introduction Flashcards
Operating system
An operating system is a program that acts as an interface between the user and the computer hardware and controls the execution of all kinds of programs
Function of Operating system
- Memory Management
- Processor Management
- Device Management
- File Management
- Security
- Control over system performance
- Job accounting
- Error detecting aids
- Coordination between other software and users
Types of Operating System
Batch operating system
Time-sharing operating systems
Distributed operating System
Network operating System
Real Time operating System
Batch operating system
The users of a batch operating system do not interact with the computer directly The programmers leave their programs with the operator and the operator then sorts the programs with similar requirements into batches.
problems with Batch Systems
- Lack of interaction between the user and the job.
- CPU is often idle, because the speed of the mechanical I/O devices is slower than the CPU.
- Difficult to provide the desired priority
Time-sharing operating systems or multi-user
Time-sharing is a technique which enables many people, located at various terminals, to use a particular computer system at the same time
Advantages of Timesharing operating systems
- Provides the advantage of quick response.
- Avoids duplication of software.
- Reduces CPU idle time
Disadvantages of Time-sharing operating systems
- Problem of reliability.
- Question of security and integrity of user programs and data.
- Problem of data communication
Distributed operating System
Distributed systems use multiple central processors to serve multiple real-time applications and multiple users
The advantages of distributed systems
User at one site may be able to use the resources available at another.
* Speedup the exchange of data with one another via electronic mail.
* If one site fails the remaining sites can potentially continue operating.
* Better service to the customers.
* Reduction of the load on the host computer.
* Reduction of delays in data processing
Network operating System
A Network Operating System runs on a server and provides the server the capability to manage data, users, groups, security, applications, and other networking functions
The advantages of network operating systems
- Centralized servers are highly stable.
- Security is server managed.
- Upgrades to new technologies and hardware can be easily integrated into the system.
- Remote access to servers is possible from different locations and types of systems.
disadvantages of network operating systems
- High cost of buying and running a server.
- Dependency on a central location for most operations.
- Regular maintenance and updates are required.
Real Time operating System
A real-time system is defined as a data processing system in which the time interval required to process and respond to inputs is so small that it controls the environment.
Soft real-time systems
Soft real-time systems are less restrictive. A critical real-time task gets priority over other tasks and retains the priority until it completes
