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Convert denary to binary
Divide by 2 for x remainder y. Write y in place value and divide x by 2 again. Repeat
Convert denary to hex
Divide by 16 for x remainder y. Write y in hex form in place value and divide x by 16 again. Repeat
What is a bit?
A single 0 or 1
What is a nibble?
4 bits (1010)
What is a byte?
8 bits (10101010) / 2 nibbles
Hex to binary
Map values one digit at a time
Binary to hex
Map values one nibble at a time
Why use hexadecimal?
less display space needed; faster to enter data; easy to convert back to binary; easier to identify values and spot errors
Example usages of hex
Colour coding when formatting web pages in HTML or CSS; low-level code; addresses; error messaging
What indicates that a colour is being coded in hex?
#
How do hex colour codes work?
2 hex digits for each of RGB
White in hex
FFFFFF
Red in hex
FF0000
Black in hex
000000
What does the value of the hex numbers represent?
Intensity of colour
When might you see hex options when setting colour values?
Graphics packages e.g. Adobe creative suite apps
How are hex colour codes used in laser cutters?
Identify how to set laser strength and depth of cut
Why is hex used in assembly code?
Quicker, easier and less error prone for programmers to type assembly code values in hex than long binary strings
How do programmers make it more efficient to troubleshoot low level code?
Using hexadecimal instead of typing out long binary strings
How is hex used in addresses?
Both IP and MAC addresses
What do MAC addresses do?
Media access control - uniquely identify devices on a network
Where do devices get their MAC addresses from?
Assigned by device manufacturer
What are MAC addresses made of?
6 pairs of hex digits NN-NN-NN-DD-DD-DD
What is the NN-NN-NN in MAC addresses
ID of manufacturer
What is the DD-DD-DD in MAC addresses
serial number of device
Which comes first in a MAC address - NN-NN-NN or DD-DD-DD
NN-NN-NN
What do IP addresses do?
Internet Protocol - identify where a device is on a network
What number system are IP version 4 addresses?
decimal
What are IP version 6 addresses?
hex
Which uses hex - IP version 4 or version 6
Version 6
What does IPv6 do?
Provides enough unique addresses for every networked device on the planet
How are IPv6 addresses organised?
128 bits; digits organised in 8 groups; 4 hex digits per group
How many bits in an IPv6 address?
128
Where is hex used in error messaging?
Display of error codes in embedded systems e.g. lifts
Why are hex codes used in error messaging?
Embedded systems have tiny screens if any; hex takes up less space than binary
