Converting A Flip-dot Display To Work Like Core Memory

flip-dot-display-as-core-memory

It’s always interesting to see what will come out of a hacker meet-up. At the Observe, Hack, Make festival earlier this month [Bertho] was talking to a guy named [Erik] about how flip-dot displays work. [Erik] mentioned that the control theory is the same as core memory. So when [Bertho] got back to his home workshop he started playing around with it to see if a flip dot display can be made to behave exactly like core memory.

We’re really glad a successor to core memory was found since it’s pretty slow. But the concept still makes for some fun exploration (here’s the obligatory Arduino implementation of core memory). It uses magnetic rings with two conductors running through them that pass at right angles to each other. Sound familiar? This is exactly how flip-dot displays work.

There are, of course, some differences. The biggest one being that the displays don’t have the sense wire present in core memory. That was an easy enough thing for [Bertho] to get around. He added the grey sense wire by threading it through the inside of the hardware. The other hurdle he had to overcome was to alter the controller firmware to match the destructive tendency of core memory (reading the state also resets it).

So far he’s just set this up as a proof of concept, reading the sense wire while repetitively reading and writing to the “memory”. But it’s engaging to see what was captured on the scope. We asked him about his future plans, specifically what he would use to automatically read from the sense wire. His response is found after the jump.

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0x10c Becomes A Community-developed Game

0x10c

It’s official. [Notch], creator of Minecraft, has confirmed he’s shelved plans for 0x10c, the space-based block building and exploration MMO that features assembly programming as a core game component.

Over the last year or so since 0x10c was announced, a whole lot of programmers have picked up the in-game fictional CPU – the DCPU – by writing emulators and even emulating this CPU that only exists as a design document on an AVR. Needless to say, there are a lot of very skilled programmers that want this game to exist. Now, it seems, this community is forging ahead with this project without [Notch].

This is a truly massive undertaking by the community. Not only are the current plans to build an open world, procedurally generated, space-based MMO, it looks like these new developers will also be writing their own engine from scratch. If this were a commercial endeavour, it would require millions of dollars and many years to get to a rough alpha build, and the 0x10c community is doing this for free.

If you have experience in C++, OpenGL, and 3D game programming, the official signup thread is over on the 0x10c subreddit. Even if you’re not a programmer and only have experience in modeling, writing, your experience would be greatly appreciated.

Hacking Transcend Wifi SD Cards

[Pablo] is a recent and proud owner of a Transcend WiFi SD Card. It allows him to transfer his pictures to any  WiFi-enabled device in a matter of seconds.

As he suspected that some kind of Linux was running on it, he began to see if he could get a root access on it… and succeeded.

His clear and detailed write-up begins with explaining how a simple trick allowed him to browse through the card’s file system, which (as he guessed correctly) is running busybox. From there he was able to see if any of the poorly written Perl scripts had security holes… and got more than he bargained for.

He first thought he had found a way to make the embedded Linux launch user provided scripts and execute commands by making a special HTTP POST request… which failed due to a small technicality. His second attempt was a success: [Pablo] found that the user set password is directly entered in a Linux shell command. Therefore, the password “admin; echo haxx > /tmp/hi.txt #” could create a hi.txt text file.

From there things got easy. He just had to make the card download another busybox to use all the commands that were originally disabled in the card’s Linux. In the end he got the card to connect a bash to his computer so he could launch every command he wanted.

As it was not enough, [Pablo] even discovered an easy way to find the current password of the card. Talk about security…

All Wheel Drive Motorcycle

Take one look at the front fork of this dirt bike and you’ll notice that it’s not really a front fork at all. A custom front end replaces the traditional design in order to give this motorcycle all wheel drive. Look closely and you’ll see the chain that drives the front wheel. The swing-arm like addition lets the front end retain all of its suspension and steering and that’s where the project gets tricky.

We actually saw this thing in person at the monthly meeting of our local hackerspace: Sector67. [Martin Lawson] got his seven minutes of fame during the presentations (they use a prototype of this scoreboard to limit each presenter), and then was mobbed with a ton of interest afterwards. We were able to get a pretty good look at how the front drive works. It starts with an additional cog fastened beside the one that drives the chain for the back end. This feeds up through some tensioners and transfers out on the left side (from the rider’s perspective) of the front end. From here the rotational force is transferred to the right right and includes a U-joint to account for steering. The last chain goes straight down to the wheel.

The idea is that when the rear wheel loses traction you’re still being pulled by the front. This is illustrated well in the video after the break. [Marty] — who has a patent on the design — is trying to get some interest from manufacturers. He says the ability ride right through poor traction terrain make this a lot easier than a traditional dirt bike for beginners to ride. But it’s obvious the professionals are having fun on the thing as well!

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An Elegant Timepiece From Paper And A Fistful Of Servos

papercraftClock

Segments rise from a sheer white surface to reveal the time in this papercraft digital / analog clock build by [Jacky Mok].

New York-based designer [Alvin Aronson] is responsible for the original, titled “D/A Clock,” which he built as a student at RISD using Corian instead of paper. [Aronson]’s design is also massive in comparison. It measures one meter wide by a half meter tall. Without access to either a 3D printer or to a laser cutter, [Jacky] instead reduces the scale of his interpretation and relies on cardstock as the primary construction material. His experience with papercraft typography leads to a design that anyone with an Exacto knife and a slice of patience should find manageable. [Jacky] ignores the Exacto option, however, and cuts his pieces with a tool we saw earlier this year: the Silhouette Portrait.

The clock’s electronics include an Arduino Uno, a servo motor controller, twenty-eight servos and an RTC breakout board that handles timekeeping. Each servo drives its own segment by sliding a paperclip forward or backward inside a small, hollow aluminum rod. Though we’re still holding out for a video of the finished papercraft build, you can watch a video of Aronson’s original clock after the break and see what inspired [Jacky’s] design.

Need another clock to envy? Last month’s build by [ebrithil] uses twenty-two servos to individually spin the segments. If you prefer that your clocks light up, [Aaron’s] o-scope transformation has you covered.

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Hack VersaPak Battery Modules To Reuse Laptop Cells

retrofit-battery-packs-with-laptop-cells

If you’re familiar with VersaPak tools you’ll note that while the battery pack in this image looks somewhat familiar, it’s not supposed to have a removable cell. This is [Martin Melchior’s] hack to use laptop 18650 Lithium cells with VersaPak tools.

The original NiCad packs used three cells for a total of 3.6V, so it is possible to substitute a Lithium cell in the same voltage neighorhood. The tools are pretty hard on the battery packs, drawing a lot of current in certain situations. But these cells are being harvested from dead laptop battery packs so it’s not a huge concern if their life is a bit shortened.

The hack places an 18650 battery receptacle inside of the VersaPak battery housing. There’s a bit of careful disassembly to get to this point, but it’s well illustrated in [Martin’s] project log. And of course you’ll need to use a proper Lithium battery charger from here on out.

This form factor has been popping up in a lot of hacks lately. Here’s another one that modifies the Goal Zero Bolt flashlight to use them.

Boominator Solar Stereo Keeps The Music Pumping Even In Cloudy Weather

Despite 40-some years of product improvements, boomboxes today still require a half dozen D-cell batteries and measure their life in single digit hours.  After this, the batteries get chucked in the trash. Tired of the absurd cost and quantity of batteries required in a typical boombox, reddit user [anders202] has whipped up a solution that will keep the party going and the landfills empty. Using some off-the-shelf components and some impressive woodworking skills, he created the “Boominator”.

Despite its environmentally-conscious design, this green machine packs a whallop. Using its dual 10W solar panels, it can drive four woofers and tweeters to produce an estimated 102dB of sound with power to spare.  This extra juice can be used to charge its two internal 7.2Ah batteries or a cellphone using the integrated USB charging ports.  Better still, Anders chose amorphous solar panels (as opposed to crystalline) which produce power even in cloudy weather as demonstrated during a cloudy day at the Roskilde festival in Denmark.  For more information, check out the reddit comment thread.

Video demo after the jump

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