Operating Systems

Operating Systems

1. Multitasking

   • By giving the processor a small time slice for each task means that all tasks appear to be executing at the same time. To the user it appears that we can multitask and have lots of programs open at once. In reality resources such as memory and the processor are being shared amongst tasks

2. User Interface

   • Command Line Interface Text based E.g. DOS, Raspbian (for Raspberry Pi) Graphical User Interface Contains Windows, Icons, Menus, Pointers Visual E.g. Windows 10, Windows 8, Android, Mac OS

3. Memory management

   • The OS allocates memory between the different programs that are open at the same time Programmers and users do not need to know where in memory data is being held – it is the purpose of the Operating System to do this

4. Drivers

   • A piece of software used to control a piece of hardware. Drivers allow a peripheral device to be connected to a computer and it be used by an Operating System. You may get drivers for graphics cards, mouse, sound card, network interface cards. Drivers are OS specific and are regularly updated by companies

5. Peripheral Management

   • Operating Systems manage the way in which hardware interacts with software A peripheral is a piece of hardware that is not directly connected to the CPU – such as a keyboard, a mouse or even a hard disk drive. An Operating System managed all of the peripheral devices that are connected to the computer – this allows them to be disabled, or drivers be updated. In windows you can access Windows Device Management

6. File Management

   • Like memory management, the Operating System must identify where files are stored for long term storage on for e.g. the hard disk drive or a solid state drive. The user does not need to know the specific track, sector and surface address – but the Operating System does in order to accurately locate a file on the hard disk drive

7. Types

   • Real Time Operating Systems (RTOS)
     • A real time operating system is an operating system that operates in real time giving a very fast response. Real time operating systems are used to get instant feedback when data has been input. An example would be an air bag system on a car. Sensors detect whether there has been a sudden deceleration and will then send the signal to a computer which will determine wither the airbag should be deployed or not.
   • Single-user Single Task Operating Systems
   • Single-user Multitasking Operating Systems
   • Multi-user Operating Systems