Minecraft – Redstone Logic Gates

Everyone BB Q Kyle here on stream a lot of people have been asking me to teach them redstone well if you’re gonna be a big redstone circuit creator you’re going to have to learn logic gates now what logic gates do is they take an input from one or more redstone sources

And whether or not those sources are providing a redstone signal will decide whether or not that circuit sends a redstone signal now it sounds very complicated but it’s really just an if-then statement for example if it’s cold outside then I’m going to wear a jacket that’s all these redstone

Circuits are doing is making a decision based on certain conditions it sounds complicated but it’s really very simple let’s get into the first one to show you what I mean so behind this wall is the very simplest of all the logic gates it is the input output gate which basically means if the

Input is on then the output is on now there’s our if-then statement and every one of the logic gates has an if-then statement let me show you what I mean if the input is on then the output is on now here is the redstone circuit for the input/output gate as you can imagine

It’s very simple what I’ve done all down the wall is all the inputs will have a repeater behind them and the outputs will not so here we go if the input is on we follow it then the output is on very simple the next gate we’re gonna go

Over is the not gate which means if the input is not on then the output is on once again all our if-then statements are going to end with then the output is on so here we have the input is off or the input is not on and the output is on

Now if I flip this switch it goes off now anyone who’s done any amount of redstone work will know exactly what this circuit looks like so now here’s the circuit it’s very simple once again here’s the input and then here is the not gate these two blocks here it’s

Simply an inverted torch that’s all it is so if we follow the circuit from the input to the out but if the input follow it all the way down when we have our not gate which means not on so if the input is not on

Then the output is on now moving on to the or gate this is the first one with two inputs the statement that is made by this gate is if the left input or the right input is on then the output is on as you can see right now they’re both

Off so the output is off but if one goes on or the other goes on the output turns on and with or if both of them are on the output is still on once again it is a very basic circuit here is our or gate it is simply two inputs being merged

Into a single output so the way we would read this if we follow the circuit from the inputs is if the left input is on or the right input is on then the output is on simple now a quick word about the input/output knot and or gate every gate

From here will be comprised of these three logic gates basically from now on what we’ll be doing is putting together these three logic gates in different configurations to make the rest of the logic gates the first example of this is the nor gate basically the F then

Statement we’re trying to make is if the left input is on nor the right input on then the output will be off basically meaning both of these have to be turned off or there to be an output let’s take a look at the circuit so here’s our nor

Gate and basically all it is is an or gate that outputs into a not gate so if we follow it from the inputs if the left input is on nor the right input on then the output will be on basically meaning both inputs have to be off for the

Output to be on so coming up to our next logic gate it’s and which is as you can guess if the left input is on and the right input is on then the output is on as soon as we turn one off the output turns off so here’s where the

Circuits start to get a little bit more complicated we have an or gate that leads into a not gate so this is a nor gate but also on the inputs we have not gates so let’s read the circuit if the left input is not on nor the right input

Not on then the output is on now this has a double negative in it which we can get rid of simply by changing it to using an and if the left input make this whole gate and and gate if the left input and the right input are on then

The output is on so just as ORS opposite is nor ands opposite is NAND which basically means that the outputs that you would normally get on the and gate are inverted so we have both of them off or just one of them off the output is on

But as soon as we turn both of them on the output turns off and as you can guess this is the circuit it is basically an and gate where we inverted the output but the and gate already has a not gate at the output so we replace

The not gate with a simple IO gate which basically just means having nothing it’s just a straight redstone run to the output so here we go let’s read the circuit if the left input is not on or the right input not on then the output

Is on another way to say that once again this is a NAND gate so if the left input is on NAND the right input is on then the output is on so here is quite possibly the most difficult gate to understand it is exclusive or or XOR for

Short if you’re spelling it out meaning that if the left input is exclusively on or the right input exclusively on then the output is on note that when I turn them both on the output turns off this is how it differs from a standard or gate now

As all of the more complex logic gates are comprised of simpler ones so is this one so let’s simplify that statement a little bit another way we can say it is if only the left input is on or only the right input is on then the output will

Be on so we’re going to use and or gate since then or was used in the statement another way to say it is if the left input is on and the right input is not on or if the left input is not on and the right input is on then the output is

On so we’re going to need and gates not gates and or gates let’s see the circuit now here it is in its present form it’s very hard to understand very hard to comprehend so what I’m gonna do is take out a lot of the redstone and then I’ll

Build it which will show you exactly how this works there we go I have taken out the functional part of the redstone circuit so all we have is an input from the left running into the back left of the circuit and then the input from the

Right running into the back right of the circuit right now I have the first condition set as to when we want the output to turn on the left input is on and the right input is not on so we have an and statement we’re going to need an

And gate now the one we’re going to do looks a little bit different but is essentially the same thing as the other one we did we’re here are two not gates running into the input of an or gate and the or gate runs into a third not gate there we

Go so the left input is on and the right input is not on that word not means we’re going to need a not gate so place our torch that will invert the signal coming into this block and then our output runs into the other end of the

And gate now if we connect the output of the and gate to the output of the circuit the output turns on but there’s another condition in which we want the output to turn on and that’s if we reverse the inputs so now the left gate

Is off or not on and the right gate is on so since now we have the opposite condition that we also want to turn on the opposite condition being the left input is not on and the right input is on we’ve got to create a circuit that

Will turn on the output under this condition well it’s the exact same as we did here we just have to do it again on this side so once again we’re going to build our and gate which will mean to not gates running into an or gate that

Runs into a not gate and we’ll wire that into our output so right now we have if the right input is on and the left input not on then the output is on now all we have to do to make both statements turn on the output is wire on both at the

Same time so here it is all I’ve done is put back what we took out to make the other half of the circuit so let’s read it if the left input is on and the right input not on or the right input on and the left input not on then the output is

On you see we ended up with this or gate and that is exclusive or so now we come to exclusive ORS opposite exclusive nor so with both of them being the same both of them being either on or off we get an output but if it’s one or the other we

Get no output now how do we do this well with that and in there once again it’s the opposite of exclusive or so we have an exclusive or circuit here and then we just run the output into a not gate to get exclusive nor now this is a gate

That I wasn’t even going to cover but in the interest of being thorough I decided to throw it in here I have can’t think of a time I’ve used this gate but it is an official logic gate so we’re gonna cover it is the implies gate and this is

The only gate where the inputs are not interchangeable and the way this is read is the left input implies the right input let’s take a look at the circuit you have the left output going into a not gate running into an or gate and on

The other end of the or gate the right input runs directly into it and then that directly goes to the output basically what this means is when the left input is on and the right input is off you will get no output but under any other can

Bishan you get an output so these are the nine basic logic gates now some people may argue that there are more but I decided to leave out anything that involves memory or timers and just include these nine that’s it that’s all I’m including in this video we may cover

The other ones in another video but for right now these are the nine and if you want to create big complex redstone circuits you will need at least one of these if not multiples so I hope you learned something hopefully this helps with a redstone circuit you’re trying to

Design in the future and until next time guys take it easy