An Apollo Guidance Computer Laid Bare

An Apollo Guidance Computer probably isn’t a machine that’s likely to come the way of most Hackaday readers. The device that played such a vital role in taking astronauts to the Moon and bringing them home again is hardly a common find, even if it is one of the most iconic machines of its type and era.

[Carl Claunch] was approached to assist in the restoration of an AGC, and while he can’t reveal any information about its owner he is at liberty to document his progress. The result is a fascinating in-depth technical examination of the device over multiple blog posts, and is well worth a read for anyone with an interest in the Apollo program. It’s an ongoing progression of blog posts that are probably too numerous to list individually, but include the construction of a substitute for the DSKY control panel as well as looking at the device’s memory and construction. [Carl] then embarks on a series of posts looking at the restoration itself. This is where we see the computer in greatest detail, and learn the most about it.

If you think you might have seen [Carl]’s name here before, you’d be right. One of his past exploits was getting the first version of FORTH running on an IBM mainframe.

Margaret Hamilton Takes Software Engineering To the Moon and Beyond

If you were to create a short list of women who influenced software engineering, one of the first picks would be Margaret Hamilton. The Apollo 11 source code lists her title as “PROGRAMMING LEADER”. Today that title would probably be something along the line of “Lead software engineer”

Margaret Hamilton was born in rural Indiana in 1936. Her father was a philosopher and poet, who, along with grandfather, encouraged her love of math and sciences. She studied mathematics with a minor in philosophy, earning her BA from Earlham College in 1956. While at Earlham, her plan to continue on to grad school was delayed as she supported her husband working on his own degree from Harvard. Margaret took a job at MIT, working under Professor Edward Norton Lorenz on a computer program to predict the weather. Margaret cut her teeth on the desk-sized LGP-30 computer in Norton’s office.

Hamilton soon moved on to the SAGE program, writing software which would monitor radar data for incoming Russian bombers. Her work on SAGE put Margaret in the perfect position to jump to the new Apollo navigation software team.

The Apollo guidance computer software team was designed at MIT, with manufacturing done at Raytheon. To say this was a huge software project for the time would be an understatement. By 1968, over 350 engineers were working on software. 1400 man-years of software engineering were logged before Apollo 11 touched down on the lunar surface, and the project was lead by Margaret Hamilton.
Continue reading “Margaret Hamilton Takes Software Engineering To the Moon and Beyond”

Hackaday Links: February 18, 2018

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

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.

Continue reading “Start Your Apollo Collection with an Open Source DSKY”

34C3: Ultimate Apollo Guidance Computer Talk

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.

The Longest Tech Support Call: Apollo 14 Computer Hack

Deep-voiced and aptly named [Scott Manley] posted a video about the computer hack that saved Apollo 14. Unlike some articles about the incident, [Scott] gets into the technical details in an entertaining way. If you don’t remember, Apollo 14 had an issue where the abort command button would occasionally signal when it shouldn’t.

The common story is that a NASA engineer found a way to reprogram the Apollo guidance computer. However, [Scott] points out that the rope memory in the computer wasn’t reprogrammable and there was no remote way to send commands to the computer anyway.

Continue reading “The Longest Tech Support Call: Apollo 14 Computer Hack”

Hackaday Links: August 20, 2017

Foam core, dollar tree foam board, Adams foam board, or whatever we’re calling a thin sheet of foam sandwiched between two pieces of poster board, is an invaluable hacker’s tool. Everyone should have a few sheets on hand, and not just because each sheet is a dollar each at any Dollar Store. [Eric] has been working on a technique to create compound curves in foam board, and the results look great. It’s a true three-dimensional plane with weird curves, and certainly has applications for something.

The Apollo Lunar Module is the first, and only manned space-only spacecraft ever made. The design of this spacecraft isn’t constrained by trivialities like ‘atmosphere’, and the design didn’t need ‘bulkheads thicker than a stack of paper towels’. It is a beautiful ship, and now a company wants to produce a gorgeous 1/32 scale model of the LEM. The goal is $25k, which is quite high for the real space modeling market, but if this GoFundMe campaign succeeds, this will be one of the finest real space models ever created. It’ll also match the scale of the 1/32 Revell CSM.

Speaking of Apollo-related technology, here’s a slight bit of drama. [Fran] has been working on recreating the DSKY — the user interface for the Apollo Guidance Computer — for a few years now. She’s set up a crowdfunding campaign to recreate the electroluminescent, screen printed segment display, and things are going great. Now there’s a company selling commercial DSKYs (with a stupid TFT display), that potentially uses the same art. Is this copyright infringement? Maybe, but probably not. It is a dick move not to credit [Fran], though.

The Monoprice Mini Delta is phenomenal. More on that in a bit.

There’s a complete solar eclipse happening across the United States tomorrow. Many schools should have started classes by then, but they’re calling tomorrow a snow day. Everyone who is traveling to see the eclipse is probably already where they’re going to be, and there are clouds on the horizon. Literal clouds. Everyone is watching the weather channel to see what the cloud cover will be tomorrow. Some people don’t have to worry: [Dan] is building a high-altitude balloon to get 100,000 feet above any clouds. There’s a 360° camera onboard, and the resulting video will be awesome. At least one person in Charleston will be renting a plane; I question the wisdom of renting a 172 over a Piper or Cirrus or another low-wing plane, but whatever. If you’re working on a project that will look at the eclipse from above the clouds, leave a note in the comments. For those of you looking at clouds tomorrow, Hackaday is doing another eclipse meet up on the Pacific coast of Mexico on April 8, 2024.