WELCOME TO ALL

USER INTERFACE

Introduction:

•A function of the operating system that allows individuals to access and command the computer.

•User Interface(UI), the junction between a user and a computer program.

•An interface is a set of commands or menus through which a user communicates with a program.

A Command Line Interface allows the user to interact directly with the computer system by typing in commands (instructions) into a screen which looks similar to the one below:

These commands are very specific, for example in DOS you could type in:

copy c:\item.txt   d:\

That tells the machine to copy the file 'item.txt' that resides in the root directory of drive C: into the root directory of drive D:\

Before Windows was developed, this type of user interface was what most people used to get the computer to follow instructions.

Nowadays, very few people have the knowledge to be able to use a command line interface.

An example of this type of interface is DOS (Disk Operating System).

If the user knows the correct commands then this type of interface can be much faster than any other type of interface.

This type of interface needs much less memory (RAM) in order to use it than other user interfaces.

This type of interface does not use as much CPU processing time as the others do.

A low resolution, cheaper monitor can be used with this type of user interface.

For someone who has never used a command line interface it can be very confusing.

Commands have to be typed in precisely, if there is a spelling error the command will fail.

If you miss-type an instruction, it is often necessary to start all over again.

There are a large number of commands which need to be learned - in the case of Unix, it can be hundreds.

This type of interface lets you interact with a computer or device by working your way through a series of screens or menus.

Think about your iPod or mobile phone, they both use a menu driven interface.

You are presented with a menu, you make a choice and then the next menu appears on the screen. You make another choice and so on.

Cash point machines (ATMs) are another good example of a menu driven interface.

There are no commands to learn or remember.

Step-by-step options are given so that the user doesn't have to remember anything.

Even if you don't know what to do, you can usually guess you way around the options.

Menu interfaces don't have to be visual, they can be spoken - good for telephones or for visually impaired people.

They don't need huge amounts of processing power or memory.

A poorly designed menu interface may be slow to use.

It can be irritating if there are too many menu screens to work through.

You often can't go to the exact place you want right at the start. You have to work your way through the menu screens even if you know where you want to get to.

A graphical user interface is the most common type of user interface seen today.

It is a very 'friendly' way for people to interact with the computer because it makes use of pictures, graphics and icons - hence why it is called 'graphical'.

A GUI (pronounced gooey) is also known as a WIMP interface because it makes use of:

Windows, Icons, Menus, Pointers.

All modern operating systems have at least one type of GUI. For example Microsoft Windows is a GUI, Apple Macintosh has another. Linux has a number of Graphical User Interfaces available.

This type of user interface is extremely easy to use, especially for a beginner.

You do not have to learn complicated commands.

There are usually good help facilities provided with GUIs.

They let you exchange data between different software applications .

It requires larger amount of hard disk space than other interfaces.

It needs significantly more memory (RAM) to run than other interface types.

It uses more processing power than other types of interface.

It is the job of a user interface to make a program easy to use.

A good user interface should:

-Be attractive and pleasing to the eye.

-Be easy to use.

-Ensure all screens are consistent.

-Have all options clearly shown.

-Have clear warning messages when someone makes a mistake.

-Have online help and support.

Thank You.