Author: Jenny List

3427 Articles

Flux, From Scratch

January 29, 2024 by 55 Comments

Soldering flux is (or at least, should be) one of the ubiquitous features of any electronics bench. It serves the purpose of excluding oxygen from a solder joint as it solidifies, and in most cases its base is derived from pine rosin. Most of us just buy flux, but [pileofstuff] is having a go at making his own.

He starts with a block of rosin and a couple of different solvents. Isopropanol we’re happy with, but perhaps using methanol for something to be vaporized within breathing distance isn’t something we’d do. At about 25% rosin to solvent ratio the result is a yellow liquid flux, which he tests against some commercial fluxes. The result is a reasonable liquid flux, something which perhaps shouldn’t be too much of a surprise, and is a handy piece of information to store away should we ever be MacGuyver-like stuck in a pine forest with a need to save the day with electronics.

It would be interesting to try the same technique but with a solvent selected to soften the rosin for a paste flux, and perhaps any chemists among our readership could enlighten us about just what rosin is beside the heavy fractions left after extracting the volatiles from pine resin.

In the past we’ve taken a close look at how solder really works.

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Bringing An IBM Butterfly Laptop Back From The Dead

January 28, 2024 by 8 Comments

Among all the laptops produced over the last few decades, there is one which rises above the rest and which has retained an appeal long after its meager computing resources became obsolete. It’s the IBM 701c, the famous “Butterfly” laptop, whose fold-out keyboard still gives it star  quality, and [John Graham-Cumming] has documented the restoration of one from the tattered remains of two scrap examples.

The two laptops in question were someone else’s never-started project, and were in a sorry state. The flexible cables were in poor condition, and the 1990s Ni-MH batteries had leaked and damaged both circuits and case. We were unaware that NiMH leakage could damage plastic, but the parts of these machines were significantly damaged.

One had a working mainboard, the other a working modem card. One keyboard was in pretty bad shape, the other was complete. Of the pair there was a double super twisted nematic (DSTN) display and a more contemporary thin film transistor (TFT) panel. Be thankful if you have never had to use a DSTN laptop, as they were truly awful. From this pile of parts a working machine could be made, and with a new CMOS battery, that cable repair, and a repaint, he was ready. Or at least, as he says, ready for 1995.

This isn’t the first 701c restoration we’ve seen, and within reason, it’s even possible to give them a retro processor upgrade.

POTS At A Hacker Camp

January 25, 2024 by 1 Comment

For those of us off the Atlantic coast of Europe it’s a frigid winter as our isles are lashed by continuous storms. Summer seems a very long time ago, and the fun of the EMF 2022 hacker camp is an extremely distant memory. But the EMF team have been slowly releasing videos from the talks at that camp, the latest of which comes from [Matthew Harrold]. He was the force behind the public POTS phone network at the camp, providing anyone within range of one of his endpoints with the chance to have a wired phone line in their tent.

We’d love to imagine a mesh of overhead wires converging on a Strowger mechanical exchange somewhere on the field, but in a more practical move he used an array of redundant Cisco VOIP gear, and a multi-modem rack to provide dial-up services. Even then there were a few hurdles to overcome, but on the field it was definitely worth it as an array of unusual phone kit was brought along by the attendees. Our favourite is the Amstrad eMailer, an all-in-one phone and internet appliance from a couple of decades ago which perhaps due to its expensive pay as you go model, failed commercially. The video is below the break.

It’s a good time for this talk to come out, because it’s reminded us that the next EMF camp is on this summer. Time to dust off an old phone to bring along. Meanwhile, we’ve seen [Matthew] before, as he refurbished a sluggish dial mechanism.

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Another Chance To Revive Your Nabaztag

January 23, 2024 by 17 Comments

The early history of home internet appliances was replete with wonderful curios as a new industry sought to both find a function for itself and deliver something useful with whatever semiconductors were available nearly two decades ago. A favourite of ours is the Nabaztag, a French-designed information appliance in the form of a cute plastic rabbit whose ears would light up and move around as it delivered snippets of information.

The entity behind the Nabaztag folded and the servers went away years ago of course, but the original designer [Olivier Mével] never gave up on his creation. Back in 2019 he created an updated mainboard for the device packing a Raspberry Pi Zero W, which has been released in a series of crowdfunding campaigns. If you have a Nabaztag and haven’t yet upgraded, you can snag one now as the latest campaign has started.

We took a look at the Nabaztag back in 2020, at the time with out bricked original unit. Happily a year later we were able to snag one of the upgrades, so it’s now happily keeping us up to date with the time, weather, and other fun things. The upgrade motherboard is designed to slot into the same place as the original and mate with all its connectors, and even comes with that annoying triangle screwdriver. If you want to stand out against all the Alexa and Google Home owners, dig out your cute rabbit from the 2000s and give it this board!

640k Was Never Enough For Anyone: How DOS Broke Free

January 21, 2024 by 38 Comments

On modern desktop and laptop computers, there is rarely a need to think about memory. We all have many gigabytes of the stuff, and it’s just there. Our operating system does the heavy lifting of working out what goes where and what needs to be paged to disk, and we just get on with reading Hackaday, that noblest of computing pursuits. This was not always the case though, and for early PCs in particular the limitations of the 8086 processor gave the need for some significant gymnastics in search of an extra few kilobytes. [Julio Merion] has an interesting run-down of the DOS memory map, and how memory expansion happened on computers physically unable to see much of it.

The 8086 has a 20-bit address bus, giving it access to a maximum of 1 megabyte. When IBM made the PC they needed space for the BIOS, the display, and the various accessory ROMs intended to come with expansion cards. Thus they allocated a maximum 640k of the map for RAM, and many early machines shipped with much less than that. The quote from Bill Gates about 640k being enough for anyone is probably apocryphal, but it was pretty clear as the 1980s wore on that more would be needed. The post goes into how memory expansion worked, with a 64k page mapped to switchable RAM on a card, and touches on how DOS managed extended memory above 1 Mb on the later processors that supported it. We dimly remember there also being a device driver that would map the unused graphics memory as EMS when the graphics card was running in text mode, but such horrors are best left behind.

Of course, some of the tricks to boost RAM were nothing but snake oil.

8086 header: Thomas Nguyen, CC BY-SA 4.0

Creators Can Fight Back Against AI With Nightshade

January 21, 2024 by 78 Comments

If an artist were to make use of a piece of intellectual property owned by a large tech company, they risk facing legal action. Yet many creators are unhappy that those same tech companies are using their IP on a grand scale in the form of training material for generative AI. Can they fight back?

Perhaps now they can, with Nightshade, from a team at the University of Chicago. It’s a piece of software for Windows and MacOS that poisons an image with imperceptible shading, to make an AI classify it in an entirely different way than it appears.

The idea is that creators use it on their artwork, and leave it for unsuspecting AIs to assimilate. Their example is that a picture of a cow might be poisoned such that the AI sees it as a handbag, and if enough creators use the software the AI is forever poisoned to return a picture of a handbag when asked for one of a cow. If enough of these poisoned images are put online then the risks of an AI using an online image become too high, and the hope is that then AI companies would be forced to take the IP of their source material seriously.

For this to work it depends on enough creators taking up and using the software, but we are guessing that an inevitable result will be an arms race between AIs and image poisoners. One thing is certain though, as the AI hype has fueled such a growth in generative AI systems, creators, whether they be major publishers, your favourite human-generated tech news website, or someone drawing a cartoon strip in their bedroom, deserve not to have their work stolen in this way.

The Giant LEGO You Always Wanted To Play With

January 20, 2024 by 18 Comments

The interlocking LEGO bricks are probably one of the most versatile toys to come out of the 20th century, but aside from the Duplo larger-sized version for smaller kids, they don’t come in what you might term grown-up sizes. This has not deterred [Veranda Vikings] though, who have come up with the fantastic idea of giant LEGO bricks made from snow.

Making them is simplicity itself given enough depth of the white stuff, simply press the lid of one of those plastic LEGO storage bins into some fresh snowfall hard enough to compact  your brick, and then lift clear a perfect icy 2 by 2 brick. Most of the post is devoted to the building escapades of some very happy kids, and we can’t help envying them the opportunity. It appears that like the LEGO fries in the cafe at Legoland in Bilund, these bricks don’t quite interlock. We think that it would be possible to press the LEGO storage lid into the bottom of them though, perhaps some readers would like to experiment.

Either way, this is a hack to warm the hearts of readers worldwide, whether they live in a country with snow or not. We’re surprised Lego themselves haven’t caught on to the idea, and sold giant snow-brick moulds.