1.1.3 Input, Output and Storage Flashcards
1
Q
How do optical devices store data?
A
- Read from and written to using lasers. Lands reflect incident laser light, whereas pits scatter it, allowing 1s and 0s to be stored.
2
Q
How do magnetic devices store data?
A
- A read/write head passes over the region, polarising regions of the metal, or leaving them unpolarised, representing 1s and 0s.
3
Q
How do flash devices store data?
A
- Information is stored in a block consisting of pages. Each of these stores a charge of high or low, representing 1s and 0s.
4
Q
What are examples of optical devices?
A
- CDs are small and portable, but easily damaged and have a low capacity and transfer speed.
- DVDs are CDs with higher capacities due to better quality.
- Blu-Rays hold significantly more than DVDs, making them ideal for high quality films.
5
Q
What are examples of magnetic devices?
A
- HDDs have huge capacities due to their stacked disk platters, but have slow transfer speeds and can be fairly delicate.
- Magnetic Tape is bulky and outdated but good for archiving data.
- Floppy Disks are very portable but outdated and low capacity.
6
Q
What are examples of flash devices?
A
- SSDs are light, portable, fast and fairly high capacity. They are fairly robust, but have a very high cost and somewhat limited lifespan.
7
Q
What is the purpose of RAM and ROM?
A
- RAM is a type of fast access main memory. It is volatile, and expensive.
- ROM is small and read only, and used for storing fixed instruction sequences.
8
Q
What is virtual storage?
A
- Data is backed up and stored remotely over internet-accessed cloud systems. It allows high capacity safe storage at a cost, and also requires a good connection.