The smallest item of data that a computer can store is called a bit, a single one or zero. One bit is too small to be of practical use.

Eeight bits make one byte.

1024 bytes make one kilobyte (Kb).

1024 kilobytes make one megabyte (Mb).

1024 megabytes make one gigabyte (Gb).

1024 gigabytes make one terabyte (Tb).

Answer the following questions in your jotter.

1. Write typical capacities for the following backing storage devices:

(a) Floppy Disk
(b) CD
(c) DVD
(d) Hard disk
(e) Magnetic Tape
(f) Zip disk
(g) Compact Flash Card / Multimedia Card / Memory Stick

Use the answers above to answer the questions below.

2. How many floppy disks are equivalent to one CD?

3. How many CDs are equivalent to one DVD?

4. How many CDs would be needed to back up a hard disk of the capacity mentioned in Q1(d)

Use the Internet to answer the following questions.

5. Information on a magnetic tape can only be accessed sequentially. What does this mean?

6. Information on other forms of backing storage can be accessed randomly. What does this mean?

7. Some forms of backing storage are optical and some are magnetic. Which of the devices mentioned above are optical and which are magnetic devices?

8. How is information stored and accessed on an optical backing storage device?

9. How is information stored and accessed on a magnetic backing storage device?

10. Describe the different ways of recording information on a CD-R and a CD-RW.

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