Input and output devices Flashcards
What is a laser printer?
- Produce high quality hard copy outputs
- Use toner pressed on page to produce printed documents
- print large amount at a quick rate
- black/white/color
What is inkjet printer?
- better than dot matrix printer but not as good as laser printer
- ink is stored and delivered to paper through ink cartridges
Define dot-matrix printer
- Pins are pressed against an inked ribbon which produces an imprint on paper.
- slow, noisy, poor quality print out.
Define OMR
Optical mark reader - interpret pencil marks on a piece of paper
Pros and cons of OMR
- Input is faster and less expensive because there is no requirement to type the information
- Verification checks on the input are unlikely to carried out
- OMR must be printed very accurately
Define OCR
Optical character recognition - the identification of printed or written text characters by a computer
How OCR works?
Printed text is scanned and input to the computers which attempts to recognise the characters in it
Pros and cons of OCR
- Text printed on paper can be converted to electronic form and edited.
- Character recognition is not always accurate and the electronic text has to be checked carefully
Define MICR
Magnetic ink character recognition identifies data printed using a special magnetic ink
Pros and cons of MICR
Forms can be pre-printed with data which can be read by a computer - saves time.
- MICR characters have to be printed in magnetic ink and this is more expensive
- Characters printed in ordinary ink is not detected.
Define magnetic stripe card reader
Reads information from a magnetic stripe on the surface of a plastic card when it is swiped through the reader.
Pros and cons of magnetic stripe card reader
- Often used as a form of identification that is small and light and can be carried all the times.
- The data recorded on the magnetic stripe can be affected by electromagnetic radiation and can be copied or edited.
Define sensors
Used to input data about the environment into a computer
Pros and cons of sensors
- Sensors can record data that people do not sense
- Sensors cannot interpret data
What is the use of CPU?
It is the device that carries out software instructions
Describe RAM
It temporarily stores the instructions that the computer is running, and the data it is processing
Define cloud computing
Where users store their documents, programs and data on the Internet rather than their own computers
Advantages of cloud
Lower cost: free programs
Time saving: no time to installing software
Sharing data
Disadvantages of cloud
Security risks: data stored online is vulnerable to hackers and viruses
Decreased accessibility: no Internet, no access to documents and program
