[Music] hi my name is lamar free and i'm an engineer here at adafruit industries and this is where i do engineering and design and i design circuits for fashion and music and technology my name is federico gomes-sores and i'm a software developer with microsoft hack for good and i look into using technology to help us solve some of the big social problems of our times [Music] you may have heard that computers work on ones and zeros or you may have seen scary scary-looking visuals like this but almost nobody today actually deals directly with these ones
and zeroes but ones and zeros do play a big role in how computers work on the inside inside a computer are electric wires and circuits that carry all the information in a computer how do you store or represent information using electricity well if you have a single wire with electricity flowing through it the signal can either be on or off that's not a lot of choices but it's a really important start with one wire we can represent a yes or no true or false a one or a zero or anything else with only two options
this on off state of a single wire is called a bit and it's the smallest piece of information a computer can store if you use more wires you get more bits more ones and zeros with more bits you can represent more complex information but to understand that we need to learn about something called the binary number system in the decimal number system we have ten digits from zero to nine and that's how we've all learned to count in the binary number system we only have two digits zero and one with these two digits we can
count up to any number here's how this works in the decimal number system we're all used to each position in a number has a different value there's the 1 position the 10 position the 100 position and so on for example a 9 in the 100 position is a 900. in binary each position also carries a value but instead of multiplying by 10 each time we multiply by 2. so there's the ones position the two's position fourth position the eighth position and so on for example the number nine in binary is one zero zero one to
calculate the value we add one times eight plus zero times four plus zero times two plus one times one almost nobody does this math because computers do it for us what's important is that any number can be represented with only ones and zeros or by a bunch of wires that are on or off the more wires you use the larger the numbers you can store with eight wires you can store numbers between zero and 255 that's eight ones with just 32 wires you can store all the way from zero to over four billion using the
binary number system you can represent any number you like but what about other types of information like text images or sound it turns out that all these things can also be represented with numbers [Music] think of all the letters in the alphabet you could assign a number to each letter a could be 1 b could be 2 and so on you can then represent any word or paragraph as a sequence of numbers and as we saw these numbers can be stored as on or off electrical signals every word you see on every webpage or phone
is represented using a system like this now let's consider photos videos and all the graphics you see on a screen all of these images are made out of teeny dots called pixels and each pixel has a color each of the colors can be represented with numbers when you consider that a typical image has millions of these pixels and a typical video shows 30 images per second and we're talking about a lot of data here [Music] every sound is basically a series of vibrations in the air vibrations can be represented graphically as a waveform any point
on this waveform can be represented by a number and this way any sound can be broken down into a series of numbers if you want higher quality sound you would pick 32-bit audio over 8-bit audio more bits means a higher range of numbers [Music] when you use a computer to write code or make your own app you're not dealing directly with these ones and zeros but you will be dealing with images or sound or video so if you want to understand how computers work on the inside it all comes down to these simple ones and
zeros and the electrical signals in the circuits behind them they are the backbone of how all computers input store process and output information [Music] you
