Source Code

These source-code files were transcribed from scans made from Don Eyles's personal copy of Luminary 069. They were scanned at archive.org's Boston facility, and the scanning was sponsored by Onno Hommes. The code was transcribed from these scans by a team of volunteers who are referenced in the program comments. Comments from the original source code are prefixed with a single '#' symbol, whereas comments added later are prefixed by "##" or "###". In some cases, where similar code blocks exist in previously-transcribed AGC programs (primarily Luminary 99, from Apollo 11) those code blocks were used as a starting point and then corrected to agree with the Luminary 69 scans. The full scans are available at the Virtual AGC project's collection at archive.org, while more-convenient reduced-size (but reduced-quality) images are available at the main Virtual AGC website. Report any errors noted by creating an issue report at the Virtual AGC project's GitHub repository. Notations on the program listing read, in part:

	GAP:  ASSEMBLE REVISION 069 OF AGC PROGRAM LUMINARY BY NASA 2021112-011
	19:02 NOV. 25,1968
Note that the date is the date of the printout, not the date of the program revision.

014515,000002:                                                                                                  ## Copyright:   Public domain.
014516,000003:                                                                                                  ## Filename:    LEM_GEOMETRY.agc
014517,000004:                                                                                                  ## Purpose:     The main source file for Luminary revision 069.
014518,000005:                                                                                                  ##              It is part of the source code for the original release
014519,000006:                                                                                                  ##              of the flight software for the Lunar Module's (LM) Apollo
014520,000007:                                                                                                  ##              Guidance Computer (AGC) for Apollo 10. The actual flown
014521,000008:                                                                                                  ##              version was Luminary 69 revision 2, which included a
014522,000009:                                                                                                  ##              newer lunar gravity model and only affected module 2.
014523,000010:                                                                                                  ##              This file is intended to be a faithful transcription, except
014524,000011:                                                                                                  ##              that the code format has been changed to conform to the
014525,000012:                                                                                                  ##              requirements of the yaYUL assembler rather than the
014526,000013:                                                                                                  ##              original YUL assembler.
014527,000014:                                                                                                  ## Reference:   pp. 334-338
014528,000015:                                                                                                  ## Assembler:   yaYUL
014529,000016:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
014530,000017:                                                                                                  ## Website:     www.ibiblio.org/apollo/index.html
014531,000018:                                                                                                  ## Mod history: 2016-12-13 MAS  Created from Luminary 99.
014532,000019:                                                                                                  ##              2017-01-14 RRB  Updated for Luminary 69.
014533,000020:                                                                                                  ##              2017-01-25 RSB  Proofed comment text using octopus/prooferComments
014534,000021:                                                                                                  ##                              and fixed errors found.
014535,000022: 

Page 334

014537,000024: 23,2041                                           BANK     23                                    
014538,000025: 13,2000                                           SETLOC   LEMGEOM                               
014539,000026: 13,2000                                           BANK                                           
014540,000027: 
014541,000028: 13,2070  30,2000                                  SBANK=   LOWSUPER                              
014542,000029: 13,2070  E5,1642                                  EBANK=   XSM                                   
014543,000030: 
014544,000031:                                                                                                  #  THESE TWO ROUTINES COMPUTE THE ACTUAL STATE VECTOR FOR LM,CSM BY ADDING
014545,000032:                                                                                                  #  THE CONIC R,V AND THE DEVIATIONSR,V. THE STATE VECTORS ARE CONVERTED TO
014546,000033:                                                                                                  #  METERS B-29 AND METERS/CSEC B-7 AND STORED APPROPRIATELY IN RN,VN OR
014547,000034:                                                                                                  #  R-OTHER , V-OTHER FOR DOWNLINK. THE ROUTINES NAMES ARE SWITCHED IN THE
014548,000035:                                                                                                  #  OTHER VEHICLES COMPUTER.
014549,000036: 
014550,000037:                                                                                                  #  INPUT
014551,000038:                                                                                                  #    STATE VECTOR IN TEMPORARY STORAGE AREA
014552,000039:                                                                                                  #    IF STATE VECTOR IS SCALED POS B27 AND VEL B5
014553,000040:                                                                                                  #       SET X2 TO +2
014554,000041:                                                                                                  #    IF STATE VECTOR IS SCALED POS B29 AND VEL B7
014555,000042:                                                                                                  #       SET X2 TO 0
014556,000043: 
014557,000044:                                                                                                  #  OUTPUT
014558,000045:                                                                                                  #    R(T) IN RN, V(T) IN VN, T IN PIPTIME
014559,000046:                                                                                                  #  OR
014560,000047:                                                                                                  #    R(T) IN R-OTHER, V(T) IN V-OTHER   (T IS DEFINED BY T-OTHER)
014561,000048: 
014562,000049: 13,2070                                           COUNT*   $$/GEOM                               
014563,000050: 13,2070           43414        SVDWN2             BOF      RVQ                                   #  SW=1=AVETOMID DOING W-MATRIX INTEG.
014564,000051: 13,2071           04756                                    AVEMIDSW                              
014565,000052: 13,2072           26073                                    +1                                    
014566,000053: 13,2073           53775                           VLOAD    VSL*                                  
014567,000054: 13,2074           01521                                    TDELTAV                               
014568,000055: 13,2075           57605                                    0          -7,2                       
014569,000056: 13,2076           53655                           VAD      VSL*                                  
014570,000057: 13,2077           01535                                    RCV                                   
014571,000058: 13,2100           57576                                    0,2                                   
014572,000059: 13,2101           25221                           STOVL    RN                                    
014573,000060: 13,2102           01527                                    TNUV                                  
014574,000061: 13,2103           53257                           VSL*     VAD                                   
014575,000062: 13,2104           57602                                    0          -4,2                       
014576,000063: 13,2105           01543                                    VCV                                   
014577,000064: 13,2106           77657                           VSL*                                           
014578,000065: 13,2107           57576                                    0,2                                   
014579,000066: 13,2110           15227                           STODL    VN                                    
014580,000067: 13,2111           01517                                    TET                                   
014581,000068: 13,2112           01235                           STORE    PIPTIME                               
014582,000069: 13,2113           77616                           RVQ                                            

Page 335

014584,000071: 13,2114           53775        SVDWN1             VLOAD    VSL*                                  
014585,000072: 13,2115           01521                                    TDELTAV                               
014586,000073: 13,2116           57605                                    0          -7,2                       
014587,000074: 13,2117           53655                           VAD      VSL*                                  
014588,000075: 13,2120           01535                                    RCV                                   
014589,000076: 13,2121           57576                                    0,2                                   
014590,000077: 13,2122           25720                           STOVL    R-OTHER                               
014591,000078: 13,2123           01527                                    TNUV                                  
014592,000079: 13,2124           53257                           VSL*     VAD                                   
014593,000080: 13,2125           57602                                    0          -4,2                       
014594,000081: 13,2126           01543                                    VCV                                   
014595,000082: 13,2127           77657                           VSL*                                           
014596,000083: 13,2130           57576                                    0,2                                   
014597,000084: 13,2131           01726                           STORE    V-OTHER                               
014598,000085: 13,2132           77616                           RVQ                                            
014599,000086: 

Page 336

014601,000088:                                                                                                  #           THE FOLLOWING ROUTINE TAKES A HALF UNIT TARGET VECTOR REFERRED TO NAV BASE COORDINATES AND FINDS BOTH
014602,000089:                                                                                                  #  GIMBAL ORIENTATIONS AT WHICH THE RR MIGHT SIGHT THE TARGET. THE GIMBAL ANGLES CORRESPONDING TO THE PRESENT MODE
014603,000090:                                                                                                  #  ARE LEFT IN MODEA AND THOSE WHICH WOULD BE USED AFTER A REMODE IN MODEB. THIS ROUTINE ASSUMES MODE 1 IS TRUNNION
014604,000091:                                                                                                  #  ANGLE LESS THAN 90 DEGS IN ABS VALUE WITH ARBITRARY SHAFT, WITH A CORRESPONDING DEFINITION FOR MODE 2. MODE
014605,000092:                                                                                                  #  SELECTION AND LIMIT CHECKING ARE DONE ELSEWHERE.
014606,000093: 
014607,000094:                                                                                                  #           THE MODE 1 CONFIGURATION IS CALCULATED FROM THE VECTOR AND THEN MODE 2 IS FOUND USING THE RELATIONS
014608,000095: 
014609,000096:                                                                                                  #           S(2) = 180 + S(1)
014610,000097:                                                                                                  #           T(2) = 180 - T(1)
014611,000098: 
014612,000099:                                                                                                  #      THE VECTOR ARRIVES IN MPAC WHERE TRG*SMNG OR *SMNB* WILL HAVE LEFT IT.
014613,000100: 
014614,000101: 13,2133           00041        RRANGLES           STORE    32D                                   
014615,000102: 13,2134           57545                           DLOAD    DCOMP                                 #  SINCE WE WILL FIND THE MODE 1 SHAFT
014616,000103: 13,2135           00043                                    34D                                   #  ANGLE LATER, WE CAN FIND THE MODE 1
014617,000104: 13,2136           67401                           SETPD    ASIN                                  #  TRUNNION BY SIMPLY TAKING THE ARCSIN OF
014618,000105: 13,2137           00001                                    0                                     #  THE Y COMPONENT, THE ASIN GIVING AN
014619,000106: 13,2140           44206                           PUSH     BDSU                                  #  ANSWER WHOSE ABS VAL IS LESS THAN 90 DEG
014620,000107: 13,2141           22273                                    LODPHALF                              
014621,000108: 13,2142           14005                           STODL    4                                     #  MODE 2 TRUNNION TO 4.
014622,000109: 
014623,000110: 13,2143           22275                                    LO6ZEROS                              
014624,000111: 13,2144           24043                           STOVL    34D                                   #  UNIT THE PROJECTION OF THE VECTOR
014625,000112: 13,2145           00041                                    32D                                   #    IN THE X-Z PLANE
014626,000113: 13,2146           41056                           UNIT     BOVB                                  #  IF OVERFLOW, TARGET VECTOR IS ALONG Y
014627,000114: 13,2147           52421                                    LUNDESCH                              #  CALL FOR MANEUVER UNLESS ON LUNAR SURF
014628,000115: 13,2150           14041                           STODL    32D                                   #  PROJECTION VECTOR.
014629,000116: 13,2151           00041                                    32D                                   
014630,000117: 13,2152           44142                           SR1      STQ                                   
014631,000118: 13,2153           00051                                    S2                                    
014632,000119: 13,2154           14023                           STODL    SINTH                                 #  USE ARCTRIG SINCE SHAFT COULD BE ARB.
014633,000120: 13,2155           00045                                    36D                                   
014634,000121: 13,2156           77742                           SR1                                            
014635,000122: 13,2157           34021                           STCALL   COSTH                                 
014636,000123: 13,2160           47222                                    ARCTRIG                               

Page 337

014638,000125: 13,2161           43206                           PUSH     DAD                                   #  MODE 1 SHAFT TO 2.
014639,000126: 13,2162           22273                                    LODPHALF                              
014640,000127: 13,2163           24007                           STOVL    6                                     
014641,000128: 13,2164           00005                                    4                                     
014642,000129: 13,2165           77634                           RTB                                            #  FIND MODE 2 CDU ANGLES.
014643,000130: 13,2166           21541                                    2V1STO2S                              
014644,000131: 13,2167           25112                           STOVL    MODEB                                 
014645,000132: 13,2170           00001                                    0                                     
014646,000133: 13,2171           77634                           RTB                                            #  MODE 1 ANGLES TO MODE A.
014647,000134: 13,2172           21541                                    2V1STO2S                              
014648,000135: 13,2173           01110                           STORE    MODEA                                 
014649,000136: 13,2174           77776                           EXIT                                           
014650,000137: 
014651,000138: 13,2175           40110                           CS       RADMODES                              #  SWAP MODEA AND MODEB IF RR IN MODE 2.
014652,000139: 13,2176           74740                           MASK     ANTENBIT                              
014653,000140: 13,2177           10000                           CCS      A                                     
014654,000141: 13,2200           12204                           TCF      +4                                    
014655,000142: 
014656,000143: 13,2201           53110                           DXCH     MODEA                                 
014657,000144: 13,2202           53112                           DXCH     MODEB                                 
014658,000145: 13,2203           53110                           DXCH     MODEA                                 
014659,000146: 
014660,000147: 13,2204           06036                           TC       INTPRET                               
014661,000148: 13,2205           77650                           GOTO                                           
014662,000149: 13,2206           00051                                    S2                                    

Page 338

014664,000151:                                                                                                  #  GIVEN RR TRUNNION AND SHAFT (T,S) IN TANGNB,+1, FIND THE ASSOCIATED
014665,000152:                                                                                                  #  LINE OF SIGHT IN NAV BASE AXES.  THE HALF UNIT VECTOR, .5(SIN(S)COS(T),
014666,000153:                                                                                                  #  -SIN(T),COS(S)COS(T)) IS LEFT IN MPAC AND 32D.
014667,000154: 
014668,000155: 23,2000                                           SETLOC   INFLIGHT                              
014669,000156: 23,2000                                           BANK                                           
014670,000157: 
014671,000158: 23,2041                                           COUNT*   $$/GEOM                               
014672,000159: 
014673,000160: 23,2041           47135        RRNB               SLOAD    RTB                                   
014674,000161: 23,2042           03751                                    TANGNB                                
014675,000162: 23,2043           21465                                    CDULOGIC                              
014676,000163: 23,2044           41401                           SETPD    PUSH                                  #  TRUNNION ANGLE TO 0
014677,000164: 23,2045           00001                                    0                                     
014678,000165: 23,2046           57556                           SIN      DCOMP                                 
014679,000166: 23,2047           14043                           STODL    34D                                   #  Y COMPONENT
014680,000167: 
014681,000168: 23,2050           41546                           COS      PUSH                                  #  .5 COS(T) TO 0
014682,000169: 23,2051           47135                           SLOAD    RTB                                   
014683,000170: 23,2052           03752                                    TANGNB     +1                         
014684,000171: 23,2053           21465                                    CDULOGIC                              
014685,000172: 23,2054           71406                           PUSH     COS                                   #  SHAFT ANGLE TO 2
014686,000173: 23,2055           72405                           DMP      SL1                                   
014687,000174: 23,2056           00001                                    0                                     
014688,000175: 23,2057           14045                           STODL    36D                                   #  Z COMPONENT
014689,000176: 
014690,000177: 23,2060           41356                           SIN      DMP                                   
014691,000178: 23,2061           77752                           SL1                                            
014692,000179: 23,2062           24041                           STOVL    32D                                   
014693,000180: 23,2063           00041                                    32D                                   
014694,000181: 23,2064           77616                           RVQ                                            

End of include-file LEM_GEOMETRY.agc.  Parent file is MAIN.agc