{"id":4845,"date":"2019-12-18T12:51:48","date_gmt":"2019-12-18T12:51:48","guid":{"rendered":"http:\/\/davidwithington.com\/?p=4845"},"modified":"2019-12-18T12:51:48","modified_gmt":"2019-12-18T12:51:48","slug":"how-computers-talk","status":"publish","type":"post","link":"https:\/\/davidwithington.com\/how-computers-talk\/","title":{"rendered":"How Computers Talk"},"content":{"rendered":"

\"How<\/a><\/p>\n

Forget all that TCP\/IP stuff. Let’s get really basic.<\/span><\/p>\n

How do computers talk?\u00a0<\/span><\/p>\n

They talk with digits.<\/span><\/p>\n

And that’s why it’s known as digital<\/em>.<\/span><\/p>\n

\"Computers<\/a>
Computers speak digitally<\/figcaption><\/figure>\n

How Do Computers Talk?<\/span><\/h2>\n

In this article, I’m going to explain how this talking<\/em> works.<\/span><\/p>\n

I’ll take what some might regard as complex, and make it as simple as I can.<\/span><\/p>\n

But don’t worry if you don’t get it straight away. Jump right to the conclusion and it’ll all make sense.<\/span><\/p>\n

What’s Digital?<\/span><\/h2>\n

Digital is lots of ones and noughts.<\/span><\/p>\n

Yes, the good old fashioned number 1. And the number 0.<\/span><\/p>\n

1 is ‘on’.<\/span><\/p>\n

So guess what 0 is.<\/span><\/p>\n

Correct. It’s ‘off’. Go to the top of the class.<\/span><\/p>\n

And all those strings of ones and noughts is known as binary<\/strong>.<\/span><\/p>\n

\"Computers<\/a>
Computers speak in binary code<\/figcaption><\/figure>\n

Remember that word binary<\/em>, ‘cos it’s important.<\/span><\/p>\n

It looks something like this:<\/span><\/p>\n

100110001111101110011000<\/span><\/p>\n

Does that look like gobbledegook?<\/span><\/p>\n

If you were a computer, you’d understand it. <\/span><\/p>\n

But because you’re a human, it looks a bit gobbledegook. <\/span><\/p>\n

Fortunately,\u00a0 we can change it into a more readable format for us humans.<\/span><\/p>\n

\"How<\/a>
How can humans understand computer-speak?<\/figcaption><\/figure>\n

Digital That Humans Can Understand<\/span><\/h2>\n

Everything on a computer is given a value.<\/span><\/p>\n

Let’s take colours, for example.<\/span><\/p>\n

At some time in your life, I bet you’ve seen colours expressed as values such as<\/span><\/p>\n

#00ff00<\/strong> or #98fb98<\/strong><\/span><\/p>\n

Those are green<\/span><\/strong><\/span> and pale green<\/span><\/strong><\/span>, by the way.<\/span><\/p>\n

That’s simply our human way of interpreting binary. <\/span><\/p>\n

And that way is called hexadecimal<\/strong>.<\/span><\/p>\n

\"Pale<\/a>
Pale green and its hexadecimal value – photo credit: spycolor.com<\/figcaption><\/figure>\n

That pale green<\/em> colour you saw just above, by the way… t<\/span>he #98fb98 one…<\/span><\/p>\n

That has a binary<\/em> value of 100110001111101110011000.<\/span><\/p>\n

Why Do We Need Binary and Hexadecimal?<\/span><\/h2>\n

Because computers understand binary. <\/span><\/p>\n

You know… the ‘on-off-on-off’ ones and noughts<\/em> language.<\/span><\/p>\n

But so that humans can understand that computer-speak, we display it as hexadecimal.<\/span><\/p>\n

I’d hate to have to read all those ones and noughts, wouldn’t you?<\/span><\/p>\n

But I can just about manage something like 98fb98.<\/span><\/p>\n

\"I<\/a>
I can manage just a bit<\/em> of hexadecimal<\/figcaption><\/figure>\n

Getting from Hexadecimal to Binary<\/span><\/h2>\n

It might be hard to imagine how 98fb98<\/strong> and 100110001111101110011000<\/strong> can be the same.<\/span><\/p>\n

But they are.<\/span><\/p>\n

Here’s the slightly techie bit. <\/span>So go and make yourself a brew first.<\/span><\/p>\n

Binary<\/em> is to base 2<\/strong>.<\/span><\/p>\n

What does that mean, David?\u00a0<\/span><\/p>\n

It means that 1 is 1.<\/span><\/p>\n

OK. I get that.<\/span><\/p><\/blockquote>\n

But when you get to 2, it’s shown as 10.\u00a0<\/span><\/p>\n

Uh?<\/span><\/p><\/blockquote>\n

Let’s compare it with something we use every day: our beloved decimal<\/em> counting system.<\/span><\/p>\n

\"The<\/a>
The good old familiar decimal numbers<\/figcaption><\/figure>\n

Decimal<\/em> is to base 10<\/strong>.<\/span><\/p>\n

That means that when we get to 10, we show it as 10.<\/span><\/p>\n

In other words: we count up to 9, and then the next number is a one<\/em> and a nought<\/em>.<\/span><\/p>\n

Similarly, with binary<\/em>, we count up to 1. And the next number is a one<\/em> and a nought<\/em>.<\/span><\/p>\n

Still with me?<\/span><\/p>\n

No? <\/span><\/p>\n

Don’t worry. Go back and read those last few lines, and then we’ll move on.\u00a0<\/span><\/p>\n

You’ll get it. It’ll make sense.<\/span><\/p>\n

Here’s a little table showing a few decimal numbers and their binary equivalents. <\/span><\/p>\n

See if you can work it out.<\/span><\/p>\n\n\n\n\n\n\n\n\n\n\n
Decimal (base 10)<\/td>\nBinary (base 2)<\/td>\n<\/tr>\n
0<\/td>\n0<\/td>\n<\/tr>\n
1<\/td>\n1<\/td>\n<\/tr>\n
2<\/td>\n10<\/td>\n<\/tr>\n
3<\/td>\n11<\/td>\n<\/tr>\n
4<\/td>\n100<\/td>\n<\/tr>\n
8<\/td>\n1000<\/td>\n<\/tr>\n
9<\/td>\n1001<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

An Easier Way to See Binary<\/span><\/h2>\n

If you’re still not quite with me, here’s another way of looking at it.<\/span><\/p>\n

My wife got it when I showed her this, so take heart.<\/span><\/p>\n

Let’s take, as an example, the decimal number 13<\/strong>.<\/span><\/p>\n

It’s made up of an 8<\/strong>, a 4<\/strong> and a 1<\/strong>.\u00a0<\/span><\/p>\n

So it’ll look like this…<\/span><\/p>\n\n\n\n\n\n
Binary Value<\/span><\/td>\n<\/td>\n8<\/span><\/td>\n4<\/span><\/td>\n2<\/span><\/td>\n1<\/span><\/td>\n<\/tr>\n
Digits<\/span><\/td>\n<\/td>\n1<\/span><\/td>\n1<\/span><\/td>\n0<\/span><\/td>\n1<\/span><\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Can you see how a decimal 13<\/strong> becomes 1101<\/strong> in binary? <\/span><\/p>\n

Binary and Decimal<\/span><\/h2>\n

“So why doesn’t a computer convert binary to decimal for us humans?” I hear you ask.<\/span><\/p>\n

It does when it’s spewing out the final product.<\/span><\/p>\n

That’s nice and clear. <\/span><\/p>\n

It even produces a nice page full of…<\/span><\/p>\n