10. OCR A Level (H046-H446) SLR3 - 1.1 Magnetic, flash and optical storage
Summary
TLDRThis 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
- ๐ฟ 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.
- ๐ 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.
- ๐งฒ 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.
- ๐ 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.
- ๐ซ 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.
- ๐ The lifespan of SSDs is limited by the number of read/write cycles due to the deterioration of oxide layers over time.
- ๐ผ 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.
- ๐ฅ 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.
- ๐ For backup purposes, especially when portability and medium cost are concerns, magnetic media like external hard drives or tapes can be a suitable choice.
- ๐ฎ 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.
- ๐ต 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
๐ฟ 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.
๐ 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.
๐ง 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.
Mindmap
Keywords
๐กMagnetic Storage
๐กFlash Storage
๐กOptical Storage
๐กDrive
๐กMedia
๐กPits and Lands
๐กRead-Only
๐กWriteable
๐กPortable
๐กDurability
๐กCloud Storage
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
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