December 5, 2013

Bytes and bigger

Advent Computing: Bytes and bigger

We now know a single “1” or “0” is called a bit, and eight of them is a byte, the standard unit most computers use for handling numbers. But that’s not actually true. Or at least it’s an over-simplification. See, our Turing machine only ever...

December 4, 2013

More things with numbers

Advent Computing: More things with numbers

The last two posts have been about how a computer converts between the numbers it stores and letters and symbols you see on your screen or out of your printer. But computers don’t just use numbers for storing text. Computers use numbers for everything. One...

December 3, 2013

More bits

Advent Computing: More bits

Yesterday I talked about encoding characters, i.e. letters and numbers and symbols, in bytes. One byte can represent any number between 0 and 255, and the near-universal standard known as ASCII gives a specific character for any number between 0 and 127. If you write...

December 2, 2013


Advent Computing: Bits

If you watched yesterday’s video, you’ll have spotted the symbols that were being written to that “infinitely long” tape were “1” and “0”. There’s a reason binary – counting with only ones and zeros – is used so extensively in computing, and it’s essentially that it’s much...

December 1, 2013

The Turing machine

Advent Computing: The Turing machine

If we’re going to have a series of posts about computer science, it’s probably helpful to define what a “computer” is. So let’s do that. The standard academic definition of a computer is what’s called a “Turing machine”. It goes a little bit like this:...