The 1960’s definition of an operating system is “the software that controls the hardware”. However, today, due to microcode we need a better definition. So, we saw an operating system as the programs that make the hardware usable.
“It is the set of programs that controls a computer.” and therefore, It is collection of system software used to manage the overall operation of a computer system.
“It provides a set of services to programs and the user interacts with the operating system indirectly through the programs”. OR “An operating system is the software that takes the raw capabilities of the hardware and build a more practical platform for the execution of programs.”
Hence, in conclusion:
- Any mechanism has an operating system.
- It converts real machine into the virtual machine.
- A better operating system converts real machine completely into the virtual machine.
- If we do not have a control of operating system, then no application will run and a computer becomes a useless thing.
As a result, op-system is very important.
Operating system and computer
- Operating system is designed to support fully the activities of a computer and therefore, it is like the operator of whole computer.
- The prime objective of an operating system is to improve the efficiency and performance of computer system.
- OP-System is like a manager of a company, and hence, OP-system is responsible for the smooth and efficient operation of the entire computer system.
- An OP-System makes the computer user friendly, and thus it makes the computer easier for people to use.
An OP-System performs these two main functions:
- Resource Sharing
- Provision of a virtual machine
An op-system share the resources of the computer among the users, but the aim of the op-system is to increase the availability of the computer to its users. And at the same time it maximize the utilization of resources such as: The central processor, memory and input/output devices.
Many microcomputers are dedicated to a single function and never shared all data. However, large computers are still expensive enough to warrant considerable effort in sharing their resources.
Provision of a virtual Machine
The second major function of op-system is to transform a raw piece of hardware into a machine,and therefore it is more easy to use by a user.
In further discussion, an op-system must perform the following functions:
- Job sequence
- Job control language interpretation
- Error handling
- I/O handling
- Interrupt handling
- Resource control
- Provision of good interface to operator
- Accounting of computing resources