Understanding the Wizardry of Technology -
How a Computer Works

It’s not uncommon to get frustrated at your computer; when it seems to take forever to load, when it crashes and doesn’t save your work, or when it loses your internet connection. All these things make the temptation to throw it out the window very strong indeed…

Computers are wonders of technology though, and while they might have their moments, really we should be thankful and amazed that they ever work at all. These are simple looking devices – often small enough to fit in a satchel – that are capable of playing photorealistic computer games and of giving us access to all the world’s information. That’s pretty incredible when you think about it.

The problem is that normally we don’t think about it. Usually we’re quite content to let our computers do their thing without ever asking what’s actually going on under the hood and that’s why it can be easy to take them for granted.

Read on and we’ll look at the amazing logic and intricate machinery that underpins everything you do on your computer…

It’s All About Switches

The first thing you need to know about the way your computer works, is that it essentially boils down to switches. More specifically, your processor – which is the ‘brain’ of your PC – is made up of around 10 million tiny ‘transistors’ which are tiny semiconductors which can be used to control the flow of electricity… switches.

At any one time, these switches can control the direction of a current and thereby result in billions of potential combinations. These combinations in turn are what are responsible for all the different possible outputs of your computer.

Introducing Logic Gates

How do switches result in your computer being able to do math or tell you when you have an appointment, though? Well, that comes down to what are known as ‘logic gates’, which are combinations of switches arranged in a specific way. These logic gates allow us to represent conditions like ‘AND’, ‘OR’, ‘IF’ and ‘THEN’ and thereby get our computers to solve a range of problems.

The best way to visualize this is to imagine the kind of circuit you might have made in school with a battery connected to an LED via two wires and a switch in the middle.

That basic circuit is also an ‘IF’ statement.

Why? Because you can ask the circuit a question structured in that way: ‘IF a, THEN b’. In other words, ‘IF the switch is turned on, THEN light up the LED’.

An ‘OR’ gate meanwhile would look like two switches next to each other on parallel wires, both connected to the circuit. In this case you can say that the wire is on if either switch a OR switch b is in the ‘on’ position.

To create an ‘AND’ gate, you would have two switches in sequence on the same circuit. Now you need switch a AND switch b to be on in order for the light to show.

By combining millions of these combinations, it is then possible for a computer to answer countless ‘questions’ that can represent all kinds of higher level problems.

Binary and Abstraction

‘Binary’ is the name for the countless 0s and 1s you often see in films to represent computer code. What’s interesting about these 0s and 1s is that they can easily and directly be related back to what’s physically happening inside the computer. Here a ‘0’ simply means ‘off’ and a ‘1’ means ‘on’. Alternatively, they can be interpreted as ‘charge’ and ‘no charge’, respectively.

Now of course it would drive you absolutely mad to try and instruct a computer purely using binary, which is why sequences (arrangements of switches) are used to ‘translate’ those 0s and 1s into more recognizable ‘machine code’. On top of this, programs can be used to make more sense of that with more and more layers making code sound more and more like English. This is what is known as ‘abstraction’. Ultimately, writing code often means literally writing ‘IF this, THEN that’.

There’s much more to computers than that though and we’ve really only scratched the surface of all the amazing things they do and the incredible ways they work. Did you know, for instance, that transistors wouldn’t even exist if it wasn’t for quantum physics? A branch of science so complicated that it predicts that molecules can exist in two places at the same time?

It would take an entire tome to go through all the miraculous workings of your computer but here’s one more fact that you maybe didn’t know. You see that off button on your PC? The little circle with a vertical line through it? That’s actually binary: a zero and a one, or on and off! So there you go, maybe you can read a little binary after all…