1. Backing Storage Devices

2.  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. Learning Intentions for this Unit of Work

3. Success Criteria  Choose a backing storage devices for a given system or situation and justify my choice.  Show all of my working when performing storage calculations.

4. The Computer System INPUT OUTPUT BACKING STORAGE PROCESSOR MAIN MEMORY WRITEREAD

6. Backing Storage Units  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) KeepMyGardenTidy KilobyteMegabyte Gigabyte Terabyte

7. What are Backing Storage devices?  The Main Memory is used to store our work while the computer is on. When the power is switched off this data is wiped.  Backing Storage devices are used to save our work and programs permanently. Main Memory Hard Disk with case removed

8. Terms you need to know  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.

9. Backing Storage Data Sheet

10. 1. Name the 3 types of backing storage devices 2. Which type of backing storage devices use a laser to read and write data to it? 3. Which type of backing store has no moving parts? 4. Which backing storage device can hold up to 3 Terabytes of data? 5. Which Solid backing storage devices is a read only backing store? 6. Which backing store only allows you to read the data held on it order? 7. Which backing storage device is commonly used to store High Definition videos? 8. Which Solid backing store is commonly found in smartphones and digital cameras? 9. How many Gigabytes are there in 2 Terabytes? HINT 1 Terabyte = 1024 Gb Backing Storage Questions

11. Answers 1. Magnetic, Optical and Solid 2. Optical 3. Solid 4. Hard Disk 5. ROM cartridge 6. Digital Audio Tape 7. Blu Ray 8. SD Memory Card

12. At the computer – www.pcworld.co.uk 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

15. Calculations 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

16. 3. How many bytes in 256 bits?  ANSWER: 256 / 8 = 32 bytes 4. How many bytes in 512 bits?  ANSWER 512/8 = 64 bytes

17. 5. How many Kilobytes in 2048 bytes  ANSWER: 2048 / 1024 = 2 Kb 6. How many Megabytes in 4096 Kilobytes  ANSWER: 4096 / 1024 = 4Mb

18. 5. How many Kilobytes in 2048 bits  ANSWER: 2048 / 1024 = 2 Kb 6. How many Megabytes in 4096 Kilobytes  ANSWER: 4096 / 1024 = 4Mb

19. 7. Calculate the storage required for the top 5 downloaded albums shown: Answer in Megabytes  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 Battle Born350 Mb The Truth about Love 322 Mb Number 3258 Mb Coexist289 Mb Our version of events 317 Mb Top 5 Downloaded Albums

20. 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

21. Converting between units 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

22. 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

23. Answers 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