Finite state machines may sound like a very dry and boring topic but they reveal a lot about the power of different types of computing machine.  Every Turing machine includes a finite state machine so there is a sense in which they come first. They also turn out to be very useful in practice.

Inconvenient though they may be, fractions are the real stuff of numbers and to work with them we need to know about floating point numbers ...

What are objects really all about? The data stupid. We don't give data enough credit for it role in programming. Perhaps we shouldn't call it coding but datering or something. The relationship between data and code is deep and it is the real reason we invented object oriented programming.

How does a hard disk work? Understanding can help you pick your next drive and make you more aware of what can go wrong.

Although it is a matter of opinion, you can't help but admire the idea of the hash function. It not only solves one of the basic problems of computing - finding something that you have stored somewhere - but it helps with detecting file tampering, password security and more.

Hexadecimal is the most common way of displaying the raw data sitting in a machine's memory, but if you are not familiar with it you might ask "What the hex..?"

Exactly how does computer memory work? What is surprising is that  it still works in more or less the same way as when Babbage designed his Analytical Engine or the IBM 360 accessed core memory. So where do all our programs live?

Bitcoin is a currency that exists entirely in software and is under the control of no central authority. What is really important about Bitcoin, however, are the algorithms that make it all work. We explain the way the Block Chain works. 

We often refer to things that are unpredictable as being "random" but this is not the same as truly random behavior - which is something we have to work hard to achieve. Put another way - how can a logical deterministic device like a computer produce a random number?

Where you store data is as important to the computer as the data itself, yet the importance of the address is often overlooked. In this introduction to the low-level mechanisms of addressing in assembler, it is surprising how easy it is to recognize familiar high-level abstractions.

It may sound like a daunting topic, but Boolean logic is very easy to explain and to understand. It represents the simplest of all the logics and the very basis of computing.

Genetic algorithms pop up all over computer science and applied computing. They are simple, easy to apply and easy to understand. What mystery remains is why they work at all? How can something seemingly so random home in on a one in a million plus solution? 

Every programmer should understand how the Internet works and this means understanding IP addressing and routing. It's a good time to find out about such things with DOS attacks on the rise and IPv6 taking over from IPv4.

This xkcd cartoon provides an ideal excuse to explain Kolmogorov complexity. It is an interesting topic and one that gets right to the heart of programming of how programming relates to ideas like information and entropy. This is a subject that still has lots of mysterious connections with things outside of computing.

The merge sort is an under-appreciated algorithm - yet it is neat, clever and it still has its uses. With the rise of big data, parallel methods and online processing, you can even argue that it is growing in importance. Let's take a look at how it works and when you should use it. 

We are being offered ever more cores within a single processor as if this was as good as making the machine go faster. What exactly is the change from single to multi-core all about?

We take multitasking for granted now but it was a difficult technology to get right - and still is. We take a look at how it all developed and at the variations on the basic idea.