Hardware mindmap

Hardware
1. Input Devices
  1. Keyboard
    1. The most common input device to enter text, numbers and instructions into computers
    2. Disadvantages
      1. Users with limited arm/wrist use find keyboards difficult to use.
      2. slow when compared to direct data entry (e.g. optical mark recognition)
      3. takes up physical space
    3. braille keyboard
      1. The braille keyboard has raised dots to identify the keys. This will help the blind people input data into the computer.
    4. concept keyboard
      1. The concept keyboard uses icons or phrases instead of standard letters. They are often used in fast food restaurants, supermarkets, shops where a single key represents an item.
  2. Mouse
    1. Uses
      1. used for opening, closing and minimising software
      2. used for grouping, moving and deleting files
      3. very useful when editing images, for example controlling the size and position of a drawing
      4. to select icons
    2. Advantages
      1. enables rapid navigation through applications and the Internet
      2. are small and so takes up little physical space
    3. Disadvantages
      1. people with restricted hand/wrist movement can have difficulty
      2. difficult to use if there is no flat surface
  3. Touchpads
    1. Touchpads are used in laptop computers as a pointing device.
    2. Advantages
      1. enables rapid navigation through applications and the Internet
      2. integrated into the laptop, aids portability
      3. can be used when when there are no flat surfaces
      4. faster to select an option compared to using a keyboard
    3. Disadvantages
      1. people with restricted hand/wrist movement can have difficulty
      2.  more difficult to use when compared with a mouse
      3.  can be more difficult to use when doing certain operations such as “drag and drop”
  4. Trackerballs
    1. Uses
      1. has the same pointing/cursor control capability as a mouse
      2. used in control room environment where it is faster and more robust than a mouse
    2. Advantages
      1. easier for peope with limited hand/wrist movement
      2. since it is stationary, it takes up less desk space
    3. Disadvantages
      1. more expensive since they are not a standard equipment
  5. Remote Control
    1. Uses
      1. commonly found in home entertaiment devices
      2. used in industrial applications to remotely control processes, stop and start machinery, etc
    2. Advantages
      1. can be operated from a distance
      2. some chemical processes are hazardous, so it is safer to operate equipment from a distance
    3. Disadvantages
      1. people with restricted hand/wrist movement can have difficulty
      2. signal between the control and device can be easily blocked
  6. Joysticks
    1. most popular input device for computer games ,used in simulators (e.g. flight simulators) to mimic actual controls
    2. Advantages
      1. easier to control game actions
      2. can control game actions by varying the pressure, speed and direction of the joystick
  7. Touch Screens
    1. User chooses an option by touching the button/icon on the screen, without the need for any pointing device.
    2. Advantages
      1. faster data entry of options
      2. easier to choose options
      3. a user-friendly method for keying in data
      4. prevents people from keying in information which could potentially corrupt the computer system
    3. Disadvantages
      1. limited number of options available
      2. screen can get very dirty with constant touching
    4. Uses
      1. used where selections are made on screen used in PDAs mobile phones and satellite navigation systems
  8. Magnetic stripe readers
    1. The magnetic stripe found, for example, on the back of a credit card, debit card, ATM card contains useful information such as the account number, expiry date and start date.
    2. Advantages
      1. faster data entry
      2. error free since no typing is involved
    3. Disadvantages
      1. if the magnetic stripe gets damaged, the data is lost
      2. since the information is not human readable, this can be a disadvantage in some situations
  9. Barcode readers
    1. Uses
      1. used in supermarkets and other shops where the goods are marked with a barcode; libraries to scan library cards and books
    2. Advantages
      1. faster data entry and fewer mistakes
      2. enables automatic stock control
      3. when an item price is changed, only the central database needs to be updated. There is no need to change the prices individually on each item
    3. Disadvantages
      1. can be relatively expensive to administer
  10. Optical Mark Recognition (OMR)
    1. Uses
      1. used to read questionnaires, multiple-choice questions, etc where responses are in the form of shaded areas
    2. Disadvantages
      1. there can be problems if the forms are not filled in correctly
    3. Advantages
      1. a very fast way of inputting the results of a test, survey, etc
      2. more accurate than keying in the data since there is no typing
  11. Optical Character Recognition (OcR)
    1. Software that takes scanned text and converts it into a computer readable form.
    2. Disadvantages
      1. may not be accurate as system still has difficulty reading handwriting
    3. Advantages
      1. faster data entry
      2. depending on the source, number of errors is reduced since there is no manual data entry
  12. MAGNETIC Ink Character Recognition (MICR)
    1. Disadvantages
      1. only certain characters can be read
    2. Advantages
      1. no manual input, thus errors are reduced
    3. Read characters printed in a special ink. For example, the characters at the bottom of a bank cheque.
  13. Digital Cameras
    1. Advantages
      1. easier to produce better quality photographs than with a traditional camer
      2. memory card can store several hundred photographs
      3. easier and faster to upload photographs to a computer
      4. no need to develop film and print out photographs
      5. easy to delete an image from memory
    2. Disadvantages
      1. some artistry lost since software now corrects errors in the photographs (e.g. incorrect exposure, removal of red eye, etc)
  14. Webcams
    1. Disadvantages
      1. limited features and picture is often of poor quality
      2. needs to be connected to the computer (not so with laptops, though)
    2. Advantages
      1. allows people too keep in contact with each other without travelling
    3. Connected directly to the computer through a USB port and they do not have a memory. Used to enable video conferencing.
  15. Microphones
    1. Uses
      1. used to input speech/sounds to be used in various applications (e.g. presentation, special effects)
      2. used in voice recognition software (e.g. convert speech into text). This is useful for people with limited hand/wrist movement.
    2. Advantages
      1. faster to read in text than to type it in using a keyboard
    3. Disadvantages
      1. sound files can use up a lot of computer memory
      2. voice recognition software is not as accurate as typing in manually (e.g. cannot distinguish between words that sound alike)
  16. Sensors
    1. A device which measures some physical quantity which is continuously changing (e.g. temperate, light, etc) and inputs it to a computer. Sensors are usually used in monitoring and control applications.
    2. Disadvantages
      1. faulty sensors can give false results
    3. Advantages
      1. readings ar continuous, so there is no break in the monitoring
      2. readings are generally more accurate than readings taken by human operators
  17. Graphics Tablets
    1. Used with a stylus to produce freehand drawings. The images produced can then be stored in a file on a computer.
    2. Advantages
      1. an accurate method of drawing compard with using a mouse or a trackerball
    3. Disadvantages
      1. more expensive than other pointing devices, such as a mouse
  18. Light Pens
    1. Light-sensitive pen-like device that contain sensors that send signals to a computer whenever light changes are detected. It is placed against monitor when used and used commonly to edit digital images.
    2. Advantages
      1. easy to use
    3. Disadvantages
      1. problems with lag when drawing on screen
      2. only work with CRT (cathode ray tube) monitors at the moment
2. Output devices
  1. Monitor
  2. Printers
    1. Laser printers
      1. best for fast high quality high volumne printing
    2. Plotters
      1. can produce highly accurate, very large drawings (blueprints of buildings) and posters
    3. Inkjet printers
      1. printing may “smudge”
    4. Dot matrix printers
      1. an impact printer, alow, noisy and output is not good quality
      2. can produce carbon-copies
    5. Braille printer
      1. produce raised dots printouts to help blind people read output from computer
  3. Speakers
    1. can help blind/partially sighted people through audio output of text
    2. used to output sound from multimedia presentations

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Hardware mindmap

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