Objectives
- At the end of this lesson, readers should be able to:
- Explain the term software and give examples
- Differentiate between system software and Application software
- Define the term operating system
- Give examples of operating system
- State the functions of operating system
- Differentiate between DOS operating system and window operating system
Introduction
Software is the term used to describe computer programs; it is the blood
that flow through the computer system. Compared with the hard ware, the
software on a given computer is relatively easy to change and it is the
attributes, which give computers their flexibility.
Just as there
are two types of blood cells in human beings performing different functions, so
also we two types of software performing different functions in the computer
system. The first is referred to as System software and the other is the
Application software. All other forms of software come under these two
broad divisions.
A set of instruction of programs designed to efficiently manage the resources
of the computer system is referred to as supporting
system. It is the operating system that makes the computer to understand
the user’s instructions and command. It is the life-wire of a computer
system. It does the loading and scheduling of all activities going on in a
computer system. Some examples of operating system are Disk Operating System
(DOS). Windows Operating System, Linux Operating System , UNIX and Xenis
Operating System etc.
Software Component of a Computer system
Computer
hardware without software can be likened to a vehicle without petrol. A
system can only perform based on a set of given instructions that are to be
followed in sequence, called progam.
Software refers to the collection of all the programs available on a set of
given instructions that are to be followed in sequence, called program.
Software refers to the collection of all the programs available on a computer
system or in a computer installation, Software can be divided into two main
classes namely:
Application software
programs written by the manufacturer to control the smooth running of the computer.
They are programs that enhance the performance operation of computer. It
is divided into four classes of the system namely”
- Operating system
- Translators
- Database management system (DBMS)
- Utilities and service programmers
Application Software: This can be classified into two namely;
User application program and Application Packages
What is Operating system?
An operating system can be defined as the collection of programs which are
resident in the computer memory. It controls the general operations of the
computer system
There are different types of operating system as specified by their operational
performance. The most commonly used operating system are
- Single user operating system
- Multi user operating systems
- Networking operating systems
allows only a single task to be performed at a time. It allows a
single user to operate the machine at a time in an interactive mode and allows
one user program to be in the main store and processed at a time. It does
not allow users program.Examples of a single user operating system include
MSDOS, PCDOS etc.
operating system: Multi-user operating system permits the execution of more
than one task at a time; It shares the system resources to more than one
user by connecting the individual user out the system. Examples are
windows 98, windows meme, Zenix os/2ce.
Networking operating system is used in network environment where users
from different locations are interconnected. Computers are connected to a
large network, such as WAN & INTERNET. Examples of a networking
operating system includes window NT, window 2000, Window DP, novel Netware.
The general functions of the operating system include the following among
others;
- It helps in loading and scheduling of programs to provide continuous
processing and give appropriate response to events - It protects software, hardware and data fro improper sue.
- It manages hardware resource
- It performs the loading of programs form external memory to the main memory
- It provides error correction routine
- It makes communication possible between the users and computer system
- It passes control from one job to another in a multi programming environment
- It handles interrupt malfunctioning.
Disk Operating System
Disk operating
system is the master program of computer, which can be located in the computer
temporary memory called RAM. It allows the various parts of the computer
to communicate with one another. It allows the computer users to copy
files, format disk and print etc.Example of SOS are SDOS (Microsoft Disk
Operating System) PCDOS is a single user operating system.
There are two types of dos command and they are:
- Internal DOS command
- External DOS command
- Internal DOS command
These are command that comes with the new computer; they are the simplest and
most commonly used command. It is an invisible command that resides in
the memory of the computer. Example of |DOS is CLS that resides in the
memory of the computer. Example of Dos are CLS, date, dir, del, cd
prompt md, ver, file copy.etc.
The external command Dos command are read from the disk and loaded into the
memory of the computer before they can be executed. They are command that
have to be purchased and store in the hard disk. Examples of External
command are Format Disk copy, Back up, Restore, print etc.
A window operating system is a graphical user interface that enables you
to communicate with your computer through ICON, MENU, dialog box and
application programs.
Windows operating system is the major part to the system software that controls
the interface between the computer and user. It communicates with
the CPU and gives result on the screen.
The different versions of window are a s follows: window 95, 98, 2000
millennium and window XP. The latter versions are more interactive compared
to the former. Latest versions of windows are coming as technology is
advancing daily.
Advantages of window
operating system over DOS
The window operating system has the following advantages over Dos
Window packages are more interactive compare to DOS
Window packages are easier to learn compare to Dos package (i.e. once you know
about window package you can train yourself on the other windows
packages.
Date and time are easier to correct or change on window system compare
to DOS
A translator is a system program that converts programs written in high or low
level language to machine language.
There are three types of translators namely:
Compiler
Interpreter and
Assembler
Compiler: a complier
converts programs written in high-level language to machine language
Interpreter: An Interpreter does the same work with a compiler but in a
different way.
Assembler: An assembler converts programs written in low-level language
to machine language.
Different between a Compiler and an Interpreter
A compiler converts many instructions in high level language to machine
languages at once whereas an interpreter converts on one – to-one basis.
A compiler is more difficult to write but easy to debug whereas, it is easier
to write an interpreter.
A compiled version of program is likely to run faster than an interpreted
version of the program is likely to run faster than an interpreted version of a
program is executed immediately.
The category of program provides useful service to the computer programs by
providing facilities for performing common computing tasks of a routine
nature. The following are some of the examples of commonly used utility
program.
record of a file in a specified sequence alphabetical, numerical or chronological
order.
two or more already ordered files together to produce a single ordered file.
transferring data form one storage medium to the other, for example from disk
to tape.
core dumps, which is used for detecting and correcting errors in programs
facilities for creation and amendment of program from the terminal.
Summary
In this lesson, I am convinced have learnt that:
Software refers to the collection of all the programs available on a computer
system or in a computer installation. And that Software is divided into
two main classes namely:
Application software
An operating system is the collection of programs which are resident in the
computer memory. It controls the general operations of the computer
system. There are different types of operating system as specified by their operational
performance. The most commonly used operating system are:
Multiuser operating system.
Networking operating system
The function of the operating system include the loading and scheduling of
programs to provide continuous processing and give appropriate response to
events among others.
