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Monday, 13 June 2016

Apollo Guidance Computer

Here you'll find a collection of all the AGC, AGS, LVDC, and Gemini spacecraft computer documentation and software that I've managed to find whilst working on  Virtual AGC.  Every document on this page is archived here at Virtual AGC, regardless of whether it originated here or not.  In the early days I used to include only material I uncovered by my own efforts, but there have increasingly been contributions by readers, including some of the original AGC developers.  And there's material here that has been duplicated from other Apollo-centric websites for your convenience; see the FAQ page for a list of the fine Apollo and Gemini websites I raided. Now, there is some value-added in this process, since I add searchable text to those PDFs which are image-only, as well as adding metadata and bookmark panes where they don't exist.  My intention is to eventually provide one-stop-shopping for all of your Apollo and Gemini computing-system documentation needs. Note however, that I choose to duplicate only scanned or photographic images of the original documents.  In other words, I provide something as close to the "real thing" as I can.  On some sites, notably the Apollo Flight Journal and Apollo Lunar Surface Journal, great pains have been taken to produce HTML forms of the documents.  I do not duplicate those improved reformulations here, because that's original work for which I think credit is due; so you will have to visit those sites to use those improved versions.

Document categories

 AGC software manuals and listings

  • Convenient HTML forms of AGC program listings, with syntax colorization, cross-reference hyperlinks, and (a little) annotation:
  • Or alternately, very large scanned page images of AGC program listings, if you'd like to see a crummy, compressed form of what the actual AGC developers saw:
  • E-1077:  Preliminary MOD 3C Programmers Manual, by R. Alonso, J. H. Laning, Jr., and H. Blair-Smith, November 1961.  (84 pages, 2.7M bytes.)  This manual applies to an earlier version of the AGC, but is still very interesting since it includes topics like the YUL assembler.
  • AGC4 Memo # 9 - Block II Instructions (1966), by Hugh Blair-Smith.  This is the source for info on AGC assembly language.  See also pages 30-50, provided as etext by Hugh Blair-Smith (rather than being scanned) just for us.  Incidentally, I've taken to calling this the "infamous memo", simply because I think it's funny, but I notice that this phrase is being duplicated across the web.  I don't actually know that there's anything infamous about it, so if you plan to quote me, please leave out the word "infamous".   
  • E-2052:  AGC4 Basic Training Manual, Volume I, by Bernard Savage and Alice Drake, January 1967.  (118 pages, 3.9M bytes.)
  • "Users Guide to the Block II AGC/LGC Interpreter", by Charles A. Muntz. (1965, 3 Mbytes).

Guidance System Operations Plans (GSOP)

    AGC quick-reference cards or data cards

    • Apollo 15 Colossus 3 CMC Data Cards (36 pages, 1.5M bytes).  Same but for Apollo 15 CM.  (Contributed by Fabrizio Bernardini.)  Also, Apollo 15 CMC data cards.  (This is a cleaned up version of the scanned cards.  Thanks, Fabrizio!)
    • Apollo 15 Luminary 1E LGC Data Cards, (42 pages, 8.3M bytes).  Same but for Apollo 15 LM.  (Contributed by Fabrizio Bernardini.)  Sorry, but this is a zipfile of JPEGs rather than a PDF file, because that's the only way I could keep the size even marginally manageable.  These sets of reference cards tend to have funky background colors, and some colors are easier to scan than others.  The JPEGs should be very readable, but the scans Fabrizio sent me are much better than what I'm posting (again, for size reasons), so if you need better scans you should let me know.
    • Skylab quick-reference cards.  (36 pages, 1.2M bytes.)  The Apollo CM spacecraft used for the Skylab project ran a program called Skylark on their AGCs.  These quick-reference cards, presumably used for training flight controllers, packed a lot of info about Skylark (and indirectly about Colossus and to a lesser extent Luminary) in a very concise package.  
    • Apollo-Soyuz quick-reference cards (38 pages, 1.2M bytes) are the same idea, except that they were used for the Apollo-Soyuz test project.

    AGC pad loads

    Space Guidance Analysis (SGA) memos

    If you are interested in the mathematical underpinnings of the AGC software, then this amazing series of memos from MIT's Instrumentation Lab is the place to look.  The memos are in roughly chronological order.  It is very interesting to reflect on the fact that these mathematical memos are often written by the very same people whose names you find as authors in the software.  The AGC software was written in a time ... or at least a place ... where software was regarded as the expression of mathematical knowledge as opposed to being a mere exercise in the expert employment of programming languages and tools as it is today.  It is interesting also to reflect on the nature of the software this approach produced.

    Apollo Experience Reports

    Miscellaneous Guidance & Navigation

    These items are alphabetical by author.  (Where the "author" is an organization rather than a person, I consider the author to be "Anonymous".)  These items are mostly documents are from our (improved) archive of the now sadly defunct AGC website of MIT's Dibner Institute for the History of Recent Science and Technology.  (Yes, there is some duplication here, but otherwise it becomes all too easy to lose documents because they're smeared across multiple web-pages.)

    Abort Guidance System (AGS) and its computer (AEA)

    As inadequate as our AGC documentation collection is, our AGS documentation collection lags far behind.  All of the available documentation was digitized by John Pultorak from physical documents preserved and donated by Davis Peticolas.

    Launch Vehicle Digital Computer (LVDC)

    We have precious little LVDC documentation of any kind, and no LVDC software at all.  The Wikipedia article on the LVDC laments that all of the LVDC software has probably vanished and does not exist any longer.  Well, I don't believe that.  (They're smart enough to send a man to the moon, but too stupid to put the documents in a file cabinet afterward?  I hope not!)  There must be some former LVDC developer somewhere who was proud enough of his work to retain some souvenirs.  If you know any LVDC developers, please help us to get in contact with them.

    Systems Handbooks

    • Lunar Module Systems Handbook:
      • Excerpts from LM-5 through LM-9, June 1969 (13 pages, 29M bytes).  This is a large download because it consists of beautiful hi-res scans of very large schematic foldouts.  (Contributed by Paul Fjeld.)
      • Excerpts from Apollo 17 (3 pages 5M bytes).  Sadly, these scans are not of the highest quality.  If you seek general information rather than Apollo 17 specific information, I'd suggest the item above or the item below instead.  (Contributed by Fabrizio Bernardini.)
    • Command and Service Module Systems Handbook:
      • Excerpt:  Guidance & navigation section for handbook of CSM 112 through 114, March 12, 1971 (29 pages, 20M bytes).  (Contributed by Fabrizio Bernardini.)

      Operations Handbooks

      Operational Data Books

      • "G", "H", and "J" missions: CSM/LM Spacecraft Operational Data Book:

        Technical Crew Debriefings

        Mission Reports

        Flight Plans


        Familiarization Manuals

        General Apollo documents unrelated to computing systems

        Press Kits and Releases


        Gemini spacecraft computer