Retrotechtacular

275 Articles

3D-printed wall builder, circa 1930s

Retrotechtacular: 3D-Printed Buildings, 1930s Style

October 6, 2021 by 35 Comments

Here we are in the future, thinking we’re so fancy and cutting edge with mega-scale 3D printers that can extrude complete, ready-to-occupy buildings, only to find out that some clever inventor came up with essentially the same idea back in the 1930s.

The inventor in question, one [William E. Urschel] of Valparaiso, Indiana, really seemed to be onto something with his “Machine for Building Walls,” as his 1941 patent describes the idea. The first video below gives a good overview of the contraption, which consists of an “extruder” mounted on the end of a counterweighted boom, the length of which determines the radius of the circular structure produced. The boom swivels on a central mast, and is cranked up manually for each course extruded. The business end has a small hopper for what appears to be an exceptionally dry concrete or mortar mix. The hopper has a bunch of cam-driven spades that drive down into the material to push it out of the hopper; the mix is constrained between two rotating disks that trowel the sides smooth and drive the extruder forward.

The device has a ravenous appetite for material, as witnessed by the hustle the workers show keeping the machine fed. Window and door openings are handled with a little manual work, and the openings are topped with lintels to support the concrete. Clever tools are used to cut pockets for roof rafters, and the finished structure, complete with faux crenellations and a coat of stucco, looks pretty decent.

Continue reading “Retrotechtacular: 3D-Printed Buildings, 1930s Style” →

Retrotechtacular: The Dangers Of Confined Spaces

September 17, 2021 by 31 Comments

Many people find themselves working in confined spaces every day, whether it be in sewer systems, drains, or other tight spots. These areas come with their own unique risks to life and limb that must be carefully considered in order to avoid disaster.

To this end, the Worker’s Compensation Board of British Columbia, known as WorkSafe BC, produced a video on the dangers of working in these areas. Confined Spaces, Deadly Spaces highlights how these areas can kill, and the right way to work around these hazards.

Continue reading “Retrotechtacular: The Dangers Of Confined Spaces” →

An Amiga computer at NASA

Retrotechtacular: Amiga Pips The PC For Mission-Critical Computing At NASA

August 16, 2021 by 46 Comments

In 1986, a group of NASA engineers faced a difficult choice in solving their data processing woes: continue tolerating the poor performance of PC architecture, or pony up the cash for exotic workstations. It turns out that the Commodore Amiga was an intriguing third choice, except for the fact that, paradoxically, it didn’t cost enough. Oh, and Apple wanted nothing to do with any of it.

Steeped in history, NASA’s Hangar AE is a hub for launch vehicle telemetry and other mission communications, primarily during prelaunch phases for launches at Cape Canaveral. Throughout the late 20th century, Hangar AE supported NASA launch vehicles in all shapes and sizes, from the Atlas-Centaur evolutions to the mighty Titan family. It even supported user data from the Space Shuttle program. Telemetry from these missions was processed at Hangar AE before being sent out to other NASA boffins, and even transmitted worldwide to other participating space agencies.

Coming down from decades of astronomical levels of funding, the 1980s was all about tightening the belt, and NASA needed budget solutions that didn’t skimp on mission safety. The Commodore Amiga turned out to be the right choice for processing launch vehicle telemetry. And so it was still, when cameras from the Amiga Atlanta group were granted permission to film inside Hangar AE.

Continue reading “Retrotechtacular: Amiga Pips The PC For Mission-Critical Computing At NASA” →

Retrotechtacular: LA’s Hilarious Subway Safety Film From 1992

August 13, 2021 by 17 Comments

Subways! They’ve been around for an awfully long time; almost as long as modern railways themselves, believe it or not. Building underground was undertaken in earnest by those in the 19th century, who set out to build networks of stations to allow residents to get around a city quickly and effectively.

That fact should stick in your mind as you sample this glorious retro video from 1992. “L.A. Underground – Safety in the Extreme” is a guide for Californians, aiming to educate residents about the new B Line subway that opened the following year. The video acts as if the subway is a new fangled, mysterious thing, with a couple of confusing off-the-wall moments as well. If you’re a transport enthusiast or get excited about weird public films, this one’s for you.

Continue reading “Retrotechtacular: LA’s Hilarious Subway Safety Film From 1992” →

Retrotechtacular: Understanding Protein Synthesis Through Interpretive Dance

August 1, 2021 by 8 Comments

With the principles of molecular biology very much in the zeitgeist these days, we thought it would be handy to provide some sort of visual aid to help our readers understand the complex molecular machines at work deep within each cell of the body. And despite appearances, this film using interpretive dance to explain protein synthesis will teach you everything you need to know.

Now, there are those who go on and on about the weirdness of the 1960s, but as this 1971 film from Stanford shows, the 60s were just a warm-up act for the really weird stuff. The film is a study in contrasts, with the setup being provided by the decidedly un-groovy Paul Berg, a professor of biochemistry who would share the 1980 Nobel Prize in Medicine for his contributions to nucleic acid research. His short sleeves and skinny tie stand in stark contrast to the writhing mass of students capering about on a grassy field, acting out the various macromolecules involved in protein synthesis. Two groups form the subunits of the ribosome, a chain of ballon-headed students act as the messenger RNA (mRNA) that codes for a protein, and little groups standing in for the transfer RNA (tRNA) molecules that carry the amino acids float in and out of the process.

The level of detail, at least as it was understood in 1971, is impressively complete, with soloists representing things like T-factor and the energy-carrying molecule GTP. And while we especially like the puff of smoke representing GTP’s energy transfer, we strongly suspect a lot of other smoke went into this production.

Kitsch aside, and with apologies to Lewis Carroll and his Jabberwock, you’ll be hard-pressed to find a modern animation that captures the process better. True, a more traditional animation might make the mechanistic aspects of translation clearer, but the mimsy gyre and gimble of this dance really emphasize the role random Brownian motion plays in macromolecular processes. And you’ll never see the term “tRNA” and not be able to think of this film.

Continue reading “Retrotechtacular: Understanding Protein Synthesis Through Interpretive Dance” →

Retrotechtacular: Mechanical TV From The People Who Made It Happen

July 31, 2021 by 12 Comments

If we have a television in 2021 the chances are that it will be a large LCD model, flat and widescreen, able to display HD images in stunning clarity. Before that we’d have had a CRT colour TV, them maybe our parents grew up with a monochrome model. Before those though came the first TVs of all, which were mechanical devices that relied on a spinning disk to both acquire and display the image. The BBC Archive recently shared a vintage clip from 1970 in which two of the assistants of [John Logie Baird], the inventor of the first demonstrable television system, demonstrated its various parts and revealed its inner workings.

We’ve covered the Nipkow scanning disk in a previous article, with its characteristic spiral of holes. We see the original Baird Televisor, but the interesting part comes as we move to the studio. Using the original equipment they show a dot of light traversing the presenter’s face to scan a picture before taking us to a mock-up of the original studio. Here there’s a surprise, because instead of the camera we’d expect today there is a Nipkow disk projector which traverses the subject sitting in the dark. A bank of photocells above the projector senses the reflected light, and returns a video signal.

The resulting low-resolution pictures had a low enough bandwidth to be broadcast over an AM radio transmitter, and for a tiny 30-line picture in the glowing pink of a neon light they provide a surprising amount of detail. With such a straightforward principle it’s not surprising that they’ve appeared in a few projects on these pages, including an Arduino driven colour video monitor, and a POV clock. Take a look at the video below the break.

Continue reading “Retrotechtacular: Mechanical TV From The People Who Made It Happen” →

Retrotechtacular: Nuvistor, Vacuum’s Last Gasp

July 21, 2021 by 51 Comments

In 2021 all our electronics are solid state, in that they exclusively use semiconductor devices as their active components. Some of us may experiment with vacuum tubes, but only for curiosity or aesthetic purposes. Semiconductors have overtaken vacuum devices in all but the rarest of niche applications due to their easier design requirements, greater reliability, lower cost, and increased performance.

It was not always this way though, and there was a period at the start of the semiconductor era when transistors and vacuum tubes existed together side-by-side and competed directly. Vacuum tube manufacturers continued to create new devices into the 1970s, and in doing so they pushed the boundaries of their art in unprecedented directions. [David W Knight] has a page dedicated to the Nuvistor, something his calls the “final evolution of the thermionic valve”. His comparison photo seen above shows a Nuvistor on the left — a miniature vacuum tube you’ve likely never seen before.

Continue reading “Retrotechtacular: Nuvistor, Vacuum’s Last Gasp” →