1. USER INTERFACES AND PROCESSING MODES

2. User- interfaces
This provides the link between the computer and the User.
There are three main types:
Command Line(Driven)
Menu-Driven
Graphical User Interface(GUI)

3. Command-driven This requires you to type in commands. Eg. MS-DOS
Advantage
Powerful way to get task done
Disadvantage
User can easily forget commands
Commands follow a syntax(grammar rule)

4. Menu driven This provides a list of options from which you can choose.
Advantage
More user friendly than the command-driven interface
Easy to Learn

5. Graphical user interface
The user can use a mouse to select the various items and execute programs.
The GUI consists of Windows, Icons,Menus and Pointers (WIMP)
Window: Part of the screen that holds a document or message.
Icon: a picture of an object on the screen
Menus: Pull-down, Pop-up, (Ribbons)
Pointers: Indicates the position of the mouse on the screen

6. Processing Modes(PG 45)
These are modes describing how data is processed.
Batch Processing
This occus when the computers processes all the data at once over a long period of time.
Examples: Utility bills(Water and Electricity), payroll systems (list another example).
Advantages: Less expensive than real-time. The user doesn’t have to be present. Data is loaded in one operation.
Disadvantages: It is a long process. Expensive servers are used.

7. Processing Modes (PG 45)
On-Line Processing
A computer is online when it is connected to a network. Data is processed shortly after it was entered into the system.
Examples: Printer, ATMs
Advantage: Faster than Batch processing.
Disadvantage: Not updated automatically, like Real time processing.

8. Processing Modes (pg 45) Real-time Processing
Processing occurs instantaneously.
Examples: Anti-missile defence system, aeroplane landing control systems, electronic transfer system
Advantages: Information is always up-to- date; Information is always available
Disadvantages: Computer must be on-line;
Not suitable for large amount of input data

9. Processing modes Time Sharing
This gives many users access to the same data apparently at the same time.
Example
Travel agents using the same airline database to book flights for clients.