1. 1. 3 Input, Output and Storage

Question 1

Input, Output and Storage Devices

Answer 1

• Input device allows user to put data and info into computer
• Examples include Keyboard, Webcam, Barcode reader etc
• Output device converts info from computer into a human perceptible form
• Examples include Speakers, Printers, Projectors etc
• Storage device stores information on a computer

Question 2

Optical Storage

Answer 2

• Optical devices are read from and written to using lasers
• Binary info represented by Pits and Lands on disc
• Pits are recessed portions of the disc, scatter light, represents binary 0
• Lands are flat portions of the disc, reflect light, represents binary 1
• Examples of Optical Storage are CDs, DVDs and Blu-Ray

Question 3

Advantages and Disadvantages of Optical Storage

Answer 3

• Portable, Durable, Capacity, Cost, Reliable, Speeds
• CDs are small, thin, light weight, very portable, cheap
• Relatively slow transfer speeds, reliable
• Durable (can be flung and still be fine), easily damaged by scratches
• Limited storage capacity (CD-Audio files, DVD-Video, Blu-Ray-High-res film)

Question 4

Magnetic Storage

Answer 4

• Magnetic devices store information magnetically
• Represents binary info using magnetic state polarised (1) or unpolarised (0)
• Read/write head passes over regions, if polarised info can be read
• Examples of Magnetic Storage are Hard Disk Drive, Floppy disk and Magnetic Tape

Question 5

Advantages and Disadvantages of Magnetic Storage

Answer 5

• Reliable, Durable, Portable, Cost, Capacity, Speeds
• High capacities between 500GB to 5TB
• Relatively cheap, not very durable (will break if dropped)
• Reliable, not portable (bulky), somewhat slow data transfer speeds

Question 6

Solid State / Flash Storage

Answer 6

• Makes use of silicon semiconductors forming logic gates NAND and NOR to store charge
• Two states of charge, high or low, represent binary values True and False
• Examples of Solid State / Flash Devices are USB sticks and SSDs

Question 7

Advantages and Disadvantages of Solid State / Flash Storage

Answer 7

• Reliable, Durable, Portable, Speeds, Capacity, Cost
• Very reliable, quiet durable (won’t break when dropped a few times)
• Very portable, good read/write speeds, relatively good capacity similar to HDD
• Expensive per GB compared to Magnetic Storage

Question 8

RAM

Answer 8

• Random Access Memory, type of fast main memory
• Used to store data and programs that computer is currently using
• Speeds up computer’s execution, RAM has very high access speeds compared to secondary storage
• RAM more expensive per GB, computers often have 4/8 GB of RAM
• Volatile, loses info when power is lost (temporarily stores data while computer runs)

Question 9

ROM

Answer 9

• Read Only Memory, cannot be modified
• Useful for storing fixed sequences of instructions such as bootstrap
• Bootstrap is program that loads OS from HDD to RAM
• Non-volatile, retains data even when computer loses power

Question 10

Virtual Storage

Answer 10

• Allows info to be stored remotely, accessed by any computer over the internet
• Examples of cloud storage services, Google Drive, Microsoft One Drive
• Popular method of storage, convenient for file to be available “in the cloud”
• Requires internet connection with decent speeds, monthly subscriptions are costly