USER INTERFACES AND PROCESSING MODES

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)

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)

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

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

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.

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.

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

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.