# Computing - Storage Devices

> Source: https://ollybritton.com/notes/a-level/computing/topics/storage/ · Updated: 2022-03-16 · Tags: school, computing, a-level

## See Also
- [Computing - Input & Output Devices](https://ollybritton.com/notes/a-level/computing/topics/input-and-output-devices/)

## Flashcards
### 2022-03-16
#### Optical Media
##### What is the device that reads and writes data from secondary storage??
The drive.

##### What is a drive??
A device that reads and writes data from secondary storage.

##### What is the media in relation to secondary storage??
What data is actually stored on.

##### What is the main principle of operation of optical storage??
Processing the reflections caused by shining a laser at pits and lands.

##### How are read-only optical storage devices (such as CD-Rs) initially written to??
A laser burns pits and lands.

##### How are read-write optical storage devices (such as CD-RWs) written to many times??
With a reversible chemical reaction.

##### In what direction is the data on an optical storage device read??
Spiralling from the inside-out.

##### What are some advantages of optical storage devices??
* Cheap
* Light weight
* Portable

##### What are some negatives of optical storage devices??
* Slow access times
* Prone to scratches

#### Magnetic Media
##### What makes magnetic media such as hard disks slow??
A moving drive head.

##### What is data actually represented as in magnetic storage??
Small regions that can be magnetised or demagnetised.

##### What makes tape worse than magnetic hard disks despite having more storage capacity??
Read/write times are very slow.

##### What are some advantages of magnetic storage devices??
* Cheap
* Large capacity

##### What are some disadvantages of magnetic storage devices??
* Slow
* Fragile

#### Solid State Media
##### How do solid-state drives store information??
As charges trapped in a floating gate between two oxide layers.

##### How do solid-state drives write information??
Running electrons past oxide layers.

##### What are some advantages of solid-state storage??
* Durable
* Fast access times

##### What are some disadvantages of solid-state storage??
* Expensive
* Limited reads and writes

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