Operating Systems

Operating Systems

1. Peripheral Management

   • Any computer hardware component not part of CPU
   • Operating System manages these
   • Operating System will find/ask users to install suitable drivers and these allow Operating System to communicate with the device

2. Memory Management

   • When program is running it must be in computer's main memory (RAM). The main memory has a finite size
   • Operating System must manage the memory and where the programs go. It tracks where they are at any time to make efficient use of space in memory and to make sure that nothing gets overwritten by something else.
   • As a program is finished it can be removed from memory and as new ones are run, they will be loaded into the memory.

3. Security

   • Operating Systems usually allow the authentication of users (can be set up to check who the users really are).
   • Normally involves user ids and password(s).
   • Operating Systems also handle file privileges, these are right assigned to users and groups. This controls who can read/write and execute files.

4. Multi-tasking

   • Most systems commonly have several programs loaded into memory at the same time.
   • The operating system will also be running lots of background tasks just to manage the computer itself. A processor can only execute one instruction at a time (assuming it only has one core).
   • The operating system has to mange all the programs running to make sure each one gets enough processor time.

5. User Interface

   • Operating systems need to provide a means of communicating with them. This means making it possible for the user to issue commands.
   • The user interface is the way in which users interact with computer hardware. This can be either Graphical (GUI) or Command Line.