A Low Voltage Tube Makes For A Handy Preamplifier

November 17, 2023 by Jenny List 29 Comments

When most people think of tube circuits, the first thing that comes to mind is often the use of high-voltage power supplies. It wasn’t a given for tube circuits, though, as a range of low-voltage devices were developed for applications such as car radios. It’s one of these, an ECH83 triode-heptode, which [mircemk] has taken as the basis of an audio preamplifier circuit.

The preamp circuit is pretty simple, being a two-stage single-ended design using both halves of the tube. Between the two is a three-band tone control circuit as used in classic guitar amplifiers, making for a serviceable and easily achievable way to chase that elusive “valve sound.”

There is much discussion among audio enthusiasts about the supposed benefits of vacuum technology as opposed to transistors in an amplifier. Much of it centres around the idea that tubes distort in the even harmonics while semiconductors are supposed to do so in the odd harmonics. Still, we’d be inclined to spot a bit of snake oil instead and point to early transistor amplifiers simply being not very good compared to the tube amps of the day. That said, a well-made tube amplifier set-up will sound just as amazing as it always did, and since this one is paired with a matching power amp we wouldn’t say no to it ourselves.

If you fancy messing about with tubes for not a lot, there’s a cheap module for that.

The masks with which the Intel 4004 was fabricated

Supersize Your Intel 4004 By Over 10 Times

November 17, 2023 by Julian Scheffers 22 Comments

A PCB covered in discrete transistors with light shining through it — This is quite a bit bigger than the original 12mm² die.

The Intel 4004 was among the first microprocessors and one of the first to use the MOS silicon-gate technology. In the decades long race to build bigger CPUs, it’s been mostly forgotten. Forgotten that is, until [Klaus Scheffler] supersized it over ten-fold!

The project took about 2 years to complete and re-creates it faithfully – all 2,300 transistors included – enough to run software written for the Intel 4004. But the idea for this project isn’t unique and dates all the way back to 2000, so what gives? Turning a bunch of masks for silicon fabrication into a schematic is actually harder than it seems! [Tim McNerney] originally came up with the idea to make a giant 4004 for its “35th anniversary”. [Tim] managed to convince Intel to give him schematics and other drawings and would in return make an exhibit for Intel’s museum. With the schematic straight from [Federico Faggin], software analysis tools from [Lajos Kintli] and [Klaus Scheffler] to actually build the thing, they did what [Federico] did in one year without CAD, but in two with modern tools.

The full story by [Tim] is a lot longer and it’s definitely worth a read.

You Can Now Build Your Own Polaroid-style Pack Film Cartridge

November 17, 2023 by Jenny List 5 Comments

Instant photography was one of the twentieth century’s coolest-to-have consumer inventions, but when the digital photography revolution came it had few answers. It survives as a niche format thanks to Fuji’s Instax line and a group of Dutch entrepreneurs who revived a defunct Polaroid works, but what hasn’t made it are the earlier pack and roll film formats for which the picture is revealed by peeling apart a negative and positive side. All isn’t lost though, because a small Austrian company has been producing pack film cartridges as a handmade artisan product. To reduce the cost per print they’re now available as a DIY self-assembly kit, and it’s this which [In an Instant] is taking a look at in their latest video.

The kit has enough components for eight shots, and where the original cartridge would have held multiple exposures this one can only hold one at a time. The cartridge itself is cleverly formed from folded card as opposed to the plastic and metal of the original, and the components are a relatively straightforward assembly task. It’s a fascinating window into how the Polaroid pack film process worked, with the light-sensitive layer behind a pull-away black light screen, in front of the white positive sheet and with a pouch of developer chemicals to one side. It’s in no way cheap at somewhere about 10 dollars a shot, but it’s amazing that pack film can be recreated and for enthusiasts it’s a lifeline that keeps their cameras useful.

This isn’t the first time we’ve looked at revitalising a pack film camera, but it’s a lot easier than hacking a Fuji cartridge to do the job.

Continue reading “You Can Now Build Your Own Polaroid-style Pack Film Cartridge” →

The Case For A Technology Aware Lobby Correspondent

November 17, 2023 by Jenny List 24 Comments

We cover all manner of stories here at Hackaday, including awesome hardware hacks, the latest trends and inventions, and in-depth guides to fascinating technologies. We also cover a few news stories from the wider world outside our community, usually when they have some knock-on effect that has an impact on us. Recently this last category of stories has included laws which present a threat to online encryption and privacy in the UK and in the European Union, for example. They’re not the most joyful of news, but it’s vital for everyone with an interest in online matters to be informed about them.

A Long And Inglorious History

A quad flat-pack computer chip, made by VLSI — The infamous Clipper chip. Travis Goodspeed, CC BY 2.0

Those of us who have followed the world of technology will know that badly thought out laws with a negative impact on technology have a long and inglorious history. Some like the infamous backdoored Clipper chip encryption device die an inglorious death as industry or the public succeed in making them irrelevant, but others such as the Digital Millennium Copyright Act or DMCA live on for decades and present an ongoing malign influence. Most recently our ongoing coverage of dubious drone stories included a hefty dose of equally dubious action from lawmakers.

When considering these pieces of legislation it’s easy to characterise the politicians who advance them as gullible idiots easily swayed by any commercial lobbyist with a fistful of cash. But the reality is far more nuanced, while some of them may well be tempted by those lobbyists they are in most cases neither gullible nor foolish. Instead they are better characterised as clueless on technical issues, and thus easily swayed by received opinion rather than by technological reality. If there’s a fault in the system it’s that the essential feedback which provides the checks and balances is missing, and oddly while sitting here writing this story, the responsibility for this comes close to home. The solution doesn’t lie in changing the politicians, but in changing how they are treated by journalists. Continue reading “The Case For A Technology Aware Lobby Correspondent” →

Hackaday Podcast 244: Fake Chips, Drinking Radium, And Spotting Slippery Neutrinos

November 17, 2023 by Kristina Panos 2 Comments

This week, Editor-in-Chief Elliot Williams and Kristina Panos met up to discuss the best hacks of the previous week, at least in our opinions.

After chasing the angry bird away from Kristina’s office, we go to the news and learn that we’re in the middle of a solar conjunction Essentially, the Sun has come between Earth and Mars, making communication impossible for about another week. Did you know that this happens every two years?

Then it’s time for a new What’s That Sound, and although Kristina had an interesting albeit somewhat prompted guess, she was, of course, wrong.

And then it’s on to the hacks, beginning with a really cool digital pen that packs all the sensors. We learned about the world’s largest musical instrument, and compared it to the Zadar Sea Organ in Croatia, which if you’ll recall was once a What’s That Sound.

From there we take a look at fake buck converters, radioactive water as a health fad, and a garage door company that has decided to take their ball and go home. Finally we talk about how slippery neutrinos are, and discuss Tom’s time at JawnCon.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download and savor at your leisure.

Continue reading “Hackaday Podcast 244: Fake Chips, Drinking Radium, And Spotting Slippery Neutrinos” →

That Time NASA Built A Tiny Tank To Pop Shuttle Tires

November 17, 2023 by Tom Nardi 64 Comments

The Space Shuttle has often been called the most complex pieces of machinery ever built, an underhanded compliment if there ever was one. But it’s a claim not strictly limited to the final spacecraft. With a project as far ahead of the technological curve as the Shuttle was in the 1970s, nearly every component and system of the legendary spaceplane required extensive research and development to realize.

A case in point is that the speed and mass of the Shuttle at touchdown required tires that could survive forces far beyond that of a normal airplane. Pumped up to an incredible 350 psi, the space agency estimated each tire had the explosive potential of two and one-half sticks of dynamite. So while testing landing gear upgrades in the 1990s, they cobbled together an RC tank that could “defuse” a damaged tire remotely by drilling holes into it and letting off the pressure. Continue reading “That Time NASA Built A Tiny Tank To Pop Shuttle Tires” →

This Week In Security: SSH, FTP, And Reptar

November 17, 2023 by Jonathan Bennett 3 Comments

It’s time to strap on our propeller beanies, because we’re going to talk crypto. The short version is that some SSH handshakes can expose enough information for a third party to obtain the host’s private signing key. That key is the one that confirms you are connecting to the SSH server you think you are, and if the key validation fails, you get a big warning:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!

The math that makes this warning work is public-private key cryptography. The problem we’re talking about today only shows up in RSA authentication. Specifically those that use the Chinese Remainder Theorem (CRT) to quickly calculate the modulos needed to generate the cryptographic signature. If something goes wrong during that calculation, you end up with a signature that is mathematically related to the secret key in a different way than intended. The important point is that knowing this extra value *significantly* weakens the security of the secret key.

This attack has been known for quite some time, but the research has been aimed at causing the calculation fault through power vaults or even memory attacks like Rowhammer. There has also been progress on using a lattice attack against captured handshakes, to make the attack practical with less known information. The real novel element of this week’s approach (pdf) is that it has been tested against SSH.

The paper’s authors performed weekly scans of the entire IPv4 public network space, capturing the handshake from any listening SSH server, and also had 5 years of historic data to draw from. And the results are mixed. There is a Cisco SSH server string that is extremely common in the dataset, and only once did one of these machines send a miscalculated handshake. Possibly a random ram bit flip to blame. And on the other hand, the string “SSH-2.0-Zyxel SSH server” had so many bad signatures, it suggests a device that *always* sends a miscalculated signature. Continue reading “This Week In Security: SSH, FTP, And Reptar” →