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
- Apollo Guidance Computer (AGC):
- AGC software language manuals and program listings
- Guidance Systems Operations Plans (GSOPs)
- AGC guick-reference cards or data cards
- AGC Pad loads
- Space Guidance Analysis (SGA) memos
- Apollo Experience Reports
- Miscellaneous Guidance & Navigation
- Abort Guidance System (AGS) and its computer (AEA)
- Launch Vehicle Digital Computer (LVDC)
- Mission-specific or spacecraft-specific info:
- Systems Handbooks
- Operations Handbooks
- Operational Data Books
- Technical Crew Debriefings
- Mission Reports
- Flight Plans
- Checklists
- Familiarization Manuals
- General Apollo documents unrelated to computing systems
- Gemini spacecraft computer
AGC software manuals and listings
- Convenient HTML forms of AGC program listings, with syntax colorization, cross-reference hyperlinks, and (a little) annotation:
- Apollo 4 CM (Solarium 55)
- Apollo 8 CM (Colossus 237)
- Apollo 9 CM (Colossus 249)
- Apollo 11 CM (Comanche 55)
- Apollo 11 LM (Luminary 99)
- Apollo 13 LM (Luminary 131)
- Apollo 15-17 CM (Artemis 72)
- 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:
- Apollo 4 CM (Solarium 55)
- Apollo 8 CM (Colossus 237)
- Apollo 9 CM (Colossus 249), from Fred Martin's copy (better images)
- Apollo 9 CM (Colossus 249), from Norm Brodeur's copy (not as legible)
- Apollo 11 CM (Comanche 55)
- Apollo 11 LM (Luminary 99)
- Apollo 13 LM (Luminary 131)
- Apollo 15-17 CM (Artemis 72)
- 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)
- AS - 278: R-547: Guidance System Operations Plan AS-278. AS-278 was a cancelled mission (because of Apollo 1), which would have been the first orbital test of the LM. Instead, the same crew provided that first test in Apollo 9, at a much later date.
- Volume 1, "CM GNCS Operations" (1966, 18 Mbytes).
- Preliminary Lunar Landing Mission GSOP
- Section 5, "CMC Guidance & Navigation Equations"
- Section 5, "LGC Guidance & Navigation Equations"
- Apollo 5 Lunar Module: R-527: Guidance System Operations Plan for Unmanned LM Earth Orbital Missions Using Program Sunburst:
- Section 7, "G&N Error Analysis".
- Apollo 8 & 9 Command Module: R-577: Guidance System Operations Plan for Manned CM Earth Orbital and Lunar Missions Using Program Colossus 1 (Rev. 237) and Program Colossus 1A (Rev. 249). Don't be fooled by the name "operations plan". This is detailed technical documentation specific to the mentioned versions of Colossus---and of course, Colossus 1A build 249 is the version we are actually using. The "operation plan" is something like a "user manual" for the guidance system (and hence for the AGC as well). The complete document scan is about 1840 pages (43M bytes), so I've split it into smaller chunks for more-sensible downloading.
- Section 1, Rev. 1: "Pre-Launch". (59 pages, 1.5M bytes.)
- Section 2, Rev. 2: "Data Links". (138 pages, 4.5M bytes.)
- Section 3, Rev. 3: "Digital Autopilots". (219 pages, 6.9M bytes.)
- Section 4, Rev. 6: "GNCS Operations":
- Introductory sections. (48 pages, 1.4M bytes.)
- Programs P00 through P27. (116 pages, 1.9M bytes.)
- Programs P30 through P39. (96 pages, 1.7M bytes.)
- Programs P40 through P67. (130 pages, 2.2M bytes.)
- Program P70 through Routine R32. (144 pages, 2.4M bytes.)
- Routine R33 through Verb 41. (131 pages, 1.9M bytes.)
- Verb 42 and beyond. (164 pages, 1.9M bytes.)
- Section 5, Rev. 4: "Guidance Equations":
- Through section 5.2. (151 pages, 3.7M bytes.)
- Sections 5.3 through 5.5. (198 pages, 5.4M bytes.)
- Sections 5.6 and beyond. (145 pages, 3.0M bytes.)
- Section 6, Rev. 1: "Control Data". (102 pages, 2.3M bytes.)
- Apollo 9 & 10 Lunar Module: R-557: Guidance System Operations Plan for Manned LM Earth Orbital Missions Using Program Sundance 306, and Program Luminary 069:
- Apollo 13 Lunar Module: R-567: Guidance System Operations Plan for Manned LM Earth Orbital and Lunar Missions Using Program Luminary 1C (Rev. 131). The complete document scan is about 2300 pages (45M bytes), so I've split it into smaller chunks for more-sensible downloading:
- Section 1, Rev. 1. (62 pages, 1.7M bytes.) Actually, I took this section from document R-557: Guidance System Operations Plan for Manned LM Earth Orbital Missions Using Program Sundance 306, and Program Luminary 069. Refer to page v of the document for an explanation of this oddity. Unfortunately, there is presently no way to know if this is the correct revision of this section, but it was the latest revision I was able to find.
- Section 2, Rev. 8: "Data Links". (146 pages, 4.7M bytes.)
- Section 3, Rev. 4: "Digital Autopilot". (194 pages, 8.0M bytes.)
- Section 4, Rev. 7: "PGNCS Operational Modes."
- Introductory sections. (102 pages, 2.4 M bytes.)
- Programs P00 through P39. (226 pages, 4.2M bytes.)
- Programs P40 through P69. (226, 4.4M bytes.)
- Program P70 through routine R09. (192 pages, 3.3M bytes.)
- Routines R10 through R56. (246 pages, 2.4M bytes).
- Routine R57 through end of section. (260 pages, 1.8M bytes.)
- Section 5, Rev. 8: "Guidance Equations"
- Sections 5.1-5.2. (136 pages, 2.3M bytes.)
- Section 5.3. (180 pages, 3.1M bytes.)
- Section 5.4-5.5. (98 pages, 1.3M bytes.)
- Sections 5.6 and up. (144 pages, 2.2M bytes.)
- Section 6: "Control Data". (84 pages, 1.7M bytes.) Unfortunately, there is presently no way to know for sure if this is the correct revision of this section, but it was the only revision I was able to find. The document specifically refers to spacecraft CM-107 (used on Apollo 11) and LM-6 (used on Apollo 12), so it's not unreasonable to suppose that it is a fairly mature revision of the document. (Recall that we believe Luminary 1C 131 was used for Apollo 13.)
- Apollo 10 Command Module: R-577: Guidance System Operations Plan for Manned CM Earth Orbital and Lunar Missions Using Program Colossus 2 (Comanche Rev. 44,45). (Thanks to original AGC developer Fred Martin!)
- Section 5, Rev. 5: "Guidance Equations".
- Section 5.1: "Introduction"
- Section 5.2: "Coasting Flight Navigation"
- Section 5.3: "Powered Flight Navigation and Guidance"
- Section 5.4: "Targeting Routines"
- Section 5.5: "Basic Subroutines"
- Section 5.6-5.9: "General Service Routines", "Entry Guidance", "Erasable Memory Parameter List", and "Fixed Memory Constants"
- Apollo 15-17 Command Module: R-577: Guidance System Operations Plan for Manned CM Earth Orbital and Lunar Missions Using Program Colossus 3. (Thanks to Shelly Kelly and the crew at U. H. Clear Lake!) Note that several sections are actually taken from the Colossus 2E GSOP rather than the Colossus 3 GSOP. Colossus 3 software was used for Apollo 15-17, while Colossus 2E software was used for Apollo 14. The GSOP documents were modular, and so sections from various missions might be mixed-and-matched to make a complete document, but I don't have a list of the revision levels appropriate to Colossus 3. So it's possible that the Colossus 2E sections exactly right; the most I can say right now, though, is that they're the closest thing we have to Colossus 3 docs.
- Section 1, Rev. 2: "Pre-Launch" (Colossus 2E, 61 pages, 2.8M bytes.)
- Section 2, Rev. 14: "Data Links". (Colossus 3, 155 pages, 5.6M bytes.)
- Section 3, Rev. 11: "Digital Autopilot". (Colossus 2E, 244 pages, 8M bytes.)
- Section 4: "PGNCS Operational Modes".
- Section 5, Rev. 14: "Guidance Equations". (Colossus 3, 493 pages, 11.3M bytes.)
- Section 6: "Control Data".
- Section 7, Rev. 01: "Erasable Memory Programs". (Colossus 3, 98 pages, 2M bytes.)
- Apollo 15-17 Lunar Module: R-567: Guidance System Operations Plan for Manned LM Earth Orbital and Lunar Missions Using Program Luminary 1E:
- Section 2, Rev. 12: "Data Links".
- Section 7: "Erasable Memory Programs".
- Apollo/Skylab and/or Apollo/Soyuz: R-693: Guidance System Operations Plan for Manned CM Earth Orbital Missions Using Program Skylark 1:
- Section 2: "Data Links"
- Section 4, Rev. 01: "Operational Modes"
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
- Apollo 11: Pad loads for LM-5. (19 pages, 6M bytes. Contributed by Paul Fjeld.)
- Apollo 13: Pad loads for LM-7. (21 pages, 1M bytes. Contributed by Paul Fjeld.)
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.
- Memo #9 1962: "Precise Circumlunar trajectory Calculations" by R. H. Battin.
- Memo #11 1962: "SGA Studies Presently Underway" by Richard H. Battin.
- Memo #12 1962: "Storing Position of Moon" by James E. Potter.
- Memo #20 1962: "Optimum Use of Acceleration Measurements to Determine Altitude-Rate During Re-entry" by Bard S. Crawford.
- Memo #22 1962: "Calculation of the Roots of u C (u) = A" by James E. Potter.
- Memo #25 1962: "Guidance Dynamic Requirements on SCS" by E. M. Copps.
- Memo #26 1962: "Investigation of Minimum Mid-Course Attitude Maneuvers" by C. A. Muntz and J. E. Potter.
- Memo #29 1962: "Error Ellipsoids" by James E. Potter.
- Memo #44 1963: "Optimization of Midcourse Correction Times" by Robert J. Fitzgerald.
- Memo #52 1963: "Midcourse Guidance" by Gerald M. Levine.
- Memo #56 1963: "Deriving Random Error Vectors from Covariance Matrix" by R. D. Goss and E. S. Muller.
- Memo #57 1963: "Coordinate System Used in the Moon Position Subroutine" by Larry D. Brock.
- Memo #1 1964: "Effects of Correlated Measurement Errors on Midcourse Performance" by Peter J. Philliou.
- Memo #2 1964: "Primary G&N Rendezvous Guidance Equations" by E. S. Muller and N. E. Sears.
- Memo #11 1964: "The Transition Matrix for a Circular Orbit" by Gerald M. Levine.
- Memo #23 1964: "Universal Conic Time of Flight Computations" by William Marscher.
- Memo #25 1964: "Midcourse Monte Carlo Simulation Model" by Gerald M. Levine.
- Memo #32 1964: "ROOTFINDER 3 -- 20th Order Polynomial Factoring Program" by Robert W. Baker.
- Memo #34 1964: "Orbital Navigation Using Unknown Landmarks" by Gerald M. Levine.
- Memo #35 1964: "Optimization of Reentry 'Up-Phase' Guidance" by Bard S. Crawford.
- Memo #37 1964: "Computer Program Description -- Root Locus Technique" by Donald Fraser.
- Memo #38 1964: "Optimal Guidance Laws" by Peter J. Philliou.
- Memo #48 1964: "Collection of Conic Equations" by William Marscher.
- Memo #49 1964: "Noise Through a Derived Rate Controller" by Edward M. Copps, Jr.
- Memo #2 1965: "A Modified Encke" by William Marscher.
- Memo #3 1965: "A Generalized Solution to the Impulsive Guidance Problem" by Wayne Tempelman.
- Memo #8 1965: "An Analysis of Control of Track Deviation During Lunar Deboost" by E. M. Copps, Jr.
- Memo #10 1965: "b-Vectors for Angle and Angle Rate Measurements in Arbitrary Coordinate System" by E. S. Muller.
- Memo #14 1965: "Time to go and Delta-v" by Edward M. Copps, Jr.
- Memo #20 1965: "Notes for Ephemeris Programs for the AGC" by Larry Brock.
- Memo #25 1965: "Equations for non-optimum estimate of mean square mid-course velocity correction" by E. S. Muller and R. J. Phaneuf.
- Memo #28 1965: "Conic Time of Flight Calculations to Radius of Specified Length" by Robert Bairnsfather.
- Memo #29 1965: "Recursive Filtering Applied to System Identification" by Donald C. Fraser.
- Memo #32 1965: "Updating the Determinant of the Covariance Matrix" by Donald C. Fraser.
- Memo (unnumbered) 1966: "The Coriolis Equation" by A. R. Klumpp.
- Memo #1 1966: "Apollo Spacecraft-Engine Equations and Actuator Load" by T. C. Lu.
- Memo #2 1966: "Some Minor Discrepancies between the performance of the AGC4 Block I Interpreter and its R-467 specifications" by Roy Beasley.
- Memo #3 1966: "Derivation of the Optimum Control Program for Steering the LEM Using the Gimballed Descent Engine" by William S. Widnall.
- Memo #4 1966: "Controlling the Attitude and Attitude Rate of the LEM with the Gimballed Descent Propulsion System" by George W. Cherry.
- Memo (unnumbered) 1966: "Interpretation of Vector Quantities in the Coriolis Equation" by P. C. Watson.
- Memo (unnumbered) 1966: "The Coriolis Equation — A Sequel" by D. S. Baker.
- Memo (unnumbered) 1966: "More on Coriolis" by Allan Klumpp.
- Memo #10 1966: "The Minimum Fuel Return Problem" by Kurth Krause.
- Memo #12 1966: "Characteristics of Entry Starting at 300,000 Feet" by Ray Morth.
- Memo #16 1966: "Gimbal Lock Avoidance Schemes" by Raymond Morth.
- Memo #17 1966: "A Computer Program for Block Diagram Reduction" by Donald C. Fraser.
- Memo #3 1967: "Constraints on Selecting b-Vectors to Represent Measurements" by P. Kachmar and E. Muller.
- Memo #7 1967: "Correcting Fixed Dimension Kalman Gain Vectors to Account for Colored Measurement Noise" by Donald C. Fraser.
- Memo #8 1967: "Explicit Universal Series Solutions for the Universal Variable x" by William M. Robertson.
- Memo #9 1967: "A Recursive CG Correction Scheme" by Edward Womble.
- Memo #15 1967: "Preliminary Design of the RCS Autopilots Required for Task 2 of the Apollo Application Program" by Edward Womble.
- Memo #5 1968: "A Modified Acceleration Expression for Bodies in Gravitation Fields" by Wayne H. Tempelman.
- Memo #2 1969: "Inclusion of Biases in Statistical Midcourse Navigation" by David Baker.
- Memo #8 1971: "Concise Analytic Approximations to the Sun's Geocentric Position Vector" by W. M. Robertson.
- Memo #8 1971, addendum: "Incorporation of the Advance of Perihelion into Concise Analytic Approximations to the Sun's Geocentric Position Vector", by W. M. Robertson.
Apollo Experience Reports
- "Flight-Control Data Needs, Terminal Display Devices, and Ground System Configuration Requirements" by Richard A. Hoover.
- Guidance and Control Systems:
- "Automated Control System for Unmanned Mission AS-201" by Gene F. Holloway.
- "Lunar Module Abort Guidance System" by Pat M. Kurten.
- "Lunar Module Mission Programer" by Jesse A. Vernon.
- "Mission Control Programer for Unmanned Missions AS-202, Apollo 4, and Apollo 6" by Gene F. Holloway
- "Primary Guidance, Navigation, and Control System Development", by M. D. Holley, W. L. Swingle, S. L. Bachman, C. J. LeBlanc, H. T. Howard, and H. M. Biggs.
- "Onboard Navigational and Alignment Software" by Robert T. Savely, Bedford F. Cockrell, and Samuel Pines.
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.)
- Ramon L. Alonso, Hugh Blair-Smith, and Albert L. Hopkins, Some Aspects of the Logical Design of a Control Computer: A Case Study (1971).
- Ramon L. Alonso et al., A Digital Control Computer Developmental Model 1B (1962, 12 Mbytes).
- Ramon L. Alonso and Albert L. Hopkins, The Apollo Guidance Computer (1963, 3 Mbytes).
- Ramon L. Alonso, Albert L. Hopkins, and Herbert A. Thaler, A Multiprocessing Structure (1967).
- Ramon L. Alonso and J. Hal Laning, Design Principles for a General Control Computer (1960, 4 Mbytes).
- Anonymous, Apollo 15 Electronics manual, by Delco Electronics. This document seems to have no title, document number, date, or revision, but it is the most useful source in most respects for information about interfacing the AGC to the remainder of the guidance system. (Scanned by Frank O'Brien for the Apollo Flight Journal / Apollo Lunar Surface Journal websites.)
- Anonymous, Apollo Guidance and Navigation Lunar Module Student Study Guide, by AC Electronics. (1967, 9 Mbytes).
- Anonymous, Guidance and Navigation, July 1965, training slides.
- Anonymous, Guidance and Control, February 1967, training slides.
- Anonymous, Guidance and Control, September 1967, training slides.
- Anonymous, MSC05225, 71-FS-5: Program Notes for Colossus 3 and Luminary 1E J-Series Missions Flight Programs, Rev. 1, September 1972 (54 pages, 1.5M bytes). Program notes written by the MSC Simulation and Flight Software Branch. (Contributed by Fabrizio Bernardini.)
- Anonymous, LEM CES and AGS, September 1966 (32 pages, 800K bytes). This is a set of block diagrams and other high-level data concerning the LEM. It is excerpted from a larger training course by Grumman. (Contributed by Fabrizio Bernardini.)
- Anonymous, excerpts from LEM Guidance, Navigation, and Control Subsystem Course No. 30315, 30415, March 1966 (40 pages, 8M bytes). Excerpts from a Grumman study guide. (Contributed by Fabrizio Bernardini.)
- Anonymous, beautiful photos of an early LM control panel (September 1968) and the LMP's panel (Apollo 14). (Contributed by Paul Fjeld.)
- Anonymous, Drawings of LM structures. (Contributed by Paul Fjeld.)
- Anonymous, The Apollo 11 Adventure. (247 pages, 8.8M bytes.) A quirkily geekish retrospective of the Apollo missions through Apollo 11, from the perspective of the Mission Planning and Analysis Division. (Digitized by me at the National Archives.)
- Anonymous, Astronauts' Guidance and Navigation Course Notes (1962, 3 Mbytes).
- Anonymous, More Apollo Guidance Flexibility Sought (1964).
- Anonymous, Control of Flight Software Development Costs (1971).
- Anonymous, Apollo/Skylab ASTP and Shuttle Orbiter Major End Items (1978).
- R. Battin et al., The Compleat Sunrise being a description of Program Sunrise (Sunrise 33 - NASA DWG# 1021102) (1964, 4 Mbytes).
- Hugh Blair-Smith, Annotations for Eldon Hall's book, Journey to the Moon: The History of the Apollo Guidance Computer (1997). This is an etext created by Mr. Hugh Blair-Smith, rather than a scan of a historical document.
- Hugh Blair-Smith, YUL System - Pass 0 (4 Mbytes).
- Edward M. Copps Jr., Recovery from Transient Failures of the Apollo Guidance Computer (1968).
- Robert Crisp and D. Keene, Apollo Command and Service Module Reaction Control by the Digital Autopilot (1968).
- C. S. Draper volunteering to become an astronaut, and Robert Seamans replying (1961).
- C. S. Draper et al., Space Navigation Guidance and Control. Volume I. (1965, 7 Mbytes).
- C. S. Draper et al., Space Navigation Guidance and Control. Volume II. (1965, 12 Mbytes).
- Charles M. Duke Jr. and Michael S. Jones, Human Performance during a Simulated Apollo Mid-Course Navigation Sighting (1964, 5 Mbytes).
- J. C. Dunbar, R. A. Larson and P. T. Augart, An Automated Documentation Technique for Integrating Apollo Crew Procedures and Computer Logic (1966).
- Maxime A. Faget, The Evolution of Flight Control of the Apollo Mission (1976).
- Philip G. Felleman, Hybrid Simulation of the Apollo Guidance Navigation and Control System (1966).
- F. K. Glick and S. R. Femino, A Comprehensive Digital Simulation for the Verification of Apollo Flight Software (1970).
- Alan Green, Digital Development Memo #267: Vlock II Keyboard and Display Program (1965).
- Alan Green, Keyboard and Display Program and Operation (1967, 4 Mbytes).
- Alan I. Green and Robert J. Filene, Keyboard and Display Program and Operation (1967).
- The Guidance Software Validation Committee, Apollo Guidance Software Development and Validation Plan (1967).
- Eldon C Hall, The Apollo Guidance Computer - A Designer's View (1982).
- Eldon C Hall, Case History of the Apollo Guidance Computer (1966, 3 Mbytes).
- Eldon C Hall, A Case history of the AGC Integrated Logic Circuits (1965).
- Eldon C Hall, Computer Displays (1962).
- Eldon C Hall, From the Farm to Pioneering with Digital Computers: An Autobiography (2000).
- Eldon C Hall, General Design Characteristics of the Apollo Guidance Computer (1963, 3 Mbytes).
- Eldon C Hall, MIT's Role in Project Apollo, Vol. III: Computer Subsystem (1972, 11 Mbytes).
- Eldon C Hall, Reliability History of the Apollo Guidance Computer (1972).
- Eldon C Hall and Richard Jansson, Miniature Packaging of Electronics in Three-Dimensional Form (1959, 5 Mbytes).
- James A. Hand, Computer-Aided Inertial Platform Realignment in Manned Space Flight (1968, 31 Mbytes).
- James A. Hand, MIT's Role in Project Apollo, Vol. I: Project Management, Systems Development, Abstracts and Bibliography (1971, 13 Mbytes).
- David L. Hanley, Jayne Partridge, and Eldon C. Hall, The Application of Failure Analysis in Procuring and Screening of Integrated Circuits (1965, 3 Mbytes).
- W. G. Heffron, Bellcomm memorandum, "S/C 101 Software First Article Configuration Inspection", Sundisk software.
- David G. Hoag, Apollo Navigation, Guidance, and Control Systems: A Progress Report (1969, 4 Mbytes).
- David G. Hoag, The History of Apollo On Board Guidance and Navigation (1976).
- David G. Hoag, LEM Guidance Computer Programs to be Supplied by MIT (1965).
- C. Lester Hogan, "Types of Integrated Circuits" (1964) [Magazine Article].
- M. D. Holley, W. L. Swingle, S. L. Bachman, C. J. LeBlanc, H. T. Howard, and H. M. Biggs, "Apollo Experience Report—Guidance and Control Systems: Primary Guidance, Navigation, and Control System Development", NASA Technical Note D-8227.
- Richard A. Hoover, "Apollo Experience Report—Flight-Control Data Needs, Terminal Display Devices, and Ground System Configuration Requirements", NASA Technical Note D-7685.
- Albert L. Hopkins Jr., Ramon Alonso, and Hugh Blair-Smith, "Logical Description for the Apollo Guidance Computer (AGC4)" (1963, 10 Mbytes) [Report].
- Albert L. Hopkins, "A Fault-Tolerant Information Processing Concept for Space Vehicles." (1970) [Report].
- Madeline S. Johnson, "A list of titles and authors", MSJ Memo #7-69. I deduce from this numbering scheme that Madeline must have written a lot of memos. :)
- Madeline S. Johnson and Donald R. Giller, "MIT's Role in Project Apollo, Vol. V: The Software Effort." (1971, 30 Mbytes) [Report].
- Malcolm W Johnston, "A Manual LEM Backup Guidance System." (1964) [Report].
- David N. Kaye, "The Indispensible Men" (1969) [Magazine Article].
- W. M. Keese et al., "Management Procedures in Computer Programming for Apollo - Interim Report" (1964) [Report].
- Allan R. Klumpp, "A Manually Retargeted Automatic Descent and Landing System for LEM" (1966, 3 Mbytes) [Report].
- J. Hal Laning and N. Zierler, "A Program for Translation of Mathematical Equations for Whirlwind I." (1954) [Report].
- T. J. Lawton and C. J. Muntz, "Organization of Computation and Control in the Apollo Guidance Computer" (1965) [Report].
- Stuard D. Lenett, "Apollo Digital Up-Data Link Description", NASA Technical Memorandum TM-X-1146.
- Frederick H. Martin and Richard H. Battin, "Computer Controlled Steering of the Apollo Spacecraft" (1967) [Report].
- Frederick H. Martin and Richard H. Battin, "Computer-Controlled Steering of the Apollo Spacecraft," Spacecraft, 5 (1968, 4 Mbytes), 400 - 407.
- J. McNeil, J. E. Miller and J. Sitomer, "Use of Body Mounted Inertial Sensors in an Apollo Guidance, Navigation and Control System" (1966, 4 Mbytes) [Report].
- John E. Miller and Ain Laats, "Apollo Guidance and Control System Flight Experience." (1969) [Report].
- George Mueller, "Final Report: Apollo Guidance Software Task Force" (1968) [Report].
- J. V. Mutchler, "Apollo CMC/LGC Software Development Plan" (1968, 3 Mbytes) [Report].
- J. L. Nevins, "Man-Machine Design for the Apollo Navigation, Guidance and Control System." (1967, 21 Mbytes) [Manuscript].
- J. L. Nevins and I. S. Johnson, "Man-Computer Interface for the Apollo Guidance, Navigation and Control System" (1967, 9 Mbytes) [Report].
- J. L. Nevins, I. S. Johnson and T. B. Sheridan, "Man/Machine Allocation in the Apollo Navigation, Guidance, and Control System" (1968, 24 Mbytes) [Report].
- J. L. Nevins, E. A. Woodin and R. W. Metzinger, "Man-Machine Simulations for the Apollo Navigation, Guidance, and Control System." (1967, 3 Mbytes) [Report].
- James L. Nevins, "Man-Machine Design for the Apollo Navigation, Guidance, and Control System--Revisited: Apollo, A Transition in the Art of Piloting a Vehicle." (1970, 3 Mbytes) [Report].
- Robert N Noyce, "Integrated Circuits in Military Equipment" (1964) [Magazine Article].
- Jayne Partridge, L David Hanley and Eldon C. Hall, "Progress Report on Attainable Reliability of Integrated Circuits for Systems Application" (1964, 5 Mbytes) [Report].
- J. C. Pennypacker, "Whole Number Strapdown Computations" (1966, 3 Mbytes) [Report].
- Daniel Rankin, A Model of the Cost of Software Development for the Apollo Spacecraft Computer (1972, 5 Mbytes) [SM dissertation, MIT].
- Robert T. Savely, Bedford F. Cockrell, and Samual Pines, "Apollo Experience Report—Onboard Navigational and Alignment Software", NASA Technical Note D-6741.
- Norman E. Sears, "Technical Development Status of Apollo Guidance and Navigation" (1964, 3 Mbytes) [Report].
- Edwin D. Smally, "Block II AGC Self-Check and Show-Banksum" (1966) [Report].
- Raymond D. Speer, "Strict Control Kept Out Semiconductor Flaws" (1969) [Magazine Article].
- Madeline M. Sullivan, "Hybrid Simulation of the Apollo Guidance and Navigation System" (1965, 3 Mbytes) [Report].
- B. K. Thomas, "Apollo 8 Proves Value of Onboard Control" (1969, 3 Mbytes) [Magazine Article].
- Milton B. Trageser and David G. Hoag, "Apollo Spacecraft Guidance System" (1965, 25 Mbytes) [Report].
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.
- "LM/AGS Design Survey"
- Just the block diagram of the AEA. (Actually, John had to outlay money for this, as it's not one of Davis's docs, so we have additional cause to thank him. He also tells us it's the best AEA architecture diagram he has seen.)
- Flight Program 8 -- LM AGS FP8 S03 4039, LM Abort Electronics Assembly, 12/18/70, 6325 lines. Complete assembly language listing.
- Scanned assembly listing of AGS Flight Program 8, 185 pages, 28.6M bytes.
- Hyperlinked, colorized HTML assembly listing of AGS Flight Program 8, created by assembling the source code with yaLEMAP, 1.8M bytes. (Same thing as the scanned assembly listing, but much smaller and nicer!)
- LM/AGS Operating Manual, Flight Program 6, 11176-6033-T000, Revision 1, TRW, July 1969, 194 pages, 36.1M bytes.
- LM AGS Computer Program Specification, Flight Program 6, 11176-6042-T000, TRW, March 1969, 90 pages, 14M bytes.
- Memo: Tables and Flow Charts for Preliminary Release of FP8, C. G. Gibson, TRW, 5 January 1971, 2.1M bytes.
- Abort Electronic Assembly Programming Reference, H. L. Stiverson, 7322.3-17, April 1966, 77 pages, 14.6M bytes. This document is the principle (and almost complete) reference for understanding the operation of the AEA CPU per se, the AEA assembly language and assembler, and the operation of the CPU's i/o ports. There are, however, some confusing aspects to the document:
- Perhaps the most confusing thing is that while the portion of the document that covers the LEMAP assembler makes it clear that the integer -1 would be encoded in octal as 0777777 (as anyone working with a modern PC would expect), the portion of the document that covers assembly language repeatedly refers to the octal 0400000 as being "-1". (More specifically, the reference on these occasions is to "A0 = 1, A1 thru A17 = 0", where A0 is the sign bit and A1-A17 are the data bits.) In fact, this octal pattern encodes the "largest" 18-bit negative number, namely -131072. In this detail, the assembly-language portion of the manual is thus incorrect.
- Perhaps the most serious omission is that the explanation of division (the DVP instruction) in the case where the dividend and/or divisor is negative is completely lacking and (in the absence of this explanation) I've never figured out satisfactorily how it is supposed to work
- LM AGS, Programmed Equations Document, Flight Program 6, 11176-6041-T0-00, TRW, 1969 April. Because of the size, we provide this in 2 chunks:
- Body of LM AGS FP6 Programmed Equations document, 220 pages, 46M bytes.
- Appendix A, scanned assembly listing of AGS Flight Program 6, 182 pages, 25.2M bytes.
- Hyperlinked, colorized HTML assembly listing of AGS Flight Program 6, created by assembling the source code with yaLEMAP, 1.6M bytes. (Same thing as the scanned assembly listing, but much smaller and nicer!)
- Program Verification Test Results, LM/AGS Flight Program No. 6, 11176-6050-T000, E. V. Avery, TRW, Redondo Beach CA, May 1969, 49 pages, 13.8M bytes.
- LM AGS Guidance Software, Final Design Report, Flight Program 6, 11176-6052-T0-00, TRW, Redondo Beach CA, April 1969, 10 pages, 1.3M bytes.
- LM AGS Flight Equations, 05952-6076-T000, T. S. Bettwy, TRW, 25 January, 1967, 117 pages, 20M bytes.
- LM/AGS Flight Program 6, LM 5 Mission Constants, 11176-6055-R0-00, C. J. Mabee, TRW, Redondo Beach CA, June 1969, 25 pages, 3.2M bytes.
- LM/Abort Guidance System, Performance and Interface Specifications Document, Preliminary, July 1, 1966, 345 pages (not numbered), 46.2M bytes.
- User's Guide for AGS Bit-by-Bit Simulator, Bulletin 672-21-EAS-208, K. B. Robertson, Lockheed, Houston TX, August 1968, 67 pages, 12M bytes.
- LEM CES and AGS, Grumman, September 1966, 32 pages, 800K bytes. (I think this is available elsewhere on the web, but it's a different scan.)
- "Apollo Experience Report—Guidance and Control Systems: Lunar Module Abort Guidance System" by Pat M. Kurten, NASA Technical Note D-7990.
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.
- Laboratory Maintenance Instructions for LVDC. While the title of this document is undoubtedly correct from the standpoint of IBM (the corporate author), the document is more usefully viewed as a complete explanation of the theory of operation of the LVDC, albeit of a very early breadboard version.
- Volume 1, "General Description and Theory". Topics include a complete description of the computer's instruction set.
- Volume 2, "Maintenance Data". Topics include interfaces to the computer.
- IBM 63-928-137, Saturn V Guidance Computer, Semiannual Progress Report. This sounds like a managerial thing, but is actually is a huge technical document.
- MSFC IV-4-401-1, Astrionic System Handbook, Saturn Launch Vehicles. Chapter 11 is particular relevant to the LVDC, as it discusses the flight software in some detail. Sadly, it does not show any actual sample snippets of LVDC software.
- MTP-ASTR-S-63-15 Saturn IB/V Astrionics System.
- Bellcomm memo, "Memory Requirements for the Launch Vehicle Digital Computer (LVDC)" by J. J. Rocchio.
- Bellcomm memo, "Launch Vehicle Digital Computer (LVDC) Requirements for the Apollo Applications Program" by J. J. Rocchio.
- MSFC III-5-509 Saturn 1B/V Instrument Unit System Description and Component Data:
- -1, "Instrumentation System Description".
- -4, "System Description and Component Data". A scan from collectspace.com.
- NASA Technical Note D-5869, "Description and Performance of the Saturn Launch Vehicle's Navigation, Guidance, and Control System" by Walter Haeussermann.
- Boeing document, "Saturn V Launch Vehicle Guidance Equations, SA-504".
- MTP-AERO-63-64, "An Iterative Guidance Scheme for Ascent to Orbit (Suborbital Start of the Third Stage" by Isaac E. Smith and Emsley T. Deaton, Jr.
- NASA Technical Note D-2967, "Application of an Iterative Guidance Mode to a Lunar Landing" by Helmut J. Horn.
- Here's a set of short documents contributed by Eldon Hall to klabs.org, providing a comparison of the (proposed) AGC to the (proposed) LVDC, and pertaining to the notion of replacing the AGC by the LVDC in the CM and LM. I suppose these documents may be interesting in a historic sense, and in some cases are mildly amusing, but they are interesting to me principally because some of the documents are very rich in technical information about the LVDC.
- "Report on a Technical Comparison of the Apollo Spacecraft Guidance Computer with a Proposed New Design".
- "Guidance Computer for Apollo", a memorandum by David W. Gilbert.
- "Results of Planning Meeting for Apollo Spacecraft Guidance and Navigation Review", a memorandum by David W. Gilbert.
- IBM Apollo Study Report (big downloads):
- Volume 1, #63-928-129, covering the AGC.
- Volume 2, #63-928-130, covering the LVDC.
- "Critique of IBM Apollo Study Report — IBM #63-928-129 — 1 Oct 1963"
- "Problems with IBM Approach as it is Defined in the IBM Apollo Study Report No. 63-928-129" by Eldon C. Hall.
- "Note to Mr. Webb" by R. P. Young.
- "Saturn V / Apollo Spacecraft Guidance Computer Development Programs", a memo by General Phillips.
- "Saturn V / Apollo Spacecraft Guidance Computer Conference", a memo by General Phillips.
- "Saturn V Guidance Computer for Use as Apollo Back Computer", a memo by Joe Shea.
- MSFC-MAN-206, Skylab Saturn IB Flight Manual.
- MSFC-MAN-503, Saturn Flight Manual, SA-503.
- S&E-ASTR-S-101-69, Technical Information Summary, Apollo-11 (AS-506).
- MSFC-MAN-507, Saturn V Flight Manual, SA-507.
- NASA Technical Memorandum X-53384, "The Astrionics System of Saturn Launch Vehicles" by Rudolf Decher.
- IBM Saturn Instrument Unit Fact Sheet.
- NASA Technical Memorandum X-53350, "Saturn Instrument Unit Command System" by H. R. Lowery.
- NASA Technical Note TN D-4481, "Saturn V Manual Backup Guidance and Control Piloted Simulation Study".
- NASA Technical Memorandum, "Report on Digital Computers Used in Automatic Checkout" by B. Funderburk.
- NASA Technical Memorandum X-53274, "Techniques of Implementing Launch Automation Programs (Saturn IB Space Vehicle System)" by William G. Bodie.
- NASA Technical Memorandum X-53398, "Saturn I Block II Guidance Summary Report" by R. A. Chapman.
- TR-612, Saturn IB and Saturn V Computer Programs, Software Status Report.
- NASA SP-4206, Stages to Saturn by Roger E. Bilstein. This is actually a book in the NASA History Series, so it isn't as technical, but is full of all sorts of contextual detail that is missing from the technical documents.
RCA 110A (Saturn ground computer) Mathematical Subroutine Manual. Dimitri Marinakis (thanks Dimitri!) sent me this. The ground computer which which the LVDC cooperated was an RCA 110A. "Mathematical Subroutine Manual" sounds very exciting until you find that it means "multiplication", "division", "cosine", "sine", etc. It is still an interesting document, in the sense that it reveals what life was like for the computer programmer in that time-frame. These algorithms are each accompanied by RCA 110A assembly language showing exactly how they were implemented, and give the full theory for each method, duly written up as if the description was a mechanical drawing, with a proper page border appropriate to such a drawing, and accompanied by notations such as the units, scale, and tolerance of the drawing! I've chosen to provide it only as a tarball of JPEG page images rather than to convert it to a PDF (which would take twice the storage), and I hope nobody minds that. The image at right (supplied by Dimitris Vitoris) is a photo of an unknown (to me) assembly from an RCA-110A.
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.)
- Skylab Command Service Module Systems Handbook, CSM 116-119 (Apollo Skylab 2-4.)
Operations Handbooks
- Apollo Operations Handbook, Command and Service Module, Spacecraft 012. (This was the Block 1 spacecraft for Apollo 1.)
- Apollo Operations Handbook, Block II Spacecraft:
- Volume 1:
- Chapter 1: Spacecraft
- Chapter 2: Systems Data
- 2.1. Guidance and Control
- 2.2. Guidance and Navigation System (G&N)
- 2.3. Stabilization and Control System (SCS)
- 2.4. Service Propulsion System (SPS)
- 2.5. reaction Control System (RCS)
- 2.6. Electrical Power System
- 2.7. Environmental Control System (ECS)
- 2.8. Telecommunications System
- 2.9. Sequential Systems
- 2.10. Caution and Warning system
- 2.11. Miscellaneous Systems Data
- 2.12. Crew Personal Equipment
- 2.13. Docking and Transfer
- Chapter 3: Controls and Displays
- Abbreviations and Index
- Alternate excerpts. (Contributed by Fabrizio Bernardini.)
- Sections 2.1-2.2. (40 pages, 2.5M bytes.)
- Sections 4.6-4.8. (112 pages, 2.2M bytes.)
- LMA790-3-LM, Apollo Operations Handbook, Lunar Module:
- Volume 1 (LM 10 and subsequent), "Subsystems Data"
- Volume 2 (LM 11 and subsequent), "Operational Procedures"
- Alternate excerpts. (Contributed by Fabrizio Bernardini.)
- Excerpts from Section 2.1. (81 pages, 4.8M bytes.)
- Excerpts from Section 4.4. (66 pages, 1.8M bytes.)
- Lighting tables. (2 pages, 2.1M bytes.) Tables from the ops handbook describing colors, brightnesses, etc., for the Apollo spacecraft interior and exterior lighting. (Contributed by Paul Fjeld.)
Operational Data Books
- "G", "H", and "J" missions: CSM/LM Spacecraft Operational Data Book:
- Volume 3, "Mass Properties".
Technical Crew Debriefings
- Apollo 8 Technical Crew Debriefing: First half and second half. (Contributed by original AGC developer Fred Martin.)
- Apollo 11 Technical Crew Debriefing: Volume 1 and Volume 2.
- Apollo 15 Technical Crew Debriefing.
- Apollo 17 Technical Crew Debriefing.
Mission Reports
- Apollo 10
- Supplement 2, "Guidance, Navigation, and Control Systems Performance Analysis"
Flight Plans
- Apollo 8 Flight Plan: Sections 1 and 2 and sections 3 through 5. (Contributed by original AGC developer Fred Martin.)
- Apollo 9 Flight Plan
- Apollo 11 Flight Plan
- Apollo 12 Flight Plan
- Apollo 15 Flight Plan
- Apollo 16 Flight Plan
- Apollo 17 Flight Plan
Checklists
- Apollo 15:
Familiarization Manuals
- LMA790-1, "Lunar Excursion Module Familiarization Manual"
- LMA790-2, "Lunar Module LM-10 Through LM-14 Vehicle Familiarization Manual"
General Apollo documents unrelated to computing systems
Press Kits and Releases
- Apollo 7 press kit
- Apollo 8
- Press release 68-208, "First Manned Lunar Orbit Mission".
- Apollo 9 press kit
- Apollo 10 press kit
- Apollo 11
- Apollo 12 press kit
- Apollo 13 press kit
- Apollo 14 press kit
- Apollo 15 press kit
- Apollo 16 press kit
- Apollo 17 press kit
- Apollo-Soyuz Test Project (ASTP)
Miscellaneous
- MG-402, "Handbook for Apollo Instrumentation Ships".
- CD42-A/SL-997, "Handbook of Pilot Operational Equipment for Manned Space Flight".
Gemini spacecraft computer
- Project Gemini Familiarization Manual, contributed by Adam Bootle to the Meadville Space Center website. As far as the onboard computer is concerned, it is Section VIII that is relevant. This describes (among other things), the on-board computer architecture, memory layout, and CPU instruction-set. The links at Meadville indicate that Volume 1 is for spacecraft GT-3, GT-4, and GT-7, while Volume 2 is for GT-5, GT-6, and GT-8 through GT-12. If you are only going to look at one of them, look at Volume 2 Section VIII.
- Volume 1 (except Section VIII), "Long Range and Modified Configurations"
- Volume 1, Section VIII, "Guidance and Control Systems"
- Volume 2 (except Section VIII), "Rendezvous and Docking Configurations"
- Volume 2, Section VIII, "Guidance and Control Systems". I've actually improved this document somewhat by removing about thirty duplicated (and very confusing, too!) pages, and to add a bookmark pane that makes it much easier to navigate around in the document.
- "Abbreviated Summary of Gemini Software History", a short memo about the versioning of Gemini OBC software, up and including GT-10. (Provided by Dick Jasinski via Gene Mertz.)
- OBC presentation slides (?), giving a summary of the OBC, it's software, and peripherals in 80 pages ... possibly for astronaut training.
- "Gemini Programming Manual". This unique and document was written by original Gemini programmers Charlie Leist and Jim Condell, and describes programming the on-board computer from the programmers' perspectives; as such, it discusses various pragmatic difficulties rather than just the theoretical ideal, though it also covers the on-board computer's CPU instruction set and similar topics in a way that both overlaps and differs from the "Guidance and Control Systems" documents listed in the item above. Charlie has additionally (in 2011) thoughtfully recreated a missing document page for us. It's a big download (49MB for 35 pages) because I didn't have the heart to reduce the resolution of the scan, but it's indispensible if you're interested in the on-board computer software.
- Detailed Math Flow diagrams. (I.e., very detailed flowcharts of the software design for the flight software.)
- Complete Math Flow from 1963 (prior to ATM), with Alden Minnick's handwritten notes. (The illegible notes at the left margin of p. 17 are: "TE = AT LIFT OFF T" and "TE > TE0 = LIFT OFF".)
- Ascent & Fast Ascent only, from 1963. See pp. 2-3 of the linked document. The document (actually, Appendix E) contains a lot of other helpful stuff like detailed explanations of the variables, some additional theory, and source code of a FORTRAN implementation. I'm not really clear where this goes in the development chronology, merely that it is a few months later than the corresponding elements from the Detailed Math Flow in the preceding entry. The Appendix comes from the following report, of which we don't have an electronic version at present, but may be able to provide one in the future: "Preliminary Ascent Guidance Simulation Report (Analytic Report No. 6)", IBM No. 63-564-0159, 31 January 1963, by D.P. Bedford, R.E. Cofer, T.W. Hill, R.B. Jasinski, J. Park, J.R. Sims, R.V. Wadding.
- Module III only (Catch-up & Rendezvous) from 1966 (post ATM)
- "Gemini Catch-Up and Rendezvous Analysis and Simulation Report #4", contributed by Gene Mertz and scanned by Dave Mertz. This "report" actually contains the full source code for the mixed FORTRAN II and IBM 7090/7094 assembly language program that was used to verify algorithms and simulate flight-computer behavior for the Catch-Up and Rendezvous flight phases. Therefore, although it is not flight software per se, it is presently the closest thing we have to Gemini flight software. There are also 5 fold-out flowcharts which are split into multiple pages in the PDF, which I've pulled out, deskewed, rescaled, and rejoined. They're not perfect, but they're a little easier to read than the pages in the PDF file:
- "Geophysical Constants for Use in Gemini". Contributed by OBC developer P. J. Holcombe (c/o Gene Mertz). Some of the constants listed no longer agree with current values, but they're what were used at the time. According to our best understanding at present, the symbol Φ is the gravitational potential. Gene adds that he thinks that "the angle, phi (f) in the three-term expansion of the earth's oblate geo-gravity model, is measured from the ascending node of a Gemini orbit rather than latitude."
- "Writeup of Problem 6056 — 26 Bit Orbit Calculation", a 1962 hand-written memo, presumably by Gene Mertz, regarding issues such as roundoff and step size in the Gemini orbital calculation.
- Gemini orbit rate compensation note, handwritten by Gene Mertz.
- "Summary of Fixed Point Orbital Navigation Using Modified Euler Integration and a Two Term Potential Function", memo by Gene Mertz. (There are some hand-drawn corrections on the first page that may be hard to read. In two places it say "t+h", and later in the same paragraph, the y in "y=f(t)" has been dotted.)
- Here are some supplemental non-Gemini documents (mostly from the Computer History Museum) which may be of assistance in understanding the FORTRAN dialect, the assembly language, and the operating system under which the simulation program from Report #4 above ran. At any rate, I found them useful in porting the code to make it portable to more up-to-date computers.
- FORTRAN ASSEMBLY PROGRAM (FAP) for the IBM 709/7090
- Reference Manual: FORTRAN II for the IBM 704 Data Processing System
- Programmers' Reference Manual: Fortran Automatic Coding System for the IBM 704
- General Information Manual: Programmer's Primer for FORTRAN Automatic Coding System for the IBM 704 Data Processing System
- The Compatible Time-Sharing System: A Programmer's Guide
- IBM 704 Electronic Data-Processing Machine Manual of Operation
- Portions of IBM 709 Data Processing System Reference Manual and FORTRAN Automatic Coding System for the IBM 709. Includes an assembly-language manual.
- Systems Manual for IBM 704 and 709 FORTRAN. Explains magnetic-tape operations.
- Jack Harper's web-page provides a useful alternate source of information on IBM 7090/7094 assembly language and related issues.
- Gemini Operations Handbook
- Spacecraft 7, Sections 2.5.2-2.5.7. This is something like a user manual for the Gemini computer. Contributed by Dr. Lance Erickson to Meadville.
- Spacecraft 10, Sections 3.8.1. This is the command set for the Agena target vehicle (ATV), and nothing to do with the Gemini computer per se. Contributed by John Bisney to Meadville.
- Gemini Mission Reports:
- Analyses:
- Gemini V Supplemental Report 6, "Inertial Guidance System and Computer Analysis".
- Gemini 7/6 Supplemental Report 5, "Gemini GT-6A Post Flight Analysis Report, Gemini GT-6 Rendezvous and Catch-Up Post Flight Report, and GT-7/6 Re-Entry Mission Reconstruction Report". These reports contain various reconstructed positioning data.
- "GT-9 Post Flight Analysis Report Supplement". This document contains reconstructed ascent and re-entry positioning data.
- "GT-12 Post Flight Analysis Report". This document contains reconstructed rendezvous positioning data.
- Miscellaneous:
- Gemini VIII Flight Plan
- Gemini XI Press Kit
- Project Gemini technology and operations - A chronology, from the NASA Historical Series.
from http://www.ibiblio.org/apollo/links.html