1.4.1 Data Types

Question 1

1.4.1 A)
What is the need for data types

Answer 1

Data stores in binary stored in right data type so right operations can be preformed

Question 2

5 data types with brief expiation

Answer 2

Integer - whole number
real / float - decimal point number
character- single symbol
string - collection of character
Boolean - True or False

Question 3

1.4.1 B)
Whats a single binary digit called
8 bits
4 bits

Answer 3

bit
1 byte
1 nibble

Question 4

Bases for binary, decimal , hexadecimal

Answer 4

2 , 10 ,16

Question 5

1.4.1 C)
What is sign and magnitude

Answer 5

Leading 1 = negative
Leading 0 = positive
Example binary 173 10101101
sign and magnitude +173 010101101
sign and magnitude -173 110101101

Question 6

Twos complement

Answer 6

flip +1

Question 7

1.4.1 D)
adding and subtracting

Answer 7

0 + 0 = 0
1 + 0 = 1
1 + 1 = 10
1 + 1 + 1 = 11

1 = 2 on coluemm to the right

Question 8

1.4.1 E/F)
Hexadecimal conversion

Answer 8

Hex 0-9 = 0-9
10-15 = A-F
base 16
split into digit convert hex into dec
convert dec > binary
combine nibbles

Question 9

1.4.1 g)
normalisation

Answer 9

must start with 10 or 01 (shift the exponents and mantissa )

Question 10

floating point

Answer 10

exponent use two complement move decimal point + right - left decimal starts between 1st and 2nd digit in mantissa

Question 11

(h) Floating point arithmetic, positive and negative
numbers, addition and subtraction.

Answer 11

Too add fp exponent must be the same must normalize

too sub make exponent same (mantissa twos complement > add > normalise

Question 12

(i) Bitwise manipulation and masks: shifts, combining
with AND, OR, and XOR.

Answer 12

Shift right n =2^n increase
Shift left n =-2^n increase

masks can be applied to binary number combined with logic gated
AND 1 + 1 = 1 , 0 + 1 = 0 , 0 + 0 = 0
OR 1 + 1 = 1 , 0 + 1 = 1 , 0 + 0 = 0
XOR 1 + 1 = 0 , 1+0 = 1 , 0 + 0 = 0

Question 13

j) How character sets (ASCII and UNICODE) are used
to represent text

Answer 13

ASCII 7 bits 128 diff char A-Z 65-90 , a-z 97-122
ASCII cant represnt diff languages

unicode solved this problem using varying number of bits allowing over 1m diff char