INPUT AND OUTPUT DEVICES

INPUT AND OUTPUT DEVICES

1. INPUT DEVICES

   • Keyboard
     • A keyboard is used to type text into the computer.
     • Excessive use can cause repetitive strain injury (RSI)
     • Disabled people often find keyboards difficult to use
   • Touch screens
     • It allows users to interact with computers using their hand or a specially designed pen called a stylus.
     • It's tiring to use for long periods
     • It causes eyestrain
   • Mice
     • A mouse is the standard pointing device on most desktop computers
     • Excessive use can cause repetitive strain injury (RSI)
     • It can also cause numbness in your fingers
   • Microphones
     • A microphone allows sound data to be input into the computer.
   • Game controllers
     • Joysticks and game pads are two common input devices used by game players.
     • Some people find joysticks more difficult to control than a traditional mouse
     • It can cause thumb soreness
   • Touch pads
     • In touch pads, you move the pointer by tracing your finger across the pad.
     • Can also cause RSI
     • Very short finger movements are required to move the cursor
   • Trackballs
     • A trackball consists of a relatively large ball which is fixed in place so that the user can spin it around, controlling a pointer on the screen.
     • A trackball is much more usable than a mouse for people with movement difficulties in their arms or hands.
     • It's more expensive than a normal mouse.
   • Barcode scanners
     • A barcode scanner is an automatic input device which is used to scan or read the barcode by using a visible red light.
     • Supermarkets can easily keep track of their stock,
   • Smart cards
     • Smart cards are plastic credit card style cards.
     • The data in a smart card is encrypted for increased security.
     • It can easily be damaged.
   • Magnetic stripe readers
     • Magnetic stripes are usually found on the back of most credit cards, membership cards, etc. To read the data on the card, it is swiped through a magnetic stripe reader machine and the data is read and fed back to the computer.
     • It's not so safe as thieves can obtain the readers and read the data on the card.
     • There is very limited storage capacity for data.

2. OUTPUT DEVICES

   • Screens
     • Screens are one output device found in all computer systems.
     • Eyes can become strained if you look at a computer screen for a long time.
   • Inkjet printers
     • An inkjet printer produces hard copies of documents and files.
     • Printing speed is slow.
     • It gives high quality output.
   • Speakers
     • A speaker is used to output sound from a computer
     • The sound can disturb others who are trying to work.
     • They can help blind people use the computer because text can be converted into sound.
   • Projector
     • A projector is used to project the video output from the computer onto a wall or a screen.
     • It can be used to present to a large audience.
     • The image quality may not be so good when projected
   • Television
     • It is used for transmitting and receiving moving images and sound.
     • Can be educational.
     • Sometimes, children can be exposed to inappropriate content.
   • Plotter
     • A plotter is a special type of printer which is able to draw high quality images on very large pieces of paper
     • It takes up more space than a normal printer.
     • It works on large sheets and still produces high quality output.
   • Headphones
     • They are a small pair of small loudspeakers used to output sound
     • Using it at a very high volume can cause temporary or permanent deafness.
     • They can be used to prevent other people from hearing the sound for privacy or to prevent disturbance.
   • Disk drives
     • This disk is fixed inside the computer and cannot be easily transferred to another computer.
     • They can crash, which stops the computer from working.
     • A disk drive allows a computer to read from and write onto computer disks.
   • Floppy disk
     • A floppy disk is a disk storage used to store data.
     • It has a small storage space.
     • The rate of data transfer is slow.
   • Automotive navigation system
     • Can lead to accidents due to misdirection.
     • It is a satellite navigation system designed for use in automobiles
     • It's not so cheap