We love seeing old technology brought back to life, especially when it’s done in the context of how the device was originally intended to be used. And double points when it’s space gear, like what [Curious Marc] and his usual merry band of cohorts did when they managed to light up a couple of real Apollo DSKY displays.
The “Display and Keyboard” formed the human interface to the Apollo Guidance Computer, the purpose-built machine that allowed Apollo missions to fly to the Moon, land safely, and return to Earth. Complete DSKYs are hard to come by, but a lucky collector named [Marcel] was able to score a pair of the electroluminescent panels, one a prototype and one a flight-qualified spare. He turned them over to AGC guru [Carl Claunch], who worked out all the details of getting the display working again — a non-trivial task with a device that needs 250 volts at 800 Hertz.
The first third of the video below mostly concerns the backstory of the DSKY displays and the historical aspects of the artifacts; skip to around the 12:30 mark to get into the technical details, including the surprising use of relays to drive the segments of the display. It makes sense once you realize that mid-60s transistors weren’t up to the task, and it must have made the Apollo spacecraft a wonderfully clicky place. We were also intrigued by the clever way the total relay count was kept to a minimum, by realizing that not every combination of segments was valid for each seven-segment display.
We always have it on our list to learn more about Orbiter. If you haven’t seen it, it is a hyperrealistic space simulator. Granted, you can put it in an easy mode, but its real strength is you can very accurately model spacecraft like the Space Shuttle and have very realistic controls. In order to spur development, the program is now open source.
We think this is interesting for two reasons. First, if you ever wanted to contribute into a project of this scope, here’s your chance. You might not want to write a full-blow space simulator but you might have something to add. However, open source also means you can see how the program works and either reuse it in your own open source projects or just simply learn from the techniques.
Tell the world that something is in short supply, and you can bet that people will start reacting to that news in the ways that make the most sense to them — remember the toilet paper shortage? It’s the same with the ongoing semiconductor pinch, except that since the item in short supply is (arguably) more valuable than toilet paper, the behavior and the risks people are willing to take around it are even more extreme. Sure, we’ve seen chip hoarding, and a marked rise in counterfeit chips. But we’d imagine that this is the first time we’ve seen chip smuggling quite like this. The smuggler was caught at the Hong Kong-Macao border with 256 Core i7 and i9 processors, valued at about $123,000, strapped to his legs and chest. It reminds us more of “Midnight Express”-style heroin smuggling, although we have to say we love the fact that this guy chose a power of 2 when strapping these babies on.
Speaking of big money, let’s say you’ve pulled off a few chip heists without getting caught, and have retired from the smuggling business. What is one to do with the ill-gotten gains? Apparently, there’s a big boom in artifacts from the early days of console gaming, so you might want to start spreading some money around there. But you’d better prepare to smuggle a lot of chips: last week, an unopened Legend of Zelda cartridge for the NES sold for $870,000 at auction. Not to be outdone, two days later someone actually paid $1.56 million for a Super Mario 64 cartridge, this time apparently still in the tamperproof container that displayed it on a shelf somewhere in 1996. Nostalgia can be an expensive drug.
And it’s not just video games that are commanding high prices these days. If you’ve got a spare quarter million or so, why not bid on this real Apollo Guidance Computer and DSKY? The AGC is a non-flown machine that was installed in LTA-8, the “lunar test article” version of the Landing Module (LM) that was used for vacuum testing. If the photos in the auction listing seem familiar, it’s with good reason: this is the same AGC that was restored to operating condition by Carl Claunch, Mike Stewart, Ken Shiriff, and Marc Verdiell. Sotheby’s estimates the value at $200,000 to $300,000; in a world of billionaire megalomaniacs with dreams of space empires, we wouldn’t be surprised if a working AGC went for much, much more than that.
Meanwhile, current day space exploration is going swimmingly. Just this week NASA got the Hubble Space Telescope back online, which is great news for astronomers. And on Mars, the Ingenuity helicopter just keeps on delivering during its “operations demonstration” mission. Originally just supposed to be a technology demonstration, Ingenuity has proven to be a useful companion to the Perseverance rover, scouting out locations of interest to explore or areas of hazard to avoid. On the helicopter’s recent ninth flight, it scouted a dune field for the team, providing photographs that showed the area would be too dangerous for the rover to cross. The rover’s on-board navigation system isn’t great at seeing sand dunes, so Ingenuity’s images are a real boon to mission planners, not to mention geologists and astrobiologists, who are seeing promising areas of the ancient lakebed to explore.
And finally, most of us know all too well how audio feedback works, and all the occasions to avoid it. But what about video feedback? What happens when you point a camera that a screen displaying the image from the camera? Fractals are what happens, or at least something that looks a lot like fractals. Code Parade has been playing with what he calls “analog fractals”, which are generated just by video feedback and not by computational means. While he’d prefer to do this old school with analog video equipment, it easy enough to replicate on a computer; he even has a web page that lets you arrange a series of virtual monitors on your screen. Point a webcam at the screen, and you’re off on a fractal journey that constantly changes and shifts. Give it a try.
It’s hard to say what exactly it is about the Apollo DSKY that captures so many hackers’ imaginations. Whatever it is, the “Display and Keyboard” unit from the Apollo Guidance Computer has inspired dozens of teardowns, simulations, and reproductions over the years, to varying degrees of success. But this mechanically faithful DSKY replica really knocks it out of the park in terms of attention to detail.
The product of [M. daSilva], this DSKY replica takes a somewhat different path than many of the others we’ve seen. By working from as many original documents as possible, he was able to reproduce the physical size and shape of the DSKY very accurately — no mean feat when working from copies of copies of the original paper prints. Still, the details that are captured, like the gussets and reinforcements that were added to strengthen the original die-cast parts, really make this DSKY look the part. It’s functional, too, thanks to a Raspberry Pi running VirtualAGC, with a Nextion 4.3″ LCD display standing in for the original electroluminescent display. We were surprised to learn the DSKY had a port for nitrogen purging the case; check out the video tour below for that and other tidbits.
Of course, just because [M. daSilva] chose to concentrate on dimensional accuracy for this go-around doesn’t preclude more faithful electronics in the future. Perhaps he can team up with [Ben Krasnow] or [Fran Blanche] and really make this a showpiece.
In this day and age where a megabyte of memory isn’t a big deal, it is hard to recall when you had to conserve every byte of memory. If you are a student of such things, you might enjoy an annotated view of the Apollo 11 DSKY sine and cosine routines. Want to guess how many lines of code that takes? Try 35 for both.
Figuring out how it works takes a little knowledge of how the DSKY works and the number formats involved. Luckily, the site has a feature where you can click on the instructions and see comments and questions from other reviewers.
Imagine you’ve got an Apollo Guidance Computer, the machine that took men to the Moon 50 years ago. You’ve spent ages restoring it, and now it’s the only working AGC on the planet. It’s not as though you’re going to fly to the Moon with it, so what do you do with it? Easy – turn it into a perfectly awful Bitcoin mining rig.
The AGC that [Ken Shirriff] and others have been restoring barely resembles a modern computer. The AGC could only do about 40,000 operations per second, but raw speed was far less important than overall reliability and the abundant IO needed to run a crewed spacecraft. It was a spectacular success on the Apollo missions, but [Ken] wanted to know if turning it into a Bitcoin mining rig was possible.
[Ken] gives a great overview of how Bitcoin mining works, with one of the best explanations of the hashing algorithm we’ve seen. Getting that to run on the AGC was no mean feat, especially with limits imposed by the memory addressing scheme and the lack of machine instructions for manipulating words. He eventually got it working, though, clocking in at a screaming 10.3 seconds per Bitcoin hash. [Ken] estimates that the first coin will be successfully mined in a mere 400 zettaseconds, which is about a billion times older than the universe. With about 13 quadrillion years to the first ka-ching, you have plenty of time to watch a block mined in the video below; alas, it was an old block, so no coins were awarded to compensate the team for their efforts.
It’s been a long time coming but [Fran] finally has a DSKY display, a replica of the user interface display found in the Apollo Guidance Computer. The best part? It’s a t-shirt.
This build is a long, long, time in the making first beginning in 2015 when Fran started investigating the DSKY of the Apollo Guidance Computer. At the time, there were reproductions, but honesty they were all terrible. The reproductions used off-the-shelf seven-segment LEDs or light pipes. The real DSKY was a work of art and at the time probably the most complex electroluminescent display ever created. This led [Fran] to a very special trip to the annex of the Air and Space Museum where she was allowed to inspect a real DSKY display. She got all the measurements, and with some non-destructive investigation, she was able to piece together how this very special display was put together.
With that information, [Fran] was able to figure out that this display was a fairly complex series of silk screens. If it’s silk screen, you can put it on a t-shirt, so that’s exactly what [Fran] did. This used a DIY silk screen jig with phosphorescent inks. It’s not an electroluminescent display, but it does glow in the dark.
While this DSKY t-shirt does glow in the dark, that means it’s not an electroluminescent display like the original DSKY. That said, screen printed electroluminescent displays on a t-shirt aren’t unheard of. Several years ago, a screen printing company did a few experiments with EL displays on wearables. Of course, if you want a real electroluminescent DSKY display, [Ben Krasnow] has a very modern reproduction of the screen printed display. The electronics of [Ben]’s project do not resemble what flew to the moon in any way whatsoever; the original DSKY had relays. That said, we’ve never been closer to a modern recreation of the display from an Apollo Guidance Computer, and we have [Fran] and [Ben]’s work to point us forward.