Build Your Own Bootable Emacs Environment

April 22, 2023 by Bryan Cockfield 18 Comments

An old joke is that Emacs is a text editor with an operating system included, given that its extensibility and customization often goes far beyond traditional text editors. Part of its well-earned reputation comes from being built in Lisp which allows it to be expanded to do almost anything. Despite this in-joke in the community, though, you will still need an actual operating system to run it, but not much more than that.

This project uses User-Mode Linux (UML) as a foundation to load almost nothing other than an Emacs editor. UML is a virtualization technology that allows running multiple Linux kernel instances as separate virtual machines, so once the Linux environment is started and Emacs is compiled, the virtual machine can essentially boot straight into an Emacs environment. Some tools are needed outside of the Linux kernel like mount which allows the virtual file system to access the files needed to build Emacs, but as far as lightweight or minimalist Linux distributions go this one definitely gets at least an honorable mention.

While UML is virtualization software rather than a full-fledged Linux distribution, we would expect a similarly minimalist build could easily be done with something more hardware-based like Linux From Scratch. Emacs has been around for so long and had such a wide reach that it’s difficult to imagine a world without it. Even in more modern technology like browsers, knowing a little bit about Emacs can be an extremely powerful tool.

The Freedom To Fail

April 22, 2023 by Elliot Williams 38 Comments

When you think of NASA, you think of high-stakes, high-cost, high-pressure engineering, and maybe the accompanying red tape. In comparison, the hobby hacker has a tremendous latitude to mess up, dream big, and generally follow one’s bliss. Hopefully you’ll take some notes. And as always with polar extremes, the really fertile ground lies in the middle.

[Dan Maloney] and I were thinking about this yesterday while discussing the 50th flight of Ingenuity, the Mars helicopter. Ingenuity is a tech demo, carrying nothing mission critical, but just trying to figure out if you could fly around on Mars. It was planned to run for five flights, and now it’s done 50.

The last big tech demo was the Sojourner Rover. It was a small robotic vehicle the size of a microwave oven that they hoped would last seven days. It went for 85, and it gave NASA the first taste of success it needed to follow on with 20 years of Martian rovers.

Both of these projects were cheap, by NASA standards, and because they were technical demonstrators, the development teams were allowed significantly more design freedom, again by NASA standards.

None of this compares to the “heck I’ll just hot-air an op-amp off an old project” of weekend hacking around here, but I absolutely believe that a part of the tremendous success of both Sojourner and Ingenuity were due to the risks that the development teams were allowed to take. Creativity and successful design thrives on the right blend of constraint and freedom.

Will Ingenuity give birth to a long series of flying planetary rovers as Sojourner did for her rocker-bogie based descendants? Too early to tell. But I certainly hope that someone within NASA is noticing the high impact that these technical demonstrator projects have, and also noting why. The addition of a little bit of hacker spirit to match NASA’s professionalism probably goes a long way.

NFC Antennas Have Other Uses

April 22, 2023 by Jenny List 38 Comments

As NFC chips proliferate, so do the antennas they require for operation, and since many NFC-enabled items are single-use, this means there’s an opportunity to put them to other uses. It’s an avenue pursued by [Brother-live], as he strips the antennas from spent metro tickets and gets experimenting.

The antenna in an NFC-enabled card is a flexible PCB laminated between the plastic outer layers, with the tracks forming a coil round the outside of it. Using some solvent the cards can be easily separated and the antennas retrieved. Once the chip has been removed they can be cleaned up and soldered to, allowing wires to be connected.

What can you do with an NFC antenna? Not a huge amount as you can see in the (Russian language, English subtitles) video below the break, but he tries it as a not-very-good heating pad, a power harvesting antenna from NFC readers, and perhaps most promisingly, as the coil of a moving-coil speaker. We’re not sure how much effort would be worth making on that last front, but we think with a bit of care there might be room for audible improvement.

If you’ve ever been tempted to have a look at an NFC card, it’s a subject we’ve covered before.

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Air Hockey Solitaire

April 22, 2023 by Al Williams 3 Comments

While air hockey is a fine amusement, it isn’t much fun if you can’t find someone to play against. Unless that is, you build a mini table with a robotic defender. [Vaib], [Nathan], and [Navish] can show you how. There is a video you can see below that shows two players using the table without the robot.

The project takes a bit of woodworking, as you might expect. You also have to drill 576 holes for the air to lift the puck. Some of the components are 3D printed in PETG, too. The automated defense uses a camera and relies on the fact that the puck is the only red thing on the table. A servo moves to intercept the incoming puck and return the shot. We were disappointed the video didn’t show the automated play.

We wondered if they had considered making a pair of the detachable robots and letting them play with each other. If you prefer football, the robot could probably adapt. We’ve seen other robot air hockey contenders, so maybe a better idea would be to build different robots and let them compete for a gold medal.

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Before You Sudo Rm -rf /, Take Some Precautions

April 21, 2023 by Bryan Cockfield 40 Comments

Maintaining or administering a computer system remotely is a common enough task these days, but it’s also something that can go sideways on you quickly if you aren’t careful. How many of us are guilty of executing a command, having it fail, and only then realizing that we weren’t connected to the correct computer at all? [Callan] occasionally has this issue as well, but in at least one instance, he deleted all of the contents of the wrong server by mistake. To avoid that mistake again, he uses color codes in the command line in a fairly unique way.

The solution at first seems straightforward enough. Since the terminal he’s using allows for different colors to be displayed for the user and hostname on the bash prompt, different text and background colors are used for each server. The only problem with this is that his friends also have access to these servers, and one of them is red/green colorblind, which led to another near-catastrophic mix-up. To ensure no edge cases are missed, [Callan] built a script which runs on every new server he spins up which selects two random colors, checks that they contrast well with each other, don’t create problems for the colorblind, and then applies them to the bash prompt.

For a problem most of us have had at some point or another, it’s a fairly elegant solution that helps ensure we’re sending the right commands to the right computer. This adds a layer of automation to the process and, while some color combinations do look similar, there are enough to help out most of us in some way, especially since he has released the source code on his GitHub page. For other helpful server administration tips, we’d recommend the Linux-Fu article about deploying your own dynamic DNS.

The Cyber Resilience Act Threatens Open Source

April 21, 2023 by Al Williams 60 Comments

Society and governments are struggling to adapt to a world full of cybersecurity threats. Case in point: the EU CRA — Cyber Resilience Act — is a proposal by the European Commission to enact legislation with a noble goal: protect consumers from cybercrime by having security baked in during design. Even if you don’t live in the EU, today’s global market ensures that if the European Parliament adopts this legislation, it will affect the products you buy and, possibly, the products you create. In a recent podcast, our own [Jonathan Bennett] and [Doc Searles] interview [Mike Milinkovich] from the Eclipse Foundation about the proposal and what they fear would be almost a death blow to open source software development. You can watch the podcast below.

If you want some background, you can read the EU’s now closed request for comments and the blog post outlining the problems from opensource.org. At the heart of the issue is the need for organizations to self-certify their compliance with the act. Since open source is often maintained by a small loose-knit group of contributors, it is difficult to see how this will work.

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A black and white image of the Sun and Earth with a series of lines radiating out from the sun and bisecting rings circumscribed around it. On the Earth are three dots with the text "Active Server" on one exposed to the Sun and two dots representing "Inactive Server"s on the dark side.

Solar Protocol Envisions A Solar-Powered Web

April 21, 2023 by Navarre Bartz 34 Comments

The transition to low carbon energy is an important part of mitigating climate change, and the faster we can manage, the better. One project looking at how we could reduce the energy requirements of the web to more quickly adopt renewable energy is Solar Protocol.

Instead of routing requests to the fastest server when a user pulls up a website, Solar Protocol routes the request to the server currently generating the greatest amount of solar power. Once a user is on a website, the experience is energy-responsive. Website style and image resolution can range based on the power left in the active server’s batteries, including an image free low power mode.

Another benefit to the project’s energy efficiency approach is a focus on only the essential parts of a page and not any of the tracking or other privacy-endangering superfluous features present on many other websites. They go into much more depth in the Solar Protocol Manifesto. As a community project, Solar Protocol is still looking for more stewards since the network can go down if an insufficient number of servers are generating electricity.

For more details on the project that inspired Solar Protocol, check out this low-tech website.