An Operating system (OS) is a set of programs that is used to manage the basic hardware resources of a computer.
This is the mam program that controls the execution of user applications, and enables the user to access the hardware and software resources of the computer.
When the computer is switched on, the OS programs run and check to ensure that all parts of the computer are functioning properly.
Operating system's platform
In a data processing environment, the user sees a computer as a group of application programs that enable him/her to accomplish specific tasks.
However, application programs do not use the hardware devices directly. They send messages through the operating system which has the capability to give instructions to the hardware to perform a particular task.
The user communicates his/her intentions to the OS through the use of a special instruction set known as Commands.
The OS is a layer of software on top of the bare hardware, and is used to manage all parts of computer hardware and also act as an interface between the user and the computer.
The OS monitors and controls computer operations so that the user can do useful work on the computer, and it also enables Application programs use the hardware m a proper, orderly and efficient way.
NB. The programs that make up the Operating system are too large to fit in main memory at one time. These programs are usually installed on a direct access backing storage device, such as the hard disk.
When the Supervisor needs a particular program, it is read from the disk and loaded into the RAM memory, where it can be executed.
Reasons why an Operating system is needed in a computer
i). Modern computer systems are so complex and fast such that they need internal control.
This is the mam program that controls the execution of user applications, and enables the user to access the hardware and software resources of the computer.
When the computer is switched on, the OS programs run and check to ensure that all parts of the computer are functioning properly.
Operating system's platform
In a data processing environment, the user sees a computer as a group of application programs that enable him/her to accomplish specific tasks.
However, application programs do not use the hardware devices directly. They send messages through the operating system which has the capability to give instructions to the hardware to perform a particular task.
The user communicates his/her intentions to the OS through the use of a special instruction set known as Commands.
The OS is a layer of software on top of the bare hardware, and is used to manage all parts of computer hardware and also act as an interface between the user and the computer.
The OS monitors and controls computer operations so that the user can do useful work on the computer, and it also enables Application programs use the hardware m a proper, orderly and efficient way.
NB. The programs that make up the Operating system are too large to fit in main memory at one time. These programs are usually installed on a direct access backing storage device, such as the hard disk.
When the Supervisor needs a particular program, it is read from the disk and loaded into the RAM memory, where it can be executed.
Reasons why an Operating system is needed in a computer
i). Modern computer systems are so complex and fast such that they need internal control.
ii). To ensure that the full system software facilities are readily available.
iii). Due to the complexity of systems, jobs need to be controlled in what they are allowed to do for security.
iv). To increase the throughput, i.e., to increase the amount of data that can be processed through the system in a given period of time.
v). Improve communication between the user and the computer.
iii). Due to the complexity of systems, jobs need to be controlled in what they are allowed to do for security.
iv). To increase the throughput, i.e., to increase the amount of data that can be processed through the system in a given period of time.
v). Improve communication between the user and the computer.
vi). To make complex tasks very simple for the user to carry out.
vii). It helps the computer to correct any problem that might occur. When an error occurs that can cause the computer to stop functioning, a diagnostic message is displayed. The meaning of the message is then checked in the computer operations manual.
viii). Reduces job setup time. When one job is running, other programs can be read onto the job queue. The Input/Output devices can also be made ready without delay.
ix). Most computers allow many programs to be run and also many users to use the system at the same time.
Devices under the control of an Operating System.
A computer is composed of a set of software-controlled resources that enable movement, storage and processing of data and information.
As a resource manager, the OS manages the following basic resources devices;
1. Processor.
2. Main memory (RAM).
3. Secondary storage devices.
4. Input/Output devices and their Ports.
5. Communication devices and their Ports.
6. Files.
vii). It helps the computer to correct any problem that might occur. When an error occurs that can cause the computer to stop functioning, a diagnostic message is displayed. The meaning of the message is then checked in the computer operations manual.
viii). Reduces job setup time. When one job is running, other programs can be read onto the job queue. The Input/Output devices can also be made ready without delay.
ix). Most computers allow many programs to be run and also many users to use the system at the same time.
Devices under the control of an Operating System.
A computer is composed of a set of software-controlled resources that enable movement, storage and processing of data and information.
As a resource manager, the OS manages the following basic resources devices;
1. Processor.
2. Main memory (RAM).
3. Secondary storage devices.
4. Input/Output devices and their Ports.
5. Communication devices and their Ports.
6. Files.
