How they work
How they work
Note: You are not required to know how optical devices work for the IGCSE ICT Specification, but it probably helps you remember the advantages and disadvantages 🙂
CD
Compact Discs – CDs
CDs were introduced in the 1990s in order to fill the demand for a cheap and easily transportable method of data storage. They contain one of two types of data:
- audio data, readable by a CD player or a computer up to 70 minutes long
- binary data, readable by a computer , up to 700MB
Uses
- Music Albums
- Photo and documents backup
- Device driver & software shipped with hardware
Advantages
- Cheap per MB storage
- Easy and cheap to ship via the mail
- Wide compatibility
Disadvantages
- Not suitable for high resolution image / video backup
- Can’t store a full Movie on it
- Easy to scratch / break
- Slow read / write speed
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Digital Versatile Discs – DVDs
DVDs were introduced to fill the demand for higher capacity storage than was available using CDs.
They use a narrower laser beam, which allows more storage capacity than a CD.
Uses
- Feature length films (Full movies)
- Operating System storage
- Larger modern games / software
- Image and Video file backup
Advantages
- Larger storage capacity than CDs
- Can store full standard quality movies
- Faster R/W speeds than CDs
- Very cheap per MB storage
Disadvantages
- Can storage HD / 3D Movies
- Can’t do a full Hard Drive backups
- Can be scratched / broken easily
Blu-ray
Blu-ray
As games began to include larger open world environments and televisions increased their resolutions, there developed and increasing demand for larger storage capacity optical devices, and as a result the Blue-ray disc was invented.
Uses
- 3D and Full HD Movie Storage
- Games storage for high end games consoles
- HD movie and image backup
- Hard Drive backup
Advantages
- Only Optical disc large enough for hard drive backups
- Faster R/W speed than DVD/CD
Disadvantages
- Still not widely supported by many computers
Activity
Activity – The Story of Optical Media Presentation
Using Powtoon ( or other similar presentation / animation software ) create an animation showing the story of optical media.
Your animation should include:
- How Optical media works
- What the different optical media devices are, their uses and pros / cons.
- What lead to the development of the next technology