10. OCR A Level (H046-H446) SLR3 - 1.1 Magnetic, flash and optical storage

Summary

This video delves into various storage devices, focusing on magnetic, flash, and optical media. It explains how each is used for different applications, from music and film distribution to data backup. Optical storage, like CDs and DVDs, is praised for its portability and cost-effectiveness, while magnetic media, including hard disks and tapes, offers high capacity. Solid-state drives (SSDs) are highlighted for their speed, durability, and increasing popularity. The video also discusses scenarios for choosing the right storage solution, emphasizing factors like capacity, speed, portability, and cost.

Takeaways

• 💿 Optical storage devices like CDs, DVDs, and Blu-rays use a laser to read data from physical pits and lands on the media, and are popular for music and movie distribution.
• 📀 Writable optical drives, such as CD-RW and DVD-RW, use a reversible chemical reaction to change the media's composition, allowing data to be written and rewritten multiple times.
• 🧲 Magnetic storage devices, including hard disks and tapes, use magnetization to store data, with hard disks being more common in computers and tapes once popular for backups.
• 🔋 Solid-state drives (SSDs) are gaining popularity due to their small size, quick data access, and silent operation, and they store data by trapping electrons in floating gates.
• 🚫 Optical media is prone to scratches and slow data access due to the spiral reading pattern from the center outward, making them less ideal for quick data retrieval.
• 🔄 The lifespan of SSDs is limited by the number of read/write cycles due to the deterioration of oxide layers over time.
• 💼 For high-capacity, non-portable storage needs, such as in an office desktop computer, magnetic media is often the best fit due to its large storage capacity and lower cost.
• 🎥 In scenarios requiring quick data transfer and durability, like a helmet-mounted camera, solid-state drives are ideal due to their speed, portability, and reliability.
• 🏞 For backup purposes, especially when portability and medium cost are concerns, magnetic media like external hard drives or tapes can be a suitable choice.
• 🎮 Optical media is a good choice for distributing video games due to its portability, durability, and lower cost, though cloud-based options are becoming increasingly popular.
• 🎵 For portable music players, solid-state storage is often the best option due to the need for portability, quick file access, durability, and reliability, despite the higher cost per byte.

Q & A

What are the different types of optical storage devices mentioned in the video?

The video mentions Compact Disc Read-Only (CD-R), Compact Disk Read-Write (CD-RW), Digital Versatile Disk Read-Only (DVD-R), Digital Versatile Disk Read-Write (DVD-RW), and Blu-ray as the different types of optical storage devices.

How do optical drives read data from a CD-R?

Optical drives read data from a CD-R by shining a laser at the media and processing the reflection. The surface of the disk is physically burnt by the laser, creating pits and lands which represent zeros and ones.

What is the advantage of DVD-RW over CD-RW for backup?

DVD-RW has a greater storage capacity than CD-RW, making it a more useful backup option.

Why did Blu-ray become popular?

Blu-ray became popular as it was designed to supersede DVD and has the greatest storage capacity of all the mentioned optical storage devices, which was necessary for the storage of high-definition motion pictures.

How do magnetic hard disks store data?

Magnetic hard disks store data using a north or south polarity, which is ideal for representing zeros and ones. The technology has been refined to pack more magnetized compounds in the same space, increasing storage capacity.

What is the main drawback of magnetic tapes for data storage?

Magnetic tapes can only be read and written sequentially from start to finish, which makes them slow compared to alternatives and impacts how data can be stored on these devices.

What are the characteristics of solid-state drives (SSDs) mentioned in the video?

Solid-state drives are small, lightweight, quick to access data, operate without noise, and have a limited lifespan due to a limited number of read-write cycles.

Why might a helmet-mounted camera be best suited for a solid-state drive?

A helmet-mounted camera requires high portability, quick data access, durability, and reliability, which are characteristics that solid-state drives possess.

What type of storage would be best for a desktop computer in an office setting according to the video?

For a desktop computer in an office, magnetic media is best for the main hard disk due to its high storage capacity and cost-effectiveness, though a smaller solid-state drive could be used for faster access to the operating system.

In what scenario might cloud-based storage be a good solution?

Cloud-based storage is a good solution for distributing video games for consoles, as it allows for direct download or streaming to the console's hard drive after purchase, and it keeps costs down.

Why is solid-state storage likely the best option for a portable music player?

Solid-state storage is likely the best option for a portable music player because it offers portability, quick file access, durability, reliability, and is relatively low cost given the storage requirements for music files.

Outlines

00:00

💿 Optical and Magnetic Storage Devices

This paragraph discusses various storage devices, focusing on optical storage like CDs, DVDs, and Blu-ray. It explains how these devices work using a laser to read and write data by creating pits and lands on the disk's surface. The paragraph also covers magnetic storage devices, such as hard disks and tapes, and their methods of data storage. The advantages and disadvantages of optical media are highlighted, including its portability, susceptibility to scratches, and the sequential access limitation of magnetic tapes. The summary also touches on the evolution of storage devices in the music and film industry.

05:01

📀 Storage Scenarios and Media Selection

The second paragraph explores different storage scenarios and the selection of appropriate media for each. It discusses the use of solid-state drives (SSDs) for their speed and durability, especially suitable for devices like helmet-mounted cameras. For high-capacity storage with less emphasis on portability, such as in an office setting, magnetic media is recommended. The paragraph also considers the backup requirements of a travel agent, suggesting magnetic media or tapes due to their reliability and cost-effectiveness. It contrasts this with the need for portable and durable storage for students, where USB memory sticks or cloud storage are ideal. The distribution of video games is also examined, with optical media being a cost-effective choice despite the rise of cloud-based solutions.

10:02

🎧 Storage for Music and Video Game Distribution

The final paragraph delves into specific use cases, such as listening to music on portable devices and distributing video games. It suggests that solid-state storage is ideal for music players due to their portability, quick access to files, and durability, despite the higher cost. The paragraph also considers the distribution of video games, where optical media remains a viable option due to its portability and durability, even though cloud-based distribution is becoming more prevalent. The discussion also touches on the long-term storage of training videos, noting that the choice between optical and magnetic media depends on the size of the videos and how they will be accessed.

Keywords

💡Magnetic Storage

Magnetic storage refers to the use of magnetic materials to store data. In the context of the video, it is exemplified by hard disk drives (HDDs) that use magnetic disks to store data. The video explains that magnetic storage is characterized by high capacity and relatively low cost per byte, making it suitable for applications requiring large storage solutions, such as in an office desktop computer scenario.

💡Flash Storage

Flash storage is a type of non-volatile storage that does not require power to retain data. The video mentions solid-state drives (SSDs) as an example of flash storage, highlighting their advantages such as small size, lightweight, quick data access, and silent operation. Flash storage is suggested as an ideal choice for portable devices like helmet-mounted cameras due to its durability and high portability.

💡Optical Storage

Optical storage involves the use of laser light to read and write data on a physical medium, such as CDs, DVDs, and Blu-ray discs. The video script explains how optical drives work by shining a laser at the media and processing the reflection to interpret data. Optical storage is noted for its affordability and portability, with examples including music distribution on CDs and movie storage on DVDs.

💡Drive

A 'drive' in the video script refers to the device that reads and writes data from secondary storage. It is the component that interfaces with the storage media. The term is central to understanding how data is accessed and manipulated, with examples including optical drives for CDs/DVDs and hard disk drives for magnetic storage.

💡Media

Media, as used in the video, refers to the physical material on which data is stored, such as the discs in optical storage or the platters in HDDs. The script discusses various types of media, emphasizing how the choice of media can affect data storage and retrieval, with different media types being suited to different applications.

💡Pits and Lands

Pits and lands are the physical features on an optical disc that represent data. The video describes how a laser burns these features onto the disc to create a pattern of pits (non-reflective areas) and lands (reflective areas), which are read as binary data (zeros and ones). This concept is crucial to understanding how data is physically stored on optical media.

💡Read-Only

Read-only media, such as CD-ROMs or DVD-ROMs, are mentioned in the script as storage that can only be read and not altered. Once data is written to these media, it cannot be changed, which is useful for distributing software or content that should not be modified, like game installations from a DVD.

💡Writeable

Writeable media, like CD-RWs and DVD-RWs, are discussed in the video as storage that allows data to be written and rewritten multiple times. This feature is important for backup scenarios where data might need to be updated or replaced over time, such as using DVD-RWs for backups in a travel agent's office.

💡Portable

The term 'portable' is used throughout the script to describe storage devices that are easily moved from one location to another. This attribute is crucial for applications like transferring data between home and school or capturing video with a helmet-mounted camera, where the device's mobility is a key consideration.

💡Durability

Durability refers to the ability of a storage device to withstand physical stress or damage over time. The video highlights the importance of durability for devices like helmet-mounted cameras that may receive knocks and bumps, and for backup solutions that need to maintain data integrity over long periods.

💡Cloud Storage

Cloud storage is mentioned as a modern alternative to physical media, allowing data to be stored and accessed over the internet. The video suggests that cloud storage is becoming increasingly common for scenarios like game distribution, where users can download games directly to their consoles, bypassing the need for physical media.

Highlights

Optical storage devices are read and written by an optical drive and the data is stored on media.

Compact Discs (CDs) are popular for storing and distributing music.

Digital Versatile Disks (DVDs) are used for storing motion pictures and movies.

Blu-ray disks were designed to supersede DVDs and have the greatest storage capacity.

Optical drives work by shining a laser at the media and processing the reflection.

Writable optical drives use a reversible chemical reaction to change the data.

Optical media is cheap to produce, lightweight, and highly portable.

Magnetic media, such as hard disks, uses magnetized compounds to store data.

Hard disks have a drive head that physically moves over the disk surface.

Magnetic tapes were popular for backups due to their large capacity and portability.

Solid state drives (SSDs) are gaining popularity due to their small size, quick data access, and silent operation.

SSDs use a flow of electricity to store data in floating gates.

SSDs have a limited lifespan due to the deterioration of oxide layers over time.

Choosing the right storage device depends on factors like capacity, speed, portability, durability, and cost.

For a helmet-mounted camera, a solid state drive is the best fit due to its portability and durability.

In an office setting, magnetic media is suitable for high storage capacity and low cost.

For backing up data in a travel agent, magnetic media or tapes are ideal due to their portability and reliability.

Portable USB memory sticks are a simple solution for transferring work between home and school.

Optical media is a good choice for distributing video games due to its portability and durability.

Cloud-based storage is an increasingly common option for distributing and accessing large files.

For long-term storage of training videos, the choice between optical and magnetic media depends on the file size and usage.

For portable music players, solid state storage is ideal due to its portability, quick access, and durability.

Transcripts

in this video we look at the uses of

magnetic

flash and optical storage devices

[Music]

the device that reads and writes data

from secondary storage is generally

referred to

as the drive

what the data is actually stored on is

referred to as

the media

let's start by looking at optical

storage devices

so in the case of optical storage we

have an optical drive

and a choice of media which includes

compact disc read-only or cdr

compact disk read write or cdrw

digital versatile disk read only or

dvd-r

digital versatile disk read write or

dvd-rw

and blu-ray which was designed to

supersede dvd

and has the greatest storage capacity of

all the ones mentioned

as a general rule cdrs became popular

for storing and distributing music and

cd read writes

rws as a backup option

dvd-r became popular for storing motion

pictures and movies

and dvd-rw as a more useful backup

option

as it had greater storage than compact

disks

with development of high definition

motion pictures greater storage was

required

and blu-ray became popular as an

alternative to the digital versatile

disk

the field of music and film storage has

seen many drives and media come and go

over the years

but these are devices that have become

most popular

all optical drives work by shining a

laser at the media

and processing the reflection from the

media

in the case of read-only drives so cdrs

and dvd-rs

the surface of the disk is physically

burnt by the laser

creating what are known as pits and

lands

suitable for storing zeros and ones

more accurately it's the point where the

pit starts or ends

which causes the laser light to scatter

and thus is not reflected as well

it's this change of reflective and

non-reflective areas

which is red and interpreted as the

zeros and ones

clearly once the surface has been burnt

it cannot be changed

making the media read only

it's possible to press optical disks

many thousands of times

and it makes distribution very easy

for example in the past when a popular

artist released new album

or a new film became available for him

viewing the demand was likely to be high

in the case of writable drives cdrws and

dvd-rws

the chemical composition of the disk is

changed

by a reversible chemical reaction this

means the data can be written many times

there are many positives as optical as a

storage media including being cheap to

produce

lightweight and highly portable

dvds store more data than cds because

the pits and lands are smaller and

closer together

as the laser technology has increased

the precision

data is read and written from the inside

of the disk to the outside in a spiral

this can make them slow devices for

accessing data

and optical media is also prone to

scratches

let's now have a look at magnetic media

most hard disks in typical computer

systems use

magnetic disks

imagine a typical magnet it has a north

or south polarity

this is ideal for storing zeros and ones

over the years the technology has been

refined significantly

to pack an ever increasing number of

magnetized compounds

in the same space as a result

magnetic hard disks today have an

extremely high capacity

hard disks have a drive head that has to

physically move

over the surface of the disk

this is the clicking sound you can hear

from your computer

the drive head makes the drive a little

slower than dries with no moving parts

and because this is a mechanical

component it will eventually

fail

tapes have also been popular magnetic

devices in the past

they used to be considered extremely

large in capacity and therefore were

ideal for backups

due to their small size and portability

keeping an offsite backup

was easy with magnetic tapes

unfortunately because they can only be

read and written sequentially from start

to finish

this impacted significantly on how data

could be stored on these devices

they are extremely slow in comparison to

alternatives

they've been largely superseded by

portable hard disks

and cloud storage

solid state drives are gaining in

popularity being small

lightweight and very quick to access

data

they also operate without noise there

are many different types of solid-state

storage

and they're beginning to replace hard

disks as their capacity increases

and their cost decreases

solid state drives work by a flow of

electricity

forcing electrons into floating gates

between

two oxide layers

this causes a change in the charge in

the floating gate

and this can be measured as a zero or a

one

over time the oxide layers deteriorate

meaning that eventually the transfer of

electrons will become

unreliable

this means that solid state media has a

limited number

of read write cycles and therefore a

limited life span

as well as being able to understand and

discuss various types of storage

it's important also to be able to

justify

what type of storage you would use for a

given application

situation or scenario so let's have a

look at a few scenarios now

let's now take a look at a range of

devices and storage scenarios

so here we have a helmet mounted camera

in terms of capacity we want to be able

to store video footage

we want to be able to quickly get the

data on and off the media

and it needs to be stored quickly as

we'll be capturing real-time video

footage

the device needs to be portable and it

needs to be durable

as will potentially receive lots of

knocks and bumps

it needs to be fairly reliable but we

appreciate that over time we'll need to

replace it

given all the options the best fit here

would be a solid state drive

in the snow of a desktop computer in an

office

we have a need for high storage data

capacity

as we'll have lots of programs and user

data

we need to be able to access these

programs and the data reasonably quickly

but portability is less of a concern as

is durability

as the computer is going to be in one

fixed place on the office desk

and isn't going to be moved around very

often

it needs to be fairly reliable and the

cost needs to be quite low

bite for byte because of the significant

data storage requirements

therefore the best fit here is magnetic

media

for the main hard disk but we could also

consider

installing a smaller solid state drive

just to make the computer a little

faster

when accessing the operating system

in case of backing up 800 gigabyte of

data in a travel agent

we've got medium to high data storage

requirements

it doesn't need to be quick but it would

be ideal if it was portable

so we could take the backup off-site

it needs to be fairly durable and as a

backup device

it needs to be very reliable we also

want a medium cost solution here

there are a number of solutions optical

media probably wouldn't be sufficient

because the data capacity requirements

solid state would be quite an expensive

option given the amount of storage

needed

so magnetic media would probably be the

best

we could use tape which would be small

and also be highly portable

transferring work between home and

school is quite a common requirement

and portable usb memory sticks are a

simple and easy solution

here so we're talking about solid state

storage

as they need to have a reasonable amount

of storage they need to be highly

portable

durable and reliable on top of this they

need to be low cost

as the light to be purchased by students

a more modern solution and becoming more

common

would be the ability to access your

files over the internet

using a range of cloud-based server

options

in terms of distributing a video game

for consoles

we have a number of options here we

could use optical media

because the capacity is reasonably small

though this is certainly changing with

some modern graphic intensive games

it doesn't need to be very fast because

the consoles will typically install the

software

off the optical device onto their own

hard drive

it does need to be portable as you're

likely to buy the game from a shop

or order it and have it delivered and it

needs to be fairly durable

and reliable but not overly as once you

have it installed

there won't be much regular further use

for the physical optical disk

you'll also want to keep the cost down

all of these factors make

optical media an excellent choice here

on a dvd you'll get 4.7 gigabyte of

available storage

and this should be sufficient for your

average compressed game another option

and again increasingly common is to use

cloud-based storage

and to have the game streamed and

downloaded directly to your console's

hard drive

after you've purchased them from an

online store

long-term storage of training videos

really depends on how

big those videos are and how they're

going to be used and accessed

it could be that if the training videos

are quite small and you want to

distribute them

using optical media to distribute them

is fine

it could also be that due to the size of

the training videos

the magnetic media of solid state is

your only option

with this scenario more information

would be needed so you fully understood

exactly how the training videos were

intending to be used

finally let's consider listening to

music on a portable music player

here we've got sound files which are not

that large

we do need the device to be portable we

need to be able to access the files

quickly

and we need to have the device being

durable reliable

and ideally low cost so here the best

option is probably

solid state storage although it's more

expensive

bite for bite than magnetic it wouldn't

be significantly expensive given the

amount of storage we'll want

the requirements for portability

reliability

and durability outweigh all the other

considerations

in this scenario so having watched this

video you should be able to answer the

following key question how are

input output and storage devices used in

typical applications of computer science

you