TheWallbars Application - 4-Bit ALU

Minecraft Username: TheWallbars

Have you read the Read Before Posting post?: Yes.

Your favorite thing about redstone: Redstone helps me practice building and testing computer circuits, as well as applying computer science knowledge from my college courses.

A build you have made which demonstrates redstone knowledge (This is your trial build): A 4-bit ALU using a CCA.

Explain what your build does in detail:
The base of the build is a 4-bit CCA, which uses two inputs A and B, carry-in signal Cin, and a cancel signal Ca, to output the addition of two 4-bit numbers to main output O and carry output Cout. The inputs are compared through an xnor gate, which sends two signals: one is negated and sent to the xor to be compared to the carry-in signal, and the other serves as the carry-out signal. The inputs are also compared via a nor gate, which disables the cancel signal when true. The carry will only pass when the carry-out signal is enabled and the cancel signal is disabled.

Each input is compared by its own xor gate to an inversion signal. When this signal is enabled, A!/B! will be sent as input to the system, rather than A/B. There is also a carry input, which adds 1 to the xor gate before the first output. Using B! in combination with this carry input will generate 2's compliment from a standard binary input, allowing for subtraction. There is also a flood carry input, which sets each Cin value to 1, negating the main outputs. Finally, there is a function which replaces A xor B with A or B, allowing for bit-wise operations.

Images / videos of the build:

What is the name of the warp for your build on ORE?: TheWallbars

Provide your results after completing the ORE Binary Quiz:
Binary Quiz completion certificate:

Completed by TheWallbars in 3m37.728s on 5/13/2025, 23:40 UTC.
96.15% accuracy with 1/26 answers given incorrectly.
fe282195-411b-4455-96d3-ecf5f1c6b83f-54686557616c6c62617273
722w2w2p0j3w6z0y10140a6n335k3h38545s4h5wman5i64uman5mu4u

Do you agree with the rules?: Yes.

This application has been accepted!

Please review the FAQ below to learn more about the remainder of the process of getting Builder rank.


FAQ

Q: What is my next step?
A: Join the ORE Minecraft server and request a trial with any available trialers (Engineers, Moderators, and Admins).

The server IP is mc.openredstone.org and the current version is 1.20.4 on Java Edition.


Q: Do I need to trial right away?
A: Nope! You are free to request a trial at any time so long as your application is accepted (which yours is).

Ideally you want to avoid taking too long, so we strongly recommend being sure you can pass before requesting a trial.


Q: How long does a trial last?
A: This can vary somewhat across different trialers, but generally somewhere around half an hour or less. It will often take longer if you aren’t as prepared, so we recommend reviewing ahead of time, especially with help from another member.


Q: What do I need to know for the trial?
A: This can also vary somewhat across different trialers, but here are some of the most important topics:

  • Binary and Binary Arithmetic (Addition/Subtraction)
  • Logic Gates and Bitwise Logic
  • Redstone Adders and ALUs
  • Two’s Complement (Signed Numbers)

A great way to make sure you know what to expect is to ask the specific trialer what you should learn ahead of time.


Q: How often can I retry after failing?
A: There are 2 limitations:

  1. Trials can be done 24 hours after a failed one
  2. Only 2 trials can be done every 7 days

Q: What are the benefits of Builder?
A: There are 2 main benefits:

  1. Permissions to use Worldedit commands
  2. A plot on the Build server (4 times as large as School server plots)

Aside from that, there are also some minor benefits such as:

  • Running and voting in Staff elections
  • Joining the Survival and Seasonal servers
  • Option to progress to Engineer (barring additional requirements are met)
  • Interact with other Build plots (assuming permission from the plot owner)