DSKY – The Apollo Guidance Computer User Interface

Have you ever wondered what it was like to use the computer that the astronauts used when they flew to the moon? I have. I was twelve when Neil Armstrong took his small step, and was already a computer geek. A few years later I managed to get my hands on my "holy grail" - an Apollo Operations Handbook. That's where I learned about the DSKY - the "Display and Keyboard", which was the interface to the onboard computer. The AOH explained - at avery high level - the function and operation of the DSKY.

With typical young programmer's hubris, I figured I now knew enough about the basics of how the DSKY worked that I could cobble something together that would be a reasonable approximation. But, lacking the appropriate image handling toolkits (Macintosh and Windows were far in the future), the idea languished...

Virtual AGC

And then one day (many years later) I found Ron Burkey's Virtual AGC project, and I was blown away! This wasn't just an "approximation" – this was as close to the real thing as any mere mortal could hope to get. The only problem ... it didn't run on my Palm Tungsten PDA, so I couldn't have it with me at all times. :-)

Then my Palm was succeeded by an iPod Touch, and I found Jonathan Stark's Building iPhone Apps with HTML, CSS and JavaScript, and since I knew HTML, and CSS, and JavaScript, this seemed like the perfect answer: a development environment that didn't require a big investment in time or money or learning curve!


So naturally, my DSKY simulation was the first thing I wanted to try. Serendipitously, Frank O'Brien's The Apollo Guidance Computer: Architecture and Operation was published at just the same time I started coding. I'd thought that Ron Burkey's site would provide me with everything I could possibly want to know to simulate the AGC/DSKY, but O'Brien's book really did provide new – and useful – information.

It didn't take long to have a working skeleton; but actually having something that really worked like the DSKY took fair bit longer. It currently does everything on the Virtual AGC page listed under Playing with Colossus and Playing with Luminary.) But frankly, that still wasn't very satisfying, since it didn't really do anything functional. I decided to at least get it to do what the real thing would do until the point of getting into earth orbit. Eventually


emerged. It faithfully implements the most of the basic operation, but only a minimal subset of the functionality of the AGC/DSKY. It's specifically targeted at the iPhone and iPod Touch, but it works reasonably well on most any reasonably-current JavaScript-capable web browser.

Going Further

I apologize for having had most of the fun. Writing iDSKY has vastly increased my knowledge of the AGC and how it works (fun); as a programmer, rising to the challenge of making a faithful simulation was ... more fun. But you can peruse the Javascript source code, and maybe even make it do more than it does now. If iDSKY piques your interest, you can delve into Virtual AGC, and maybe even get a copy of O'Brien's book. If iDSKY gets you hooked on learning more about the AGC, then I'll feel better about sharing the fun. Enjoy!

Installing as an App on iOS