How Does Time Work On The Moon?

March 26, 2024 by Lewin Day 46 Comments

We’re looking to go back to the Moon. Not just with robots this time, but with astronauts, too! They’ll be doing all kinds of interesting things when they get there. Maybe they’ll even work towards establishing a more permanent presence for humanity on the lunar surface, in which case they’ll have to get up in the morning, eat breakfast, and get to work.

This raises the question—how does time work on the Moon? As simple as they can be down here, Earthly days and years have little meaning up there, after all. So what’s going on up there?

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Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Pickle Pi

March 25, 2024 by Kristina Panos 1 Comment

The unstoppable [jefmer] wrote in to alert me to Pickle Pi, their latest Keebin’-friendly creation. Why “Pickle Pi”? Well, the Pi part should be obvious, but the rest comes from the Gherkin 30% ortholinear keyboard [jefmer] built with Gateron Yellows and, unfortunately, second-choice XDA keycaps, as the first batch were stolen off of the porch.

If you’re wondering where the rest of the keys are, they are accessible by holding various keys rather than tapping them. Shift is Shift when ~~tapped~~ held, but becomes Enter when tapped. [jefmer] wrote out their entire project description on the thing in order to break in the Gherkin.

The brains of this acrylic sandwich tablet is a Pi Zero 2, with a Pro Micro for the keyboard controller. Although programs like Ghostwriter and Thonny work fine, Chromium is “painfully slow” due to the RAM limitations of the Pi Zero 2. On the upside, battery life is 7-8 hours depending on usage. Even so, [jefmer] might replace it with a Pi 4 — the current battery pack won’t support a Pi 5.
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User Beware: The Fine Line Between Content And Code

March 25, 2024 by Tom Nardi 29 Comments

Everyone loves themes. Doesn’t matter if it’s a text editor or a smart display in the kitchen, we want to be able to easily customize its look and feel to our liking. When setting up a new device or piece of software, playing around with the available themes may be one of the first things you do without giving it much thought. After all, it’s not like picking the wrong one is going to do something crazy like silently delete all the files on your computer, right?

Unfortunately, that’s exactly what happened a few days ago to [JeansenVaars] while trying out a Plasma Global Theme from the KDE Store. According to their Reddit post, shortly after installing the “Gray Layout” theme for the popular Linux graphical environment, the system started behaving oddly and then prompted for a root password. Realizing something didn’t seem right they declined, but at that point, it was already too late for all of the personal files in their home directory.

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Hackaday Links: March 24, 2024

March 24, 2024 by Dan Maloney 6 Comments

Way to rub it in, guys. As it turns out, due to family and work obligations we won’t be able to see the next Great American Eclipse, at least not from anywhere near the path of totality, when it sweeps from Mexico into Canada on April 8. And that’s too bad, because compared to the eclipse back in 2017, “Eclipse 2: Solar Boogaloo” is occurring during a much more active phase in the solar cycle, with the potential for some pretty exciting viewing. The sun regularly belches out gigatons of plasma during coronal mass ejections (CMEs), most of which we can’t see with the naked eye because not only is staring at the sun not a great idea, but most of that activity occurs across the disk of the sun, obscuring the view in the background light. But during the eclipse, we — oops, you — might just get lucky enough to have a solar prominence erupt along the limb of the sun that will be visible during totality. The sun has been quite active lately, as reflected by the relatively high sunspot number, so even though it’s an outside chance, it’s certainly more likely than it was in 2017. Good luck out there. Continue reading “Hackaday Links: March 24, 2024” →

Why X86 Needs To Die

March 21, 2024 by Julian Scheffers 209 Comments

As I’m sure many of you know, x86 architecture has been around for quite some time. It has its roots in Intel’s early 8086 processor, the first in the family. Indeed, even the original 8086 inherits a small amount of architectural structure from Intel’s 8-bit predecessors, dating all the way back to the 8008. But the 8086 evolved into the 186, 286, 386, 486, and then they got names: Pentium would have been the 586.

Along the way, new instructions were added, but the core of the x86 instruction set was retained. And a lot of effort was spent making the same instructions faster and faster. This has become so extreme that, even though the 8086 and modern Xeon processors can both run a common subset of code, the two CPUs architecturally look about as far apart as they possibly could.

So here we are today, with even the highest-end x86 CPUs still supporting the archaic 8086 real mode, where the CPU can address memory directly, without any redirection. Having this level of backwards compatibility can cause problems, especially with respect to multitasking and memory protection, but it was a feature of previous chips, so it’s a feature of current x86 designs. And there’s more!

I think it’s time to put a lot of the legacy of the 8086 to rest, and let the modern processors run free. Continue reading “Why X86 Needs To Die” →

The F Number On A Lens Means Something? Who Knew!

March 18, 2024 by Jenny List 59 Comments

The Raspberry Pi has provided experimenters with many channels of enquiry, and for me perhaps the furthest into uncharted waters it has led me has come through its camera interface. At a superficial level I can plug in one of the ready-made modules with a built-in tiny lens, but as I experiment with the naked sensors of the HD module and a deconstructed Chinese miniature sensor it’s taken me further into camera design than I’d expected.

I’m using them with extra lenses to make full-frame captures of vintage film cameras, in the first instance 8 mm movie cameras but as I experiment more, even 35 mm still cameras. As I’m now channeling the light-gathering ability of a relatively huge area of 1970s glass into a tiny sensor designed for a miniature lens, I’m discovering that maybe too much light is not a good thing. At this point instead of winging it I found it was maybe a good idea to learn a bit about lenses, and that’s how I started to understand what those F-numbers mean.

More Than The Ring You Twiddle To Get The Exposure Right

lose-up of the end of a lens, showing the F-number range — The F-number range of a 1990s Sigma consumer-grade zoom lens.

I’m not a photographer, instead I’m an engineer who likes tinkering with cameras and who takes photographs as part of her work but using the camera as a tool. Thus the f-stop ring has always been for me simply the thing you twiddle when you want to bring the exposure into range, and which has an effect on depth of field.

The numbers were always just numbers, until suddenly I had to understand them for my projects to work. So the first number I had to learn about was the F-number of the lens itself. It’s usually printed on the front next to the focal length and expressed as a ratio of the diameter of the light entrance to the lens focal length. Looking around my bench I see numbers ranging from 1:1 for a Canon 8mm camera to 1:2.8 for a 1950s Braun Paxette 35 mm camera, but it seems that around 1:1.2 is where most 8 mm cameras sit and 1:2 is around where I’m seeing 35 mm kit lenses. The F-stop ring controls an adjustable aperture, and the numbers correspond to that ratio. So that 1:2 kit lens is only 1:2 at the F2 setting, and becomes 1:16 at the F16 setting.

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Keebin’ With Kristina: The One With The Offset-Stem Keycaps

March 18, 2024 by Kristina Panos 3 Comments

Love it or hate it, I think this is a really cool idea. [Leo_keeb] has designed a new set of keycaps for the Happy Hacking Keyboard (HHKB). The keycaps’ stems are offset to the left or right in order to turn this once-staggered keyboard into an ortholinear object.

So, how do they feel? There is a slight wobble to them, according to [Leo_keeb] — it’s a bit like pressing the left or right side of Tab. But the actuation is smooth, they say.

As you can see, these resin keycaps weren’t designed with the typical Cherry MX profile in mind, they are made for the Topre capacitive key switches of the HHKB. (No, those aren’t weird rubber domes.)

When I asked about sharing the STLs, [Leo_keeb] advised me that they might be willing to release STLs for Cherry MX switches in the US layout if there is enough interest.

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