Hackaday Links: August 14, 2016

Hey London peeps! Hackaday and Tindie are doing a London meetup! It’s this Wednesday, the 17th.

What do you do if you need Gigabytes of storages in the 80s? You get tape drives. What do you do if you need Terabytes of storage in the year 2000? You get tape. The IBM Totalstorage 3584 is an automated tape storage unit made sometime around the year 2000. It held Terabytes of data, and [Stephen] picked up two of them from a local university. Here’s the teardown. Unfortunately, there’s no footage from a GoPro stuck inside the machine when it’s changing tapes, but the teardown was respectable, netting two drives, the power supplies, and huge motors, fans, relays, and breakers.

A few years ago Motorola released the Lapdock, a CPU-less laptop with inputs for HDMI and USB. This was, and still is, a great idea – we’re all carrying powerful computers in our pocket, and carrying around a smartphone and a laptop is effort duplication. As you would expect, the best use for the Lapdock was with a Raspberry Pi, and prices of Lapdocks have gone through the roof in the last few years. The Superbook is the latest evolution of this Lapdock idea. It’s a small, thin, CPU-less laptop that connects to a phone using a special app and a USB cable. It also works with the Raspberry Pi. Very interesting, even if they didn’t swap the CTRL and Caps Lock keys as God intended.

Did you know we have a store? Yes! It’s true! Right now we need to get rid of some stuff, so we’re having a clearance sale. We got FPGA Arduino shields! Buy a cordwood puzzle! SUPERLIMINAL ADVERTISING.

The computers aboard Federation vessels in the 24th century were based on isolinear chips. Each chip plugged into a backplane, apparently giving certain sections of the ship different functions. Think of it as a reconfigurable PDP Straight-8. This is canon, from TNG, and doesn’t make any sense. [Bohrdasaplank] over on Thingiverse has a few different models of isolinear chips. After close examination of these chips, we can only come to one conclusion.

How do you get a pilot bearing out of a motor? The normal way is using grease (or caulk, or some other gooey substance) as a hydraulic ram, but a slice of bread works much better. This is a weird one, but it works perfectly, with hardly any cleanup whatsoever.

542-page PDF warning here. Here’s the operations manual for the Apollo 15, including operation of the AGC, how to fly the LM, the planned traverses and EVAs, and a nice glossary of handy equations. If anyone’s looking for a LaTeX, InDesign, or bookbinding project that would make the perfect bathroom reader, this is it.

Here’s something I’ve been having trouble with. This is an mATX computer case with a screen on the side and a cover for the screen that includes a keyboard and trackpad. Yes, it’s a modern version of the luggable, ‘portable’, plasma-screen monsters of the 80s. I don’t know where I can buy just the case, so I’m turning to the Hackaday community. There’s an entire line of modern luggable computers made by some factory in Taiwan, but as far as I can tell, they only sell to resellers who put their own mobo and CPU in the machine. I just want the case. Where can I buy something like this? If you’re asking why anyone would want something like this, you can put two 1080s in SLI and still have a reasonably portable computer. That’s a VR machine, right there.

Riding Shotgun In The Apollo 12 Lunar Lander

Last week we had a walk through of the Lunar Module’s source code with Don Eyles, who wrote the landing programs. Now you can take a rather thrilling ride to see Don’s code in action.

Below is an annotated video of the Apollo 12 landing, in real-time. It’s worth setting aside a quarter-hour to check it out. In an age where everyone is carrying around an HD (or way better) camera in their pocket, following along with radio broadcasts, still images, and small slivers of video might not sound that awesome. But it is!

p63-apollo-12-codeThe video takes us from Powered Descent Initiation through touchdown on the Moon with Pete Conrad and Alan Bean. As the audio plays out the video has annotations which explain what is going on and that translate the jargon used by the team. With the recently celebrated push to publish the source code you can even follow along as the video displays which program is running at that time. Just search for the program code and you’ll find it, like this screenshot of the P63 routine. The code comments are more than enough to get the gist of it all.

If you enjoy this, the description of the YouTube video below includes links to similar videos for Apollo 11, 14, 15, 16, and 17.

[Thanks to Paul Becker for sending along this video]

Don Eyles Walks Us Through the Lunar Module Source Code

A couple weeks ago I was at a party where out of the corner of my eye I noticed what looked like a giant phone book sitting open on a table. It was printed with perforated green and white paper bound in a binder who’s cover looked a little worse for the wear. I had closer look with my friend James Kinsey. What we read was astonishing; Program 63, 64, 65, lunar descent and landing. Error codes 1201, 1202. Comments printed in the code, code segments hastily circled with pen. Was this what we thought we were looking at? And who brings this to a party?

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Cover Your Glass: A Lesson in Design Trades

Penn and Teller once had a show about “What is the best?” Engineers know that’s not a complete question. Think about a car. What makes the “best” car? It depends on why you want a car. For a race car driver, it might be that speed is the most important factor. A mom might value safety. Someone who commutes four hours a day might like a car that’s comfortable. A teenager wants something affordable.

If you think about it, though, it is even more complicated than that. For example, just about everyone wants a car that is safe. Reliability is pretty important, too. So the reality is, most people want a car that has multiple attributes. Worse still, they sometimes conflict; making one better will make some other ones worse. Mom wants a safe car, but not one that takes half a day to drive to the corner market. Nor does she want to pay a half million dollars for a safe car.

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The Price of Space

Many engineers of a certain age have one thing in common: Their early interest in science and engineering came from watching the US and Russian space programs. To me, regardless of any other benefit from the space program (and there are many), that ability to inspire a future generation of engineers made the entire program worthwhile.

We live in a world where kids’ role models are more likely to be sports or entertainment figures that have regular visits to police stations, jails, and rehab centers. The value of having role models that “do science” is invaluable.

This time of the year is a dark time for NASA missions, though. On January 27, 1967, the Apollo I crew (Grissom, White, and Chaffee) died in a fire. The investigation led to NASA limiting how much Velcro you can use in a cabin and moving away from pure oxygen in the cabin.

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Hanging Out With Someone Who Walked On The Moon

Lunar dune buggy rides, piloting the most powerful machine made by humankind, stuck thrusters, landing, eating, sleeping, and working on the moon. It does not get any more exciting than the Apollo program! I was recently given the opportunity to sit in on the MIT course, Engineering Apollo: the Moon Project as a Complex System where I met David Scott who landed on the moon as commander of Apollo 15. I not only sat in on a long Q and A session I also was able to spend time with David after class. It is not every day you that you meet someone who has landed on the moon, below are my notes from this experience.

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Reproducing A DSKY

This is a project that is about a year and a half in the making, but [Fran] is finally digging into the most iconic part of the Apollo Guidance Computer and building the most accurate reproduction DSKY ever.

The Apollo Guidance Computer was a masterpiece of engineering and is frequently cited as the beginning of the computer revolution, but it didn’t really look that interesting – it looks like a vastly overbuilt server blade, really. When everyone thinks about the Apollo Guidance Computer, they think about the DSKY, the glowey keypad interface seen in the blockbuster hit Apollo 13 and the oddly accurate disappointment of Apollo 18. It’s the part of the Apollo Guidance Computer the Apollo astronauts actually interacted with, and has become the icon of the strange, early digital computers developed for NASA in the 60s.

There are a few modern DSKY replicas, but all of them are exceedingly anachronistic; all of these reproductions use seven-segment LEDs, something that didn’t exist in the 1960s. A true reproduction DSKY would use custom electroluminescent displays. These EL segments are powered by AC, and transistors back then were terrible, leading to another design choice – those EL segments were turned on and off by relays. It’s all completely crazy, and aerospace equipment to boot.

Because of the custom design and engineering choices that seem insane to the modern eye, there isn’t much in the way of documentation when it comes to making a reproduction DSKY. This is where [Fran] tapped a few of the contacts her historical deconstruction cred earned when she reverse engineered a Saturn V Launch Vehicle Digital Computer to call upon anyone who would have access to a real Apollo-era DSKY.

The first contact was the Kansas Cosmosphere who was kind enough to send extremely detailed photographs of the DSKYs in their archives. It would have been extremely nice to have old documentation made when the DSKYs were rolling off the assembly line, but that information is locked away in a file cabinet owned by Raytheon.

[Fran] got a break when she was contacted by curators at the National Air and Space Museum’s Garber facility who invited her down to DC. She was given the grand tour, including the most elusive aircraft in the museum’s collection, the Ho 229, the dual-turbojet Nazi flying wing. At the Garber facility, [Fran] received permission to take apart two DSKYs.

The main focus of [Fran]’s expedition to the Air and Space Museum was to figure out how the EL displays were constructed. The EL displays that exist today are completely transparent when turned off because of the development of transparent conductors.

The EL displays in the DSKY were based on earlier night lights manufactured by Sylvania. After looking at a few interesting items that included Gemini hardware and early DSKYs, this sort of construction was confirmed.

With a lot of pictures, a lot of measurements, a lot of CAD work, and some extremely tedious work, [Fran] was able to create the definitive reference for DSKY display elements. There are 154 separate switchable element in the display, all controlled by relays. These elements are not multiplexed; every element can be turned on and off individually.

Figuring out how the elements were put together was only one part of [Fran]’s research. Another goal was to figure out the electrical connections between the display and the rest of the DSKY. There, [Fran] found 160 gold pins in a custom socket. It’s bizarre, and more like a PGA socket than like the backplane connector [Fran] found in the Saturn V computer.

Even though [Fran]’s research was mostly on the EL panel inside the display, she did get a few more insights with her time with the DSKYs. The buttons are fantastic, and the best keys she’d ever used. This is just part one of what will be an incredibly involved project, and we’re looking forward to what [Fran] looks into next.