Retrotechtacular: Similarities Of Wave Behavior

similarities-of-wave-behavior

This installment of Retrotechtacular looks at a video lecture that is much more substantive than the usual fare. [Dr. J.N. Shive] was a researcher at Bell Labs at a time when just about every technological breakthrough was coming from that singular collection of minds.

This video, called Similarities of Wave Behavior, was made to help bring students up to speed on the principles of waves. To aid in the experience he invented the apparatus seen in front of him. It’s called a Shive Wave Machine (in the prelude to the video they call it the Shive Wave Generator). Having not taken any physics classes at University we hadn’t seen one of these devices before. It uses a series of horizontal rods connected to each other with torsion wire. When you upset the balance of one of the rods the wire conducts that energy to its neighbors as an energy wave. This turns out to be a perfect representation of wave action whether it be mechanical, electrical, or acoustic. The 28-minute video after the break makes extensive use of the device, and explains concepts in a way that is easy to understand for just about anyone.

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World’s Oldest Functioning Digital Computer Reminds Us Of A Telephone Exchange

This is the WHICH, the Wolverhampton Instrument for Teaching Computing from Harwell. It is the oldest functioning digital computer and thanks to a lengthy restoration process you can go and see it in person at The National Museum of Computing in Milton Keynes (Northwest of London in the UK).

The system was first put into operation in 1951. It’s function is both familiar and foreign. First off, it uses decimal rather than binary for its calculations. And instead of transistors it uses electromechanical switches like are found in older automatic telephone exchanges. This makes for very noisy and slow operation. User input is taken from strips of paper with holes punched in them. As data is accumulated it is shown in the registers using decatrons (which have since become popular in hobby projects). Luckily we can get a look at this in the BBC story about the WITCH.

According to the eLinux page on the device, it was disassembled and put into storage from 1997 until 2009. At that point it was loaned to the museum and has been undergoing cleaning, reassembly, and repair ever since.

[Thanks David]

Retrotectacular: Time Sharing

It’s easy to forget the layer upon layer of technological advances that led to the computers we use today. But this look at the state of the art half a century ago does a good job of reminding us. Here [Fernando J. Corbató] explains the concept of Time-Sharing. He is one of the pioneers of the topic which is now used in every computer system in the world.

Since processors (read: a single core) can only work on one operation at a time, it inherently creates a bottle-neck. This is a huge issue when you consider the cost of the computers used at the time. In the video he mentions $300-$600 an hour. That was in the 1960’s and would roughly equate to about $2300-$4600 in 2012. In other words, there’s big money in using the machine as efficiently as possible.

Early on in the discussion he mentions how programs were loaded and solutions were returned by computers of the day. It started with punch cards, then moved to magnetic tape. At the time this was filmed they had just started using teletype and were hoping to add a graphical interface in the near future. We’ve come a long way but the core principles he’s explaining are still quite important. See both parts of the film after the break.

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Retrotechtacular: 1983’s Answer To Information Overload

We can’t say we ever really thought that the problem with the early 1980’s was too much information in the hands of the people. But this promotional video for the Sceptre Videotex Terminal claims that it is the solution to the information overload of the time. The entire video is embedded after the break.

You use your TV as a display, connecting the hardware to a phone line and using a keyboard for navigation. Perhaps our favorite bit is when the announcer informs us that the secret behind the system is its “vast sources of information”. These include the Miami Herald, the Associated Press, the Wall Street Journal, and Consumer Reports. Just remember that at the time you’d need to hit the local library to access all of those resources. Also, searching them wasn’t a possibility.

But wait, this wasn’t just conceived for news. The system — which was backed by Night-Ridder (a huge Newspaper conglomerate) and AT&T — boasted commerce and banking abilities as well as education services. It’s the vision of the Internet which Ma Bell would have preferred to be in place today.

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Retrotechtacular: Simulating Weather Patterns With A Logic Chip Computer

In 1975, [D. L. Slotnick], CS professor at University of Illinois at Urbana-Champaign faced a problem: meteorologists were collecting a lot more data than current weather simulations could handle. [Slotnick]’s solution was to build a faster computer to run these atmosphere circulation simulations. The only problem was the computer needed to be built quickly and cheaply, so that meant using off-the-shelf hardware which in 1975 meant TTL logic chips. [Ivan] found the technical report for this project (a massive PDF, you have been warned), and we’re in awe of the scale of this new computer.

One requirement of this computer was to roughly 100 times the computing ability of the IBM 360/95 at the Goddard Institute for Space Studies devoted to the same atmospheric computation tasks. In addition, the computer needed to be programmable in the “high-level” FORTRAN-like language that was used for this atmospheric research.

The result – not to overlook the amazing amount of work that went into the design of this machine – was a computer built out of 210,000 individual logic chips at a total cost of $2.7 Million dollars, or about $10 Million in 2012 dollars. The power consumption of this computer would be crazy – about 90 kilowatts, or enough to power two dozen American houses.

We couldn’t find much information if this computer was actually built, but all the work is right there in the report, ready for any properly funded agency to build an amazingly powerful computer out of logic chips.

Retrotechtacular: Recovering Lost Moon Images By Dumpster Diving

In 1966 and 67, NASA launched five probes to image the surface of the moon from orbit, eventually returning over two thousand high-resolution images of future Apollo landing sites and selenogical features to researchers on Earth. After taking its pictures of the moon, developing the film in orbit, and scanning the print with an electron gun and photomultiplier tube, the images were sent to Earth stations and recorded onto magnetic tape with a hugely expensive tape recorder, a state-of-the-art storage system costing $300,000. Researchers poured over these images of another world, made a few 35mm prints and sent the magnetic tapes off to the NASA archives.

Under the care of [Nancy Evans], the tapes sat in a warehouse eventually moving to an abandoned McDonalds at Ames Research Center. In 2005, retired and not bound by NASA, [Nancy] made a plea to preserve this milestone of human spaceflight wasting away under the golden arches which was heard by [Dennis Wingo]. [Wingo] and admin of the NASA Watch website admin [Keith Cowling] drove out to [Nancy]’s house with a truck, picked up the Ampex FR-900 tape drives she had saved in her garage from the trash heap at Eglin Air Force Base and headed to the cache of Lunar Orbiter tapes at Ames.

None of these drives worked, of course. Forty years will do a lot to expensive precision equipment. Luckily, one of the employees at Ames tasked with fixing video equipment had worked on the ancient Ampex drives before. Taking the unbroken parts of these machines and turning them into a single working unit didn’t come easily; again, parts needed to be scavenged from the Ames boneyard.

All this work was worth it for [Cowling], [Wingo], and [Evans] when the first image – an Earthrise picture seen above (sans the obvious Photoshoppery) – appeared on their monitor. Later, an amazing oblique shot of Copernicus crater was recovered.

In the years since these first images from the LOIRP project were released, many more images have been made available. These images are actually comparable to the Lunar Reconnaissance Orbiter, launched in 2012. Not bad for 45-year-old hardware that has since crashed into the moon.

As for what the future holds for the still-magnetized images from the Lunar Orbiter program, [Dennis Wingo] says they’re considering putting up a Kickstarter to close the gap between the necessary funding and what NASA provides. We’ll be sure to post a link when that happens.

via boingboing

Retrotechtacular: The Miracle Of Vacuum Tubes

We take our digital life for granted these days, but back in 1943 it was vacuum tubes, not transistors, which made it all possible. This video on the types and industrial uses of vacuum tubes was sent into the tips line by [Polar Bear]. The nearly 70-year-old video is part of a collection preserved by the New Jersey Amateur Radio Club.

The video was underwritten by Westinghouse, and as you can expect it has a bit of propaganda spin for the company. The time period in which the reel was produced is also telling. Coming about two years after the attack on Pearl Harbor, the applications for technology of the time are almost all military in focus. But we’re sure you’ll be entertained by both the film style and the tech explanation. It’s something of a How It’s Made of yesteryear. All twenty-one minutes of it are found embedded after the break.

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