Learning Intentions for this Unit of Work




We are learning to:
Make comparisons between different backing
storage devices using their features.
Identify appropriate backing storage devices
for a computer system/situation.
Perform calculations relating to the storage
required for files.


Choose a backing storage devices for
a given system or situation and justify
my choice.
Show all of my working when
performing storage calculations.
The Computer System
MAIN
MEMORY
INPUT
PROCESSOR
WRITE
READ
BACKING
STORAGE
OUTPUT
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
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
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
1 bit – the smallest unit of memory
8 bits = 1 byte
1024 bytes = 1 Kilobyte (Kb)
1024 Kb
= 1 Megabyte (Mb)
1024 Mb = 1 Gigabyte (Gb)
1024 Gb = 1 Terabyte (Tb)
Keep
Kilobyte
My
Garden
Megabyte Gigabyte
Tidy
Terabyte


The Main Memory is
used to store our work
while the computer is on.
When the power is
switched off this data is
wiped.
Main Memory
Backing Storage
devices are used to save
our work and programs
permanently.
Hard Disk with case
removed
ROM – Read Only Memory
 R – Recordable- Record up to the capacity
of the disc
 RW- Rewritable – Write over many times
 RE - Recordable Erasable (for Blu Ray)

Direct – Data can be written and read in
any order
 Sequential- Data can only be read in the
order it was written.

Backing Storage Questions
1.
2.
3.
4.
5.
6.
7.
8.
9.
Name the 3 types of backing storage devices
Which type of backing storage devices use a laser to
read and write data to it?
Which type of backing store has no moving parts?
Which backing storage device can hold up to 3
Terabytes of data?
Which Solid backing storage devices is a read only
backing store?
Which backing store only allows you to read the data
held on it order?
Which backing storage device is commonly used to
store High Definition videos?
Which Solid backing store is commonly found in
smartphones and digital cameras?
How many Gigabytes are there in 2 Terabytes?
HINT 1 Terabyte = 1024 Gb
1.
2.
3.
4.
5.
6.
7.
8.
Magnetic, Optical and Solid
Optical
Solid
Hard Disk
ROM cartridge
Digital Audio Tape
Blu Ray
SD Memory Card
For each of the backing storage devices find the highest capacity
model and note its cost.
Cost per Gigabyte = Cost per item/ Capacity found
Example: ROM Cartridge: 20.00 / 8 = £2.50 per Gigabyte
Round up to the nearest penny
1. 16 bits – What is this in bytes?
 Remember 8 bits = 1 byte
 So 16 /8 = 2 bytes
2. 32 bits – What is this in bytes?
 Remember 8 bits = 1 byte
 32/8 = 4 bytes
3. How many bytes in 256 bits?
 ANSWER: 256 / 8 = 32 bytes
4. How many bytes in 512 bits?
 ANSWER 512/8 = 64 bytes
5. How many Kilobytes in 2048 bytes
 ANSWER: 2048 / 1024 = 2 Kb
6. How many Megabytes in 4096 Kilobytes
 ANSWER: 4096 / 1024 = 4Mb
5. How many Kilobytes in 2048 bits
 ANSWER: 2048 / 1024 = 2 Kb
6. How many Megabytes in 4096 Kilobytes
 ANSWER: 4096 / 1024 = 4Mb
7. Calculate the storage
required for the top 5
downloaded albums shown:
Answer in Megabytes
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
ANSWER:
350 + 322 + 258 +289 +
317 = 1536Mb
8. How many Gigabytes of
storage would the 5 albums
take up?
 ANSWER:
 1536 /1024 = 1.5 Gb
9. Which Optical Backing
Storage medium will be
large enough to hold the 5
albums?
 ANSWER: DVD
Top 5 Downloaded Albums
Battle Born
350 Mb
The Truth
about Love
322 Mb
Number 3
258 Mb
Coexist
289 Mb
Our version
of events
317 Mb
10. How many MP3s could you fit on a
CD-RW (700 Mb) if the average file size was
8 Megabytes?
Show all your working
Answer: CD-RW Capacity = 800Mb
 700/ 8 = 87.5
 So 87 MP3s

Question
Add 1.5 Gb to 256 Mb
How can we do this if the values numbers above use different
units?
First we need to covert 1.5 Gb to Mb.
How many Megabytes in a Gigabyte? 1024Mb
So 1.5 * 1024 = 1536 Mb
Now we can add them up
1536 + 256 = 1792 Mb
What is this in Gigabytes?
1792 / 1024 = 1.75 Gb
Show all of your working for the following
1.
Add 1 Gb to 512 Mb . Answer in Gigabytes
2.
Find the total storage requirements for the
following files:
MP3 = 32 Megabytes
Alton Towers Trip Photo album = 128Mb
HWB- Health lifestyles video = 2 Gb
1.
1 Gb = 1024 Mb
So 1024 + 512 = 1536Mb
1536 / 1024 = 1.5 Gb
2.
2 * 1024 = 2048
So 2048 + 32 +128 = 2208 Mb
2208/1024 = 2.15625
= 2.16 Gb to 2 Decimal places