what does a computer do with the input in storage to create output

---

Introduction to Computers

---

The Big Picture

A computer organisation has three main components: hardware, software, and people. The equipment associated with a computer system is called hardware. Software is a set of instructions that tells the hardware what to practise. People, nonetheless, are the most important component of a computer system - people use the power of the computer for some purpose. In fact, this grade will show you that the computer can be a tool for just virtually anyone from a business person, to an artist, to a housekeeper, to a educatee - an incredibly powerful and flexible tool.

Software is actually a estimator programme. To exist more than specific, a program is a set of step-by-step instructions that directs the computer to practise the tasks y'all desire it to do and to produce the results you lot want. A computer programmer is a person who writes programs. Nearly of us do not write programs, we use programs written by someone else. This means we are users - people who purchase and use calculator software.

Hardware: Meeting the Machine

What is a computer? A six-twelvemonth-former called a computer "radio, movies, and television combined!" A x-yr-one-time described a reckoner as "a telly you can talk to." The ten-yr-old's definition is closer merely still does not recognize the computer as a machine that has the power to make changes.

A figurer is a car that can be programmed to accept data (input), process it into useful data (output), and store information technology away (in a secondary storage device) for safekeeping or after reuse. The processing of input to output is directed by the software just performed by the hardware.

To function, a computer organisation requires four main aspects of data handling: input, processing, output, and storage. The hardware responsible for these 4 areas operates as follows:

• Input devices accept information in a form that the computer can utilise; they then send the data to the processing unit.
• The processor, more formally known as the key processing unit (CPU), has the electronic circuitry that manipulates input data into the information people want. The primal processing unit executes computer instructions that are specified in the program.
• Output devices prove people the processed information-information in a class that they can apply.
• Storage normally means secondary storage. Secondary storage consists of devices, such as diskettes, which can store data and programs outside the reckoner itself. These devices supplement the estimator's memory, which, every bit nosotros will see, can hold data and programs only temporarily.

Now let us consider the equipment related to these 4 aspects of data handling in terms of what you lot would find on a personal computer.

Your Personal Estimator Hardware

Let us await at the hardware in terms of a personal calculator. Suppose you want to do word processing on a personal computer, using the hardware shown in Figure one.

Figure 1: Personal Computer

Give-and-take processing software allows y'all to input data such equally an essay, save it, revise and re-salve it, and print it whenever you wish. The input device, in this case, is a keyboard, which you use to blazon in the original essay and any changes you want to make to it. All computers, big and small, must have a key processing unit of measurement within the personal estimator housing. The key processing unit under the direction of the word processing software accepts the data you input through the keyboard. Processed information from your personal reckoner is commonly output in two forms: on a screen and eventually by a printer. As y'all central in the essay on the keyboard, information technology appears on the screen in forepart of yous. After you lot examine the essay on the screen, brand changes, and determine that it is acceptable, yous can print the essay on the printer. Your secondary storage device in this case is a diskette, a magnetic medium that stores the essay until it is needed again.

Now we will take a full general tour of the hardware needed for input, processing, output, and storage. These aforementioned components make up all calculator systems, whether pocket-sized, medium, or large. In this discussion we will attempt to emphasize the types of hardware you are likely to have seen in your own environment. These topics will be covered in detail in later chapters.

Input: What Goes In

Input is the information that you put into the computer system for processing. Hither are some common ways of feeding input data into the system:

• Typing on a keyboard. Computer keyboards operate in much the same way every bit electric typewriter keyboards. The computer responds to what yous enter; that is, it "echoes" what you blazon past displaying information technology on the screen in front of you.
• Pointing with a mouse. A mouse is a device that is moved past hand over a flat surface. As the ball on its underside rotates, the mouse movement causes corresponding move of a pointer on the reckoner screen. Pressing buttons on the mouse lets you invoke commands.
• Scanning with a flatbed scanner, wand reader or bar code reader (Figure 3).

  Figure 3: Flatbed Scanner

  Flatbed scanners deed like a copying machine by using light beams to scan a document or film that is laid upon its glass face. A great way to send pictures through electronic mail! Bar scanners, which you lot have seen in retail stores, apply laser beams to read special messages, numbers, or symbols such as the zebra-striped bar codes on many products.

Y'all tin can input information to a computer in many other interesting means, including writing, speaking, pointing, or fifty-fifty past just looking at the data. We volition examine all these in detail in a later affiliate.

The Processor and Retention: Information Manipulation

In a figurer the processor is the center of activity. The processor, as we noted, is also chosen the cardinal processing unit (CPU). The cardinal processing unit consists of electronic circuits that interpret and execute program instructions, as well as communicate with the input, output, and storage devices.

It is the central processing unit that actually transforms data into information. Data is the raw material to be processed by a reckoner. Such material can be messages, numbers, or facts like grades in a form, baseball batting averages, or light and dark areas in a photograph. Processed information becomes information, data that is organized, meaningful, and useful. In school, for instance, an instructor could enter various student grades (data), which tin exist processed to produce last grades and possibly a class average (data). Data that is perchance uninteresting on its own may become very interesting once it is converted to information. The raw facts (information) about your finances, such as a paycheck or a donation to charity or a medical bill may not exist captivating individually, just together, these and other acts can be processed to produce the refund or amount you lot owe on your income tax return (information).

Calculator retentivity, also known every bit master storage, is closely associated with the cardinal processing unit but separate from information technology. Memory holds the information after it is input to the system and before it is processed; besides, memory holds the data afterward it has been processed but before it has been released to the output device. In addition, retentivity holds the programs (computer instructions) needed by the central processing unit.

Output: What Comes Out

Output, the consequence produced past the central processing unit, is a computer's whole reason for being. Output is usable information; that is, raw input information that has been processed past the calculator into information. The near common forms of output are words, numbers, and graphics. Word output, for example, may be the letters and memos prepared by part people using discussion processing software. Other workers may be more interested in numbers, such every bit those found in formulas, schedules, and budgets. In many cases numbers can exist understood more easily when output in the course of charts and graphics.

The most mutual output devices are figurer screens (Figure three)and printers (Figure 4). Screens tin vary in their forms of display, producing text, numbers, symbols, fine art, photographs, and even video-in full color. Printers produce printed reports as instructed by a computer program, frequently in total color.

Yous can produce output from a computer in other means, including pic and voice output. Nosotros volition examine all output methods in item in a later affiliate.

Secondary Storage

Secondary storage provides additional storage separate from memory. Secondary storage has several advantages. For instance, it would be unwise for a higher registrar to try to keep the grades of all the students in the college in the computer's retentiveness; if this were washed, the computer would probably not have room to store annihilation else. Besides, memory holds data and programs just temporarily. Secondary storage is needed for large volumes of data and also for information that must persist subsequently the computer is turned off.

The two nearly common secondary storage mediums are magnetic disk and magnetic tape. A magnetic disk can be a diskette or a hard disk. A diskette is ordinarily 3-1/two inches in diameter (in some rare cases older disks are 5-one/4 inches). A diskette is removable then you tin take your data with you. Hard disks, shown in Figure 5, have more storage capacity than diskettes and also offer faster access to the information they hold. Hard disks are oft independent in disk packs shown in Figure 6 that is built into the computer so your data stays with the computer. Deejay data is read by deejay drives. Personal computer disk drives read diskettes; nearly personal computers also have hard disk drives. Modern personal computers are starting to come with removable storage media, like Zip disks. These disks are slightly larger than a diskette and can be inserted and removed like a diskette, just hold much more data than a diskette and are faster for the CPU to access than a diskette. Near modernistic computers too come with a CD-ROM drive. A CD is an optical disk, it uses a laser beam to read the deejay. CD's are removable and store large volumes of data relatively inexpensively. Some CD drives are read only retentiveness (ROM), which means that your reckoner tin can read programs from CD's, just y'all can not save information to the CD yourself. Recently CD-RW drives and disks have become widely available that allow you lot to create your ain CDs by "writing" data such equally music and photos to the CD.

Magnetic tape, which comes on a reel or cartridge shown in Effigy seven,

Effigy 7: Magnetic Tape

is similar to record that is played on a record recorder. Magnetic record reels are mounted on tape drives when the information on them needs to be read by the computer organization or when new data is to exist written on the tape. Magnetic tape is usually used for creating fill-in copies of large volumes of data because tape is very inexpensive compared to disks and CDs.

Nosotros will study storage media in a later part of the class.

The Complete Hardware System

The hardware devices attached to the computer are called peripheral equipment. Peripheral equipment includes all input, output, and secondary storage devices. In the case of personal computers, some of the input, output, and storage devices are built into the same physical unit. In many personal computers, the CPU and disk drive are all contained in the same housing; the keyboard, mouse, and screen are separate.

In larger computer systems, however, the input, processing, output, and storage functions may exist in divide rooms, separate buildings, or even separate countries. For case, data may exist input on terminals at a branch bank then transmitted to the central processing unit at the headquarters bank. The information produced by the key processing unit may and then exist transmitted to the international offices, where it is printed out. Meanwhile, disks with stored data may exist kept in bank headquarters and duplicate data kept on disk or tape in a warehouse across boondocks for safekeeping.

Although the equipment may vary widely, from the simplest figurer to the virtually powerful, more often than not the four elements of a computer system remain the same: input, processing, output, and storage. Now let the states wait at the way computers have been traditionally classified.

Classification of Computers

Computers come in sizes from tiny to monstrous, in both advent and ability. The size of a calculator that a person or an organization needs depends on the computing requirements. Clearly, the National Weather Service, keeping watch on the weather fronts of many continents, has requirements different from those of a car dealer's service department that is trying to keep track of its parts inventory. And the requirements of both of them are unlike from the needs of a salesperson using a small laptop calculator to record client orders on a sales trip.

Supercomputers
The mightiest computers-and, of course, the most expensive-are known as supercomputers (Figure one-6a). Supercomputers process billions of instructions per second. Most people do not accept a direct need for the speed and power of a supercomputer. In fact, for many years supercomputer customers were an sectional group: agencies of the federal government. The federal government uses supercomputers for tasks that require mammoth information manipulation, such as worldwide weather forecasting and weapons research. But at present supercomputers are moving toward the mainstream, for activities equally varied as stock analysis, automobile pattern, special effects for movies, and even sophisticated artworks (Figure 1-vii).

Mainframes

In the jargon of the computer trade, big computers are called mainframes. Mainframes are capable of processing data at very high speeds-millions of instructions per second-and accept access to billions of characters of data. The cost of these large systems can vary from several hundred m to many millions of dollars. With that kind of cost tag, you volition non buy a mainframe for just whatever purpose. Their primary use is for processing vast amounts of data quickly, so some of the obvious customers are banks, insurance companies, and manufacturers. But this list is non all-inclusive; other types of customers are large post-order houses, airlines with sophisticated reservation systems, authorities accounting services, aerospace companies doing complex shipping design, and the like.

In the 1960s and 1970s mainframes dominated the computer mural. The 80s and early 90s had many people predicting that, with the advent of very powerful and affordable personal computers, that mainframes would go extinct similar the huge dinosaurs in nature'south progression. Yet, with the incredible explosion of the Cyberspace in the mid 90s, mainframes may have been reborn. The current World wide web is based on the client/server prototype, where servers on the Cyberspace, like LL Bean's Spider web Server, provide services, like online shopping, to millions of people using personal computers as clients. The chapters required of these servers may be what saves the mainframe!

Personal Computers
Personal computers are often called PCs. They range in price from a few hundred dollars to a few thousand dollars while providing more than computing power than mainframes of the 1970s that filled entire rooms. A PC unremarkably comes with a tower that holds the main excursion boards and deejay drives of the calculator, and a collection of peripherals, such as a keyboard, mouse, and monitor.

In the new millennium at that place are two main kinds of PCs: the Apple Macintosh line, and "all of the others". The term "PC" or "IBM" refers to "all of the others", which is a historical artifact back to the days when IBM and Apple were the 2 primary competitors in the market place and IBM chosen its auto a "personal computer". Then, although a Macintosh is a personal computer, the term "PC" ofttimes means a machine other than a Macintosh.

Macintoshes and PCs, in general, tin can not run software that was made for the other, without some special engineering added to them. They run on different microprocessors. A PC is based on a microprocessor originally made past the Intel company (such as Intel's Pentium, although other companies such every bit AMD at present make "Pentium clones" that can run PC software.). Macintoshes use a PowerPC processor, or on older Macintoshes a processor made by Motorola. Too, the operating system software that runs the two kinds of computers is different. PCs usually employ an Operating System made past Microsoft, like Windows98 or Windows2000. Macintoshes use a different operating system, chosen MacOS, fabricated past Apple tree. There are efforts to brand the two kinds of computers uniform. As Apple continues to lose its share of the marketplace, Apple has the incentive to either join the rest or disappear.

Figure 10: Notebook Calculator

Notebook Computers
A computer that fits in a briefcase? A computer that weighs less than a newborn infant? A computer you practice non take to plug in? A estimator to employ on your lap on an airplane? Yes, to all these questions. Notebook computers, as well known as Laptop computers, are wonderfully portable and functional, and popular with travelers who need a computer that can go with them. About notebooks accept diskettes or network connections, and then it is piece of cake to move data from 1 estimator to another. Notebooks are not as inexpensive as their size might propose; many carry a price tag equivalent to a full-size personal calculator for business. They typically take almost equally much computer capacity in terms of speed and storage. They practice not offer the total expandability for supporting peripherals as a personal estimator. For instance a MIDI computer music keyboard may non be adaptable to a notebook computer. Notwithstanding, more and more than peripherals are providing connectivity to laptops through a engineering science called PCMCIA which allows peripherals to be plugged into notebook computers through credit card sized cards that easily skid into the side of a notebook reckoner. Normal sized PCs are still more powerful, flexible, and cheaper, but notebooks are becoming more competitive every day.

Figure eleven: Handheld Calculator

Getting Smaller Still
Using a pen-like stylus, pen-based computers accept handwritten input directly on a screen. Users of the handheld pen-based computers, also called personal digital assistants (PDA), similar the Palm, enjoy having applications such as calendars, address books, and games readily available. Recent PDA'south offer Net admission, e-mail, and cellular telephoning.

Net and Networking

The Internet is the most widely recognized and used form of computer network . Networks connect computers to each other to let communication and sharing of services. Originally, a figurer user kept all the estimator hardware in one place; that is, it was centralized in 1 room. Anyone wanting computer access had to go to where the reckoner was located. Although this is even so sometimes the instance, most computer systems are decentralized. That is, the computer itself and some storage devices may be in one place, only the devices to access the reckoner-terminals or even other computers-are scattered among the users. These devices are ordinarily connected to the computer past telephone lines. For case, the figurer and storage that has the information on your checking account may be located in banking company headquarters. only the terminals are located in co-operative banks all over town so a teller in any branch can detect out what your residuum is. The subject of decentralization is intimately tied to data communications, the process of exchanging information over communications facilities, such as the telephone.

A network uses communications equipment to connect computers and their resources. In one blazon of network, a local surface area network (LAN), personal computers in an office are hooked together and then that users can communicate with each other. Users tin can operate their personal computers independently or in cooperation with other PCs or mainframes to exchange data and share resources. We hash out computer networks in detail in a later chapter.

Software: Telling the Machine What to Do

In the past, when people thought about computers, they thought nigh machines. The tapping on the keyboard, the clacking of the printers, the rumble of whirling disk drives, the changing flashes of color on a computer screen-these are the attention-getters. Yet, information technology is really the software- the planned, step-by-pace instructions required to turn data into information-that makes a computer useful.

Categories of Software.
Generally speaking, software tin be categorized every bit system software or applications software. A subset of organisation software is an operating organisation, the underlying software found on all computers. Applications software, software that is practical, tin be used to solve a particular problem or to perform a detail job. Applications software may be either custom or packaged. Many large organizations pay programmers to write custom software, software that is specifically tailored to their needs. We will use several forms of system software (e.m. Windows 2000, MacOS) and several application software programs (due east.chiliad. Word, Excel, PowerPoint) in this course.

Some Job-Oriented Software.
Most users, whether at abode or in business, are drawn to task-oriented software, sometimes called productivity software, that tin can make their work faster and their lives easier. The collective set of business tasks is express, and the number of general paths towards performing these tasks is limited, too. Thus, the tasks and the software solutions fall, for the about part, into just a few categories, which can exist institute in virtually business environments. These major categories are word processing (including desktop publishing), spreadsheets, database direction, graphics, and communications. We will present a brief clarification of each category here.

Word Processing/Desktop Publishing
The most widely used personal figurer software is give-and-take processing software. This software lets you create, edit, format, store, and print text and graphics in i document. In this definition it is the three words in the middle-edit, format, and store-that reveal the difference betwixt discussion processing and manifestly typing. Since you can store the memo or certificate y'all type on deejay, yous can retrieve it another fourth dimension, change it, reprint it, or do whatever y'all like with information technology. You lot can run across what a groovy fourth dimension-saver word processing can be: unchanged parts of the stored document exercise not need to exist retyped; the whole revised document can he reprinted as if new.

Every bit the number of features in word processing packages has grown, word processing has crossed the border into desktop publishing territory. Desktop publishing packages are usually better than word processing packages at meeting high-level publishing needs, particularly when it comes to typesetting and color reproduction. Many magazines and newspapers today rely on desktop publishing software. Businesses use information technology to produce professional person-looking newsletters, reports, and brochures-both to amend internal communication and to make a better impression on the outside earth.

Electronic Spreadsheets
Spreadsheets, fabricated upwards of columns and rows, have been used as business tools for centuries (Figure eleven). A transmission spreadsheet can exist tiresome to gear up and, when at that place are changes, a considerable amount of calculation may need to he redone. An electronic spreadsheet is nonetheless a spreadsheet, but the estimator does the work. In particular, spreadsheet software automatically recalculates the results when a number is changed. This capability lets business organisation people attempt different combinations of numbers and obtain the results quickly. This power to ask "What if . . . ?" helps concern people make better, faster decisions. In this course, we utilise Microsoft's Excel spreadsheet awarding software.

Figure 11: Spreadsheet Software

Database Management
Software used for database management-the management of a collection of interrelated facts-handles information in several ways. The software tin store data, update information technology, manipulate information technology, report it in a variety of views, and print it in as many forms. By the time the information is in the reporting stage-given to a user in a useful form-it has become information. A concert promoter, for example, tin store and change information well-nigh upcoming concert dates, seating, ticket prices, and sales. After this is done, the promoter can apply the software to retrieve information, such as the number of tickets sold in each price range or the percentage of tickets sold the day before the concert. Database software can be useful for anyone who must keep track of a large number of facts. Database software is shown in Figure 12.

Figure 12: Database Software

Graphics
It might seem wasteful to testify graphics to business people when standard computer printouts are readily bachelor. However, graphics, maps, and charts tin help people compare data and spot trends more easily, and make decisions more quickly. In addition, visual data is normally more compelling than a folio of numbers. We use Microsoft'southward PowerPoint and Adobe's Photoshop application software for graphics. We use it in ii ways: for doing original drawings, and for creating visual aids to projection every bit a support to an oral presentation.

Communications
Nosotros have already described communications in a general manner. From the viewpoint of a worker with a personal computer at home, communications means-in simple terms-that he or she can hook a telephone upwards to the computer and communicate with the calculator at the office, or get at data stored in someone else's reckoner in another location.  We use Microsoft'south Internet Explorer application software for doing email, World Wide Web browsing, and participating in Internet discussion groups.

mcdougaldbegicke.blogspot.com

Source: https://homepage.cs.uri.edu/faculty/wolfe/book/Readings/Reading01.htm

Share this post