c10j lesson 1 reading - the computer and its makeup

7/24/2019 C10J Lesson 1 Reading - The Computer and Its Makeup

http://slidepdf.com/reader/full/c10j-lesson-1-reading-the-computer-and-its-makeup 1/17

The Computer and Its Makeup

Inside the Computer

Just about any PC course out there opens with a discussion about the PC workstation. This has been thestaple computer device of organizations and people across the globe for decades now. The picture below

represents what we normally think of when we consider a PC workstation.

The photo above shows a typical setup that includes a monitor, a keyboard and mouse, and a case thathouses all of the internal hardware. In the photo above, the mouse and keyboard are wireless as theyhave no cords attached to them.



So let’s crack open the typical computer case and see what it looks like inside. An empty case thatdoesn’t have any components typically looks something like this.

And when you add the components, they look something like this.



Let’s talk about these components one-by-one and what is involved from a technician’s standpoint.

1. Power Supply

The fact is that your computer needs power to operate, so therefore it requires a power supply unit orPSU. The power supply provides the electrical power for all of the essential components such asCPU, hard drives, motherboard, memory, optical drives, and motherboard. In order to provide powerto the computer, it must convert an alternative current called AC, which is obtained from the wallsocket, into direct current or DC, which is used by the computer components. Most power supplieswill have either a 110 V/220 V switch that you can manually set to choose either voltage or willautomatically detect which one. The power supply needs to supply the amount of power that yourcomputer needs to run properly. There are many charts and calculators out there to determine thepower your PSU must generate by inventorying the components of your computer and determiningtheir cumulative power-consumption demands. It is better to have a PSU that is too big than toosmall. Total power requirements for a personal computer may range from 250 watts to more than1000 watts for a high-performance computer with multiple graphics cards. Personal computers rarelyrequire more than 300–500 watts.

The connection between your power supply and the AC outlet is done through a power cord. Forobvious reasons, this power cord must use a plug compatible with the standard used in your country

or else you must use an adapter. The North American standard is the NEMA 5-15. You see this samepower cord on other electronic devices you may own such as your television. The picture belowshows this classic power cord.

The power supply has a fan on the backside. Though the PSU fan doesn’t play as critical role as itused to, this fan helps to provide the airflow required to cool the components that reside within thecomputer and helps to ensure that the computer retains its overall system temperature. There is agreat amount of heat generated within the computer, and without the aid of cooling devices such as

the PSU fan, the computer would overheat quickly which would cause irreparable damage. There arespecially designed cases with vents that allow better airflow through the system in which the powersupply fan can either blow out the air from the back or draw in cooler air, depending on the design ofthe system.

It is very important to make sure that the air vent for the PSU fan is free of dust and other collectedmaterials that may dampen or hamper the airflow. You can lightly brush off this exterior area of thePSU or use a can of compressed air to blow it clean.



Some of the internal devices that the power supply provides power for are connected to themotherboard which we will discuss next. Because these devices are plugged or integrated into themotherboard, the power supply needs to plug into the motherboard or the devices themselves. Powersupplies thus provide a series of connectors to connect the PSU to them. One type of connectorfeeds power to the motherboard. Most current ATX motherboards today require two powerconnectors from your power supply: a primary connector that carries all voltages that contains 20 or24 pins, and a secondary 12-volt “CPU” connector that includes four or eight pins and supplies powerfor the processor. The picture below shows a typical bundle of connectors offered by a power supply.

As you can see in the picture above, the majority of the connectors are 4-pin connectors. These arecalled Molex connectors and they connect to various hard drives and optical drives. If your computerhas a SATA drive then it will require a SATA adapter.

The article at http://en.kioskea.net/faq/3312-identify-the-connectors-of-the-power-supply does a great job of describing these connectors in detail.

The article at http://www.pcworld.com/article/2025425/how-to-pick-the-best-pc-power-supply.html describes how to pick the ideal power supply for your computer.



2. Motherboard

The motherboard's main job is to hold the computer's microprocessor chip and let everything elseconnect to it. Everything that runs the computer or enhances its performance is either part of themotherboard or plugs into it via a slot or port.

The shape and layout of a motherboard is called the form factor . The form factor affects whereindividual components go and the shape of the computer's case. There are several specific formfactors that most PC motherboards use so that they can all fit in standard cases.There are a number of critical components of the motherboard.

The socket for the microprocessor . The socket type determines what type of CPU the computerwill utilize.

The chipset is part of the motherboard's logic system and connects the CPU to other parts ofthe computer.

The Basic Input/Output System (BIOS) chip controls the most basic functions of thecomputer and performs a self-test every time you turn it on.

The real time clock chip maintains basic settings and the system time. This componentrequires a battery that needs to be switched out every once in a while.

A typical motherboard is shown below. Notice the various slots available on the motherboard.

Please read the article at http://www.ehow.com/topic_2904_motherboards.html which coversmotherboards in detail and some of the common tasks a technician will undertake regarding them.



3. Central Processing Unit (CPU)

A CPU processes data, plain and simple. It is literally the brain of the computer. It performs millions ofindividual calculations every second at phenomenal speeds. A CPU runs programs by fetchinginstructions from the computer’s memory, evaluating them, and executing them in sequence.

When you press a key on your keyboard, the CPU receives the input and will interpret the key stroke,sending a command to the monitor through your video card to display it. If you click the mouse on anicon to open a piece of software, the CPU interprets that command and opens the application. TheCPU can receive instructions from the software at extremely fast speeds and then perform the tasksthat are required to run the software. The CPU will instruct the rest of the hardware componentsinside your computer to do exactly what the software was written to do.

A good computer doesn’t have just a single processor. It most likely has a dual core processor whichactually contains two cores on the same processor, giving the computer two central processing unitsessentially and twice the processing power. It is not uncommon for a server today, which is a robustcomputer that shares resources for multiple users, to have a quad core processor. Having a dual coreCPU will allow you to run multiple pieces of software simultaneously without losing the performanceand speed that you would when running the same pieces of software on a single core CPU.

The two primary CPU families today are Intel and AMD. Intel(http://www.intel.com/content/www/us/en/homepage.html) is the industry leader and is considered ahigher end processor, while AMD (http://www.amd.com/us/Pages/AMDHomePage.aspxis) for themore budget-conscious computer owner. You can see examples of each below.



When you open up a traditional workstation, you might not see the CPU because it is buried beneatha CPU fan and/or heat sink and resides in its dedicated CPU slot on the motherboard. Both of thesedevices help to cool the CPU. A processor generates a tremendous amount of heat. You shouldnever directly touch a CPU until it has had time to cool down. All modern-day CPUs today have aheat sink. A heat sink without a fan is called a passive heat sink; a heat sink with a fan is called anactive heat sink. Heat sinks are generally made of an aluminum alloy and often have fans. Thepicture below shows an active heat sink with the fan residing on top of the heat sink. Go tohttp://www.techradar.com/us/news/computing-components/processors/how-do-cpu-coolers-work-721366 to learn even more about the fascinating process of the cooling process for today’s CPU.

The article at http://www.howstuffworks.com/microprocessor.htm adds a lot more insight intoeverything the CPU does on the computer.

4. Hard Drives

The hard drive is where the operating system that runs the device and its applications is located. Thisis where the user stores data and personal files. A traditional hard drive, also called a hard drive diskor HDD, is actually a collection of small DVD-like disks called platters that spin very fast around aspindle as an arm reads and writes to the disks. In fact, these spindles spin at a rate of 5400 RPM orrotations per minute. This creates a lot of heat and contributes to the noise level of the computer.

There are also solid-state drives or SSDs, which have no platters. Solid-state drives have a numberof advantages over HDD.

Faster I/O rate or in/out rate, in other words how fast the drive can read or write data

They use a lot less energy and run quieter since nothing is spinning

SSDs have no moving parts so there are fewer things to go wrong

SSDs are not affected by fragmentation (discussed in Lesson 8)

Hard drives come with two interfaces. One is an older technology called IDE/EIDE, which stands forIntegrated Drive Electronics and Enhanced Integrated Drive Electronics. The other is SATA, whichstands for Serial ATA or Advanced Technology Attachment. Most computers made in the last five toten years support IDE. Though not as fast as SATA drives, IDE is cheaper, which is why it is found ona lot of home computers. IDE ribbon connectors do take a lot of room within the case, however, whichdiminishes the air circulation inside. IDE ribbon cables are gray and have two rows of twenty pinswhich connect to both the motherboard and to the drive itself.



Below is a picture of an IDE Drive.

And its ATA ribbon.

EIDE is an improved version of the IDE drive interface that provides faster data transfer rates than theoriginal standard. While the original IDE drive controllers supported transfer rates of 8.3 Mbps, EIDEcan transfer data up to 16.6 Mbps, which is twice as fast. The term EIDE also refers to an ATAstandard known as ATA-2 or Fast ATA. Therefore, the terms EIDE, ATA-2, and Fast ATA may beused synonymously.

SATAs have only a thin wire as a connector so it takes up far less room, which is critical for a laptop

or notebook computer. SATA also has a much faster transfer rate of between 33 and 133 MBs(Megabits per second).



A SATA ribbon is shown below.

SCSI drives are theoretically much faster than either ATA or SATA drives and tend to be much morereliable and much quicker to boot and load programs. This all sounds great, but there are some hugedrawbacks. For one, SCSI drives require jumper settings, and very complex knowledge of SCSIsystems is necessary to get more than one or two drives going. They're also extremely expensive,often more than two or three times the price of a SATA drive. They charge a heavy premium for theirincreased performance and thus are mostly utilized for servers and other business-criticalapplications. Very few desktop computers are built with SCSI disks in mind.

While workstations use standard size 3.5” drives (3.5” is the diameter of the storage platters), thedrives for laptops come in either 2.5” or 1.8,” 2.5 being the most popular. Laptops only have a smallarea of space beneath their case so space is greatly limited. Below is the picture of a typical laptopEIDE drive.

Go to http://www.webopedia.com/DidYouKnow/Computer_Science/2007/sas_sata.asp for furtherreading on the various hard drive alternatives available today.



5. Memory

A hard drive stores non-volatile memory. Non-volatile memory is memory that can retain informationeven after the power is turned off. It is permanent memory if we can indeed use the word permanent.Volatile memory on the other hand is memory that loses its data as soon as the power is turned off.This is characteristic of what is referred to as Random Access Memory or RAM. RAM is temporarystorage. It is the memory that stores the data that is being processed in real time. For instance, youopen up Microsoft Word to create a document. The Word Application resides on a SATA drive whichis non-volatile memory. It is always there to be accessed. You then begin to create a new document.The document you are working on resides in RAM. When the document is completed, you save it toyour hard drive. If your computer lost power before you saved it, the document would be gonebecause it was never saved to non-volatile memory.

Computers today use a type of RAM called DIMM which stands for Dual Line Memory Module.Today’s more prevalent type of DIMM is DDR3 SDRAM, which stands for Double Data RateSynchronous Dynamic Random Access Memory. The 3 stands for 3

rd generation, and each

generation is twice as fast as the previous generation. The previous version is single data rate orSDRAM. DDR SDRAM was built on the technology of the prior version, but operates at almost twicethe bandwidth or processing speed.

DDR SDRAM is computer memory and serves as temporary storage for data. Memory such as DDR3is used by the computer for the temporary storage of data. RAM is far faster than non-volatile memoryso it is an ideal place for the computer to store data that the computer is working on. DDR Memorytransfers the data in 64-bit pieces. In order to accommodate this type of RAM, the operating systemthat manages your computer must support 64-bit.

A DDR SDRAM comes as a module that clips into a slot on the motherboard. There are a pair of clipsthat hold the RAM module in place. You must open these clips to insert and remove the memory.DIMM modules are not compatible. A motherboard that supports DDR2 will not accept DDR3 andvice versa. To ensure that a user doesn’t insert a DIMM into a motherboard that is incompatible, theDIMM modules have a notch on them that is located in a different place for each module, makingthem easily identifiable. They also have different pin counts. SDRAM has 168 pins, DDR SDRAM has184, and DDR2 and DDR3 have 240. Pictures of these DIMMs can be seen below.



You want to ensure that your computer has plenty of RAM. It’s hard to have too much memory. Whenyou purchase a computer, the memory is usually listed in the following format:

8GB (2GBx4) DDR3-SDRAM-1333

This means that the computer has a total of 8GB of memory that is made up of 4 DIMM modules andeach DIMM is 2GB. The memory used is DDR3 SDRAM which has a speed of 1333 MHz. Memory isoften placed in pairs. You usually have to insert DIMMs with the same amount of allocated memory ineach slot.

If RAM is temporary storage that your computer stores data currently being manipulated by thecomputer, then what happens if your computer is working with more data than the computer hasmemory? In this case, the computer has a spill-over area called the paging file. The paging file is adesignated area assigned to the hard drive that spills over from the RAM and is managed by thecomputer operating system. If your computer doesn’t have enough memory, it juggles data back andforth between the paging file and RAM as needed. This slows the computer down a lot becauseaccessing data from a hard drive is much slower than RAM. This is also referred to as drive thrashingas the hard drive is constantly spinning for the paging file, which then affects the performance of thedrive as well. Every time your hard drive is running, an LED light near it will flicker indicating activity.

A good sign that your computer doesn’t have enough memory is if this light is constantly flickering.

If you want to make your computer faster, the best thing you can do is add more memory, especiallywhen you consider how inexpensive RAM is today. Sometimes this may involve purchasing additionalDIMMs to insert into empty DIMM slots in your computer. For instance, you may have two 4GBmemory modules and two more empty slots. You would then insert two more 4GB memory modules,giving you a total of 16 of memory. If all of your memory slots are filled, you will then have to replaceyour DIMMs with larger ones, for instance replacing all of your 2GB DIMMs with 4GB DIMMs whichwould double your memory. Although purchasing a faster processor will speed up your computer aswell, doubling your memory will have a greater impact on performance than a processor upgrade.

Go to http://www.howtogeek.com/howto/windows-vista/what-kind-of-memory-does-my-computer-have-installed/ to read an article about how to find what type of memory is in your computer.

If you are interested in learning about memory requirements for the iPad go tohttp://ipad.about.com/od/iPad-Tutorials/a/How-Much-iPad-Memory-Do-You-Need.htm.



6. Optical Drives

An optical drive is a secondary storage device that offers removable storage. It is called removablestorage because you can take the data with you and swap it out. The three optical drives availabletoday are CD, DVD, and BD or Blu-Ray. Each of these three optical disk technologies has differentstorage abilities.

CD: about 700MB of data. They can play only CDs. DVD: about 4.7GB. DVD drives can also handle CDs. DVD DL, which stands for Dual Layer,

holds about 8.5GB.

BD: about 25GB. The drives are CD- and DVD-compatible. Blu-ray is so named because ituses a finer, blue-violet laser for reading data. The site http://www.blu-ray.com/faq/ cananswer all of your questions about Blu-ray.

Optical drives have a few more acronyms to understand.

ROM: "Read Only Memory" and indicates a disc that cannot be written to, only read.

R: This is a disc that can be written to once. This is applicable to all formats, but there's abifurcation here that needs to be discussed later on.

RW: This disc can be written to, erased, and written to again. This is again applicable to allformats.

RE: Only applies to Blu-Ray and is the equivalent of RW.

Optical drives connect to the motherboard either by an IDE or SATA connector.

7. USB Ports

All computers today come with USB ports. They have become the most commonly used way toconnect peripheral devices to a computer. These ports allow the user to insert USB standaloneelectronic devices into them. All computers today come with USB ports, which stands for UniversalSerial Bus ports. Like any hardware, USB devices have to be installed by the operating system, butthis process takes place automatically unless the operating system cannot determine what the deviceis or cannot locate a driver for it. Your mouse, printer, digital camera, scanner, and other devicesprobably all connect to your computer via a USB port. Many memory storage devices such asportable hard drives and flash drives are also commonly connected through USB ports. USB cableswill usually have two types of connectors, one on each end. There is a USB type A that is the end thatalways plugs into your computer. The other end has a different type of connector depending on whattype of device is being connected. Printers and some cameras take the Type B while phones andother types of handheld devices take Mini or Micro connectors. A chart is shown below.



Once installed onto the computer, the computer and the USB device can communicate with eachother. This connection may transfer data between the two devices, such as transferring music from acamera to a computer. It can also be used to power the device, such as charging a smartphone. Itcan also be used to allow an application on the computer to control the device, such as installingfirmware updates on a USB device.

Go to http://www.techradar.com/us/news/computing/usb-3-everything-you-need-to-know-638185 for agreat article on USB 3, the latest USB technology.

8. Types of External Devices

External devices are grouped into two categories, input devices and output devices. An input device is a device that sends data and commands to the computer. Input devices allow the user to integratewith the computer. Some common types of input devices include the following.

Keyboard

Mouse

Digital scanner (http://www.thefreedictionary.com/digital+scanner )

Digital camera

Stylus or pen (http://www.ask.com/question/how-does-a-stylus-pen-work)

Webcam

Output devices receive or display output from the computer. Some common types of output devicesinclude the following.

Printers

Monitors

Flat panels

Projector

Plotter (https://en.wikipedia.org/wiki/Plotter )

Speakers



Installing a Device

When you install a device for your computer, you are actually installing it with the operating system of thecomputer (Lesson 2 is all about operating systems). The operating system needs to be able tocommunicate with these devices. No matter how these devices are installed onto your computer, whetherinternally or USB, they need a driver to communicate with the operating system.

There are thousands and thousands of devices out there on the market that integrate with computers. Anoperating manufacturer can’t possibly keep track of all of the devices out there on the market, so OSmanufacturers such as Microsoft depend on the device manufacturers to create drivers that will install intotheir operating system and integrate the device with it. When you install a device, in a way you are literallyinstalling the driver of that device.

Take a printer for instance. Let’s say you are installing a new HP inkjet printer onto a Windows 8computer. If it is a popular printer, Windows 8 may have the driver already. If not, Windows 8 will either doa web search for the driver or prompt the user to provide the driver by specifying a location. The drivermay be provided on an installation disk provided by HP with the printer, or it may be downloaded by theuser into a folder on the computer.

A driver designed for Windows XP may not work for Windows 8, so sometimes drivers are operating

system specific so a driver designed for Windows 8 won’t necessarily work for Windows XP. A driver for a32-bit operating system will work for a 64-bit operating system and vice versa. You should look for driverupdates from time-to-time for all of your devices. Companies release updated drivers from time-to-time tofix bugs and errors found in previous versions. Most device manufacturers provide a way to downloaddrivers for their supported devices. If you need to locate drivers for an old device, there are third-partydriver websites that sell drivers for outdated devices.

Installing USB devices is very simple. Simply connect the USB device into one of the USB ports on thecomputer and the operating system will automatically detect the device. Whether it is the first time youconnect a new mouse, keyboard, printer, or camera, the operating system will install the designateddriver. Within a matter of minutes, the device is ready to run. USB devices are referred to as plug andplay devices. Plug them into the USB port and they are ready to run.

Occasionally you may need to install an internal device such as extra memory DIMMs or an internalNetwork Interface card. This is a more complicated process than installing a USB device. To install aninternal device that needs to be connected to the motherboard requires that you turn the computer off.Inserting a device into a connector on the motherboard will short the motherboard and you will have toreplace it.

Once you remove the cover of your computer case, you are ready to install the internal device into itsdesignated slot on the motherboard. During this process you must be conscious of electrostaticdischarge, otherwise known as ESD. ESD can damage or destroy the computer or selectedcomponents. Much like the shock you receives when rubbing your feet on the carpet and touchingsomething metal, ESD can occur when working in your computer and will cause components you touch tono longer work properly. ESD can occur without the user’s feeling a shock and will only occur whileworking on the inside of the computer.



Fortunately, it is very easy to avoid ESD while working on your computer. Most important, make sure youand the computer are at Zero Potential by continuously touching an unpainted metal surface of thechassis (http://www.computerhope.com/jargon/c/chassis.htm) or the computer power supply case. Somebasic steps to take are the following.

Remain standing at all times when working on the computer. Sitting on a chair can generate moreelectrostatic.

Always keep a part of your body such as a hand or arm in touch with a metal part of the computer. Unplug all cords: Make sure everything is removed from the back of the computer (power cord,

mouse, keyboard, etc.).

Wear the proper clothes: Make sure not to wear any clothing that conducts a lot of electricalcharge, such as a wool sweater.

Go to http://www.wikihow.com/Ground-Yourself-to-Avoid-Destroying-a-Computer-with-Electrostatic-Discharge for an article on how to avoid damaging your computer with ESD.

The Boot Process

Turning on a computer isn’t as simple as just hitting the power switch. There is a lot that goes on duringthe boot process. The boot process is the series of steps that a computer takes to start the computersystem and open up the operating system.

1. The power button activates the power supply in the PC, sending power to the motherboard andother components.

2. The computer then performs a power-on self-test (POST). The POST is a small computerprogram within the BIOS that checks for hardware failures. A single beep after the POST signalsthat everything's okay. Other beep sequences signal a hardware failure. The meaning of the beepsequence depends on the manufacturer of the motherboard type, while it means a keyboard erroron another.

3. The computer may display information on the attached monitor, showing details about the bootprocess. This information may include the BIOS manufacturer and revision, processor specs, theamount of RAM installed, and the drives detected.

4. The BIOS attempts to access the first sector of the drive designated as the boot disk. The bootdisk is typically the same hard disk or solid-state drive that contains your operating system. Youcan change the boot disk by configuring the BIOS or interrupting the boot process with a key

sequence (often indicated on the boot screens).5. The BIOS confirms there's a bootstrap loader, or boot loader, in that first sector of the boot disk,

and it loads that boot loader into memory (RAM). The boot loader is a small program designed tofind and launch the PC's operating system.

6. Once the boot loader is in memory, the BIOS hands over its work to the boot loader, which in turnbegins loading the operating system into memory.

7. When the boot loader finishes its task, it turns control of the PC over to the operating system.Then, the OS is ready for user interaction



The BIOS

The BIOS is an important part of your computer. It holds the configuration settings for a number ofimportant settings such as the boot order of your computer. By default your computer attempts to bootfrom the C drive unless it is an old computer that has a floppy drive which would then be the default.Suppose you want to install a new operating system on your computer from a DVD drive. You would openup the BIOS and configure the boot order so that the computer attempts to boot from the DVD drive first.Below is a screenshot showing the boot order configuration screen of a popular BIOS application.

Other things that you can do within the BIOS include but are not limited to the following.

Set or change a BIOS password. This is a password separate from the operating system. TheBIOS will not allow the computer to move forward through the boot process without it.

Change the CPU settings. A common setting to change is to turn on virtualization if the computerwill host virtual machines.

View the memory configuration of the computer.

In order to access the BIOS, you must press a designated key right after the POST check. The BIOSusually tells the user what key or keys to press on the upper right-hand corner of the monitor screen.Depending on the computer manufacturer, this key will be one of the function keys F1 or F2, the ESC keyor the DEL key. When you change settings, and attempt to exit, the BIOS will prompt the user to confirm ifhe or she wants to save the setting changes. If so, the computer will reboot again.

For a detailed list of the various BIOS manufacturers go to http://support.microsoft.com/kb/243909.

Although we have focused on the traditional PC desktop throughout this lesson, the concepts are prettymuch the same for laptops as well. Many of the components inside a laptop are physically integrated intothe laptop so it is mostly one piece of equipment. As far as tablets, most of the components with theexception of memory are non-upgradable and it isn’t cost-efficient to repair a tablet other than to trade itin.

c10j lesson 1 reading - the computer and its makeup

Documents