Minecraft name: DepressedCubic
What do you like the most about redstone?: Not only the fact that it makes Minecraft turing complete, but also the fact that redstone engineering is a creative endeavor, closely related to CS and to a lesser extent Mathematics (two things I really, really love)
What’s a thing you have made which demonstrates redstone knowledge?: A 4-bit ALU, of the kind shown in Nisan & Schocken’s book “The Elements of Computing Systems”.
What does the thing do?: It has 8 inputs; two 4-bit inputs x and y (data), and 6 bits (opcode):
NOTE: each of these is done in precisely the order written; for example, nx is applied after zx.
zx - if zx = 1, make x equal to 0; otherwise, do nothing.
nx - if nx = 1, negate x; otherwise, do nothing. (bitwise NOT)
zy - if zy = 1, make y equal to 0; otherwise, do nothing.
ny - if ny = 1, negate y; otherwise, do nothing. (bitwise NOT)
f - if f = 0, out = x AND y (bitwise AND); if f = 1, out = x + y (2s complement addition).
no - if no = 1, negate out; otherwise, do nothing.
And three outputs:
out - the 4-bit output.
zr - zr = 1 if out = 0.
ng - ng = 1 if out < 0; that is, if the leading bit is 1.
Image(s) and/or video(s) of the device:
What do you plan on making for your build trial?: A 4-bit ALU, just like the one shown.
Do you agree with the rules?: Yes, completely.