1. 3 - STORAGE: TYPES AND CHARACTERTISTICS

2. Digital Device Storage…
What do you store on:
Your phones?
On your computers?
Tablets?
Why do we need storage devices?
What could computers do without storage devices?

3. Big Picture - Storage In this topic, you need to understand:
the need for secondary storage
data capacity and calculation of data capacity requirements
common types of storage: optical, magnetic. solid state
suitable storage devices and storage media for a given application, and the advantages and
disadvantages of these, using characteristics: capacity, speed, portability, durability, reliability, cost

4. Learning Objectives By the end of today’s lesson, you will be able to:
Identify the need for and purpose of secondary storage
Describe common types of storage
Match storage devices to their type of storage
Explain the characteristics of common types of storage

5. Brainstorm
In pairs, list all the different storage devices that you can think of….. (don’t rub them off yet!)

6. What is Secondary Storage?
Long term storage of data, files, software, OS.
Why do we need to store these things?
To access it again later
To use software
To interact with the computer
What would happen without secondary storage?
Software would need to be installed each time we use it
You couldn’t save any files, data, images, videos etc permanently. X X

7. Secondary storage compared to memory
It is always slower to access data from secondary storage
Data stored in secondary storage is permanent so it is NOT lost when the power is turned off
Whereas….
Data stored in internal memory such as RAM is lost when you turn the device off
When you run a program, or load a file,
the data is copied from secondary storage into internal memory.
When you save a file, it is copied from internal memory into secondary storage

8. Types of Storage
Optical
Magnetic
Solid State/Flash

9. Optical A laser light creates marks in a pattern on the disk
A laser light detects where the marks are and translates this into a readable format

10. Magnetic
Read/write head moves across the medium and changes how magnetised that part of the medium is
E.g. one level of magnetism will be a 1, a second will be a 0

11. Solid State This is made of microchips (switches)
The state of the switches determine if a 1, or 0 is stored

12. Look back at your starter board
Identifying if each storage device that you wrote down is magnetic, optical or solid state.
Optical
Magnetic
Solid State/Flash

13. Possible Answers Device Magnetic Optical Solid state Hard Disk Drive
Solid State Drive
Blu ray
DVD ROM
SD Card
USB Memory Stick
CD ROM
Tape Drives

14. Characteristics of Storage Devices
Capacity
how much data can it store?
Speed
how fast can it access the data?
Portability
how easy is it to move it from one place to another
Durability
how well does it last e.g. if it is dropped
Reliability
how consistently does it perform
Cost
how much does it cost per KB, MB or GB?

15. Characteristics of Storage Devices
Type of device
Capacity
Speed
Portability
Durability
Reliability
Cost
Optical
Magnetic
Solid State
Based on your research and knowledge, rank each type of storage device: 1 is best > 3 is least good
Disclaimer: these rankings are ‘in general’, there are likely to be many individual devices that do not quite fit this pattern.

16. Characteristics of Storage Devices
Type of device
Capacity
Speed
Portability
Durability
Reliability
Cost
Optical 3 2
Magnetic 1
Solid State
1 is best > 3 is least good
Disclaimer: these rankings are ‘in general’, there are likely to be many individual devices that do not quite fit this pattern.

17. Now you need to: Log into Moodle Go to ICT & Computing
GCSE Computer Science
Computer Systems
1.3 - Storage
iBytes 3.1 Types of Storage
Download, save and then complete the work sheet Storage_L1
Next, complete the Storage Mind Map

18. Types of storage mind map
Complete the mind map with:
The three types of storage
A definition of each type of storage
A list of example devices
The characteristics for that type of device

19. Plenary: Look back at your table for Q5
Which of these devices can store the most data?
Which of these devices can store the least data?
Which of these devices is the cheapest per MB?
Which of these devices is the most expensive per MB?
Which of these devices is easiest to put in your bag and take with you?
Which of these devices is most likely to get damaged?