L>Introduction to ComputersIntroduction to Computers

The huge Picture

A computer system system has three main components: hardware, software, andpeople. The equipment connected with a computer system system is dubbed hardware. software application is a collection of instructions that tells the hardware what to do.People, however, room the most vital component the a computer system system - civilization use the power of the computer for some purpose. In fact, this food will display you that the computer can be a device for simply aboutanyone from a organization person, come an artist, to a housekeeper, to a student -an incredibly powerful and functional tool. Software is in reality a computer system program. To be more specific, a programis a collection of step-by-step instructions the directs the computer system to do thetasks you want it to do and also to produce the outcomes you want. A computer system programmer is a person who write programs. Most of us carry out not compose programs, we use programs created by someone else. This method we areusers - human being who purchase and also use computer system software.

Hardware: meeting the Machine

What is a computer? A six-year-old called a computer system "radio, movies, andtelevision combined!" A ten-year-old described a computer as "a televisionset you deserve to talk to." The ten-year-old"s meaning is closer however still does notrecognize the computer system as a machine that has actually the strength to make changes.A computer system is a an equipment that have the right to be programmed to accept data (input),process that into useful information (output), and store it far (in a an additional storage device) for safekeeping or later reuse. The processing ofinput to output is command by the software but performed by the hardware.To function, a computer system system requires 4 main aspects of data handling: input, processing, output, and storage. The hardwareresponsible for these four areas operates as follows: Input tools accept data in a kind that the computer can use; lock thensend the data to the processing unit. The processor, more formally known as the central processing unit(CPU), has actually the electronic circuitry the manipulates intake data right into theinformation world want. The central processing unit executescomputer indict that are specified in the program. Output devices show people the handle data-information in aform that they have the right to use. storage usually means secondary storage. Second storage is composed of devices, such together diskettes, which can store data and programsoutside the computer itself. These devices supplement the computer"s memory, which, together we will see, can hold data and also programs just temporarily.Now let us think about the devices related to these four elements of datahandling in terms of what you would uncover on a personal computer.

You are watching: Processing tasks occur on the ____.

Your personal Computer Hardware

Let united state look in ~ the hardware in terms of a personal computer. Suppose youwant to carry out word processing on a an individual computer, making use of the hardwareshown in figure 1. number 1: an individual Computer
Word processing software enables you to input datasuch as an essay, conserve it, revise and re-save it, and print that whenever youwish. The intake device, in this case, is a keyboard, which you use to typein the initial essay and also any alters you desire to do to it. Allcomputers, large and small, must have a main processing unit in ~ the an individual computer housing. The main processing unit under the direction of theword handling software accepts the data you inputthrough the keyboard. Handle data from your personal computer isusually calculation in 2 forms: ~ above a screen and eventually through a printer. Together you key in theessay ~ above the keyboard, it shows up on the display in former of you. After ~ youexamine the essay ~ above the screen, make changes, and determine the it isacceptable, you deserve to print the essay on the printer. Your an additional storagedevice in this instance is a diskette, a magnetic medium that stores the essayuntil that is needed again.Now we will take a general tour that the hardware required for input, processing, output, and also storage. These exact same components make up all computer system systems, even if it is small, medium, or large. In this conversation we willtry to emphasize the varieties of hardware you are most likely to have actually seen in yourown environment. This topiptcouncil.net will certainly be covered in information in later on chapters.

Input: What walk In

Input is the data the you put right into the computer system system because that processing.Here space some typical ways the feeding input data right into the system: typing on a keyboard. Computer keyboards run inmuch the same means as electrical typewriter keyboards. The computerresponds to what girlfriend enter; that is, that "echoes" what you form by displaying the on the display in front of you. Pointing v a mouse. A mouse is a an equipment that is movedby hand over a flat surface. Together the sphere on its underside rotates, themouse movement causes corresponding movement of a guideline on thecomputer screen. Pressing buttons on the mouse allows you invoke commands. Scanning v a flatbed scanner, wand leader or bar password reader (Figure 3). number 3: Flatbed Scanner
Flatbed scanners act prefer a copying maker by utilizing light beams to scan adocument or picture that is laid upon its glass face. A great way to sendpictures with email!Bar scanners, i beg your pardon you have seen in sleeve stores, use laser beams come readspecial letters, numbers, or signs such as the zebra-striped bar codeson countless products.You can input data come a computer in plenty of other amazing ways,including writing, speaking, pointing, or also by just looking in ~ the data.We will examine all this in information in a later chapter.

The Processor and Memory: Data Manipulation

In a computer system the processor is the facility of activity. The processor, as wenoted, is also called the main processing unit (CPU). The main processing unit consists of electronic circuits that interpret and execute programinstructions, as well as communicate v the input, output, and storagedevices.It is the main processing unit that actually transforms data right into information. Data is the raw product to be handle by a computer. Suchmaterial deserve to be letters, numbers, or facts like qualities in a class, baseball batting averages, or light and dark locations in a photograph. Processeddata i do not care information, data that is organized, meaningful, and also useful. In school, for instance, an instructor could enter miscellaneous studentgrades (data), which deserve to be handle to develop final grades and perhapsa course average (information). Data that is probably uninteresting on itsown might become really interesting when it is convert to information. Theraw facts (data) about your finances, such together a paycheck or a donation tocharity or a medical bill may not be captivating individually, but together,these and also other acts deserve to be processed to produce the refund or lot youowe ~ above your earnings tax return (information).Computer memory, additionally known as main storage, is carefully associatedwith the main processing unit yet separate native it. Memory holds thedata after that is input to the system and also before it is processed; also, memoryholds the data after ~ it has actually been processed but prior to it has been released tothe calculation device. In addition, storage holds the program (computerinstructions) required by the central processing unit.

Output: What come Out

Figure 3: MonitorFigure 4: Printer
Output, the an outcome produced by the central processing unit, isa computer"s totality reason because that being. Calculation is usable information; thatis, raw input data that has actually been handle by the computer system into information. The mostcommon develops of output are words, numbers, and also graphiptcouncil.net. Native output, because that example, might be the letters and memos ready byoffice people using word handling software. Other workers may be moreinterested in numbers, such together those uncovered in formulas, schedules, andbudgets. In many situations numbers deserve to be understood more easily as soon as output in the form of charts and graphiptcouncil.net.The most typical output gadgets are computer screens (Figure 3)and printers (Figure 4).Screens deserve to vary in their creates of display, developing text, numbers, symbols, art, photographs, and even video-in complete color. Printers develop printed reports as instructed through a computer program, often in complete color. Girlfriend can create output indigenous a computer system in other ways, consisting of filmand voice output. We will study all output approaches in detail in a later chapter.

Secondary Storage

second storage provides additional storage separate from memory. Secondary storage has actually several advantages. Because that instance, it would certainly be unwisefor a college registrar to try to save the qualities of every the students in the college in the computer"s memory; if this to be done, the computer wouldprobably not have room to save anything else. Also, memory holds dataand programs only temporarily. Secondary storage is needed for big volumesof data and additionally for data that should persist after ~ the computer system is rotate off.
Figure 5: difficult DiskFigure 6: tough Disk Pack
The two most common second storage mediums room magnetic diskand magnetic tape. A magnetic disk have the right to be a diskette or a hard disk. Adiskette is typically 3-1/2 inches in diameter(in part rare instances older disks space 5-1/4 inches). A diskette is removable soyou can take her data v you. Tough disks, shown in figure 5, have morestorage capacity than diskettes and likewise offer faster access to the data theyhold. Difficult disks room often contained in diskpacks displayed in figure 6 the is developed into the computer system so her data stayswith the computer.Disk data is review by disk drives. An individual computer disk drives readdiskettes; most personal computers likewise have tough disk drives. Modernpersonal computer systems are starting to come through removable storage media, likeZip disks. These disks space slightly larger than a diskette and can it is in insertedand removed like a diskette, however hold much more data than a diskette and also arefaster because that the CPU to access than a diskette. Most modern-day computers also come witha CD-ROM drive. A CD is anoptical disk, it usesa laser beam to read the disk. CD"s are removable andstore large volumes that data fairly inexpensively. Part CD drives areread only memory (ROM), which way that your computer can check out programsfrom CD"s, yet you have the right to not conserve data come the CD yourself. Freshly CD-RW drives and also disks have end up being widely accessible that permit you to produce your own CDs by "writing" data such together music and also photos to the CD.Magnetic tape, which come on a reel or cartridge displayed in number 7,
Figure 7: Magnetic Tape
is comparable to tapethat is played on a tape recorder. Magnetic ice reels are an installed on tapedrives once the data on them needs to be check out by the computer system orwhen new data is come be composed on the tape. Magnetic ice isusually supplied for creating backup copies of huge volumes that data due to the fact that tape isvery inexpensive contrasted to disks and also CDs.We will examine storage media in a later part of the course.

The complete Hardware System

The hardware devices attached to the computer are dubbed peripheralequipment. Peripheral equipment contains all input, output, and secondarystorage devices. In the instance of personal computers, few of the input, output, and also storagedevices are developed into the very same physical unit. In many personal computers, the CPU and disk drive room all had in the samehousing; the keyboard, mouse, and screen room separate.In larger computer system systems, however, the input, processing, output, andstorage functions may it is in in different rooms, different buildings, or evenseparate countries. For example, data may be input on terminals at abranch bank and also then transmitted come the main processing unit in ~ theheadquarters bank. The information developed by the main processingunit may then it is in transmitted come the global offices, where it isprinted out. Meanwhile, disks v stored data may be maintained in financial institution headquarters and also duplicate data retained on disk or tape in a warehouse acrosstown for safekeeping.Although the tools may vary widely, from the simplest computerto the many powerful, by and huge the four facets of a computer system systemremain the same: input, processing, output, and also storage. Now let us lookat the way computers have been traditionally classified.

Classification of Computers

Computers come in sizes from tiny to monstrous, in both figure andpower. The dimension of a computer system that a person or an company needsdepends ~ above the computer requirements. Clearly, the nationwide WeatherService, maintaining watch on the weather fronts of numerous continents, hasrequirements different from those that a auto dealer"s organization department thatis trying to save track of its components inventory. And also the requirements of bothof castle are different from the requirements of a salesperson using a tiny laptopcomputer come record client orders ~ above a sales trip.SupercomputersThe mightiest computers-and, of course, the many expensive-are knownas supercomputers (Figure 1-6a). Supercomputers process billions ofinstructions per second. Most human being do not have a direct need for thespeed and also power the a supercomputer. In fact, for many years supercomputer customers were an exclusive group: organ of the commonwealth government. The federal government uses supercomputers for tasks that requiremammoth data manipulation, together as an international weather forecasting andweapons research. However now supercomputers are relocating toward the mainstream, because that activitiesas differed as share analysis, automobile design, specialeffects for movies, and even innovative artworks (Figure 1-7).Mainframes
Figure 8: Mainframe Computer
Figure 9: Mainframe Computer
In the jargon of the computer system trade, huge computers are referred to as mainframes. Mainframes are qualified of processing data at very high speeds-millions of instructions per second-and have accessibility to billions of personalities of data. The price the these big systems deserve to vary from severalhundred thousands to countless millions that dollars. V that type of price tag,you will certainly not purchase a mainframe for just any type of purpose. Their major use isfor processing large amounts the data quickly, so some of the apparent customers are banks, insurance companies, and also manufacturers. Yet this perform isnot all-inclusive; other varieties of customers are big mail-order houses, airline with innovative reservation systems, government bookkeeping services, aerospace suppliers doing complicated aircraft design, and the like. In the 1960s and1970s mainframes dominated the computer system landscape. The 80s and early 90s had manypeople predicting that, through the development of very powerful and affordable an individual computers, that mainframes would end up being extinct favor the huge dinosaursin nature"s progression. However, through the tremendous explosion ofthe web in the mid 90s, mainframes may have been reborn. The currentWorld large Web is based upon the client/server paradigm, wherein serverson the Internet, prefer LL Bean"s internet Server, carry out services, choose onlineshopping, to millions of civilization using personal computers together clients. The capacityrequired of these servers may be what saves the mainframe! personal ComputersPersonal computers are often referred to as Pptcouncil.net. They range in pricefrom a few hundred dollars to a few thousand dollars when providingmore computing power 보다 mainframes of the 1970s that filled entirerooms. A pc usually comes through a tower the holds the maincircuit boards and also disk cd driver of the computer, and a collection of peripherals,such together a keyboard, mouse, and monitor.In the brand-new millennium there room two key kinds of Pptcouncil.net: the apologize Macintosh line,and "all that the others". The ax "PC" or "IBM" describes "all that the others", i beg your pardon is a historical artifact ago to the days as soon as IBM and also Apple to be thetwo main competitors in the market and also IBM dubbed its machine a "personalcomputer". So, although a Macintosh is a personal computer, the term "PC"often method a an equipment other than a Macintosh.Macintoshes and Pptcouncil.net, in general, have the right to not run software program that was created theother, without part specialtechnology added to them. They run on various microprocessors. A PCis based on a microprocessor initially made through the Intel firm (such as Intel"s Pentium, although various other companies such together AMD currently make"Pentium clones" that have the right to run pc software.).Macintoshes use a PowerPC processor, or on larger Macintoshes a processor do byMotorola.Also, the operating mechanism software the runs the two kinds of computers is different. Pptcouncil.net usuallyuse an Operating system made by Microsoft, favor Windows98 or Windows2000. Macintoshes use adifferent operation system, called MacOS, do by Apple. There room effortsto do the two kinds of computers compatible. As Apple continues to loseits re-publishing of the market, Apple has actually the impetus to either sign up with the remainder ordisappear.
Figure 10: Notebook Computer
Notebook ComputersA computer system that fits in a briefcase? A computer that weighs much less than anewborn baby? A computer system you execute not have to plug in? A computer system to useon her lap on an airplane? Yes, to every these questions. Notebook computers,also known as Laptop computers, are wonderfully portable and also functional,and renowned with travelers who require a computer that deserve to go with them. Most notebooksaccept diskettes or network connections,so the is basic to relocate data fromone computer system to another. Notebooks are not as cheap as your sizemight suggest; many carry a price tag equivalent to a full-size personalcomputer because that business. They typically have nearly as much computer capacityin terms of speed and storage. They carry out not offer the full expandabilityfor supporting peripherals together a personal computer. For instance a MIDI computermusic key-board may not be adaptable come a notebook computer. However, much more andmore peripherals are offering connectivity to laptop computers through a technologycalled PCMCIA which enables peripherals to be plugged right into notebook computer systems throughcredit card sized cards that quickly slip right into the side of a notebook computer.Normal size Pptcouncil.net space still much more powerful, flexible, and also cheaper, but notebooksare becoming more competitive every day.
Figure 11: Handheld Computer
Getting smaller StillUsing a pen-like stylus, pen-based computer systems accept handwritten inputdirectly top top a screen. Customers of the handheld pen-based computers,also called an individual digital aides (PDA), like the Palm, enjoy having actually applications such together calendars, resolve books, and games readily available. Recent PDA"s offer net access, email, andcellular telephoning.

Internet and also Networking

The internet is the most widely recognized and used type of computernetwork . Networks connect computers come each other to permit communication andsharing that services.Originally, a computer system user kept all the computer hardware in one place;that is, that was centralized in one room. Anyone wanting computer system accesshad to go to wherein the computer was located. Back this is still occasionally the case, most computer system systems space decentralized. The is, the computer itself and some storage gadgets may it is in in one place, but the devicesto accessibility the computer-terminals or even other computers-are scatteredamong the users. These gadgets are usually associated to the computer bytelephone lines. Because that instance, the computer and also storage that has the information on your checking account may be located in financial institution headquarters.but the terminals are located in branch financial institutions all over city so a teller inany branch can find out what her balance is. The subject of decentralization is intimately tied to data communications, the process of exchangingdata over communications facilities, such together the telephone.A network uses interactions equipment to connectcomputers and also their resources. In one type of network, a local areanetwork (LAN), personal computers in one office room hooked together sothat users can connect with each other. Users have the right to operate theirpersonal computers independently or in collaboration with otherPptcouncil.net or mainframes to exchange data and share resources. We discuss computernetworks in information in a later chapter.

Software: telling the machine What to Do

In the past, when people thought about computers, they thought aboutmachines. The tapping ~ above the keyboard, the clacking the the printers, therumble of whirling decaying drives, the transforming flashes of color on a computerscreen-these room the attention-getters. However, that is yes, really the software-the planned, step-by-step instructions compelled to rotate data into information-that makes a computer useful.Categories the Software.Generally speaking, software deserve to be categorized as device software orapplications software. A subset of mechanism software is an operation system,the underlying software found on all computers. Applications software,software the is applied, can be provided to fix a particular problem or toperform a particular task. Applications software may be either tradition orpackaged. Many huge organizations salary programmers to compose customsoftware, software that is particularly tailored to their needs. Wewill use several creates of mechanism software (e.g. Windows 2000, MacOS) andseveral application software program programs (e.g. Word, Excel, PowerPoint) inthis course.Some Task-Oriented Software.Most users, even if it is at house or in business, are drawn to task-orientedsoftware, sometimes called productivity software, that have the right to make their occupational faster and their lives easier. The collective collection of organization tasks is limited, and also the number of general courses towards performing these work islimited, too. Thus, the tasks and the software program solutions fall, because that the mostpart, into just a couple of categories, which have the right to be found in most organization environments. These major categories space word handling (including desktoppublishing), spreadsheets, database management, graphiptcouncil.net, and communications. We will existing a brief description of each group here.Word Processing/Desktop PublishingThe most widely used an individual computer software application is word handling software. This software lets you create, edit, format, store, and also print message andgraphiptcouncil.net in one document. In this meaning it is the three words in themiddle-edit, format, and also store-that reveal the difference between wordprocessing and also plain typing. Because you can store the memo or documentyou kind on disk, you have the right to retrieve it an additional time, adjust it, reprint it, ordo every little thing you prefer with it. You can see what a good time-saver wordprocessing can be: unchanged components of the stored paper do not need tobe retyped; the entirety revised paper can that reprinted as if new. Together the variety of features in word processing packages has grown,word processing has crossed the border into desktop computer publishing territory.Desktop publishing packages room usually far better than indigenous processingpackages at conference high-level publishing needs, especially when that comesto typesetting and color reproduction. Many magazines and newspaperstoday rely on desktop computer publishing software. Businesses use it to produceprofessional-looking newsletters, reports, and brochures-both toimprove interior communication and also to make a much better impression ~ above theoutside world.Electronic SpreadsheetsSpreadsheets, consisted of of columns and rows, have been provided as businesstools for centuries (Figure 11). A manual spreadsheet have the right to be tedious toprepare and, when there space changes, a considerable amount that calculation may need to he redone. An electronic spreadsheet is quiet a spreadsheet, but the computer system does the work. In particular, spreadsheet softwareautomatically recalculates the results once a number is changed. Thiscapability lets business people shot different combinations of numbers andobtain the results quickly. This capacity to questioning "What if . . . ?" helps service people make better, much faster decisions.In this course, we usage Microsoft"s Excel spreadsheet applications software.
Figure 11: Spreadsheet Software
Database ManagementSoftware used for database management-the management of a collectionof interrelated facts-handles data in numerous ways. The software can storedata, upgrade it, manipulate it, report the in a range of views, and print the inas plenty of forms. By the moment the data is in the reporting stage-given come auser in a useful form-it has come to be information. A concert promoter, forexample, deserve to store and adjust data around upcoming concert dates, seating, ticket prices, and also sales. ~ this is done, the promoter have the right to use thesoftware come retrieve information, such together the variety of tickets offered in eachprice range or the portion of tickets marketed the day prior to the concert.Database software have the right to be advantageous for everyone who must keep track of alarge variety of facts. Database software is presented in number 12.

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Figure 12: Database Software
Graphiptcouncil.netIt could seem rubbish to display graphiptcouncil.net to service people once standardcomputer printouts are readily available. However, graphiptcouncil.net, maps, andcharts can help people compare data and also spot trends much more easily, andmake decisions an ext quickly. In addition, intuitive informationis usually much more compelling 보다 a page of numbers. We usage Microsoft"s PowerPoint and also Adobe"s Photoshop application software application for graphiptcouncil.net. We use it in two ways:for doing original drawings, and also for developing visual aids to job as asupport to an oral presentation.CommunicationsWe have already described communications in a basic way. From theviewpoint of a worker with a personal computer at home, interactions means-in basic terms-that the or she can hook a phone up to thecomputer and communicate v the computer at the office, or acquire at datastored in someone else"s computer system in one more location. We use Microsoft"sInternet traveler application software program for act email, World wide Web browsing,and participating in Internet discussion groups.