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TOPIC: OPERATING SYSTEM
CONTENT
- Definition of operating system (OS)
- Examples of Operating system
SUBTOPIC 1: DEFINITION OF AN OPERATING SYSTEM
DEFINITION OF AN OPERATING SYSTEM
- Operating system: This is a set of program that coordinates all the activities among computer hardware devices. It also contains instructions that allow users to run application software. When a user starts a computer, portions of the operating system (OS) load into memory from the computer’s hard disk. It remains in memory while the computer is on. The operating system provides a means for users to communicate with other software. It is the operating system that makes the computer understands the user’s instructions and command. It is the life-wire of a computer system. It does the loading and schedule of all activities going on in a computer system.
For users to be able to interact with the computer machine, the operating system provides the user with what is called user interface (UI)
What is user interface (UI)?     This is the space through where interactions between humans and machine occur. The goal of UI is to allow effective operation of the computer machine.
Types of User Interface
- Command based interface
- Graphical User Interface (GUI): with graphical user interface, you interact with the software using text, graphics, and visual images such as icons. An icon is a small image that represents a program, an instruction, or some other object on the computer screen.
EVALUATION
- Define the term Operating System
- Mention what establishes a relationship between the user and the computer machine
- A pictorial representation on the computer screen is called what?
- Mention the two types of user interfaces
Sub-topic 2:
TYPES OF OPERATING SYSTEMS
There are different types of operating system as specified by their operational performance. The most commonly used operating systems is:
- Single user Operating System
- Multi User Operating System
- Distributed Operating System
- Multiprocessing Operating System
Single user operating system
Types of single user OS:
- Single User/Single tasking OS: allows only a single task 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 Palm OS for Palm handheld computers.
- Single User/Multitasking OS: allow several programs to run at the same time by a single user. Example is Window 95, Windows NT, Workstation and Windows 2000 professional.
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