IGCSE ICT Topic 2 - Input and output devices

2.1.7 Digital cameras List advantages and disadvantages

Advantages- Easier to produce better-quality photos than with a traditional camera. Easier and faster to upload photographs to a computer rather than having to scan in hard copies when using traditional methods. Memory cards can store several hundred photographs. Disadvantages- Need to be computer literate in using the cameras properly; also, the transferring, storing and manipulating of the images. Some artistry lost since clever software now corrects errors in the photographs e.g. incorrect exposure.

Direct data entry (DDE) devices 2.2.1 Devices for reading information from cards Contactless card readers List advantages and disadvantages

Advantages- Faster transaction (15 secs vs 30 secs using magnetic stripe reader) The system uses 128-bit encryption to protect data. Customers do not have to worry about typing errors (such as incorrectly typing in a PIN). Disadvantages- They are more expensive than normal credit/debit cards. A thief with a suitable reader could monitor your contactless card transaction while standing at the counter with you, or just behind you. Can take money twice if the customer uses it as a chip and PIN card.

Input devices 2.1.1 Keyboards Concept keyboard List the advantages and disadvantages

Advantages- Much faster for making non-text selections such as menu choices on the till of a fast-food outlet. The keyboard is waterproof which can be useful where there is dirt or the risk of splashes. Disadvantages- Poor for text or numeric input - although some keyboards do include a numeric keypad so the operator can enter the amount sold. Limited to the options shown on the keyboard

2.2.6 Quick response (QR) codes List the advantages

Advantages- No need for the user to actually write down or key in a website address; this is done automatically by scanning the QR code. QR codes can store website addresses/URLs that appear in magazines, trains, buses or even business cards, providing a very effective method of advertising.

2.1.9 - Sensors List the advantages and disadvantages

Advantages- More accurate reading taken when compared to human operators. Readings are continuous - no break in the monitoring. Because it is a continuous process, any necessary action (control system) or warning (monitoring system) will be initiated immediately. Disadvantages- Faulty sensors can give spurious results (e.g. sensors on the rear bumper of a car that monitors obstacles; if these become dirty, they may either not identified an obstacle or give a continuous alarm).

2.2.5 Optical character recognition/reader (OCR) List what it does, the uses, advantages and disadvantages.

Takes scanned test and converts it into computer-readable form. Uses- Processing of passports and identity cards. Advantages- Faster data entry system that manually keying in data. Since no manual data entry. the number of errors is reduced. Disadvantages- The system has difficulty reading handwriting. Not a very accurate technique.

2.1.9 Sensors List the applications of the following types of sensors- Temperature, pressure, light, sound/acoustic, humidity/moisture and pH

Temperature - used in automatic washing machines, central heating systems, automatic glasshouse, ovens. Pressure - used in burglar alarm systems, washing machines, robotics, environmental monitoring. Light - used in automatic glasshouses, automatic doors, burglar alarm systems, street lighting control. Sound/acoustic - used in burglar alarm systems, monitoring liquid and powder flow in pipes. Humidity/moisture - used in automatic glasshouses, environmental monitoring, used in factories where moisture levels are crucial (e.g. manufacture of microchips). pH - used in automatic glasshouse, chemical processes, environmental monitoring

2.1.2 Pointing devices Touch Pad List the uses, advantages and disadvantages.

Uses- A touchpad is an input device which is usually found on a laptop computer. By dragging your finger over the surface of the touchpad, sensors underneath detect the movement direction and speed. Advantages- Useful for laptops when using a mouse isn't practical The pad's position is fixed compared to the keyboard, unlike with a traditional mouse Disadvantages- Takes practice and skill to control the position of the cursor using the touchpad Gloves cannot be worn i.e. in a clean room or industrial environment where gloves need to be worn.

Input devices 2.1.1 Keyboards Numeric keypads List the uses, advantages and disadvantages

Uses- Automatic teller machines (ATMs), where the customer can key in their PIN, amount of money, etc. Point-of sale (POS) terminals in case of the bar code reader fail to read the barcode- the number has to be keyed in manually by the operator. Advantages- Faster than standard keyboards when entering numeric data. Since there are many small devices( for example, mobile phones) they are very easy to carry around. Disadvantages- Sometimes have small keys which can be difficult for fast data entry

Output devices 2.3.3 Printers Dot matrix printers List the uses, advantages and disadvantages

Uses- Can be used in noisy environments and in applications where print quality isn't that important. Used in applications where multi-part stationary or the fact that they are an impact printer is of value(e.g. producing wage slips.) Advantages- Can be used in dusty/dirty or moist atmospheres where laser and inked printers can't. Carbon copies or multi-part outputs can be produced. Very cheap to run and maintain. Easy to use if continuous stationary is required (e.g. long print jobs like wage slips). Disadvantages- Very noisy. Cost more than an inkjet printer to buy. Very slow and poor-quality printing.

2.2.2 Radio frequency identification (RFID) readers

Uses- Livestock tracking (so that the whereabouts of each animal on a farm is known; it also identifies which farm owns the animal). Retail (it is similar to barcodes but doesn't require any scanning; details can be stored on the tag and the automatically read at a checkout - several bar codes can be scanned at the same time so speeds up checkout process). Admission passes. Advantages- No line of sight contact is necessary; the tags can be read from distance. It is a very robust and reliable technology. Very fast read rate. Disadvantages- Tag collision (this is when signals from 2 or more tags overlap, interfering with each other). Because RFID uses radio waves, they are relatively easy to jam or interrupt. It is relatively easy to hack into the data/signal transmitted by the tag.

2.2 Direct data entry (DDE) devices 2.2.1 Devices for reading information from cards Magnetic stripe readers - list the uses, advantages and disadvantages

Uses- On credit/debit cards for use at ATMs or EFTPOS (electronic funds transfer at point of sale) terminals. Security devices to allow entry to buildings, hotel rooms, etc. Advantages- Fast data entry compared with keying in with a keyboard. Error free. Secure (info not in human readable form). Prevents access to restricted/secure areas. Disadvantages- If the magnetic stripe gets damaged (e.g., due to exposure to a strong magnetic field) the data is lost. Doesn't work at a distance (card needs to be in close contact with the reader). Since the info is not human readable, this can be a disadvantage in some applications.

2.1.2 Pointing devices Mouse List the uses, advantages and disadvantages.

Uses- Opening, closing and minimising software. Grouping, moving and deleting files. Advantages- Faster way to choose an option than using a keyboard. Very quick way to navigate through applications and the internet. Doesn't need a large desk area compared to a keyboard. Disadvantages- Can be more difficult for people with restricted hand/wrist movement than using a keyboard. Easy to damage, older type of mouse quickly becomes clogged with dirt. Difficult to use if no flat surface available.

2.1.6 Scanners List the uses, advantages and disadvantages.

Uses- Scan in documents and convert into format for use in various software packages Scan in old/ valuable documents, books, thus protecting the originals. Advantages- Images can be stored for editing at a later date. Much faster and more accurate (i.e no typing errors) than typing in documents again. Disadvantages- Quality can be limited depending on how good a resolution the scanner is capable of. They can be slow at scanning, especially if the colour scanning mode is chosen or if the chosen scanning resolution is high.

2.1.12 Light pens List the uses, advantages and disadvantages

Uses- Selecting objects on CRT screens. Drawing on screen (e.g. with CAD packages). Advantages- Greater accuracy than touch screens. Small (can be used where space is an issue). Easy-to-use technology. Disadvantages- Problems with lag when drawing on screens. Small (good for small spaces.)

2.1.5 Touch screens List the uses, advantages and disadvantages.

Uses- Self-service tills, e.g. petrol stations. ATMs to choose from on screen options. Advantages- Faster entry of options than using keyboard or mouse. Very easy method for choosing options. Disadvantages- Limited number of options available. Can lead to problems if an operator has to use the system frequently (straining of arm muscles).

2.1.3 Remote control List the uses, advantages and disadvantages.

Uses- Televisions, satellite systems, DVD players and hi-fi systems all use remote controls to alter functions such as sound volume, on/off, change channels, open the disc drawer. Used to control multimedia systems Advantages- Can be operated from any reasonable distance, unlike, for example, a corded mouse which is restricted by the length of the cord. Some chemical processes are hazardous so is a big advantage to be able to select operations from a distance Disadvantages- Difficult to uses if the operator has limited hand/wrist movement It is easier to block signal if, for example, the walls in the building are very thick.

2.2.3 Magnetic ink character recognition/reader (MICR) List the uses, advantages and disadvantages

Uses- They are primarily used to process cheques in banking operations. When a cheque is presented its value is first printed on the cheque in the special ink. The cheques are then all gathered together (either at the end of the day or after some specified period) and then read using batch processing method. Advantages- Offer greater security than OCR since the printed characters cannot be altered. No manual input, so errors are reduced. The magnetic ink characters can still be read even if somebody writes over (e.g. signature) Disadvantages- Only certain characters can be read and the number of different characters is very limited. More expensive than other methods used in direct data entry.

Output devices and their uses 2.3.1 Monitors The film transistor (TFT) monitors

Uses- They are used as the primary output device for computers so the user can see immediatly what they are typing in. They are an integral part o laptop computers. Advantages- They are lightweight and don't pose the same risks as CRT monitors. They produce less glare than CRT monitors and also emit less radiation. They consume less power and don't generate as much heat as a CRT monitor. Disadvantages- The angle of viewing a TFT is fairly critical otherwise the image isn't very clear. Definition is sometimes not as good as a CRT monitor.

2.1.8 Microphones Uses, advantages and disadvantages

Uses- To input speech/sounds to be used in various applications, for example in presentations, sampling (In films, music, etc.) and special effects (films) Input in voice-recognition software: The software converts the speech into text that can be used in, for example, a word processor or to input commands into a computer. To recognise commands: for example, some cards now have voice-activated systems to switch on the lights, turn the radio volume up/down etc. Advantages- Faster to read text than to type it in using a keyboard. It is possible to manipulate sound in real time using special software rather than work on a recording done at some earlier stage. If used in voice activation system, it has the advantage of improving safety. Disadvantages- Sound files can take up a lot of computer memory. Voice recognition software isn't as accurate as typing in manually( for example, the software can distinguish the difference between 'their' and 'there'.

Output Devices 2.3.2 Multimedia projectors

Uses- Training presentations( to allow whole audience to see images from a computer). Advertising presentations. Home cinema systems. Advantages- Enables many people to see a presentation rather than crowding round a small computer screen. Avoids the need for several networked computers. Disadvantages- Images can be fuzzy. Expensive to buy at start. Setting it up can be difficult.

2.1.2 Pointing devices Trackerball List the uses, advantages and disadvantages.

Uses- Used in applications where the user has a disability (such as RSI). Advantages- Doesn't need the same fine control as a mouse. Easier to use than a mouse if the operator is diabled. More accurate position of the pointer on screen than a mouse. Disadvantages- Not supplied with computers as a standard, therefore more costly. User may need training since it isn't standard equipment.

2.2.6 Barcode reader List the uses, advantages and disadvantages.

Uses- Used in supermarkets and other shops where the goods are marked with a barcode; enables automatic stock control, itemised billing etc. Used in libraries to keep track of books on loan. Used as a safety function in many companies to ensure that electrical equipment is checked on a regular basis. Advantages- Much faster than keying n data manually and fewer mistakes will be made. If used a sa way of recording data, they can improve safety. They allow automatic stock control. Tried and trusted technology. Disadvantages- Relatively expensive system to administer. Not foolproof (barcodes can be swapped around on items). Can be more easily damaged than RFID tags or magnetic strips.

2.1.4 Driving wheel List the uses, advantages and disadvantages.

Uses- Used in video/computer games. Used in simulators to mimic actual vehicle controls. Advantages- Easier than a keyboard or joystick to control steering movements, more natural. The 'driving experience' is more realistic. Disadvantages- It can be a rather expensive input device compared to mouse or joystick. Movements in the steering can be too sensitive, giving an unrealistic 'feel'.

2.1.4 Joysticks List the uses, advantages and disadvantages.

Uses- Used in video/computer games. Used in stimulators (e.g. flight simulators) to mimic actual controls. Advantages- Easier than a keyboard to navigate the screen. Control is more realistic than using a mouse. Disadvantages- More difficult to control th on-screen pointer than with other devices, such as a mouse.

2.1.10 - Graphics tablet List the uses, advantages and disadvantages

Uses- Used to produce, drawings, computer graphics, etc. In countries where the written language uses complex characters (for example, China and Japan) graphics tablets are used as a form of input as it is faster than typing in the characters with a keyboard. Used in computer aided design work. Advantages- It is possible to modify drawings before they are input. They offer a very accurate method of drawing (better than using a mouse or tracker ball). Disadvantages- They are more expensive than other pointing devices (for example a mouse). It takes longer to produce a drawing using this equipment than doing it with pen and paper.

2.2.4 Optical mark recognition/reader (OMR) List uses, advantages and disadvantages

Uses- Used to read questionnaires, multiple-choice examination paper and many other types of form where responses are registered in the form of lines or shaded area. Advantages- Very fast way of inputting the results of a survey, etc. The documents are fed in automatically and there is no user input. More accurate than keying in the data. They are more accurate than OCR methods. Disadvantages- The forms need to be carefully designed to make sure that the marks/shading are correctly positioned to gather accurate information. There can be problems id the forms haven't been filled in correctly;sometimes they have to be checked manually before being read, which is both time consuming and expensive.

Output devices 2.3.3 Printers Inkjet printer List the uses, advantages and disadvantages

Uses- Used were low output volumes are required. If high-quality printing is required for single pages these printers are ideal. 3-D inked printer ar enow being used in industry to produce prototypes. Advantages- High-quality output. Cheaper to buy than laser printers. Very lightweight and have a small footprint. Don't produce ozone and volatile organic compounds, unlike laser printers. Disadvantages- Slow out put if several copies needed. Can't do large print jobs (ink cartridges run out too quickly). Printing can smudge. Can be expensive if used a lot (ink cartridges are expensive to buy).

Output devices 2.3.3 Printers Laser printers List the uses, advantages and disadvantages

Uses- Used where low noise is required (e.g. in an office). If fast, high-quality, high-volume printing is required then the laser printers are the best option. Advantages- Printing is fast (when printing a lot). Can handle large print jobs. High consistent quality. Toner cartridges last for a long time. Disadvantages- Only really fast if several copes are being made. Colour laser printer are expensive to run. They produce ozone and volatile organic compounds ( linked to health hazards in the office).

Direct data entry (DDE) devices 2.2.1 Devices for reading information from cards Chip and PIN readers List the uses, advantages and disadvantages

Uses- Where payments are made using cards (restaurants, supermarkets, travel agents etc.) Advantages- More secure system, (PIN typed in must match up with PIN stored on chip). More robust system than magnetic stripe cards. Disadvantages- Fraud- need to be careful to ensure PIN isn't read by somebody else while typing it in.

2.1 - Input devices and their uses 2.1.1 Keyboards List the uses, advantages and disadvantages of keyboards.

Uses- Input of data into applications software Typing in commands to the computer (e.g. Prnt Scrn) Advantages- Fast entry of new text into a document Easy to use Disadvantages- Can be difficult to use if the user has limited arm/wrist movement. Slow method when compared to direct data entry (e.g. optical mark recognition) Large device uses up space

2.1.11 Webcams List the uses, advantages and disadvantages

Uses- Many people use webcams as a more personal way of having a conversation while chatting online. They are used to enable video conferencing to take place. Advantages- They can be left on constantly, only being activated as required; this means it is possible to have an immediate face-to-face video chat much like the instant messaging with images. They allow people to keep in contact with each other without the need to travel. Disadvantages- They have very limited features and are often of poor quality. They need to be connected to the computer (although this is less of an issue with laptop computers when the webcam is usually built into the monitor lid).

2.3 Output devices and their uses 2.3.1 Monitors CRT monitors List the uses, advantages and disadvantages.

Uses- They were used as the primary output decide for computers so the user can see immediately what they are typing in. They are used with light pens. for example, to allow design to be created on screen. Advantages- The angle of viewing is still better than with most TFT monitors. They work with light pens in CAD/CAM applications. Disadvantages- They tend to be rather heavy and present a safety hazard if not supported properly. They run very hot and can cause fires if left unattended. They consume more power than TFT monitors. Can flicker, which can lead to headaches and eyesight problems with prolonged use.