Chapter 10

Monitor

PCs use one of two monitor technologies: a traditional "glass bottle" CRT monitor or a flat-panel display (FPD) that uses LCD technology.

Chapter 10.1: Monitor Overview

Chapter 10.2: How to Choose a Monitor

Monitor Overview

Monitor is the display device. Many times per second, the video card sends signals out to the monitor. The information video card sends controls which dots are lit up and how bright they are, which determines the picture you see.

Color monitors can display anywhere from 16 to over 1 million different colors. Color monitors are sometimes called RGB monitors because they accept three separate signals -- red, green, and blue.

The resolution of a monitor indicates how densely packed the pixels are. In general, the more pixels (often expressed in dots per inch), the sharper the image. Most modern monitors can display 1024 by 768 pixels, the SVGA standard. Some high-end models can display 1280 by 1024, or even 1600 by 1200.

How to Choose a Monitor

If you're a graphics professional, you may prefer a CRT monitor because they are said to show more realistic colors. However, the latest high-end LCDs can also give equal color quality.

If you with text most of the time, a LCD is a good choice because the various pixels that you find on a LCD will have nicely defined edges. This gives sharp and focus letters on the screen.

Chapter 9

Cases and Power Supplies

A computer's case is more than a box. The case includes the drive cage, the internal compartment that holds disk drives, and almost always the power supply, among other features, all of which we discuss in this chapter.

Chapter 9.1: Cases

Chapter 9.2: Power Supplies

Cases

Most people think of a case as merely the enclosure that holds a PC together. That view is reasonable for people who buy a PC and never open the case, but anyone who builds or upgrades PCs soon realizes that not all cases are created equal. This section describes what you need to know about cases.

Chapter 9.1.1: Cases Overview

Chapter 9.1.2: Case Components

Chapter 9.1.3: Types of Case

Chapter 9.1.4: How to Choose a Case

Cases Overview

The computer case is your computer's housing. You need this to store your components, the largest of which is your motherboard. A good quality case can have a big impact on the performance and durability of the computer. Cases sold have to meet requirements for shielding against both external RFI and interference to external devices that is generated by the computer.

Good cases are designed to provide for proper airflow to keep the components from overheating. Well made cases do not have a thin tinny feel or sound when you tap on them. They have rolled edges to prevent injury. Panels should fit together well without requiring excessive effort. When the computer is running, a good case does not make excessive vibration noises. Other attributes of good cases include ease in opening and ease in accessing internal components.

Case Components

Cases come with various components, as shown in below figure.

Most of these components are self-explanatory. Drive bays are areas in the front for installation of removable media (CD, DVD, floppy, Zip, etc.). The 5 1/4-inch bays are for all but the floppy drives. Cases usually come with small speakers, which are there to provide very basic sounds to the user. About all these speakers play are warning beeps and the sound of a modem connecting. These speakers are very important, because multimedia speakers don't work before Windows has booted, if Windows is in Safe Mode, or if there is a problem with the sound card.

While many older PCs had key locks, few newer ones do. Locking a computer prevents it from being powered on. The most important indicator lights are the ones that show that power is on and that the main hard drive is active. The hard drive indicator is helpful to show if the hard drive is running too much, or if the computer is locked up. On recent cases, the only button is the power button. Older cases might have a Reset button, which simply turns power off and on, and a "Turbo" button. Leave the Turbo button in the On position unless a tech support technician tells you to turn it off.

Chapter 8

Floppy Drive and CD-ROM Drives

Here you will learn Floppy Disk, CD-Rom and CD Writers.

Floppy Disk Drives

A 3.5" square holding a flexible magnetic disc that holds information or data. You need a floppy drive to read the floppy. A floppy disk can hold only 1.44 megabytes, but it is portable and allows you to make copies of your files.

CD-ROM Drives

A CD-ROM drive used to be an 'optional extra' in computers - it is no longer so. Most software packages come in CD format, so you must have a CD-ROM drive to read them. Typically, CD-ROM drives today need to be at least 24X speed to keep up with the newer software applications out there.

A CD drive connects to the computer motherboard through two types of cables. The older and more common connection is through the IDE Ribbon cable. Recently SATA (Serial ATA) drives have been produced and will gradually become more common. The benefits of having SATA cables is that they are smaller and the transfer rate is higher.

Floppy drives were the main source of data transfer and files were small enough to fit on them. However, today even CD drives are getting out of date and are fast being replaced by the DVD ROM and DVD RW Drives.

Chapter 7

Input Devices

Input devices are devices that allow the user to input data into a computer. The most obvious input devices are Mouse and keyboards.

Keyboards

The keyboard is the main input device for most computers. There are many sets of keys on a typical “windows” keyboard. On the left side of the keyboard are regular alphanumeric and punctuation keys similar to those on a typewriter. These are used to input textual information to the PC.

A numeric keypad on the right is similar to that of an adding machine or calculator. Keys that are used for cursor control and navigation are located in the middle. Keys that are used for special functions are located along the top of the keyboard and along the bottom section of the alphanumeric keys.

Keyboards are mainly divided into two types:

1. Multimedia keyboard.

2. Ordinary Keyboard.

Chapter 6.4

Network Adapter

Considering how complicated networking can be, network adapters are rather simple.

Network Adapter Overview

A network interface card, more commonly referred to as a NIC, is a device that allows computers to be joined together in a LAN, or local area network. Networked computers communicate with each other using a given protocol or agreed-upon language for transmitting data packets between the different machines, known as nodes. The network interface card acts as the liaison for the machine to both send and receive data on the LAN.

The most common language or protocol for LANs is Ethernet, sometimes referred to as IEEE 802.3. A lesser-used protocol is Token Ring. When building a LAN, a network interface card must be installed in each computer on the network and all NICs in the network must be of the same architecture. For example, all must either be Ethernet cards, Token Ring cards, or an alternate technology.

An Ethernet network interface card is installed in an available slot inside the computer. The NIC assigns a unique address called a MAC (media access control) to the machine. The MACs on the network are used to direct traffic between the computers. The back plate of the network interface card features a port that looks similar to a phone jack, but is slightly larger. This port accommodates an Ethernet cable, which resembles a thicker version of a standard telephone line. Ethernet cable must run from each network interface card to a central hub or switch. The hub or switch acts like a relay, passing information between computers using the MAC addresses and allowing resources like printers and scanners to be shared along with data.

Chapter 6.3

Modem

A modem, is a device that connects a computer to a standard analog telephone line, the kind to which your telephone is connected.

Modem Overview

A device that translates data from your PC into a form that can be sent to other computers over regular phone lines. The modem also receives signals from other computers and converts it into something your computer can understand. A modem is the device most home computers use to connect to the Internet. A Modem converts digital information into sound so that it may be transmitted over telephone lines. When the modem hears this sound on the other end it converts the sound back into digital information.

Chapter 6.2

Sound

Chapter 6.2: Sound Adapter

Sound Adapter

The basic purpose of sound cards is to allow the user to hear sounds played by the OS and programs, along with music from audio CDs and other audio files, plus sound from DVD and other types of videos. In addition, these allow for voice communication using software such as Yahoo Messenger and Windows Messenger.

Sound Adapter Overview

The sound card is an essential component in the PC, since it translates digital signals into analog audio for your listening pleasure. Well, that's true, if you want to play games or run multimedia applications in your PC. Otherwise, it may not be necessary, especially in business environments.

With a sound adapter and appropriate software, a PC can perform various tasks, including:

Playing audio CDs, either directly or from compressed digital copies of the CD soundtracks stored as MP3 or Ogg Vorbis files on your hard disk

Playing stereo music, sound effects, and/or voice prompts in games, education, training, and presentation software, as well as for operating system prompts, warnings, and other events

Capturing dictation to a document file, adding voice annotations to documents, or controlling applications using voice/speech recognition software

Supporting audio conferencing and telephony across a LAN or the Internet

Supporting text-to-speech software that allows the PC to "read" text aloud, aiding children who cannot read and people who are visually impaired

Chapter 6

Video

Here you will learn about Video Adapter.

Video Adapter

Many computers come with video built into the motherboard. However, many motherboards don't have built-in video, and some that do also have AGP slots for additional or replacement video adapters.

Chapter 6.1.1: Video Adapter Overview

Chapter 6.1.2: How to Choose a Video Adapter

Video Adapter Overview

A computer video adapter is placed in the motherboard, where it transfers video signals through a cable to your monitor. The video adapter can either be built into the motherboard or be a separate card that is placed in either the AGP or PCI-Express Slot.

Chapter 5

Hard Disk Drives

Hard disks consist of one or more magnetic disks contained in a box. They are used as storage media in the PC, where you store programs and other digital data.

Chapter 5.1: Overview of Hard Drives

Chapter 5.2: How to Choose a Hard Drive

Overview of Hard Drives

The hard disk (or hard drive) is the permanent storage area of your computer. It stores information whether the computer is on or off. A hard drive is a mass storage device found in all PCs (with some exclusions) that is used to store permanent data such as the operating system, programs and user files.

The data on hard drives can be erased and/or overwritten, the hard drive is classed as a non-volatile storage device which means it doesn't require a constant power supply in order to retain the information stored on it (unlike RAM).

Inside every hard drive are small round disk-like objects made of either an aluminum/alloy or a glass/ceramic composite, these are called platters, each platter is coated with a special magnetic coating enabling them to store data magnetically. Hovering above these platters are read/write heads that transfer data to and from the platters.

Hard drives come with many different storage capacities, hard drive capacity is measured in bytes, with common capacities being stated in MB (Megabytes) and GB (Gigabytes).

Chapter 4

Memory

RAM is our working memory storage. All the data, which the PC uses and works with during operation, are stored here. Data are stored on drives, typically the hard drive. However, for the CPU to work with those data, they must be read into the working memory storage, which is made up of RAM chips.

Chapter 4.1: Memory Overview

Chapter 4.2: Memory Types

Chapter 4.3: Memory Installation

Memory Overview

RAM (Random Access Memory) is the basic working memory of your computer system. A computer used RAM to hold volatile (Temporary) instructions and data needed for processing. Volatile simply means that it is not permanent, which means anything written to RAM will be loses if the machine loses power or if it's turned off.

Another key point about RAM is that data stored init can be accessed much more quickly than data retrieved from the hard disk. Theoretically data retrieved from RAM is accessed 100 to 300 times faster then the same information from a hard disk, optical drive, or a floppy.

Memory is measured in bytes, so you'll often encounter the terms megabyte (MB) and gigabyte (GB) in describing RAM sizes (a megabyte is a million bytes; a gigabyte, a billion). RAM is something that you do not want to skimp on. You can choose a slower processor, but with RAM you want as much as you can get.

Memory Types

There are many types of memory used today. They differ mainly in available speeds and cost. Motherboards are limited to one type of memory. Common memory types include:

SDRAM

Almost all systems used to ship with 3.3 volt, 168-pin SDRAM DIMMs. SDRAM is not an extension of older EDO DRAM but a new type of DRAM altogether. SDRAM started out running at 66 MHz, while older fast page mode DRAM and EDO max out at 50 MHz. SDRAM is able to scale to 133 MHz (PC133) officially, and unofficially up to 180MHz or higher. As processors get faster, new generations of memory such as DDR and RDRAM are required to get proper performance.

DDR Memory (184-pin DIMMS)

These were introduced in 2002 to replace the earlier SDRAM format. To use this type of memory you need a 184-pin socket for the module to fit into.

DDR Memory is available in different speeds of PC2100, PC2700, PC3200 (DDR400), and PC4000 (DDR500). The modules can be used singly or how desired however you cannot mix different speeds together.

Chapter 3

Motherboard

The motherboard is the heart of a PC. Some manufacturers use the terms system board, planar board, baseboard, or main board, and Intel calls its motherboards desktop boards. No matter what you call it, the motherboard defines the PC. It provides the common link to all other components inside the PC, including the CPU, memory, disk drives, video and sound adapters, keyboard, mouse, and other peripheral components.

Chapter 3.1: Motherboard Overview

Chapter 3.2: Identifying a Motherboard

Chapter 3.3: How to Choose a Motherboard

Motherboard Overview

The motherboard is the main circuit board inside your PC. Every components at some point communicates through the motherboard, either by directly plugging into it or by communicating through one of the motherboards ports.

The motherboard is one big communication highway. Its purpose inside your PC is to provide a platform for all the other components and peripherals to talk to each other.

Modern motherboards come with the following features:

Processor slot : Processor slot is used for processor.

Memory banks : Memory banks are used for RAM modules.

AGP slot : AGP slots are used for graphics accelerators.

PCI slots : PCI slots are used to provide connectivity for PCI cards such as modems and sound cards.

IDE : IDE are used to connect and control IDE devices such as hard drives and CD-ROM drives.

USB ports : USB ports are used to connect USB devices.

These are just some of the features that a motherboard may have as standard, some motherboards come with integrated components such as a sound card, graphics card, modem, NIC (Network Interface Card) and more.

Identifying a Motherboard

While many motherboards are easily identifiable, a few aren't. Here are some identification methods:

Look for the brand name, model number, and revision number printed on the circuit board.

Look for a sticker underneath the lowest expansion slot. It might not be visible without disassembling the computer and removing the board, or at least by using a small mirror on a handle.

On bootup, look on the first screen if the information does appear, you won't have long to see it unless you press the Scroll Lock key.

The information might appear somewhere in the BIOS.

If the computer is a brand-name computer, you can often find the board used by going to the computer manufacturer's Web site.

How to Choose a Motherboard

As everything you have on the PC at some point needs the motherboard, you need to consider these components when buying a motherboard. For example, if you have a lot of devices with a PCI interface that you wish to use, there is little point buying a motherboard that only offers you 3 PCI slots. Like wise with memory, you have to make sure that there are enough slots for the amount of memory you have or wish to have.

The motherboard also needs the correct type of interface for your Memory, Graphics card, Hard disks and other items as well. You will find that most motherboards offer everything you need however it needs checking on when buying. Its especially important to pay detail to your motherboard if you want to use older components, which a new motherboard may or may not support.

The major difference between motherboards that support the same CPU is the model of the chipset. Different chipsets offer different performance and different features in terms of memory support, AGP port speed, Multiplier numbers, Bus speeds and much more.

When you are choosing one motherboard you have to consider:

What's Your Processor?

First and most important thing to consider when buying your motherboard - what CPU or processor are you using? Motherboards are made differently, not all motherboards will support all CPUs.

What CPU you select will determine the type of motherboard you get. For example, if you want to use an Intel Pentium 4 CPU, the motherboard you select must be able to support that brand and model of CPU. The motherboards are also designed to support specific speeds for a CPU, so make sure it can support the speed of the processor as well.

What is a Motherboard Chipset?

What is a chipset? Well, chipsets are the main controllers on the motherboard - they allow the CPU to interface with the various components and expansion cards installed.

When choosing your chipset, always bear in mind the type of memory supported by the motherboard. Make sure that the board supports the type and amount of RAM you need. Generally, choosing a chipset that supports high speed memory will allow your system to perform better.

Expansions Slots and Connectors

If you intend to various peripherals to the computer, then the number and type of expansion slots and connectors is important. By default, most motherboards these days have USB 2.0 ports incorporated into their design. If you intend to buy expansion cards, make sure the board comes with an ample number of PCI slots.

Other Features

These days, most motherboards have a whole host of extra features loaded into them. These can include things such as on-board VGA, audio, a RAID controller, Modem or Network Card.

Chapter 2

Processor Overview

The Central Processing Unit, Which is often referred to as the "Processor" is the brain of the computer. The chip that performs the majority of calculations and instructions needed to make your computer run. Without this chip, no other function of the PC is possible. The processor is attached to the motherboard (Processor slot).

The computer's speed or clock rate is integral to its overall design. The computers clock rate is the frequency at which it can execute a set of instructions. Computer clock rates are measured in Megahertz (million of clock ticks per second).

There are two types of speeds that should be considered when evaluating the system performance:

Internal clock speed - Is the speed at which the processor can obtain information within itself, like with internal cache and registers. (Pentium III 800 MHz. the 800 MHz is the internal clock speed)

External clock speed - Is the speed at which the CPU communicates with components outside itself.

Some commercially available processors:

Pentium I-IV

1. Celeron

2. Athlon

3. Duron

4. Cyrix C3

5. Itanium (64 bit)

6. Opteron (64 bit)

Chapter 1.2

Chapter 1.2: Software Components

Many people think of a PC as comprising solely physical hardware, but hardware is just a useless pile of silicon, metal, and plastic unless you have software to make it do something. Software is a set of detailed instructions that allow a computer to perform a task or group of tasks. Software is usually categorized as being one of three types:

Applications programs : Applications programs are what most people think of when they hear the word software. These programs are designed to perform specific user-oriented tasks, such as creating a word processing document or spreadsheet, browsing the Web, reading and replying to email, managing your schedule, creating a presentation, or recovering a deleted file. Hundreds of thousands of applications programs are available, from comprehensive office suites such as Microsoft Office, to vertical market packages such as medical office billing software, to single-purpose utilities such as WinZip.

Basics of Computer Hardware

Introduction

Your PC (Personal Computer) is a system, consisting of many components. Some of those components, like Windows 7, and all your other programs, are software. The stuff you can actually see and touch is hardware.

Chapter 1.1: Hardware Components

Chapter 1.2: Software Components

Chapter 1.1: Hardware Components

One of the great strengths of the PC architecture is that it is extensible, allowing a great variety of components to be added, thereby permitting the PC to perform functions its designers may never have envisioned. However, most PCs include a more-or-less standard set of components, including the following:

Motherboard :  The motherboard, described in Chapter 3, is the heart of a PC. It serves as "Command Central" to coordinate the activities of the system. Its type largely determines system capabilities.

Processor : The processor or CPU (described in Chapter 2) is the engine that drives the PC. The CPU you use determines how fast the system runs and what operating systems and other software can run on it.

Easy To Learn

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Lesson 4.7

4.7       WHAT YOU HAVE LEARNT

In this lesson we discussed the importance and modes of communication through computers. Computers can communicate with one another through computer networking. There are two types of computer network: LAN and WAN. We discussed about the physical arrangements of computer and peripherals in network topology. There are three types of network topology: star topology, bus topology and ring topology. Also we discussed about Internet and e-mail.

4.8       TERMINAL QUESTIONS

1.   What is computer Network?   What are its main objectives?

2.   Differentiate between analog and digital transmission of data.

3.   Explain in brief different communication media.

4.   What is the difference between simplex and full-duplex transmission?

                                                                                                                                               

4.9       FEEDBACK TO IN-TEXT QUESTIONS                       

IN-TEXT QUESTIONS 1

1.      The data communication software instructs computer systems and devices as to how exactly data is to be transferred from one place to another. The procedure of data transformation in the form of software is commonly called protocol.

2.      In asynchronous transmission data is transmitted character by character as you go on typing on a keyboard. On the other hand, in the synchronous mode, the saved data is transmitted block by block.

3.          (a) True             (b) False          (c) True            (d) True           (e) True

Lesson 4.6

4.6       INTERNET

The Internet is a network of networks. Millions of computers all over the world are connected through the Internet. Computer users on the Internet can contact one another anywhere in the world. If your computer is connected to the Internet, you can connect to millions of computers. You can gather information and distribute your data. It is very much similar to the telephone connection where you can talk with any person anywhere in the world.

In Internet a huge resource of information is accessible to people across the world.  Information in every field starting from education, science, health, medicine, history, and geography to business, news, etc. can be retrieved through Internet. You can also download programs and software packages from anywhere in the world. Due to the tremendous information resources the Internet can provide, it is now indispensable to every organisation.

Lesson 4.4

4.4       COMPUTER NETWORK

A computer network is an interconnection of various computer systems located at different places. In computer network two or more computers are linked together with a medium and data communication devices for the purpose of communicating data and sharing resources. The computer that provides resources to other computers on a network is known as server. In the network the individual computers, which access shared network resources, are known as workstations or nodes.

Computer Networks may be classified on the basis of geographical area in two broad categories.

1. Local Area Network (LAN)

2. Wide Area Network (WAN)

4.4.1    Local Area Network

Networks used to interconnect computers in a single room, rooms within a building or buildings on one site are called Local Area Network (LAN). LAN transmits data with a speed of several megabits per second (10⁶ bits per second). The transmission medium is normally coaxial cables.

LAN links computers, i.e., software and hardware, in the same area for the purpose of sharing information. Usually LAN links computers within a limited geographical area because they must be connected by a cable, which is quite expensive. People working in LAN get more capabilities in data processing, work processing and other information exchange compared to stand-alone computers. Because of this information exchange most of the business and government organisations are using LAN.

Lesson 4

LESSON 4

COMMUNICATION AND COMPUTER NETWORK

4.1       INTRODUCTION   

Today computer is available in many offices and homes and therefore there is a need to share data and programs among various computers with the advancement of data communication facilities. The communication between computers has increased and it thus it has extended the power of computer beyond the computer room. Now a user sitting at one place can communicate computers of any remote sites through communication channel. The aim of this chapter is to introduce you the various aspects of computer network.

4.2       OBJECTIVES

After going through this lesson you will be in a position to:

·         explain the concept of data communication

·         understand the use of computer network

·         identify different components of computer network

·         identify different types of network

·         explain communication protocols

·         understand what is internet and email and its uses in modern communication

·         appreciate the use of satellite communication.

Lesson 3.7

3.7  WHAT YOU HAVE LEARNT

In this lesson we discussed about two types of software, namely, system software and application software. System software controls the hardware part of the computer. It is designed for performing tasks such as controlling all operations required to move data into and out of the computer. It communicates with printer, card reader, disk, tapes, etc. and monitors the use of various components like memory, CPU, etc. DOS, UNIX and WINDOWS are three important system softwares. Application software is a set of programs written for specific purpose. Examples of application softwares are MS WORD, Lotus 1-2-3, COBOL, BASIC and FORTRAN. We have discussed about levels of computer language.

3.8   TERMINAL QUESTIONS

1. What is software and hardware?

2. What is computer Language?

3. Name the three different categories of computer languages.

4. What is machine language? Why is it required?

5. What are advantages and disadvantages of machine language .       

6  What is assembly language? What are its advantages over machine languages?

7 What is the difference between source program and object program?

8 What is higher level languages? Why are higher level languages are easier to use.

9   What is compiler? Why is it required?

10      What is interpreter? How does it differ from compiler?

Lesson 3.6

3.6 HIGH LEVEL LANGUAGES

You know that assembly language and machine level language require deep knowledge of computer hardware where as in higher language you have to know only the instructions in English words and logic of the problem irrespective of the type of computer you are using.

Higher level languages are simple languages that use English and mathematical symbols like +, -, %, / etc. for its program construction.

You should know that any higher level language has to be converted to machine language for the computer to understand.

Higher level languages are problem-oriented languages because the instructions are suitable for solving a particular problem. For example COBOL (Common Business Oriented Language) is mostly suitable for business oriented language where there is very little processing and huge output. There are mathematical oriented languages like FORTRAN (Formula Translation) and BASIC (Beginners All-purpose Symbolic Instruction Code) where very large processing is required.

Thus a problem oriented language designed in such a way that its instruction may be written more like the language of the problem. For example, businessmen use business term and scientists use scientific terms in their respective languages.

Lesson 3.5

3.5 WHAT IS LANGUAGE?

You are aware with the term language. It is a system of communication between you and me. Some of the basic natural languages that we are familiar with are English, Hindi, Oriya etc. These are the languages used to communicate among various categories of persons. But how you will communicate with your computer. Your computer will not understand any of these natural languages for transfer of data and instruction. So there are programming languages specially developed so that you could pass your data and instructions to the computer to do specific job. You must have heard names like FORTRAN, BASIC, COBOL etc. These are programming languages. So instructions or programs are written in a particular language based on the type of job. As an example, for scientific application FORTRAN and C languages are used. On the other hand COBOL is used for business applications.

3.5.1  Programming Languages

There are two major types of programming languages. These are Low Level Languages and High Level Languages. Low Level languages are further divided in to Machine language and Assembly language.

3.5.2 Low Level Languages

The term low level means closeness to the way in which the machine has been built. Low level languages are machine oriented and require extensive knowledge of computer hardware and its configuration.

Lesson 3

LESSON   3

LANGUAGE/SOFTWARE

3.1 INTRODUCTION

In the previous lesson we discussed about the different parts and configurations of computer. It has been mentioned that programs or instructions have to be fed to the computer to do specific task. So it is necessary to provide sequence of instructions so that your work can be done. We can divide the computer components into two major areas, namely, hardware and software. Hardware is the machine itself and its various individual equipment. It includes all mechanical, electronic and magnetic devices such as monitor, printer, electronic circuit, floppy and hard disk. In this lesson we will discuss about the other part, namely, software.

3.2 OBJECTIVES

After going through this lesson you will be able to

·     explain the concept  of software

·     distinguish between different types of software

·     differentiate application software from system software

·     define a language

·     differentiate between different types of language

·     distinguish between compiler and interpreter

3.3  WHAT IS SOFTWARE?

As you know computer cannot do anything without instructions from the user. In order to do any specific job you have to give a sequence of instructions to the computer. This set of instructions is called a computer program. Software refers to the set of computer programs, procedures that describe the programs, how they are to be used. We can say that it is the collection of programs, which increase the capabilities of the hardware. Software guides the computer at every step where to start and stop during a particular job. The process of software development is called programming.

You should keep in mind that software and hardware are complementary to each other. Both have to work together to produce meaningful result. Another important point you should know that producing software is difficult and expensive.

3.4  SOFTWARE TYPES

Computer software is normally classified into two broad categories.

·    Application Software

·    System software

Application Software: Application Software is a set of programs to carry out operations for a specific application. For example, payroll is an application software for an organization to produce pay slips as an output. Application software is useful for word processing, billing system, accounting, producing statistical report, analysis of numerous data in research, weather forecasting, etc. In later modules you will learn about MS WORD, Lotus 1-2-3 and dBASE III Plus. All these are application softwares.

Another example of application software is programming language. Among the programming languages COBOL (Common Business Oriented Language) is more suitable for business application whereas FORTRAN (Formula Translation) is useful for scientific application. We will discuss about languages in next section.

System Software: You know that an instruction is a set of programs that has to be fed to the computer for operation of computer system as a whole. When you switch on the computer the programs written in ROM is executed which activates different units of your computer and makes it ready for you to work on it. This set of program can be called system software. Therefore system software may be defined as a set of one or more programs designed to control the operation of computer system.

System software are general programs designed for performing tasks such as controlling all operations required to move data into and out of the computer. It communicates with printers, card reader, disk, tapes etc. monitor the use of various hardware like memory, CPU etc. Also system software are essential for the development of applications software. System Software allows application packages to be run on the computer with less time and effort. Remember that it is not possible to run application software without system software.

Development of system software is a complex task and it requires extensive knowledge of computer technology.  Due to its complexity it is not developed in house. Computer manufactures build and supply this system software with the computer system. DOS, UNIX and WINDOWS are some of the widely used system software. Out of these UNIX is a multi-user operating system whereas DOS and WINDOWS are PC-based. We will discuss in detail about DOS and WINDOWS in the next module.

So without system software it is impossible to operate your computer. The following picture is shown in Fig. 3.1 relation between hardware, software and you as a user of computer system.

IN-TEXT QUESTIONS 1

1.   What are program, programming and software?

2. Differentiate between system software and application software.

3.   Write True or False

   (a) The set of instructions given to the computer is called programming.

    (b) Application Software is a set of programs to carry out operations for a specific application.

     (c) UNIX is a multi-user operating system.