Edexcel IGCSE ICT Chapter 1: Hardware

Name a + and - of biometric scanners.

+: inaccurate -: minimize risk of fraud and theft.

Name 2 things required to use a keyboard effectively.

2 things required to use a keyboard effectively are being able to touch-type and knowing the layout.

Name 3 different types of printer paper.

3 different types of printer paper are: • Single sheets of A4 paper. • Continuous paper is perforated and can be easily separated into single pages. • Pre-printed stationery has information on the paper before computer printing. For example, the name and address of the company.

Name 3 input devices.

3 input devices are keyboards, mouses and scanners.

Name 3 output devices.

3 output devices are monitors, printers and speakers/headphones.

Name and explain 3 types of scanner.

3 types of scanner are: • Hand-held scanner - reads the image while being dragged over it. • Flatbed scanner - the image is laid flat on the scanner's surface. • Sheet-fed scanner - reads the image as the paper goes through the sheet feeder.

Name 4 types of computer.

4 types of computer are: 1. PCs (personal computers) 2. Mainframe computers 3 Minicomputers 4. Supercomputers

Name 5 Audio input devices and technologies.

5 Audio input devices and technologies are: - Touch-tone telephone - Microphone - Voice recognition software - Speech recognition —> voice command systems - Natural language processing

Name 5 pointing devices.

5 pointing devices are: 1. Mouse 2. Joystick 3. Tracker ball 4. Trackpad 5. Graphics tablet

Name 7 features of sound cards.

7 features of sound cards are: Polyphony - plays more than one sound or voice independently at the same time. • Output through one or more sound channels, e.g. mono, stereo (2 channels), or quadraphonic (4 channels). • Surround sound or 3D audio. • Improves the clarity of compressed audio files, e.g. mp3. • Built-in memory for faster sound processing. • USB, optical and other ports to connect to DVD recorders and other devices. • MIDI (Musical Instrument Digital Interface) to connect to electronic instruments.

Name 8 types of PC.

8 types of PC are: 1. Desktop 2. Laptop 3. Tablet/pad 4. Notebook 5. Netbook 6. Hand-held 7. Games console 8. Embedded computer.

What's a biometric scanner?

A biometric scanner reads a person's unique physical characteristics to identify them, e.g. face recognition. Biometric scanners can be used to control entry to buildings and used in place of car keys.

What's a computer?

A computer is an electronic machine that inputs data, processes it under the control of a stored program, and outputs information. While the data is being processed, data can be retrieved from or saved on backing storage.

How do digital cameras work?

A digital camera stores pictures on a memory card. These can be transferred to a computer or TV. Digital cameras have a small LCD screen or traditional viewfinder. The camera forms pictures from a mass of very small dots of different colours. Picture quality is related to the density of the dots.

How do digital video cameras work?

A digital video camera or camcorder records moving images with sound. Recordings can be saved on a memory card or built-in hard disk, and input to a computer.

What's a disadvantage to remote controls?

A disadvantage to remote controls is if the handset is lost or damaged, the device may not be useable.

Explain what a processor is.

A processor or microprocessor is built into a microchip that also has memory and other components built into it. The microchip itself is often referred to as the 'processor'. If there is more than one processor built into the microchip, then the microchip is referred to as the 'processor' and processors built into it are referred to as 'cores'.

How are users reassured the remote's working?

A remote control handset will often have two LEDs. One LED is the infrared transmitter and the light from this is invisible. The other emits a visible light to reassure the user that the remote control is working.

How do scanners work?

A scanner converts printed images on paper into electronic form. Scanners may read only particular types of image, e.g. a bar code scanner.

What's a smart card?

A smart card is a plastic card with a microprocessor chip embedded in it.

How do sound cards work?

A sound card controls all input and output of audio. Audio input through a microphone and output through speakers are usually analogue and the sound card handles their conversion into digital signals processed by the computer. It also handles digital audio input, e.g. from multimedia applications.

Describe touch screens.

A touch screen is used for output and input. You touch the screen to control the computer. Touch screens are mainly used with tablets and smartphones. There is no need for a keyboard but inputting text is slower.

How do touch-tone telephones work?

A touch-tone telephone makes a different beep depending on the button pressed. On the other end of the line, a computer inputs the beep and determines which button has been pressed. You may then listen to a voice response from the computer.

What's a webcam?

A webcam is a digital video camera used to view a remote location over the Internet. This may be for security purposes, interest or communication. Recordings can be made. Simple webcams have a fixed position but some webcams allow the user to turn them.

Name some + and - of audio input.

Advantages of audio input: • People speak to the computer and do not need to learn to operate a keyboard. Disadvantages: • Voice and speech recognition software has to be trained to recognise each person's speech. This can be a lengthy process. • Voice and speech recognition is not accurate because people pronounce words differently.

Name some advan. and disadvan. of printers.

Advantages of printers: • A printout is useful if no computer is available. Disadvantages: • Printing is slow and expensive compared with electronic communications. • Paper is bulky and deteriorates in storage. • Printed materials are more difficult to access and distribute, e.g. digital photos can be emailed and viewed on a multimedia projector.

Name some advantages and disadvantages of digital cameras.

Advantages: • Saved on a computer, so backup is easier and more reliable. • Sent by email. • Displayed on a wide variety of devices, such as smartphones and TV screens. • Broadcast over the Internet, e.g. on-demand TV programmes. Disadvantages: • Users store more photos and longer videos so more backing storage is needed. • High-quality photos and videos can be very large files. Sent by email or broadcast over the Internet they use more bandwidth and slow the network.

What are cashpoints?

Cashpoints are specialised computer terminals with a small screen, numeric keyboard and smart card reader.

How do computer outputs work?

Computer outputs work as follows: the computer communicates to the user, e.g. it displays graphics on the screen.

Describe how computers function.

Computers function as follows: 1. Input - data is entered into the computer. 2. Process - a computer is controlled by a program, that is, a sequence of instructions. It processes the input data automatically following these instructions. 3. Store - the program and data are stored, e.g. on a hard disk, for later retrieval. 4. Output - the computer communicates to the user, e.g. it displays graphics on the screen

How do computers process info?

Computers process info as follows: a computer is controlled by a program, that is, a sequence of instructions. It processes the input data automatically following these instructions.

What are interactive whiteboards?

Interactive whiteboards are large, touch-sensitive panels used as screens for multimedia projectors.

What are mainframe computers?

Mainframe computers are large computer, with huge processing power.

How do microphones work?

Microphones are used to input sound.

What are minicomputers?

Minicomputers are smaller versions of a mainframe.

Where are multimedia projectors and IWBs used?

Multimedia projectors and IWBs are used in school classrooms and at home to watch movies and play computer games.

How does natural language processing work?

Natural language processing uses speech recognition to interpret natural language, e.g. spoken English. You could use natural language processing to dictate a letter or give instructions to a computer.

What's a netbook?

Netbook's a very small laptop optimised for Internet and email access.

What's a notebook?

Notebook's a small laptop computer.

What's a numeric keyboard?

Numeric keyboards only have keys to input numbers and special characters. An example of a numeric keypad is an automated teller machine (ATM), also known as a cashpoint.

What are OCRs?

OCR (Optical Character Recognition) is used to input printed or handwritten characters without typing in the data. The characters are converted to text that can be word processed. This text needs to be checked carefully as character recognition is not always accurate.

What are PCs?

PCs or personal computers are microcomputers for individual use

What are photo printers used for?

Photo-printers are used to print digital photographs. A digital camera is connected to the printer or the camera's memory card is read in the printer. Pictures can be printed without using a computer.

Sound is needed, for example, to __________________ and for ______________________.

Play music; speech synthesis.

Where are plotters used?

Plotters are used in computer-aided design.

Name a + and - of plotters.

Plotters are usually more expensive to buy and slower than printers, but much larger sheets can be printed.

How do pointing devices differ from keyboards?

Pointing devices differ from keyboards as pointing devices make it easier to point and click but are harder to use to input text.

What are remote controls used for?

Remote controls are used to control TVs and garage doors and inaccessible or hidden devices.

What are sensors?

Sensors are used to input environmental data. • Examples of uses include recording light intensity, pressure and temperature. • Each sensor only detects one type of data. • Sensors usually produce a low analogue voltage which must be converted to a digital signal for the computer using an ADC (analogue-to-digital converter).

Name some - and + to laser printers.

Some - and + to laser printers are they're widely used (+) but are more expensive to buy than inkjet printers (-). Quality is excellent and they print quickly in monochrome or colour (+).

Name some benefits to sensors.

Some benefits to sensors are data logging and control as data can be continuously and reliably recorded in a form that can be processed by a computer, e.g. in weather stations and robotics. They can be placed in dangerous locations where people would be hurt and can record data that people do not sense accurately, e.g. humidity. Data can be collected frequently over networks from sensors in remote locations.

What's speech recognition software used for?

Speech recognition is often used for voice command systems. The speaker is identified and spoken words recognised as commands.

How do dot-matrix printers work?

dot-matrix printers are impact printers with a print head that is a matrix of steel pins. The pins strike a carbon ribbon making patterns of dots on the paper.

What are input devices?

input device is for putting in data to the computer.

Printed output is called ______________ or __________________.

printout; hard copy.

What's a game console?

Game console's a PC designed for playing games, e.g. Xbox. Has these features: • Graphics displayed very quickly • Large hard disk • Game controller, e.g. joysticks, buttons • Internet connection for online gamers

How do graphics tablets work?

Graphics tablets are a flat rectangular pad 15 to 76 cm (6 to 30 inches) wide. Move a stylus along its surface to produce line drawings. Mainly used for computer-aided design.

What are headphones?

Headphones are two small speakers built into a headset.

Describe magnetic stripe cards.

Information is stored on a magnetic stripe on a plastic card. The data recorded on the magnetic stripe can be input directly into a computer. Stripe cards can be used to control access.

Name two disadvantages to magnetic stripe cards.

Two disadvantages of stripe cards is that the data may be affected by electromagnetic radiation and data can also be copied or edited.

Monitors or ________ come in different ___________ with different _____________________________, __________________ and ______________.

Visual Display Units (VDUs), styles, screen resolutions, color quality, clarity.

What's voice recognition software used for?

Voice recognition software enables the computer to know who is talking but not what has been said.

How's a mouse work?

an optical mouse detects movement using light but some do this using a small rubber ball.

What's cache?

cache is RAM memory is built into the microprocessor.

Why might inkjet printers be better than other impact dot-matrix-printers?

Inkjet printers might be better than other impact dot-matrix-printers as Inkjet printers are non-impact and are quieter. They produce high- quality output in monochrome or colour.

How do inkjet printers work?

Inkjet printers spray tiny dots of ink onto the paper.

How's a flatbed plotter work?

A flatbed plotter holds the paper still while the pens move. Other plotters move the pens from left to right while the paper moves forwards and backwards.

What's a hand-held PC?

A hand held PC e.g. smart phone - fits into one hand and has a touch-sensitive screen. Can be temporarily attached to a keyboard.

What's a joystick?

A joystick's a lever that gives you similar control to a mouse. Joysticks are built into game consoles, which are mainly used for input but may have limited output, e.g. they vibrate.

What's a measure of print quality?

A measure of print quality is the dpi (number of dots per inch). The higher the dpi, the better the print quality.

What's a monitor screen made up of?

A monitor screen is made up of many dots (pixels or picture elements). The dots are so tiny you do not usually see them. A screen has a resolution of 1280 by 1024 if there are 1280 dots across the screen, and 1024 from top to bottom. Higher quality screens display more dots.

How do multimedia projectors work?

A multimedia projector projects the image displayed on a computer screen onto a larger, separate screen, which can be seen more clearly by a large audience.

Name the function of a plotter.

A plotter draws lines on paper using coloured pens.

What are OMRs?

An OMR (Optical Mark Recognition) reader recognises a mark made on paper so there is no need to type in the data. The mark's position determines its meaning. Marks must be very clear, or they may not be recognised.

Name an advantage and disadvantage to smart cards.

An advantage and disadvantage to smart cards are Smart cards can also be affected by electronic radiation and can be copied or edited but they are generally more secure than data recorded on a magnetic stripe.

What's the difference between an impact and non-impact printer?

An impact printer strikes through an inked ribbon onto paper. A non-impact printer uses a non-striking method to form the image on the paper.

What's an important feature of a processor?

An important feature of a processor is the speed at which it processes instructions. If you have more and faster cores, with a larger on-board cache, applications will run more quickly.

What's an input?

An input's data entered into the computer.

What's an output device?

An output device displays information from the computer.

What's an upright plotter use?

An upright plotter uses very long sheets of paper.

Name 2 examples of smart cards.

Bank and credit cards are usually smart cards, i.e. Chip and PIN (personal identification number) cards. wThey are used to pay for goods in shops and to withdraw cash at cashpoints.

What's data?

Data is raw, unprocessed information. Information is data that people understand.

What are desktops?

Desktops have these basic components: monitor, keyboard, system unit and mouse.

What's an embedded PC?

Embedded PC's designed for and built into equipment to perform specialised functions, e.g. a single microchip that controls a DVD player.

Compare LCDs and CRTs.

LCD (liquid crystal display) monitors have flat screens and are more compact than CRT (cathode ray tube) monitors. They consume less power than CRTs.

What are laptops?

Laptops are portable computers slightly larger than A4 size.

How do MFDs work?

MFDs (Multi-functional Devices) combine a printer, scanner and communications link to function as a printer, scanner, photocopier or fax machine.

Name some + and - of MFDs.

MFDs are much less expensive to buy than all the individual devices and use less space on the desktop. It is cost effective to replace them more frequently with modern technology. However, if part of the device is faulty, all the functions may be unavailable. If one function is being used, then the other functions are unavailable for other users.

What's MICR?

MICR (Magnetic Ink Character Recognition) is used to input specially shaped characters printed in magnetic ink. Forms can be pre-printed with data which can be read by a computer, but printing in magnetic ink is more expensive.

How do thermal printers work?

Thermal printers use heated wires to mark dots on the surface of a heat-sensitive paper.

How's storage used in the function of a computer?

Storage's used in the function of a computer as follows: the program and data are stored, e.g. on a hard disk, for later retrieval.

What are supercomputers?

Supercomputers are very large mainframes.

What's a tablet/pad?

Tablet's a very small portable computer with a touch-sensitive screen and no keyboard.

What's the FSB?

The front side bus (FSB) transfers data between the processor and memory.

What's the graphics card used for?

The graphics card (or video card) is housed in the system unit and controls the screen display. Higher quality cards have more colours and produce clearer graphics more quickly.

What are peripheral devices?

The peripheral devices attached to a computer system are for input, output or storage.

What's the processor you need depend on?

The processor you need depends on what you are going to do. For occasional word processing and email, an Intel Pentium Dual Core processor might be sufficient but for playing online multimedia games a faster Intel Pentium Quad Core processor is needed.

Describe how remote controls work.

The remote control technology used in the home is usually infrared. The transmitter built into the handset sends out a coded pulse of infrared light when a button is pressed. A transmitter is often a light-emitting diode (LED). A receiver built into the device being controlled inputs the code and passes it to a microprocessor that carries out the command.

Name the similarities and differences between MICRs and OCRs.

The similarities and differences between MICRs and OCRs are: • OCR and MICR both read printed characters. • OCR uses reflected light while MICR uses magnetic field patterns. • OCR recognises handwriting and different types of printed text but MICR only recognises specially shaped characters.

How do tracker balls work?

Tracker balls are like an upside-down ball mouse with the ball on the top. Move the ball with your thumb.