3b - Coding Text

Question 1

What is a parity bit?

Answer 1

A parity bit is an extra bit added to a binary number to ensure that the total number of 1 bits is even or odd.

Question 2

How is a parity bit used during data transmission of a single character?

Answer 2

1. The total number of 1 bits is calculated before transmission.
2. A 0 or 1 bit is added to the 7-bit code.
3. The total number of 1 bits must compute to an even number.
4. The number of 1 bits is re-calculated after received.
5. An odd number of 1 bits indicates an error.

Question 3

Why can’t an 8-bit representation of a number be stored in UNICODE?

Answer 3

UNICODE is 16-bit, so eight extra 0’s will be needed.

Question 4

What is meant by a character code?

Answer 4

A character code uses a unique number/code to represent each different character.

Question 5

How are alphabetic characters represented in a computer system?

Answer 5

Each character is stored as a unique code.

Question 6

What are two differences between Unicode and ASCII?

Answer 6

• Unicode uses more bits for each character
• ASCII uses fewer bits for each character
• Unicode can represent a wider range of characters
• ASCII can represent a smaller range of characters
• Unicode uses 16/32 bits, ASCII uses 7 bits (or 8 bits).

Question 7

What is the key difference between lossless and lossy compression methods?

Answer 7

Lossless compression allows for full recovery of the original data, while lossy compression does not allow for recovery and degrades the data.