The Hexadecimal Code
Think of the hexadecimal code as an extended binary code
Binary code is made up of sets of one bit (either 0 or 1) – LED ON or LED OFF
Hexadecimal code is made up of sets of four bits.
In general, computers use Assembly Language to carry out instructions.
Assembly language is virtually written entirely using hexadecimal code.
We can convert each set of four binary bits into a single hexadecimal bit.
This allows for more information to be stored and retrieved more efficiently.
Changing from binary [BASE 2] to hexadecimal [BASE 16] is called a fourbit conversion.
Comparing the number systems
Decimal
 ten possible digits (0 to 9)
Binary
 two possible digits (0 and 1)
Hexadecimal
 sixteen possible digits (0 to 9 + A to F)
Converting BASE 2 to BASE 16
 Divide binary numbers in groups of 4
 Assign the hexadecimal value to each group
 If a group does not have 4 digits add zeros in front of it
Example 1: convert 1000111 into hexadecimal
 First group = 0111

Second group = 0100
(noticed we added a 0 in front of the one)
Group 1
 0111 = 7 (from the chart)
Group 2
 0100 = 4
Therefore 1000111 = 47
Example 2: convert 101110101101 into hexadecimal
1011 1010 1101
 First group = 1101
 Second group = 1010
 Third group = 1011
Group 1
 0111 = “D” (from the chart)
Group 2
 1010 = “A”
Group 3
 1010 = “B”
Therefore:
101110101101 = “BAD” in hexadecimal code