Source Code

This is an attempt to recreate Luminary 99 Rev 2, otherwise known as LUM99R2, from Luminary 99 Rev 1 and ephemeris data from Luminary 116. The differences are confined to the last 10-12 lines of the CONTROLLED CONSTANTS. Luminary 99 Rev 1 source-code was transcribed from a printout in the MIT Museum, while Luminary 116 source code was transcribed from a printout belonging to Don Eyles. AGC developer James Kernan, the "rope mother" for the Apollo 11 Lunar Module's AGC, explains as follows: "At the last minute, Dan Lickly, our chief engineer, appeared with ephemerides updates and it took two tries to get it right. The result was that we created Lum99 Revision 1 and Lum99 Revision 2." It is suspected that the former is what's in the MIT Museum, and the latter is what we are trying to recreate here. As for which revision actually flew in Apollo 11, all of the other available surviving evidence points to Rev 1 rather than to Rev 2, so we're just not sure!

013141,000002:                                                                                                  ## Copyright:   Public domain.
013142,000003:                                                                                                  ## Filename:    LEM_GEOMETRY.agc
013143,000004:                                                                                                  ## Purpose:     Part of the source code for Luminary 1A build 099.
013144,000005:                                                                                                  ##              It is part of the source code for the Lunar Module's (LM)
013145,000006:                                                                                                  ##              Apollo Guidance Computer (AGC), for Apollo 11.
013146,000007:                                                                                                  ## Assembler:   yaYUL
013147,000008:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
013148,000009:                                                                                                  ## Website:     www.ibiblio.org/apollo.
013149,000010:                                                                                                  ## Pages:       320-325
013150,000011:                                                                                                  ## Mod history: 2009-05-16 RSB  Adapted from the corresponding 
013151,000012:                                                                                                  ##                              Luminary131 file, using page 
013152,000013:                                                                                                  ##                              images from Luminary 1A.
013153,000014:                                                                                                  ##              2016-12-13 RSB  Proofed text comments with octopus/ProoferComments
013154,000015:                                                                                                  ##                              and corrected the errors found.
013155,000016:                                                                                                  ##              2017-03-03 RSB  Snapshot of Luminary 99 Rev 1. 
013156,000017:                                                                                                  ##              2017-03-07 RSB  Fixed comment-text error noticed while proofing
013157,000018:                                                                                                  ##                              Luminary 116.
013158,000019: 

Page 320

013160,000021: 23,2041                                           BANK     23                                    
013161,000022: 13,2000                                           SETLOC   LEMGEOM                               
013162,000023: 13,2000                                           BANK                                           
013163,000024: 
013164,000025: 13,2070  30,2000                                  SBANK=   LOWSUPER                              
013165,000026: 13,2070  E5,1642                                  EBANK=   XSM                                   
013166,000027: 
013167,000028:                                                                                                  #  THESE TWO ROUTINES COMPUTE THE ACTUAL STATE VECTOR FOR LM,CSM BY ADDING
013168,000029:                                                                                                  #  THE CONIC R,V AND THE DEVIATIONS R,V.  THE STATE VECTORS ARE CONVERTED TO
013169,000030:                                                                                                  #  METERS B-29 AND METERS/CSEC B-7 AND STORED APPROPRIATELY IN RN,VN OR
013170,000031:                                                                                                  #  R-OTHER,V-OTHER FOR DOWNLINK.  THE ROUTINES NAMES ARE SWITCHED IN THE
013171,000032:                                                                                                  #  OTHER VEHICLES COMPUTER.
013172,000033: 
013173,000034:                                                                                                  #  INPUT
013174,000035:                                                                                                  #        STATE VECTOR IN TEMPORARY STORAGE AREA
013175,000036:                                                                                                  #        IF STATE VECTOR IS SCALED POS B27 AND VEL B5
013176,000037:                                                                                                  #                SET X2 TO +2
013177,000038:                                                                                                  #        IF STATE VECTOR IS SCALED POS B29 AND VEL B7
013178,000039:                                                                                                  #                SET X2 TO 0
013179,000040: 
013180,000041:                                                                                                  #  OUTPUT
013181,000042:                                                                                                  #        R(T) IN RN, V(T) IN VN, T IN PIPTIME
013182,000043:                                                                                                  #  OR
013183,000044:                                                                                                  #        R(T) IN R-OTHER, V(T) IN V-OTHER        (T IS DEFINED BY T-OTHER)
013184,000045: 
013185,000046: 13,2070                                           COUNT*   $$/GEOM                               
013186,000047: 13,2070           43414        SVDWN2             BOF      RVQ                                   #  SW=1=AVETOMID DOING W-MATRIX INTEG.
013187,000048: 13,2071           04756                                    AVEMIDSW                              
013188,000049: 13,2072           26073                                    +1                                    
013189,000050: 13,2073           53775                           VLOAD    VSL*                                  
013190,000051: 13,2074           01521                                    TDELTAV                               
013191,000052: 13,2075           57605                                    0          -7,2                       
013192,000053: 13,2076           53655                           VAD      VSL*                                  
013193,000054: 13,2077           01535                                    RCV                                   
013194,000055: 13,2100           57576                                    0,2                                   
013195,000056: 13,2101           25221                           STOVL    RN                                    
013196,000057: 13,2102           01527                                    TNUV                                  
013197,000058: 13,2103           53257                           VSL*     VAD                                   
013198,000059: 13,2104           57602                                    0          -4,2                       
013199,000060: 13,2105           01543                                    VCV                                   
013200,000061: 13,2106           77657                           VSL*                                           
013201,000062: 13,2107           57576                                    0,2                                   
013202,000063: 13,2110           15227                           STODL    VN                                    
013203,000064: 13,2111           01517                                    TET                                   
013204,000065: 13,2112           01235                           STORE    PIPTIME                               
013205,000066: 13,2113           77616                           RVQ                                            

Page 321

013207,000068: 13,2114           53775        SVDWN1             VLOAD    VSL*                                  
013208,000069: 13,2115           01521                                    TDELTAV                               
013209,000070: 13,2116           57605                                    0          -7,2                       
013210,000071: 13,2117           53655                           VAD      VSL*                                  
013211,000072: 13,2120           01535                                    RCV                                   
013212,000073: 13,2121           57576                                    0,2                                   
013213,000074: 13,2122           25720                           STOVL    R-OTHER                               
013214,000075: 13,2123           01527                                    TNUV                                  
013215,000076: 13,2124           53257                           VSL*     VAD                                   
013216,000077: 13,2125           57602                                    0          -4,2                       
013217,000078: 13,2126           01543                                    VCV                                   
013218,000079: 13,2127           77657                           VSL*                                           
013219,000080: 13,2130           57576                                    0,2                                   
013220,000081: 13,2131           01726                           STORE    V-OTHER                               
013221,000082: 13,2132           77616                           RVQ                                            
013222,000083: 

Page 322

013224,000085:                                                                                                  #  THE FOLLOWING ROUTINE TAKES A HALF UNIT TARGET VECTOR REFERRED TO NAV BASE COORDINATES AND FINDS BOTH
013225,000086:                                                                                                  #  GIMBAL ORIENTATIONS AT WHICH THE RR MIGHT SIGHT THE TARGET.  THE GIMBAL ANGLES CORRESPONDING TO THE PRESENT MODE
013226,000087:                                                                                                  #  ARE LEFT IN MODEA AND THOSE WHICH WOULD BE USED AFTER A REMODE IN MODEB.  THIS ROUTINE ASSUMES MODE 1 IS TRUNNION
013227,000088:                                                                                                  #  ANGLE LESS THAN 90 DEGS IN ABS VALUE WITH ARBITRARY SHAFT, WITH A CORRESPONDING DEFINITION FOR MODE 2.  MODE
013228,000089:                                                                                                  #  SELECTION AND LIMIT CHECKING ARE DONE ELSEWHERE.
013229,000090: 
013230,000091:                                                                                                  #  THE MODE 1 CONFIGURATION IS CALCULATED FROM THE VECTOR AND THEN MODE 2 IS FOUND USING THE RELATIONS
013231,000092: 
013232,000093:                                                                                                  #        S(2) = 180 + S(1)
013233,000094:                                                                                                  #        T(2) = 180 - T(1)
013234,000095: 
013235,000096:                                                                                                  #  THE VECTOR ARRIVES IN MPAC WHERE TRG*SMNG OR *SMNB* WILL HAVE LEFT IT.
013236,000097: 
013237,000098: 13,2133           00041        RRANGLES           STORE    32D                                   
013238,000099: 13,2134           57545                           DLOAD    DCOMP                                 #  SINCE WE WILL FIND THE MODE 1 SHAFT
013239,000100: 13,2135           00043                                    34D                                   #  ANGLE LATER, WE CAN FIND THE MODE 1
013240,000101: 13,2136           67401                           SETPD    ASIN                                  #  TRUNNION BY SIMPLY TAKING THE ARCSIN OF
013241,000102: 13,2137           00001                                    0                                     #  THE Y COMPONENT, THE ASIN GIVING AN
013242,000103: 13,2140           44206                           PUSH     BDSU                                  #  ANSWER WHOSE ABS VAL IS LESS THAN 90 DEG
013243,000104: 13,2141           24005                                    LODPHALF                              
013244,000105: 13,2142           14005                           STODL    4                                     #  MODE 2 TRUNNION TO 4.
013245,000106: 
013246,000107: 13,2143           24007                                    LO6ZEROS                              
013247,000108: 13,2144           24043                           STOVL    34D                                   #  UNIT THE PROJECTION OF THE VECTOR
013248,000109: 13,2145           00041                                    32D                                   #        IN THE X-Z PLANE
013249,000110: 13,2146           41056                           UNIT     BOVB                                  #  IF OVERFLOW, TARGET VECTOR IS ALONG Y
013250,000111: 13,2147           52421                                    LUNDESCH                              #  CALL FOR MANEUVER UNLESS ON LUNAR SURF
013251,000112: 13,2150           14041                           STODL    32D                                   #  PROJECTION VECTOR.
013252,000113: 13,2151           00041                                    32D                                   
013253,000114: 13,2152           44142                           SR1      STQ                                   
013254,000115: 13,2153           00051                                    S2                                    
013255,000116: 13,2154           14023                           STODL    SINTH                                 #  USE ARCTRIG SINCE SHAFT COULD BE ARB.
013256,000117: 13,2155           00045                                    36D                                   
013257,000118: 13,2156           77742                           SR1                                            
013258,000119: 13,2157           34021                           STCALL   COSTH                                 
013259,000120: 13,2160           47320                                    ARCTRIG                               

Page 323

013261,000122: 13,2161           43206                           PUSH     DAD                                   #  MODE 1 SHAFT TO 2.
013262,000123: 13,2162           24005                                    LODPHALF                              
013263,000124: 13,2163           24007                           STOVL    6                                     
013264,000125: 13,2164           00005                                    4                                     
013265,000126: 13,2165           77634                           RTB                                            #  FIND MODE 2 CDU ANGLES.
013266,000127: 13,2166           21635                                    2V1STO2S                              
013267,000128: 13,2167           25112                           STOVL    MODEB                                 
013268,000129: 13,2170           00001                                    0                                     
013269,000130: 13,2171           77634                           RTB                                            #  MODE 1 ANGLES TO MODE A.
013270,000131: 13,2172           21635                                    2V1STO2S                              
013271,000132: 13,2173           01110                           STORE    MODEA                                 
013272,000133: 13,2174           77776                           EXIT                                           
013273,000134: 
013274,000135: 13,2175           40110                           CS       RADMODES                              #  SWAP MODEA AND MODEB IF RR IN MODE 2.
013275,000136: 13,2176           74740                           MASK     ANTENBIT                              
013276,000137: 13,2177           10000                           CCS      A                                     
013277,000138: 13,2200           12204                           TCF      +4                                    
013278,000139: 
013279,000140: 13,2201           53110                           DXCH     MODEA                                 
013280,000141: 13,2202           53112                           DXCH     MODEB                                 
013281,000142: 13,2203           53110                           DXCH     MODEA                                 
013282,000143: 
013283,000144: 13,2204           06037                           TC       INTPRET                               
013284,000145: 13,2205           77650                           GOTO                                           
013285,000146: 13,2206           00051                                    S2                                    

Page 324

013287,000148:                                                                                                  #  GIVEN RR TRUNNION AND SHAFT (T,S) IN TANGNB,+1, FIND THE ASSOCIATED
013288,000149:                                                                                                  #  LINE OF SIGHT IN NAV BASE AXES.  THE HALF UNIT VECTOR, .5(SIN(S)COS(T),
013289,000150:                                                                                                  #  -SIN(T),COS(S)COS(T)) IS LEFT IN MPAC AND 32D.
013290,000151: 
013291,000152: 23,2000                                           SETLOC   INFLIGHT                              
013292,000153: 23,2000                                           BANK                                           
013293,000154: 
013294,000155: 23,2041                                           COUNT*   $$/GEOM                               
013295,000156: 
013296,000157: 23,2041           47135        RRNB               SLOAD    RTB                                   
013297,000158: 23,2042           03753                                    TANGNB                                
013298,000159: 23,2043           21576                                    CDULOGIC                              
013299,000160: 23,2044           41401                           SETPD    PUSH                                  #  TRUNNION ANGLE TO 0
013300,000161: 23,2045           00001                                    0                                     
013301,000162: 23,2046           57556                           SIN      DCOMP                                 
013302,000163: 23,2047           14043                           STODL    34D                                   #  Y COMPONENT
013303,000164: 
013304,000165: 23,2050           41546                           COS      PUSH                                  #  .5 COS(T) TO 0
013305,000166: 23,2051           47135                           SLOAD    RTB                                   
013306,000167: 23,2052           03754                                    TANGNB     +1                         
013307,000168: 23,2053           21576                                    CDULOGIC                              
013308,000169: 23,2054           71406        RRNB1              PUSH     COS                                   #  SHAFT ANGLE TO 2
013309,000170: 23,2055           72405                           DMP      SL1                                   
013310,000171: 23,2056           00001                                    0                                     
013311,000172: 23,2057           14045                           STODL    36D                                   #  Z COMPONENT
013312,000173: 
013313,000174: 23,2060           41356                           SIN      DMP                                   
013314,000175: 23,2061           77752                           SL1                                            
013315,000176: 23,2062           24041                           STOVL    32D                                   
013316,000177: 23,2063           00041                                    32D                                   
013317,000178: 23,2064           77616                           RVQ                                            
013318,000179: 
013319,000180:                                                                                                  #  THIS ENTRY TO RRNB REQUIRES THE TRUNNION AND SHAFT ANGLES IN MPAC AND MPAC +1 RESPECTIVELY
013320,000181: 
013321,000182: 23,2065           14025        RRNBMPAC           STODL    20D                                   #  SAVE SHAFT CDU IN 21.
013322,000183: 23,2066           00155                                    MPAC                                  #  SET MODE TO DP.  (THE PRECEEDING STORE
013323,000184:                                                                                                  #  MAY BE DP, TP OR VECTOR.)
013324,000185: 23,2067           40234                           RTB      SETPD                                 
013325,000186: 23,2070           21576                                    CDULOGIC                              
013326,000187: 23,2071           00001                                    0                                     
013327,000188: 23,2072           73406                           PUSH     SIN                                   #  TRUNNION ANGLE TO 0
013328,000189: 23,2073           77676                           DCOMP                                          
013329,000190: 23,2074           14043                           STODL    34D                                   #  Y COMPONENT
013330,000191: 23,2075           41546                           COS      PUSH                                  #  .5COS(T) TO 0
013331,000192: 23,2076           47135                           SLOAD    RTB                                   #  PICK UP CDU'S.
013332,000193: 23,2077           00026                                    21D                                   
013333,000194: 23,2100           21576                                    CDULOGIC                              
013334,000195: 23,2101           77650                           GOTO                                           
013335,000196: 23,2102           46054                                    RRNB1                                 

Page 325

013337,000198:                                                                                                  #  (This page has nothing on it.)
013338,000199: 
013339,000200: 

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