Hackaday Links: August 13, 2017

August 13, 2017 by Brian Benchoff 29 Comments

We found the most boring man on the Internet! HTTP Status Code 418 — “I’m a teapot” — was introduced as an April Fools Joke in 1998. Everyone had a good laugh, and some frameworks even implemented it. Now, the most boring man on the Internet and chairman of the IETF HTTP working group is trying to get 418 removed from Node and Go. There is an argument to removing code 418 from pieces of software — it gums up the works, and given only 100 code points for a client error, with 30 of them already used, we don’t really have space for a joke. There’s a solution, though: someone has submitted a request to register 418 as ‘I’m a teapot’.

The Travelling Hacker box is a migratory box of random electronic junk. The box has traveled across the United States several times, and earlier this year it started across Canada — from Vancouver to St. Johns — to begin an International journey. The box is now missing, and I’m out. I’m turning this one over to the community. There are now several rogue boxes traveling the world, the first of which was sent from [Sophi] to [jlbrian7] and is now in Latvia with [Arsenijs]. The idea of the Travelling Hacker Box is now up to you — organize your own, and share random electronic crap.

Bluetooth 5 is here, or at least the spec is. It has longer range, more bandwidth, and advertising extensions.

Guess what’s on the review desk? The Monoprice Mini Delta! If you have any questions you’d like answered about this tiny, very inexpensive printer, put them in the comments. I only have some first impressions, but so far, it looks like extending the rails (to make a taller printer) is more difficult than it’s worth. That’s not to say it’s impossible, but with the effort required, I could just print another printer.

Interested in PCB art? [Drew] found someone doing halftone art with PCBs. This is a step up from nickels.

Indiana University is getting rid of some very, very cool stuff in a government auction. This device is listed as a ‘gantry’, but that’s certainly not what it is. There have been suggestions that these devices are a flight sim, but that doesn’t sit quite right either. It’s several thousand pounds of metal, with the minimum bid of $2.00 at the time of this writing. Any guesses on what this actually is?

Testing Distance Sensors

August 11, 2017 by John Baichtal 40 Comments

I’m working on a project involving the need to precisely move a tool based on the measured distance to an object. Okay, yeah, it’s a CNC mill. Anyway, I’d heard of time of fight sensors and decided to get one to test out, but also to be thorough I wanted to include other distance sensors as well: a Sharp digital distance sensor as well as a more sophisticated proximity/light sensor. I plugged them all into a breadboard and ran them through their paces, using a frame built from aluminum beams as a way of holding the target materials at a specific height.

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Books You Should Read: IGNITION!

August 11, 2017 by Donald Papp 38 Comments

Isaac Asimov described the business of rocket fuel research as “playing footsie with liquids from Hell.” If that piques your interest even a little, even if you do nothing else today, read the first few pages of IGNITION! which is available online for free. I bet you won’t want to stop reading.

IGNITION! An Informal History of Liquid Rocket Propellants is about how modern liquid rocket fuel came to be. Written by John D. Clark and published in 1972, the title might at first glance make the book sound terribly dry — it’s not. Liquid rocket fuel made modern rocketry possible. But most of us have no involvement with it at all besides an awareness that it exists, and that makes it easy to take for granted.

Most of us lack any understanding of the fact that its development was the result of a whole lot of hard scientific work, and that work required brilliance (and bravery) and had many frustrating dead ends. It was also an amazingly dangerous business to be in. Isaac Asimov put it this way in the introduction:

“[A]nyone working with rocket fuels is outstandingly mad. I don’t mean garden-variety crazy or a merely raving lunatic. I mean a record-shattering exponent of far-out insanity.

There are, after all, some chemicals that explode shatteringly, some that flame ravenously, some that corrode hellishly, some that poison sneakily, and some that stink stenchily. As far as I know, though, only liquid rocket fuels have all these delightful properties combined into one delectable whole.”

At the time that the book was written and published, most of the work on liquid rocket fuels had been done in the 40’s, 50’s, and first half of the 60’s. There was plenty written about rocketry, but very little about the propellants themselves, and nothing at all written about why these specific substances and not something else were being used. John Clark — having run a laboratory doing propellant research for seventeen years — had a unique perspective of the whole business and took the time to write IGNITION! An Informal History of Liquid Rocket Propellants.

Liquid rocket propellant was in two parts: a fuel and an oxidizer. The combination is hypergolic; that is, the two spontaneously ignite and burn upon contact with each other. As an example of the kinds of details that mattered (i.e. all of them), the combustion process had to be rapid and complete. If the two liquids flow into the combustion chamber and ignite immediately, that’s good. If they form a small puddle and then ignite, that’s bad. There are myriad other considerations as well; the fuel must burn at a manageable temperature (so as not to destroy the motor), the energy density of the fuel must be high enough to be a practical fuel in the first place, and so on.

The actual process of discovering exactly what materials to use and how precisely to make them work in a rocket motor was the very essence of the phrase “the devil is in the details.” For every potential solution, there was a mountain of dead-end possibilities that tantalizingly, infuriatingly, almost worked.

The first reliable, workable propellant combination was Aniline and Red Fuming Nitric Acid (RFNA). “It had the one – but magnificent – virtue that it worked,” writes Clark. “Otherwise it was an abomination.” Aniline was difficult to procure, ferociously poisonous and rapidly absorbed through skin, and froze at an inconvenient -6.2 Celsius which limited it to warm weather only. RFNA was fantastically corrosive, and this alone went on to cause no end of problems. It couldn’t be left sitting in a rocket tank waiting to be used for too long, because after a while you wouldn’t have a tank left. It needed to be periodically vented while in storage. Pouring it gave off dense clouds of remarkably toxic gas. This propellant would go on to cause incredibly costly and dangerous problems, but it worked. Still, no one wanted to put up with any of it one moment longer than they absolutely had to. As a result, that combination was not much more than a first step in the whole process; there was plenty of work left to do.

By the mid-sixties, liquid rocket propellant was a solved problem and the propellant community had pretty much worked themselves out of a job. Happily, a result of that work was this book; it captures history and detail that otherwise would simply have disappeared.

Clark has a gift for writing, and the book is easy to read and full of amusing (and eye-widening) anecdotes. Clark doesn’t skimp on the scientific background, but always in an accessible way. It’s interesting, it’s relevant, it’s relatable, and there is plenty to learn about how hard scientific and engineering development actually gets done. Download the PDF onto your favorite device. You’ll find it well worth the handful of evenings it takes to read through it.

Getting Started With Blinking Lights On Old Iron

August 10, 2017 by Al Williams 30 Comments

If you ever go to a computer history museum, you’ll be struck by how bland most modern computers look. Prior to 1980 computers had lights and switches, and sometimes dials and meters. Some had switchboard-like wiring panels and some even had oscilloscope-like displays. There’s something about a machine with all those switches and lights and displays that gets your hacker juices flowing. Have you ever wanted to get started in retrocomputing? Is it difficult? Do you need a lot of money? That depends on what your goals are.

There are at least three ways you can go about participating in retrocomputing: You can pony up the money to buy actual antique computers, you can build or buy old computers recreated with anywhere from zero to one hundred percent of period-authentic components, or you can experiment with emulators that run on a modern computer. As a hybrid of the second and third option there are also emulations in FPGAs.

You can see that the first option can be very expensive and you will probably have to develop a lot of repair and restoration skills. Watching [Mattis Lind] twiddle the bits on an actual PDP-8 in the clip above is great, but you’ll need to work up to it. The two techniques which get you going without the original hardware don’t have to break the bank or even cost anything presuming you already have a PC.

Although some sneer at emulation, for some machines it is almost the only way to go. You couldn’t buy the original EDSAC, for example. It is also a good way to get started without a lot of expense or risk. But regardless of how you do it, there’s one thing in common: you have to know how to operate the thing.

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2017’s VCF West Is Another Beloved Trip Down Memory Lane

August 10, 2017 by Sonya Vasquez 20 Comments

This past weekend, another smashing round of the Vintage Computer Festival was held at the Computer History Museum in Mountainview. As always, VCF West gathers the sages and lords of vintage computers onto a common ground to talk old-school hardware. It also draws in a collection of unique artifacts, many of which either still work, have been brought back to life, or have otherwise been reincarnated through a modern means. [Bil Herd] and I dropped in to join the crowd, and I snagged a few pics of some new faces and pieces that have been added to the experience since last year.

[Foone’s] Digital Media Archiving

Up first on our bucket list was [Foone], a librarian of digital media archiving. Outside of VCF, he runs a digital media backup gig to help folks backup their niche, often-failing, disk formats into something more modern. His drive for doing this backup features a special “reread” capability, where the file is actually reread dozens of time to validate that the right information was pulled from it.

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Friday Hack Chat: Crypto Challenge

August 9, 2017 by Brian Benchoff 2 Comments

It’s the middle of August, and that means all the hackers are back from DEF CON, safe in their hoodies, with memories of smoke-filled casinos, interesting talks, and, most importantly, crypto challenges.

This year was an ‘off’ year for DEF CON. There was an official badge, but it wasn’t electronic (which no one expected), and there was no crypto challenge (which no one saw coming). Nevertheless, there was already a vibrant community of badge builders, and the crypto nerds of DEF CON were satisfied by PCB locks from the Crypto and Privacy village, Benders, and Darknet phone dials this year.

How were these crypto challenges constructed? That’s the subject of this week’s Hack Chat. This Friday, we’re going to be sitting down with a member of DEF CON’s Crypto and Privacy village on how these curious codes are constructed, how a winner is determined, and the techniques used to solve these challenges.

This week, we’ll be talking about how crypto challenges actually work, how to put crypto in firmware, on laser-engraved acrylic plates, and in silkscreen on a PCB. We’ll be talking about how crypto challenges are created, and how you solve them. Special attention will be paid to testing a crypto challenge; that is, how do you make sure it’s solvable when you already know how to solve it?

Although this Hack Chat is only going to last an hour, there’s no possible way we could cover all the tips, tricks, and techniques of creating a crypto challenge in that time. If you’d like some further reading, [L0sT] showed up at our 10th anniversary party to tell us he created the puzzles for DEF CON over the last few years.

Here’s How To Take Part:

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This Hack Chat will take place at noon Pacific time on Friday, August 11th. Don’t know when the Earth’s sun will be directly overhead? Here’s a time and date converter!

Log into Hackaday.io, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Retrotechtacular: The Bell Laboratory Science Series

August 9, 2017 by Dan Maloney 8 Comments

For those of a certain vintage, no better day at school could be had than the days when the teacher decided to take it easy and put on a film. The familiar green-blue Bell+Howell 16mm projector in the center of the classroom, the dimmed lights, the chance to spend an hour doing something other than the normal drudgery — it all contributed to a palpable excitement, no matter what the content on that reel of film.

But the best days of all (at least for me) were when one of the Bell Laboratory Science Series films was queued up. The films may look a bit schlocky to the 21st-century eye, but they were groundbreaking at the time. Produced as TV specials to be aired during the “family hour,” each film is a combination of live-action for the grown-ups and animation for the kiddies that covers a specific scientific topic ranging from solar physics with the series premiere Our Mr. Sun to human psychology in Gateways to the Mind. The series even took a stab at explaining genetics with Thread of Life in 1960, an ambitious effort given that Watson and Crick had only published their model of DNA in 1953 and were still two years shy of their Nobel Prize.

Produced between 1956 and 1964, the series enlisted some really big Hollywood names. Frank Capra, director of Christmas staple It’s a Wonderful Life, helmed the first four films. The series featured exposition by “Dr. Research,” played by Dr. Frank Baxter, an English professor. His sidekick was usually referred to as “Mr. Fiction Writer” and first played by Eddie Albert of Green Acres fame. A list of voice actors and animators for the series reads like a who’s who of the golden age of animation: Daws Butler, Hans Conried, Sterling Halloway, Chuck Jones, Maurice Noble, Bob McKimson, Friz Freleng, and queen and king themselves, June Foray and Mel Blanc. Later films were produced by Warner Brothers and Walt Disney Studios, with Disney starring in the final film. The combined star power really helped propel the films and help Bell Labs deliver their message.

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