0

## Still More Quick Snippets

Published on Sunday, June 16, 2013 in , , , , , June's snippets are ready!

This month, we're going to look at computers, and especially the use of hexadecimal notation. It seems scary at first, but with a little understanding, it's easily tamed.

• Regular Grey Matters readers are very familiar with the videos from Numberphile. Here's their excellent introduction to hexadecimal, a system used with computers that help makes software and hardware engineering simpler:

• Speaking of computers and Numberphile, the makers of that channel have a newer video series, dubbed Computerphile. Not surprisingly, it's about all aspects of computers. Below is their newest release, about the early BBC B Microcomputer:

• One thing that often confuses people about hexadecimal is how to quickly recall which letters A through F go with which numbers 10-15. As long as you know that A, B, C, D, E, and F are the 1st, 2nd, 3rd, 4th, 5th, and 6th letters respectively it's actually pretty easy.

For example, what is the equivalent of 13? Simply add the two digits, 1 + 3 = 4, so it must be the 4th letter, which is D! This works for all the digits:

```10 = 1 + 0 = 1 = A
11 = 1 + 1 = 2 = B
12 = 1 + 2 = 3 = C
13 = 1 + 3 = 4 = D
14 = 1 + 4 = 5 = E
15 = 1 + 5 = 6 = F.```
Going from letters to numbers is almost as easy. If you need to recall which letter goes with which number, figure out which letter of the alphabet it is, from 1 to 6, then subtract 1 from that and put a 1 to the left of that number.

For example, what number is the equivalent of E? E is the 5th letter of the alphabet. 5 - 1 = 4, and a 1 placed to the left of that 4 makes 14. Now you can easily recall that E represents 14! With practice, these conversions will become almost automatic.

• One of the most common uses for hexadecimal in computers is to represent colors. Here are the basics of how hexadecimal numbers are used to represent colors. As with hexadecimal itself when you first learn it, it's not intuitive. Fortunately, the good people at stackoverflow.com have shared several excellent ways to develop an intuitive hexadecimal color sense.

• As mentioned in the Numberphile video above, one of the advantages of working with hexadecimal is that it converts so readily to binary when needed. To get a better understanding of this usefulness, Lazaro Diaz of the Networking Doctors shows how to work through this process: