EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: VK3DRB on September 09, 2015, 02:08:02 pm
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Every bit of this documentary is fascinating.
They look like 7 segment LED's... from the mid 1960's? Impossible. Were they VFD's? They did not look like it. I am a bit stumped on that.
The testing is very impressive, as is the calibre of these engineers.
Enjoy!
https://www.youtube.com/watch?v=YIBhPsyYCiM (https://www.youtube.com/watch?v=YIBhPsyYCiM)
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That is simply amazing, what a tedious procedure. Those poor people winding those modules, probably still cross eyed, :scared:
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They look like 7 segment LED's... from the mid 1960's? Impossible. Were they VFD's? They did not look like it. I am a bit stumped on that.
Electroluminescent. https://en.wikipedia.org/wiki/Apollo_Guidance_Computer#DSKY_interface
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The 'verb' and 'noun' is also pretty clever given the human interaction possibilities of the computer. It still means the operator needs to learn all of them (maybe from a couple of hundred up to several 1000).
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Looking at the people in the video I got the distinct impression of the late 40ies or 50ies. Definitely not the end of late 60ies...
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Here are the schematics:
http://klabs.org/history/ech/agc_schematics/ (http://klabs.org/history/ech/agc_schematics/)
And a guy who built one in his basement:
http://klabs.org/history/build_agc/ (http://klabs.org/history/build_agc/)
Or you can run a simulator:
http://www.ibiblio.org/apollo/ (http://www.ibiblio.org/apollo/)
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The 'verb' and 'noun' is also pretty clever given the human interaction possibilities of the computer. It still means the operator needs to learn all of them (maybe from a couple of hundred up to several 1000).
Yeah, quite elegant. It made great use of limited memory/display space. The Space Shuttle used a very similar interface. http://history.nasa.gov/computers/Ch4-6.html (http://history.nasa.gov/computers/Ch4-6.html)
Great little documentary.
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Fran Blanche is trying to build an authentic replica of the DSKY display:
https://www.youtube.com/watch?v=UjcfepTdvZI (https://www.youtube.com/watch?v=UjcfepTdvZI)
https://www.youtube.com/watch?v=cEa2CPPIQEM (https://www.youtube.com/watch?v=cEa2CPPIQEM)
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I will have to watch that first video. I don't remember seeing it.
Much Coolness hides inside those old electronics. :)
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Looking at all that damned spaghetti, it's a miracle we made it to the moon at all. For an interesting read on the MIT IL and the Apollo guidance computer, check out:
http://www.amazon.com/Digital-Apollo-Human-Machine-Spaceflight/dp/0262516101/ref=sr_1_1?ie=UTF8&qid=1441857808&sr=8-1&keywords=Digital+Apollo (http://www.amazon.com/Digital-Apollo-Human-Machine-Spaceflight/dp/0262516101/ref=sr_1_1?ie=UTF8&qid=1441857808&sr=8-1&keywords=Digital+Apollo)
It's an odd perspective because they really regarded having humans in the loop as quite a nuisance.
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These people who developed the computer are in my opinion heroes of mankind who deserve accolades and whose names should be enshrined. Instead, most people have never heard of these great pioneers of technology but they all know about celebrities like that twerp Bieber and barge-arse Kim who have produced nothing of value to humanity.
Apollo Guidance Computer (AGC)
Dimensions: 24 x 12.5 x 6.5 inches
Weight: 70 pounds
Processor speed: 1 MHz
Memory: 2,048 words (32,768 bits or roughly 4kB)
Display: Seven-segment numeric
Price: $150,000 (est.) (Today's equivalent of about $20 million)
Apple iPhone 5s
Dimensions: 4.87 inches x 2.31 inches
Weight: 3.95 ounces
Processor speed: 1.3GHz, dual-core
Memory: 64GB
Display: 4-inch diagonal Multi-Touch display, 1136 x 640 pixel resolution at 326 ppi
Price: $399
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These people who developed the computer are in my opinion heroes of mankind who deserve accolades and whose names should be enshrined. Instead, most people have never heard of these great pioneers of technology but they all know about celebrities like that twerp Bieber and barge-arse Kim who have produced nothing of value to humanity.
No arguments there. I have a neighbor whose father was a scientist at JPL during the 60's. Feeding him bourbon and getting him to talk about his time during the space program is the best time there is. :-+
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With all the stuff on the Internet this is a good time to be a space geek.
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I have the same T-shirt as Fran (JPL). I have two kids in the right age so I managed to get onto the school tour at JPL in Pasadena twice!
The Apollo Guidance Computer (AGC) is very interesting as it is one of the very few that used integrated circuits. At the time, NASA bought about 80% of the IC production in the U.S. The AGC was designed at the Instrumentation Laboratory at MIT since they had experience with inertial guidance systems (a bunch of gyros and accelerometers that figured out the current location in 3D-space). The whole thing turned into a big mess because the software written for the thing was an unstructured mess; it got so bad that the whole Apollo program was at risk of not going to the moon "before the end of the decade" (1969/70). At the end, the software was sorted out but the inertial guidance system was actually only used as a secondary navigation. Instead ground-based navigation was done via telemetry. They did cross-check, though, and the AGC was dead-on so it actually worked. I'm not sure whether they flew any missions relying exclusively on the AGC navigation.
And, no, the astronauts certainly did not know the whole instruction repertoire off the top of their heads; rather they went from check-lists and instructions from the ground when they needed to enter new program code into the AGC.
Finally, here is another Youtube video about the AGC (from "Moon Machines" series) : https://www.youtube.com/watch?v=9YA7X5we8ng&list=PLTu8nanTJo7GvulBxz9JT9JcXeXimM1Vr&index=3 (https://www.youtube.com/watch?v=9YA7X5we8ng&list=PLTu8nanTJo7GvulBxz9JT9JcXeXimM1Vr&index=3)
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Apollo Guidance Computer (AGC)
Dimensions: 24 x 12.5 x 6.5 inches
Weight: 70 pounds
Processor speed: 2.048 MHz
Memory: 2,048 words (32,768 bits or roughly 4kB) RAM, 36,864 words (roughly 72kB) ROM.
Display: Seven-segment numeric
Price: $150,000 (est.) (Today's equivalent of about $20 million)
Apple iPhone 5s
Dimensions: 4.87 inches x 2.31 inches
Weight: 3.95 ounces
Processor speed: 1.3GHz, dual-core
Memory: 1GB RAM, 16 or 32 or 64GB none volatile.
Display: 4-inch diagonal Multi-Touch display, 1136 x 640 pixel resolution at 326 ppi
Price: $399
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These people who developed the computer are in my opinion heroes of mankind who deserve accolades and whose names should be enshrined. Instead, most people have never heard of these great pioneers of technology but they all know about celebrities like that twerp Bieber and barge-arse Kim who have produced nothing of value to humanity.
Apollo Guidance Computer (AGC)
Dimensions: 24 x 12.5 x 6.5 inches
Weight: 70 pounds
Processor speed: 1 MHz
Memory: 2,048 words (32,768 bits or roughly 4kB)
Display: Seven-segment numeric
Price: $150,000 (est.) (Today's equivalent of about $20 million)
Arduino Mega
Dimensions: 4 x 2 x 0.5 inches
Weight: 0.082 pounds
Processor speed: 16 MHz
Memory: 256kB flash, 8kB SRAM, 4kB EEPROM
Display: plenty of shields to choose from
Price: $40
Anyone tried to recreate a fully functional Apollo Guidance Computer using an Arduino with a display shield slapped on it?
The specs suggest it should be possible...
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Fixing position was one of the functions of the apollo computer. It had many more including passive thermal balance of the spacecraft (PTC). Named the "barbecue" mode which put the spacecraft in a roll to evenly distribute the heat thus reducing the requirements in heat shielding and weight.
One of great importance was the reentry guidance and control during the atmospheric phase.
Also maneuvers like TLI were performed by initiating the corresponding routines issuing the verb and noun. The computer then pointed the spacecraft in the right direction, eliminated the slosh of the fuel in the tanks by a small burn in the motor and made the burn and steering required to place the spacecraft in course.
https://en.wikipedia.org/wiki/Apollo_PGNCS
Who's in charge?
Despite the word "primary" in its name, PGNCS data was not the main source of navigation information. Tracking data from NASA’s Deep Space Network was processed by computers at Mission Control, using least squares algorithms. The position and velocity estimates that resulted were more accurate than those produced by PGNCS. As a result, the astronauts were periodically given state vector updates to enter into the AGC, based on ground data. PGNCS was still essential to maintain spacecraft orientation, to control rockets during maneuvering burns, including lunar landing and take off, and as the prime source of navigation data during planned and unexpected communications outages. PGNCS also provided a check on ground data.