Upgrading a Motherboard

Here is a list of criteria you should consider when evaluating your PC and deciding how to upgrade it.

1. CPU2. Socket and Slots3. Bus Speed4. Cache Memory5. Memory Modules6. Expansion Bus7. BIOS8. Chipset9. Form Factor10. Built-in Controllers and Interfaces11. Documentation

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Multiple-choice:

1. What do you call the large printed circuit board inside your computer?a) CPU b) Mother board c) Video Card d) PSU

2. What type of motherboard design that is common in large PC network servers and on other computers on which the processor is upgraded frequently?

a) Motherboard b) CPU c) Backplanes d) ATX

3. What type of form factor that was released by Intel in 1995 and was an improvement over the LPX form factor?

a) AT b) BABY AT c) NLX d) ATX

4. It defines a motherboard’s size, shape and how it is mounted to the case?a) Motherboard b) Form factor c) LGX d) PSU

5. It is also known as mainboard, system board or planar?a) Motherboard b) Motherboard Style c) CPU d) LXG

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WHAT IS A CPU?

CPU stands for Central Processing Unit. There can be several processors in a computer, but one of them is the central one – the CPU.

The reason the CPU is called a processor is because it can work with data. And it has two important jobs:

It can do calculations. It can move data.

The CPU is very fast at doing both jobs. The faster the CPU can do calculations and move data, the faster we say the PC is. What follows is a short description of how to achieve faster data processing. Read it, and see if you understand all the concepts. There are three ways to improve a PC’s performance.

AMD Processor Intel Processor

The Evolution of the PC MicroprocessorsOther manufactures, such as AMD, VIA Cyrix and others make excellent processors,

but Intel is by far the leading manufacturer of PC microprocessors. So let us first look at the Intel CPU Family Tree

1. First Generation: 8088, 8086, 80188, 80186and 8087 – these were introduced in 1978 and had a clock speed of 4.77MHz. these were packaged ina40-pin dual line integrated circuit.

Intel 8088

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2. Second Generation: 80286 and 80287 – it has a clock speed of 6 to 8 MHZ and uses 16 bit data bus.

80286 CPU

3. Third Generation: 80386, 80386 DX, 80386SX, 80387, 80387SX – this was a full 32 bit processor and has clock speed of 16 MHz.

80386 DX vs. 80286

4. The Fourth Generation: 486DX, 486SX, 486DX2, 486SX2 and 486DX4 – this CPU incorporates a cache memory and an integrated math coprocessors. This was the first to use Intel’s new socket numbering system, the Socket 1.

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486DX and Socket 1

5. The Fifth Generation: Intel “P5” Pentium and Pentium MMX “P5” was originally known as 80586, but Intel found out that model numbers

could not be copyrighted. So, instead of numbers, they used a trademark name, Pentium.

MMX (Multimedia Extension or matrix math) improves internal speed and support graphic compression and decompression.

6. The Sixth Generation, Part1 : ‘P6” Pentium Pro, Pentium II, Celeron and Pentium II Xeon

Pentium Pro was developed as a network server processor.Pentium II is the Intel Pentium Pro with MMX technology. This is the first

Pentium to use the Slot1.

Celeron is used in desktop and portable computers and it is the low cost model of the Pentium II. It is initially released as Slot 1 CPU, but it is the first Pentium to use the Socket 370.

Pentium II Xeon is the successor to Pentium Pro but with enhance capability.

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Intel Pentium Pro and Socket 8

CPU Accessories

CPU Cooling System

CPU Fan

CPU Heat sink – It is use to cool down the processor.

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Identification:

1.__________________: it has a clock speed of 6 to 8 MHZ and uses 16 bit data bus.2.__________________; this CPU incorporates a cache memory and an integrated math coprocessors. This was the first to use Intel’s new socket numbering system, the Socket 1.3.__________________: these were introduced in 1978 and had a clock speed of 4.77MHz. 4.__________________: this was a full 32 bit processor and has clock speed of 16 MHz. 5.__________________ : was originally known as 80586, but Intel found out that model numbers could not be copyrighted.

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Computer Ports and Connectors (External)

The first input and output devices you encounter are the external devices, such as the keyboard, video monitor, printer and so forth. Some of these devices have connectors that are the same as, or very similar to, the connectors used for other devices. In most cases plugging a new device into the wrong connector can damage the device or the system, so you need to know all the different connectors and which devices use them.

Baby-AT system - connectors are found on the adapter cards in their slots, with only the keyboard connector coming directly off of the motherboard.

AXT system – the keyboard, mouse, serial and parallel ports almost always are mounted directly on the chassis and, at the same time, soldered directly to the motherboard without any cabling. These are called integrated or embedded ports or controller.

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NLX system - New Low Profile eXtension, the adapter cards do not plug directly into the motherboard slots. Instead, there is usually one vertically mounted riser card that “rises up” from the motherboard and holds the system I/O bus slots that the adapter cards then plug into.

Connector Types / Images

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Mouse Port

Keyboard Port

Parallel Port

USB Port Serial Port


This is the most common input device. The keyboard allows the user to communicate with the PC through keystrokes the represent character data and commands.

Keyboard Layout and Design1. 83-keys PC/XT keyboard – the keyboard included in the original IBM PC and the

XT

2. 84-keys AT keyboard – it is a step closer to the standard keyboard layout used today

3. Enhanced 101- keys keyboard - it is the one most familiar to computer users today. Later models are really just enhancements of the design. This is the industry standard today.

4. Windows 104- keys keyboard – this is identical to 101-keys keyboard layout except for the addition of three new keys; two Windows keys, located between the CTRL and ALT keys on both sides and an Application key on the right side, next to the Windows key.

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5. Natural and Ergonomic Keyboard – this keyboard help relieve the stress caused by the position of the user’s hands and wrist and prevent repetitive stress injuries such as carpal tunnel syndrome. The keyboard’s central bank of keys is split in half and each half rotated outward, to provide the user a more natural hand position.

6. Laptop/Portable PC Keyboard – this is smaller than normal keyboards. Adjustments are made in terms of key arrangements, layout and even functions to fit all the keys users requires.

7. Miscellaneous Keyboard Layouts - this are special keyboards to perform a variety of functions, such as; Internet Keyboard – includes button to connect to the Internet, open browser or check e-mails. Multimedia Keyboard – includes audio controls such as volume and CD controls.

Keyboard Elements1. Alphanumeric keys – the alphabet keys along with row numbers and special

characters. These keys match those on a typewriter. Alphabet keys Punctuation and special characters Actions keys

Character selection keys Command control keys

Enter key White space keys Number/special character keys

2. Cursor control key – located on the right side of the alphanumeric keys, this group of keys has two smaller group of keys: the cursor function keys and cursor arrow keys.

3. Function keys- located across the top of a keyboard.4. Numeric keypad – the number pad, which is located on the extreme right side of

nearly all modern keyboards, contains keys for ten numbers, as well as the four

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arithmetic functions. This can also be used as a cursor control pad by toggling the NUM LOCK key.

5. Toggle and Lock keys 6. Special purpose keys

ESC key Print Screen key Pause/break key

7. Window keys Windows key Application/Context key

Keyboard Switch Types1. Pure mechanical switches – a very simple switch in which two metal

contacts are brought into contact or metal plunger is pressed against contacts on a circuit board when the switch is pressed.

2. Foam element switches – it is made up of a plunger that is connected to a foam pad that has a piece of foil on its underside. A circuit board with a pair of copper contacts for each keyswitch sits underneath the keyswitches.

3. Rubber dome key switch – also known as carbon-contact keyswitch, this design is very much like the foam and foil contact switch. In each rubber dome switch is a small rounded dome of rubber that has a pad of carbon material on its underside.

4. Membrane switches – similar to rubber-dome switches, except that the keytops are all joined into a solid sheet that rest on top of the rubber domes.

Keyboard Connectors1. The 5 pin DIN connector - this is the oldest of the keyboard connectors, also

known as the AT form factor.Pin Number Signal

1 Keyboard Clock2 Keyboard Data3 Unused4 Ground5 + 5v Power

2. The 6 pin Mini DIN Connector – it is designed to used six pins arranged in a circular pattern around a plastic case, also known as PS/2 connector.

Pin Number Signal1 Keyboard Data2 Unused3 Ground4 + 5v Power5 Keyboard Clock6 Unused

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3. The USB Connector – the universal serial bus is a multifunction peripheral bus that is growing rapidly in popularity, and the keyboard is one of many devices that can use it.

4. IrDA (infrared) connector - it is a wireless keyboard.

Pointing Devices1. Traditional Mice/Mouse - a palm-sized plastic housing with a rubber ball

protruding from the bottom and a cord coming out the back. Ergonomic mice Optomechanical mice Optical mouse Intellimouse

2. Trackballs – it is an upside-down mouse with a larger than normal ball. Instead of rolling the ball by moving the whole mouse across a surface, you move the ball directly while the device itself remains stationary.

3. IBM /Track Point – also known as Glidepoint mouse. It is created by IBM for its ThinkPad line of notebook computer to solve the pointing device problems.

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4. Touch Pads – it is a rectangular pad located below the spacebar on a laptop keyboard. The pad senses the capacitance of your finger as you move it across the surface.

5. Joystick – a type of pointing device that is used primarily with game software on a PC.

6. Graphic Tablets – similar in conception with the touch pad, but it is larger and used with a stylus instead of your finger.

Pointing Device Interface Types Serial Port Connections Ps2 USB Connections Wireless

Mice first broke onto the public stage with the introduction of the Apple Macintosh in 1984, and since then they have helped to completely redefine the way we use computers.

Optical Mice

Developed by Agilent Technologies and introduced to the world in late 1999, the optical mouse actually uses a tiny camera to take thousands of pictures every second.

Able to work on almost any surface without a mouse pad, most optical mice use a small, red light-emitting diode (LED) that bounces light off that surface onto a complimentary metal-oxide semiconductor (CMOS) sensor. In addition to LEDs, a recent innovation are laser-based optical mice that detect more surface details compared to LED technology. This results in the ability to use a laser-based optical mouse on even more surfaces than an LED mouse.

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Optical mice have several benefits over track-ball mice:

No moving parts, means less wear and a lower chance of failure. There's no way for dirt to get inside the mouse and interfere with the tracking

sensors. Increased tracking resolution means a smoother response.

They don't require a special surface, such as a mouse pad.

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SENSOR


Hard Disk Basics

Hard disks were invented in the 1950s. They started as large disks up to 20 inches in diameter holding just a few megabytes. They were originally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product). They later became known as "hard disks" to distinguish them from "floppy disks." Hard disks have a hard platter that holds the magnetic medium, as opposed to the flexible plastic film found in tapes and floppies.

At the simplest level, a hard disk is not that different from a cassette tape. Both hard disks and cassette tapes use the same magnetic recording techniques described in How Tape Recorders Work. Hard disks and cassette tapes also share the major benefits of magnetic storage -- the magnetic medium can be easily erased and rewritten, and it will "remember" the magnetic flux patterns stored onto the medium for many years.

Here is a typical hard-disk drive:

Inside the Hard Disk

Platters

Arm

The platters - These typically spin at 3,600 or 7,200 rpm when the drive is operating. These platters are manufactured to amazing tolerances and are mirror-smooth.

The arm - This holds the read/write heads and is controlled by the mechanism in the upper-left corner. The arm is able to move the heads from the hub to the edge of the drive. The arm and its movement mechanism are extremely light and fast. The arm on a typical hard-disk drive can move from hub to edge and back up to 50 times per second.

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The Floppy Disk

The floppy disk drive (FDD) was the primary means of adding data to a computer until the CD-ROM drive became popular. In fact, FDDs have been a key component of most personal computers for more than 20 years.

Basically, a floppy disk drive reads and writes data to a small, circular piece of metal-coated plastic similar to audio cassette tape. In this article, you will learn more about what is inside a floppy disk drive and how it works. You will also find out some cool facts about FDDs.

History of the Floppy Disk Drive

The floppy disk drive (FDD) was invented at IBM by Alan Shugart in 1967. The first floppy drives used an 8-inch disk (later called a "diskette" as it got smaller), which evolved into the 5.25-inch disk that was used on the first IBM Personal Computer in August 1981. The 5.25-inch disk held 360 kilobytes compared to the 1.44 megabyte capacity of today's 3.5-inch diskette.

The 5.25-inch disks were dubbed "floppy" because the diskette packaging was a very flexible plastic envelope, unlike the rigid case used to hold today's 3.5-inch diskettes.

By the mid-1980s, the improved designs of the read/write heads, along with improvements in the magnetic recording media, led to the less-flexible, 3.5-inch, 1.44-megabyte (MB) capacity FDD in use today. For a few years, computers had both FDD sizes (3.5-inch and 5.25-inch). But by the mid-1990s, the 5.25-inch version had fallen out of popularity, partly because the diskette's recording surface could easily become contaminated by fingerprints through the open access area.

Floppy disk

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Optical drives

An optical drive is a storage device that reads and writes information to CDs and DVDs. A Molex power connector provides the optical drive with power from the power supply. A PATA cable connects the optical drive to the motherboard.

CD-ROM Drive

Inside your CD-ROM

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Identification:

1.____________________: The inventor of the floppy disk.2. ___________________: is a storage device that reads and writes information to CDs and DVDs.3.____________________: These typically spin at 3,600 or 7,200 rpm when the drive is operating.4. ___________________: This holds the read/write heads and is controlled by the mechanism in the upper-left corner.5.____________________: A code name used in hard disk for IBM products.

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Equipment, Tools, and Materials:

Personal Computer complete with peripherals

Given the following tools, materials and equipment, identify the different parts of a personal computer starting from the front up to the internal parts of the PC.

You will be assessed using the criteria in the score card below.

PERFORMANCE SCORE CARD

Performance CriteriaScoring

1 2 3 4 5

1. The components is identified successfully.

2. The peripherals are identified successfully.

3. Safety precautions are carefully observed.

4. Connecting the proper connections are performed.

5 - Excellently Performed4 - Very Satisfactorily Performed

3 - Satisfactorily Performed2 - Fairly Performed

1 - Poorly Performed

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Learning Outcome #3: Preventive maintenance procedure


ASSESSMENT CRITERIA

1. Conformity and/or appropriateness of personal protective equipment with the standard procedures is checked and observed.

2. Confirmation of computer normal function conforms to correct operation and safety.

3. Periodic maintenance of the equipment is performed following manufacturer’s requirements.

4. Safety precautions are observed at all times.

RESOURCES:Equipment/Facilities Tools & Instruments Supplies & Materials

Computer peripheralsDesktop computersOHS guidelinesPhil. Environmental protection standardsMonitorsMotherboardPower supplyNetwork device and cablingsHubsSwitchesLAN CardsPrinters and ScannersRoutersUSB Flash Drives

Protective eye wearWire stripper with cutterPliers(Assorted)Screw drivers (Assorted)Soldering iron/gunDe-soldering toolFlashlightTweezersMirrorsAntistatic wrist wrapLAN TesterCrimping toolSoftware installerWork benchMagnifying glass

Floppy diskCompact Disk

REFERENCES:




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http://xnet.rrc.mb.ca/healthsafety/safeworkprocedures




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General Safety Guidelines

Follow the basic safety guidelines to prevent cuts, burns, electrical shock, and damage to eyesight. As is best practice, make sure that a fire extinguisher and first-aid kit are available in case of fire or injury

Fire Safety GuidelinesFollow fire safety guidelines to protect lives, structures, and equipment. To avoid an electrical shock, and to prevent damage to the computer, turn off and unplug the computer before beginning a repair.

Fire can spread rapidly and be very costly. Proper use of a fire extinguisher can prevent a small fire from getting out of control. When working with computer components, always consider the possibility of an accidental fire and know how to react. If there is a fire, you should follow these safety procedures:

Never fight a fire that is out of control or not contained.

Always have a planned fire escape route before beginning any work.

Get out of the building quickly.

Contact emergency services for help.

Be sure to locate and read the instructions on the fire extinguishers in your workplace before you have to use them. Safety training may be available in your organization.

It is important to know how to use a fire extinguisher. Use the memory aid P-A-S-S to help you remember the basic rules of fire extinguisher operation:

P - Pull the pin.A - Aim at the base of the fire, not at the flames.S - Squeeze the lever.S - Sweep the nozzle from side to side.

Personal Safety Guidelines

These are general guidelines for all types of troubleshooting, installation, and maintenance tasks. Take them seriously; they may keep you out of a dangerous situation.

Never work alone (in the computer lab). Always have someone to keep an eye out for any potential problem.

Always use protective eyewear or safety goggles when appropriate. Monitors, in particular, can implode and send fragments of glass at tremendous speeds (be careful when moving or adjusting these devices.)

Do not go barefoot when moving tool boxes or computer equipment.

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Never assume that an electrical device is safe to handle. Perform your tests with the device disconnected (when appropriate) from the power source.

Some tests must be conducted with power applied. Be extremely cautious when performing these tests.

High current is generally more dangerous than high voltage.

Only 0.3 amps are required to seriously injure or kill a person. This is not to say that voltage is not also extremely dangerous, only to say that a high- current device may be marked with a relatively low voltage. Always test equipment for dangerous energy levels with a volt/amp meter before handling the device.

Do not wear jewelry of any kind.

Necklaces, rings, and bracelets can unintentionally short out nearby components when working in the tight space of most electronic cabinets. Make certain that earrings are removed. They may fall off and land on the electrical components you are testing.

Potential Hazards with Computer Equipment

Printers Power Supply Electrical Outlets Monitors Cables

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Planning and preparing systematic maintenance procedure save time, money and frustration. It is a good idea and opportunity to learn the proper care and maintenance of your computer.

PC maintenance is an important topic for anyone who owns a PC. Looking after your PC properly ensures you of trouble-free use. Regular PC maintenance also keeps the machine’s performance optimal.

TYPES OF MAINTENANCE PROCEDURE:

1. Hardware maintenance is the testing and cleaning of equipment.

2. Information system maintenance is the routine updating of master files, such as adding and deleting employees and customers and changing credit limits and product prices.

3. Software or program maintenance is the updating of application programs in order to meet changing information requirements, such as adding new functions and changing data formats. It also includes fixing bugs and adapting the software to new hardware devices.

4. Disk or file maintenance is the periodic reorganizing of disk files that have become fragmented due to continuous updating.

Work place procedures

Identify hazards and assess risk.

Execution of OHS policies are carried out along with the task.

Following certain procedure is very important to perform a given operation or evolution or in reaction to a given event. The table below shows different elements and their corresponding performance criteria to be able to identify occupational health and safety hazards, and assess risk, as well as follow instructions and procedure in the workplace with minimal supervision. The students will also be capable of participating and contributing to OHS management issues.

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SAMPLE MAINTENANCE PLAN:

MONTHLY COMPUTER MAINTENANCE PLAN

JUNE JULY AUG SEPT OCT NOV DEC

Anti virus software checkups

Disk space utilization

Defragmentation of hard drives

Troubleshoot hardware and software issues

Personal Protective Device

There are tools and equipments used to protect the user and the computer system.Types of personal protective devices

1. Anti-static devices

2. Power surge protectors

3. Personal equipments

ESD (Electro Static Discharge)-A small amount of static electricity that can destroy small parts of your computer.

Anti-static devicesDevices designed to protect the computer from static electricity.

Examples:1. Anti-static wrist strap

2. Anti-static mat

3. Anti-static bag

4. Anti-static spray

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Power surge protectors

Devices designed to protect the computer from sudden power surges from intermittent power sources.

Examples:1. AVR (Automatic Voltage Regulators)

2. UPS (Uninterrupted Power Supply)

Personal Equipment1. Small paint brush

2. Screw drivers

3. Pliers and tweezers

4. Compressed air

5. Handheld vacuum

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Enumeration:

1. Enumerate four personal equipment used in PC maintenance.2. Enumerate three examples of anti-static devices.3. Name the three personal protective device.

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Self Check 1.11. C2. B3 B4. B5. B

Self Check 2.11. B2. D3. C4. A5. A

Self Check 2.21. 4 pin berg2. 4 pin molex3. 20 pin molex4. 4 pin molex P4 12 volt5. 6 pin AUC connector

Self Check 2.31. B2. C3. D4. B5. B

Self Check 2.41. 2nd Generation2. 4th Generation3. 1st Generation4. 3rd Generation

5. 5th Generation

Self Check 2.51. Alan Shugart2. Optical drives3. Platter4. Arm5. Winchester/Fixed Disk

Self Check 3.1

1 Personal Equipment Small paint brush

Screw drivers

Pliers and tweezers

Compressed air

Handheld vacuum

2. Anti-static wrist strap

Anti-static mat

Anti-static bag

Anti-static spray

3 Personal Protective Devices. Anti-static devices

Power surge protectors

Personal equipments

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Computer System

Documents

learning activity

learning outcomes

suggested learning activities

series of learning activities

particular learning

computer system module

self check16 information

succeeding module