ICT IGCSE chapter 2 : Input and output devices

Remote control Advantages

1- Can be operated from any reasonable distance. 2- Some chemical processes are hazardous,so it is a big advantage to be able to select operations from a distance.

Mouse advantages

1- Doesn't need a large desk area when compared to a keyboard. 2- Faster way to choose an option than using a keyboard. 3- Very quick way to navigate through applications and the internet.

Joysticks Advantages

1- Easier than a keyboard to navigate the screen. 2- Control is more realistic than using a mouse.

Mouse Dis-advantages

1- Easy to damage. 2- Difficult t use if no flat surface is available. 3- Can be more difficult for people with restricted hand.

Multimedia projectors Advantages

1- Enables many people to see a presentation rather than crowding round a small computer screen. 2- Avoid the need for several networked computers.

Multimedia projectors Dis-Advantages

1- Expensive to buy. 2- Setting up the projectors can be a little difficult. 3-Images can sometimes be fuzzy.

Touch screen advantages

1- Faster entry of options than using keyboard or mouse. 2- User-Friendly.

Touchpad Advantages

1- Faster than a keyboard for choosing options. 2- There are no flat surfaces available. 3- It is integrated into the laptop computer there is no need for a separate mouse.

Numeric keypads Advantages

1- Faster than standard keyboards when entering numeric data. 2- Many are small devices (i.e, mobile phones ) they are portable.

Contactless Crad advantages

1- Faster transaction. 2-Customers do not have to worry about typing error.

Advantages of Direct data Entry (DDE) Devices

1- Fats data entry compared with keying in with a keyboard or keypad. 2- Error free(since no typing is involved). 3- No moving parts-so physically very robust.

Keyboard advantages

1- Fats entry of new text into a document. 2- Easy to use for most people. 3- Easier to do verification checks as the data is entered.

Numeric keypads Dis-advantages

1- Have small keys which can make input more difficult. 2- the order of the numbers on the keypad isn't Intuitive "easy".

Dis-advantages of Direct data Entry (DDE) Devices

1- If the magnetic stripe gets damaged the data is lost. 2- Doesn't work at a distance (card needs to be in close contact with the reader).

Scanner Advantages

1- Images can be stored for editing at a later date. 2- Much faster and more accurate than typing in document again.

Keyboards Uses:-

1- Input of data into application software i.e (text into word processors, numbers into spreadsheets,etc. 2- Typing in commands to the computer (for example, Print Scrn, Ctrl+S to save a file , etc.

Keyboard Dis-advantages

1- Large device that uses up valuable desk space. 2- Slow method when compare to direct data entry. 3-Difficult to use if the user has limited arm.

Sensors Advantages

1- More accurate readings taken compared to human operators. 2-Reading are continuous-no break in the monitoring.

Joysticks Dis-advantage

1- More difficult to control the on-screen pointer than mouse.

Chip and pin readers Dis-advantages

1- Need to be careful to ensure PIN isn't read by somebody else while typing it in.

Tracker-ball Dis-advantages

1- Not supplied with computers as standard, therefore more costly. 2- User may need training since it isn't standard equipment.

Uses of mouse:-

1- Opening , closing and minimizing software. 2- Grouping, moving and deleting files. 3- Image editing.

Touchpad Dis-advantages

1- People with limited hand find the device difficult to use. 2- More difficult to use when doing certain operations such as drag and drop. 3- Can be difficult to control the pointer when compared to a mouse.

Digital Cameras Advantages

1- Produce better quality photographs than the traditional camera. 2- Memory cards can store several thousands photographs.

TFT monitors Dis- Advantages

1- The angel of viewing is critical otherwise the image isn't clear. 2- Definition is not good as a CRT monitor.

CRT Monitors Advantages

1- The angle view is better than the TFT monitors. 2- They work with light pen in CAD/CAM applications.

Touch screen Dis-advantages

1- The screen get dirty with constant touching. 2- Limited number of options available.

CRT Monitors Dis-Advantages

1- They are heavy . 2- They run very hot and can cause fire if left unattended.

TFT monitors Advantages

1- They are lightweight and don't post the same risks as CRT monitors. 2-Consume less power and don't generate as much heat as a CRT monitors.

Tracker-ball Advantages

1- They are more robust than a mouse. 2- Needs less space desk space than a mouse or a keyboard. 3- Easier to use than a mouse if the operator is disabled.

Scanner Dis-advantages

1- They can be slow at scanning. 2- Quality can be limited depending in the resuscitation.

Contactless Crad Dis-advantages

1- Transactions are usually limited to a small maximum value. 2-They are more expensive than normal credit/debit cards.

Concept keyboard Uses

1- allow the user to to do fast data entry (no need to type the whole commands). 2- the keyboards are waterproof.

Digital Cameras Dis-advantages

1- images need to be compressed to reduce the amount of memory.

Chip and pin readers Advantages

1- more secure system (PIN typed in must match up with PIN stored on chip). 2- More Robust system than magnetic stripe cards.

Light pen uses

1- selecting objects on CRT Monitors. 2- Drawing on screen with CAD packages.

Remote control Dis-advantages

1-Difficult to use if the operator has limited hand. 2- It is easier to block the signal if,for example the walls in the building are very thick.

Sensors dis-advantages

1-Faulty sensors can given spurious results (sensors on the rear bumper of a car that monitors obstacles; if these become dirty, they may either not identify or give continuous alarm).

Inkjet printers-Advantages

1. High quality output. 2. Cheaper to buy than laser printers. 3. Very lightweight and have a small footprint. 4. Don't produce ozone and volatile organic compounds, unlike laser printers.

Laser printers Dis-Advantages

1. Only really fast if several copies are being made. 2. Colour laser printers tend to be expensive to run. 3. They produce ozone and volatile organic compounds(these have been linked to health hazards in the office).

Laser printers -Advantages

1. Produce very high-quality hard -copy output. 2. Printing is fast. 3. They can handle very large print jobs. 4. Toner cartridges last for a long time

What can be made by using 3-D printers.

1. Prosthetic limbs : can be made to fit exactly on to the injured body part. 2. Making items to allow precision reconstruction surgery (facial reconstruction following an accident). 3. in aerospace,manufacturers are looking at making wings and other aeroplane parts using 3-d technology. 4. Fashion and art - 3-D printing allows new creative ideas to be developed. 5. Making parts for items no longer in productions, for example, parts for a vintage car.

Inkjet printers Dis-Advantages

1. Slow output if several copies needed. 2. Can't do large print jobs(ink cartridges run out too quickly). 3. Printing can be expensive if used a lot (cartridges are expensive to buy).

Dot matrix printers -Advantages

1. They can be used in environment that would be a problem to laser or inkjet printers (dusty,dirty or moist atmospheres).? 2. Very cheap to run and maintain . 3. Easy to use if continuous is required, long print jobs such as wages slips.

Dot matrix printers Dis-advantages

1. Very noisy. 2. Very slow, poor-quality printing.

Sensors

A sensor is a device that input data to a computer; the data is a measurement of some physical quantity that is continuously changing (i.e temperature,light,moisture,etc.) Since computer only understand digital data (1s and 0s), the information from the senors needs to be converted; this is done using an analogue to digital converter (ADC).

Heaters

Actuators are connected to the switches that turns the heater on or off. Uses:- 1.Automatic washing machine to heat up the water if necessary. 2.Control the heating in a central heating system. 3. Temperature control in an automatic glasshouse.

Control applications Actuators

Actuators are transducers : are used to take signals from a computer and convert them into some form of motion. As part of the control process, digital signals are sent from the computer to an actuator to operate a device- usually conversion of the digital signal to analogue.(using CAD).

Contactless Crad readers

Allow the customers to pay for items worth to limited amount (10 rials) without entering their pin.

Ergonomic Keyboards

Are designed to reduce the health-related problems.

Video Camera

Are refereed as DV (digital video) cameras

Light pen

Are used with computers as an input device. They contain sensors that send signals to a computer whenever light changes are detected.The devices ONLY work with CRT monitors.

Monitors

CRT monitors are the least expensive type of monitor. Uses :- the user can see immediately what they are typing in.

Keyboards

Common Input device that lets the user enter text , numeric data and instructions into the computer. Most use the "QWERTY" layout.

Graphics tablet

Is used with a stylus to produce freehand drawing Used 1- To produce drawing, computer graphics,etc. 2- Used in computer-aided design (CAD)works.

Driving wheel

It's Uses: 1- Video/ computer games. 2- Used in simulators (car driving).

Joysticks

It's uses;- 1- Used in video/ computer games. 2- Used in simulation (flight simulators).

Types of Sensors

Sensors are used in both monitoring and control application. Types of sensors:- 1- Temperature sensors :-used in washing machine, central heating,glass house , ovens. 2- Pressure sensors: used in burglar alarm system, washing machine,environmental monitoring,robotics. 3- Light sensors: used in glass house, automatic doors,street lighting control. 4-Sound sensors : used in burglar alarm system,monitoring liquid and powder flow in pipes. 5-Humidity/moisture sensors : used in glass house, environmental monitoring, used in factories where moisture levels are crucial (for example, manufacture of microchips, paint spraying). 6- pH sensors : used in environmental monitoring,glass house , chemical processes.

Speakers

Speakers can be connected directly to a computer or a built into the monitor or casing (as in a laptop computer). Digital data from the computer is converted into analogue form(using a digital to analogue converter-DAC).

lights

The actuator is connected to the switch that turns the lights on or off. Uses:- 1.Security lights. 2. In glasshouses to control the lighting conditions.

Digital Cameras

The images are stored on a memory card and can be transferred to a computer by : 1- (Wi-Fi , Bluetooth). 2- Reading the memory card. 3-Using USB port.

Motors

The motors is turned on or off by the actuator. used in :- 1. Automatic washing machines (to make the drum rotate). 2.Cookers to switch on fans. 3. Control of robot arms in industry. 4.In computers to control fans,disk drives and DVD drives.

Multimedia projectors

The signal source is usually from a computer, television or DVD player. the image from the source is magnified and projected on to a large screen. Uses 1- Training presentations. 2-Advertising presentations. 3-Home cinema system.

Touch screen

The user can choose an option by simply touching a button/ icon in the screen. It's uses: 1- Interactive white boards in education. 2- Automatic teller machine (ATMs). 3- Police information system at airport.

Input Devices and their uses

These are hardware devices that allow data to be input into a computer.

Output devices

These are hardware devices that allow data to be output from a computer.

Direct data Entry (DDE) Devices

These are used to read information on the magnetic stripe found on, for example, the back of a credit or debit card. Uses:- 1- on credit / debit cards for use at ATMS or EFTPOS( electronic funds transfer at point of sale) terminals. 2- Security devices to allow entry to building, hotel rooms, etc.

Webcams

They are connected directly to the computer through a USB port. They are used to enable video conferencing.

Inkjet printers

They produce good quality hard copies.They don't have large buffers.

Dot matrix printers

They tend to be slow, noisy and the output is not that good.

Radio frequency identification (RFID) readers

Use radio waves to read & capture information stored on a tag.The tag can be read from a distance of several meters.

Barcode Readers

Used to read information in the form of a barcode. Uses:- 1-In Supermarkets and shops. 2-In Libraries to keep track of books on loan. 3-Used as a safety function in many companies to ensure that electrical equipment is checked on a regular basis.

Radio frequency identification (RFID) readers

Uses:- 1- Livestock tracking (so that the whereabouts of each animal on a farm is known; it also identifies which farm owns the animal). 2- Retail ( it is similar to barcodes but doesn't require any scanning; details, such as price, can be stored on the tag & then automatically read at checkout. 3-Admission passes (in the them park RFID cards eliminate the need to scan or swipe people before "rides",reducing the waiting time. 4- Libraries (books can be tracked in and automatically by readers at the library entrance; no need to scan bar codes or magnetic stripe cards).

Chip and pin readers

Uses:- 1- Where payments are made using cards (restaurants, supermarkets, travel agents, etc>)

Remote control

a device that can be used to control a machine or apparatus from a distance. It's uses : 1- Television, DVD players and sound players. 2- Used in industrial application to remotely control processes, stop and start machinery. 3- To control multimedia.

Tracker-ball

an alternate input device for a mouse used to select commands from a graphical user interface for people with restricted arm movements.

buzzers

are switched on or off by the actuator. uses:- 1. in cookers and microwave ovens to tell the operator when the cooking process is complete. 2. in burglar alarm systems to warn of intruders.

3D- printers

are unique in that they can create a three-dimensional object made of various materials. 1.A design is made using computer-aided design (CAD) software. 2.The finalised drawing is important into some special software that prepares it in a format that is understood by the 3-d printer.

Touchpad

are used as a pointing device in many laptop computers.

Numeric keypads

are used for entering numbers ONLY. Their uses :-. 1- Automatic teller machines (ATM). To key the pin or the amount of money. 2- Mobile phones. 3- Point of-sale (POS). 4-Chip and PIN devices. 5- Fast entry of numeric data into a spreadsheet.

Scanners

are used to enter information from hard copy (text,photographs) into a computer. It used to :- 1- Scan old/valuable documents/books. 2- scan in bar-codes at POS(Point of Sale).

Microphones

can be connected to a computer.The input sound is converted to an analogue signal and converted into an digital signal.Computer's sound card usually do this,it acts as as analogue to digital converter (ADC).

Pointing Devices

control the position of the cursor or pointer on the screen and allow the user to select options displayed on the screen.

optical mark reader (OMR)

is a device that can read marks written in pen or pencil. Uses :- 1- read qustuionnaires, multiple -choice examinations.

Magnetic ink character reader (MICR)

is a system that can read characters printed in a special ink.like reading the charecters at the bottom of a bank cheque.

Optical Character reader (OCR)

is the software that takes scanned text and converts it into a computer-readable form. Uses:- 1-Uses is the processing of passports and identity cards.

Concept keyboard

uses icons or phrases instead of standard letters. These are often used in fast-food restaurants, where a single key represents one item.