RCA 4 Bit ALU

Build image: 
In-game name (NO VISITORS! Must be LEARNER rank or higher!): 
HowBoutNah
Builder name(s) and current ranks: 
HowBoutNah: Learner
Creation location: 
1009 156 -446
Machine Features: 

It only has 5 functions, Invert A and Invert B, OR, Flood Carry and CIN. I also added a CU decoder into opcode so that you can do functions AND, NAND, OR, NOR, XNOR, XOR and Subtraction. Let me tell you how it works.

The togglable inverters are simple enough. I made the OR by creating a toggleable torch line that makes sure that the carry torches are always off. By doing this, it makes sure that the output is never set to 0 because of the fact that both inputs are 1, as well as blocking carry, making a bitwise OR effect.

For the Flood Carry, I took a different approach. I made a torch line that would make sure that the carry is always on if enabled, which would 'flood the carry'. To make an XNOR gate, you would have to do FC and CIN, as I didn't make it so that Flood Carry also did CIN.

This set up lets you do all bitwise operations from AND to XNOR. This, however, can not do gates like ONLY.

How To Use: 

The functions Invert A, Invert B, OR, FC and CIN allow you to do a lot of functions using these combinations:
AND = Invert A + B + FC + OR + CIN
OR = OR
NOR = FC + OR + CIN
NAND = Invert A + B + OR
XNOR = FC + CIN
XOR = FC + Invert B + CIN
SUB = Invert B + CIN

However, I hooked them all up to an opcode decoder, so that you can flick the lever for which function you want to do and flick the inputs.

Request status: 
Not approved

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