The purpose of operating systems
- 1. THE PURPOSE OF OPERATING SYSTEMS
- 2. W H AT I S A O P E R AT I N G S Y S T E M The operating system is stored in the HDD (Hard Disk Drive), it is the most important type of essential software system in the computer. Without the OS peoples computers would not be able to run as many applications as somebody with OS. You would normally be able to find Operating Systems in things such as personal computers, SAT NAVs, network servers, mobile phones, Games consoles, cars etc. . . .
- 3. THE MAIN FUNCTION OF A O P E R AT I N G S Y S T E M Processor management Memory management Device management Storage management User interface
- 4. PROCESSOR MANAGEMENT The OS controls the jobs sent to the CPU, as the processor can only manage one job at a time, however can process 7000 jobs a second, which makes it look like it can multi-task. The operating system also controls the buffer. The buffer can hold multiple jobs that have been sent to the processor at once, the buffer then records all the jobs sent by the input device and gives it to the processor when it has finished its previous jobs, essentially slowing down the job rate.
- 5. MEMORY MANAGEMENT The virtual memory in the computer allows you to run more applications than it has RAM for. The reason for the virtual memory is to make the address space bigger, e.g.: The virtual memory may have twice as much space as the computer memory.
- 6. DEVICE MANAGEMENT This is the part of the computer that controls devices that are connected to the computer, it makes sure that there is a driver for the devices, to keep the computer running something . The OS controls devices such as mouse and keyboard. A device driver is a section of software that allows the OS to communicate with hardware devices that are attached to the system.
- 7. STORAGE MANAGEMENT There are 2 types of storage on a computer: Main storage- provides storage that can be accessed directly by the CPU. Secondary storage- there are three main functions of the secondary system : o Managing the free space on the secondary storage device. o Allocation of storage space when new files have to be written. o Scheduling the requests for memory access. A file system such as FAT allows you to organize pieces of data that are expected to be kept when the program has been taken off or deleted, it does this by updating data.
- 8. USER INTERFACE User interface is in the space where humans and the computers interact, things that allow you to interact with the computer are the monitor, mouse and keyboard, you make physical contact with these things which creates user interface. GUI (graphical user interface) allows you to open and use files with out having to type in lots of code.