[Ben Krasnow] Makes A DSKY

May 19, 2019 by Dan Maloney 6 Comments

There are hundreds if not thousands of artifacts from the Apollo program scattered around the globe, some twisted wrecks at the bottom of the ocean, others lovingly preserved and sitting in museums or in the hands of private collectors. All of what’s left is pretty much pure unobtainium, so if you want something Apollo-like, you’re probably going to have to make it yourself.

[Ben Krasnow] took up the challenge to make an electroluminescent Apollo-era DSKY display from scratch, with outstanding results. The DSKY, or “display and keyboard”, was the user interface for the Apollo Guidance Computer, the purpose-built digital navigation system that got a total of 24 men there and back again. [Ben] says it took a long time to recreate the display, and we can see why. He needed to master quite a few skills, including screen printing to get the glass-panel display working. The panel is a sandwich of phosphorescent paint, a dielectric, and conductive ink. The ink is silkscreened on the back to form the characters, all applied to indium tin oxide (ITO) conductive glass. A PCB with the same pattern of character segments lays behind that, driving each segment with 300 volts or so through a trio of HV507 high-voltage shift registers. It’s an impressive bit of engineering and gives off a decidedly not-homebrew vibe.

In the video below, [Ben] goes into detail about the trials he experienced on the way to this amazing endpoint, not least of which was frying chip after chip due to ineffective protection diodes in the shift registers. That’s an epic debugging story that’s worth the price of admission all by itself. It’s not the only DSKY in town, of course – [Fran Blanche] has been working on one for a while too – but there’s just something about that blue glow that we really like.

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Rolling Old School With Copy Protection From The 1980s

May 27, 2018 by Dan Maloney 47 Comments

Oh, for the old days when sailing the seas of piracy was as simple as hooking a couple of VCRs together with a dubbing cable. Sure, the video quality degraded with each generation, but it was so bad to start out with that not paying $25 for a copy of “Ghostbusters” was a value proposition. But then came The Man with all his “rules” and “laws” about not stealing, and suddenly tapes weren’t so easy to copy.

If you’ve ever wondered how copy protection worked in pre-digital media, wonder no more. [Technology Connections] has done a nice primer on one of the main copy protection scheme from the VHS days. It was dubbed “Analog Protection System” or “Analog Copy Protection” by Macrovision, the company that developed it. Ironically, Macrovision the company later morphed into the TiVo Corporation.

The idea for Macrovision copy protection was to leverage the difference between what a TV would accept as a valid analog signal and what the VCR could handle. It used the vertical blanking interval (VBI) in the analog signal, the time during which the electron beam returns to the top of the frame. Normally the VBI has signals that the VCR uses to set its recording levels, but Macrovision figured out that sending extra signals in the VBI fooled the VCR’s automatic gain controls into varying the brightness of the recorded scenes. They also messed with the vertical synchronization, and the effect was to make dubbed tapes unwatchable, even by 1985 standards.

Copy protection was pretty effective, and pretty clever given the constraints. With Digital Rights Management, it’s easier to put limits on almost anything — coffee makers, arcade games, and even kitty litter all sport copy protection these days. It almost makes us nostalgic for the 80s.

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Hackaday Links: February 18, 2018

February 18, 2018 by Brian Benchoff 50 Comments

Hacker uses pineapple on unencrypted WiFi. The results are shocking! Film at 11.

Right on, we’ve got some 3D printing cons coming up. The first is MRRF, the Midwest RepRap Festival. It’s in Goshen, Indiana, March 23-25th. It’s a hoot. Just check out all the coverage we’ve done from MRRF over the years. Go to MRRF.

We got news this was going to happen last year, and now we finally have dates and a location. The East Coast RepRap Fest is happening June 22-24th in Bel Air, Maryland. What’s the East Coast RepRap Fest? Nobody knows; this is the first time it’s happening, and it’s not being produced by SeeMeCNC, the guys behind MRRF. There’s going to be a 3D printed Pinewood Derby, though, so that’s cool.

జ్ఞ‌ా. What the hell, Apple?

Defcon’s going to China. The CFP is open, and we have dates: May 11-13th in Beijing. Among the things that may be said: “Hello Chinese customs official. What is the purpose for my visit? Why, I’m here for a hacker convention. I’m a hacker.”

Intel hit with lawsuits over security flaws. Reuters reports Intel shareholders and customers had filed 32 class action lawsuits against the company because of Spectre and Meltdown bugs. Are we surprised by this? No, but here’s what’s interesting: the patches for Spectre and Meltdown cause a noticeable and quantifiable slowdown on systems. Electricity costs money, and companies (server farms, etc) can therefore put a precise dollar amount on what the Spectre and Meltdown patches cost them. Two of the lawsuits allege Intel and its officers violated securities laws by making statements or products that were false. There’s also the issue of Intel CEO Brian Krzanich selling shares after he knew about Meltdown, but before the details were made public. Luckily for Krzanich, the rule of law does not apply to the wealthy.

What does the Apollo Guidance Computer look like? If you think it has a bunch of glowey numbers and buttons, you’re wrong; that’s the DSKY — the user I/O device. The real AGC is basically just two 19″ racks. Still, the DSKY is very cool and a while back, we posted something about a DIY DSKY. Sure, it’s just 7-segment LEDs, but whatever. Now this project is a Kickstarter campaign. Seventy bucks gives you the STLs for the 3D printed parts, BOM, and a PCB. $250 is the base for the barebones kit.

Start Your Apollo Collection With An Open Source DSKY

February 2, 2018 by Dan Maloney 20 Comments

Given that there have been only six manned moon landings, and that almost all of the hardware that started on the launch pad was discarded along the way, getting your hands on flown hardware is not generally the business of mere mortals. Such artifacts are mostly in museums or in the hands of very rich private collectors. Enthusiasts have to settle for replicas like this open source Apollo Guidance Computer DSKY.

The DSKY, or Display and Keyboard, was the user interface for the Apollo Guidance Computer, that marvel of 1960s computer engineering that was purpose-built to control the guidance and navigation of the Command and Lunar Excursion modules. [ST-Geotronics] has made a decent replica of the DSKY using 3D-printed parts for the housing and bezel. There’s a custom PCB inside that houses a matrix of Neopixels for the indicator light panel and seven-segment LEDs for the numeric displays. Sadly but understandably, the original electroluminescent display could not be reproduced, but luckily [Fran Blanche] is working on just that project these days. The three-segment displays for the plus and minus signs in the numeric displays proved impossible to source commercially, so the team had to roll their own for that authentic look. With laser cut and engraved overlays for the displays and keycaps, the look is very realistic, and the software even implements a few AGC-like functions.

We like this a lot, although we could do without the sound clips, inspirational though Kennedy’s speech was. Everything is open source so you can roll your own, or you can buy parts or even a complete kit too.

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34C3: Ultimate Apollo Guidance Computer Talk

December 28, 2017 by Tom Nardi 14 Comments

While it might not be as exciting as the Saturn V rocket itself, the Apollo Guidance Computer (AGC) was one of the most important developments of the entire Apollo program. While comically underwhelming compared to modern hardware, the AGC was nothing short of revolutionary when it was developed in the 1960’s. Before the AGC, the smallest computers were about the size of a refrigerator and consumed hundreds of watts; both big problems if you’re trying to pack them into a relatively tiny space capsule with limited resources. Not only did the AGC get humanity to the Moon and back, but it also redefined the state of the art for microcomputers, paving the way for the desktop systems of the 1970’s.

That said, the design and operation of the AGC is downright bizarre to modern eyes; it comes from a time of limitations we can hardly fathom. With this in mind, [Michael Steil] and [Christian Hessmann] put together “The Ultimate Apollo Guidance Computer Talk” for 34C3.

This hour-long presentation walks viewers through every aspect of not only the AGC itself, but how it interacted with the Saturn V rocket and the overall lunar mission. Even if you aren’t enough of a vintage computing aficionado to appreciate the complexities of core rope memory, the presentation gives a fascinating look at the gritty details of one of humanity’s greatest achievements.

Though very slick and easy to understand graphics, [Michael] and [Christian] break down the alien world of the AGC. Even if a lot of this part of the presentation goes over your head, just listen for the sounds of laughter or applause from the audience: that’s when you’re looking at something really off-the-wall.

Of particular note during this presentation is the explanation of how the astronauts actually interacted with the AGC. The AGC’s display and keyboard (referred to as DSKY) may seem rather obtuse even to those who used to hack on a VT100, but [Michael] and [Christian] explain how it’s not quite as complex as it seems. Comparing the input and output of the DSKY with what we would see on a more contemporary command line interface, the presentation makes the case that it’s actually a very straightforward way of talking to the computer.

There’s also a complete breakdown of the different phases of the Apollo mission from launch to landing, explaining what the AGC would be doing at any given time. The DSKY is overlaid on actual footage from the Apollo missions, giving a unique perspective as to what the astronauts would see on their computer during iconic moments such as stage separation or lunar touchdown.

If this presentation has you hungry for more Apollo-era computer technology, we’ve covered plenty of projects to keep you occupied. From building a replica DSKY to leisurely paging through the printed version of the AGC’s source code.

Decoding Rediscovered Rope Memory From The Apollo Guidance Computer

September 2, 2016 by Brian Benchoff 43 Comments

On August 25th, 1966, an Apollo Command Module was launched aboard a Saturn IB rocket in mission AS-202. This mission was intended to immediately precede the ill-fated Apollo 1 mission, the AS-202 was unmanned, serving as a test of flight hardware, fuel cells, and the guidance and navigation control systems. This mission used the first Apollo Guidance Computer ever flown, and this mission was vital to testing the computer that would take men to the moon.

While the software from the later missions exists and is available on Github, the earlier Block I spacecraft, including the unmanned Apollo 4 and Apollo 6 missions, are poorly documented. [Francois Rautenbach] was lucky enough to get his hands on the rope memory modules from the AS-202 mission. Now he’s investigating these modules with oscilloscopes and x-rays to recreate some of the first software that was flown in space.

The procedure to extract the data from these rope memory modules is a bit harder than reading a bit of Flash off a chip. Rope memory is weird, but with a contraption made out of a lot of relays and an oscilloscope, [Francois] was able to capture data from these memory modules.

Of course, [Francois] first needed to figure out the pinout for the gigantic backplane connector on each of these memory modules. To do that, he checked out a Block II AGC, read the schematics very carefully, and reverse engineered a connector that isn’t made anymore. The next step was x-raying the rope memory modules to see how they were assembled. Even though these memory modules contain the only extant copy of the Block I AGC software, even reading one bit off of these modules is an amazing case of technological archeology.

The answer to the obvious question — where did these modules come from — is exactly what you would expect. These memory modules were picked up off a scrap heap forty years ago. The gentleman who found these modules was kind enough to give them to [Francois]. Check out the videos below for [Francois]’ video logs. If you’re into slightly more destructive testing of forgotten Apollo flight hardware, [Fran Blanche] tore down a few modules from the Apollo Launch Vehicle Digital Computer a few years ago.

Thanks to [Vincent], [Danie], and [Kent] for jumping on this one and sending it into the tip line.
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[Fran]’s New Project: The DSKY

November 28, 2014 by Brian Benchoff 29 Comments

[Fran] has already made a name for herself in some retro cool historical aviation and computer circles by tearing down a flight-ready spare of a Saturn V launch vehicle digital computer, the computer that was responsible for getting all flights to the moon into low earth orbit. Now she’s ready for another project, and again, this is something that hasn’t been done in 40 years. She’s building a DSKY, the control panel for the Apollo Guidance Computer

The Apollo Guidance Computer is a well-documented piece of computing history, with homebrew versions all over the web. The DSKY is only one small part of the AGC, but it is by far the most famous module. Being the only user interface for the AGC, it’s the only part of the AGC that gets all the screen time in Apollo 13, the travesty on BluRay that was Apollo 18, and is the only device that bears any physical resemblance to its real-life counterpart in a number of AGC simulators.

That’s not to say DSKY builds haven’t been attempted before; there are a few out there using LEDs and off-the-shelf buttons for the build, but the DSKY from the mid-60s is much, much cooler than a bunch of LEDs and light pipes. The eery green numbers are actually EL displays. Guess how those displays are controlled? Relays. It’s a masterpiece of technology, made even more impressive in that the folks at MIT who built the thing didn’t have anything better to build the display with.

Because of her deconstruction efforts with the Saturn V LVDC, [Fran] was invited down to the National Air and Space museum in the middle of Washington DC. There, she saw everyones favorite ugliest spacecraft, the Apollo LEM, along with an incredible assortment of paraphernalia from aviation history. The Wright Flyer – yes, the original one – is hanging from the ceiling next to the Spirit of St. Louis, and X-15 rocket plane, right above the command module Columbia from Apollo 11. Copies of probes currently rolling over Mars are on display, and you can walk through a training model of Skylab. If you’ve never been, spend half a day there, then take the metro out to the Udvar-Hazy center, where you’ll find all the stuff they couldn’t fit in the downtown collection like a Space Shuttle and a Concorde.

This is only the first part of [Fran]’s vlog documenting the construction of a copy of the DSKY, and we haven’t even seen the inner guts of the most famous part of the AGC yet. She’s been working on this for a while now, and there’s no doubt she’ll finish the job and come up with the best replica of a DSKY ever.