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Longform articles, the best of what the Hackaday writing crew has to offer.

Tales From The Sysadmin: Impending Hard Drive Doom

July 14, 2020 by 70 Comments

It should have been another fine day, but not all was well in paradise. Few things bring a creeping feeling of doom like a computer that hardlocks and then refuses to boot. The clicking sound coming from the tower probably isn’t a good sign either. Those backups are up to date, right? Right?

There are some legends and old stories about hard drive repair. One of my favorites is the official solution to stiction for old drives: Smack it with a mallet. Another trick I’ve heard repeatedly is to freeze a hard drive before trying to read data off of it. This could actually be useful in a couple instances. The temperature change can help with stiction, and freezing the drive could potentially help an overheating drive last a bit longer. The downside is the potential for condensation inside the drive. Don’t turn to one of these questionable fixes unless you’ve exhausted the safer options.

For the purpose of this article, we’ll assume the problem is the hard drive, and not another component like a power supply or SATA cable causing problems. A truly dead drive is a topic for another time, but if the drive is alive enough to show up as a block device when plugged in, then there’s hope for recovering the data. One of the USB to SATA cables available on your favorite online store is a great way to recover data. Another option is booting off a Linux DVD or flash drive, and accessing the drive in place. If you’re lucky, you can just copy your files and call it a day. If the file transfer fails because of the dying drive, or you need a full disk image, it’s time to pull out some tools and get to work. Continue reading “Tales From The Sysadmin: Impending Hard Drive Doom” →

Changing System Architectures And The Complexities Of Apple’s Butterfly Approach To ISAs

July 13, 2020 by 64 Comments

Apple computers will be moving away from Intel chips to its own ARM-based design. An interesting thing about Apple as a company is that it has never felt the need to tie itself to a particular system architecture or ISA. Whereas a company like Microsoft mostly tied its fortunes to Intel’s x86 architecture, and IBM, Sun, HP and other giants preferred vertical integration, Apple is currently moving towards its fifth system architecture for its computers since the company was formed.

What makes this latest change possibly unique, however, is that instead of Apple relying on an external supplier for CPUs and peripheral ICs, they are now targeting a vertical integration approach. Although the ARM ISA is licensed to Apple by Arm Holdings, the ‘Apple Silicon’ design that is used in Apple’s ARM processors is their own, produced by Apple’s own engineers and produced by foundries at the behest of Apple.

In this article I would like to take a look back at Apple’s architectural decisions over the decades and how they made Apple’s move towards vertical integration practically a certainty.

Continue reading “Changing System Architectures And The Complexities Of Apple’s Butterfly Approach To ISAs” →

How Early Radio Receivers Worked

July 10, 2020 by 43 Comments

If you’ve ever built a crystal radio, there’s something magical about being able to pull voices and music from far away out of thin air. If you haven’t built one, maybe you should while there’s still something on the AM band. Of course, nowadays the equivalent might be an SDR. But barring a computer solution, there are not many ways to convert radio waves into intelligence. From a pocket radio to advanced RADAR to a satellite in orbit, receiving a radio wave is accomplished in pretty much the same way.

There are, however, many ways to modulate and demodulate that radio wave. Of course, an AM radio works differently than an FM radio. A satellite data downlink works differently, too. But the process of capturing the radio wave from the air and getting them into a form ready for further processing hasn’t changed much over the years.

In this article, I’ll talk about the most common radio receiver architectures you may have seen in years past, and next week I’ll talk about modern architectures. Either way, understanding receiver architectures will help you design new radios or troubleshoot them.

Continue reading “How Early Radio Receivers Worked” →

The Simplest TS100 Upgrade Leads Down A Cable Testing Rabbit Hole

July 9, 2020 by 54 Comments

By now, I must have had my Miniware TS100 soldering iron for nearly three years. It redefined what could be expected from the decent end of the budget soldering iron spectrum when it came on the market, and it’s still the one to beat even after those years. Small, lightweight, powerful, and hackable, it has even spawned direct imitations.

If the TS100 has a fault, it comes not from the iron itself but from its cable. A high-grade iron will have an extra-flexible PVC or silicone cable, but the TS100 does not have a cable of its own. Instead it relies on whatever cable comes on its power supply, which is frequently a laptop unit built with portable computing rather than soldering in mind. So to use it is to be constantly battling against its noticable lack of flexibility, a minor worry but one that I find irksome. I determined to find a solution, making a DC extension cable more flexible than that on my power supply. Continue reading “The Simplest TS100 Upgrade Leads Down A Cable Testing Rabbit Hole” →

Bridge Over Trebled Water: How The Golden Gate Bridge Started To Sing

July 8, 2020 by 28 Comments

Throughout the spring, some Bay Area residents from Marin County to the Presidio noticed a sustained, unplaceable high-pitched tone. In early June, the sound reached a new peak volume, and recordings of the eerie noise spread across Twitter and Facebook. Soon after, The Golden Gate Bridge, Highway, & Transportation District, the agency responsible for the iconic suspension bridge’s maintenance, solved the mystery: The sound was due to high winds blowing through the slats of the bridge’s newly-installed sidewalk railing. Though a more specific explanation was not provided, the sound is most likely an Aeolian tone, a noise produced when wind blows over a sharp edge, resulting in tiny harmonic vortices in the air.

The modification of the Golden Gate Bridge railing is the most recent and most audible element of a multi-phase retrofit that has been underway since 1997. Following the magnitude 6.9 Loma Prieta Earthquake in 1989, The Golden Gate Bridge, Highway, & Transportation District (The District) began to prepare the iconic bridge for the wind and earthquake loads that it may encounter in its hopefully long life. Though the bridge had already withstood the beating of the Bay’s strong easterly winds and had been rattled by minor earthquakes, new analysis technology and construction methods could help the span hold strong against any future lateral loading. The first and second phases of the retrofit targeted the Marin Viaduct (the bridge’s north approach) and the Fort Point Arch respectively. The third and current phase addresses the main span.

Continue reading “Bridge Over Trebled Water: How The Golden Gate Bridge Started To Sing” →

Not Just GPS: New Options For Global Positioning

July 7, 2020 by 79 Comments

A few weeks ago, China launched the final satellite in its BeiDou-3 satellite positioning system. Didn’t know that China had its own GPS? How about Europe’s Galileo, Russia’s GLONASS, or Japan’s QZSS? There’s a whole world of GPS-alikes out there. Let’s take a look.

Continue reading “Not Just GPS: New Options For Global Positioning” →

The WIMP Is Dead, Long Live The Solar Axion!

July 6, 2020 by 23 Comments

For decades scientists have been building detectors deep underground to search for dark matter. Now one of these experiments, the XENON1T detector, has found an unexpected signal in their data. Although the signal does not stem from dark matter it may still revolutionize physics.

Since the 1980s the majority of scientists believe that the most likely explanation for the missing mass problem is some yet undiscovered Weakly Interacting Massive Particle (WIMP). They also figured that if you build a large and sensitive enough detector we should be able to catch these particles which are constantly streaming through Earth. So since the early 1990s, we have been putting detectors made from ultrapure materials in tunnels and mines where they are shielded from cosmic radiation and natural radioactivity.

Over the decades these detectors have increased their sensitivity by a factor of about 10 million due to ever more sophisticated techniques of shielding and discriminating against before mentioned backgrounds. So far they haven’t found dark matter, but that doesn’t mean the high-end sensing installations will go unused.

Continue reading “The WIMP Is Dead, Long Live The Solar Axion!” →