ICT

Computer software is broadly divided into two categories namely:

•      System software

•      Application software System Software.

This consists of programs that control or manage the operation of the computer and its devices. System software serves as an interface between users, the application its software and the computer's hard ware. System software is computer software designed to operate the computer hardware and to provide maintain a platform for running application software. Examples of system software include;

•      The operating system

•      Utility Programs

•      Programming language

OPERATING SYSTEM

This is a set of programs containing instructions that co-ordinate all the activities among hardware resources.

•      In otherwords, an operating system is a computer’s master control program.

•      It provides a user with the tools (commands) that enable him/her interact with the computer.

•      It also acts as a primary controlling mechanism for the computers hardware.

•      Without an operating system, a user cannot run an application program on their computer. Classification of operating system Real-Time operating Systems:

•      Refers to multitasking operating system that aims at executing real-time applications.

•      A real time application is an application that responds to certain inputs extremely quickly.

•      Very fast and relatively small operating systems.

•      Built into a device, not loaded from a disk drive.

•      Used in MP3 players, Medical devices such as medical diagnostics equipment, life-support systems etc.       

Single-User/Single-Tasking Operating Systems:

•      Allows a single user to perform just one task at a time

•      Take up little space on disk

•      Run on inexpensive computers

•      Examples include; MS-DOS and Palm OS for palm handheld computers.

Single-User/Multi-Tasking Operating Systems:

•      Allows a single user to perform two or more functions at once.

•      Commonly used on personal computers.

•      Examples include; Microsoft Windows and MAC OS.

Multi-User/Multitasking Operating Systems:

•      Allows multiple users to use programs that are simultaneously running on a single network server.

•      Here, each user is given a user session on the server.

•      UNIX, Linux are examples.

•      Maintenance can be easy.

•      Requires a powerful computer.

 

FUNCTIONS OF OPERATING SYSTEM

•      The operating system manages the computer devices (Device manager)

•      It conducts the process of booting or starting the computer (starting a computer)

•      It acts as a file manager (file management):Operating systems often provide users with the capability of managing files, viewing graphics files, uninstalling programs, scanning disks.

•      It acts as an interface between the computer and the user(providing a User interface)

•      It provides the means for proper user of the resources like monitor, memory, input and output devices,

•      It interprets the program instructions one at a time (managing programs):

•      Some operating systems support only one running program at a time others support thousands of users running multiple programs.

•      It loads the user program into the memory.

•      It gives instruction to display the results on the monitor.