Real-time processing

When the computer has to react within a guaranteed time to an input, a real-time operating system (RTOS) is used. For example, the engine management system within a car uses a real-time operating system in order to react to feedback from sensors placed throughout the engine.

A real-time operating system does not necessarily have to be fast. It simply has to be quick enough to respond to inputs in a predictable way. Embedded computers often contain an RTOS as many are used to control something.

Computers operating in real time are often dedicated to the control of systems such as industrial processes, planes and space flights.

Batch processing

A batch processing system is where programs or data are collected together in a batch and processed in one go. Typically the processing of payrolls, electricity bills, invoices and daily transactions are dealt with this way.

This method of operation lends itself to jobs with similar inputs, processing and outputs where no human intervention is needed. Jobs are stored in a queue until the computer is ready to deal with them. Often batch processed jobs are done overnight.

Multi-tasking

This isn't just about running more than one application at the same time. Multi-tasking allows multiple tasks to run concurrently, taking turns using the resources of the computer.

This can mean running a couple of applications, sending a document to the printer and downloading a web page.

User interfaces

A user interface is the method by which the user and the computer exchange information and instructions. There are three main types - command-line, menu driven and graphical user interface (GUI).

Command-line interfaces

A command-line interface allows the user to interact with the computer by typing in commands. The computer displays a prompt, the user keys in the command and presses enter or return.

In the early days of personal computers, all PCs used command-line interfaces.

Features of a command-line interface

• Commands must be typed correctly and in the right order or the command will not work.

• Experienced users who know the commands can work very quickly without having to find their way around menus.

• An advantage of command driven programs is that they do not need the memory and processing power of the latest computer and will often run on lower spec machines.

• Command driven programs do not need to run in Windows.

• A command-line interface can run many programs, for example a batch file could launch half a dozen programs to do its task.

• An inexperienced user can sometimes find a command driven program difficult to use because of the number of commands that have to be learnt.

An example of a common command driven interface is MS-DOS. The MS-DOS command to display all files on c:\ would be: dir c:\

Menu driven interfaces

Simple menu

The user is offered a simple menu from which to choose an option. One menu often leads to a further menu. Part of the screen may have an instruction followed by a numbered list of options to choose from.

Full screen menu

A full screen menu takes up the entire screen.

Menu bar

A menu bar is the set of options at the top of the screen. When an option is chosen a drop-down menu may be offered.

Features of menu driven interfaces include:

• they are easy to use as the user does not have to remember sets of commands

• they are user friendly - you can often guess your way around the options

• they can be irritating if there are too many levels of menus to move around - with a command-line interface you can go to the option required immediately

Graphical user interfaces

Graphical user interface is sometimes shortened to GUI. The user chooses an option usually by pointing a mouse at an icon representing that option.

Features of GUIs include:

• They are much easier to use for beginners.

• They enable you to easily exchange information between software using cut and paste or 'drag and drop'.

• They use a lot of memory and processing power. It can be slower to use than a command-line interface if you are an expert user.

• They can be irritating to experienced users when simple tasks require a number of operations.

When discussing user interfaces, it is important to note that Windows XP, Windows Vista, Apple OSX and Ubuntu all have graphical user interfaces.

Good user interfaces

A good user interface should:

• be attractive and pleasing to the eye

• allow the user to try out different options easily

• be easy to use

• use suitable colours for key areas

• use words that are easy to understand aimed at the type of user

• have help documentation

It should also consider the needs of the users. For example, young children are likely to prefer pictures to words and people with disabilities may benefit from particular input or output devices.

Effects of e-commerce on businesses

High street stores now find themselves competing with each other for business both on the high street and online.

Selling goods online

Advantages

• Opens the market to customers nationally and internationally.

• Enables smaller companies to compete with larger companies.

• Reduces in staffing and/or high street stores thereby reducing costs.

• Provides the option to offer 24 hour shopping at minimum additional cost.

Disadvantages

• Stiffer competition - businesses once competing with the shop in the next town now find themselves competing on a global scale.

• Staff reductions - with increased competition, local companies may have to reduce their work force.

• Cost of restructuring - the move to e-commerce may not be a smooth one and will certainly require a degree of investment.

• Customer concerns - if high street stores are closed in an effort to save money, customers who prefer to shop on the high street may not be comfortable buying online so may go elsewhere.

Increased dependancy on the internet

Now, both for companies and individuals, there is pressure to have internet access to do everyday things such as submit orders or look up details in a catalogue. There are initiatives to make as many services available on the internet as possible, including e-government, where government departments such as the Inland Revenue can be dealt with using secure websites.

Electronic money and electronic commerce

Most companies pay their employees via bank transfer, from the companies account to the employees'. It's now rare to be paid in cash.

Goods and services are usually paid for with electronic methods of payment, for example:

• direct debit

• standing order

• debit cards (Switch/Delta)

• smart cards

• online bank transfers

Electronic Commerce

Electronic Commerce or e-commerce is the selling and buying of goods or services over the internet.

E-commerce has both advantages and disadvantages for businesses and customers.

Advantages for businesses

• Increased customer base – with a website, a local store can have an international customer base.

• Cost effective – save on staffing a physical shop (or shops) and the associated costs, eg rent, electricity, gas, water etc.

• Services - for example, accountancy, lend themselves to being advertised online. Specifics on what's offered can be listed on the website, decreasing the need for real world consultation.

Disadvantages for businesses

• Increased competition - competition once limited to other local shops is now on an international scale.

• Newcomers - consumers may be reluctant to buy from a company they haven't heard of.

• Slow adoption - companies whose competitors already have an online presence may find it hard to gain market share.

Advantages for customers

• Increased convenience - customers can find what they're looking for without leaving their home.

• Greater choice - customers are no longer limited to shops nearby and can even buy from abroad.

• Cost effective - competition on an often international scale means prices are cheaper/more competitive.

• Product details - greater wealth of information available online than what a member of staff is able to provide in-store.

• Customer reviews - many sites allow customers to review products or services they’ve purchased, increasing buyer confidence.

Disadvantages for customers

• No human interaction - some people prefer to buy their goods or services in person.

• Returning goods - can be inconvenient (arranging postage) and expensive (if it is a large/heavy item).

• Fraud - a website may take your money, but have no intention of delivering the goods.

• Stock issues - the product may be out of stock, or if ordered and later found to be out of stock, a substitute product may be sent instead.