Retrotechtacular: Critical Code Reading, 70s Style

January 5, 2023 by 30 Comments

Anyone who has ever made a living writing code has probably had some version of the following drilled into their head: “Always write your code so the next person can understand it.” Every single coder has then gone on to do exactly the opposite, using cryptic variables and bizarre structures that nobody else could possibly follow. And every single coder has also forgotten the next part of that saying — “Because the next person could be you” — and gone on to curse out an often anonymous predecessor when equally inscrutable code is thrust upon them to maintain. Cognitive dissonance be damned!

It’s a tale as old as time, or at least as old as programming has existed as a profession. And by 1975, poorly written code was enough of a problem that an outfit called Edutronics put together the animated gem Critical Program Reading: Structuring an Unstructured Program. It’s apparently Part 1 of a larger series on structured programming techniques, and comes to us by way of [Alec Watson], host of Technology Connections on YouTube, by way of his second channel, the delightfully named Technology Connextras.

The film’s three minimally animated characters, each of whom could have been the villain in an episode of Scooby Doo, are tasked by a stern-sounding narrator to analyze a fragment of pseudocode that’s written in a concoction of COBOL, PL/1, and a bunch of other languages. The code is a hot mess, but our heroes muddle through it line by awful line, making it more readable by guessing at more descriptive variable names, adding structured elements, and making logical changes to improve the program’s flow. The example code is highly contrived, to be sure, but the business logic becomes much clearer as our team refactors the code and makes it far more approachable.

For as much as languages have changed since the 1970s, and with all the progress we’ve made in software engineering, the lessons presented in this film are still surprisingly relevant. We loved a lot of the little nuggets dropped along the way, like “Consistency aids understanding,” and “Use symbols in a natural way.” But we will take exception with the statement “Wrong means poor structure” — we’ve written seen plenty of properly structured code that didn’t work worth a damn. We also enjoyed the attempt at socially engineering a less toxic work environment: “Use tact in personal criticisms.” If only they could learn that lesson over at Stack Overflow.

It’s not clear where [Alec] found this 16-mm film — we’d sure like to hear that story — but it’s a beauty and we’re glad he took the time to digitize it. We’re consistently amazed at his ability to make even the most mundane aspects of technology endlessly fascinating, and while this film may be a bit off from his normal fare, it’s still a great find. Continue reading “Retrotechtacular: Critical Code Reading, 70s Style” →

The Dawn Of Synthetic Milk: When Milk Becomes More Like Beer

January 5, 2023 by 85 Comments

What would we do without milk in modern day society? Although lactation originally evolved as a way to provide a newborn mammal with nutrients and the other essentials during the first weeks of their life, milk has for thousands of years now been a staple food in human cultures. Whether from cows, camels, sheep or other mammals, each year humans consume many liters of this mythical substance, with our galaxy’s name – the Milky Way –  coming courtesy of Greek mythology and a spilled milk incident.

A major issue with mammalian milk, however, is that it is only produced by females for a certain time after giving birth, which requires for example a dairy cow to constantly go through pregnancies, which is both cumbersome and not very animal-friendly. Simultaneously, the newborn offspring cannot drink this milk, but must be provided with an alternative. For these reasons synthetic milk is becoming an increasingly more popular animal- and environmentally-friendly alternative.

For years now, companies such as US-based Perfect Day are producing milk that’s for all intents and purposes identical to cow milk, with the added advantage of being free of lactose and other problematic additions. The best part of this all? It’s all done with existing fermentation techniques.

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A Practical Glue Stick Oscillator

January 5, 2023 by 15 Comments

A few months ago we brought you some experiments from [Bill Meara, N2CQR], in which he investigated the use of a glue stick as the former for a permeability tuned inductor. His set-up was very much in the spirit of experimentation, and we’re very pleased to now see [Nick, M0NTV] has taken the idea and demonstrated it for the 7 MHz, or 40 meter, amateur radio band.

The result can be seen in the video below the break, and is housed in a tin enclosure that we’re guessing once contained toffees. The oscillator circuit comes courtesy of [Ashar Farhan VU2ESE] of BitX transceiver fame, but we’re most interested in the glue stick coil former which makes use of a small bracket for stability. With the glue removed, he’s mounted a ferrite ring in its glue carrier which is moved in and out of the coil. We’re guessing this could also be done with other permeability-altering materials, for example we’d follow [VU2ESE]’s lead and try a piece of brass.

The knurled glue feed knob protrudes through a hole in the tin, and we’re guessing there’s enough separation for an operator’s hand not to drag the frequency too much. All in all given that variable capacitors are now something of a rarity, it makes for a useful demonstration of a very cheap replacement. Meanwhile, you can read our notes on [N2CQR]’s work here.

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Excuse Me, Your Tie Is Unzipped

January 5, 2023 by 102 Comments

If you ask your typical handyperson what’s the one thing you need to fix most things, the answer might very well be duct tape. But second place — and first place in some circles — would have to be zip ties. These little wonders are everywhere if you look for them. But they are a relatively recent invention and haven’t always had the form they have today.

The original zip tie wasn’t called a zip tie or even a cable tie. In 1958 they were called Ty-Raps and produced by a company called Thomas and Betts. Originally meant to improve aircraft wiring harnesses, they found their way into various electronic equipment and packaging uses. But they’ve also become helpful in very unusual places too. A policeman trying to round up rioters would have problems carrying more than a few conventional handcuffs. But flexible cuffs based on zip ties are lightweight and easy to carry. Colon surgeons sometimes use a modified form of zip tie during procedures.

History

Maurus Logan worked for the Thomas and Betts company. In 1956, he was touring an aircraft manufacturing plant. Observing a wiring harness being put together on a nail board, similar to how car harnesses are made, he noted that the cables were bundled with waxed twine or nylon cord. A technician had to tie knots in the cord, sometimes cutting their fingers and often developing calluses. In addition, the twine was prone to fungal growth, requiring special treatment.

Logan kept turning the problem over in his mind and tried various approaches. By 1958, he had a patent for the Ty-Rap. The tie was lightweight, easy to install, easy to remove, and inexpensive.

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N-O-D-E Unveils Slick Tech News Site

January 5, 2023 by 24 Comments

There’s probably some axiom in professional journalism that says you shouldn’t give out free advertisement to your competitors — but since none of us have any formal training in this kind of thing and are just making it up as we go along — we’re more than happy to plug the brand-new MOSFET.net.

We like the option to ignore Reality.

Created by the mysterious hacker [N-O-D-E], the site is exceptionally minimal, providing an experience not entirely unlike a feed reader. Each story has a main image, a few sentences that describe what it’s about, and the ever-important link to the original source. There’s even a color filter applied on the images so they aren’t jarring when compared to the site’s monochrome color scheme. (If that all sounds familiar, it’s because Hackaday came up with the idea 18 years ago. But it’s cool, we’re not salty or anything.)

In all seriousness, the site looks very well done and will no doubt be a great resource for the community. A particularly interesting feature is that entries expire automatically after 30 days. This speaks to the goal [N-O-D-E] has for MOSFET.net — it’s designed to show you relevant tech news, and literally nothing else. The focus and simplicity is beautiful.

Here’s wishing all the luck to [N-O-D-E] in this new venture. We know better than most that it can be a difficult and sometimes thankless job, but we wouldn’t still be doing it all these years if it wasn’t worth the effort. The tech world is always growing and there’s plenty of room for everyone. In fact, a recent peek at the analytics revealed that Hackaday got more views in 2022 than at any time in its history. As far as we’re concerned, the future looks bright for everyone.

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The Flight Of The Dremel

January 5, 2023 by 12 Comments

A few months ago we featured a model aircraft whose power plant came courtesy of an angle grinder. It was the work of [Peter Sripol], and it seems he was beseiged by suggestions afterwards that he might follow it up with a helicopter built using a Dremel rotary tool. Which he duly did, and the results can be seen in the video below the break.

The Dremel itself requires a gearing to drive the balsa-bladed rotor, and a tail rotor is mounted with its own motor at the end of a boom. The video has many entertaining failures which see him arrive at a set of balancing arms and a tailplane for stability. The result is a helicopter that flies after a fashion, and is even able to stay aloft for a few seconds rather than crashing to earth.

The machine lacks the full rotor pitch control of its commercial bretheren, indeed the only control is directional via the tail rotor. Still it deserves top marks for entertainment alone, and we wouldn’t mind a go ourselves. The original angle grinder craft can be seen here.

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A White-Light Laser, On The Cheap

January 4, 2023 by 51 Comments

Lasers are known for the monochromatic nature of their light, so much so that you might never have thought there could be such a thing as a white laser. But in the weird world of physics, a lot of things that seem impossible aren’t really, as demonstrated by this dirt-cheap supercontinuum laser.

Of course, we’re not experts on lasers, and certainly not on non-linear optics, so we’ll rely on [Les Wright]’s video below to explain what’s going on here. Basically, a “supercontinuum” is just the conversion of a monochromatic source to a broader spectral bandwidth. It’s a non-linear optical process that’s usually accomplished with expensive bits of kit, like photonic crystal fibers, which are optical fibers with an array of tiny air-filled holes running down their lengths. Blast a high-intensity monochromatic laser down one end, and white light comes out the other end.

Such fibers are obviously fantastically expensive, so [Les] looked back in the literature and found that a simple silica glass single-mode fiber could be used to produce a supercontinuum. As luck would have it, he had been experimenting with telecom fibers recently, so along with a nitrogen laser he recovered from a Dumpster, he had pretty much everything he needed. The final setup uses the UV laser to pump a stilbene dye laser, which shoots a powerful pulse of 426 nanometer light into about 200 meters of fiber, and produces a gorgeous supercontinuum containing light from 430 nm to 670 nm — pretty much the entire visible spectrum.

It’s great to see projects like this that leverage low-cost, easy-to-source equipment to explore esoteric physics concepts.

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