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zarwil

8 bit binary adder

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Hello! I've been away on holidays for a few days and figured I'd download the game on my laptop and do something with the logic gates. This is a pretty basic binary adder without bells and whistles, but I can expand it with subtraction, multiplication and division later on. 

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To the left you can see a compact version of the adder with color coded nodes for input/output. To the right is the non-compact version with the top layer expanded to show what each layer looks like.

 

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A simple computation: 10100010 + 11100000 = 00110010  (69+7 = 76)

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If you do a computation that is too big (an output bigger than 255, or 11111111) a small lamp will light to signal overflow.

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This is the back of the adder. Black nodes are input. The back panel is input A, and the panel on the right is input B. Input bits are ordered from left to right   | 0 | 1 | 2 | 3 |   on the bottom row, and   | 4 | 5 | 6 | 7 |   on the top row. There is also yellow paint behind the bottom left node to mark the least significant bit. The output panel is the same, but with red nodes. At the front of the adder is a red node for overflow.

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This is the non expanded version. There are 8 layers of 1bit full adders stacked, and you can see how one of them works in the expanded top layer. Each layer is powered by its own generator, which is completely overkill, but I just wanted to make sure there was enough power because I ran in to troubles earlier when I only had one big generator to power everything. The critical path of this thing is quite long so I made sure I had enough. In total the adder has 96 components if you don't count nodes and the lever panel.

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I'm gonna make a youtube video of this when I get back home. This laptop isn't fast enough to play the game and record at the same time and it's quite painful to play on a touchpad. 

I was going to release the composition for this so you could try it out, but while making this post I found out that one of the input levers wasn't connected. It's getting late so I'll fix it tomorrow and come back then.

 

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