User:Larix

I've developed a logic discipline which could actually deserve the label "Minecart Logic", if it wasn't already taken. So i've tentatively dubbed it "Minecart Pathing Logic", since, other than the known circuits, it is based on directing moving minecarts and manipulating their paths instead of placing resting carts on top of pressure plates.

Here you can find what i've written up about this logic discipline:

User:Larix/MPL

Very compact mechanical adder with instant carry calculation and subtraction capability:

User:Larix/Adder

Some findings on the mechanics of minecart collisions:

User:Larix/Minecart Collisions

Odds and Ends

A collection of Dwarf Logic projects, ranging from an overengineered silly joke to overengineered solutions for simple problems or challenges to... overengineered overengineering:

hq9+ Interpreter

• Doing my very best to push the envelope of dwarfputing, i built a dwarven computer to execute programs written in a high-level programming language. Since so far, dwarven computers have effectively worked with machine code, this is a huge leap forward!!

The language in question is hq9+.

thread on the Dwarf Fortress forum:

http://www.bay12forums.com/smf/index.php?topic=130986.0

I am especially proud of the unary memory device.

The Drunk Number Generator

• Dwarfs are always so sloshed that when they try to be random, they still just end up drunk. Their drunk stumbling around the meeting hall can be used to derive irresponsibly unpredictable signals, which in turn can be converted into apparently random numbers. Be careful when constructing such contraptions on your own computers, intoxicated computers can be quite difficult to handle.

The double-roller "bit splitter" should be pretty close to the optimum in turning non-periodically timed events (like citizen-triggered pressure plates in a well-travelled area) into pseudo-randomness.

http://www.bay12forums.com/smf/index.php?topic=129226.msg4452422#msg4452422

Security Blast Door

• Do you lack the patience to wait a hundred steps for a pressure plate to re-set and close a door? Are you annoyed by dwarfs dragging their feet when ordered to pull the "close that door!" lever? No problem, you can get a door to close as reaction to an "on" signal, potentially in less than ten steps. It just takes ~400 power and 25 rollers and pressure plates and link jobs.

http://www.bay12forums.com/smf/index.php?topic=128095.msg4449221#msg4449221

Taming the diagonal Minecart

• Just working out that diagonally-moving minecarts are notoriously unwilling to follow track directions only served as an incentive for me to step up my game and tame the wild diagonal minecart. I succeeded in getting such carts to stay in holding loops, cycle through repeaters and even hold a bit of information by their rotation direction in a read-writeable 'memory cell'.

There's no need to use an extra minecart for every bit of memory you wish to store, a single minecart can hold a full byte of information.

Oh, and i got a rudimentary base-seven memory device or adder to work, based on regulating water depth and measuring it with pressure plates.

Controlling diagonal minecarts; one-cart one-byte memory; seven-state fluid memory/potential base-seven adder? http://www.bay12forums.com/smf/index.php?topic=131325.msg4621257#msg4621257

Multiplication with beyond-binary result calculation

• Binary multiplication has a simple basis, but tends to get unwieldy because so many adders are needed to put all the partial results together. DF's mechanical logic, however, offers amazing options to compactify the adding-up process so that for a multiplication of two eight-bit numbers, no more than fifteen addition steps are required. But how can this be, when up to sixty-four signals are generated before any addition takes place, and the addition is liable to produce twenty carries? Simple (or not so simple): by adding more than three signals in a single circuit. A load-based "how many inputs are on?" circuit can not only check against a defined threshold of inputs before switching off, by using the output-generating pressure plates to re-configure the circuit itself and thus change the load, it can check for different significant load limits in succession and enforce a stable state when the "correct" output is reached.

I endeavoured to make it more elegant by "pre-processing" the carries generated and unwittingly introduced another problem - the "resistor-based input counter" can process new inputs turning on, but will ignore inputs turning off during operation, something that will happen in the course of preprocessing. Conservatively, this problem can be handled by not pre-processing the generated carries and just passing up to seven up to the next bit, meaning you'll have to handle up to fourteen in- and seven outputs.

Or you can build a "consistency check" routine into the resistance counter, which massively increases the parts count but adds a whole new level of elegance and potential for further use. Equipping a multiplier with the presented finalised "count to ten" circuit will likely use at least as many parts as a Wallace or Dadda (or un-organised old-school) adder to collate the partial results, but allows calculating all carries of a bit and its sum on the same circuit.

Mechanical Multiplier (binary), 8x8 bits, with "single-pass" addition. As a possible improvement, the 0-10 Volume Meter

http://www.bay12forums.com/smf/index.php?topic=132977.0

The Signal Grinder

An unbeatably dwarven (and delicious) power-to-signal converter.

It seems that people think that screw pumps and rollers are the only power-driven "output devices". This is not true - there's another building that accepts power: the millstone. And like the two others, it can be used to transform power into a signal. All you need is a dwarf with the milling labour, a manager, millable plants and empty bags.

Construction:

###==1==
#o^..c..
###==2==

o - Millstone

^ - citizen-triggered pressure plate

=1= - stockpile accepting only millable plant (preferably without barrels)

=2= - stockpile accepting only bags

c - chair, assigned as office for the manager

The circuit must be primed by the manager. Order a number of "mill plant" or "mill seeds to paste" jobs. Once they have been approved, they can be assigned to querns or powered millstones. Milling jobs will only be assigned to a millstone if the building receives power and are automatically cleared from the millstone's job list the moment power is disconnected.

As soon as the millstone receives power, it will line up milling jobs and sooner or later (or much later) a miller will show up to mill, passing over the pressure plate when collecting plants and bags and bringing them to the mill. The plate will get activated repeatedly until power is cut or until the miller decides to eat, drink, sleep, party, go on break, pick up new socks or relocate a sheep that moved one step out of its pasture, or until all milling jobs have been performed.

By choosing the number of milling jobs ordered through the manager, a longer or shorter period of signal activity can be selected. As a notable benefit, this device not only generates signals from power, it also produces valuable powders (dyes and cookable flours/sugar) and trains dwarven skills (organiser and miller). And since it in fact uses dwarfs to turn power into signals, it can rightfully claim to be the only truly dwarven power-to-signal converter.

Technical data:

Extrapolated latency - 200-12 000 turns (the latter if there's only one miller, who just went on break when power turned on)

Produced signal - intermittent, with a period of ~200 steps. Acceptable for opening/closing bridges or extending/retracting spikes.

List of Materials: 1 millstone, 2 mechanisms, one chair, millable plant(s), empty bag(s). The chair can be deconstructed after priming the circuit, to recover materials.

Very compact incrementers and a collection of other computing components

The second post in a thread originally made to present a pseudo-random RNG using standard computing procedure - a linear-feedback shift register. During that construction, i got some ideas for smaller dwarven computing stuff, so went and built those, too. Some of them may be of practical use (as far as dwarven computing can be considered practical).

The water level measurer is highly theoretical for now, since i'm not aware of any kind of liquid-based computing that'd produce liquid of discrete depth.

The two designs of all-purpose logic gates are primarily concept demonstrations, to show what minecart computing is capable of. Each can distinguish the four possible states of two binary inputs accurately, using only two input devices/connections, which don't need reconfiguring for different logical conditions.

The memory cell is still more for showing off - there are compacter and more reliable powerless memory cells possible. The design shown has been demonstrated to be a workable adressable memory cell which reliably acquires and holds an input after enabling, until reset, and can be read out to a memory buffer, which can be shared with other memory arrays.

The binary and ternary incrementer are very compact and to my knowledge perfectly reliable devices. I fully intend to use them in future projects.

For now, the synchronous toggler is another curiosity, but it's a great step forward in compactness and regularity for such devices.

Grab-bag of mechanical and minecart logic stuff, crammed into a thread full of weird computey things: http://www.bay12forums.com/smf/index.php?topic=135141.msg4881573#msg4881573

Division by minecart collision

Since i successfully built devices to perform addition, subtraction and multiplication, i felt the need to complete my mastery of basic algebra by designing something that divides. This is notoriously difficult to achieve automatically, because to the best of my knowledge, binary division is a sort of iterative subtraction and there's no reasonable way to do this without a massively complicated processor, like the one shown in The Almighty Dwarven Calculator.

Since the reasonable way to do it would be to laboriously repeat a feat already achieved handily by someone else, i settled for an unreasonable way to do it: bashing minecarts together. In case you didn't know, bashing minecarts together is the new magma. If it's not the answer, the question has been formulated wrong.

Since the output speed of a linear minecart collision is simply the speed of the incoming minecart, multiplied by its mass and then divided by the mass of the outgoing cart - capped at incoming speed itself - every such collision effectively performs a division. By choosing and changing weight and speed of the incoming cart, the dividend can be changed, and by selecting outgoing carts of different weights, different divisors can be chosen. By letting the outgoing cart run freely for a constant number of game steps, then stopping it, the output speed can be measured (in integer numbers).

The entire complication of the device lies in selecting and combining carts and speeds to implement a sufficiently large range of divisions to run. You could of course just inscribe a huge lookup table of sample divisions into your fort's floor (or simply put it into the notes). My dividing machine's primary merit is making the looking-up of division results more entertaining through colliding minecarts.

http://www.bay12forums.com/smf/index.php?topic=15096.msg5129395#msg5129395