Resources under operating systems control
A computer is composed of a set of software-controlled resources that enable movement,storage and processing of data and information.The resources or devices under the operating system control include: the processor,the main memory(RAM),input and output device and parts,secondary storage devices and communication devices.
The processor
The processor is a scarce resource.It executes tasks called processes.At any one time several tasks may require processing hence creating competition.The operating system arranges the tasks according to priority and has the ability to stop a particular task to allow the processor to service another one.
Main memory(RAM)
At any one given time so many tasks may require the memory so that they can be accessed and processed by the computer.However,because memory is also a scarce resource,the operating system determines which task will remain in memory awaiting for execution and which one will be sent back to secondary storage to wait.
Because the operating system is large and very important,it is usually installed on the hard disk but must be loaded to RAM during the booting process.Not all the operating system can fit in RAM so a small special part that contains the most necessary commands and procedures called the kernel is the one that is loaded.
Input/output devices and ports
In most cases,the operating system controls all data input and information output tasks.Because most input/output devices are slower than the processor,the operating system has to control the flow of data from the time of input to the time the user receives it as information.It ensures that the right data reaches the processor at the right time.The operating system also defines the various input/output ports found on the computer e.g. printer port.
Secondary storage devices
The operating system manages the storage and retrieval of data on secondary storage devices.It also utilizes the free space on hard disks to enhance the performance of the computer by temporarily holding tasks on it that were in RAM ready for processing but have to wait for sometime.
Communication devices and ports
Communication in this case refers to how the various devices and programs in and out of the computer system send and receive messages from one another and from the processor. The operating system controls the overall communication process between various tasks and computers.External communication can be achieved by connecting an external device to a communication port using a communication medium like cables or even wireless communication.