We’ve talked before about number stations — mysterious shortwave transmitters repeating numbers, presumably for clandestine purposes. But, of course, the mere fact that they are unusual makes them stand out. The best place to hide something is in plain sight. In the old days, a broadcaster might slip a fake news story in mentioning a name that has a secret meaning, for example. But according to [Steven Murdoch], the United States has an even more obvious hiding place for a numbers station: inside GPS.
Every L1 C/A navigation message is a 176-bit field known by the affectionate moniker: Subframe 4, Page 17. The GPS specification says it is for “special messages.” No one has disclosed what those messages might be.
[Murdoch] at University College London analyzed over 12 million GPS packets from 2007 to 2026, trying to understand what was in this field. You might think 176 bits isn’t much, and you are right. But the L1 C/A signal carries 50 bits per second, and each frame is 1,500 bits. As [Murdoch] points out: “every bit must earn its place.” Each subframe is 300 bits, so this mysterious signal is 12% of the subframe. It must be important to someone.
There are a lot of traditional features of a bike that rarely change. The spokes, the chain, and the inability for it to take off like a rocket, to mention a few. None of these are features of the Reevo, a bike that tried, and mostly failed, to innovate the traditional electric bike. [Berm Peak], an individual with more time on two wheels than the entire Reevo team ever had, tried his hand at fixing the Reevo’s many problems.
[Berm Peak] has had a go at the Reevo before, but this time he had to go a lot deeper. Before any real work could be done on the Reevo, the controller needed to be jailbroken since the only way to use most features required an app that wasn’t available. Surprisingly, the controller boards were found to be well labeled, and with some trial and error, the protocols could be reverse-engineered.
While it might seem that your computer malfunctions every few minutes, the reality is that modern computers are usually quite robust. Not so much for quantum computers, where qubit life is often measured in milliseconds. Now, the company claims to have qubits that last for about 20 seconds.
For example, Microsoft’s Majorana 1 quantum chip, which, incidentally, was mired in controversy, provided 8 qubits that were stable very briefly. This second-generation chip provides 12 qubits that average 20-second lifespans.
First introduced in 1979 by Signetics, the NE5532 was a pretty spiffy dual op-amp for the time with low noise and low distortion. Over the years it has become a standard part that showed up in countless audio products, and has become a so-called jellybean generic component with Texas Instruments (TI) being one of countless manufacturers.
It being such a standard, multi-sourced part makes it thus even more puzzling that TI has now decided to completely overhaul this IC in a way that makes it incompatible with even the original Signetics NE5532. These changes are covered in detail by [Dave] of EEVblog as his mind is pretty much blown at such an incomprehensible change.
The changes entail an entirely different manufacturing process and a big change in specifications, while making no change to the part number. In revision K of the TI datasheet these changes are first seen, with some specifications changed for the better, like a higher unity gain bandwidth by 2 MHz, but a much slower slew rate.
Texas Instruments SA5532A variant of the 5532 op-amp. (Credit: Raimond Spekking, Wikimedia)
Although the 5532 op-amps are multi-sourced, there are good reasons to just stick with manufacturers like TI, as that means receiving a product change notification (PCN) when anything changes. In the PCN related to this op-amp a change to process node is noted, along with other changes, but no reasoning.
Among the other big changes are a reduction in the supply voltage from 22 V to 18 V, and a halving of the ESD protection from 2 kV to 1 kV. Although it might be slightly more efficient on the new process node this way, it clearly comes with a lot of trade-offs that make it an overall worse op-amp, while also being incompatible with the same op-amp from other manufacturers.
In the video [Dave] goes through the datasheets of this jellybean part of other manufacturers, showing that they still have the original 1980s specifications. Only one exception here was the NE5532DR from Shenzhen HuaXuanYang Electronics, whose supply rail voltage is also 18 V for some reason, along with a similar internal transistor configuration that reduces the ESD resistance.
In addition to the NE5532 op-amp, it seems that TI also took an axe to the OPA134 op-amp, by removing its offset trim feature and listing the pins as ‘NC’, with a warning to not connect these pins and also worsening other specifications. This makes these similar jellybean parts incompatible, with no change to the part number. Worse is that it continues with the LMH6518, whose changes [Dave] argues might even kill oscilloscopes as they are commonly found in those.
Meanwhile the LM317M also got an overhaul, but here TI opted to give it a new part name, calling it the LM317MQ with at first glance no major degradations in the specifications, but instead some actual improvements. This makes it even more puzzling why TI didn’t give the other ICs a new part number to differentiate them from the jellybean part.
Until there’s some clarification from the side of TI, it might be a good idea to source these parts from a manufacturer that is not TI, especially when replacing these ICs in older devices.
Some of you may know there’s a version of UNIX for the Commodore Amiga, aptly called Amiga Unix or AMIX. There is an almost complete record of versions from 1.0 to 2.03, but 2.02 was lost media–until [Forgotten Computer] found it on an old Amiga.
It starts with an auction held for the 40 year anniversary of the Free Software Foundation where, by just one second, the highest bidder was too late. What do you do first with an artifact as valuable as an old FSF computer? You image the hard drive. Then you make several copies, including on different computers–after all, you wouldn’t want to lose the data on it. Preservation secured, the natural next thing is to boot it–and that’s when we see the magic 2.02c version number.
According to thorough digging by [Forgotten Computer], this version was–until now–lost.
In the video after the break, [Forgotten Computer] goes over what Amiga Unix is, the discovery process, and explores what’s on the disk–including FSF staples like GCC, G++ and core utilities like GNU less. Continue reading “Lost Version Of Amiga Unix Suddenly Reappears”→
Storage is expensive these days, whether you’re looking at the prices of spinning rust or magic little sticks of silicon. But what if there was some benevolent overlord that you could trick into giving you unlimited storage? That’s where Noisecloud comes in.
Created by [Lucas], Noisecloud is a tool that lets you use YouTube as a form of effectively-unlimited file storage. It works by taking whatever file data you have on hand, and turns it into frames of digital noise that can be stored and transported as an MP4 file and uploaded to YouTube. The encoding process involves first compressing the data with gzip, then packaging it into a high-constrast series of video frames that are then encoded with FFmpeg. Video containers can be produced in various resolutions, all the way down to 640×360 @ 30 fps. There’s also a special “TikTok mode” which is optimised to best preserve data on short form sites that use vertical orientation as default. More commentary from the creator is available via the supporting article on Github.
It’s probably not a practical way to store your files, given the fussy encoding and decoding required to actually use the data. However, it’s an interesting proof of concept that explores how data can be stashed in unexpected places via publicly-accessible services. We’ve explored similar work before, too.
Solar power has gotten cheap enough that putting up panels is among the cheapest ways of providing energy. This isn’t just the case for bulk electricity on a power grid, either; even small devices are easier and cheaper to power with solar than ever before. For example, landscape lighting which once relied on 12V or 24V DC wires all over one’s yard with a transformer and power supply hidden somewhere have partially been converted to simpler individual solar-powered lights now. These small devices can also be given additional capabilities as [Mauro] demonstrates.
In this case, [Mauro]’s goal was to add on-demand lighting to a solar-powered light which was otherwise motion-activated only. To do this, they added a NRF24L01+ radio inside the light’s housing paired with an STM32 microcontroller. This secondary system is largely separated from the existing control circuitry with the exception of being able to switch the lights and receiving its power from the same solar panel. [Mauro] also created a small library to help with communicating with these new modules, whether that’s using a home automation system like Home Assistant or some other method.
Although adding in a few capabilities to inexpensive solar lighting might seem simple on the surface, a project like this is a gateway to adding in all kinds of interesting features to things with built-in solar panels and lots of free space in their cases. The best example here is the addition of a Meshtastic node to one of these lights, making it convenient and stealthy, but we could also see adding in other remote hardware to a landscape lighting module like a gate sensor or a plant health monitoring system.
