2. What is an Operating System?
The operating system (OS) is the program which starts up
when you turn on your computer and runs underneath all
other programs - without it nothing would happen at all.
In simple terms, an operating system is a manager. It
manages all the available resources on a computer, from
the CPU, to memory, to hard disk accesses.
3. Operating System
A program or a software that governs the functioning of
other programs
Interface between User and the Hardware
Allocates resources for tasks
Allocates tasks to programs
Manages space and time
Controls the devices
4. Tasks the operating system must perform:
Control Hardware - The operating system controls all
the parts of the computer and attempts to get
everything working together.
Run Applications - Another job the OS does is run
application software. This would include word
processors, web browsers, games, etc...
Manage Data and Files - The OS makes it easy for you
to organize your computer. Through the OS you are
able to do a number of things to data, including copy,
move, delete, and rename it. This makes it much
easier to find and organize what you have.
5. Types of Operating System
Tasks
Uni tasking
Multi tasking
Users
Single User
Multi User
Processing
Uni processing
Multi processing
Timesharing
6. Real-time operating systems
A real-time operating system (RTOS) is an operating system
intended for applications with fixed deadlines (real-time
computing). Such applications include some small
embedded systems, automobile engine controllers,
industrial robots, spacecraft, industrial control, and some
large-scale computing systems.
An early example of a large-scale real-time operating
system was Transaction Processing Facility developed by
American Airlines and IBM for the Sabre Airline Reservations
System.
7. Why are Operating Systems Important?
Important to understand and know how to correctly use
when writing user applications.
Large and complex systems that have a high economic
impact and result in interesting problems of management.
Few actually involved in OS design and implementation
but nevertheless many general techniques to be learned
and applied.
Combines concepts from many other areas of Computer
Science: Architecture, Languages,
Data Structures, Algorithms.
8. Examples of OS
Microsoft Windows
Mainframe
DOS
OS/2
Linux
Mac OS
Amiga OS
Android
