learn computers easily -(cdi) english speaking course lucknow -

8/8/2019 Learn Computers Easily -(CDI) English Speaking Course Lucknow - www.cdilucknow.blogspot.com

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COMPUTER COURSE - CDI

Confidence Fluency & Personality

www.cdilucknow.blogspot.com

L E A R N

C OM P U T E R S


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Dear Students,

Computers have brought about a revolution across all industries. They have changed the face of society.They are no longer specialized tools to be used by specially trained people. They are ubiquitous and usedin almost every sphere of life. Computers are the best means for storage and management of data; they canserve as huge knowledge bases and can be harnessed for all sorts of financial transactions owing to theirprocessing power and storage capacities. As computers are a daily utility, they have gained immenseimportance in day-to-day life. Their increasing utility has made computer education the need of the day.

By computer education, we mean, gaining the know-how of the basic concepts related to a computer and

gaining the basic knowledge of computer operation. Knowing about the basic components of a computer,the basic concepts behind the use of computers and the know-how of some of the elementary computerapplications constitutes computer education. Learning about the computer basics followed by a practicalexperience of using a computer is the key to computer education. As computers are widely used today,acquiring computer education is the need of the modern times.

Computer knowledge coupled with certain other job skills increases one's chances of getting a job. Thosewith knowledge of computers are considered trainable for many kinds of jobs. As most of the jobs involvethe use of computers, computer education is an eligibility criterion for almost all of the modern-day jobs.

Higher education involving network administration, hardware maintenance or software skills open doorsfor brighter job opportunities.

Computer education helps one manage one's own business assets and personal finances. Computers serveas efficient means for management of information. Personal financial assets, medical records and importantdocuments can be stored in an electronic format in a computer system. Today, banking transactions andpayments of bills can be done over the Internet. Similarly, online shopping is becoming widely popular. To be in the race, it is very important to take computer education.

Computers, which have such a wide variety of applications, are indeed ruling society. To keep up the pacein this fast life of today, computer education is extremely important. Computers are an integral part of lifeand so is computer education!

Thanks & RegardsBrij Raj SahaniAcademic Coordinator


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WHAT IS A COMPUTER?

A computer is often understood to be a device that

"Computes" or calculates numbers. A computerhowever, does more than that. It can edit text, generatepictures or graphs, translate languages, & even playgames.

What is the full form of computer?C = Common O = Operate M = Machine P = PurposeU = Used for T = Technology E = Education R =Research

A. Accept data supplied by the user B. Input, store and execute instructions C. Perform mathematical and logical operations D. Output results according to user requirements

Data

Capture Data

Manipulate Data

Output Results

Information

Data is raw material used as input and information isProcessed data obtained as output of data processing

What are the characteristics of a computer?A characteristic of computer is:

SpeedStorageAccuracy

DiligenceVersatility

SPEED : Computer performs complex calculation at avery high speed.

STORAGE : The storage characteristic of a computerhas made it distinct from calculates. A large amount ofdata can be stored in computers

MEMORY : The storing capacity of computer isexpressed in bytes.

1024 bytes = 1 kilo bytes.1024 kilo bytes = 1 Mega bytes.1024 Mega bytes = 1 Giga bytes.

ACCURACY : The result given by the computer will beextremely accurate. If a mistake occurs in anycalculation, they are due to manual errors likeFeeding wrong data or mistake in the instructionsgiven.

DILIGENCE : A computer is capable of performing therequired task repetitively, without affecting its speed.Accuracy and efficiently thus, it anycalculation is doneone or million times, the computer does it with thesame speed and accuracy. Unlinking the human beinga computer nevergets tired, bored, or lazy to do itstask.

VERSATILITY : The computer is versatile device. Ithas a wide range of application areas; they have beensuccessfully used in different areas like


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Education, science and technology, astronomy business etc.

CLASSIFICATION OFCOMPUTERS There are a huge number of computers availabletoday. The can be classified.

1. On The Basis Of Activity.2. On The Basis Of Volume.3. On The Basis Of Brand.4. On The Basis Of Model.

ON THE BASIS OF ACTIVITY: COMPUTERSMAY BE CLASSIFIED INTO:-

1. Analog computer.2. Digital computer.3. Hybrid computer.

ON THE BASIS OF VOLUME

1. Mainframe computer.2. Minicomputer.3. Micro computer.

ON THE BASIS OF BRAND

1. IBM pc.2. IBM compatibles.3. Apple/Macintosh.

ON THE BASIS OF MODEL

1. XT (extended Technology)2. PC/ AC (personal computer & advancetechnology).

3. PS/2 (personal system)

ANALOG COMPUTERS: Computers using signals as input are known asAnalog Computers. Thermometers, Speedometer etc.are the examples of Analog Computers.

HYBRID COMPUTERS: There is lot of applications, in which one wants toobserve the variations in the signals and according totheir variations; they have to take an action. HybridComputers are specially designed for an applicationand hence they are also called Special Purpose

Computers.

DIGITAL COMPUTERS: Computers, which accept Digits and Alphabet asinput, are known as Digital Computers. e.g.Computers used for business purposes, where data isentered in the form of Alphabets and Digits.There are various ways of classifying digitalcomputers but in this chapter we will discuss thefollowing two ways only:

MICRO COMPUTERS : 1) These computers have C.P.U. on a single chip. 2) They have low storage capacity up to a maximum of10 kilo words (1 kilo word = 1000 words)

3) These computers can accept and transfer data fromI/O devices at maximum speed of 5 lakh bites persecond.

4) These computers have a display unit as a cathoderay tube attached to them.


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5) These computers accept high-level languages Pascal,Fortran, Basic. The commonly used language of thesecomputers is Basic.

6) The maximum word length in these computers is16-Bits. However most of these computers use 8-bitswords.

7) They are quite inexpensive. The cost usually variesfrom 2 to 6 lakh rupees. Personal Computer in thesecategories have a very low cost up to a few thousandrupees. This factor has made Micro Computer ahousehold item.

MINI COMPUTER

Minicomputer is relatively larger, faster and expensivecomputer. They also use microprocessor as CPU butare designed to handle the processing needs of Multi-user environment. Hardware of minicomputer is notas standard as that of personal computers and variesfrom computer to computer. Here we describe thefacilities provided by the Mini Computer.

1) They are general-purpose computers but have asmaller size of Central

Processing Unit.

1) They have lower storage capacity. For example amini computer PDP-11 can store up to 2 Mega words.

2) They have hard disks for backing stores. Some minicomputers may use magnetic tapes for this purpose.

3) They can accept and transfer data from I/O devicesat the maximum speed of 4 million bytes per second.

4) They accept all types of High Level Languages.

5) The word-length in these computer is comparativelysmaller, usually 12 to 32 bits.

6) The cost of these computers varies from 6 to 25lakhs of rupees.

7) They can support a maximum of 20 terminals.Examples are PDP-11, Vase Range, Micro Galaxy etc.

MAIN FRAME COMPUTERS :

Mainframe use property circuits and are generallymore powerful then a typical mini computer. Similarto the mini computer main frame also does not haveany standard hardware. Here we will describe thefeatures of the main frame:

1) They are big general-purpose computers. These are

capable of handling all kinds of problems whetherscientific or commercial.

2) These have large storage capacities of millions ofwords. For example IBM370 can store up to 10 Megawords in its main memory.

3) The Main Frame computers have a large number of backing storage devices attached to them.

4) These computes can accept and transfer data fromI/O devices at the rate of millions of bytes (one byte =8 bits) per second.

5) The Main Frame computers can accept all types ofHigh Level Languages.

6) The word length in these computers is quite largeusually 32 to 64 bits.

7) The cost of these computers depends upon thefacilities required varies from 1 crore to 10 crorerupees.


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8) These computers can support a large number ofterminals say up to 100 or more. Examples are DEC10,IBM 360/370, and EC 1020, ICL1900/2900.

SUPER COMPUTERS :

Complex scientific and statistical applications likeweather forecasting, airflow simulations around eachpart of the aircraft need large amount of data to bemanipulated with in a very short time. This type ofrequirement cannot be met by main frames and stilllarge capability computers are required. Supercomputers meet these requirements.

Super Computers are multiprocessor systems in whicheach processor does parallel processing. They arecapable of executing multi million instructions persecond by harnessing hundreds of micro- sized

processor in parallel. Examples of Super Computer areCRAY XMP 23 and NEO 500

PERSONAL COMPUTER :

Most commonly used computers now days arepersonal computers. There are three categories ofPersonal Computers:

1. PC 2. PC/XT 3. PC/AT

PC

This is the smallest category of personal computer andconsists of following Hardware:

a) It uses INTEL 8088 microprocessor as main CPU,

INTEL8088 is an eight bit microprocessor

b) It has 256KB of main memory. This memory can beexpended to 640KB.

c) It has two 5 floppy drive.

d) It has one display unit which would either becoloured or monochrome (CGA or VGA)

e) It has one keyboard with numeric, alphabeticfunction key.

f) It has two RS 232C port for communication.

Personal Computers are single user computers and useMS-DOS as its operating system.

PC/XT :

Personal Computer using extended technology (XT) istermed as PC/XT. The only difference between PC andPC/XT is that PC/XT is supported by Hard Disk.Maximum two hard disks are supported by thesystem. When the data volumes are large and cannot be accommodated on floppies then one has to switchover from PC to PC/XT programs and software thatruns on PC can also run on PC/XT without any change

or modification.

PC/AT:


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Personal Computer that use advance technology (AT)are termed as PC/AT.PC/AT use INTEL 80286 as itsmicroprocessor. It also supports the same hardwarethat a PC and PC/XT support.

PC, PC/XT, PC/AT use the same operating system andare fully compatible with each other software that runson one computer can run on other computer alsowithout any modification or change.

PRIMARY STORAGE UNIT

The primary storage unit refers to the internal storageunit of computer, where programs and their data arestored. Primary storage provides temporary storageduring program execution. Part of primary storage

may also contain permanently stored instructions,such as those that tell the computer what to do when it

is turned on. Most primary storage today is comprisedof semiconductor technology.

RAM (Random Access Memory)

RAM is part of primary storage where data and

programs instructions are held temporary while beingmanipulated or executed. This type of memory allowsthe user to enter data into memory (write) and then toretrieve it (read).

RAM is volatile; it depends on a steady supply ofelectricity to maintain data storage. When the power tothe computer is shut off, everything that was stored inRAM is lost.

ROM (Read Only Memory)

As the name implies, Read Only Memory can only beread; data cannot be written into it. ROM may containinformation on how to start the computer and eveninstructions to the entire operating system. The actualcontents of ROM are usually set by the computermanufacturer, they are permanent.

FUNCTIONAL COMPONENTS OF ACOMPUTER


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Power Supply Central Processing Unit (CPU)

CD-ROM orDVD-ROM drive

Ports

Expansion

Cards

ExpansionSlots

Motherboard

Hard disk drive(HDD)

Floppy diskDrive

CD-ROM orDVD-ROM drive

On/Off switch

Power receptacle

Keyboard port

USB ports

Serial port (COM1)

Serial port (COM2)

Line-out (speakers/headphone)

Line-in jack

Microphone jack

Phone Jack

Mouse Port

Ethernet Connector

Parallel Port (Printer)

Joystick port

Wall Jack

Video Monitor


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BASIC PARTS

HARDWARE

The hardware is the part of the computer you can touchand see.(e.g. keyboard, mouse, monitor)

Physical components of a computer system, in the formof computer hardware.

The Monitor is the display screen, similar to atelevision screen.

The Computer, tower or case is the heart of thesystem. This is a box that contains all the parts thatmake the computer work.

The Keyboard is what you type on, similar to atypewriter.

The Mouse is the small hand held device that attachesto the computer. It may have two or three buttons. Themouse is used to move the cursor (pointer) on thecomputer screen.

A Floppy Disk (sometimes just called a disk) lookslike a plastic card that can be put into a slot in the frontof the computer. These disks hold information and can be used to exchange information between computers.

This type of data storage is archaic and obsolete.

SOFTWARE

The software is a part of the computer you cannot touch but is very important. The software is all theprogramming that makes the computer runs;controlling everything that the computer does.

System software

Operating System is the base program on a computer isconsidered system software. It tells the computer howto work or operate. The operating system also allowsyou to load other programs that do specialized tasks onto your computer. (ex. Windows XPand Vista)

Application software

Application software allows you to accomplish one ormore specific (non-computer related) tasks. Such ascomputer games for entertainment or Microsoft Wordfor typing.

Programming software

Programming software provides tools to assist acomputer programmer in writing programs andsoftware.


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A CD-ROM is very similar to a stereos CD player. Itnot only plays music but can also retrieve informationstored on CD's. It is also available in other formats suchas DVD-ROM

WHATS INSIDE A COMPUTER CASE? ITEM DESCRIPTION

MOTHERBOARD

The main piece of circuitry in a computer. Everythingconnects to or is wiredto the motherboard

CENTRAL PROCESSINGUNIT (CPU)

The computers brain or heart, the CPU is a computersmain chip. The CPUis really nothing more than an incredibly fast andpowerful calculate?

RANDOM ACCESSMEMORY (RAM)

A computers temporary storage place, where it gets itswork done. For example, when you use a wordprocessor to type a letter, the letter is storedIn the computers memory.

ROM-BIOS A computers ROM -BIOS (stands for Read OnlyMemory Basic

Input/output System) is a special chip with instructionsfor the computer to Communicate with other hardwareparts.


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EXPANSION SLOT

An expansion slot lets you add more features andcapabilities to a computer

by plugging in expansion cards.

EXPANSION CARD A card that allows you to expand your computerscapabilities, such as aModem card, a network card, a video card, or a soundcard.

PCMCIA CARDSNotebook computers are too small to use expansioncards, so they usespecial credit-card sized PCMCIAcards instead.You plug in a PCMCIA card,or PC Card, into a notebook computer to give it morefeatures and capabilities. Nobodys going test on this, but PCMCIA stands for PersonalComputer Memory Card International Association.

SOUND CARDA device that can reproduce almost any sound,including music, speech, and sound effects. A computermust contain a Sound Card in order to produce sounds.You can attach speakers and/or a microphone to thesound card.

MODEM Modem: A device that translates data from your PCinto a form that can be sent to other computers overregular phone lines. The modem also receives signalsfrom other computers and converts it into something

your computer can understand. A modem is the devicemost home computers use to connect to the Internet.

CD-ROM: (Compact D isk Read- Only Memory) Aremovable disk which can store large amounts ofinformation. Because it is Read-Only, new informationcannot be saved to it. Requires a CD-ROM drive (usuallycalled a D: drive ) to read the information . ACD-ROM can hold 650 - 800 megabytes of information,much more than a floppy disk can hold.

Some new Computers have a CD-RW (Compact D iskRew ritable) drive which allows the user to save

CD-ROM CD-ROM or CD ReWritable Drive


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information onto a CD. This is done with lasers in aprocess called burning. Once the information is savedonto the CD, it can be read on any CD-ROM drive.

HARD DRIVEHard Drive : The main storage area inside yourComputer (usually called a C: drive). The hard disk orhard drive stores your computer's operating system, thePrograms that are installed on your computer, and mostof your files. Hard drive capacity is measured ingigabytes.

POWER SUPPLYThe power supply converts the alternating current (AC)line from your home or school to the direct current(DC) needed by the computer.You can see the power supply from the back of yourcomputer because of the power cord and the cooling

fan.Computers put out a LOT of heat and need the fan tokeep them from overheating.

NETWORK INTERFACE CARD A NIC card (Network Interface Card) allows yourcomputer to talk to other computers! A cable calledCat5 is plugged into the NIC card and your computercan then be attached to a network and be on theinternet!

BIOS CHIP A BIOS chip (Basic Input Output System) is a veryimportant computer component. In simple terms, theBIOS chip wakes up the computer when you turn it onand reminds it what parts it has and what they do!

INPUT & OUTPUT DEVICES


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INPUT DEVICES

An input device is a hardware device that sendsinformation into the CPU. Without any input devices acomputer would simply be a display device and not allousers to Interact with it, much like a TV. Some of thecomputer input devices are as follows.

OUTPUT DEVICES

These devices display and generate information thathas been held or generated within a computer. Someexamples are shown below.

DIGITAL CAMERA

Digital camera is a type of camera that records andstores pictures or videos. Themain feature of digitalcamera is theability to take dozens, sometimesHundreds of different pictures.

MONITOR

It is a video display screen and the hardShell that holds it. It is used to visuallyinterface with the computer and areSimilar in appearance to a television.

JOYSTICK

Joystick is an input which allows anindividual to easily navigate an object ina game such as navigating a plane in aFlight simulator.

PRINTER

It is an external hardware deviceresponsible for generating a hard copy ofData. It is commonly used to print text,Images, photos, etc.

KEYBOARD

One of the main input devices used on acomputer, a PC's keyboard looks verysimilar to the keyboards of electricTypewriters, with some additional keys.

SPEAKER

It is a hardware device connected to a computer'ssound card that outputs Sounds generated by the card.

MICROPHONE PROJECTOR


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It is the hardware device that allowscomputer users to input audio into theirComputers.

It is a device that enables an image, such as a computerscreen, to be projected onto a flat surface. Thesedevices are Commonly used for presentations.

MOUSE

It is an input device that allows anindividual to have the ability to performvarious functions on computer such as

Opening a program or file.

PLOTTER

It is a device that draws pictures on paper based on commands from a computerUsing a pen. Multicolor plotters use

different-colored pens to draw differentColors.

SCANNER

It is a hardware input device that allows a

user to take an image and/or text andconvert it into a digital file, allowing thecomputer to read and/or display theScanned object.

DISK DRIVES

A disk drive is used to record information from the

computer onto a floppy disk or CD.

WEB CAM

It is a camera which is connected to acomputer to allow a person to view otherPeople, places, and even events.

FLOPPY DISK

A floppy disk is used to record information on. Theinformation is stored on the floppy disk and can beused later or used on another computer.


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TOUCH PAD

A touch pad is small, touch-sensitive pad used as apointing device on some portable computers. Bymoving a finger or other object along the pad, you canmove the pointer on the display screen.

HEADPHONES

Headphones give sound output from thecomputer. They are similar to speakers, except theyare worn on the ears so only one person can hear theoutput at a time.

ACCU POINT POINTING DEVICE

An Accu point Pointing Device, or pointing stick, isanother mouse substitute that is found on many laptopcomputers. An Accupoint Pointing Device usuallySits in the middle of the keyboard and resembles aneraser at the end of a pencil.

MICROFILM (COM)

Computer Output Microfilm. The computerdirectly generates the microfilm images.

TRACK BALL

A track ball is essentially a mouse lying on its back. Tomove the pointer, you rotate the ball with your thumb,your fingers, or the palm of your hand.

SOUND CARD

Also known as a sound board or an audio card, asound card is an expansion card or integrated circuitthat provides a computer with the ability to producesound that can be heard by the user either overspeakers and/or headphones .

LIGHT PEN VIDEO ADAPTER
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A light pen is input device that utilizes a light-sensitivedetector to select objects on a display screen. A light penis similar to a mouse, except that with a light pen youcan move the pointer and select objects on the displayscreen by directly pointing to the objects with the pen.

Also known as a graphics card, video card, video board, or a video controller, a video adapter is aninternal circuit board that allows a display device suchas a monitor to display a picture from the computer.Today video cards are most commonly connected tothe AGP, PCI, or PCIeexpansion slot on themotherboard, however, can also be found on-board.

SCANNER

A scanner is a lot like a photocopier. Instead ofproducing copies, a scanner converts images into digitalinformation and stores it in a computer.

WHATS ON THE BACK OF A COMPUTER CASE? PORT Icon DESCRIPTION

Keyboard & Mouse

The keyboard and mouse jackslook identical on most PCs, so lookfor colors and icons to help youwith plugging in these devices.

Some mice and keyboards use USBports. Older mice may use a serialport.

Serial (or COM) ports are a veryversatile type of port.Some of the things you can pluginto a serial port include:
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Serial or COM

a mouse, modem, scanner, ordigital camera. MostComputers have two serial ports:COM1 and COM2.

Parallel or Printer

You plug your printer into(surprise, surprise) the parallel(or printer) port. Many newerprinters may use a USB port

USB

Designed to replace older Serial

and Parallel ports, the USB(Universal Serial Bus) can connectcomputers with a number ofdevices, such as printers,keyboards, mice,Scanners, digital cameras, PDAs,and more. Better yet, the USB portsupports plug-and-play

Video or Monitor

You plug your monitor into thevideo port.

Line Out

Plug in your speakers orheadphone into the Line Out jack.

Line In

The Line In jack allows you tolisten to your computer using astereo system.

Microphone

You can plug a microphone into

this jack to record soundsOn your computer.


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Joystick or Game

If you have a joystick, musical(MIDI) keyboard, or othergaming device, this is where youplug it in.

Phone or Modem

The phone or modem jack iswhere you plug your computerinto a phone line.

Network or Ethernet

You can connect your computer toa network by pluggingin an Ethernet cable in this port.

SCSI

A SCSI port is one of the fastestways to connect a hard Drive, CD-ROM drive, or other device to acomputer.

CENTRAL PROCESSING UNIT (CPU)


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CPU is the brain of the computer while others describe it as the heart. Inany case, its the thing that makes

your computer a computer. The CPU does all the work:It calculates, it processes, it keeps things runningsmoothly

The CPU is also known as the computer chip (because thats what it is) or the microprocessor(or processor , forshort).

Intel makes most CPUs. In fact, Intel is the company that came up with the name Pentium. However, AMDand VIA Technologies are two other well-known CPU manufacturers. Their CPUs are less expensive and usea different naming system (such as the AMD Athlon and the AMD Duron). Intel actually makes a lessexpensive version of the Pentium as well, which it calls the Celeron. The Celeron does what the Pentium does, but not as quickly.

Speaking of which, speed is what the CPU is all about, and each successive version of the CPU getsprogressively faster. A CPUs speed is measured in megahertz (MHz) or, for newer models, in gigahertz(GHz). A megahertz equals millions of cycles per second; a gigahertz equals billions of cycles per second.Higher numbers equate to higher speeds. You might see an Intel Pentium 4 at 3.06 GHz, a Pentium III at 1.40GHz, and a Celeron at 2.20 GHz.

Another common measure of a CPU is how many bits it can handle at a time. A bit is the tiniest piece ofinformation processed by a computer? Eight bits make up one byte, and one byte equals one character.Computers used to handle 8 or 16 bits; now theyre up to 32 and 64 at a time. Dont worry if all of this seems

a bit confusing well cover bits and bytes in greater detail in a later lesson.

C.P.U SPEED DESCRIPTION

CENTRALPROCESSINGUNIT (CPU)


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1 GHz to3 GHz

Intel Pentium 4 Processor

The Pentium 4 is Intels more recent andfastest generation of CPUs, with processingspeeds over 3 GHz.

450 MHz to1 GHz

Intel Pentium III Processor

Launched in 1999, Pentium 3 CPUs are stillfound in some newComputers.

1.06 to2 GHz

Intel Celeron Processor

Intels Celeron CPU is an inexpensiveprocessor designed for people on budget.Celeron processors are very similar toPentium processors, but they have less built-in memory.

500 MHz to3 GHz

Intel Xeon Processor

Dont expect to see any Xeon -basedcomputers at your local computerStore its designed for high end servers.

850 MHz to1.67 GHz

AMD Athon Processor

The Athlon processor is equivalent toPentium processors only its Lesson expensive.

700 MHz to800 MHz

AMD Duron Processor

The Duron CPU is AMDs is similar to IntelsCeleron processor. It hasLesson built-in memory and is designed forpeople on a budget.

QUICK REFRENCE

The CPU, or CentralProcessing Unit, is theComput ers main chip. It calculates and processes

Information.

CPU Speed is MeasuredIn:

Megahertz (MHz).

Gigahertz (GHz).

Common CPUs Include: Intel Pentium III Intel Pentium 4 Intel Celeron

AMD Athlon AMD Duron


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MEMORY

Computeronly underst ands the concept of on and off. On is represented by the number one (1); off is represented

by the number zero (0).

Everything that a computer does is based on thiscombination of ones and zeros, which is known as the binary system.These ones andzeros are digits, known as bits , which are the smallest memory unit. The term bit is shortfor binarydigit.

The second thing you need to know is that a computer saves information in bytes , not bits. So what is a byte? Theterm byte is short for binary digits eight . So, one byte is made up of eight bits. And a byte is the equivalent of acharacter, which can be a letter, a number, or a symbol.

The next largest unit is the kilobyte. A kilobyte (abbreviated K or KB) equals 1,024 bytes or characters.

After the kilobyte, the next largest unit is the megabyte. A megabyte (abbreviated M or MB) equals 1,048,576 bytes orcharacters.

The next unit after the megabyte is the gigabyte. A gigabyte (abbreviated G or GB) equals 1,073,741,824 bytes orcharacters.

Finally, after the gigabyte comes the terabyte. A terabyte (abbreviated T or TB) equals 1,099,511,627,776 bytes orcharacters.

BITS AND BYTES UNIT ABBREVIATION SIZE SYMBOL EQUIVALENTBit - - An atom or speck,

the smallest unit ofmemory

Byte - 8 bits A single letter, aNumber or asymbol.

Kilobyte K or KB 1,024 bytes A one-page, doublespaced letter.

Megabyte M or MB 1,048,576 bytes A best-selling novel.

Gigabyte G or GB 1,073,741,824 bytes An encyclopedia set.


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Terabyte T or TB 1,099, 511,627,776Bytes

A bookstore.

RAM and ROMRAM ROM

When someone at a computer superstore tells you howmuch memory a new computer has, theyre reallytalking about RAM. RAM is the computers mainmemory, which it uses to process information.Whenever you work with a file onYour computer,youre using RAM. And the data in that file istemporarily stored in RAM.

However, RAM is volatile , which means that the data isstored only as long as the computer has power. Onceyou shut off your computer, the data is gone.

However, you can and should save your data (read:your file). Thats where storage comes in, but more onthat later. For now, think of RAM like a notebook: You

can read from it and write to it. Technically, it could becalled read and write memory.

Random-access memory

Main memory.

Necessary to process information (example: workWith a file).

Volatile : If not saved, data disappears when you

Shut off the computers power. Its temporary.

Often discussed when buying a computer.

You can read from and write to it. Comparable to aNotepad.

ROM is the computers low -level memory, which ituses to perform its most basic functions. This memoryis permanent; the data remains even if you shut off thecomputer. This only makes sense because ROM isrequired to restart your computer.

You never hear people discuss how much ROM youhave because the manufacturer usually installs it, andyou never touch it. It does all the behind-the-sceneswork and then disappears once youre underway,much like a party planner.

You can also think of ROM like a novel: You can readfrom it, but you cant write to it.

Read-only memory

Low-level memory.

Necessary to perform the most basic functions(Example: start the computer).

Nonvolatile : Data remains even when you shut off the

computers power. Its permanent.

Seldom mentioned when buying a computer.

You can read from it, but you cant write to it. Comparable to a novel.

QUICK REFRENCE

Computers have two typesof memory:

Random-access memory(RAM). Read-only memory

RAM: Computers main memory, which

is used to process information(Example: work with a file). Volatile: Unless saved, data

ROM: Computers low -level memory,

which is used to perform its most basic functions (example: start thecomputer).


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(ROM). disappears when you shut offcomputer. You can read from it and write toit. Comparable to a notebook; youcan read and write to it.

Nonvolatile: Data remains evenwhen you shut off computer. Itspermanent. You can read from it, butyoucant write to it.Comparable to anovel;you can only read it.

KEYBOARDKeyboard is an input device that allows you to talk to the computer. The keyboard is easily recognizable because itresembles a typewriter keypad.

KEY DESCRIPTION

ALT KEY The key doesnt do anything by itself it needsanother key to make things happen.

For example, pressing the key while holdingdown the key switches between any programsthat are currently running.

CTRL KEY Just like the key, the doesnt do anything by itself you need to press another key with it to makethings happen. For example, pressing the key whileholding down the key cuts whatever is selected.


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F1 KEYThe key is the help key, and pressing it displayshelpfulInformation about what youre doing.

ESC KEY The (Escape) key is the Wait, Ive changed mymind key and is the same as clicking Cancel in a dialog box. For example, if you click something and anunfamiliar dialog box appears, you can close it bypressing the key.

ENTER The key is the Carry out my orders key and isthe same as clicking the OK button in a dialog box. Forexample, after youve typed the name of a program youwant to run in a dialog box, press to run the program. The key also addsnew lines and starts new paragraphs if youre enteringtext.

TAB When youre in a dialog box, pressing the keymoves to the next field. When youre using a wordprocessor, the key works just like youd think itwould and jumps to the nearest tab stop whenever youpress it.

ARROW KEYS (LEFT, RIGHT, UP, AND DOWNARROW KEYS)

The arrow keys move your computers cursor across thescreen.

DELETE Nothing surprising here. The key deletes orerasesWhatever you select files, text, or graphical objects. Ifyoure Working with text, the key erases characters tothe right of the insertion point.

BACKSPACE Use the key to fix your typing mistakes iterases

Characters to the left of the insertion point.


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HOME The key jumps to the beginning of the currentline when youre working with text.

END The key jumps to the end of the current linewhe n youre working with text.

PAGE UP The key moves up one screen.

PAGE DOWN The key moves down one screen.

DIGITAL CAMERAS & WEB CAMSA digital camera lets you take pictures that you can transfer to a computer. Once yo uve transferred your picturesyou can print them, insert them in word processing document, or send them in an e-mail message. You can also editdigital photos, to remove such undesirable objects as redeye or an ex-boyfriend

The quality of the pictures a digital camera takes depends on its resolution, which is measured in megapixels. Onemegapixel is equal to one million, or 1000 1000 pixels. The higher the number of megapixels, the clearer and moredetailed the picture

Digital cameras dont use film they store their pictures on a type of removable memory called flash cards. Flashcards can store anywhere from a dozen to several hundred pictures, depending on how much memory they have.There are three different types or formats of flash cards out there:


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Compact Flash: Definitely the mostcommon type of digital film out There, Compact Flash cards canstore anywhere from to 1GB ofmemory.Compact Flash sizes range from 8MB all the way up to 1 GB!

Smart Media: Smart Media isanother a very popular type ofmemory cardBecause of its small size. SmartMedia cards are also widely used inmany PDAs.Smart Media cards are available incapacities ranging from 2 MB to 128MB.

Memory Stick: Sony makes its thistype of memory card for use in itsOwn products; Sony digitalcameras, Sony PDAs, etc. Memorysticks are available inCapacities ranging from 4 MB to 128MB.

MONITOR

A computers monitor looks and works a lot like a TV screen. The monitor is really only half of makes text andimages appear on the screen. The other half is the graphic card, or video/display adapter. The monitor plugs into thegraphics card in the back of the Computer.

CRT MONITOR TFT MONITOR

A flat panel monitor is the same type of display that is found in laptop computers. Flat panel monitorsare thin,lightweight, and use a lot less electricity than traditional monitors. Flat panelmonitors are also considerably moreexpensive than traditional monitors, although theprice is dropping. Flat panel monitors are wider than traditionalmonitors are; in fact a 15-inch flat panel monitor has almost the same viewing area as a 17-inch traditional monitor

SIZE

The size of a monitor is measured diagonally across the screen, just like TVs. Common monitor sizes are 15, 17, 19,and 21 inches. The most popular monitor size is currently 17 inches.

DOT PITCH

Dot pitch refers to the distance between each pixel, or dot, on the screen, as measured in mill imeters (mm). Thesmaller the dot pitch, the closer the dots, and the sharper the image is. If youre in the market for a monitor try to findone with a 0.28 mm or less.


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REFRESH RATE

The refresh rate determines how quickly the monitor redraws, or updates, the image on the screen. Higher refreshrates are better, since they flicker less and are easier on the eyes. The refresh rate is measured in hertz (Hz), or thenumber of times perSecond the monitor redraws the entire screen. If youre buying a new moni tor, make sure to get one with a refreshrate of 72 Hz or better.

SCREEN SAVERS AND ENERGY STAR COMPLIANCE

A screen saver is a moving picture that appears on your computer screen when you dont use your computer for awhile.

Most monitors are Energy Star compliant. This means they automatically turn themselves off after a period of time tosave electricity. You turn the monitor back only by simply moving the mouse or pressing a key on the keyboard.

GRAPHICS CARD

The second part of a computers vi deo system is the graphic card or video adapter. A graphics card is an expansion

card that plugs into a computers motherboard and is responsible for all the text and pretty images that appear onyour computers monitor.

Many computers dont have a graphi cs card at all all the video capabilities are instead built into the computersmotherboard.

Graphics cards come in many models and prices. More expensive graphics cards are faster and can display morecomplex, 3D graphics something especially useful if y oure into computer games. Here are the basics about graphiccards:

SCREEN RESOLUTION

Resolution has to do with how much information can fit on the computer screen. Obviously you cant adjust howlarge or small your computers monitor is (without buying a new one that is), but you can make all the images on


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your screen larger or smaller so you can see more information at once. You can adjust the screen resolution to suityour needs and preferences.

COLOR DEPTH

Color depth is the number of colors that are displayed on the screen at once. So why would you want to change thenumber of colors displayed on your screen? Perhaps you want to use higher color depth settings to make videos andphotographs more realistic. Or some finicky games also require you to use a specific color depth.

GRAPHICS CARD MEMORY

Graphics cards have their own memory, or RAM, just like a computer. Youll need more memory to display higherscreen resolutions and color depths. Video cards can have anywhere from 1 MB all the way up to 128 MB of memory.If youre buying a new computer make sure it has at least 64 MB of memory.

3D GRAPHICS ACCELERATOR

A 3D graphics accelerator card has its own CPU that is used to create 3D graphics. If youre even considering playingany games on your computer you should have a 3D graphics accelerator card, as most newer games require one.

COMMON SCREEN RESOLUTIONResolution Description

640 by 480

No longer supported in most computers , 640 by 480use to be the lowest resolution setting. Larger andcheaper monitors have made 640 by 480 resolutionseffectively obsolete.

800 by 600

This has been the standard resolution setting for mostcomputers, and is the lowest setting on newer monitors.This is a good in-between resolution, allowing you todisplay quite a bit of information on the screen withouthaving to use a magnifying glass to read it. Use thissetting if you have a 15-inch or17-inch monitor.


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1024 by 768

The new standard, 1024 by 768 puts a lot of informationon your screen, but the images can start getting smalland difficult to read at this point (unless you have alarge monitor). Use this setting if you have a 17-inch orlarger monitor or when you want to see a lot ofinformation at the same time, for example ifYoure working on a large spreadsheet, graphic files, ormultiple windows.

Higher Resolutions

Depending on how expensive the graphics card in yourcomputer is, there may be several higher modes of

resolution which continue to display more and moreinformation and smaller and smaller images.

COMMON COLOUR DEPTHS

Color Depth Description

256 Colors

No longer supported on many computers , 256 colorswas the standard color depth years ago, but mostcomputers and video cards are fast enough to run withMore colors without taking a performance hit, makingthis color depth almost obsolete.

16-bit

16-bit color displays roughly 65,000 colors at once. Thisis the point where pictures become photo-realistic. This

is a good color depth setting because it can displayphoto-realistic images without slowing your computerdown. You have to really squint to see much difference between 16-bit color and higher levels of color depth.

24-bit

24-bit color displays 16.7 million of colors at once.Depending on how expensive the graphics card in yourcomputer is there may be several higher modes of colorDepth, which continue to display more and more colorson the screen.


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32-bit

32-bit color displays 16.7 million of colors at once. 32-bitcolor is faster and moreEfficient than 24-bit color.

PRINTER BASICS

A printer is an output device that puts text and graphics on paper. Using the printer is often the last step in creatingsomething on a computer, whether its a letter, spreadsheet, or digital photogr aph.

Things to know before purchasing a printer

TYPE OF PRINTER

There are several different types of printers out there: Inkjet and Laser printers are the most common. Inkjet printersare the cheapest and most common type of printer and can be found in both homes and businesses. Laser printers areusually faster than Inkjet printers, but they normally can only print in black and white. Laser printers are usedmainly by businesses.

COLOR VS. BLACK AND WHITE

Color use to be an expensive option for printers, but not anymore. Most Inkjet printers can print in color and so canan increasing number of laser printers. Most laser printers still print in black in white great for text but not forimages and graphics.

RESOLUTION

A printers resolution helps d etermine the quality of the images it can produce. Higher resolution means higherquality images. Printer resolution is measured in dots per inch (dpi). Generally, 600-dpi resolution works great fortext documents, while you will probably want 1200 dpi or better resolution for printing images.

300 dpi 600 dpi


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300 dpi 600 dpi

SPEED

A printers speed determines how quickly it can print pages. Speed is measured two ways: in characters per second(cps) or in pages per minute (ppm). Either way you want a higher number if you want to have a faster printer.Printers usually slow down quite a bit when printing pages with a lot of complicated graphics, or color images.

INK CARTRIDGES AND TONER

Today many Inkjet printers are cheap about as much as dinner for two at a very fancy restaurant. Sound too goodto be true? Heres the catch: the ink for most printers costs a lot of money. Inkjet printers use ink cartridges that seemto run dry at an alarming speed. Laser printers user toner cartridges filled with the same messy black powder that isfound in copy machines. Laser toner cartridges last a lot longer than Inkjet cartridges, but they also cost significantlymore.

MEMORY

Laser printers have their own memory, or RAM, just like a computer. This memory is used to store pages before theyare printed. Memory is important for printing complex or high-resolution images. Most laser printers have anywherefrom 2 MB to 8 MB of memory.

PRINT BUFFER AND SPOOLER

Computers are a lot faster than most printers are, so they can send information faster than the printer can accept it. Aprinter buffer or spooler fixes this problem. A print buffer works like a dam: it holds back the information andreleases it at a rate that the printer can handle.

TYPES OF PRINTERSPRINTER TYPE DESCRIPTION

INKJET PRINTER

Inkjet printers are easily the most popular andinexpensive type of printer out there. If you have aprin ter for your home computer, chances are its anInkjet printer. Inkjet printers create images by sprayingink onto a page. The inexpensive Inkjet printer gets itsink from very expensive Inkjet cartridges. Most Inkjetprinters can print in color, and their speeds vary from 2to 16 pages per minute (ppm).

Laser printers have blazing speed anywhere from 4 to


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LASER PRINTER

20 pages per minute (ppm), great resolution anywherefrom 300 to 1,200 dots per inch (dpi), and recently has become relatively inexpensive. Laser printers are greatfor businesses and people who need to produce largeamounts of text documents or correspondence.

Laser printers use the same technology as photocopymachines to create images blank and white images onpaper. Laser printers use powdered black ink, calledToner, just like photocopy machines do. When the tonercartridge runs out, you have to replace it with a newtoner cartridge. Toner cartridges cost a lot moreThan Inkjet cartridges do, but they also last a lot longer.

COLOR LASER

A color laser printer works just like an ordinary laserprinter, except that it can print in color, of course. Colorlaser printers are quite expensive and the color tonercartridges for them are even worse.

MULTIFUNCTION

As its name implies, a multifunction printer canperform more than one task. Multifunction printers canusually operate as a fax machine, copier, and scanner inaddition to their traditional printing duties.

Popular in the 1980s, noisy dot -matrix printers havegone the way of the dinosaurs, except in businesses thatneed to print on carbon copies. Dot matrix printersusually use a type of paper with holes punched alongeach side called continuous form paper, and load itthrough something called a tractor feed.

Dot-matrix printers range in speed from 25 to 450characters per second (cps), or 1 to 18 pages per minute(ppm).


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DOT MATRIX

Resolution is measured differently with dot-matrixprinters. Instead of using dot per inch (dpi) dot matrixresolution is measured by how many little pins are onthe dot-matrix print head. Dot-matrix printers areavailable with 9-pin (terrible quality) and 24-pin (higherquality) print heads.

PLOTTER

Dont expect to find a plotter at your local computerstore. Plotters are special, very expensive printers thatare used to create posters and blueprints.

SOUND AND SPEAKERS

The term sound card is a little misleading; sounds cards used to be expansion cards that plugged into a computersmotherboard. Although such sound cards still exist, today most computers have sound capabilities built-it to their

motherboards. Either way, a sound card basically does two things: play and record digital sounds.

The types of sounds your computer can play range from the sounds you hear when you turn on your computer, toexplosions in a computer game. A sound card can also play MP3 music files. An MP3 is a highly compressed soundfile that lets you play CD quality music on your computer.


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MODEM

Just about every new computer comes with a built-in modem. A modem translates a computers ones and zeros intoaudio tones, so that it can transmit information over the phone lines to other modems. The speed of a modem ismeasured by fast it can transmit information in bits per second (bps). Modems can be either internal or external

INTERNAL MODEM EXTERNAL MODEM

Most computers have an internal modem, Internalmodems often plug into an expansion slot and arecheaper thanExternal modems.

An external modem, plugs in to a computers serialport. Newer, broadband modem may plug into the USBor Ethernet port. A broadband modem transmitsinformation directly over a connection, unlikeOlder traditional modems that have to convert theinformation to tones or sounds first. Because of this, broadband modems are very, very fast much fasterthan Standard modems. DSL and Cable are the mostcommon types of broadband Connections.

Heres a quick overview of the major types of modems that are available:

Type Speed (in bps) Description

Standard 56K Standard modems connect to astandard telephone line and areused for dial-up connections to theInternet.

ISDN56K to 128K

One of the older broadbandconnections. Its only twice as fast as

a traditional modem and prettymuch obsolete.

DSL 256K to 6,000K DSL modems take advantage ofunused frequencies in the phoneline, such as a pause inconversation. DSL modems are veryfast;

Cable 640K to 4,000K A cable modem is the fastestmodem you can buy for home use.The problem is your cable company


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has to offer cable Internet access inorder to use it.

HARD DRIVE

A hard drive or hard disk is a computers main storage device. Most hard drives put in the system unit of a computerand hidden from view. Although you normally cant see a computers internal hard drive you can usually hear itwhirring Inside when you start the computer or a program. An external hard drive sit outside the computers systemunit and plugs into a USB, Fire wire, or SCSI port.

The hard drive is like the file-cabinet portion of your desk. And files really are saved in folders on a computer, so thisreally is the perfect analogy. Most computers have a single hard drive located inside of the computer case labeled C.When a computer has more than one hard drive they are labeled D, then E, and so on. Unlike RAM, a hard driveretains its Information even when you turn the computer off.

So whats stored on a hard drive? Lets take a look

OPERATING SYSTEM FILES

A computers operating system, like Windows XP, is stor ed on the hard drive.

PROGRAM FILES

Program files are the programs you work with, like your word processor, your Internet software, or your games.Programs usually come on floppy disks or CDROMs, to use it first install, or copy, it to your hard drive i n order to

use the program.

DATA FILES


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Whenever you create a document or data file on your computer, like a word Processing document, the computerstores it in its temporary memory (RAM.) You must save your documents to the hard drive or they will be lost whenyou turn off your computer.

Most hard drives are connected to a computers motherboard through something called an IDE (Integrated DriveElectronics) connection. You can also connect CD-ROM and DVD drives to an IDE connection. A slight problem withIDE is that it only supports a total of four devices or drives. This isnt a big deal for most home users, but it is ifyoure a Business and need a server with lots of hard drives. So theres another way to connect hard drives to acomputer: through a SCSI (pronounced get this scuzzy) port. SCSI connections are often faster than IDE and theycan connect up to seven devices instead of four.OK, so what else do you need to need to know about hard drives?

HARD DISK SIZE (OR CAPACITY)

How much information (how many programs and data) a hard drive can store is measured in bytes, just like RAM.Hard drive sizes in newer computers range from 20 Megabytes (MB) all the way up to 200 Gigabytes (GB)! How big ahard drive should you get when you buy a computer? Norma lly try to get at least 40 Gigabytes if youre a home orsmall business user. More is better in hard drives, because programs keep getting bigger.

AVERAGE ACCESS TIME

A hard drives average access time is how fast it can find information. Average access time is measured inmilliseconds (ms), or 1/1000 of a second. The lower the access speed, the faster the hard drive. Most newer computerhave an average access time of8 to 15 ms.

QUICK REFRENCE

Speed: Very fast. Most hard diskshave an average access speed of between 8 to 15 milliseconds (ms).

Capacity: Enormous. Many harddisks have more than 200 Gigabytes(GB) of storage.

Cost: Hard disks are becoming moreand more inexpensive. Byte for bytethey are the mostinexpensive way tostoredata.

Unlike floppy disks and CD-ROMs,most hard disks reside inside of thecomputer or system unit and cannot be easily removed.

A computers main storage device, usuallyLabeled C.

Modern hard drives canstore anywhere from20GB to 250GB ofInformation.

Average access time is how fast ahard drive can Find information.

Hard drives are connected to acomputer through either an IDE orSCSI interface.

Speed: Very fast, though normallyslower than internal hard disks.

Capacity: Enormous same asinternal hard disks.

Cost: Slightly more expensive thaninternal hard disks.


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HARD DRIVE MAINTENANCE

Cars require maintenance to keep them running at their peak performance. Some car Maintenance tasks are simpleand routine, such as changing oil every 3,000 miles. Others are more complicated, such as installing a new radio.Hard drives are no different they require routine maintenance to prevent and/or correct problems and to keep themrunning at their best performance.

How does one maintain a hard drive? Ther e are quite a few ways:

REPAIR A HARD DRIVE

Over time, hard drives can become damaged, affecting their performance. Fortunately most of the hard drive damageis caused by normal wear and tear is not serious. You can diagnose and correct most hard drive problems with a harddrive repair program. Microsoft Windows comes with a built-in hard drive repair program.

DEFRAGMENTING A HARD DRIVE

Normally a computer stores a file in the same location on a hard drive. Over time, ahard drive can become fragmented ,and instead of storing a file in the same locationit begins storing parts of it all over. When the computer needs to reada fragmentedfile, it must read several different parts of the hard drive instead of just one.Defragmenting a hard drive puts the fra gmented files back together in one place. Youshould your computers harddrive about once a month.

BACKING UP A HARD DRIVE

A computers hard drive keeps information even when the computer is turn off, butyou still should backup thedocuments you create to some type of removable storage,like a CD-RW or tape backup. This will give you an extracopy of your files in caseyour hard drive becomes damaged.

VIRUS PROTECTION

A computer virus is actually a small computer program written by a malicious personwith the purpose ofvandalizing computers by erasing information on their hard driveand causing other problems. Anti-Virus programs


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that protect computers againstviruses, like Norton Antivirus or McAfee Virus Scan, are available at most computerStores. If you even thinking about connecting to the Internet, and if you have acomputer you probably are, you needto have Antivirus software installed on yourcomputer.

HARD DRIVE COMPRESSION

A computer can increase space on a hard drive by using a special program tocompress, or squeeze together, the filesstored on a hard drive. Most datacompression programs can effectively double the amount of information a harddrivecan store. Sounds great, so why dont many people use disk compression? First, datacompression sl ows yourhard drive because the computer has to uncompress filesbefore it can read them. Second, data compression oftencauses more problems inhard drives. Third, several programs wont run on computer with compressed harddrives.Dont compress your hard d rive unless you absolutely have to, and even thenit might be better to start looking for anew, larger hard drive than to use datacompression.

CD-ROM DRIVE

CD-ROM Speed Transfer Rate8x 1,000 KB/s

10x 1,600 KB/s12x 1,800 KB/s16x 2,400 KB/s24x 3,600 KB/s32x 4,800 KB/s40x 6,000 KB/s48x 7,200 KB/s60x 9,000 KB/s

Another type of drive almost all computers have is a CD-ROM drive (CD-ROM standsfor Compact Disc-Read OnlyMemory). CD-ROM drives play CD-ROM discs the samekind of compact discs you can play in your stereo system.

CD-ROMs can store lots ofinformation: a single CD-ROM can hold more than 600 Megabytes (MB) of data morethan an encyclopedia set! Unlike a hard drive, most CD-ROMs can only readinformation you cant save, orrecord anyth ing on them (thats what the ROM in CDROMstands for: Read Only Memory!)

On the other hand, CD-RW drives can read andwrite (or burn) to special CD-R and CD-RW discs (the RW in CD-RWstands for Rewritable.) The CD-ROM drive is usually labeled D on most computers.

The speed of a CD-ROM drive determines how quickly the computer can readinformation stored on the CD-ROM.The faster a CD-ROM drive spins, the faster yourcomputer can run programs, and the better the programs will runand videos and soundwill be.

The original CD-ROM drive was no faster than an audio CD player, so the speedof all subsequent CD-ROM drives ismeasured by how many times faster they are thanthe original, 1x CD- ROM drive. Todays CD -ROM drives are up tosixty times (60x)faster than original.

Here are some things you can do with CD-ROMs:

INSTALL PROGRAMS

More programs are coming on CD-ROMs because of their large storage capacity. Instead of installing and copying 20


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floppies to your hard drive, you only have to install a single CD-ROM.

RUN CD-ROM PROGRAMS

CD-ROM-based programs are usually the coolest programs available for your computer. CD-ROM programs oftenhave rich, exiting multimedia content: high quality sounds, music, videos, and animations. For example, a popularCD-ROM program is a complete, searchable encyclopedia set which contains high quality pictures, sounds, music,and videos.

PLAY AUDIO CDS

Most CD-ROM drives are capable of playing audio CDs the same kind your stereo uses! So your computer can playmusic while you work.

TYPES OF CDS

CD Type Description

CD-ROMThe original, standard CD, CD-ROM stands forCompact Disc, Read-Only Memory. What this means isthat you can only read information from a CD-ROM;you cant add new information in a way.

CD-R If you have a CD-RW drive you can permanently storeinformation on a CD-R (Compact Disc-Recordable) disc.

The information you write or burn to a CD-R ispermanent and cant be changed or erased.

You can also use CD-R discs to create musical CDs thatyou can listen to in a stereo system.

CD-RW Unlike CD-R discs, a CD-RW (Compact DiscRewritable) disc can be written to many times. You canalso modify and erase information on a CD-RW disc ifyou have a CD-RW drive, of course.

DVD DRIVE


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Next generation DVD drives are quickly replacing CD-ROM drives in newer computers.A DVD (stands for DigitalVersatile Disc) disc looks just like a CD-ROM, but it can storemore than 4 Gigabytes (GB) of information as much asseven CDs. There are evenrumored to be future DVD discs that can hold up to 17 Gigabytes! Unfortunately therestillreally isnt a lot of software that is available on DVD discs. Most people simply usetheir DVD drive to watch DVDmovies. The CD-ROM drive is usually labeled D or E onmost computers.

New re-writable DVD drives, that can record or burn information to special type of DVDdiscs have recently becomeavailable the market.

Unfortunately for the consumer, thegreedy DVD manufacturers couldnt agree on a universal recordable DVDstandard, sothere are several different competing formats out there. Hopefully consumers willeventually make thedecision for the DVD manufacturers, like they did between Betamaxand VHS videotapes. Until then there isnt reallyany clear answer which recordable andrewritable DVD format to go with, although DVD+RW and DVD-RW discswork inmost new DVD drives and players.

DVD Format Description

DVD-ROM The original, standard DVD, ROM stands for Read-Only Memory. What this means is that you can onlyread information from a DVD ; you cant add new

information in a way.

DVD-R If you have a DVD-RW drive you can permanentlystore information on a DVD-R (DVD-Recordable) disc.The information you write or burn to a DVD-R ispermanent and cant be changed or erased.

DVD-RW drives can also write to DVD-RW discs

DVD-RW If you have a DVD-RW drive you can use DVD-RW(Rewritable) discs, which can be re-written to up to1,000 times. You can also modify and erase


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Information on a DVD-RW disc. DVD-RW discs havesome compatibility problems with older DVD Playersand DVD ROM drives.

DVD-RW drives can also write to DVD-R discs.

DVD+R If you have a DVD+RW drive you can permanentlystore information on a DVD+R (DVD+Recordable) disc.The information you write or burn to a DVD+R isper manent and cant be changed or erased.

DVD+RW drives can also write to DVD+RW discs.

DVD+RW If you have a DVD+RW drive you can use DVD+RW(Rewritable) discs, which can be rewritten to up to 1,000times. You can also modify and erase information on aDVD+RW disc. DVD+RW discs have somecompatibilityProblems with older DVD Players and DVD ROMdrives.

DVD+RW drives can also write to DVD+R discs.

DVD-RAM DVD-RAM is a rewritable DVD format that can be re-written to many times. DVD-RAM discs are beginningto look like an orphan format, since they wont work inmost DVD players.

FLOPPY DRIVE

Most desktop computers still have a floppy drive, although most laptops have dropped the all-but-obsolete floppydrive. Floppy drives read flat, 3-inch floppy disks. Floppy drives are as slow as molasses when compared to harddrives and CD-ROM drives.

Slower. Slow as a glacier. Floppy disks can only store a scant 1.44 Megabytes (MB) just a little more than yourtypical novel.


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So why these relics from the 1980 ares still around? Floppy disks can still be useful for transferring and backing upsmall documents.

ZIP AND JAZ DRIVES

Removable storage drives have features of both hard drives and floppy drives. Removable storage drives work like afloppy drive because they read and write information on small, removable cassettes that are about the size of a floppydisk.

They are like hard drives because each cassette can usually hold more than 100 Megabytes (MB) and is much fasterthan a floppy disk, but still not quite as fast as a hard drive. Two of the most popular removable storage drives arethe Zip drive and Jaz drive, both made by Iomega.

Zip disks can store 100 to 250 Megabytes (MB) on a removable disk about 70 to 170 times as much as an old floppydisk. Zip drives are available in both 100MB and 250MB versions. Youll need a 250MB version to read both 100MBand 250MB Zip disks. Zip disks are a great way to transfer and backup information but theyre not much of valuewhen compared to newer CD-RW and even newer DVD-RW discs.

Jaz disks can store 1 to 2 Gigabytes (GB) on a single removable disk as much as an older hard drive! Jaz drives arealso fast, though not as fast as a hard disk, so theyre great for backing up information. Despite their huge s toragecapacities, Jaz drives really never caught on.

OTHER STORAGE DEVICES

Device Description

A tape drive creates copies, or backups, of the files on acomputers hard drive onto a tape cartridge. The backedup files can be restored in case the original files are lost


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Tape Drive

due to a disaster or stupidity.

LS-120 SuperDrive

The LS-120 drive was meant to be an alternative to Zipdisks, because it could store 120 MB of data on a disk,and a replacement for floppy drives, because it couldalso read and write to traditional 1.44 MB floppy disks.Unfortunately LS-120 never really caught on with thegeneral public.

Flash Card

Flash cards are commonly used as the film for digitalcameras. Flash cards can store anywhere from a dozento several hundred pictures, depending on how muchmemory they have. There are three different types offlash cards:

Compact Flash cards, Smart Media cards, and MemorySticks. Flash cards can store anywhere from 4 MB all theway up to 1 GB. Wow!

USB Flash Drive

A USB flash drive is really another type of Flash Cardthat plugs into a USB port. USB flash drives range insizes from 16 MB to 512 MB.

FORMATTING A DISK


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Floppy disk must before format before you can use them. Fortunately today most floppy disks you can buy comppre- formatted, so you dont have to do it yourself. When you format a disk, you erase everything on it and prepare itso that it can be read and used by the computers operating system. Actually, you can format mos t storage devices,such as a hard disks and Zip disks, only youll want to be extra careful about formatting these devices, as theres a lotmore information that will be erased when you format them. Its easy to format a floppy disk. Heres the procedurefor formatting a floppy disk in Windows XP

Step 1 - Click the Start button and select My Computer . The My Computer window will display your computersvarious storage devices.

Step 2 - Right-click the drive containing the floppy disk you want to format (usually A:), and select Format fromthe shortcut menu.

Step 3 - Click Start .The floppy drive will whir as it formats the floppy disk. Formatting a floppy disk usually takes about a minute,formatting a hard disk takes a long time over an hour if you have a slow computer and large hard disk.

Quick (erase)Erases all information from the disk, but doesn't scan theDisk for damaged areas. Only works on disks that havePreviously been formatted.

Enable CompressionFormats the volume so that folders and files on it areCompressed. Compression is supported only on NTFSDrives.

Create an MS-DOS startup diskIf youre having problems with your computer, usea startup disk to help remedy your


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LESSON SUMMARY

CENTRAL PROCESSING UNIT (CPU)

The CPU, or Central Processing Unit, is the computers main chip. It calculates and processes information. CPU speed is measured in megahertz (MHz) and gigahertz (GHz). Common CPUs include: Intel Pentium III, Intel Pentium 4, Intel Celeron, AMD Athlon, AMD Duron

MEMORY

Computers function based on the binary system, where on is represented by a one (1) and Off is represented by a zero(0).

A Bit is the smallest memory unit. Bit stands for binary digit . Eight bits make one Byte . A byte equals one character (letter, number, or symbol). 1,024 bytes make one Kilobyte (K or KB) which is equivalent to a one-page, double-spaced letter.

1,048,576 bytes make one Megabyte (M or MB) which is equivalent to a novel. 1,073,741,824 bytes make one Gigabyte (G or GB) which is equivalent to an encyclopedia set. 1,099, 511,627,776 bytes make one Terabyte (T or TB) which is equivalent to a small bookstore.

RAM AND ROM

RAM: Stands for R andom Access Memory. This is computers main memory, which is used to processinformation. You can read from and write to RAM. RAM is volatile, and any data disappears when you shutoff computer.

ROM: Stands for Read Only Memory. This is the computers lo w-level memory, which is used to perform itsmost basic functions. You can read from, but not write to ROM.

MOUSE

A mouse acts as a handheld pointing device and controls the actions of that blinking item onyour computerscreen known as a cursor.

KEYBOARD

A keyboard lets you enter information and commands into a computer.

DIGITAL CAMERAS AND WEB CAMS

A digital camera lets you take pictures and transfer them to a computer. The quality or resolutions of the pictures a digital camera can take are measured in megapixels , or millions of

pixels (dots).

OTHER INPUT DEVICES

Other input devices include touch pads, AccuPoint pointing devices, track balls, light pens. scanners, joysticks, and microphones.

MONITORS


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A CRT Monitor is an older type of monitor that looks like a television screen. A Flat Panel LCD Monitor is a newer type of monitor that is thin, lightweight and some what expensive. The size of a monitor is measured diagonally across the screen. Average monitor sizes range from 15-inches

to 21-inches. The monitor refresh rate determines how quickly the monitor redraws, or updates, the image on the screen.

Most monitors have a refresh rate of 72MHz or better. A screen saver is a moving picture that appears on your computer screen when you dont use yo ur computer

for a while.

GRAPHICS CARDS

Screen Resolution determines how much information can fit on the computer screen at once. Commonscreen resolutions include 800 by 600 and 124 by 768.

Color Depth is the number of colors that are displayed on the screen at once. Common color depths include

16-bit and 24-bit color. Video Cards have their own memory and processor. Generally speaking, the more memory a video card has

the higher the resolution and color depth it can display.

PRINTER BASICS

Inkjet and Laser printers are the most common printer types. Printer resolution determines the quality of the images a printer can produce. Printer resolution is measured

in dots per inch (dpi). A printers speed determines how quickly it can print pages.

Printers get their ink from expensive cartridges (Inkjet printers) and toners (laser printers). Many printers have their own memory, which is required for printing more complex images. A print spooler or buffer temporary stores large print jobs and releases them when the printer is able to

actually print them.

SOUND AND SPEAKERS

A sound card lets a computer play and record digital sounds. Modems A standard modem transmits information over standard phone lines to other computers and has a maximum

speed of 56K bps. A broadband or digital modem is much faster than a standard modem, with speeds up to 6,000K bps.

Broadband modems include ISDN, DSL, and Cable.

INPUT/OUTPUT DEVICES

Some computer devices have both input and output functions. Examples include touch screen Monitors andmultifunction printers.

HARD DRIVE

A hard drive is a computers main storage device, usually labeled C. Modern hard drives can store anywhere from 20GB to 250GB of information.

Average access time is how fast a hard drive can find information.


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Hard drives are connected to a computer through either an IDE or SCSI interface.

HARD DRIVE MAINTENANCE

Hard Drive Repair and Fragmentation: Over time, small errors and fragmentation can degrade theperformance of a hard drive. These problems can be corrected by a hard drive utility program.

Hard Drive Backups: Should be preformed to give you an extra copy of your files if your hard drive becomesdamaged.

Virus Protection: Software should be installed on every computer to protect against malicious computerviruses.

Compression: Increases the space on a hard drive by compressing, or squeezing together, its files.

CD-ROM DRIVE

CD-ROM: Stands for Compact Disc-Read Only Memory. A CD-ROM drive lets you install Programs, run

CD-ROM based programs, and play audio CDs. A CD-ROM holds about 650MB of information. CD-R: Stands for Compact Disc-Recordable. Lets you permanently write or burn information. CD-RW: Stands for Compact Disc-Rewritable. Can be written to and modified many times.

DVD DRIVE

DVD: Stands for Digital Versatile Disc. A DVD disc looks like a CD-ROM, but can store much moreinformation.

Recordable and Rewritable DVDs: There are several competing, non-compatible formats out there,including DVD-R /DVD-RW and DVD+R/ DVD+RW.

FLOPPY DRIVE

Floppy disks are slow and can only store 1.44MB. They are all but obsolete. Zip and Jaz Drives Zip and Jaz drives are removable storage devices that have features of both floppy and hard disks.

OTHER STORAGE DEVICES

Other storage devices include tape drives, LS-120 Super drives, flash cards, and USB flashdrives.

FORMATTING A DISK

Formatting a disk prepares it for use, so that it can be read and use by the computersoperating system.Formatting a disk erases everything on it.

QUIZ

The speed of a CPU is measured in what?

A. Megahertz (MHz) and gigahertz (GHz)B. HorsepowerC. Bits per second (Bps)

D. Lux

How much information can be stored in a kilobyte?


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A. As much as a one page letter.B. As much as a novel.C. As much as an encyclopedia set.D. As much as a bookstore.

Generally speaking, which of the following storage devices can holdthe most information?

A. A hard diskB. A Zip diskC. A CD-ROMD. A DVD

What is another name for a computers main memory?

A. RAMB. ROMC. RUMD. Flash

You can read and write to a computers ROM. (True or False?)

Which of the following modems is the slowest?

A. ISDNB. DSLC. CableD. Standard

Which of the following modems is the slowest?

A. ISDNB. DSLC. CableD. Standard

Which of the following can you read and write to many times?

A. CD-ROMB. CD-RC. CD-RWD. DVD-ROM

QUIZ ANSWERS

The speed of the CPU, or Central Processing Unit, is measured in megahertz(MHz) and gigahertz (GHz).

A kilobyte holds 1,024 characters; about as much information as a singlepage letter.


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A hard disk will generally have more storage capacity than a Zip disk, CDROM,or even DVD.

RAM or Random Access Memory.

False. A computer can read from ROM but not write to it.

A standard modem is much slower than the other digital modems.

You can read and write to a CD-RW, or CD Rewritable disc many times.

UNDERSTANDING SOFTWARE

UNDERSTANDING GRAPHICAL USER INTERFACE

Abbreviated GUI (pronounced GOO-ee). A program interface that takes advantage ofthe computer's graphics capabilities to make the program easier to use. Well-designed graphical user interfaces canfree the user from learning complex command languages . On the other hand, many users find that they work moreeffectively with a command-driven interface, especially if they already know the command language.

Graphical user interfaces, such as Microsoft Windows and the one used by the Apple Macintosh , feature the

Taskbar

Start Menu

Recycle Bin

Desktop
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