Binary systems and Hexadecimal

Question 1

What is binary?

Answer 1

• Series of 1’s and 0’s that represent values or characters
• Values are stored in base-2 (denary is in base-10)
• One binary digit is called a ‘bit’
• 8 bits make up one ‘byte’
• The maximum size of the integer able to be stored depends on the number of bits used - e.g. the largest number stored by 8 bits is 255

Question 2

Describe the use of binary in computer registers

Answer 2

• A register is a location where data that the processor is using can be stored
• Processors have internal registers that data can be transferred between
• The register itself is a group of binary cells, where data is stored as a series of 1’s and 0’s.

Question 3

What is binary-coded decimal and where is it used?

Answer 3

• A system of writing numerals where each digit is represented by a 4-bit binary sequence
• Has the advantage that there is no limit to the size of the number: to add another digit, you just need to add a new 4-bit sequence
• Used in barcodes and arithmetic where every digit has to be retained in a result

Question 4

What is hexadecimal?

Answer 4

• Series of the numbers 1-9 and letters A-F that represent values or characters
• Values are stored in base-16

Question 5

Why is hexadecimal used to represent numbers?

Answer 5

• Each hexadecimal digit represents 4 binary digits, so it is shorter to read
• Easier for programmers to read as more characters are used (not just 1’s and 0’s)
• Very large numbers can be stored in a smaller amount of space

Question 6

List some current uses of hexadecimal numbers in computing

Answer 6

• defining colours in Hypertext Markup Language (HTML)
• Media Access Control (MAC) addresses
• assembly languages and machine code
• debugging