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Topic: Apollo Guidance Computer |
b0b
From:
Cloverdale, CA, USA
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Bent Romnes
From:
London,Ontario, Canada
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Posted 13 Feb 2008 4:29 pm |
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| Cool alright. I especially loved the part about 1Mhz clock speed. My computer has 3.2 Ghz |
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Jack Stoner
From:
Kansas City, MO
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Posted 14 Feb 2008 4:27 am
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I worked on the Apollo project - First as a UHF command tech and then as a PCM Telemetry Tech/Engineer (The PCM Telemetry "dcommutators" were special purpose computers) and later as the lead programmer on the telemetry decommutators (processors).
The Apollo "decom's" had a 4KB (32 bit words) core memory and used a paper tape (8 bit ASCII) as the input for loading programs. There wasn't any CRT screen on them. Had a lot of lights that we could display registers (for the processing) and for data display. They did have some "nixie" tubes for digital display if a D/A parameter needed displaying. One Telemetry Processor was three 5ft high cabinets of equipment. The Telemetry processors took the downling Telemetry data from the spacecraft "decommutated" the data (the data stream was a time division multiplex signal, very similar to the digital data scheme that is used for a "T1" data stream). The output of the Telemetry processors were transferred to a Univac computer on the tracking station for further processing and ultimately sent to the NASA control center in Houston.
Last edited by Jack Stoner on 14 Feb 2008 10:19 am; edited 1 time in total |
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b0b
From:
Cloverdale, CA, USA
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Posted 14 Feb 2008 8:06 am
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4 MB??  Whoa! |
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Jack Stoner
From:
Kansas City, MO
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Posted 14 Feb 2008 10:34 am
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Bob, I amended it, the machine had a grand total of 4KB of core memory! We had to be very "creative" when programming that machine to be able to get everything that needed to be done for Apollo (all the various programs (called "formats")) that needed to be loaded for each Apollo mission. That was my first introduction to "global routines" that could be used by more than 1 "format".
The next version Telemetry Processor, that was built for the Skylab project had big time memory - an 8K 24bit words core memory. It was the first solid state model that NASA had (the predecessor to the model I first mentioned was built for the Gemini project and it had a patch panel that set up the program in that dude. Anyway the next generation model was solid state (mostly 7400 series IC's) and the ALU in the processor was the two chip Texas Instrument calculator chipset, unique then but obviouisly very crude by today's standards. We came up in the world and had a BAL compiler (assembler) for programming that machine. |
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Bent Romnes
From:
London,Ontario, Canada
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Posted 14 Feb 2008 1:03 pm
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Jack, I guess you got in on the ground floor as far as computers go!
My guess is that what you don't know isn't worth knowing! My hat off to you, sir! |
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b0b
From:
Cloverdale, CA, USA
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Posted 14 Feb 2008 8:40 pm
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| I figured it must have been a typo, Jack. Congrats on your role in that historic event. |
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Jack Stoner
From:
Kansas City, MO
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Posted 15 Feb 2008 4:50 am
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b0b, thanks.
I have a Commemorative coin that was presented to our Apollo support team that was struck from from metal brought back from the moon that came from the Apollo 11 "Eagle" lunar spacecraft (part of the metal was from the Eagle). It was part of the recognition we got for the project along with a nice $$ bonus.
Another side note on our programming section. We were all tech's on the equipment prior to getting into the Programming end. For that reason we became the "tech support" for the Telemetry Processors and if a Tracking Station had a hardware problem that they couldn't resolve we were called on to assist the remote stations in getting the Processor fixed. That was sort of a "hot seat" job, if a piece of equipment was "down" it could affect real time data collection from the Spacecraft from that station, Everything in the spacecraft is monitored and sent to Houston - all switches (on or off), All voltages, oxygen levels, cabin air pressure, Astronauts EKG and respiration rates,etc and it was all sent down on the Telemetry downlink data stream. |
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