The Piezoelectric Glitching Attack

Many readers will be familiar with the idea of a glitching attack, introducing electrical noise into a computer circuit in the hope of disrupting program flow and causing unexpected behaviour which might lead to hitherto unavailable access to memory or other system resources. [David Buchanan] has written a piece investigating glitching attacks on PC memory, and the tool he’s used is the ubiquitous piezoelectric lighter.

Attaching a short piece of wire to one of the lines on a SODIMM memory module, he can glitch a laptop at will with the lighter through the electromagnetic noise its discharge creates. It’s a cool trick, but the real meat of the write-up lies in his comprehensive description of how virtual memory works, and how a glitch can be used to break out of the “sandbox” of memory allocated to a particular process. He demonstrates it in a video which we’ve placed below the break, in which he gains root access and runs an arbitrary piece of code on a Linux laptop. It’s probable that not many of us have the inclination to do this for ourselves, but even so it’s fascinating to know how such an attack works.

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The Turing Machine Made Real, In LEGO

The British mathematician and pioneer of computing Alan Turing published a paper in 1936 which described a Universal Machine, a theoretical model of a computer processor that would later become known as a Turing Machine. Practical computers don’t quite follow the design of a Turing Machine, but if we are prepared to sacrifice its need for an infinitely long paper tape it’s quite possible to build one. This is what [The Bananaman] has done using LEGO as a medium, and if you’d like one for yourself you can even vote for it on the LEGO ideas website.

There’s a video for the project which we’ve placed below, and it goes into quite some detail on the various mechanisms required. Indeed for someone used to physical machinery it’s a better explanation through seeing the various parts than many paper explanations. Not for the first time we’re bowled over by what is possible through the use of the LEGO precision mouldings, this is a machine which would have been difficult and expensive to build in the 1930s by individually machining all its parts.

With just shy of six thousand supporters and a hefty 763 days left at time of writing, there’s plenty of time for it to garner support. But if you want one don’t delay, boost the project by voting for it early.

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Why Electric Trains Sound The Way They Do

If you’re a seasoned international rail traveler you will no doubt have become used to the various sounds of electric locomotives and multiple units as they start up. If you know anything about electronics you’ll probably have made the connection between the sounds and their associated motor control schemes, but unless you’re a railway engineer the chances are you’ll still be in the dark about just what’s going on. To throw light on the matter, [Z&F Railways] have a video explaining the various control schemes and the technologies behind them.

It’s made in Scotland, so the featured trains are largely British or in particular Scottish ones, but since the same systems can be found internationally it’s the sounds which matter rather than the trains themselves. Particularly interesting is the explanation of PWM versus pattern mode, the latter being a series of symmetrical pulses at different frequencies to create the same effect as PWM, but without relying on a single switching frequency as PWM does. This allows the controller to more efficiently match its drive to the AC frequency demanded by the motor at a particular speed, and is responsible for the “gear change” sound of many electric trains. We’re particularly taken by the sound of some German and Austrian locomotives (made by our corporate overlords Siemens, by coincidence) that step through the patterns in a musical scale.

Not for the first time we’re left wondering why electric vehicle manufacturers have considered fake internal combustion noises to make their cars sound sporty, when the sound of true electrical power is right there. The video is below the break.

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An Open Source Mirrorless Camera You’d Want To Use

Making a digital camera is a project that appears easy enough, but it’s one whose complexity increases depending on the level to which a designer is prepared to go. At the simplest a Raspberry Pi and camera module can be stuck in a 3D printed case, but in that case, the difficult work of getting the drivers and electronics sorted out has already been done for you.

At the other end of the scale there’s [Wenting Zhang]’s open source mirrorless digital camera project, in which the design and construction of a full-frame CCD digital camera has been taken back to first principles. To understand the scale of this task, this process employs large teams of engineers when a camera company does it, and while it’s taken a few years and the software isn’t perhaps as polished as your Sony or Canon, the fact it’s been done at all is extremely impressive.

Inside is a Kodak full-frame sensor behind the Sony E-mount lens, for which all the complex CCD timing and acquisition circuitry has been implemented. The brains of the show lie in a Xilinx Zynq ARM-and-FPGA in a stack of boards with a power board and the CCD board. The controls and battery are in a grip, and a large display is on the back of the unit.

We featured an earlier version of this project last year, and this version is a much better development with something like the ergonomics, control, and interface you would expect from a modern consumer camera. The screen update is still a little slow and there are doubtless many tweaks to come, but this really feels close to being a camera you’d want to try. There’s an assembly video which we’ve placed below the break, feast your eyes on it.

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HackFest Enschede: The Type Of Indoor Event We Wanted All Along

I’m sitting at a table writing this in the centre of a long and cavernous industrial building, the former print works of a local newspaper, I’m surrounded by hardware and software hackers working at their laptops, around me is a bustling crowd admiring a series of large projects on tables along the walls, and the ambient sound is one of the demoscene, chiptunes, 3D-printed guitars, and improbably hurdy-gurdy music. Laser light is playing on the walls, and even though it’s quite a journey from England to get here, I’m home. This is Hackfest Enschede, a two-day event in the Eastern Dutch city which by my estimation has managed the near-impossible feat of combining the flavour of both a hacker event and a maker faire all in one, causing the two distinct crowds to come together.

The Best Of Both Worlds, In One Place

To give an idea of what’s here it’s time for a virtual trip round the hall. I’ll start with the music, aside from the demosceners there’s Printstruments with a range of 3D-printedmusical instruments, and Nerdy Gurdy, as you may have guessed, that hacker hurdy-gurdy I mentioned. This is perhaps one of few places I could have seen a spontaneous jam session featuring a 3D-printed bass and a laser-cut hurdy-gurdy. Alongside them were the Eurorack synthesisers of Sound Force, providing analogue electronic sounds aplenty. Continue reading “HackFest Enschede: The Type Of Indoor Event We Wanted All Along”

The Raspberry Pi 500 Hints At Its Existence

It’s fairly insignificant in the scheme of things, and there’s no hardware as yet for us to look at, but there it is. Tucked away in a device tree file, the first mention of a Raspberry Pi 500. We take this to mean that the chances of an upgrade to the Pi 400 all-in-one giving it the heart of a Pi 5 are now quite high.

We’ve remarked before that one of the problems facing the Raspberry Pi folks is that a new revision of the regular Pi no longer carries the novelty it might once have done, and certainly in hardware terms (if not necessarily software) it could be said that the competition have very much caught up. It’s in the Compute Module and the wildcard products such as the all-in-one computers that they still shine then, because even after several years of the 400 it’s not really seen an effective competitor.

So we welcome the chance of an all-in-one with a Pi 5 heart, and if we had a wish list for it then it should include that mini PCI-E slot on board for SSDs and other peripherals. Such a machine would we think become a must-have for any space-constrained bench.

Retrotechtacular: Another Thing Your TV No Longer Needs

As Hackaday writers we don’t always know what our colleagues are working on until publication time, so we all look forward to seeing what other writers come up with. This week it was [Al Williams] with “Things Your TV No Longer Needs“, a range of gadgets from the analogue TV era, now consigned to the history books. On the bench here is a device that might have joined them, so in taking a look at it now it’s by way of an addendum to Al’s piece.

When VHF Was Not Enough

In a Dutch second-had store while on my hacker camp travels this summer, I noticed a small grey box. It was mine for the princely sum of five euros, because while I’d never seen one before I was able to guess exactly what it was. The “Super 2” weighing down my backpack was a UHF converter, a set-top box from before set-top boxes, and dating from the moment around five or six decades ago when that country expanded its TV broadcast network to include the UHF bands. If your TV was VHF it couldn’t receive the new channels, and this box was the answer to connecting your UHF antenna to that old TV.

It’s a relatively small plastic case about the size of a chunky paperback book, on the front of which is a tuning knob and scale in channels and MHz, on the top of which are a couple of buttons for VHF and UHF, and on the back are a set of balanced connectors for antennas and TV set. It’s mains powered, so there’s a mains lead with an older version of the ubiquitous European mains plug. Surprisingly it comes open with a couple of large coin screws on the underside, so it’s time to take a look inside. Continue reading “Retrotechtacular: Another Thing Your TV No Longer Needs”