Flashed The Wrong Firmware? Swap Out The LCD To Match!

October 27, 2015 by Elliot Williams 26 Comments

We always joke about the hardware guys saying that they’ll fix it in firmware, and vice-versa, but this is ridiculous. When [Igor] tried to update his oscilloscope and flashed the wrong firmware version in by mistake, he didn’t fix it in firmware. Instead, he upgraded the LCD display to match the firmware.

See, Siglent doesn’t make [Igor]’s DSO any more; they stopped using the 4:3 aspect ratio screens and replaced them with wider versions. Of course, this is an improvement for anyone buying a new scope, but not if you’ve got the small screen in yours and can’t see anything anymore. After playing around with flashing other company’s firmware (for a similar scope) and failing to get it done over the JTAG, he gave up on the firmware and started looking for a hardware solution.

It turns out that a few SMT resistors set the output screen resolution. After desoldering the appropriate resistors, [Igor] bought a new 7″ LCD screen online only to find out that it has a high-voltage backlight and that he’d need to build an inverter (and hide the noisy circuit inside his oscilloscope). Not daunted, he went digging through his junk box until he found a backlight panel of the right size from another display.

Yet more small soldering, and he had frankensteined a new backlight into place. Of course, the larger LCD won’t fit the case without some cutting, double-sided tape, and a healthy dose of black tape all around insulates the loose electricals. Et voilá!

We have to hand it to [Igor], he’s got moxie. It’s an ugly hack, but it’s a definite screen upgrade, and a lesser hacker would have stopped after flashing the wrong firmware and thrown the thing in the trash. We’d be proud to have that scope sitting on our desk; it’s a definite conversation starter, and a badge of courage to boot.

AROS: Run An Amiga OS Like It’s 1993

October 27, 2015 by Elliot Williams 7 Comments

We read this article on oddball open-source operating systems by [Bryan Lunduke] of the “Linux Action Show” podcast, and it caused us to play around in an Amiga-like operating system (running as a VM) for an hour. We’re pretty sure that you’ll succumb to the same fate. But even worse, the article is just the first in a series. There goes your weekend hacking productivity for the foreseeable future.

AROS is an open-source, API-compatible rewrite of the Amiga OS. Now, AROS is no fancy-schmancy AmigaOS4. No sir, the AROS project started in 1995 and settled on Amiga OS API version 3.1, and it stays true to its roots.

But this doesn’t mean that you’re going to have to give up the creature comforts of life in the 21st century. Get yourself a full-fledged AROS distribution, like icaros desktop, and you’ll find a pretty beefy ecosystem of applications included. It’s mostly what you’d want out of an Amiga — games, audio, video, and graphics editing software, a WebKit-based browser, and even a super-minimal word processor.

It’s retro, it’s sexy, and it’s fun. Just the ticket for running on that unused craptop gathering dust in the corner. (It’s also reported to run on Raspberry Pi running Linux.) Still not convinced? Lemmings.

TEMPEST: A Tin Foil Hat For Your Electronics And Their Secrets

October 19, 2015 by Elliot Williams 38 Comments

Electronics leak waves and if you know what you’re doing you can steal people’s data using this phenomenon. How thick is your tinfoil hat? And you sure it’s thick enough? Well, it turns out that there’s a (secret) government standard for all of this: TEMPEST. Yes, all-caps. No, it’s not an acronym. It’s a secret codename, and codenames are more fun WHEN SHOUTED OUT LOUD!

The TEMPEST idea in a nutshell is that electronic devices leak electromagnetic waves when they do things like switch bits from ones to zeros or move electron beams around to make images on CRT screens. If an adversary can remotely listen in to these unintentional broadcasts, they can potentially figure out what’s going on inside your computer. Read on and find out about the history of TEMPEST, modern research, and finally how you can try it out yourself at home!

Continue reading “TEMPEST: A Tin Foil Hat For Your Electronics And Their Secrets” →

Passive, But Not Innocuous

October 12, 2015 by Elliot Williams 19 Comments

Maxim Integrated recently posted a series of application notes chronicling how there’s more going on than you’d think in even the simplest “passive” components. Nothing’s safe: capacitors, resistors, and even printed circuit boards can all behave in non-ideal ways, and that can bite you in the reflow-oven if you’re not aware of them.

You might already know that capacitors have an equivalent series resistance that limits how fast they can discharge, and an equivalent inductance that models departures from ideal behavior at higher frequencies. But did you know that ceramic capacitors can also act like voltage sources, acting piezoelectrically under physical stress?

For resistors, you’ll also have to reckon with temperature dependence as well as the same range of piezoelectric and inductance characteristics that capacitors display. Worse, resistors can display variable resistance under higher voltages, and actually produce a small amount of random noise: Johnson Noise that depends on the value of the resistance.

Finally, the third article in the series tackles the PCB, summarizing a lot of potential manufacturing defects to look out for, as well as covering the parasitic capacitance, leakage currents, and frequency dependence that the actual fiberglass layers themselves can introduce into your circuit.

If you’re having a feeling of déjà-vu, the same series of articles ran in 2013 in Electronic Design but they’re good enough that we hope you won’t mind the redundant repetition all over again. And if you’re already quibbling with exactly what they mean by “passive”, we feel your pain: they’re really talking about parasitic effects, but we’ll let that slide too. We’re in a giving mood today.

[via Dangerous Prototypes]

Anvil Firing: Awesome Or Reckless?

October 11, 2015 by Elliot Williams 67 Comments

The English language needs a word for “awesome and dangerous simultaneously”.

We recently ran into the strange pastime of anvil shooting on YouTube (where else?). The idea is that you pack about a pound (!) of black powder between two anvils and light it up. The powder explodes, and the top anvil gets shot into the air. Hilarity ensues, if everyone’s far enough away and wearing hearing protection.

Continue reading “Anvil Firing: Awesome Or Reckless?” →

SDR Tutorials From Michael Ossmann

October 10, 2015 by Elliot Williams 7 Comments

If you’re just getting into software-defined radio (SDR) but you find some of the math and/or terminology a bit of hurdle, you could absolutely do worse than to check out these SDR tutorials by [Michael Ossmann]. While they’re aimed at people using his HackRF One tool (which we love), most of the tutorial videos are very generally applicable, and we realized that we hadn’t mentioned them explicitly before. Shame on us!

Ossmann focuses on SDR using the open-source GNURadio Companion GUI tool, which makes implementing a lot of cool SDR techniques as easy as dragging and dropping items into a flow diagram. If you want an overview of GNURadio or SDR in general, these videos are a must-watch.

In particular, we loved his entries on complex numbers and complex numbers in DSP because he goes through the whole rationale behind using imaginary numbers in radio work with a graphical presentation that helps add rationale to the otherwise slightly spooky math. Heck, watch these two even if you’re not interested in radio.

The newest entry, covering DSP filters includes a great hands-on introduction to finite impulse response (moving average) digital filters. We really like the practical, simulation-based approach presented in the video — it’s just perfect for a quick introduction.

So if you’re looking for a relatively painless way to get into SDR, grab yourself an RTL-SDR dongle, burn yourself a GNURadio Live DVD, and work through these videos.

Vintage Computer Fest: Berlin 2015

October 9, 2015 by Elliot Williams 19 Comments

Berlin was a good city to be a geek in last weekend. Alongside the Berlin Maker Faire, there was the 2015 meeting of the Vintage Computing Festival: Berlin (VCFB). Each VCFB has a special theme, and this year it was analogue computers, but there was no lack of old computers large and small, teletext machines, vintage video game consoles, and general nerdy nostalgia.