COMPUTER SOFT WARE

COMPUTER SOFT WARE

Software is a collection of programs.  The term software is used to describe the complete range of computers programs that convert the general-purpose computer system into one capable of performing a multitude of specific functions.

Program:  This is a set of instructions, commands that are arranged in a logical way which can run a computer.

N.B: If you compare a computer with a human being, the body is similar to hardware of the computer.  What is inside i.e the spirit or life within a human  body is similar to software as regards the computer.

Software is used in contrast to hardware to enable the computer run all the programs installed on a computer.

CATEGORIES OF SOFTWARE

Computer software can be broadly classified into two categories

(a)    System software.  This is software responsible for the operation of a computer.  It is usually supplied by the manufacturer of the computer.  Some of the programs reside inside the ROM and are known as Firmware.

System software consists of the following:

(i) Operating system.

(ii) Programming languages.

(iii) System utilities/Utility programs

System software acts as an interface between the user, application software and hardware.  Two types of system software are the operating system and   utility programs.

(b)   Application software.   These are programs developed to solve the users problems e.g typing a document, internet, designing and graphics e.t.c.  These programs include: word processors, spread sheets, accounting programs e.t.c. Application software which handles the needs of the end user fall into two main categories.

 (i) Special purpose packages. These are also called custom made packages which are written to meet specific needs of an organization that cannot be usually satisfied by other sources of software.

(ii) General purpose packages. These are also called off the shelf packages which may be used for a wide variety of purpose such as word processors, spread sheets, databases, and presentation software e.t.c

N.B:  An application service provider (ASP).  This is a third party organization that manages and distributes software and services on the web.

SOFTWARE CLASSIFICATIONS

 

OPERATING SYSTEMS

An operating system is a program which enables a computer to deal with input  and output, keep a track of what is going on and allocate storage space.

You as user in most cases, you are dealing with exterior parts but when you are using a computer, you can’t look inside to see what is going on but this remains the work of an operating system.

When you are storing on diskettes, you can’t know whether its is full by looking at it but it is the operating system to tell that the disk is full by giving you information on the screen.

There fore operating system (OS) is a set of programs containing instructions that coordinate all activities among computer hardware devices.

EXAMPLES OF OPERATING SYSTEMS

1. DOS (Disk Operating system) This refers to several single user operating systems that were developed in the early 80s for personal computers. The two more widely used versions of DOS were PC-DOS and MS-DOS both developed by Microsoft.

2.  Windows 3.x refers to early three versions of Microsoft windows: Windows 3.0,

     Windows 3.1 and 3.11

3. Windows 95 is a true multitasking operating system that does not require DOS

    to run.

Advantages:

-       An improved graphical user interface.

-       Most programs run faster under the OS.

-       Supports a more efficient form of multitasking

-       Supports networking plug and play, longer file names and e-mail.

-       Take advantage of 32-bit processors.

4. Windows NT workstation

5. Windows 98 is an upgrade to Windows 95 operating system.

Advantages

-       More integrated with Internet.

-       Includes the active desktop interface options.

-       Provide faster system start up and shut down.

-       Better file management.

-       Supports new multimedia technologies such as DVD and WEB TV.

-       Supports the Universal serial bus.

-       Like Windows 95, 98 can also run 16 and 32 bit software.

6. Windows 200 professional is an upgrade of Windows NT operating system.

7. Windows ME (Windows Millennium) is an update version of windows 98  for the consumer that that uses a computer to surf the internet or for entertainment, windows millennium is designed mainly for home users.

8. Windows XP home is an upgrade of windows millennium.  Added features of windows XP home edition includes internet explore 6, acquire, organize and share digital pictures, download, store and playback high-quality music through windows media player.

9. Windows XP professional is an upgrade of windows 200 professional.

Added features include

-       All the capabilities of windows xp home edition.

-       Remotely access a computer, its data and its files from any other computer anywhere.

-       Support for secured wireless network access.

-       Simpler administration of groups of users of computers.

10 Mac OS was the first commercially successful user interface.

11. Windows NT server is designed for client server networks.  The server uses a version called NT server.

12.  UNIX. Is a multi user, multitasking operating system developed in the early 1970s by scientist at Bell laboratories.  A weakness of UNIX is that it has a command line interface and many of its commands are difficult to remember.

13. Linux.  Linux is a popular, free UNIX like multi-tasking operating system. Some versions use command line interface while others use graphical user interface.  The two most popular GIUs available for Linux are GNOME and KDE

14. Windows CE is a scaled-down windows operating system designed for use on wireless communication devices and handheld computers.

FUNCTIONS OF AN OPERATING SYSTEM

(a)    Memory management.  It allocates and assigns items to areas of memory called buffers, while they are being processed to monitor carefully the contents of these items in memory, and to clear these items from memory when they are no longer required by the CPU.

(b)   Spooling of print jobs. With pooling, the print jobs are placed in a buffer instead of being sent immediately to the printer.  As soon as the print jobs are placed in a buffer, the CPU is available to process the next instruction and the computer can be used for other tasks.

(c)    Configuring devices.  In the past, installing a new device often required setting switches and other elements on the motherboards.  Most of the operating systems today support plug and play and can configure devices automatically.

(d)   Monitoring system performance.  A performance monitor is  a program that access and reports information about various system resources and devices. The information in such reports helps a user identify problems with the resources.

(e)    Administering security.  The multi-user system requires each user to log on.  Both successful and unsuccessful log on attempts are often recorded in a file so the system administrator can review who is using or attempting to use the computer.  Some operating systems allow the user to assign passwords to files so that only authorized users can open them.

(f)    Managing storage media and files.  Most operating systems include a file manager program that performs functions related to storage and file management.

N.B

1.  Log on. This is the process of entering a user name and a password into the computer.

2. Password.  A password is a combination of characters associated with the user name that allow a user to access a computer or a network.  Passwords should be easy to remember but not to obvious so that one can guess it easily.  Longer passwords provide greater security than shorter ones.

Do use:

-       At least eight characters if supported by the system.

-       A combination of mixed case letters and digits.

-       A password that can be typed easily without looking at the keyboard.

Do not Use:

-       Your name, birth day, ID card number or telephone number

-       A password of all digits or the entire same letter.

Tips for safeguarding your password.

-       Do not share your password with others.

-       Do not write your password.

-       Change your password frequently.

3. A File manager.  This is a program that performs functions related to storage and file management.

Functions of a file manager

-       Formatting and copying disks.

-       Displaying a list of files on a storage medium.

-       Checking the amount of used space on a storage medium.

-       Copying, renaming, deleting, moving and sorting files.

CLASSIFICATION OF OPERATING SYSTEMS

Based on the number of computers, an operating system can act as an interface. Two types of operating systems have been identified namely:

(a)    Single User systems.   An operating system, which act as an interface for only one user.  It is therefore a single user system.  Ideally all stand alone machines (Computers which are not connected to any other) use this operating system.  An example is Ms Dos.

(b)   Multi-User systems.  The concept of multi-user systems is exactly the opposite of the single user.  A computer system, when act as an interface for more than one user becomes a multi-user environment system.

Depending on the look of the operating system interface, an operating system interface, an operating system can either be character based or graphical user interface based.

GRAPHICAL USER INTERFACE

Graphical user interface allows the user to use menus and visual images such as icons, buttons and other graphical objects to issue commands.  Examples; Windows 95, 98, 2000, NT e.t.c.  Basic components of GUI system include desktop, Menu bar   e.t.c..

Advantages of GIU

▪      It is user friendly because it is easy to learn and work with

▪      There is no need to type and memorise any command language.

▪      The interface is similar for any application.

▪      You are provided with a coloured screen with icons each representing a program.  A mouse may be used.

Disadvantages

▪      It requires a faster memory as well as a faster processor.

▪      It also occupies more disk space to hold all files for different functions.

▪      It is difficult to automate functions for expert users.

COMMAND LINE INTERFACE

With a command line interface, a user types keyboard or press special keys on the keyboard to enter data and instructions.  The set of commands a user uses to interact with the computer is called command language.  Examples are DOS, UNIX, Linux e.t.c …

Advantages of Command line Interface

▪      A command line interface takes up little memory and normally does  not require very fast processor.

▪      Operation is fast because commands can be directly through the keyboard.

▪      Many commands can be grouped together as batch file so that repeatitive tasks can be automated.

Disadvantages of Command line interface

-       A command language has to be learnt and memorized.

-       You are provided with a virtually empty screen with a blinking cursor where commands are keyed and the computer executes them by pressing the enter key.

-        

N.B

1.      A Device driver.   This is a small program that tells the operating system how to communicate with the device.  Each device on a computer (e.g a mouse) has its own specialised set of commands and thus requires its own specific driver.  The operating system loads each devices’s driver when the computer boots up.

2.      Data Base Management system (DBMS).

A data base is a collection of data organized in a way that allows access, retrieval and use of the data.  Common paper data bases include:

●     Telephone books.

●     Dictionaries

●     Recipe cards

●     Television guides.

Computerized data bases in Uganda include:

●     Flight information.

●     Phone inquiry system.

●     Data base in public libraries.

●      

Examples of data base software include;

●     Microsoft visual fox Pro.

●     Borland Base

●     Lotus approach

●     Corel paradox

Data storage is looked after by a special program known as Data Base management system (DBMS) and these makes data available fro use in individual application programs.

ADVANTAGES OF ELECTRONIC DATA BASES OVE MANUAL DATA BASES

(a)    Reduction of data redundancy. Storing most of data in one place means less duplication and less required place.

(b)    Enhancement of data integrity. Because data are centralized, fewer updating errors occur and greater accuracy can be maintained.

(c)    Ensured data independence.  Data are entered, stored, modified and accessed by methods that are not affected by application programs.  Also changes made to data structures usually do not require changes in programs that access the database.

(d)   Improvement of access to data. Data systems allow users to query that database directly without necessarily using an application program.

(e)    Facilities of data sharing and integration.  A database system offers users the ability to combine or to cross-reference data in many different ways.

(f)    Centralization of security. It is easier to limit access to information if it is grouped together instead of being kept in several scattered files.  Many databases must be protected and kept private.

(g)    Reduction of costs. Data entry, storage and development of new application programs are all made more economical.  By eliminating the duplication of data, many organizations can realize substantial savings.