Input & Output Devices (Edexcel IGCSE Ict)
Exam board Pearson Edexcel · IGCSEUpdated 2024-07-12
Input devices
Spec point —
1.4.2
What is an input device?
- Input devices are hardware components that **allow users to interact **with a computer system
- They enable the user to** input data or commands into the system**, which the computer then processes to produce an output
Types of input devices
| Input device | Use | Advantages | Disadvantages |
|---|---|---|---|
| Keyboard | Entering data into a computer | - Easy method of entering data - Very common | - Repetitive strain injury - Slow to enter data compared to direct data entry |
| Mouse | To select on screen objects | - Intuitive and precise control - Fast to make on-screen choices | - RSI (strain on wrist) - Requires flat surface - People with disabilities can find them difficult to use |
| Joystick | Moves sprites/characters around a game | - Enhances gameplay/simulation experience - Improve realism - Accurate | - Expensive - Limited use outside of gaming and simulators |
| Graphics tablet | Use a stylus to draw or write | - Precise - Natural feel - Ergonomic | - Cost - Learning curve - Battery life |
| Scanner | Convert paper documents to electronic | - Accurate reproduction - Easy to share and store - Combined with barcodes becomes a DDE | - Quality depends on resolution - High quality means can be slow |
| Digital camera | Taking photos/videos | - Vast amounts can be captured - No developing - Easy to share | - Storage compression can lead to a loss in quality - Need to be tech-savvy to use effectively |
| Webcam | Streaming images/video | - Real-time communication - Cheap - Multipurpose | - Image quality - Privacy concerns |
| Microphone | Input speech, sensor to pick up sounds | - Hands-free input - Can be used for voice recognition - Fast | - Variable quality - Verbal inputs can be inaccurate - Need to remember key words and/or phrases |
| Resistive touchscreen | Pressure causes layers to 'touch' Durable | - Intuitive - No need for a separate pointing device - Easy to keep clean | - Screens can get dirty - Easily scratched - Less precise than a mouse |
| Capacitive touchscreen | Conduct electricity Finger causes a change in electrical charge and can be measured precisely | ||
| OMR Optical Mark Recognition | Read marks on exam paper in pen/pencil | - Fast processing - Reduced human error | - Limited to specific forms - Cannot read handwriting - Form must be completed accurately |
| OCR Optical Character Recognition | Text to digital data | - Fast data entry - Accurate and less error prone | - Can struggle with complex layouts - Font dependent - Not always 100% accurate - Expensive |
| Barcode scanner | Reads barcode labels | - Fast and accurate - Low cost - Allows for automatic stock control - Tried & trusted | - Requires line-of-sight - Barcodes are easily damaged - Barcodes can be swapped/altered by consumers |
| Biometric scanner | Fingerprint/facial/voice/iris recognition | - Easier than passwords - More secure - Speed | - Privacy concerns - Expensive |
| Magnetic stripe reader | Debit/credit cards | - Fast - Simple to use - Secure (unreadable) | - Magnetic stripes can get damaged and become unreadable - Reader must be in close contact |
| Chip and PIN reader | Retail card payments | - Secure - Reduced fraud risk | - Requires PIN input - Potential for skimming - High payment limits an issue for stolen cards |
| RFID reader | Contactless payments | - Fast transaction (no pin) - Data wirelessly transferred securely - Retailers don't have to access customer credit/debit information | - Transaction limit is smaller - RFID signals can be read/intercepted |
| Analogue sensors | Measure environmental data e.g. temperature, light, sound, humidity etc. | - Generally accurate - Provides real-time information - Automatic - Can collect data from places where they may be threat to human life | - May require calibration - Data must be converted to digital data (ADC) - Data may need to be checked for accuracy |
Output devices
Spec point —
1.4.1
What is an output device?
- Output devices are hardware components that receive information from a computer system and present it to the user in a comprehensible form
- They enable the computer to communicate the results of processed data or commands
Types of output devices
| Output device | Use/features | Advantages | Disadvantages |
|---|---|---|---|
| CRT monitor | Display output from a computer Screen size is measured diagonally in inches Resolution is the number of pixels measured horizontally across the screen | - Large viewing angles - Can be used with light pens | - Run hot - Heavy - Consume more power (than other monitor types) |
| LCD monitor | - Low power - Lightweight - No flickering - No image burn-in | - Motion blur/ghosting - Colour & contrast variable from different viewing angles | |
| LED monitor | - No motion blur/ghosting - Low power - Long life | - More expensive (than LCD) - Contrast can be poor | |
| Laser printer | High volume printing Electronically charged toner Dry ink | - Fast - High-quality prints - Lower cost per page | - Expensive initial cost - Limited to flat surfaces |
| Inkjet printer | Home printing & photographs Uses wet ink separated into black, cyan, magenta & yellow Tiny dots **sprayed **onto paper | - Lower initial cost - High-quality prints - Ink can be refilled | - Slower - Higher cost per page - Ink may smudge |
| Dot matrix printer | Useful when printing** multiple copies** Paper is impacted through a ribbon of ink | - Low cost - Can print multi-part forms - Very good for long print runs | - Noisy - Low print quality - Slow |
| 3D printer | Create real-life versions of digital models | - Customisable designs - Rapid prototyping - Medical benefits | - Limited materials - Slow process - Counterfeit items easier to produce - Very expensive |
| Plotters | Create drawings & blueprints | - High accuracy - Can print on various materials - Inexpensive to run | - Slow - Expensive to buy - Large size |
| Multimedia projector | Output computer usually to much larger display | - Large display - Good for presentations - Space saving | - Requires darkened room - Expensive bulbs - Need separate audio - Quality is variable |
| Speakers | Output audio | - Range of sizes and power outputs - Immersive audio - Helps people with disabilities | - Expensive for higher quality output - Varying sound quality |
| Actuators | Control motors, pumps, switches etc. | - Precise movement - Programmable - Allow automatic control of many devices | - Requires power - Potential mechanical wear - Requires DAC interface |
Worked Example List two peripheral devices that could be used to input text by people who are unable to use a mouse and keyboard
[2]
Answer
Any two from:
- Microphone
- Touchscreen
- Trackpad
- (Graphics) tablet
- Camera / Eye tracker / Gesture sensor/reader
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