Tiny11 Makes Windows 11 Small

February 21, 2023 by Al Williams 81 Comments

If you often spin up a virtual machine just to run Windows, you might be sad that you have to allocate so much space for it. The Tiny11 project provides a Windows 11 installer that strips and compresses a bare minimum system do under 8GB of space. We aren’t sure what the licensing aspects of it all mean, but there are a few things you need to know. You can see a video about the project below.

The installer requires you to activate Windows, so that’s probably a good thing from a legal standpoint. Besides being compressed, the installer, based on Window 11 Pro 22H2, removes sponsored applications and Teams. It does, however, have the component installer and the Microsoft store, so you can add back things you want that aren’t in the default install.

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OpenStructures Is A Modular Building System For The RepRap Age

February 21, 2023 by Navarre Bartz 24 Comments

Modular construction toys like LEGO and Meccano are great for prototyping, but they aren’t so great for large builds. OpenStructures promises to be a modular building system for projects large and small.

Originally conceived in 2007 by [Thomas Lommée], OpenStructures is a modern, more robust reinterpretation of Grid Beam, which was itself a reinterpretation of the earlier Living Structures. By using a common standard (PDF), parts can be reused project after project as they would with LEGO, meaning you can spend more time building and less time cutting or figuring out joints. OpenStructures parts need connection points, part diameters, or part dimensions at multiples of 20 mm to be compatible. To fulfill the spirit of the project, parts should be designed for disassembly, use recyclable materials when possible, and be Open Source.

The system seems like a great starting point for prototyping furniture or other large builds more quickly than building everything on a case-by-case basis. By including diameters for round objects as well as square and rectangular profiles, OpenStructures is a more flexible (and aesthetically pleasing?) option than Grid Beam.

A couple more options for furniture-scale modular construction are these big LEGO bricks or copper pipe.

(via Low Tech Magazine)

Travel The World Looking For Retro Tech, Virtually

February 21, 2023 by Tom Nardi 1 Comment

For those who have a passion for vintage hardware, whether it be a classic computer or a war-surplus ham radio rig, finding the things without resorting to paying shipping fees on eBay can sometimes be tricky. Your best bet is to find a local fair or swap event, but it always seems they’re the kind of thing you find out about the weekend after they were held.

Looking to make these sort of events more visible and easier to keep track of, [RobSmithDev] has created the Retro.Directory. Scrolling your way across the globe you can see markers that indicate places of interest for the retro aficionado, such as museums, repair shops, and old school arcades, as well as upcoming events. Continue reading “Travel The World Looking For Retro Tech, Virtually” →

Retro Gadgets: Make Your Scope Dual Channel

February 21, 2023 by Al Williams 32 Comments

We live in a time when having an oscilloscope is only a minor luxury. But for many decades, a good scope was a major expense, and almost no hobbyist had a brand new one unless it was of very poor quality. Scopes were big and heavy and, at the price most people were willing to pay, only had a single channel. Granted, having one channel is better than having nothing. But if the relative benefit of having a single channel scope is 10 points, the benefit of having two channels is easily at least 100 points. So what was a poor hacker to do when a dual-trace or higher scope cost too much? Why, hack, of course. There were many designs that would convert a single trace scope into a poor-quality multichannel scope. Heathkit made several of these over the years like the ID-22, the ID-101, and the ID-4101. They called them “electronic switches.” The S-2 and S-3 were even earlier models, but the idea wasn’t unique to Heathkit and had been around for some time.

For $25, you could change your scope to dual trace!

There were two common approaches. With alternative or alt mode, you could trigger a sync pulse and draw one trace. Then trigger again and draw the second trace with a fixed voltage offset. If you do this fast enough, it looks like there are two traces on the screen at one time. The other way is to rapidly switch between voltages during the sweep and use the scope’s Z input to blank the trace when it is between signals. This requires a Z input, of course, and a fast switching clock. This is sometimes called “chopper mode” or, simply, chop. This wasn’t just the realm of adapters, though. Even “real” analog scopes that did dual channels used the same methods, although generally with the benefit of being integrated with the scope’s electronics.

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3D Printing Antennas With Dielectric Resin

February 21, 2023 by Al Williams 14 Comments

[Machining and Microwaves] has long wanted to use a 3D printer to print RF components for antennas and microwave lenses. He heard that Rogers — the company known for making PCB substrates, among other things — had a dielectric resin available and asked them if he could try some. They agreed, with some stipulations, including that he had to visit their facility and show his designs in a video. Because of that, the video seems a little bit like a commercial, but we think he is genuinely excited about the possibility of the resin.

Since he was in their facility, he was able to interview several of the people behind the resin, and they had some interesting observations about keeping resin consistent during printing and how the moonbounce feed he wanted to print would work.

Some of the exotic RF test equipment was interesting to see, too. The microwave lenses look like some kind of modern art. According to the Roger’s website:

Radix Printable Dielectric materials are a ceramic-filled, UV-curable polymer designed for use with photopolymer 3D-printing processes like sterolithography (SLA) and digital light processing (DLP) printing. These materials and printing processes enable the use of high-resolution, scalable 3D-printing for complex RF dielectric components such as gradient index (GRIN) lenses or three-dimensional circuits. The 2.8Dk printable dielectric is designed to have low loss characteristics through millimeter wave (mmWave) frequencies and low moisture absorption for end-use applications.

It isn’t clear to us that you could use this resin in your own printers, but they did look pretty similar to what we have hanging around except, perhaps, for the continuous circulation of the resin pool. We figured the resin wasn’t inexpensive. In fact, we found a liter online for $1,863. We don’t know if that’s the suggested retail price or not, but we also suppose if you need this material, you won’t be that surprised at the cost.

If you don’t need microwave frequencies, you might be able to get by with some easier techniques. Or, you can even do something slightly more difficult but probably a lot cheaper.

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SUPERCON 2022: Kuba Tyszko Cracks Encrypted Software

February 21, 2023 by Dave Rowntree 5 Comments

[Kuba Tyszko] like many of us, has been hacking things from a young age. An early attempt at hacking around with grandpa’s tractor might have been swiftly quashed by his father, but likely this was not the last such incident. With a more recent interest in cracking encrypted applications, [Kuba] gives us some insights into some of the tools at your disposal for reading out the encrypted secrets of applications that have something worth hiding. (Slides here, PDF.)

There may be all sorts of reasons for such applications to have an encrypted portion, and that’s not really the focus. One such application that [Kuba] describes was a pre-trained machine-learning model written in the R scripting language. If you’re not familiar with R, it is commonly used for ‘data science’ type tasks and has a big fan base. It’s worth checking out. Anyway, the application binary took two command line arguments, one was the encrypted blob of the model, and the second was the path to the test data set for model verification.

The first thing [Kuba] suggests is to disable network access, just in case the application wants to ‘dial home.’ We don’t want that. The application was intended for Linux, so the first port of call was to see what libraries it was linked against using the ldd command. This indicated that it was linked against OpenSSL, so that was a likely candidate for encryption support. Next up, running objdump gave some clues as to the various components of the binary. It was determined that it was doing something with 256-bit AES encryption. Now after applying a little experience (or educated guesswork, if you prefer), the likely scenario is that the binary yanks the private key from somewhere within itself reads the encrypted blob file, and passes this over to libssl. Then the plaintext R script is passed off to the R runtime, the model executes against the test data, and results are collated.

[Kuba]’s first attack method was to grab the OpenSSL source code and drop in some strategic printf() function calls into the target functions. Next, using the LD_PRELOAD ‘trick’ the standard system OpenSSL library was substituted with the ‘fake’ version with the trojan printfs. The result of this was the decryption function gleefully sending the plaintext R script direct to the terminal. No need to even locate the private key!

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