Input, Output And Storage Flashcards
What is an input device?
What is an output device?
Is one which can be used to put data and information into a computer.
Is one which can be used to send information from the computer
Examples of input devices :
Keyboard- used to put text into a pc
Webcam- a camera used by a computer to take photos and record videos
Magnetic stripe reader- used to read data from magnetic stripes on cards like credit/debit card
Barcode reader- used in supermarket checkouts and access control systems to read information from printed label and cards
Example of output devices:
Speakers-used to output sound from a pc
Printers- used to output information from a pc onto paper
Projector- used to project video content from a pc onto a screen
Can devices be categorised as high input output? + Example
Yes only a small number
Example- touch screen outputs info in a visual way like a monitor, while acting as a device for a touch input
What are the variety of different methods of storing methods
-Small quantities of information
-Large capacity storage
What are optical devices able to do?
-Read from and written to using lasers
-Binary info represented by portions of the disc which either reflect it scatter the incident laser light:
A pit scatter light is 0
A land reflects light is 1
-Pits and land are written in spiral tracks on the disc’s surface
Performance factors for both input and output devices:
Speed
Accuracy
Cost
Relevance to task
Features of a CD
-Stands for Compact Disc
-Use optical technology to store small quantities of information
-Most commonly used for audio files
-Can also be used to store text and digital images
-Small, thin and light so very portable
-Easily damaged by scratches
-Limited storage capacity
-Relatively slow transfer speed
Feature of a DVD
-Stands for digital versatile disc or digital video disc
-Higher storage capacity than CDs
-Suited to storing digital videos
-Also an optical device
Features of Blu-ray
-Five times as much storage than traditional DVDs
-Useful for storing high resolution films
Magnetic storage:
-Devices which store info magnetically show binary using 2 magnetic states:
1)Polarised
2)Unpolarised
-Most common type is hard disk drive
-Magnetuv tape aslinstores info magnetically
Features of hard disk drive
-Most have high capacities between 500gb - 1TB
-Rotate magnetic platters at high speeds under a read/write head in an actuating arm
-Most will have multiple platters stacked to maximise storage capacity
-Somewhat slow data transfer speed
-Many moving parts introduces tendency to be damaged by movement
Features of magnetic tape:
-First used to record computer data in the 1950s
-Popular storage medium though to the 1980s
-Long stretches of tape wound reels passed through readers
-A space consuming way to store data
Features of a Floppy Disk:
-A thin magnetic disk enclosed in plastic to protect the disk from the dust/dirt
-Thin size and low weight made them extremely portable
-Typical storage capacity of 1mb
Features of Flash
-Fast and compact
-Silicon semiconductor form the logic gates NAND and NOR
-Logic gates used to store electrical charges in 1 of 2 states: high or low
-Information stored in blocks, combines to form pages
-Preferred logic gate used for storing small quantities of data NOR
-NAND is the preferred technology for larger files
-Can be erased and reprogrammed electronically
-Is non-volatile
-Flasg memory is generally more expensive per gigabyte than other methods of data storage
