Character coding schemes

Question 1

How many different patterns do we need to represent all the characters on a computer keyboard?

Answer 1

approximately 120

Question 2

How many bits do we need to give us that number of patterns?

Answer 2

7

Question 3

How many bits are used in the ASCII coding scheme?

Answer 3

7

Question 4

How many bits are used in Extended ASCII?

How many characters can be encoded?

Answer 4

8

Question 5

How many bits are used in Unicode?

Answer 5

16

Question 6

How many different characters can be represented using Unicode?

Answer 6

2^16

Question 7

Explain why EBCDIC is not as programmer friendly as ASCII

Answer 7

Because the values assigned to sequential assignment of values in binary.
Operations converting uppercase to lower case is easy in ASCII but not easy in EBCDIC.

Question 8

How many different character codes can be represented using 7-bit ASCII?

Answer 8

128

Question 9

Describe what is meant by a character set

Answer 9

Number of characters that can be accepted by a computer system.

Question 10

Explain why mobile phones that can send emoji would use Unicode instead of ASCII as their character set

Answer 10

Not enough bits in ASCII

Question 11

Explain two differences between Unicode and ASCII

Answer 11

Unicode and ASCII use different number of bits.
ASCII for standard characters
Unicode - many languages

Question 12

Explain what is common in Unicode and ASCII

Answer 12

The first byte uses the same characters

Question 13

State one advantage of using Unicode instead of ASCII

Answer 13

Store more characters, multiple languages 2^16

Question 14

State one advantages of using Unicode instead of ASCII

Answer 14

More memory used for each character