Unit 2 Input Devices Flashcards
What is the definition of an input device?
Hardware that allows data to be entered into a computer.
How many types of input devices are there?
2 - manual input devices and direct input devices.
What is the definition of a manual input device?
A device that allows data to be entered into a computer by hand.
Give 5 examples of manual input devices.
keyboard, numeric keyboard, pointing devices, remote control, joystick, touch screen, scanner, graphics tablet, light pen, microphone, digital camera, web camera
What are keyboards used for?
To enter data into applications e.g. word processing applications such as Word.
To use enter commands e.g. keyboard short cuts such as CTRL + P to print.
What are the advantages of using a keyboard?
Enables fast entry of text into documents.
Very easy to use (you just press the keys)
Information instantly appears on the screen so you can check quickly that what you entered is correct.
What are the disadvantages of using a keyboard?
People with wrist or hand problems can find a keyboard painful to use.
Keyboards are quite large and can take up a lot of desk space.
Entering data is slow compared with other methods.
What are numeric keypads used for?
Entering numbers into a computer system.
Some numeric keypads allow you to enter simple text and symbols.
Uses of numeric keypads include: ATM machines, telephones, chip and pin devices.
What are the advantages of using a numeric keypad?
Faster than using a QWERTY keyboard.
They are small so they can fit easily on smaller devices e.g. a phone
What are the disadvantages of using a numeric keypad?
People with large hands can find them hard to use.
Difficult to enter text information.
What are pointing devices?
Pieces of hardware that are used to control a pointer or curser on a screen.
Frequently used with GUI
Used to input commands by selecting icons
What are the 3 main types of pointing devices?
Mouse
Touchpad
Trackerball
How many types of mice are there?
2
ball mouse - uses a ball under the mouse to detect movement
optical mouse - uses reflected light to detect movement
What are the uses of a mouse?
- opening, closing, maximising and minimising programmes and files
- Moving, grouping and deleting files
- Selecting icons and moving them around the page
- Editing images
What are the advantages of using a mouse?
Faster to select icons
Very easy to move pointer
Small and don’t take up much space
What are the disadvantages of using a mouse?
People with wrist problems may find them painful to use
Dirt can affect accuracy
Need a flat surface to work on
What are touchpads used for?
Replacement for a mouse - especially in laptops
What are the advantages of using a touchpad?
easier than using a keyboard
built into laptops
can be used even when there is no flat surface
don’t get clogged with dirt
What are the disadvantages of using a touchpad?
more difficult to control than a mouse
can be painful to use for people with wrist problems
drop and drag can be more difficult to perform
What are trackerballs?
similar to mice but the ball is on the top of the device rather than the bottom
What are the uses of trackerballs?
Used as an alternative to a mouse
Used in arcade gaming machines
What are the advantages of trackerballs?
People with wrist problems can still use them
More accurate than touchpads
Can be used when no flat surface is available
No limit on ball travel
What are the disadvantages of trackerballs?
More expensive than mice
More difficult to learn how to use than a mouse
What are remote controls used for?
Controlling other devices using infra-red signals e.g.
- changing the tv channel
- increasing/decreasing volume on a music player
- selecting a different chapter on a dvd player
- operating cranes with heavy
- activating explosives in demolition
- operating robot arms in hazardous chemical plants
What are the advantages of using remote controls?
Devices can be operated without having to go up to them - helpful for people with disabilities
Can operate devices in unsafe environments
What are the disadvantages of using remote controls?
People with limited hand movement can find them difficult to use
The infra red signal between remote and device can become blocked
What is the function of a joystick?
To control a pointer on a screen (similar to a mouse)
What are the uses of a joystick?
To control a pointer on a screen -
the handle moves the pointer
the buttons allow us to select or ‘click stuff’
What are joysticks used for?
video games
industrial machinery
simulators
What are the advantages of joysticks?
easier to control
simple to use and get used to
disabled people might be able to use them more easily
What are the disadvantages to joysticks?
Not as accurate as a mouse
Can be painful for people with wrist/hand issues
Difficult to enter text
What is the function of a touch screen?
Input commands into a computer by touching or pressing buttons/icons on the screen
What are the uses of a touch screen?
Mobile/smart phones PDAs Public information systems Interactive whiteboards Multiple choice tests
What are the advantages of using a touch screen?
fast and easy to use
no training needed to use them
What are the disadvantages of using a touch screen?
Limited number of options available on the screen
Expensive
Screens can become very dirty
What are the functions of scanners?
To enter information from a hard copy (piece of paper) into a computer
What are the uses of a scanner?
scans hard copies e.g. documents, photographs, certificates etc. into the computer
What are the advantages of scanners?
Very fast to enter hard copies
Very easy to scan and store
Easy to back up and duplicate
Damaged photos can then be repaired using graphic editing software
What are the disadvantages of a scanner?
Images are of lesser quality
Scanned images take up a lot of memory space
What are the functions of graphic tablets?
Allows designers to produce digital images much more accurately
Feels like drawing with a pen (the stylus)
What are the advantages of using a graphics tablet?
Much easier to draw images than with a mouse
Very accurate drawings can be produced
Fine detail can be added (unlike using a mouse)
Can be used where symbols are used instead of text
What are the disadvantages of using a graphics tablet?
Very expensive
Not able to enter data into a computer this way
What are the functions of light pens?
Quite old technology used instead of mice, touch screen or graphics tablets
Used for drawing directly onto a CRT screen (cathode ray tube)
What are the advantages of light pens?
More accurate than touch screens
Very small
What are the disadvantages of light pens?
Not as accurate as a graphics tablet
Can only be used with CRT screens
Can be uncomfortable to use
What are the functions of microphones?
Used to input analogue sound into a digital computer
What are the uses of a microphone?
Narration Voice over Speaking over the internet using VoIP e.g. Skype video conferencing Converting speech to text Hands free mobile phones
What are the advantages of using microphones?
Faster to input words than typing using a keyboard
Able to be used by disabled people who cannot use their hands
Makes driving safer
Very cheap to buy
What are the disadvantages of microphones?
Sound files take up a lot of storage space
Not as accurate as typing
Background noise can interfere
What are the functions of digital cameras?
Take photographs and digitally store them on a memory card
Preview photos and discard unwanted ones
Capture sound as well as picture
What are the uses of digital cameras?
Save special moments
Gather images for use in presentations
Transfer images to a computer for editing
Print images easily
What are the advantages of digital cameras?
No film to develop Unwanted images can easily be deleted Easy to make copies of images No need to print Can store thousands of pictures Can be easily transferred Can be easily edited
What are the disadvantages of digital cameras?
\need to have computer skills to use
Artistry can be lost - camera automtically corrects to what it thinks you want
What are the functions of web cameras?
Very similar to digital cameras but are directly connected to a computer and do not have memory storage
Used in face to face conferences such as Skype
What are the advantages of web cameras?
Allow long distance face to face conversations
Allow cheaper interviews and business meetings to take place
Can allow parents to keep an eye on their children from a different location
Can be used as as security device as can be left running constantly
What are the disadvantages of web cameras?
Image quality can be poor
Permanently fixed to computing device
Usually fixed so can’t move around
What is the definition of a direct input device?
Device with little or no human input needed.
Give 3 examples of a direct input device?
magnetic stripe reader chip and pin reader barcode reader optical marker reader (OMR) optical character reader (OCR) Magnetic Ink Character Recognition (MIRC)
What are the uses of a magnetic stripe reader?
ATM reader of bank cards
EFTPOS for transferring customer money
Hotel room keys
What are the advantages of using a magnetic stripe reader?
Very fast
No typing involved - therefore no errors
Not affected by water and are robust
Cannot be read by the eye so details on card are safe
What are the disadvantages of magnetic stripe readers
Can only hold a small amount of data
Need to have contact between the reader and card to work - cannot be used over the internet
If damaged all data is lost
Can be easily duplicated - cloning
What are the uses of a chip and pin reader
To make secure payments
What are the advantages of a chip and pin reader
More secure than magnetic stripe readers
Information is harder t clone
Can hold more data than magnetic stripe
Readers are portable
What are the disadvantages of a chip and pin reader
Might forget the PIN
People can look over shoulder and copy PIN if card was stolen
What are the uses of a barcode scanner?
Read information stored on a products bar code e.g. product Id number, manufacturer, country of origin
What are the advantages of a barcode scanner?
Quick and easy to change product prices
Quick and easy to get info onto a system
Very accurate
Automatic stock control
What are the disadvantages of a barcode scanner?
Expensive way to gather info
Bar codes can be swapped
Damaged bar codes can’t be read
What are the uses of an Optical Mark Reader (ORM)?
Reads marks made with a pencil, e.g. lottery ticket, multiple choice exams
What are the advantages of an ORM?
Quick
Accurate
Can save money
What are the disadvantages of an ORM?
Cannot be read if filled in incorrectly
Can only read shaded areas
Forms can jam
What are the uses of an Optical Character Reader? (OCR)
Can scan text on a paper into a computer. Converts scanned text to a digital format.
e.g. processing passports
What are the advantages of OCRs?
Very fast
Cheaper
Avoids typing errors
What are the disadvantages of OCRs?
Can find handwriting difficult to read
Not 100% accurate
Need to check errors manually
What are the uses of Magnetic Ink Character Recognition? (MICR)
MIRC can read special ink e.g. customer cheques
What are the advantages of MIRC?
Process cheques quickly
Greater security
Less errors as not manual input
Info can still be read even if someone writes over it
What are the disadvantages of MIRC?
Only a limited number of characters can be read
More expensive than other methods
What is a sensor?
A device that automatically inputs data into a computer system, where the data is constantly changing and can be measured.
What are sensors used for?
Measuring: Temperature Pressure Light Sound Humidity/moisture pH
What are the advantages of sensors?
Readings taken are more accurate
Sensors monitor constantly
Sensors respond to information immediately (burglar alarms)
No need of humans to operate sensor
What are the disadvantages of sensors?
Faulty sensors can give incorrect results e.g. reverse parking sensors
