computer hacks

1431 Articles

computer hacks

Waterfall Swing Set

October 14, 2012 by 21 Comments

[Doped Boron] wrote in to tell us about this waterfall swing by [Dash 7]. Naturally, we had no idea what a “waterfall swing” was. Shown at the World Maker Faire in 2011, the device is a swing set capable of accommodating one or two people using it at a time. What makes it interesting, is that water comes out of the top support bar, forming a wall of water for the riders to pass through. This wall is then broken when the swing user flies through it making for a dry experience.

According to the article, 273 solenoid valves are used to control the wall of water. These solenoids are controlled by a computer with sensors that detect where the riders are in the air and what speed they are going. As with most good hacks, it may not serve a “grown-up” purpose, but a set would definitely make a trip to the park more interesting!

Be sure to check out the videos after the break. The first shows the swing in its traditional role, but the second may be even more interesting, showing full control of the swing solenoids for water writing! Continue reading “Waterfall Swing Set” →

Programming Tetris By First Building A Logic Gate, Then A Computer, Then…

October 11, 2012 by 25 Comments

Hone your fundamental understanding of computer systems by completing this online course called NAND to Tetris. The idea is to develop each fundamental unit that goes into making computer programs a reality. This starts with logic gates, which are put together into modules that eventually become a functioning computer. From there you need an operating system,  a compiler, and eventually you’ll be playing a game of Tetris which you programmed yourself.

It’s certainly not an easy journey, but if you have a computer at your disposal you should be able to make it all the way through the course. There’s a software suite which includes a hardware simulator so that the computer you’re building can be assembled using HDL instead physical components.

The concept is discussed in this TED talk given by [Shimon Schocken]. It is also embedded after the break and in addition to the NAND to Tetris project he shows off some self learning software on the iPad. To us it seems very much like the learning software [Neal Stephenson] envisions in the Young Lady’s Illustrated Primer from his Diamond Age novel.

Continue reading “Programming Tetris By First Building A Logic Gate, Then A Computer, Then…” →

Try Out Your Assembly And BASIC Skills With A ZX Spectrum Project

October 4, 2012 by 15 Comments

It can be really hard to warm up to coding in Assembly. But this tutorial looks to make it understandable and (almost) easy. It focuses on programming a game for the ZX Spectrum. But you won’t need the hardware on hand as you can just use the ZX Spin emulator as you work your way through the code.

Ostensibly this is a 30-minute tutorial but that’s a gross underestimate. We finished a cursory read of the tutorial and the building blocks are certainly clear and easy to understand. But we like to make sure we understand every line of code and plan to spread that out over the coming weekend.

The first chapter eases us into machine code by combining it with a bit of BASIC. You’ll see how to manipulate the ZX Spectrum memory and then pluck that value back out into the BASIC program. But once chapter 2 hits it’s pretty much all assembly from there on out. The nice thing is that as you go along you learn how the hardware works and there are quite a few references to pages in the manual so you can do some extra learning along the way.

[Thanks Mathilda]

Tri-mounted Monitors Using Strut Channeling (no Welding)

September 27, 2012 by 15 Comments

[Optec] want his own triple monitor setup built to his specifications. It turns out to have been a pretty easy project thanks to his mastery of stock materials. The image above is just a bit dim, but if you look closely you can see the strut channel which makes up the monitor frame.

When it comes to this type of metal strut material there’s a lot to choose from. [Optec] went with the half-slot format which provides a little bit of left and right wiggle room. This is important to get the edges of those monitors to butt up to one another. After making a pair of relief cuts he bent the channel in two places, using 45 degree brackets as reinforcement. The monitor mounts are made of MDF with countersunk holes to hide the bolt heads which connect it to the channel.

He figures the total cost of the mount was around $40. Seeing how easy it was makes us think we may never buy a commercial TV mounting bracket again. Of course if you’re more into woodworking there’s a tri-monitor project for you too.

[via reddit]

Retrotectacular: Time Sharing

September 17, 2012 by 26 Comments

It’s easy to forget the layer upon layer of technological advances that led to the computers we use today. But this look at the state of the art half a century ago does a good job of reminding us. Here [Fernando J. Corbató] explains the concept of Time-Sharing. He is one of the pioneers of the topic which is now used in every computer system in the world.

Since processors (read: a single core) can only work on one operation at a time, it inherently creates a bottle-neck. This is a huge issue when you consider the cost of the computers used at the time. In the video he mentions $300-$600 an hour. That was in the 1960’s and would roughly equate to about $2300-$4600 in 2012. In other words, there’s big money in using the machine as efficiently as possible.

Early on in the discussion he mentions how programs were loaded and solutions were returned by computers of the day. It started with punch cards, then moved to magnetic tape. At the time this was filmed they had just started using teletype and were hoping to add a graphical interface in the near future. We’ve come a long way but the core principles he’s explaining are still quite important. See both parts of the film after the break.

Continue reading “Retrotectacular: Time Sharing” →

Building A Turing Machine From Magic The Gathering

September 12, 2012 by 8 Comments

If you really know your Magic the Gather and you’re a programming wiz you’ll appreciate this paper on building a functioning Turing Machine from Magic the Gathering cards. We’re sure you’re familiar with Turing Machines, which uses a rewritable strip to store and recall data. Most of the time we see these machines built as… machines. For instance, this dry-erase marker Turing Machine has long been on the top of our favorites list. But as The Diamond Age by Neal Stephenson illustrates, there’s more than one way to skin this cat.

A complete list of the cards used in this machine can be found here. A little bit of preparation (casting to tweak abilities) goes into making sure the cards will work as called for in the Turing design. The tape is made of Ally tokens to the right of the head, and Zombie tokens to the left. The computational abilities of the head depend on the colors of the cards. It’s a bit too complex to paraphrase, but the design is based on this 2-state, 3-symbol setup whose rules are listed in the image above.

It’s going to take us a while to fully wrap our heads around this thing, but it’ll be fun getting to that point!

[via Slashdot]

Breadboarding A 4-bit ALU

September 10, 2012 by 8 Comments

[TGTTGIT] recently took the plunge and decided to build his own computer using logic chips. He just completed a 4-bit ALU which can compute 18 functions. It took a long time to get the wiring right, but in true geek fashion his build was accompanied by an alternating Chapelle’s Show and Star Trek: TNG marathon playing in the background.

This project is the stepping stone for a larger 16-bit version. The experience of wiring up just this much of it has convinced him that an FPGA is the only way to go for the future of the build. But since he had already ordered the chips it was decided that the only thing to do was to see this much through. He used the truth table from The Elements of Computing Systems for the design and posted several times about the project before arriving at this stopping point so you may be interested in clicking through the other post on his blog. There’s also a lot of other TTL computer projects around here worth checking into.

Continue reading “Breadboarding A 4-bit ALU” →