Input and output devices

• resistive touch screen: a touch screen that is sensitive to the pressure of your finger
• capacitive touch screen: touch screen that is sensitive to the static electricity from your finger
• OCR: optical character recognition scans a typewritten or printed document and translates the images of the characters into digital text.
• OMR: optical mark recognition detects marks made by a human on a paper
• QR scanner: a quick response scanner consists of software and hardware (a phone and an app) that can read a QR code
• magnetic stripe reader: a device used to read a magnetic stripe of a card, which contains data.
• chip and pin reader: device used to read the data stored in the silicon chip of a credit or debit card to verify the PIN.
• RFID: radio frequency identification, uses radio waves to identify and track special tags attached to objects

  RFID tags: contains digital data, small tags that can be directly attached to a product that sends data to a reading device using radio waves
• Advantages of magnetic stripe readers:

  Simple and easy to use.

  Inexpensive

  Quick data input

  No errors inputting data as its stored on the card

  Robust
• Disadvantages of magnetic stripe readers

  Small storage capacity

  Data will be destroyed if stripe is damaged

  easy to duplicate
• Advantages of chip and pin readers:

  Information is more secure as chip is hard to read and hard to clone

  Chip can hold more than magnetic stripe

  Chip and pin readers can be wireless
• Disadvantages of Chip and pin readers

  People can find out your PIN

  You can forget your PIN
• RFID tags have three elements: a scanning antenna, a decoder to interpret the data, the RFID tag itself
• Passive RFID tags use the power provided from the reader to transmit the data. Active tags are powered by their own battery
• Advantages of RFID

  RFID readers can read chips a few metres away

  You can write data to RFID tags as well as read them

  RFID tags can be used to track items, animals, etc
• Disadvantages of RFID

  Tags can be read by hackers who can read private information or clone the tags

  RFID scanning can be affected by other electrical devices in the vicinity

  Range of RFID is limited to 3 metres
• input device: any hardware device that sends data to a computer
• Advantages of OMR

  Extremely fast to input data

  Its more accurate than humans checking the data
• Disadvantages of OMR

  The sheets will not be read accurately unless properly in position to be read by the reader

  Dirty marks on the paper can be misinterpreted by the system as marks to input

  Can only read marks
• Advantages of OCR

  Can be a fast way of entering hard copy

  Can avoid typing errors

  Cheap
• Disadvantages of OCR

  Text produced isn't always accurate, if the hard copy has strange fonts/poor handwriting/is unclear/some smudged text

  information needs to be manually checked for errors
• Advantages of QR codes and scanners

  Versatile, can contain different types of data

  Codes can be read by multiple devices, including smartphones

  Anyone can create a QR code using software

  Stores a lot more information than barcodes
• Advantages of a bar code reader

  quick and easy to get data into the system

  very accurate

  updates stock control automatically so saves time
• Disadvantages of Bar code reader

  The technology is expensive

  bar codes must be undamaged
• acutator: device that causes another device or machine to operate
• laser printer: a printer that uses a laser to draw the required outputs onto a drum and uses toner to print the output on the paper
• inkjet printer: printer that works by squirting ink at the page out of different nozzles for different colored ink
• dot matrix printer: a printer that uses a set of pins to press an inked ribbon against the paper, creating the output out of dots
• Disadvantages of laser printer:

  More expensive than inkjet printers

  Reproduction of colors isn't as accurate as it is with inkjet printer
• Advantages of dot matrix printers

  Can be used on continuous/single sheets of paper

  low printing cost per page

  reliable and durable
• Disadvantages of dot matrix printers

  they are slow

  they are noisy

  poor quality output

  limited color capabilities

  more expensive than inkjet
• Plotters are different from printers as they use pens to draw the image
• Plotters print very accurately on large sheets of paper or other material like wood
• Plotters can take up more room than most printers
• 3D printer: Printer that prints layers on top of each other, eventually creating a 3D object
• Disadvantages of 3D printers

  expensive

  difficult to use

  high energy consumption
• Speaker: a device to enable you to hear sounds or music on your computer system
• information contained on a barcode:

  country of origin number

  item number

  manufacturer number

  check digit