ICT Input-Output devices 2023

Dis-advantages of OMR (Optical Mark Reader)

1 - Because of the speed of the machine, paper jams can occur. 2 - Can only read the marks (i.e., it can't read or input any text). 3 - Dirt marks on the paper might be Misunderstood by the system as marks to be input.

Advantages of OMR (Optical Mark Reader)

1 - Extremely fast to input data. 2- It is more accurate more than using humans to check the paper.

Advantages of OCR (Optical Character Recognition)

1 - Fast and accurate as it avoids typing errors and is less expensive on labour.

Dis-advantages of Chip and PIN

1 - People tend to be careless when entering their PIN and people watching can see it. This called 'Shouldering' or 'shoulder surfing.' 2 - You can forget your PIN, meaning you can't make payment with that the card until you get a new one.

Dis-advantages of OCR (Optical Character Recognition)

1 - Possible difficulty when reading handwriting. 2 - Has to be checked for errors.

Advantages of Chip and PIN

1 - The information held is more secure than just the magnetic stripe because the chips difficult to read and chip is difficult to read, and chips are harder to clone. 2 - The computer chip can hold more information than the magnetic stripe can hold. 3 - Chip and PIN readers can be wirelesses, which means they can be brought to you when you are in a shop or restaurant, rather than you having to go to the tilly to pay.

Dis-advantages of RFID

1 - The range of RFID is limited to about three meters. 2 - RFID tags can be read by anyone with a reader such as hackers. 3 - They can be affected by other electronic devices in the area.

Advantages of Magnetic Stripe Readers

1- Fats data entry compared with keying in with a keyboard or keypad. 2- Error free (since no typing is involved). 3- Data on card can be altered if necessary. 4- Simple for people to use- no training needed. 5- Very inexpensive.

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.

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).

Sensors Advantages

1- More accurate readings taken compared to human operators. 2-Reading are continuous-no break in the monitoring. 3-It is not possible for a human to go to some places where readings need to be taken, like the inside of a reaction vessel, where chemical reactions take place.

QR (Quick response) Advantages

1- Quick to read. 2- Stores 100 times more information than a bar code. 3- Anyone can create a QR code using software. 4- Very versatile(multipurpose).Can contain different types of data. 5- Codes can be easily read by multiple devices, including smartphones.

QR (Quick response) Dis-advantages

1- Some people do not know what they represent or how to read them. 2- You need a smartphone with a camera and the app installed to be able to read them.

Advantages of RFID

1- The chips do not need to be positioned exactly on the scanner like a bar code. 2 - RFID devices work within a few meters of the scanner. 3 - At a supermarket, all of the items in a trolley could be read at once. 4 - RFID tags can be used for tracking items, e.g luggage or animals.

Bar code readers Dis-advantages

1- The technology is expensive. 2- Bar codes must be undamaged.

Bar code readers Advantages

1- Very accurate. 2- Updates stock control automatically so save times. 3- Saves time when product prices change as only the price data in the database will need updating once for each product. 4-Quick and easy to get data into the system.

Disa-advantages of Magnetic Stripe Readers

1- Very small storage capacity. 2- Data can be destroyed by magnetic field, e.g., by placing next to a speaker. 3- Insecure - criminals can easily obtain card readers and writers. 4- You need to be with the reader to use the card; cannot use a card with just a magnetic stripe over the internet, for example.

Light pen uses.

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

Sensors dis-advantages.

1-Faulty sensors can give 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).

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 airplane 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.

CRT monitor

A monitor with a cathode ray tube; CRT was used in the traditional TV sets and monitors.

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).

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).

Output Devices and their uses

Any device used to send data from a computer to another deceive, like, monitor, projector, speaker and printer.

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. What are the advantages and dis-advantages of light pen and stylus pen?

Touch Screen

Can be found on personal computers, laptops, tablets and smartphones. it is a display screen that is both an input and an output device. Advantage of Toch Screen:- 1. Easy to use. A user needs to taps an image on a screen. 2. Space saving as input and output devices are the same. 3. Cost effective for shops and restaurants as fewer staff are needed if customers can orders Dis-advantage of Touch Screen:- 1. Not suitable for inputting large amounts of data. 2. Not very accurate for selecting very small areas. 3. Disabled people can find them difficult to use if they cannot lift their arms or are sitting in a wheelchair and the machines are placed too high. 4. Hygiene problems with lots of people touching the screen.

QR (Quick response)

Codes can be scanned by a downloaded app on a smartphone. A quick response scanner consists of software and hardware, such as a smartphone and an app used to read and respond to the data stored in a QR code. They are most conveniently used on smartphones which can be easily positioned in front of the QR code. QR code: a type of two-dimensional bar code (in a square) that can store data such as URLs, Geotags, and links.

Chip and PIN Readers

Device used to read the data stored in the silicon chip of a credit or debit card to verify the personal identification number (PIN) entered by using a numeric keypad.

Printers and plotters

Devices that produce output onto paper and onto other materials. They produced "hardcopy".

Stylus pen

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

OCR (Optical Character Recognition)

Scans a typewritten or printed document and translates the images of the character into digital text that can be used on the computer. OCR software can also be used to read data from passports or identity card directly into a computer.

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).

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).

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.

dot-matrix printer

They tend to be slow, noisy and the output is not that good. 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. Dis-advantages:- 1. Very noisy. 2. Very slow, poor-quality printing.

Bar code 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. The information contained in a bar code on a typical supermarket product: 1- Country of origin number. 2- Manufacturer number. 3- Item number. 4- Check digit. The price of the item is NOT in the bar code.

laser printer

a printer that works by using a laser to 'draw' the required outputs onto a drum and uses toner to print the output onto paper. Laser printers are used when quality and speed of output are important. advantages of it: - 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 The dis-advantages of it: - 1- the reproduction of colour is not always as precise as it is with an inkjet printer. 2- They tend to be more expensive to buy than inkjet printer.

RFID (radio frequency identification)

an RFID reader uses radio waves to identify and track special tags attached to objects. RFID tag: radio frequency identification tag. Contains digital data that can be interrogated by and send the data to a reader device using a radio waves. We can find them used: 1- Merchandise in supermarkets or stores. 2- Shipping containers. 3- train carriages. 4- Expensive musical instruments.

Monitors

are often called 'computer screen' or 'displays' as they display the computer's interface and software that is running to the users so that they can interact with it using input devices such as keyboard and mice. 1- Older monitor CRT (Cathode ray tube) there were therefore very heavy and bulky causing them to take up a lot of space. 2- LCD (Liquid crystals Display) used in smartwatches and smartphones. 3- TFT (Liquid crystals covered by a thin film of transistors). 4- LED (Light emitting diodes)

3-D printer

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 finalized drawing is important into some special software that prepares it in a format that is understood by the 3-d printer.

Inkjet printers

create an image directly on the paper by spraying ink through tiny nozzles. 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. Dis-advantages:- 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).

Multimedia projectors

device that can project an image from a computer onto as large a surface as is necessary, often used in presentations. its main dis-advantage is that it relies on a powerful and expensive bulb to provide the pictures. These bulbs are fragile (breakable) particularly if the projector is moved while it is still hot.

OMR (Optical Mark Reader)

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