4 - Data Codes

Question 1

Why use hexadecimal notation?

Answer 1

• Convenient shorthand for binary numbers
• Every hexadecimal digit exactly represents 4 binary bits

Most importantly, memory locations (1 byte, 8 bits) can be described in 2 hex digits, instead of 8 binary digits !

Question 2

1001 1110 (Base 2) in Hexadecimal?

Answer 2

9E_16

Question 3

AA3E in binary?

Answer 3

1010 1010 0011 1110

Question 4

What is a ‘bit’ in the physics sense?

Answer 4

A high or low state of voltage in the CPU.

Higher value of volt is 1 and lower value is 0.

The specific values are different in various logic families and components.

Question 5

How many bits are used in ASCII, EBCDIC and Unicode?

Answer 5

ASCII is 7, EBCDIC 8 and Unicode can be 8, 16 or 32.

Question 6

How would you go from decimal to Hexadecimal ?

Answer 6

Divide by 16.