WHAT IS A COMPUTER The term computer is used to describe a device made up of a combination of electronic and electromechanical (part electronic and part mechanical) components. Computer has no intelligence by itself and is referred to as hardware. A computer system is a combination of five elements: • Hardware • Software • People • Procedures • Data/information When one computer system is set up to communicate with another computer system, connectivity becomes the sixth system element. In other words, the manner in which the various individual systems are connected — for example, by phone lines, microwave transmission, or satellite — is an element of the total computer system.
Software is the term used to describe the instructions that tell the hardware how to perform a task. Without software instructions, the hardware doesn’t know what to do. People, however, are the most important component of the computer system: they create the computer software instructions and respond to the procedures that those instructions present. The basic job of computer is processing information. Computers accept information in the form of instruction called a programme and characters called data to perform mathematical and logical operations, and then give the results. The data is raw material while information is organized, processed, refined and useful for decision making. Computer is used to convert data into information. HADWARE What is hardware? Webster/s dictionary gives us the following of the hardware – the mechanical, magnetic, electronic, and electrical devices composing a computer system. Computer hardware can be divided into four categories: 1) input hardware 2) processing hardware 3) storage hardware 4) output hardware. 5) Input hardware The purpose of the input hardware is to collect data -d convert it into a form suitable for computer -processing. The most common input device is a keyboard, looks very much like a typewriter. The mouse is a hand id device connected to the computer by small cable. As the mouse is rolled across the mouse pad, the cursor moves -across the screen. When the cursor reaches the desired location, the user usually pushes a button on the mouse once or twice to signal a menu selection or a command to the computer. The light pen uses a light sensitive photoelectric cell ; signal screen position to the computer. Another type : input hardware is optic-electronic scanner that is used -o input graphics as well as typeset characters. Microphone tad digital camera can be also used to input data into the computer. Processing hardware The purpose of processing hardware is retrieve, interpret and direct the execution of software instructions provided to the computer. The most common components of processing hardware are the Central Processing Unit ^nd main memory. The Central Processing Unit (CPU) is the brain of the computer. It reads and interprets software instructions and coordinates the processing activities that must take place. The design of the CPU affects the processing pow¬er and the speed of the computer, as well as the amount of main memory it can use effectively. With a well-de¬signed CPU in your computer, you can perform highly sophisticated tasks in a very short time. Memory is the system of component of the computer in which information is stored. There are two types of computer memory: RAM and ROM. RAM (random access memory) is the volatile computer memory, used for creating loading, and running programs and for manipulating and temporarily storing data; ROM (read only memory) is nonvolatile, nonmodifiable computer memory, used to hold programmed instructions to the system. The more memory you have in your computer, the more operations you can perform that is the faster it works. Storage hardware The purpose of storage hardware is to store computer instructions and data in a form that is relatively permanent and. Storage hardware serves the same basic functions as do office filing systems except that it stores data as electromagnetic signals. The most common ways of storing data are Hard disk (HDD), floppy disk and CD-ROM. Hard disk is a rigid disk coated with magnetic material, for storing programs and relatively large amounts of data. Floppy disk (diskette) — thin, usually flexible plastic disk coated with magnetic material, for storing computer data and programs. There are two formats for floppy disks: 5.25″ and 3.5″. 5.25″ is not used in modern computer systems because of it relatively large size, flexibility and small capacity. 3.5″ disks are formatted 1.44 megabytes and are widely used. CD-ROM (compact disc read only memory) is a compact disc on which a large amount of digitized read-only data can be stored. CD-ROMs are very popular now because of the growing speed which CD-ROM drives can provide nowadays. Output hardware The purpose of output hardware is to provide the user with the means to view information produced by the computer system. Information is output in either hardcopy r softcopy form. Hardcopy output can be held in your and, such as paper with text (word or numbers) or graphics printed on it. Softcopy output is displayed on a monitor. Monitor is a component with a display screen for viewing computer data, television programs, etc. Printer is a computer output device that produces a paper copy of data or graphics. Modem is an example of communication hardware — in electronic device that makes possible the transmission of data to or from computer via telephone or other communication lines. Hardware comes in many configurations, depending what the computer system is designed to do. Hardware m fill several floors of a large office building or can fit on your lap. SOFTWARE A computer to complete a job requires more than just the actual equipment or hardware we see and touch. It requires Software — programs for directing the operation of a computer or electronic data. Software is the final computer system component. These computer programs instruct the hardware how to conduct processing. The computer is merely a general- purpose machine which requires specific software to perform a given task. Computers can input, calculate, compare, and output data as information. Software determines the order in which these operations are performed. Programs usually fall in one of two categories: system software and applications software. System software controls standard internal computer activities. An operating system, for example, is a collection of system programs that aid in the operation of a computer regardless of the application software being used. When a computer is first turned on, one of the system programmes is booted or loaded into the computers memory. This software contains information about memory capacity, the model of the processor, the disk drives to be used, and more. Once the system software is loaded, the applications software can be brought in. System programmes are designed for the specific pieces of hardware. These programmes are called drivers and coordinate peripheral hardware and computer activities. User needs to install a specific driver in order to activate a peripheral device. For example, if you intend to buy a printer or a scanner you need to worry in advance about the driver programme which, though, commonly goes along with your device. By installing the driver you «teach» your mainboard to «understand» the newly attached part. However, in modern computer systems the drivers are usually installed in the operating system. Applications software satisfies your specific need. The developers of application software rely mostly on marketing research strategies trying to do their best to attract more users (buyers) to their software. As the productivity of the hardware has increased greatly in recent years, the programmers nowadays tend to include as much as possible in one programme to make software interface look more attractive to the user. These class of programmes is the most numerous and perspective from the marketing point of view. Data communication within and between computers systems is handled by system software. Communications software transfers data from one computer system to another. These programmes usually provide users with data security and error checking along with physically transferring data between the two computer/s memories. During the past five years the developing electronic network communication has stimulated more and more companies to produce varios communication software, such as Web-Browsers for Internet. OPERATING SYSTEMS When computers were first introduced in the 1940’s and 50’s, every programme written had to provide instructions that told the computer how to use devices such as the printer, how to store information on a disk, as well as how to perform several other tasks not necessarily related to the programme. The additional programme instructions for working with hardware devices were very complex and time-consuming. Programmers soon realized it would be smarter to develop one programme that could control the computer’s hardware, which others programmes could have used when they needed it. They created the first operating system. Today, operating systems control and manage the use of hardware devices such as the printer or mouse. They also provide disk management by letting you store information in files. The operating system also lets you run programmes such as the basic word processor. Lastly, the operating system provides several of its own commands that help you to use the computer. DOS is the most commonly used PC operating system. DOS is an abbreviation for disk operating system. DOS was developed by a company named Microsoft. MS-DOS is an abbreviation for «Microsoft DOS». When IBM first released the IBM PC in 1981, IBM licensed DOS from ^Microsoft for use on the PC and called it PC-DOS. From the users perspective, PC-DOS and MS-DOS are the same, each providing the same capabilities and commands. The version of DOS release in 1981 was 1.0. Over the past decade, DOS has undergone several changes. Each time the DOS developers release a new version, they increase the version number. Windows NT (new technology) is an operating system developed by Microsoft. NT is an enhanced version of the popular Microsoft Windows 3.0, 3.1 programmes. NT requires a 386 processor or greater and 8 Mb of RAM. For the best NT performance, you have to use a 486 processor with about 16 Mb or higher. Unlike the Windows, which runs on top of DOS, Windows NT is an operating system itself. However, NT is DOS compatible. The advantage of using NT over Windows is that NT makes better use of the PC’s memory management capabilities. OS/2 is a PC operating system created by IBM. Like NT, OS/2 is DOS compatible and provides a graphical user interface that lets you run programmes with a click of a mouse. Also like NT, OS/2 performs best when you are using a powerful system. Many IBM-based PCs are shipped with OS/2 preinstailed. UNIX is a multi-user operating system that allows multiple users to access the system. Traditionally, UNIX was run on a larger mini computers to which users accessed the systems using terminals and not PC’s. UNIX allowed each user to simultaneously run the programmes they desired. Unlike NT and OS/2, UNIX is not DOS compatible. Most users would not purchase UNIX for their own use. Windows 95 & 98, are still the most popular user- oriented operating systems with a friendly interface and multitasking capabilities. The usage of Windows95 and its enhanced version Windows 98 is so simple that even little kids learn how to use it very quickly. Windows 95 and 98 are DOS compatible. The new series of operating system by Microsoft are Windows Millenium, Windows 2000 and Windows XP. Each of these new products is addressed to the both corporate and private clients. New strategy of the Microsoft is aimed at creating «a one for all» product, which will be useful for both the beginners and advanced users. WINDOWS 98 Windows 98 is an operational system with an easy interface based on the expanding windows principle which uses icons to graphically represent files and their types, Windows 98 is the enhanced version of Windows95. Windows 98 makes the way you and your computer interact easy. Most everyday tasks are now easier to accomplish than ever before. For example, the second mouse button has become a powerful weapon. The old Windows 3.0 Programme Manager and File Manager have been replaced. The desktop tools that replace them are very like those found on a Macintosh. For example, there is a Recycle Bin that makes it easier to recover accidentally deleted files. Your computer probably will crash and buzz less running Windows 98 than it did with Windows 3,1 and 3.0 or even DOS. Most memory related problems have been removed. Built-in networking features make it easy to reliably share files with co-workers across the room or across the world. Still you can run DOS programmes and older Windows applications but most users will probably want to spend most of their time using Windows 98 applications instead. Microsoft says that it is moving forward to the time when we’ll all think more about our data and less about the specific name-brand programmes used to create them. Window 98 plug-and-play capability makes it easy to upgrade your computer hardware. And portable computer users will like what Microsoft has done to make their lives calmer. ^ A new Windows shortcuts capability makes it easy to reach frequently used files and other necessities; A new Find feature helps you to locate and examine the contents of files in a flash. Most of this is accomplished without sacrificing performance. In fast, many things (like printing) usually happen faster now, due to 32-bit support and other Windows 98 advancements.
