.
Various presentations presented at the MAPLD '04 conference, by
AGC developers and other knowledgeable folks
This section pertains to a document (E-2448) called "Users' Guide to Apollo GN&CS Major Modes and Routines", presented in several different revisions. While the document itself purports to be general purpose in nature rather than mission-specific, it was nevertheless maintained to remain current, and therefore can be roughly matched (from publication dates and internal information) particularly-relevant missions.
Regarding the Block II AGC schematics, I have heard that there is
a general attitude that they are incomplete, which is true, and
therefore inadequate for allowing one to construct a hardware
simulation of a Block II AGC, which is probably not true.
Mike Stewart, who has in fact built such a hardware simulation,
assesses the adequacy as follows (in slightly edited form):
[It depends] on what is meant by "complete". The logic and interface modules are all present, so working simulations/replicas of the *logic* of the computer, and its connections to the outside world, are certainly possible ...
That being said, there are missing pages, which make it more difficult (and less accurate/"complete") than it needs to be. All of them are in Tray B and the DSKY. [There is only one schematic page] for each -- the clock oscillator in Tray B, and the power supply for the DSKY (D7).
The missing modules are, to my knowledge:
- Analog Alarms Module (B8):
- Filtering for the AGC warning light (the three possible causes of this light were OR'd together in Tray A, then shipped here for "filtering", but I don't know what that entails)
- Voltage monitoring (announced through VFAIL)
- Oscillator monitoring (announced through OSCAL)
- Scaler module monitoring (announced through SCAFAL/2FSFAL)
- A start-up/restart signal whose exact cause I haven't yet identified (STRT2), but probably has to do with voltage stability
- Erasable Driver Module (B9-B10):
- Exactly as it sounds, took the signals generated mostly by modules A14 and A15 and drove the core memory accordingly
- Current Switch Module (B11):
- This is probably used for driving the various currents needed by the Erasable memory. In that capacity, I assume it would receive some or all of the signals ZID, SETEK, RSTKX/, RSTKY/, REX, REY, WEX, and/or WEY, while the Erasable Driver Module handles core selection with XT0E-XT7E, XB0E-XB7E, YT0E-YT7E, and YB0E-YB3E. Or maybe the Erasable Driver Module gets all of those, and has its own set of inputs to the Current Switch Module. Or vice-versa! It's bound to be something along those lines, at least.
- Module B12:
- If that's even a thing. There's a weird wiry-looking thing between modules B11 and B13 on Tray B.
- Sense Amplifier Module (B13-B14):
- Sense signals from memory, one each for fixed and erasable, and put them out on the sense amplifier lines to fill the G register. Interestingly, we've got drawings (maybe even labelled with values somewhere) of the chips used on this board, but not the board itself.
- Strand Select Module (B15):
- Rope driving stuff, although I don't know why it's separate from the Rope Driver module
- Rope Driver Module (B16-B17):
- The main rope drivers. Take signals from A14, A15, and... A6 I think? and drive the ropes
- Indicator Driver Module (D1-D6):
- Contained DSKY relay driver circuits and the relays themselves
Plus, any other ancillary information that wasn't done on a circuit board like DSKY button wiring, pinouts, backplane connections, and such that I can't put a number or name to.
I'd argue that none of this is strictly necessary for a "complete" simulation. Nobody's going to weave their own core/core rope memory anyways... there's tons of ferrite cores on ebay. I did the math. It would take years. So that immediately drops the need for B9-10 and B13-17. It's possible to implement your own versions that respond only to the signals fed directly to those modules (ie without cheating), which is how mine works. ...
The alarms module stuff can be done custom to the application, or without the filter (FLTIN connected straight to FLTOUT), or whatever.
There are enough partial drawings of the indicator driver module that you can cobble something reasonably close to the real thing together, albeit with probably different relay decoding wiring (though there's less correct answers to this than many seem to think) and component values.
THAT BEING SAID, as somebody trying to build a replica that's as accurate as possible, all of these and any other electrical/mechanical drawings are now at the top of my want-list.
This is a series of memos from the MIT Instrumentation Lab dealing with issues of Luminary software development. Of particular interest, if you're concerned with the evolution of the AGC software, many of them memos are used to document the changes of the Luminary code from one revision to the next. In theory, if you had all of them, you could use them to document the complete evolution of Luminary, or at any rate from LUMINARY 4 (memo #22) through LUMINARY 209 (memo #205). Some of the gaps can also be filled in with SCB meeting reports, in the next section.
There are over 250 known LUMINARY Memos, of which we have (or are in the process of obtaining) the majority from Don Eyles's personal collection. Here at the Virtual AGC site we are providing these memos in a convenient, readable quality, but higher-quality archival versions are available in our Virtual AGC collection at the Internet Archive. In the table below, the lines which are grayed-out are not in Don's collection at all.
There is an equivalent series of COLOSSUS and DANCE (SUNDANCE) development memos, and probably others as well, but we have none of them except where they happen to coincide with LUMINARY memos.
LUMINARY Memo #
COLOSSUS or (SUN)DANCE Memo #
Date
Author
Subject
1
DANCE 2
11/7/67
J. Rhode
2
DANCE 7
11/15/67
Steve Copps
Tiger Team
3
DANCE 8
11/13/67
George Cherry
Minutes of MSC LM Digital Autopilot Design Review
4
11/29/67
George Cherry
5
DANCE 14
11/27/67
J. Saponaro
Synchronization of W-Matix and State Vector
6
1/12/68
George Cherry
7
1/16/68
George Cherry
LUMINARY GSOP Chapter 5 and Chapter 4 Review
8
DANCE 34
1/24/68
John Vella
Recent Changes to PINBALL Affecting DSKY Operation
9
COLOSSUS ?
2/6/68
A. Martorano
Minutes of PRC Meeting 2 February 1968
10
DANCE 37
2/9/68
George Cherry
RCS Jet Firings During Gyro Torquing in P52 on SUNDANCE
11
DANCE 38
2/12/68
J. S. Miller
Inhibition of DAP Operation in SUNDANCE and LUMINARY
12
DANCE 40
2/13/68
S. Davis
Hybrid Facility Procedures
13
DANCE 45
2/26/68
George Cherry
Deadband Setting PCR #86
14
DANCE 48
3/4/68
Alex Kosmala
Key Release Light
15
3/8/68
N. Neville
SETUP504
16
COLOSSUS 41
3/14/68
Alex Kosmala
ABORT
17
DANCE 51
COLOSSUS 423/15/68
J. Saponaro
AGC Time Dependent Constants
18
3/?/68
R. Tinkham
LUMINARY Downlist
19
3/4/68
Allan Klumpp
20
DANCE 57
4/1/68
Jim Kernan
SUNDANCE Revisions 280, 281 and 282 and LUMINARY Revision 0
21
4/8/68
Craig Schulenberg
LUMINARY Revisions 1, 2 and 3
22
4/15/68
Craig Schulenberg
23
4/22/68
Craig Schulenberg
24
DANCE 69
4/24/68
C. Braunhardt
25
4/30/68
Craig Schulenberg
26
COLOSSUS 26
5/13/68
Don Eyles
27
5/10/68
Allan Klumpp
28
5/14/68
Craig Schulenberg
29
6/6/68
Craig Schulenberg
30
6/7/68
Jim Kernan & Schulenberg
31
6/12/68
Craig Schulenberg
32
6/24/68
Peter Weissman
33
6/24/68
George Cherry
34
7/15/68
Craig Schulenberg
35
7/30/68
George Cherry
36
DANCE 83
7/30/68
George Cherry
Computing the Lag Angles which Prevent Beginning and Supervised DAP Maneuvers
37
8/5/68
Craig Schulenberg
LUMINARY Revisions 35 - 38
38
DANCE 84
8/6/68
Craig Work
Restrictions to R03 (Verb 48) Inputs
39
8/27/68
George Cherry
Scheduling Proposed Modifications to the LUMINARY Digital Autopilot
40
9/5/68
Craig Schulenberg
41
8/28/68
A. Laats & J. Shillingford
LUMINARY Level 3 Verification Plan
42
9/12/68
George Cherry
43
9/16/68
George Cherry
44
9/19/68
Don Eyles
45
9/24/68
Don Eyles
46
10/15/68
George Cherry
LUMINARY Level IV Test Data Requirements for Pre-FACI Review
47
10/29/68
George Cherry
48
10/24/68
J. Connor
49
11/1/68
Craig Schulenberg
50
11/2/68
Craig Schulenberg
51
11/2/68
Craig Schulenberg
52
11/3/68
Craig Schulenberg
53
11/12/68
George Cherry
54
11/18/68
George Cherry
55
12/4/68
Craig Schulenberg
56
DANCE 86
12/4/68
George Cherry
57
12/9/68
George Cherry
58
12/17/68
Craig Schulenberg
59
DANCE 87
1/3/69
Craig Work
SUNDANCE Edits for DAP and for Powered Descent
60
1/9/69
Jim Kernan, Peter Volante
61
1/14/69
Craig Schulenberg
62
1/24/69
George Cherry
63
1/27/69
George Cherry
A Derivation of the Improved Lunar Landing Guidance Equations
64
2/4/69
Jim Kernan
65
2/7/69
George Cherry
66
2/12/69
George Cherry
Aborts from the Lunar Landing & Nominal Lunar Ascent Targetting
67
2/17/69
Craig Schulenberg
68
2/20/69
George Cherry
69
3/10/69
Craig Work
70
COLOSSUS 163
3/13/69
Joe Saponaro
Accuracy of Verb 83 (Range, Range Rate, Theta Display)
71
3/14/69
Peter Volante
72
COLOSSUS 167
Bill Ostanek
Use of V96 During State Vector / W Matrix Synchronization
73
3/27/69
Craig Schulenberg
74
3/31/69
Peter Adler
75
4/1/69
George Cherry
76
4/1/69
Don Eyles
77
4/3/69
George Cherry
78
4/10/69
Craig Schulenberg
79
COLOSSUS 171
4/15/69
Jane Goode
Computation Cycle Timing in TPI, TPM Programs
80
4/24/69
Don Eyles
81
4/28/69
Don Eyles
82
5/8/69
J.E. Jones
83
5/19/69
Jim Kernan
84
5/21/69
Don Eyles
85
5/21/69
Jim Kernan
86
COLOSSUS 183
5/21/69
Eugene Muller, Peter Kachmar
Affect of Radar (or the HF Ranging) AGC Interface Problem on F Mission Rendezvous Sequence
87
5/28/69
George Cherry
George Lowe's Decision at CCB Regarding LGC Radar Interface Problem
88
6/5/69
Don Eyles
89
6/23/69
Peter Adler, Dana Densmore
90
COLOSSUS 191
6/30/69
Jenny Flaherty
Memo Indexes
91
7/7/69
Craig Schulenberg
92
7/10/69
Craig Schulenberg
93
7/14/69
J.E. Jones
94
7/14/69
Bruce McCoy
95
7/9/69
Robert Covelli
96
7/14/69
Bruce McCoy
97
7/16/69
Don Eyles
98
COLOSSUS 198
7/22/69
Margaret Hamilton
Review of Reduction of Coding Approval Procedures
99
7/23/69
George Cherry
100
7/31/69
Craig Schulenberg
101
8/4/69
Bruce McCoy, George Cherry
102
8/6/69
George Cherry (attached is 8/4 Eyles/Cherry PCR 854)
Some Results of the Apollo 12 Pinpoint Lunar Landing Data Priority Meeting
103
8/6/69
Craig Schulenberg
104
8/8/69
David Moore, Don Eyles
105
COLOSSUS 209
8/14/69
Al Engel, Bruce McCoy
H Mission RTCC Compatibility Testing, Test Plan & Schedule (Preliminary)
106
COLOSSUS 210
8/14/69
Al Engel, Bruce McCoy
RTCC Compatibility Testing at MIT, Current Understanding of Scope, Responsibilities, etc.
107
8/20/69
Craig Schulenberg
108
8/22/69
Bruce McCoy
109
9/9/69
Bruce McCoy
110
COLOSSUS 213
9/10/69
Bill Ostanek
Bad Other Vehicle State Vector
111
9/19/69
Bruce McCoy
112
9/22/69
M. Albert
113
COLOSSUS 218
10/2/69
S. David
Configuration Control of RTCC Digital Environment
114
10/7/69
Russ Larson
115
10/9/69
Don Eyles
116
10/22/69
Larry Berman
117
10/24/69
George Kalan
Special Crew Procedures Necessary for Controlling the CSM-Docked Configuration with the LEM DAP
118
10/27/69
Don Eyles
119
10/30/69
Harry McOuat
120
11/5/69
Russ Larson
121
11/5/69
Bruce McCoy
122
11/6/69
Dana Densmore
123
11/18/69
Don Eyles
124
11/11/69
Dana Densmore
125
COLOSSUS 232
11/21/69
D. Reinke
Work-around for P32 Bomb-Outs
126
12/2/69
Don Eyles
127
12/3/69
Bruce McCoy
128
12/3/69
Bruce McCoy
129
12/5/69
Dana Densmore
130
12/15/69
Russ Larson
131
1/2/70
Dana Densmore
132
COLOSSUS 240
1/8/70
Ken Greene
133
1/9/70
Peter Volanta, G. Dunbar
134
1/19/70
Dana Densmore
135
1/23/70
Robert Covelli
Downrupt Losses During Periods of High Computer Activity Programs
136
1/29/70
Dana Densmore
137
1/30/70
Russ Larson
138
2/14/70
Don Eyles
139
3/3/70
Don Eyles
140
3/4/70
Allan Klumpp
141
3/10/70
Larry Berman
142
3/18/70
Dana Densmore
143
3/24/70
Allan Klumpp
144
4/6/70
Don Eyles
145
5/5/70
Dana Densmore
146
5/?/70
Robert Covelli
The New R12
147
5/5/70
Allan Klumpp, Don Eyles, Bruce McCoy
148
5/11/70
Bruce McCoy
149
5/13/70
Don Eyles
150
5/15/70
Dana Densmore
151
5/19/70
Dana Densmore
152
5/21/70
Don Eyles
153
5/26/70
Sharon Albert
154
6/1/70
Larry Berman
155
6/1/70
Bruce McCoy
156
6/9/70
Dana Densmore
157
6/10/70
Dana Densmore
158
6/18/70
Bruce McCoy, Dana Densmore
159
7/10/70
Russ Larson
160
7/16/70
David Moore
161
7/17/70
Don Eyles
162
7/20/70
Don Eyles
163
7/21/70
Don Eyles
164
7/22/70
Phyllis Rye, Peter Peck
165
7/28/70
Don Eyles
166
7/23/70
David Moore
167
8/17/70
Bruce McCoy, Phyllis Rye
167 (rev 1)
9/17/70
Bruce McCoy, Phyllis Rye
168
8/18/70
Robert Covelli
169
9/1/70
Harry McOuat
170
9/15/70
Bruce McCoy
171
9/16/70
Don Eyles
172
10/11/70
Dana Densmore
173
10/12/70
Dana Densmore
174
COLOSSUS 293
10/9/70
Bill Robertson
175
10/13/70
Dana Densmore
176
10/14/70
Dana Densmore
177
10/22/70
Don Eyles
178
10/20/70
Peter Weissman
179
10/27/70
Dana Densmore
180
12/15/70
David Moore
181
12/15/70
Don Millard
182
12/8/70
Dana Densmore
183
12/9/70
Dana Densmore
184
12/15/70
Dana Densmore
185
12/17/70
Dana Densmore
186
12/22/70
David Moore
187
12/18/70
Dana Densmore
188
12/20/70
Dana Densmore
189
12/28/70
Dana Densmore
190
12/29/70
Dana Densmore
191
1/4/71
Harry McOuat
192
1/5/71
Dana Densmore
193
1/8/71
Dana Densmore
194
1/22/71
Allan Klumpp
195
1/11/71
Dana Densmore
196
1/13/71
Dana Densmore
197
1/15/71
Dana Densmore
198
1/29/71
Craig Work, Peter Weissman
199
2/12/71
David Moore
P99 — Erasable Memory Program for a Guided RCS Burn — Luminary 1E
200
2/22/71
V. Dunbar, Peter Volante
Implementation and Testing of PCR 324, PGNCS/AGS RR Data Transfer
201
COLOSSUS 310
2/16/71
Dana Densmore
DOWNRUPT SEQUENCING, LOST DOWNRUPTS, AND IMPAIRED DOWNLINK INFORMATION
202
2/16/71
Dana Densmore
203
2/23/71
Craig Work, Peter Weissman
204
2/24/71
Dana Densmore
205
2/26/71
Dana Densmore
206
3/9/71
Peter Weissman
207
3/17/71
David Moore
208
3/16/71
Allan Klumpp
209
3/23/71
Peter Weissman
Update to Luminary Memo 178, "Inputs to LM DAP During Descent and Ascent"
210
COLOSSUS 312
3/23/71
Peter Volante, Bill Ostanek
211 (rev 1)
4/28/71
David Moore
"Erasable Memory Program" for a guided RCS burn (for Luminary 1E)
212
3/29/71
Larry Berman
213
3/31/71
Craig Work
214 (rev 1)
4/6/71
Luminary Test Group
215
COLOSSUS 316
4/20/71
William Robertson
Limitations in the Astrodynamic Orientation and Ephemeris Routines
216
4/23/71
Craig Schulenberg, Peter Weissman
Impact of PCR 1107 (Abort Bit Backup) on Apollo 15 Abort Procedures
217
5/6/71
Russ Larson
218
5/19/71
David Moore
219
5/26/71
Craig Schulenberg
220
6/4/71
Craig Schulenberg
Erasable Memory Program for LUMINARY Rev. 210 to Provide Backup for DSKY Keys
221
7/12/71
Craig Work
222
6/15/71
Luminary Test Group
223
6/17/71
Craig Schulenberg
224
6/22/71
Craig Schulenberg, Phyllis Rye
Revision 1 of Erasable Memory Program for Backup for DSKY Keys
225
7/8/71
Peter Volante
226
227
7/13/71
Luminary Test Group
Level 6 Test of DSKY Keystroke Backup Erasable Progeram for LUMINARY 1E
228
7/21/71
David Moore, Peter Volante
Using P99 LM Deorbit Erasable Program in Earth Orbit (with full DPS/APS configuration)
229
7/15/71
David Moore, Craig Work, Peter Weissman
230
9/10/71
Larry Berman
231
11/8/71
Don Millard
232
11/16/71
Don Eyles
233
COLOSSUS
11/23/71
Margaret Hamilton
234
COLOSSUS
11/30/71
Bruce McCoy, Don Millard
235 (rev 1)
2/22/72
Don Eyles
236
12/23/71
Larry Berman
Crew Corrections for Cross Range Error due to Uncompensated Orbit Precession
237
238
239
2/22/72
Don Eyles
240
3/2/72
Luminary Test Group
24X
4/14/72
Don Eyles
Latest EMP 103B
241
242
243
244
4/18/72
Don Eyles
245
246
247
9/1/72
Don Millard
248
249
250
10/20/72
Luminary Test Group
251
252
11/20/72
Don Eyles
≥ 253
The Software Control Board (or perhaps Software Change Board, or
perhaps Software Configuration Board, I'm not really sure, but
does it really make a difference?) meetings were meetings held
between the MIT Instrumentation Lab and the Manned Spacecraft
Center, and I presume other parties as needed, to approve or
disapprove PCRs (Program Change Requests) and PCNs (Program Change
Notices), as well as to report the closure of such items. As
such, they can serve (for our purposes) to fill in gaps in
LUMINARY Memo or COLOSSUS Memo series in order to track AGC
revision-to-revision changes. We don't have many of these,
but Don Eyles has given us a few in order to help understand some
of the changes in Luminary 131 for Apollo 13 that weren't tracked
by the LUMINARY Memos.
These items are alphabetical by author, though the "author" is sometimes an organization when no individual authors are listed. A lot of the documents in this group originally came from the now-defunct AGC website of MIT's Dibner Institute for the History of Recent Science and Technology; but whenever the opportunity has arisen, those versions of the documents have been replaced by better scans, so even when the document titles are the same, these may not be the same scans found in other online sources.
The document was prepared while I was working for Al Hopkins and Ray Alonso at the Instrumentation Laboratory and describes the analysis of the crux of a proposed backup system if the AGC became overloaded during the LEM trajectory. Although the backup method described was never used, the document shows the type of analysis that went on "behind the scenes" in support of the entire mission.
Note that this section doesn't include things like GSOP
documents, which have their own section above, but is simply a
catch-all for everything I haven't already listed that's mission
specific or specific to a mission class.
Max Faget was a fanatical advocate of the optical tracker as the primary rendezvous navigation sensor. If he had had his way there would have been no rendezvous radar. This was an undocumented chapter in the Apollo program known to those of us who participated as the Rendezvous Wars. Under our tutelage, supported by extensive in-house Monte-Carlo analyses, the Astronaut Office took an uncompromising position on behalf of the radar as the primary rendezvous navigation system.
The wars continued into the Shuttle program, and were lost by our side because the FOD was able to make the case that they could support all rendezvous operations with ground-based tracking, and there was therefore no argument for autonomous on-board capability. Max got his way on the Shuttle, there was no rendezvous radar. By that time I was back in Houston working for a small company under contract to MPAD for orbital operations analysis. I got fired for refusing to lie to Draper about the availability of reference mission data to support some independent analysis they were doing for my former colleagues in SED. Thus ended my involvement in the wars, and I've always treasured those memories.
This document contains nomographs for computing the TPI and M/C maneuvers using LM boresight elevation angle measurements, and raw rendezvous radar data from the tape-meter readout. During the months prior to Apollo 11, I was able to use the GN&C analysis program in Monte-Carlo mode to construct computation tables for the CDH and CSI burns. This was done by perturbing the trajectory about the nominal, and developing power-series expansion functions for the maneuvers in terms of the resulting radar range and range-rate perturbations, obtained from measurements at fixed intervals before each burn. We wanted to be able to verify the on-board maneuver solutions independently of the ground, or in extremis do without them altogether, and still carry out the rendezvous as long as we had an operating radar. Hence our fanatical determination to have the radar as the primary rendezvous sensor.
I'm not sure these nomographic and tabular backups were known to the Instrumentation Lab. They were brute force, but they worked. Never needed, though; the IL software and systems were iron-bottomed and gold-plated... [ellipsis Clark's]
- R-649, "The Apollo Rendezvous Navigation Filter Theory, Description and Performance", Volume 1 of 2, by Eugene S. Muller, Jr., and Peter M. Cachmar, June 1970
- "Crew Procedures Orbital Guidance and Navigation Program, Navigation Section"
In this section, we provide some stuff that doesn't directly
pertain to any of the computers in Apollo or Gemini. But if
the original developers give me interesting and sometimes unique
material, or if I find interesting material related to them, I'd
like to present it anyway.
