SoftwareSoftware

The set of instructions which are used to perform specific task is called software. Or

The set of instructions that tells the computer what to do is called software.

Examples● Microsoft word● Microsoft excel● Windows xp etc.

HardwareHardware

Physical parts of the computer is called hardware. These are seen able and touch able.

Examples● Key board● Mouse● Printer● Mother board● Hard disk etc.

Relationship between hardware & Relationship between hardware & softwaresoftware

● In order to produce useful output the hard ware and soft ware must work together.

● Both are complementary to each other.● No useful can be obtained its own with out hard ware if

soft ware is not used.● Example is a cassette player.● And remember that hardware is necessary but soft ware is

vital.● Soft ware production is difficult and expensive.● Hard ware is a one time investment.

Types Of SoftwareTypes Of Software

Computer software is normally classified into four broad categories.

● Application software● Custom made software● System software● Programming and Translation software

Application Software

● Computer soft ware that written for some particular application is called computer application software.

● Application software are also called general purpose or “off- the- shelf” package.

● They provide solution to a range of different problems related to a particular type of application.

Examples ● Word processing● Spread sheets● Database management system● Presentation designers

Drawbacks Of Application Software

1- Bloat ware (Too many features)

● Some soft ware has become so crowded or bloated with feature that it has led to the term bloat ware

● The reason to introduce to so many feature is that the customer rush to buy new one to remove his old one.

Example When micro soft office came on the market supplanting

office 97, it contained more than 6000 commands, far more than the few dozen or even few hundred that most people would use.

2- Shovel ware (Full of flaws)

● Soft ware makers are in such a hurry to ship or shovel their products out the door to the market that it has inspired a new word” shovel ware” and a lot of shovel ware are developed so hastily that it doesn’t work right

● Sometimes an applications program doesn’t perform because of incompatible standard with other parts of the computer system

● For instant it is not compatible with newer or older version of operating System

Custom Made Software

● Custom made soft ware are also called special purpose “bespoke” software.

● These soft ware are written to meet the processing needs of an individual or an organization.

● These software's are prepared for the computing need of a company when required soft ware is not available in the market.

● Creating a software is the responsibilities of “MIS” department.

● In house changing are also made when commercial soft ware requires extensive reprogramming

● Custom made soft ware are prepared when company required security and that security can not made by commercial packages Examples are payroll, inventory, accounts, sales, production, marketing.

System Software

● System software is a set of one or more programs, designed to control the operation of a computer system.

● System soft ware controls the hard ware● Application software can be able to run through system soft

ware ● They are general programs written to assist humans in the

use of computer system.● System soft ware communicate with peripheral devices

(hard ware).● the program include in system soft ware are called system

programs and a person who prepare system soft ware is called system programmer.

● Good systems software allows application packages to be run on the computer with less time and effort.

● A computer would be very ineffective and most likely impossible to operate.

Types Of System Software

1- Operating System

● Operating system is a collection of control, processing, and data management programs specially designed to manage the resources of computer system.

● OS is also be defined as the Resource Manager● Modern computer system are so fast that they need internal

control ● The complexity of system demand that jobs are controlled

in what they are allowed to do for the sake of security although over all user is provided with greater flexibility.

Leading operating systems for PC

a) DOS (Disk Operating System)

● DOS was most popular operating system for● 16 bit Pc’s.● It is used with older PCs based on the “IBM”● PC standard because so much application soft

ware are written for system using Dos.● DOS does not support multitasking and limits● The size of the program in memory to 640K.

b) Windows

● Microsoft windows 3.x is an operating environment that lays a graphical user interface shell around the Dos operating system and extended Dos capabilities.

● Different version of windows are (3.0,3.1,3.11 for work group)

● Windows support limited forms of multitasking and networking but share the memory limitation of Dos.

● Early windows has some problem with application crashes

● Microsoft windows 98 and windows 95 are genuine 32 bit operating systems.

● A 32 bit operating system can run faster than DOS, which could only address data in 16 bit chunks.

● Windows 98 and windows 95 provide graphical user interface (GUI).

● Windows can perform multitasking and multithreading (the ability to manage multiple independent task simultaneously).

● Windows 98 also provide the capabilities of networking. ● Windows 98 is more effect with internet as compare to

windows 95.● It support the function of DVD, video conferencing,

cameras, scanners, TV tuner adapter cards and joy stick.● It integrate with web browser soft ware.● It gives the facilities to view hard disk and web browsing.

c) Windows NT:

● Windows NT is another 32 bit operating system● It supported large networks.● Windows NT is a multitasking, multi user,

multiprocessing network operating system with graphical user interface.

● Windows NT support programs written for Dos and windows

● It can support multiprocessing with multiple CPUs● There are two version of Windows NT workstation and

Windows NT Server.

d) Windows CE:

● Windows compact edition(CE) has some of the capabilities of windows including its graphical user interface.

● It is used in small hand held computer, personal digital assistance or wireless communication devices such as pagers and cellular phones.

● It requires very little memory.● Non pc devices use this operating system to share

information with windows based PCs and to connect to the internet.

e) OS/2:

● OS/2 is designed to run on many recent IBM and IBM compatible microcomputers.

● OS/2 is a 32 bit operating system for powerful IBM compatible PCs with intel microprocessors.

● OS/2 is used at where complex , memory intensive application are required or where networking or multitasking are require.

● OS/2 support applications that runs under windows and Dos and has its own graphical interface.

● It has two version OS/2 warp and OS/2 warp server.● OS/2 warp is for personal users● OS/2 warp server has ability like windows NT for

supporting networking.

f) UNIX

● It is a multitasking operating system for multiple users that has built in networking capabilities and version that can run on all kind of computer.

● Unix is an interactive, multi- user, multitasking operating system developed by Bell Laboratories in 1969 to help scientific researchers share data.

● Unix is highly supported to networking. ● Unix is design for mini computers but now has version for

PCs , work stations and server computers. ● It can store large number of files.● Unix is powerful but very complex, with bulk of

commands. ● Graphical user interface has developed for Unix.● Unix also generate some security problems because

multiple jobs and users can access the same file simultaneously.

g) MAC OS

● Mac OS the operating system for the Macintosh computer has features of multi tasking as well as powerful multimedia and networking capabilities and a mouse driven graphical user interface.

● The Macintosh operating system runs only on Apple Macintosh computers or on Mac clones.

● Apple kept Macintosh price high and refused to license any clones, Mac are expensive

Functions of operating system

● Helps in booting up process of the computer.● Checking that the hard ware is functioning properly.● Defines user interfaces.● Scheduling and loading of jobs in order to provide

continuous processing. ● Control of user selection and operation of input/out put

devices and file handling.● Calling into main storage of programs and subroutines as

and when required.

● Opening and closing file and checking of file label.● Maintenance of directories in external storages.● Passing of control from one program to another program

when more than one application is open.● Communication with computer user by means of input and

output devices.● Managing tasks such as multi tasking, multiprogramming,

multi processing and timesharing.

Characteristics of operating system

a) Single User

● The stand alone environment refer to as single user.● One person can communicate one computer only.● The is no net work environment

b) Multi User

● Multi user mean many geographically processing system are connected by telecommunications network and in which messages processing tasks, programs data and other resources between terminals

● Benefit is that sharing of resources in term of hard ware and software.

c) Multi-Programming  

● Multiprogramming permits the running of several programs in sequence

● Multi programming is a basic form of parallel processing in which several programs are run at the same time on a single processor

● There is only one processor, there can be no true simultaneous execution of different programs

● The real power is operating system that executive part of one program, then part of another and so on

● But some times a computer is so overload that its delays the shared nature of the machine more obvious

d) Preemptive Multiprogramming

● Preemptive multi programming is a task in which a computer operating system uses some criteria to decide how long to allocate to any one task before giving another task a turn to use operating system

● The act of taking control of the operating system from one task and giving it to another task is called preempting (block, chunk, slab)

● The common criterion for preempting is simply elapsed time or time slicing

● In some operating systems some applications can be given higher priority than other applications

e) Time Sharing:

● Use of computer by many users each having its own input and out put devices and accessibility to the computer at the same time

● The computer in such cases gives each user a small but frequently repeated slice of time

● That’s why each user gets the immediate response.● This kind of multi programming is called time sharing

f) Multi Tasking

● Computer hardware (processor) and soft ware that permits more than one programs to run at the same time

● Multitasking required multi processor

g) Multi Tasking

● d

Programming & Translation Software

Language

● A language is defined as a system of communication. ● A discipline that conveys ideas or emotions to one another. ● Every language consist of symbols, characters and usage

rules that permit people to communicate with the computer.

● With the help of computer language a programmer tells computer what to do.

● Writing instruction is called coding

Types Of Languages

There are two types of language. Low Level Languages

Machine Language Assembly Language

High Level Languages Basic Fortran Cobol C C++ Visual basic Java

1- Machine Language

● Machine language is the basic language of the computer representing data as (1’s or o’s) which the computer can run directly.

● It does not need further translation before being executed. ● This is the fundamental language of the computer

because computer can only understand this language.● Basic instruction consist of two part. ● First part consist of operation code what is to be do.● Second part consist of memory location address● Machine language provides economy of instruction but

they are inconvenient to the user.● Machine language required through knowledge of

compute hard ware.

Advantages

● Program written in machine language can be executed very fast by the computer

● Because machine instructions are directly understood by CPU and no translation of program is required

● Machine language written in binary numbers( 1 and o) and that is the language of computer.

● Program written in machine language is no need to further translate

● Less Instruction are required because computer understand it

Disadvantages

● Computer internal structure are different from another type of computer so problem arise.

●  Machine language is difficult to program because either programmer has to learn dozen’ of command or use reference card.

● Also expert programmer is required who knows about hard ware structure of the computer.

● It is difficult to correct or modify machine language programs.

● Checking of machine language program is as difficult write initially.

● Machine language is machine dependent.

● Programmer must know the logical structure of the computer in order to write a good machine language program.

● Writing programs in machine language required expert level of programmer and effort.

● The result of all these produce high cost.● All phases of programming like coding, debugging, testing

is high in machine language.

2- Assembly language

● Assembly language allows a computer user to write program using abbreviation or more easily remembered word instead of binary numbers

● To ease programmer burdens symbols were developed● The assembly language is machine dependent● Program written in assembly language is converted into

machine language with assembler● There is a one-to-one correspondence between the

assembly instruction of source program and the machine instructions of object program

Translation Software

There are three types of translator   

(i) Assembler

(ii)  Compilers

(iii) Interpreters

1- Assembler

● A language that’s use letters and symbols in place of number is called assembly language.

● The translator software that convert assembly language to machine code is called assembler.

● The assembler is a system program that is provide the computer manufacturer

● It is prepare by system programmers with great care.

2- Compilers

● Since computer hard ware is capable of understanding only machine level instructions so there must be a soft ware that convert this high level language into machine level language.

● So compiler is a software that convert high level language into machine language.

● Program written in high level language is called source code.

● When source code is convert to machine code through compiler is called object code.

● This software compile the whole program at once.

3- Interpreters

● Interpreters is another soft ware that convert high level language into machine language.

● It takes one statement of high level language and convert them into machine language.

● Translation and execution alternate for each statement encountered in the high level language program.

● Interpreters translates one instruction and control unit executes the resulting machine code the next instruction is translated and control unit executes the machine code instruction and so on.

Outsourcing

Outsourcing refers to organizations buying in services and expertise rather than employing their own staff to perform functions.Outsourcing practices relate to contractual agreements under which an organization hands over control of part, or all, of the functions of the Information System department to an external party.The contractor provides the resources and expertise required to perform the agreed service, outsourcing is becoming increasingly important in many organizations. The specific objectives for IT outsourcing vary form organization to organization.

Types of outsourcingTypes of outsourcing

Classification Comments

Ad-hoc

The organization has a short-term requirement for increased IS/IT skills. An example would be employing programmers on a short-term contract to help with the programming of bespoke software.

Project Management

The development and installation of a particular IS/IT project is outsourced. For example, a new accounting system.

Partial Some IT/IS services are outsourced. Examples include hardware maintenance, network management or ongoing website management.

Total An external supplier provides the vast majority of an organization’s IS/IT services; eg third party owns or is responsible for IT equipment, software and staff.

Advantage of Outsourcing

● Outsourcing can remove uncertainty about Cost, as there is often a long-term contract where services are specified in advance for a fixed price.

● Long-term contracts encourage planning for the future.● Outsourcing can bring the benefits of economies of

scale. For example, a FM company may conduct research into new technologies that benefits a number of their clients.

● A specialist organization is able to retain skills and knowledge. Many organizations would not have a sufficiently well-developed IT department to offer IT staff opportunities for career development. Talented staff would leave to pursue their careers elsewhere.

● New skills and knowledge become available. A specialist company can share staff with specific expertise between several clients. This allows the outsourcing company to take advantage of new developments without the need to recruit new people or re-train existing staff, and without the cost.

● Flexibility (contracting permitting). Resources may be able to be scaled up or down depending upon demand. For instance, during a major changeover form one system to another the number of IT staff needed may be twice as large as it will be once the new system is working satisfactorily.

● An outsourcing organization is more able to arrange its work on a project basis, whereby some staff will expect to be moved periodically from one project to the next.

Disadvantages of outsourcing

● It is arguable that information and its provision is an inherent part of the business and of management. Unlike office cleaning, or catering, an organization’s IT services may be too important to be contracted out. Information is at the heart of management.

● A company may have highly confidential information and to let outsiders handle it could be seen as risky in commercial and/or legal terms.

● If a third party is handling IS/IT services there is no onus upon internal management to keep up with new development or to suggest new ideas. Consequently, opportunities to gain competitive advantage may be missed. Any new technology or application devised by the third party is likely to be available to competitors.

● An organization may find itself locked in to an unsatisfactory contract. The decision may be very difficult to reverse. If the service provider supplies unsatisfactory levels of service, the effort and expense the organization would incur to rebuild its own computing function or to move to another provider could be substantial.

● The use of outside organization does not encourage awareness of the potential costs and benefits of IS/IT within the organization. If manager cannot manage in-house IS/IT resources effectively, then it could be argued that they will not be able to manage an arrangement to outsource effectively either.