Secret C64 Program Found On A Christian Rock Band’s Vinyl Record

November 24, 2019 by Sharon Lin 29 Comments

How often do you find Easter eggs in old vinyl records?

It sure was a surprise for [Robin Harbron] when he learned about a Commodore 64 program hidden on one of the sides of a record from the 1985 album of Christian rock band Prodigal. The host of the YouTube channel 8-Bit Show and Tell shows the “C-64” etching on one side of the vinyl, which he picked up after finding out online that the record contained the hidden program.

The run-out groove on records is typically an endless groove that keeps the record player from running off the record (unless there is an auto-return feature, which just replays the record). On side one of the vinyl, the run-out groove looks normal, but on side two, it’s a little thicker and contains some hidden audio. Recording the audio onto a cassette and loading it onto a dataset reveals a short C64 program.

The process is a little more troublesome that that, but after a few tries [Harbron] reveals a secret message, courtesy of Albert Einstein and Jesus Christ. It’s not the most impressive program ever written, but it’s pretty cool that programmers 35 years ago were able to fit it into only a few seconds of audio.

Unfortunately, we won’t be hearing much actual music from the album – [Harbron] chose not to play the songs to avoid copyright issues on YouTube.

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Speeding Up IOTA Proof Of Work Using FPGAs

November 16, 2019 by Sharon Lin 5 Comments

Blockchain has existed as a concept since the early 1990s, but keeping a distributed ledger for IoT transactions wasn’t widely implemented until IOTA developed Tangle. The blockchain company was initially founded as a hardware startup and pivoted to work on transactional settlement for IoT. The Tangle, their distributed ledger architecture based on a directed acyclic graph (DAG) works as a “blockchain without the blocks and the chain”.

As its name implies, the Tangle is a web of transactions that references its past two transactions and a subsection of other transactions. Rather than miners and stakers being responsible for overall consensus, all active participants are involved in the approval of transactions. The transaction process requires the client to sign with their private keys, select two random unconfirmed transactions to be referenced, and perform proof-of-work.

The proof-of-work has an unfortunately high difficulty as you might expect. The process is similar to finding a nonce in Bitcoin mining, although the difficulty is set at a lower threshold due to the transactions running on lower-power nodes. Even so, since IOTA transactions commonly occur on small embedded platforms this can take several minutes to complete, a relatively long time considering these are mere transactions.

Since Curl-P81 hashes should be computed in parallel, they can’t be computed efficiently on general purpose CPUs. The PiDiver 1.3, [Thomas Pototschnig]’s port of the IOTA Reference Implementation (IRI) PearlDiver, performs searches for nonces. Because it runs on FPGAs, it is able to speed up the proof-of-work by a factor of more than 140 when compared to a Raspberry Pi. The FPGA is able to calculate one round of the hash in a single clock cycle, and a complete hash in 85 cycles (as well as testing for a valid nonce). Seven parallel hashes can be calculated at once, giving 15.8MHash/s at a frequency of 188MHz. The proof-of-work takes ~300ms on the FPGA when compared to 90s on a Raspberry Pi, so this is a significant improvement in speed.

Since the project is open source, the core can be used by IRI for creating a modified version of their PearlDiver. The board can be used as a Raspberry Pi HAT, although it can also be connected via USB to work without the Pi.

While this doesn’t address the security concerns of using IOTA with personal IoT devices, it is certainly a significant improvement on the speed of their proof-of-work process, and the software speedup is incredibly satisfying to watch.

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A Simpler Method To Make Optical Fiber With 3D Printing

November 5, 2019 by Sharon Lin 11 Comments

There are a lot of remarkable uses for optical fiber, chief among them being telecommunications and imaging. While fiber can be produced for a better price than copper wire equivalents, they’re still not easy or cheap to manufacture.

Silica fibers require spinning tubes on a lathe, which requires the fiber’s core to be precisely centered. A new method by researchers based at the University of Technology, Sydney offers a simpler method using additive manufacturing.

There are still challenges in producing silica fiber, however – unlike commonly drawn polymer materials, silica requires high temperatures, up to 1900 degrees Celsius, to 3D print. Past attempts at glass printing using fused deposition modeling with high-temperature nozzles to pump out molten silica have been slowed by the viscosity of molten glass.

In order to overcome the temperature problem, composite materials consisting of a polymer with a lower melting point and silica nanoparticles are used instead. In addition, the researchers opted to use a direct laser writing printer. The technique involves drawing the molten material and pulling out the optical fiber. After the polymer and impurities are debinded and removed, it’s only an issue of sintering the silica to fuse the forms back together.

The method has been used to fabricate a preform that can be used for multi- or single-node fibers. While the technique isn’t perfected quite yet, it holds promise for reduced fabrication and material costs, as well as eliminating labor risks from the lathe-based work.

[Thanks to Qes for the tip!]

A New Method For Growing Watch Springs

November 2, 2019 by Sharon Lin 26 Comments

Scientists at the Swiss Federal Laboratories for Materials Science and Technology (Empa) recently developed a new technique for growing watch springs to tiny specifications. As it turns out, the creation of watch springs is ripe with opportunity for new materials research.

The technique involves using photo-etching and electrochemical deposition into cold, aqueous solutions. Compared to drawing and winding Nivarox wires, this is a fairly unconventional method for manufacturing. For as long as watchmaking has been around, creating the balance springs has been one of the most difficult parts of the job. The wires must be drawn to a thickness in the hundredths of millimeters and wound and tempered to the exact hardness, ductility, and elasticity while compensating for environmental factors. Many substances change their properties during fabrication, so the Empa team decided to look to pure materials research as a way to find a means for fabricating balance springs that would remain stable.

They took silicon wafers (the same kind used for solar panels and computer chips), covered them in gold and a thin layer of light sensitive paint, and etched the shape of a spring into the wafer. The wafer was then dipped into a galvanic bath containing a salt solution from a metallic alloy — the spring acts as a cathode so that when an electric current passes through the bath, metal is deposited at the base of the spring. Once the spring is built up, it is dissolved from the mold and examined. After a bit of smoothing, the final spring is washed and sent to a lab for prototype production.

The electroplated springs are currently on display at the Laboratory for Mechanics of Materials and Nanostructures at the Empa campus in Thun, Switzerland. In the meantime, the first pilot tests are being wrapped up, and the team is beginning to work with Swiss watchmakers to see if their springs can hold up inside watch mechanisms.

[Thanks to Qes for the tip!]

These Maple Pod Inspired Drones Silently Carry Payloads

November 2, 2019 by Sharon Lin 15 Comments

Researchers from the Singapore University of Technology and Design (SUTD) recently released a video showing their nature-inspired drone that is capable of breaking out into five separate smaller drones. The drones each have auto-rotating wings that slow their rate of descent, similar to seed pods from a maple tree. Due to their design, the drones are only made to be used for a one-way trip, with the five components each carrying a separate payload. The drones are designed to detach within a specified distance from their destination, allow the collective body to safely spiral downwards towards land.

In their paper published on the same subject, the researchers discuss how they optimized the balsa wood wings with servos, a LiPo battery, and a receiver attached to a 3D-printed body. Four are equipped with just these components, while the fifth also holds a 3-axis magnetometer, a Teensy 3.5 board, a GPS module, and a Pixracer controller.

They experimented with several motion capture setups and free-flight drop tests to verify their simulations on the models for the drones. Apart from simply detaching, they are also designed to cater to different mission profiles based on the environment they are dropped in.

We’ll admit that the implementation and design of the drones does seem fairly dystopian, especially when you wonder what could possibly be the payloads these drones are designed to carry. But in terms of nature-inspired robotics, the maple seed pod idea is pretty interesting.

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An All-Electric Plane Takes To The Skies

October 27, 2019 by Sharon Lin 89 Comments

With climate protests and airline strikes occurring around the world, there is more awareness than ever before for the necessity of environmental sustainability. More importantly, there is more discussion around the immense carbon footprint left by the airline industry, perhaps one of the largest contributors to climate change worldwide.

The Slovenian-based Pipistrel ALPHA Electro is one of the leading electric planes today, with bragging rights as the world’s first mass-produced electric aircraft. While NASA may have announced their X-57 Maxwell, the plane is still undergoing testing for its first planned flight in 2020. The ALPHA Electro, marketed as a trainer plane for flight students and recreational flyers, features a 34’6″ wingspan and low running costs.

The two-person flyer is equipped with a 60 kW electric motor, with a cruising speed of about 157 km/hr. A 21 kW battery provides the plane with enough energy for a 55 minute flight, with a half hour reserve, and takes about an hour to charge back up. An additional perk of flying an electric plane is the low noise and zero CO2 emissions, which allows the flights to take place near large cities with exhaust and noise emission standards.

With airplanes, a majority of the fuel is used for takeoff and landing, making short haul flights particularly troublesome – compare 107 lbs CO2 flying from New York to Boston versus 62 lbs CO2 driving. While refraining from frequent flights is still the best idea for reducing your carbon footprint, we’re hopefully headed towards more environmentally-friendly options for air travel.

Check out the ALPHA Electro’s teaser video below.

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Building The World’s Best DML Speakers For Under $115

October 26, 2019 by Sharon Lin 33 Comments

Flat panel speakers are heavily reliant on the material they’re mounted on for the best acoustic quality. In particular, for DML (distributed mode loudspeaker) speakers, sound is produced through the distribution of vibration modes in the panel. You can easily spend far too much on special exciter foam or optimized materials for producing the best quality sound.

[Tech Ingredients] does a deep dive into how to build high-quality and low-cost DML speakers using some interesting materials, such as acoustic ceiling tiles and styrofoam. He analyzes their frequency based on the material and shape used and demonstrates how a full setup sounds with studio microphones and stereo speakers installed. The shapes can allow the resonances for different speakers to be translated so that they don’t overlap – peaks can be matched with troughs to produce a more even sound. Squares with rounded edges work the best for translating the resonance.

Balsa wood is mainly used for low frequencies and styrofoam for high frequencies, although the ceiling tiles work as well as either material and are significantly cheaper. Rather than retrofitting into drop ceiling metal frames, he instead installs his panels vertically. He shows the process for preparing the styrofoam and ceiling tiles for hanging, including tips for creating a makeshift circular saw for punching out holes and securing cotter pins with epoxy.

[Tech Ingredients] goes through experimenting with unusual shape and material combinations in order to produce the best possible speakers. It’s a fascinating video that walks through the ins and outs of DIYing your own set of speakers, and it’s worth a watch even just to hear about the acoustic properties of materials.

[Ed Note: Yes, this video is a bit long in the tooth, but we keep getting tips for it, so it’s news to someone! And it’s cool regardless. But feel free to skip on if you’ve seen this one before.]
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