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Create a functional logic gate using nothing but wires tied into knots. A single-level puzzle made for the 2022 Confounding Calendar.

This game was made for the Confounding Calendar 2022

WASD/Arrow Keys - Move cursor
X/Space - Toggle drawing on/off
Z - Undo
R - Restore save point

Draw wires on the screen by moving your cursor while in drawing mode. Wires carry power. Make a loop of wires, then pull it through in any direction to create a knot.

Knots will output the opposite state of the wire going into it. For example, if the wire going into a knot is off, then the wire coming out of the knot will be on, and vice versa.
Knots have only one output, the wire you see slightly overlapping the knot, and one input, which can go in any of the other three sides. Attempting to add more input wires will not work.
Knots cannot loop back into themselves, if they do they will become locked, turning off and darkening in color.

At the bottom of the screen are two inputs, and at the top is the output. Your goal is to create a circuit that passes all of the cases shown on the right, creating an XOR gate.

Press X/Space with your cursor over a case to test it. If the output is correct, a green box will surround the case, showing your solution passed.
Making any changes to the circuit will reset the successes. Remember, your goal is to create one circuit that satisfies all four cases.

Press X/Space with your cursor over the + to create a save point, and press R at any point to restore it.

Post your solution in the comments (Preferably as an imgur link to not spoil others!) There is no one correct solution to the problem, and I'd like to see how you approached it!
If you want an extra challenge: how small can you make the footprint of your circuit? Meaning: how small dimensions could the board be and still fit your solution?

Good luck!

Rated 5.0 out of 5 stars
(3 total ratings)
Made withPuzzleScript
Tagscircuit, circuit-builder, PuzzleScript, zach-like


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My initial solution is rather inelegant, but the second one is the strange product of my attempt to optimize for space.

something weird happens when you connect the inputs of two not gates facing away from each other with a length one wire. extending the output wire causes the output to change.


I feel like my past experience of minecraft combinational logic circuit helps here tremendously.

(1 edit) (+3)

Lovely idea! The way the geometry becomes an obstacle to the "obvious" solutions is very cool. Here's mine:

I agree, making it work in 2D was fascinating. and, I ended up with the same layout!

Here is my solution:

My goal was to keep it symmetric.

I can’t figure out the intended behaviour regarding 3rd and 4th connections to knots, and also whether knots have any directionality. It might be very buggy.

I absolutely loved your SUBLEQ game for Last Call btw :)


Thank you! In terms of third/fourth connections to knots: they are not possible. Knots have one input and one output, attempting to connect more will not work. Knots do have directionality, they have an input, and an output. The knot is shaped like a C and you can see the output coming out of the hole of the c, the input can go in any of the other three sides. I'm glad you liked SUBLEQ! I made this as a little prototype for a similar Zachtronics-style puzzle game, so I may continue this concept as part of a larger game. Thanks for playing : )

You need to private the game on search too.

Thank you! I just fixed it. I'm able to see 3 of your games for the confounding calendar on your account as well, is that intentional?

But I unlisted the games and hide them from my profile...

They are hidden on your creator page, but when I click on your profile from your comment I see them. Same for me however, so I don't think you did anything wrong!