2 bit Adding Machine in Minecraft

I just made a 4-bit adder! Here's the video: http://www.youtube.com/watch?v=iGy_f_TDeQM . It's still uploading as I write this but it'll be done soon.

I've been playing a game called "minecraft" a little bit recently, and I was inspired by the 16-bit ALU (arithmetic logic unit) video to make a little 2 bit adding machine. It's really simple and works as far as I can tell, with only one problem: if one or both of the inputs are 00, then my machine breaks. (Right now it says that 00 + 00 = 110, which is obviously not true).

It's also impossible to fill up all three bits in the output, since the maximum value that two bits can hold is 3 (2^2 - 1) and the maximum value of three bits is 7 (2^3 - 1).

I'm hoping that I can expand this concept into a four-bit machine sometime, but that takes time and patience, and I tend to be short on both when it comes to long projects.

EDIT 11/6/2010: The schematic for this is here: http://img708.imageshack.us/img708/4277/addpu.jpg .

For more on logic gates, this article is great: http://en.wikipedia.org/wiki/Logic_gates

EDIT 2: This is the schematic for a correctly working adder generalized to n bits: http://img574.imageshack.us/img574/1281/photombn.jpg . The section labeled 1 is a "half adder", which doesn't utilize a C (carry) in value. All other bits require a "full adder" (label 2) which has a carry in and carry out. The gates in label 2 can be repeated as many times as desired for a n bit adder; for example, an n bit adder would have 1 half adder and n - 1 full adders.

Category:

Science & Technology

Tags:

• bit
• minecraft
• computer
• ALU
• adding
• machine

[1337CSS3]

Sorry to break this to you, but this isn't quite correct - try adding 0 and 2. It will give you 5. The logic you're using here isn't quite sound. :-/

[CleverTangent]

@1337CSS3 I know... read the description...

[amigojapan]

Ok, I figured out how to make a not gate from the video you have, the trick is to put redstone (the inpiut) to the box, then put a torche on top, then put a torche on the other side of the box, then put more red stone (the output) interesting, I guess it would still be useful for us non-electritians to understand the diagrams of how to make AND XOR and NAND gates. if we can make NAND gates, I think we can use mcedit to import and make many replicas of the NAND gates to make a complex system

[CleverTangent]

@amigojapan I'm getting errors when I try to post links, but the MinecraftWiki article on "Redstone circuits" will help you a lot here, especially the section on logic gates. Just google "minecraft wiki redstone circuit" and the first result is what you want

[kescores]

At 2:02 you said that you're a computer scientist?

Sorry asking, I can't understand english pretty well... Is it possible to get that kind of hardware information in computer science studies? Or the right answer would be electronic engineering?

[CleverTangent]

@kescores Generally, what I'm doing here (which boils down to circuitry) is more in the realm of electrical engineering, but since Computer Science and Electrical Engineering overlap so much you'd probably be able to learn about this sort of thing from both.

In its purest form, what I'm doing here is discrete mathematics, which is in and of itself a form of pure math, and not of CS or EE, although it's used heavily in both.

[ThePolarisKid]

its not a fun little game. and its not creative. ITS SURVIVAL and the BEST GAME

[randallmckay]

binary

[N0L3G1T8K1LL]

Can u make one for a 4 bit adder?

[forrest0no]

Hey i need help. I built a 2 bit adder with ripple carry but its doing some odd stuff. When i add 3 + 3 it gives me 3, and that just goes on. It is the corrected one, and i cant seem to fix it.

[iRicecrispy]

Oh hey btw by overflow i just mean, if you have the xor gate at the beginning of each bit you just put 3 blocks above the first set of torches, on top of that redstone and on the side of that a torch, this torch will only be on if both inputs are on, connect that to a xor gate which is connected to your second bit and your output should be right.

I'm not sure if i'm helping here, i just don't know how well this is going, and well if it helps its only good and else it's a waste of my time =P

[iRicecrispy]

Oh come to look at it... the adder in the vid needs some tweaking and a bit better architecture... Nothing to brag about but my adding machine is 8 bit and (9, 5, 90) (x, y, z) (display and input included) which is allready quite inefficiently large...

[iRicecrispy]

Lmao before i made a CPU i made an 8-bit adding machine too, I think i just did a row of xor gates with overflows to a second row behind the next bit... I am not sure if i did it quite right but it worked swell =P

Anyway the only thing you need to prove you know your stuff is 2 bits input with 3 bits output (including the overflow) i just wanted to add nubers up to 255 =P

Anyone feel like making a gpu? make like a minecraft computer with a 4x4 screen to see what we can do? =P

[SeanA921]

ive made a 5 bit adder =) i could easily make it larger but i really cant be bothered haha

[Thetb93]

@ThePolarisKid but how did you survive without coputer machins?

[minecraftarcutect17]

on a diferent vid someone bilt a calculater were there's one lever that makes the + and - sign then more levers on one wall and wore on another then after you choose your front and back numbers witch all the levers are for it will show you the awser and equation on a wall in redstone toreches

[shadowzard7]

you cant use brilliant like that unless you have an accent

[IAMDISAPP0INT]

Wut

[Naaaaaaayr]

Go Jackets.

I've heard of people making circuits for an EE (maybe CE?) class in Minecraft...The TA's were a bit taken aback.

[DInmoketrijzd]

You just made me realize how Bit-adders work.. HOW CAN I THANK YOU ENOUGH?! :)))

[Cranklesaurus]

omg, i have a 2 bit adder on my channel too! whoo!

[Rachman1337]

You should just build the schematic on the Wikipedia page for a full adder.

Works like a charm and is relatively easy build.

[WoWired]

But can it divide by zero?

[Jasper2428]

2 bit computer? All I can think of is 01 10 and 11, LOL sooo, the biggest thing you can do is 1+2?

[Jasper2428]

2 bit

[thegreataustralia]

you dont have a carry i noticed

[WindWalker940]

im in the first year of highschool (the swedish school system is strange(im 16)) and i have just learned how binary is calculated, but can binary output negative values? or is binary just absolute values?

[1337CSS3]

@CleverTangent Sorry, I didn't see that - my bad.

[Gineacraze34]

schematic plz