TechyMagThings

Before the past year, many of us took computer memory for granted. It was one of the lower-cost parts of a PC build and was usually available in whatever quantity one desired. As its cost has skyrocketed, a lot of PC builders and other users of computers in general are taking a deeper look at memory, how much is really needed, and what its functions truly are. [Igor] is working on a drum sequencer project which needs a small amount of memory, and has built this dynamic RAM from discrete components.

The first video goes into the construction of the memory array and how its addressed. It’s only eight bytes total, and using fairly large electrolytic capacitors to store data means that a gigabyte of this memory would take up well over a thousand acres, but it’s still enough memory for [Igor]’s needs. In addition to the capacitor, each bit uses a pair of diodes to determine if a read or write is occuring, and a set of transistors on the read and write busses to perform those actions. Worth noting here is that dynamic RAM like this needs to be refreshed because the capacitors lose charge over time, but these large capacitors can hold charge sometimes overnight, as [Igor] has confirmed experimentally.

There’s a followup video to the construction of these modules as well, where [Igor] demonstrates a number of ways this module can be used, from controlling LED arrays, 7-segment displays, and then installs it into his drum machine. With 64 bits available it’s capable of creating up to eight beats with eight samples available per beat. Although there are complete machines available for all of this, we appreciate his goal of not buying any pre-manufactured hardware and instead constructing it all from the ground up. There are analog drum machine options available in this same style as well.

While there is a time and place for wirelessly controlled devices, sometimes you want something you can just reach out and touch to interact with, no apps to install or devices to configure. In this case [John] wanted a lamp that was just that. Drawing inspiration from the rotary phone, he created the LightComposer.

This small lamp, just a bit smaller than a hockey puck, uses a 3D printed enclosure and a straightforward PCB. It’s a very accessible project to recreate. The 3D prints are well thought out including a TPU ring on the bottom to keep the lamp from sliding around. The light source comes from 32 SK6812 LEDs, which are very similar to NeoPixels. An ATmega328P microcontroller powers the project and can easily be programmed using the Arduino IDE. A rotary encoder in the center, coupled to the top diffuser, lets you control LED brightness and color by turning it. The firmware also includes some fun hidden light-effect modes.

Head over to [John]’s site for all the files needed to make your own LightComposer, or links to buy a premade one. What devices have you made that use a straightforward physical user interface in lieu of an app? Be sure to check some of the other lamp builds we’ve featured before.

After recently publishing a few videos covering research into the poor adhesion between chopped carbon fiber (CCF) and the thermoplastic filaments as used with FDM 3D printing, some of the feedback received by [I built a thing] included the idea that the missing step to make CCF additives work was post-print annealing. Naturally this claim had to be investigated, both through the resulting physical characteristics as well as on a microscopic level in the same scanning electron microscope (SEM) as before.

Theories as to why annealing the parts would help here seem to focus on increased bonding and filling of voids in the printed CCF-infused material, while there are the typical worries with annealing such as parts warping and shrinking to also take into account as potential downsides of this treatment.

For the sample materials PETG and PETG-CF, as well as PLA and PLA-CF filaments are used, with each filament type featuring an annealed and not annealed version. These were then tested for tensile strength, stiffness and failure type, as well as dimensional accuracy and warping, before being examined under the SEM. A total of 160 samples were used, with 20 samples per material and annealing state.

Perhaps the biggest surprise here was how much PETG benefits from annealing, making it much more resilient to breaking, whereas neither PLA nor PLA-CF seemed to see much benefit. Shocking was how much worse PETG-CF performs than PETG, with the former being worse than both PLA and PLA-CF here.

In terms of dimensional accuracy, annealing caused a Z direction expansion while shrinking the samples in the  other directions. The CCF addition here actually prevented much of the shrinking and expansion, showing the first clear benefit of this additive. Yet despite annealing at right above the glass transition temperature as is proper, this would seem to be the limit of this approach in terms of practical benefits.

Compared to the previous research that focused on PLA-CF, PETG-CF would seem to make the case even more strongly that there’s no real purpose to CCF additives, especially since you can already account for parts shrinkage during annealing before printing. That there’s no improvement to the CCF and thermoplastic interface adhesion is also no mystery, considering the science behind how e.g. thermoset materials create bonds with CF.

Usually the term ‘jailbreaking’ isn’t meant to be taken quite that literally, but in the case of the US prison tablet that [Hugh Jeffreys] got sent, it’s really quite apt. Unlike the typical transparent prison electronics, this tablet is hermetically sealed inside an opaque plastic case, with the Windows 10 install firmly locked-down and not allowing anything more to be done with it than access some prison-provided services via the browser in kiosk mode.

The first challenge was to see whether it could be booted at all, with just four metal pads visible on the side of the case. These turn out to correspond to USB pins, but the tablet only briefly tries to turn on with a charger connected. This means that a teardown is required, which ended up involving a hacksaw due to the sealed case.

Inside the case is the Windows tablet with the back cover removed, presumably for easy access to extend its USB port. All of this is embedded in foam and more gunk that makes disassembly rather messy. With the case opened it becomes clear that the likely reason why this tablet was junked was due to a bad third-party charger board, as using the tablet’s own USB port it charges happily and even turns on.

From there it’s a bit of a fight with the locked-down Windows installation, but as it’s just a Windows 10 Home installation, there’s no drive encryption or such to get in the way. This allows for the device to be fully jailbroken, revealing its specifications as an Iview Optimus-C-8001, powered by an Intel Atom Z8350 at 1.44 GHz with a blistering 2 GB of RAM. The Windows installation was from 2018, with apparently no updates since.

Despite the very high school arts-and-crafts appearance of the case itself, the tablet itself isn’t too shabby considering the limited hardware specifications. Although getting the case off is a bit of a pain, it’s not a bad catch if you can find one of these puppies in the e-waste bin.

The British government is in a headlong rush to ban under-16s from social media, and restrict the access of under-18s. And in typical form, the EFF is here with a warning about the dangers and futility of such legislation.

The proposed new law will involve an age restriction policed through online ID verification, something which will not be limited to the young, as every British adult will also have to show ID to access large parts of the Internet.

There is little in the way of information about how this unprecedented invasion of privacy will be implemented, however we expect that it will be left to the lax security measures of a range of lowest-bidder third party identity verification services. The resulting database will become a very rich target indeed.

The EFF pull no punches in warning of the harms these measures will bring upon those it seeks to protect. Far from “Giving under-16s their childhood back” as it is being promoted, they warn that it will deprive them of access to community, friends, and distant family, as well as educational content that could be vital for them.

If it works at all. Certainly he more technically minded youth will put their efforts into the world of computer networking. A VPN ban is reportedly in the works, so a whole generation of future software developers and IT specialists will get their start running software to get round this on their Raspberry Pi.

We’ve reported on the EFF’s concerns over UK ID laws before.

Header image: Diliff, CC BY-SA 2.5.

There are as almost as many kinds of coffee as there are of coffee drinkers, with each method for preparing the beverage appealing to a different kind of palate: moka pots, filter coffee, pour-over coffee, French presses, cold brews, espresso, and more produce their own unique flavours by extracting different compounds from the grounds to different degrees. Now, a new method has joined the throng: ultrasonic-assisted extraction, which can produce even an espresso at room temperature.

Espresso is normally made by forcing hot water through tightly-packed, finely-ground coffee beans, quickly producing a concentrated extraction. Its one of the hardest kinds of coffee to consistently make well, since the outcome is influenced by everything from grind size and packing density to temperature, pressure, and more. Ultrasonic agitation helps here by creating cavitation bubbles, which form shock waves as they collapse, breaking open the bean structure and producing small, strong jets of water. The experimental apparatus was built into a modified espresso machine. An ultrasonic transducer delivers vibrations to the basket containing the room-temperature slurry of coffee grounds for two or three minutes.

To quantify the results, the researchers analysed total dissolved solids, extraction yield, pH, colour, volatile components, and caffeine and chlorogenic acid contents. By varying ultrasonic power and grind size, the extraction yield and dissolved solids could be adjusted to closely match traditional espresso or cold-brew coffee. The other metrics had no significant differences, and a survey of 100 coffee drinkers found no preference between this and traditional espresso. When the drinkers tried the cold-brew coffees, they preferred the version made with ultrasonic assistance. The experiment succeeded in its goal of reducing energy consumption: the ultrasonic-assisted coffee took about a quarter as much power to make.

If you still prefer a more traditional approach, we’ve covered some beautiful espresso machines before, including one made out of motorcycle engine parts.

Today marks the summer solstice, the longest day of the year and the start of astronomical summer in the Northern Hemisphere. This doesn’t really have much to do with hacking hardware or building gadgets other than the fact that from this point on you’ll have progressively less daylight hours to do it in each day. Of course, if you do your best work in the middle of the night this won’t impact things much.

If you’re as likely to find a controller in your hand as a soldering iron in the evenings, you might be interested in a recent filing against Sony. Lawyers representing a group of four gamers allege that the entertainment giant is violating a California law that says digital storefronts need to make it clear that buyers don’t technically own the games in question but are merely licensing them — a license which, as we’ve seen in the past, can be revoked or modified at any time with no restitution made to the purchaser.

Now while we agree conceptually that selling gamers a license rather than an actual copy of the game is clearly a one-sided deal, we’re still not sure this case has a lot of merit. As far as we can tell, Sony does make it clear in the fine print that you’re not really going to own anything once they take your money. Or, at the very least, they make it equally as clear as any other company that’s selling digital downloads these days. Should the court actually find that said fine print is a little too fine, it could conceivably have ramifications throughout the entertainment industry. This is certainly a case to keep an eye on.

If you want to be sure none of your games can be removed from your digital grasp without warning, perhaps your best bet is to stick to the classics. Fans of 1989’s F-15 Strike Eagle II on PC will be excited to hear that there’s an ongoing effort by Neuvieme Porte to reverse engineer the flight sim and re-implement the whole thing in portable C.

This would open up all sorts of possibilities, such as ports to other platforms and the addition of new features and content. But before the project can get to that point however, Neuvieme is looking to recruit some virtual test pilots. Just keep in mind that the goal, at least for now, is to recreate the game exactly. That means bugs present in the original release are to be preserved. As such, it would help to have logged enough hours back in the DOS days to recognize what’s an OG bug and what’s been newly introduced.

From working on virtual jet fighters to the real deal, IEEE Spectrum recently ran an article about a startup called Phoenix Semiconductor that’s looking to produce bespoke pin-compatible replacements of critical chips for the military. They reason that the Air Force won’t mind paying $1,000 for a chip that cost them a buck back in 1975 when the alternative is grounding a $70+ million F-18 that needs the thing to take off. The goal isn’t really to recreate the old parts as they were, but instead to build drop-in replacements that are tailored for specific applications. In other words, Uncle Sam doesn’t care of the IC actually looks like the original, so long as it fits and it gets the jet up in the air again.

Finally, on the subject of aerospace technology, NASA’s Jet Propulsion Laboratory published a blog post earlier this week detailing their work on the Exploration Rover for Navigating Extreme Sloped Terrain (ERNEST). While NASA’s Curiosity and Perseverance rovers have done some incredible work on Mars, they’re slow and have to be operated with the utmost caution to make sure they don’t get stuck. In comparison, ERNEST is several times faster and is designed with an active suspension system that lets it lift each wheel up off the ground independently if needed.

The prototype rover also features improved autonomy that may allow future rovers make more decisions on their own. That may not be a huge time saver on the Moon, but given the communication delays with the Red Planet, a Mars rover that doesn’t have to stop and ask Earth for directions so often will be able to get more useful work done at the end of the day.

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