1.1 Input, output and storage

Question 1

What are some optical storage devices?

Answer 1

BLUERAY – High-definition motion pictures as it has a greatest capacity
DVDR – Pictures / movies
DVDRW – High-definition motion pictures
CV – Music

Question 2

How does optical storage work?

Answer 2

Shining a laser at the media and processing the light reflected by the pits and lands as 0’s and 1’s

Question 3

PROS of optical storage

Answer 3

Positives:
Cheap
Lightweight
Portable

Question 4

CONS of optical storage

Answer 4

Prone to scratches
Slow access times

Question 5

What are some magnetic storage devices?

Answer 5

Tape (Small cough cough portable)
Magnetic disk drive

Question 6

How does magnetic storage work?

Answer 6

North and south polarity act as 0’s and 1’s, drive head runs over 0’s and 1’s and reads either a north or south pole, which makes a clicking sound.

Question 7

PROS of magnetic storage

Answer 7

Extremely high capacity
Cheap

Question 8

CONS of magnetic storage

Answer 8

Will eventually fail due to the drive head being a mechanical component
Slow access times
Fragile

Question 9

What are some solid-state storage devices?

Answer 9

USB memory sticks (portable)
Solid state drives

Question 10

How does solid-state storage work?

Answer 10

Flow of electricity forces elections into floating gates between 2 oxide layers, this causes a change in the charge in the oxide layers which its translated as 0’s or 1’s.

Question 11

PROS of solid-state storage

Answer 11

Positives:
Small
Lightweight
Very quick access times

Question 12

CONS of solid-state storage

Answer 12

Negatives:
Expensive (currently)
Limited read/writes

Question 13

Characteristics of ROM?

Answer 13

• Small piece of read-only memory located on the motherboard
• Non-volatile (instructions remain)
• Contains very first instructions for the computer (bootstrap)
• Used to load the basic input, output systems and to check the hardware is installed correctly

Question 14

Characteristics of RAM?

Answer 14

• Temporary storage of instructions and data for programs that are being executed by the processor
• Holds information being executed by the processor
• Volatile (instructions are lost)
• Much faster than the hard disk
• Holds the operating system

Question 15

Why does ROM need to exist?

Answer 15

• The system needs to load the operation system so it can start functioning
• The problem is the operating system is stored on permanent secondary storage – the hard drive
• At this stage, however, your computer isn’t even aware the hard drive exists

Question 16

What does ROM do in startup?

Answer 16

• It contains the bootstrap, a set of initial startup instructions placed in the ROM during manufacturing
• The first initial instructions perform a power-on self-test (POST)
• The POST sends signals to all connected components, wakes them up and makes the CPU aware of their existence