Home | Writings | Resume | Links | RSS Feed
A Proud Member of the Reality-Based Community
About Me :
I'm a grownup nerd living in the Boston burbs. I write computer programs for a living and plays for fun.
I'm married to a wonderful woman, and we share a nice little house with our daughter and our cats.
I'm a humanist, a technologist, an artist, and an idealist. I believe in reason, freedom, love, equality,
and democracy. (Did I mention that I'm
an idealist? I did, OK.)
I'm also a pragmatist and an empiricist. I reject ideology and dogma, especially when they conflict with
practical facts (i.e., pretty much always). I particularly hate willful ignorance, which tends to go hand-in-hand
with ideology and dogma.
Like the alignment of the planets, this blog gets updated as I have the time, inspiration, and inclination to do so.
Like the alignment of the planets, this blog gets updated as I have the time, inspiration, and inclination to do so.
Thursday, February 10, 2005
Now All He Needs Is A Space Ship
John Pultorak is my kind of nerd. This guy has built a replica of the Apollo Guidance Computer, the computer that flew on the Command Module and Lunar Module of the Apollo manned missions to the moon in the 1960s and 1970s.
Pultorak built the replica over the course of four years of nights and weekends, with some assistance from his son and a lot of understanding patience from his wife.
Recreating a 40-year-old computer is not an easy task, even if the hardware isn't exactly cutting-edge. Pultorak didn't just simulate the AGC (although that's what he did as a first step). He didn't even just emulate the AGC (i.e. build a modern computer and program it to pretend to be the AGC). He built real hardware which works just like the original. He didn't replicate the original in all respects, because he discovered that some of the parts which were used to build the original AGC weren't available any more. (Just try to find core rope memory these days.)
The AGC was definitely cutting-edge for its time (roughly 1962). It was the first digital computer to replace discrete transistors with Integrated Circuits, which were new and risky. It also was the first digital autopilot for any kind of piloted vehicle, and its user interface (the Display and Keyboard Unit or DSKY) was far ahead of its time, even if it seems a little quaint to us, and is one of the earliest examples of a real-time interactive user interface. In the 60s, after all, most computer users interacted with the machine via punch cards and printouts.
Others have implemented simulations of the AGC/DSKY. The Virtual AGC Project is one such effort, and the NASSP Project has implemented a DSKY in their Orbiter add-on (See this image). A more accessible, but less complete, partial implementation of a DSKY can be found here. I recommend it to anyone who is curious but doesn't want to be overwhelmed. It's a nice introduction, but it only works in Internet Explorer.
All of these efforts to replicate the space flight experience inside our modern computers are commendable, but for sheer geeky bragging rights, nothing really beats being able to say, as Pultorak can, "I built the real thing myself."
0 comments
John Pultorak is my kind of nerd. This guy has built a replica of the Apollo Guidance Computer, the computer that flew on the Command Module and Lunar Module of the Apollo manned missions to the moon in the 1960s and 1970s.
Pultorak built the replica over the course of four years of nights and weekends, with some assistance from his son and a lot of understanding patience from his wife.
Recreating a 40-year-old computer is not an easy task, even if the hardware isn't exactly cutting-edge. Pultorak didn't just simulate the AGC (although that's what he did as a first step). He didn't even just emulate the AGC (i.e. build a modern computer and program it to pretend to be the AGC). He built real hardware which works just like the original. He didn't replicate the original in all respects, because he discovered that some of the parts which were used to build the original AGC weren't available any more. (Just try to find core rope memory these days.)
The AGC was definitely cutting-edge for its time (roughly 1962). It was the first digital computer to replace discrete transistors with Integrated Circuits, which were new and risky. It also was the first digital autopilot for any kind of piloted vehicle, and its user interface (the Display and Keyboard Unit or DSKY) was far ahead of its time, even if it seems a little quaint to us, and is one of the earliest examples of a real-time interactive user interface. In the 60s, after all, most computer users interacted with the machine via punch cards and printouts.
Others have implemented simulations of the AGC/DSKY. The Virtual AGC Project is one such effort, and the NASSP Project has implemented a DSKY in their Orbiter add-on (See this image). A more accessible, but less complete, partial implementation of a DSKY can be found here. I recommend it to anyone who is curious but doesn't want to be overwhelmed. It's a nice introduction, but it only works in Internet Explorer.
All of these efforts to replicate the space flight experience inside our modern computers are commendable, but for sheer geeky bragging rights, nothing really beats being able to say, as Pultorak can, "I built the real thing myself."
