Input, Output and Storage Flashcards
What are some examples of Input devices
Keyboard
Webcams
Magnetic stripe readers
Barcode reads
Touch Screen (input and output)
What are some examples of Output devices
Speakers
Printers
Monitors
Projectors
Touch Screen (input and output)
What are some performance factors of input and output devices
Speed of data transfer
Accuracy
Cost
Relevance to Task
How does Optical Storage hold data?
Read from and written to using lasers.
Binary represented with Pits or Land.
Pits will scatter light, representing 0
Land will reflect light, representing 1
What are examples of Optical Devices?
CD
DVD
Blu-Ray
What are CDs?
Compact Disc
store small quantities of data
Describe CDs
Compact Disc
store small quantities of data - commonly used for audio files, text and images.
Small, thin and light.
Easily damaged
Relatively slow transfer speeds
Describe DVDs
Digital Video Disc
High storage capacity - usually stores videos
Describe Blu-Ray
5x as much storage as DVDs
Generally used for high-res films
What are the different types of Storage?
Optical
Magnetic
Flash
How does Magnetic Storage hold data?
Represents binary using two magnetic states, polarised (1) or unpolarised (0)
If an area is polarised, it can be read by a read/write head passing over the region.
What are the different Optical Storages?
CD
DVD
Blu-Ray
What are the different Magnetic Storages?
Hard Disk Drives
Magnetic Tape
Floppy Disks
Describe Hard Disk drives
Rotate magnetic platters at high speeds under a read/write head.
High storage capacity (500GB-5TB)
Describe Magnetic Tape
Long stretches of tape wound into reels and passed through readers.
First used to record computer data in 1950s
Popular until 1980s.
Describe Floppy Disks
A thin magnetic disk enclosed in plastic to protect the disk from dust and dirt
What is Flash memory?
Uses silicon semiconductors forming from logic gates NAND and NOR to store charge in two states - high (1) or low (0).
Information stored in Blocks, which combine to form Pages.
NOR is used to store small quantities of data.
NAND is used for larger files - like photos and video.
Give an example of Flash storage
Solid State Drives (SSD)
What are some advantages of Solid State Drives?
Light and portable
No moving parts
Very fast data transfer speeds
What are some disadvantages of Solid State Drives?
Expensive
Limited Lifespan - when a page is written to, the voltage require increases
What are some advantages of Floppy Disks?
Thin and and low weight - very portable
Typical storage capacity of 1MB
What are some disadvantages of Floppy Disks?
Dust and Dirt will damage data and can lead to corruption
What is a disadvantage of Magnetic Tape?
Takes up a lot of space
What is a disadvantage of Optical Storage
Scratches will damage data
