3.1.2 Software and hardware components of an information system

Graphics Tablet

Using a graphics tablet, a designer can produce much more accurate drawings on the screen than they could with a mouse or other pointing device. When combined with an art application such as Corel Painter or Photoshop, a talented artist can produce incredible illustrations and images with it.

5 advantages of standards?

-More choice from a variety of manufacturers. -Lower prices and better technical development. -Not locked into one manufacturer. -Can be purchased from many retail outlets. -Easy to find alternative equipment.

4 disadvantages of using a manufacturer who doesn't follow standards?

-Once you have purchased your equipment you are locked into that manufacturer. -You cannot sensibly compare equipment as they use different standards. -There is a lack of price competition which can result in higher prices. -There may be less encouragement for technical development due to fewer competitors.

Braille Keyboard/ Printer (hardware)

A Braille keyboard is a specialist input device that allows the user to type and enter text or instructions for the computer in Braille. A braille display is a piece of equipment that connects to the computer. It reads the screen text and presents it to the user via a refreshable Braille display. A Braille printer operates by embossing raised braille dots onto braille paper. Pins are pressed into one side of the paper in order to create raised dots on the other side of the paper.

DVD

A DVD is similar to a CD in that it is an optical device and that a laser is used to store the data and read the data, stored 4.6Gb on a side. Large storage capacity, sound and picture quality is excellent, relatively cheap, DVD players can read CDs. However, DVDs do not work in CD drives, no single standard of DVD, can be easily damaged by breaking or scratching.

Utility Programs

A Utility program is designed to do one or perhaps two tasks very well and nothing else, e.g. you may want to compress a file to let you save it on to a flash drive. For this task you would choose to use a file compression utility program. Quite often, a Utility program is built right in to the operating system. For example Windows has a built in 'Zip' compression utility you can use to compress a file or folder. Common tasks include: File repair, disk monitoring, printing jobs, backing up data, anti-Virus.

Barcode Reader

A barcode reader is an automatic input device which is used to scan or 'read' the barcode by using a visible red light. The reflected light is translated into digital data that is interpreted by the computer to identify the product and price from the database. The main advantage of using a barcode system is that any price change only needs to be made to the database and not every single product package.

Concept Keyboard?

A concept keyboard is a flat board that contains a grid of buttons. Each button can be programmed to do whatever you want. An overlay sheet with pictures or symbols is placed on the grid so that the user can tell what pressing on different areas will do. Much faster for making non-text selections such as menu choices on the till of a fast-food outlet. The keyboard is waterproof. Poor for text or numeric input - although some keyboards do include a numeric keypad so the operator can enter the amount sold. Limited options.

Foot Mouse (hardware)

A foot mouse / control can be used by a person who has limited or no use of their hands or arms. The foot mouse can be used to navigate through software programs and select things in much the same way as a conventional mouse. Most foot mice consist of two segments. One segement will be used to control the cursor, the second segment is used to click the mouse or to select shortcuts. Most foot mice include straps that help to hold the device in place on the foot during use. A long cable runs from the mouse and plugs into the computer via a USB port.

Forms interface

A form interface which will allow you to interact with the system software might offer choices such as selecting your screen resolution, default language, keyboard style etc. A form interface can also be used to enter data into a system. Easy to program, easy for user to see available options, fast to enter data/ make choices, no training needed, don't need a lot of processing power or memory. However, only limited options presented, visually impaired will not be able to see/ read the options very well, not good for highly complex applications resulting in pages of options to be decided.

GUI or WIMP

A graphical user interface is the most common type of user interface seen today. Made up of Windows - a rectangular area on the screen where applications run Icons - a picture or symbol which is used to represent a software application Menus - a list of options Pointers - a symbol such as an arrow which moves around the screen as you move your mouse. Very easy to use and explore around, no commands learned, benefits of WYSIWYG, good help facilities. However, takes up more space on the hard disk, needs more memory (RAM) to run, more processing power needed, very slow for command line users.

Microphone (hardware)

A microphone can be useful for people who find it difficult to use a keyboard or mouse. The person speaks their input clearly and specialist software is then used to convert the speech or commands into text or other actions.

Monitor

A monitor (or screen) is the most commonly used output device. They come in many different shapes, sizes and forms. The picture on a monitor is made up of thousands of tiny coloured dots called pixels. The quality and detail of the picture depends on the number of pixels that the monitor can display. The higher the number of pixels, the better quality the output.

Mouse

A mouse is also called a 'pointing device' because it enables you to control what happens on the screen by moving the mouse on your desk and pointing, clicking and selecting items on the screen. -Most computer users are familiar with them and require little training. -Ideal for use with desktop computers. -They need a flat space close to the computer. -Overuse can lead to RSI.

Peripheral

A peripheral is any hardware device which connects to the computer and is controlled by the Central Processing Unit (CPU) -with the exception of memory, e.g. monitor, scanner, speakers, graphics tablet.

Output Device

A piece of hardware that is used to display or output data which has been processed or has been stored on the computer.

Input Device

A piece of hardware that is used to enter data into a computer. There are many different kinds of input devices. They are split into two categories - manual input devices and automatic input devices.

Plotter

A plotter differs from a printer in that it draws images using a pen that can be lowered, raised and moved across the paper to form continuous lines. The electronically controlled pen is moved around the paper by computer controlled motors. Drawings are of a very high quality, larger sizes of paper can be used. However, they are slow due to each line being drawn separately, more expensive than printers, text is not high quality.

Application Software

A software application carries out tasks that the user is interested in doing such as writing a letter, creating graphs, sending an email or downloading a webpage. Software applications work through the operating system to gain access to the hardware. Application software can be classified under three main categories: general purpose software, specialist software, bespoke software.

Touch Screen

A touch screen is the only device which works as both an input and an output device. Easy to use - intuitive, don't need much training, No extra peripherals such as a mouse are needed. Not very accurate - selecting detailed objects can be difficult with fingers, Tiring to use for long periods, Not robust - can soon become faulty if misused.

Command Line Interface

Allows the user to interact directly with the computer system by typing in commands (instructions) into a screen. You cannot just type in any kind of instruction of course, because the computer will only react to a definite set of words. The main disadvantage of a command line interface is that the person must have detailed knowledge of the command that can be used as it can be very confusing and commands have to be very precise as if you make a mistake you will probably have to start over. However this method is much faster if you know what you're doing, and it takes up less CPU processing power and less RAM (memory), and a lower quality monitor can be used.

OCR

An OCR system consists of a normal scanner and some special software. The scanner is used to scan text on a document or piece of paper into the computer. The OCR software then examines the page and changes the letters into a form that can be edited or processed by a normal word processing package. Cheap and fast, but not 100% accurate due to handwriting being difficult to read.

Screen Magnifier (hardware)

Another option that can be used to help people with visual impairment is a hardware screen magnifier. The one shown above can magnify the video feed from a standard display and can also magnify paper documents placed below the video camera input.

Blue Rays

Blu-ray disk can store even more data than a DVD. A single layer disk can hold 25GB whilst a double layer disk can store up to 50GB. They look quite similar to a CD or DVD as they are the same size (form factor), however, only a dedicated Blu-ray player can play them. They store much more data than a DVD disk, able to store a full length high definition film. However, you need a dedicated Blu-ray player to play the disks, and loading a film can take minutes as so much data needs to be read.

CD

CD-ROM - CD Read Only Memory, e.g. music CD. CD-WORM - CD Write Once Read Many. This means that you are able to save whatever you want to this disk one time. CD-RW - CD ReWritable. This means that you can save data to your disk over and over again. Compact disks are known as optical storage devices. Data is burned onto the surface of the disk using a laser beam in the CD drive. A laser beam is also used to read the data stored on the disk, can hold about 650mb. Small, portable, cheap to produce, most computers can read CDs, fairly fast to access the data. However can scratch/ snap easily, slower to access than hard disk, can't store as much as DVD.

Biometric Devices

Finger print and retinal identification are being used in many places now and even facial recognition systems are starting to be introduced. Specialised scanning devices are needed to capture the biometric data which is then passed onto the computer for processing and identification. A common use of biometric data is in the modern UK passport.

OS Options

For poor eyesight - by making text larger and optimising the clarity of the text or for complete blindness allow for using the computer without a display. You can choose to use text or visual warnings instead of the usual alarm sounds. You can select the sensitivity of the mouse or use a different pointing device. For typing, the behaviour of the keyboard can be adjusted.

General Purpose Application Software

General purpose application, sometimes known as 'off-the-shelf' is the sort of software that you use at home and school. But it does try to be' all things to all people' and so there will be a vast number of features that you may never use e.g. statistical functions, mail merge. This makes the storage size of these applications fairly large. It is relatively cheap, easily available from most computer shops, will have been thoroughly tested, lots of user support i.e. books, user guides, online help. Examples of use: Desktop publishing application - creating leaflets, posters, business cards, Presentation software - creating presentations to show to customers or staff, Graphics application - manipulating images that can be used at home, school or a business.

Hardware

Hardware is any part of the computer that you can physically touch, pick up, hold, move around the room , e.g. monitor, mouse, hard disk, motherboard etc.

Keyboard

It is made up of buttons called 'keys'. The keys are arranged into sections: Alphabet keys, Function or F keys, Numeric keys, Arrow keys, Command keys (insert, delete). Most keyboards are called 'QWERTY' keyboards. This name comes from the first six letters on the top row of the alphabet keys.

LED's

Lights such as LEDs (Light Emitting Diodes) can be connected to a computer or within equipment and respond to electrical signals which tell them to switch on and off. Very cost effective way of indicating status, provide a warning for users with hearing loss who cannot hear error beeps, come in a large range of different colours. However, light may break or wear out, may be a loose connection which means the light doesn't switch on, and they can only indicate simple status (on/off).

OMR

Lottery forms are scanned by a special piece of equipment called an 'Optical Mark Reader' (OMR). they detect the presence of your pencil mark by reflecting light onto it. Less light is reflected where a mark has been made. Fast at inputting lots of data quickly, very accurate but not suitable for text input, may not be able to read answers not dark enough.

Magnetic Tape

Magnetic tape uses 'serial access' to find a piece of data. To find a specific piece of data, you have to start at the beginning of the tape and continue fast forwarding until you get to the piece of data that you need. This makes it fairly slow to find and retrieve data so it would not be much use to store data that you needed to get hold of quickly. Relatively cheap per megabyte of storage, can store large amounts of data - over 100 Gb, can be set up to do the back up overnight, robotic archive and backup systems can swap tapes in and out automatically. However, need a special piece of equipment to record and read the data on the tape, tape can easily break.

Zoom Tool (software)

Many software applications have the facility to allow you to zoom in closer on the work being displayed on the screen. Typically, you can choose to zoom in at different magnifications from 100% to around 500%. This can be useful for people with poor eyesight. There are also specific commercial applications that are designed to help with visual impairment.

Speaker

Most computers are fitted with a small internal speakers that beep but can also be fitted with a sound card (or chip) which will enable sound to be output through external speakers, producing a much higher quality sound than the internal speaker. Everyone in the room can hear the sound, creates an atmosphere or ambience for presentations, help blind people to use the computer because text can be converted into sound. However, output from speakers can disturb others who are trying to work and high quality external speakers can be expensive.

Menu Driven interface

Most of the software that you use have menu interfaces. 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, e.g. cashpoint machines (ATMs). Extremely easy to use, no commands to remember, don't need huge amounts of processing power/ memory, can be spoken so good for blind people. However, irritating if there are too many menus, cannot go to the desired option right away, if poorly designed it can be hard to read, takes up a lot of the screen so you have to flick back and forth to applications.

Standards Over Time

No standards at the beginning of the PC industry in the 1980s. However IBM created the PC standards so that parts can be made from different companies but will work together as they have the same standards. Some companies such as Apple keep their own OS and peripherals just to their system so standards and compatibility are maintained, but this means less flexibility.

MICR

Numbers on cheques are written in a special ink which contains iron particles. This ink is magnetised and commonly called 'magnetic ink'. It can be read by a special machine called a Magnetic Ink Character reader (MICR).

System software

Operating System, utility programs and drivers.

User Interface

People need a way of interacting with machines such as computers, PDAs, mobile phones, ATM machines etc. A User Interface is the software that enables you to provide instructions and to control the device.

RAM

RAM, or 'temporary memory' is known as 'volatile memory'. As well as storing the data you are working on, RAM also stores the modules that are needed to make your applications work. RAM is also needed so that you can have multiple windows open and so that you can switch between them. However, if you have a lot of windows, documents and different applications running, you might find that your system starts to slow down. This is because your RAM is full up and it is having to decide what it needs to keep stored in memory at any given time and what it can release.

ROM

ROM is a special kind of memory which stores the instructions which the computer uses when it 'boots up' - the BIOS (Basic Input Output System). It allows it to check the type of hard disk installed, the amount of RAM installed (see next page), the type of CPU being used etc. Because the data is 'read only', it can be read but not changed by the user. The data is not erased when the computer is switched off - the data is stored permanently. This type of memory is called 'non volatile memory'

Scanner

Scanners can be used to convert images or text on paper into a digital format that can be used by the computer. Items that are scanned are usually stored in an image format. However, special software - Optical Character Recognition - can be used to convert text on the paper into text which can be edited with a word processor.

Software

Software are the applications and programming instructions needed to make the computer hardware do useful work, e.g. OS, utilities, word processors, databases.

Bespoke Software

Software system designed and developed specifically for a business- 'tailor-made' or 'bespoke' software. The company will get the exact software/system that they need, the software will work exactly how they want it to work, the software will only have the features that they specifically need in their business. However, it takes a long time to develop such a system, it costs a great deal of money, the company may need to employ a team of people such as programmers and testers, there will be little in the way of user support.

Speakers (hardware)

Speakers can be useful for visually impaired people in terms of text-to-speech systems. The text-to-speech system takes in text as input and then outputs speech to a set of speakers. There are a number of text to speech software programs that enable any text on the screen to be selected with the keyboard or mouse. It is then spoken back to the user in a computer generated voice.

Sticky Keys (software)

Sticky keys is a feature available with most computers. It is an accessibility feature to aid users who have physical disabilities. Sticky keys allows the user to press a 'modifier' key such as Shift, Ctrl, Alt and have it remain active until another key is pressed.

Application software

The everyday programs that you use such as Microsoft Office, graphics packages and web browsers.

Hard Disk

The hard disk is the main storage device in your computer. It is a bit like a filing cabinet: all of your data files and applications software are stored on it. The hard disk contains a number of metal platters which have been coated with a special magnetic material. The data is stored in this magnetic material. Thus, the hard disk is known as a magnetic storage device. In order to access the data, the platters spin many thousands of times a second and a magnetic read and write head floats just above the surface of the platter. Necessary to support the way your computer works, large storage capacity, stores and retrieves data quickly, stored items not lost when you switch off, cheap cost per mb. However, slower to access data than ROM or RAM chips, can crash which stop the computer from working, attached to PC so not removed easily.

Magnetic Stripe Reader

The magnetic strip can hold personal details such as account number, and name. The strip can contain up to 60 characters, stored magnetically. To read the data on the card, it is 'swiped' through a Magnetic Stripe Reader machine and the data is read and fed back to the computer. Simple, cheap but limited storage capacity, not secure.

Operating System

The operating system is part of the system software. All computers have an operating system, they cannot function without one. The operating system is a program that allows applications software to communicate with the hardware. It sorts out where to store data on disk drives, deals with security - user names and passwords, organises files and folders, manages data transfer from the CPU to the peripherals e.g. printer, monitor, deals with saving, deleting, opening, closing files.

Dot Matrix Printer

The print head contains a grid of pins and different combinations of pins are pushed out to form different characters. The print head then hits a carbon ribbon leaving an imprint on the paper. This makes them fairly noisy as you can hear the pins striking the paper. Dot-matrix printers are ideal when you need carbon copies. This is because the print head hits the paper with enough force that when carbonised paper is used, the impact makes a copy on the second sheet. Cheap to buy and operate, can print on continuous stationary, create carbon copies. However, they are slow, noisy, can't print in colour and are not good quality.

Ink-jet Printer

These printers use cartridges that contain the ink, heating the ink as it flows through a set of tiny nozzles. Cheaper and more compact than a laser printer, cartridges cost less to replace than toners, produce good quality printouts better than a dot-matrix but not as good as a laser, faster than a dot-matrix but not as fast as a laser. However, noisier than a laser printer, can be extremely slow (colour), cost per page are more expensive than a laser printer, cartridges need to be replaced more often than a laser printer, ink will smudge while it is still wet.

Printer

They are used to create a 'hard' copy of your work i.e. something that you can hold, hand to someone else or file away. Ink-jets are good for low volume use as they produce excellent text and photo outputs, but cost-per-page can be very expensive, in which case a laser printer is the more cost-effectve choice.

Flash Memory

They consist of a small printed circuit board which is encased in plastic or metal casing. They usually Flash memory stickshave a removable cap which covers and protects the part of the stick which is inserted into a USB port. Hold 1Gb and more. Compact and portable, hold more data than a CD, reliable as they have no moving parts (unlike a hard disk), easily branded on their cover, not affected by magnetic fields. However, more expensive than CD or DVD, easily lost, metal part which is inserted into the USB port can be snapped.

Laser Printer

They print in the same way as photocopiers. Powdered ink, called 'Toner', is fused onto paper by heat and pressure. High quality printouts; better than ink-jet or dot-matrix, faster than ink-jet or dot-matrix, quieter than ink-jet or dot-matrix, cheaper cost per page than ink-jet or dot-matrix. However most expensive printer type, toner is more expensive than ink-jet cartridges, expensive to repair, bulky, can't make carbon copies.

Eye Typer (hardware)

This can be used by people who cannot use a hand or foot operated mouse and a conventional keyboard. A camera is mounted onto the computer and it is set to focus on the user's eye. The camera determines where the user is looking and monitors movements made by the eye. Mouse clicks are done with a slow eye blink.

Dialogue interface

This is a way of interacting with your environment by means of the spoken word.In order for these interfaces to work effectively they need to be 'trained' with the user. This involves the user speaking the commands until the system accepts the command and reacts appropriately. Allows for hands free control and good for physically disabled users. However, limited uses, expensive to develop, needs to be trained and background noise may interfere.

Predictive Text (software)

This is an input technology which is most commonly found on mobile phones and tablet computers. The technology allows words to be entered by a single or a few keypresses. Instead of having to type out the whole word, the software tries to predict the most likely word that you want.

Puff-Suck Switch (hardware)

This kind of switch is excellent for someone with limited physical mobility. You simply suck or puff down the tube in order to activate a switch. The switch itself is connected to the computer. Specific software running on the computer can take this input and act on it in any number of ways.

Problems with software and browsers

Unlike hardware, software standards are far less common. Standard committees have been formed, however, there is no obligation by any company to follow them to the exact letter! Problems in browsers: -Colours may appear different. -The size of the font may look different. -Script languages might work slightly differently in different browsers. -The browser may not recognise the font and may display a basic or standard font.

Joystick

You can move joysticks in many directions and the joystick tells the computer which direction it has been moved into. They also have one or more buttons whose position when pushed can be read by the computer. They give a better gaming experience for racing or flying styles of computer games. Joysticks are not particularly robust and can break easily if too much force is used on them.

Natural Language Interface

his type of interface allows the user to speak or type in their normal everyday language in order to interact with the computer, e.g. some applications such as speech recognition software accepts the spoken words and converts them into text on the computer. These applications have a much wider vocabulary than the dialogue interface. No training needed, more flexible, and good for physically disabled users. However, not widely available, very complex to develop, and unreliable. May require training to recognise the words correctly.