OPERATING SYSTEM - FUNCTIONS

• Handles input and output
• Selects and controls the operation of the hardware devices such as keyboards, mice, scanners, printers etc.
• Recognises hardware device such as pen drive, camera etc. when they are attached to the computer and automatically loads the software (device driver) it needs to control the device.
• Supervises the running of other programs
• Provides a way for application programs like word processors, spreadsheets etc. to work with the hardware.
• Handles the storage of data
• Keeps track of all the files and folders on the disk.
• Maximises the use of computer memory
• Decides where in memory the program instructions are placed.
• Ensures the parts of the program needed frequently are put in fastest part of the memory.
• Handles interrupts and decides what action to take
• Alerts the user when errors like printer cannot print because of paper jam or it has run out of paper.

 

OPERATING SYSTEM - INTERFACE
Interface is used by the Operating System for interacting with the user.
Commonly used interfaces are:
Command Line Interface (CLI)
Graphical User Interface (GUI)

 

COMMAND LINE INTERFACE (CLI)
Advantages:

• For an experienced user typing in commands using CLI is quicker than moving the mouse or clicking.
• Uses less disk space than GUI when stored
• Requires lesser memory (RAM) when being used.
• Does not need powerful hardware like processor, graphics card to run a CLI.

Disadvantages:

• User needs to remember commands and their syntax.
• Commands must be issued in a specific order otherwise commands will be rejected.
• Difficult to operate for a beginner.

 

GRAPHICAL USER INTERFACE (GUI)
Advantages:

• User friendly - very easy to use for the novice user
• Has features such as Windows, Icons, Menus and Pointers (WIMP)
• No need to remember commands and its syntax.
• Can be operated using point and click method. 

 

Disadvantages:

• Takes more storage space on the disk.
• Requires more memory (RAM) when being used.
• Powerful hardware like processor, graphics card are needed to run latest version of a GUI.
• Experienced user might find that typing in commands is quicker than moving the mouse or clicking.

 

Expected Questions:

Q: Graphical User Interfaces are very popular interfaces that are used with computers, mobile phones and other portable devices.

(a) Give three features of a graphical user interface [3]

Q: All computers need an Operating system.
(a) Explain what an operating system is. [2]
(b) List three functions of an operating system. [3]
Q: Name any one device other than computer and mobile that has GUI.
Q: List any two benefits of having this interface. [3]