Operating Systems

Operating Systems

1. Providing an interface

   • Graphical User Interface(GUI)
     • Used by most PC and phone operating systems
     • Graphical representations of the computer’s functions are shown to the user and controlled by touchscreen or a mouse and keyboard
     • Programs often run in windows and several can be shown at the same time
   • Command Line Interface(CLI)
     • A CLI is a text-based interface
     • The user types commands, and the result is shown as text
     • Nearly every operating system provides a CLI
     • These are harder to use, but are very lightweight and robust – they use few system resources and are very unlikely to crash or break

2. File Management

   • Provides them an interface that allow them to:
     • Copy files
     • Move files
     • Delete files
     • Sort files
     • Search for files

3. System Settings

   • Operating systems enable the user to easily alter system settings
   • It can enable or disable hardware
   • It can change the volume
   • It can adjust screen resolution
   • It can configure secondary storage

4. Multitasking

   • Multitasking is allowing multiple processes appear to run simultaneously
   • OS simulates it by alternating which processes get CPU time
   • A GUI will generally allow different processes to run in separate windows, and be displayed side by side

5. Error messages and support

   • When something goes wrong in a program, the user needs to be informed
   • However, the programmer may not know how the program is being used (GUI, CLI or remotely on an embedded system).
   • The error is passed to the operating system, which then displays it in the most suitable way
   • This produces consistent error handling regardless of what application is being used

6. Customisation

   • The ability to customise the interface is a feature of most operating systems
   • Some provide options to change the colour scheme and desktop background
   • Others allow a completely different desktop environment to be installed

7. Task Management

   • Operating systems manage processes and allow multitasking
   • The also provide the user with the option to quit programs, or kill unresponsive processes
   • Some also allow the user to prioritise certain processes, allowing certain apps to use the full processor speed