Minecrafting Adders

George Boole supposedly proved that every operation in math can be reduced to a combination of three operations: "and," "or" and "not." This had a great influence on the development of computers years ago. When teaching a CS class for Learningtech.org I was introduced to the Cedar Logic software, which allows you to create interactive virtual logic gates. Here's a two bit adder made from a couple of gates (four, actually):

The two inputs on the left are on, so the output is the binary form of 2: on and off or "10."

A student (thanks, Nathan) showed me how he made logic gates in Minecraft using redstone, the game's "electrical" substance. I didn't think much more about it until recently, when I bought Craig Richardson's book on modding the Raspberry Pi's version of Minecraft using Python. It can be used on the full PC or Mac version as well, so I experimented with writing  code to build houses and cities and then blow them up with TNT. It's fun!

For those students who would rather create their structures by setting blocks the old fashioned way, you can simply scan an area (ok, a volume) with the "getBlock" function and some nested loops and save each block's information  for building a house in a list or .txt file. Then you can run the process backwards and recreate the structure at another location.

def duplicate(x,y,z,l,h,w):
    '''saves all the blocks in an area'''
    blockFile = [] #list for block info
    for i in range(l): #loops through the x-values
        blockFile.append([]) #starts new array for rows
        for j in range(h): #loops through the y-values
            blockFile[i].append([]) #starts new array for columns
            for k in range(w):  #loops through the z-values
                #put block data in row and column array:
                blockFile[i][j].append(mc.getBlock(x+i,y+j,z+k))
    return blockFile

For instance, the figure above was made using this "copy and paste" procedure. The structure on the left was the original, which I copied and pasted in the middle. The data for the color of the wool and the orientation of the torches was lost. I needed to modify the getBlock function to "getBlockWithData" and then the structure in the foreground was identical to the original.

Unlike in the minimized version of Minecraft available on the Raspberry Pi, in the Windows version I could also use redstone. It made me think of Nathan and the logic gates. A web search got me the design for an AND gate. The output on the left is only on if both switches on the right are ON.

A coworker helped me "optimize my code" and make an AND gate out of less blocks:

So I made the gates from the adder at the top and connected everything with redsone. Using my duplicate function I copied and pasted the components until I had a 4-bit adder:

(My previous adder is on the bottom of the screen.) The switches are set up to add 11 + 1. In binary that's 1011 and 1. The 5 glowstone pillars at the top of the screen are the digits, and they're off, on, on, off and off, so 01100 or 12 in decimal. It works!

Getting in creative in Minecraft is a great way to learn about 3D coordinates and interacting with programs using Python. Then you get to walk around in your creation!