*punch*

4000 items of debris.

Let your admin know before blowing one of these up because the lag is crushing. A /remove items command is also recommended.

A safer play would be to watch a SandALU being “recycled” on YouTube.

If you’re unfamiliar with these collapsing sand structures, they work because signs can be stacked on signs, and sand can too. Signs, redstone, repeaters, switches and buttons all pop when the object they’re attached to is broken or moved. So, a sign on a sign on a sign would all pop when the first sign is broken. These sign structures can support sand, which in turn supports the circuitry. On chain reaction destruction, half blocks make the sand break when it hits the ground.

AND NAND OR NOR XOR XNOR POOF

A logic unit takes two sets of inputs and an instruction byte, then outputs the result of that instruction. If we build in a math operation like addition, then this structure becomes an ALU, or Arithmetic Logic Unit. Your desktop CPU spends most of its time shuffling data between RAM memory and your ALU, which does the real work. That one has dozens of possible instructions.

Bit Zero – logic on right, selector wiring on left

In this build, the logic takes up about 1/6th of the blocks, with the rest used to wire it all together. Another typical feature: all six possible answers are computed at once, but only the requested answer is output. Sets of torches in a counting-up binary pattern allow only the specified operation’s result to reach the output gates. This is known as multiplexing, and that wiring is a mux, selecting one potential input of many.

Happy Anniversary RDF! Shout out to Metafilter and Reddit.

Flow diagram of a floating point adder

Floating point is basically scientific notation for binary.  Stored in a floating point number is a number of significant digits, known as the mantissa or significant, and the location of the radix point.  The radix point is equivalent to a decimal point in base 10.  For anyone who does not know how fractions are represented in binary, it is actually very similar to decimal, in that the first value after the radix point is the 1/2 place, followed by the 1/4 place, the 1/8 place and so on.

Now I should explain a little bit about how floating point addition works.  The first step when trying to add two floating point numbers is to compare the location of the radix points and shift the lower number such that the points coincide.  This allows the numbers to be added by a simple full adder.  Next, if the result from the addition does not line up with the radix point as it is, more shifting is necessary to renormalize the number.  Normalization refers to the process necessary to return the number from a nonstandard format to the standard one.  For instance in scientific notation, a nonstandard number could be 100*10^2.  This is nonstandard because the mantissa is greater than 10, however fixing this is a simple process, simply shift the decimal point until the mantissa is between 1 and 10, and adjust the exponent accordingly.  In this example, the result is 1*10^4.

My adder is organized so that these steps follow each other linearly, and as such the first component after the inputs for the exponent is a subtractor to determine the difference between the exponents.  That feeds into a special pulse generator I developed, shown here, which, combined with shift registers, shift the smaller number to align the radix points.

Pulse Generator

The next component is another of my own design, it converts the mantissa to its negative equivalent in two’s compliment if specified by the sign bit.  The component is a series of half adders, designed to add one to whatever is input.  This is useful because to convert a number to two’s compliment, you must invert it and then add one.  This is especially useful because it turns out that to convert out of two’s compliment, you do the exact same thing.  The next step for my adder is to actually do the addition, this is the large yellow component right in the middle, its just a full adder, nothing special here.  The next step is where any negative numbers are converted back to positive and the sign bit is calculated.  It then shifts the mantissa if necessary to renormalize, keeping track of the exponent all the time.

2 Wide Half Adder Cell

The one thing I did not chose to do with this adder is full IEEE 754 compliance.  Looking at my options as I started this project, I opted not to do significantly more work to provide support for numbers like 0 and infinity which cannot be represented in a floating point format as-is.  If this adder were ever incorporated into some larger project, it would not be too difficult to add such support, however for now, it does not have that.  Also important to note, if you try a calculation for which you would expect the result to be zero, the adder can behave strangely.

Finally, I would like to give some design credits, thanks to Hex-xeH on Planet Minecraft for the full adder design here: http://www.planetminecraft.com/project/2-wide-tileable-full-adder/, and thanks to CrucialCrafTTTT from YouTube for the shift register design: http://www.youtube.com/watch?v=LgAZ5iRsrLM.  This project would not have been possible without you!

So if you are ever in the area of plot NE39, and would like to give it a try, feel free!  I have linked to the wikipedia page detailing half precision floating point numbers if you wish some further explanation, and if you find any bugs or problems, just leave me a sign on the light blue wool!

http://en.wikipedia.org/wiki/Half-precision_floating-point_format

My adder, viewed from the top, inputs on the left, output on the right.

On the 27th of April we will turn 1, and do you know what that means? it means we can celebrate and celebrate we will.

Over the past year we have gained over 750 members, brought a new server (We were running on a celleron with 2GB ram for 6 months!) Even set up a school server for people to learn how to build fantastic redstone creations!
I think it is safe to say that we have the largest redstone based community in the whole of minecraft!

So from the 27th to the 29th we will be running a livestream of our members (And possibly some cool YouTube people) getting together and building the DCPU16, and addons for it.
As well as this we will be inviting the viewers of the livestream onto the server to join us and ask redstone related questions and possibly be taught interesting things along the way!

We also encourage people to join us on our teamspeak server, the IP is: mc.therdf.net
Don’t be afraid to talk to us, we don’t bite

I will update you when the time comes about livestream links and anything else that is relevant

~Shrogg

My programmable waterfall printer is able to print letters and numbers before your very eyes! It drops water is a certain sequence, arranged in the shape of different characters that have been saved by the user. If you know how decoders and ram works, you can easily add in more characters or symbols. To program it you simply choose your letter – Save it by clicking the “Save Letter” button – change to the next letter using the “Next Letter” button – And repeat up to 9 more times.

How did I come up with the idea?

The problem with redstone printers (And real printers) is that they need ink/blocks. I have thought a lot about somehow making a redstone printer that could infinitely print without the need for refueling.. But what could do this? There are only a few choices, you could set up an automatic pumpkin farm, use lava or water. An automatic pumpkin farm would be hard and I would need another block… So I went with the water idea, as water falls faster than lava, the machine would not need too much delay, and there wouldn’t be any left over. The problem with it would only be that it would be temporary and the user would only be able to see the output for a while.

How it works

So, how it works is pretty simple. The user chooses there letter by clicking the lever with the desired letter printed above it. The signal is then bussed to a whole bunch of D-flip flops. The user clicks save to trigger the save line of the line of d-flip flops. The user clicks next letter which triggers a counter, allowing the save line to be used on the next line of d-flip flops. Once the user has finished his/her word. The output is decoded into a 5×5 pixel character. Then, when the user presses “Print Single” or “Print Loop” pistons allow the decoder to send a pulse which is bussed to the pistons holding the water at the display. Dropping water in the desired sequence.

How this could be improved

This version is not as compact as it could be. I used 10 of the same decoders when I could have only used one. If you decode the input before you save the character, you can use only one decoder.
Another way this could be improved is by allowing full pictures to be printed. I am not going to further this project however, I have completed what I aimed for and am happy with the result. If anyone wants to go ahead and download my save to make their own waterfall printer. Credit for the idea is not required however it is a great pleasure. (:

So this is my second attempt in making this game. First was partly successful, because I went “old-fashioned” way: I’ve implemented CPU-like system, which was boosted by special designed hardware – in order for a snake to advance 1 step it took around 4-7 cycles of the machine. But because this machine was globally clocked, and clock speed is determined by longest datapath, the machine was pretty much slow.

Now in this design I used other technique, that is commonly used in video-processing chips: basic cell:

The game system consists of an array of such cells, which are connected to each other (each cell connects to 4 adjacent neighbors) . Because actual signal travel distance is determined only as distance from 1 cell to another, this system can achieve really great execution speeds – ensuring comfort play! (which is rare among redstone contraptions) All other signals, like change-direction or reset are delivered through insta-wire system (originally made by Shrogg), so there is no delay here. Basically, each cell acts like a “constructable road”  - and it builds up, as snake is moving, according to the current direction.

More detailed information on function of the cell you can find in a related forum topic here.

Less talk, more fun! Download the world, start the Minecraft! Start the snake by hitting Pause/unspause button, and take your position on the border between red/green wool. Your turning buttons will be on the sides. Snake will start moving upwards, and here you go. Note, that there is 5 tick delay between the actual game state and screen, so make your turns slightly before you need to turn If you loose, you will find detailed instructions on how to reset the game on the wall behind you. Have fun!

If you can’t play it right now, here is some demo video for you:

If you are new to the livestream, here are a few additional links to help clarify things:

Here is Version 1 of the project

Here is the original Prelude of the Chambered game written in Java by Notch

All the LiveStream episodes are available on my livestream channel or my YouTube channel

Thank you for joining me on this adventure!

while SOPA and PIPA moved on and received a lot of publicity, another, much worse law was made in the darkness, hidden from our eyes: ACTA. This law is a lot worse than SOPA. Unlike SOPA, ACTA does not only apply for America, but or Europe too.

This video explains ACTA very well.

Everyone should go take a look at that video. A picture is worth more than one thousand words, and a video contains many millions of pictures.

Sign up for this partition to protest against ACTA!

This weekend we are opening up our server to the masses!
If you want to see a persons specific plot, then go to /warp map, otherwise feel free to teleport to members to see what they are up to.
Note that we dont like people bugging us for info, so we would like it if all guests be polite to everyone, because Here at the RDF we like to have fun.

All guests will have access to the following commands:
/tp
/warp
/gm [gamemode]

SO:

As with everything i make it uses a slightly ‘different’ concept to other ram.

The way the RAM module works is by attaching an implies gate to an RS nor latch.

By use of careful timing between the B input of the implies (the input of the cell as a whole) and the A input (write signal of whole cell), and attaching the A input to the other part of the rs nor you can make a very compact memory cell which overwrites (unlike other designs).

Oh and it reads and writes in 2 ticks each

UPDATE: We’re already noticing the effect of SOPA and PIPA. The file sharing website Megaupload was just shut down without warning, and four of the people behing Megaupload is prisoned. This is really terrible. After the internet demonstration the 18th of january, they’re showing us the middle finger.

Today (the 18th of january), many popular sites like Wikipedia (the english version) and minecraft.net demonstrates against the bill SOPA, or Stop Online Piracy Act. The RDF server is also down today protesting.

SOPA is essentially a bill that will let U.S. Department of Justice take down sites with copyrighted content on them. This means that, in worst case, most forums and video sharing websites will be taken down.

YouTube got a lot of copyrighted content, and until now, it’s been the users who were responsible for their content. The users are doing an illegal thing by uploading copyrighted content. If SOPA passes, however, YouTube will be responsible – not the users. This means, in worst case, that if anyone uploads copyrighted contents to YouTube (like a part of a movie, or a soundtrack for a video), YouTube will be taken down.

This sounds terrible, right? Well, it’s even worse. It does not only happen if YouTube got any copyrighted content, but it’s the case with ALL websites. This is really terrible, but it is EVEN worse than that. It does not only affect America, even though it is an american bill. It affects the entire world.

You should definitely protest against SOPA.

Protest here: https://www.google.com/landing/takeaction/

More information about SOPA: http://en.wikipedia.org/wiki/Sopa

This video explains SOPA very well.

Do not let the american government ruin the internet! Protest!

https://www.google.com/landing/takeaction/

https://www.google.com/landing/takeaction/

https://www.google.com/landing/takeaction/