Hard Disk Drives Have Made Precision Engineering Commonplace

Modern-day hard disk drives (HDDs) hold the interesting juxtaposition of being simultaneously the pinnacle of mass-produced, high-precision mechanical engineering, as well as the most scorned storage technology. Despite being called derogatory names such as ‘spinning rust’, most of these drives manage a lifetime of spinning ultra-smooth magnetic storage platters only nanometers removed from the recording and reading heads whose read arms are twitching around using actuators that manage to position the head precisely above the correct microscopic magnetic trace within milliseconds.

Despite decade after decade of more and more of these magnetic traces being crammed on a single square millimeter of these platters, and the simple read and write heads being replaced every few years by more and more complicated ones, hard drive reliability has gone up. The second quarter report from storage company Backblaze on their HDDs shows that the annual failure rate has gone significantly down compared to last year.

The question is whether this means that HDDs stand to become only more reliable over time, and how upcoming technologies like MAMR and HAMR may affect these metrics over the coming decades.

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Adding MIDI To A Mini Synth Is Easy As Pi

There are a handful of relatively dirt cheap synths out there like the KORG Monotron, but many of them use ribbon controllers that aren’t very precise.  Ribbon controllers basically slide pots that you operate with your finger or a stylus.  They’re painted to look like piano keys in order to show you approximately where the notes are supposed to be. The Stylophone is another extremely affordable synth that does even less as a synthesizer and uses this type of input. It’s a fun input if you don’t mind imprecision, but can be annoying otherwise.

[schollz] isn’t satisfied to synth this way, so they added MIDI input to their KORG Monotron using a Raspberry Pi and a DAC. Fortunately, the Monotron is quite the hackable little synth, with nice, big, labelled pads on the PCB.

All it really took was a couple of solder joints in the right places, plus a clever Python script. The script listens for MIDI input from a keyboard, and then controls an MCP4725 DAC, which sends voltages to the Monotron. [schollz] wrote a tuning function that computes the FFT of the MIDI tones to find the fundamental frequencies of each to send along to the Monotron. Check it out after the break.

If liquid control is what you’re after but all you have is a keyboard, try making your own ribbon controller.

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The ZX Microdrive: Budget Data Storage, 1980s Style

An enduring memory for most who used the 8-bit home computers of the early 1980s is the use of cassette tapes for program storage. Only the extremely well-heeled could afford a disk drive, so if you didn’t fancy the idea of waiting an eternity for your code to load then you were out of luck. If you had a Sinclair Spectrum though, by 1983 you had another option in the form of the unique Sinclair ZX Microdrive.

This was a format developed in-house by Sinclair Research that was essentially a miniaturized version of the endless-loop tape carts which had appeared as 8-track Hi-Fi cartridges in the previous decade, and promised lightning fast load times of within a few seconds along with a relatively huge storage capacity of over 80 kB. Sinclair owners could take their place alongside the Big Boys of the home computer world, and they could do so without breaking the bank too much.

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Finalists Announced For The 2020 Hackaday Prize

In light of everything going on in 2020, the 7th annual Hackaday Prize is devoted to nurturing ideas that could literally help change the world. In a first, we partnered with several nonprofits to help identify some of today’s most difficult problems, ranging from conservation and disaster relief to the need for advanced assistive technology. With over $200,000 up for grabs, including microgrants to help teams work full-time on their projects, this year’s competition was designed to help bring critical solutions to fruition which otherwise might never see the light of day.

But it hasn’t been easy. The global pandemic has made it far more difficult to collaborate on projects in the way we’re all used to, parts have become harder to source, and many makers found themselves so engaged with grassroots efforts to combat COVID-19 that they found little time for anything else. But despite all of this uncertainty, we received hundreds of incredible entries from all over the globe.

It’s never easy to select who will move on to the next round of the competition. But with the help of our nonprofit partners, the panel of expert judges was able to whittle the list of entries down to the 34 finalists that produced some of the most impressive and impactful ideas the Hackaday Prize has ever seen. Let’s take a look at just a few of the projects that will be vying for the top prizes in November.

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Soldering Glass And Titanium With Ultrasonic Energy

Ultrasonic soldering is a little-known technology that allows soldering together a variety of metals and ceramics that would not normally be possible. It requires a special ultrasonic soldering iron and solder that is not cheap or easy to get hold of, so [Ben Krasnow] of [Applied Science] made his own.

Ultrasonic soldering irons heat up like standard irons, but also require an ultrasonic transducer to create bonds to certain surfaces. [Ben] built one by silver soldering a piece of stainless steel rod (as a heat break) between the element of a standard iron and a transducer from an ultrasonic cleaner. He made his special active solder by melting all the ingredients in his vacuum induction furnace. It is similar to lead-free solder, but also contains titanium and small amounts of cerium and gallium. In the video below [Ben] goes into the working details of the technology and does some practical experimentation with various materials.

Ultrasonic soldering is used mainly for electrically bonding metals where clamping is not possible or convenient. The results are also not as neat and clean as with standard solder. We covered another DIY ultrasonic soldering iron before, but it doesn’t look like that one ever did any soldering.

Ultrasonic energy has several interesting mechanical applications that we’ve covered in the past, including ultrasonic cutting and ultrasonic welding.

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Open Source VR Headset For $200

We’ve seen homemade VR headsets before, but, often they are dependent on special software or are not really up to par with commercial products. Not so with Relativity, an open source project from [Max Coutte] and [Gabriel Combe]. [Max] says it best:

Relativty is not a consumer product. We made Relativty in my bedroom with a soldering iron and a 3D printer and we expect you to do the same: build it yourself.

Unlike some homebrew gear, Relativity has full Steam VR support. It also has experimental support for positional scaling that tracks your body based on video input.

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Security This Week: Racoons In My TLS, Bypassing Frontends, And Obscurity

Raccoon is the next flashy security flaw with a name, cute logo, and a website (and a PDF). Raccoon is a flaw in TLS version prior to 1.3, and seems to be a clever bit of work, albeit one with limited real-world application. The central problem is that these older versions of TLS, when using Diffie Hellman (DH), drop leading all-zero bytes in the resulting pre-master key. As that key is part of the input for calculating the master session key, a shortened pre-master key results in a slightly faster calculation of the master key. If an attacker can make fine-grained timing measurements, he can determine when the pre-master key is trimmed.

Let’s review Diffie Hellman, briefly. The client and server agree on two numeric values, a base g and modulus p, and each party generates a secret key, a and b. Each party calculates a public key by raising the shared base to their own private key, mod the shared modulus: A = g^a mod p. These public keys are exchanged, and each party raises the received key to their own secret key: A^b. Exponents have a non-obvious quirk, the power rule. A value raised to a power raised to a power is the same as the value raised to the power of the exponents multiplied together. g^a^b is equal to g^(a*b). By going through this mathematical dance, the server and client have arrived at a shared value that only they know, while preserving the secrecy of their private keys. Continue reading “Security This Week: Racoons In My TLS, Bypassing Frontends, And Obscurity”