I built an eight-bit ripple-carry adder over the weekend and have just started the digging to take it up to sixteen bits.. I've seen a few theoretical designs for full adders on the wiki and such, but never a complete system.
See it in action here: http://mkv25.net/dfma/movie-1084-numberabbeydemonstration
This is the business part of the fort. There's a half adder on the far right and then seven bits of full adders. To the south are some excavations for the impending expansion to sixteen bits.
Most of the up staircases are for dwarf access but the topmost ones are the water inlets.
The paired down staircases are the drains. The pressure plates on the right sides of the adders are the sums and the ones on the left are the carries.
Everything of the same color in each adder shares a trigger. The red and blue buildings are triggered by the input levers, and the green ones by the carry pressure plate of the adder to their right.
The brown doors are not linked to any triggers and are only there for the convenience of dwarves.
Those are one-tile drawbridges in there, which are perfectly like inverse floodgates, except that whereas floodgates only annihilate water when they close, the bridges would crush anything that got caught in them ;)
The only inconvenience with them is that it's impossible to tell directly whether they're open or closed; you have to deduce it from the state of the nearby floodgates and the assumption that everything is linked up correctly.
The adders are designed so that whenever the water has a path from the inlet to one of the pressure plates, it doesn't have to travel diagonally, and therefore maintains pressure. The drains are deliberately diagonal, so that the pressurized water piles up on the plates and triggers them, and drains more slowly than it accumulates.
The next level up is the access hallway for construction and maintenence. All of those dwarf-access stairwells are covered with hatches, although some of them didn't show up in the image export. This is necessary to keep the pressurized water from circumventing all of the logic and always triggering all outputs by going through the access tunnels.
There were a number of other considerations in the design which I'll write about in more detail some day. Suffice it to say that I abandoned two forts before starting this one because of irrecoverable design flaws. - Kanddak
There are 11 comments for this map series, last post 2009-03-31
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