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!

013140,000002:                                                                                                  ## Copyright:   Public domain.
013141,000003:                                                                                                  ## Filename:    LEM_GEOMETRY.agc
013142,000004:                                                                                                  ## Purpose:     Part of the source code for Luminary 1A build 099.
013143,000005:                                                                                                  ##              It is part of the source code for the Lunar Module's (LM)
013144,000006:                                                                                                  ##              Apollo Guidance Computer (AGC), for Apollo 11.
013145,000007:                                                                                                  ## Assembler:   yaYUL
013146,000008:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
013147,000009:                                                                                                  ## Website:     www.ibiblio.org/apollo.
013148,000010:                                                                                                  ## Pages:       320-325
013149,000011:                                                                                                  ## Mod history: 2009-05-16 RSB  Adapted from the corresponding 
013150,000012:                                                                                                  ##                              Luminary131 file, using page 
013151,000013:                                                                                                  ##                              images from Luminary 1A.
013152,000014:                                                                                                  ##              2016-12-13 RSB  Proofed text comments with octopus/ProoferComments
013153,000015:                                                                                                  ##                              and corrected the errors found.
013154,000016:                                                                                                  ##              2017-03-03 RSB  Snapshot of Luminary 99 Rev 1. 
013155,000017:                                                                                                  ##              2017-03-07 RSB  Fixed comment-text error noticed while proofing
013156,000018:                                                                                                  ##                              Luminary 116.
013157,000019: 

Page 320

013159,000021: 23,2041                                           BANK     23                                    
013160,000022: 13,2000                                           SETLOC   LEMGEOM                               
013161,000023: 13,2000                                           BANK                                           
013162,000024: 
013163,000025: 13,2070  30,2000                                  SBANK=   LOWSUPER                              
013164,000026: 13,2070  E5,1642                                  EBANK=   XSM                                   
013165,000027: 
013166,000028:                                                                                                  #  THESE TWO ROUTINES COMPUTE THE ACTUAL STATE VECTOR FOR LM,CSM BY ADDING
013167,000029:                                                                                                  #  THE CONIC R,V AND THE DEVIATIONS R,V.  THE STATE VECTORS ARE CONVERTED TO
013168,000030:                                                                                                  #  METERS B-29 AND METERS/CSEC B-7 AND STORED APPROPRIATELY IN RN,VN OR
013169,000031:                                                                                                  #  R-OTHER,V-OTHER FOR DOWNLINK.  THE ROUTINES NAMES ARE SWITCHED IN THE
013170,000032:                                                                                                  #  OTHER VEHICLES COMPUTER.
013171,000033: 
013172,000034:                                                                                                  #  INPUT
013173,000035:                                                                                                  #        STATE VECTOR IN TEMPORARY STORAGE AREA
013174,000036:                                                                                                  #        IF STATE VECTOR IS SCALED POS B27 AND VEL B5
013175,000037:                                                                                                  #                SET X2 TO +2
013176,000038:                                                                                                  #        IF STATE VECTOR IS SCALED POS B29 AND VEL B7
013177,000039:                                                                                                  #                SET X2 TO 0
013178,000040: 
013179,000041:                                                                                                  #  OUTPUT
013180,000042:                                                                                                  #        R(T) IN RN, V(T) IN VN, T IN PIPTIME
013181,000043:                                                                                                  #  OR
013182,000044:                                                                                                  #        R(T) IN R-OTHER, V(T) IN V-OTHER        (T IS DEFINED BY T-OTHER)
013183,000045: 
013184,000046: 13,2070                                           COUNT*   $$/GEOM                               
013185,000047: 13,2070           43414        SVDWN2             BOF      RVQ                                   #  SW=1=AVETOMID DOING W-MATRIX INTEG.
013186,000048: 13,2071           04756                                    AVEMIDSW                              
013187,000049: 13,2072           26073                                    +1                                    
013188,000050: 13,2073           53775                           VLOAD    VSL*                                  
013189,000051: 13,2074           01521                                    TDELTAV                               
013190,000052: 13,2075           57605                                    0          -7,2                       
013191,000053: 13,2076           53655                           VAD      VSL*                                  
013192,000054: 13,2077           01535                                    RCV                                   
013193,000055: 13,2100           57576                                    0,2                                   
013194,000056: 13,2101           25221                           STOVL    RN                                    
013195,000057: 13,2102           01527                                    TNUV                                  
013196,000058: 13,2103           53257                           VSL*     VAD                                   
013197,000059: 13,2104           57602                                    0          -4,2                       
013198,000060: 13,2105           01543                                    VCV                                   
013199,000061: 13,2106           77657                           VSL*                                           
013200,000062: 13,2107           57576                                    0,2                                   
013201,000063: 13,2110           15227                           STODL    VN                                    
013202,000064: 13,2111           01517                                    TET                                   
013203,000065: 13,2112           01235                           STORE    PIPTIME                               
013204,000066: 13,2113           77616                           RVQ                                            

Page 321

013206,000068: 13,2114           53775        SVDWN1             VLOAD    VSL*                                  
013207,000069: 13,2115           01521                                    TDELTAV                               
013208,000070: 13,2116           57605                                    0          -7,2                       
013209,000071: 13,2117           53655                           VAD      VSL*                                  
013210,000072: 13,2120           01535                                    RCV                                   
013211,000073: 13,2121           57576                                    0,2                                   
013212,000074: 13,2122           25720                           STOVL    R-OTHER                               
013213,000075: 13,2123           01527                                    TNUV                                  
013214,000076: 13,2124           53257                           VSL*     VAD                                   
013215,000077: 13,2125           57602                                    0          -4,2                       
013216,000078: 13,2126           01543                                    VCV                                   
013217,000079: 13,2127           77657                           VSL*                                           
013218,000080: 13,2130           57576                                    0,2                                   
013219,000081: 13,2131           01726                           STORE    V-OTHER                               
013220,000082: 13,2132           77616                           RVQ                                            
013221,000083: 

Page 322

013223,000085:                                                                                                  #  THE FOLLOWING ROUTINE TAKES A HALF UNIT TARGET VECTOR REFERRED TO NAV BASE COORDINATES AND FINDS BOTH
013224,000086:                                                                                                  #  GIMBAL ORIENTATIONS AT WHICH THE RR MIGHT SIGHT THE TARGET.  THE GIMBAL ANGLES CORRESPONDING TO THE PRESENT MODE
013225,000087:                                                                                                  #  ARE LEFT IN MODEA AND THOSE WHICH WOULD BE USED AFTER A REMODE IN MODEB.  THIS ROUTINE ASSUMES MODE 1 IS TRUNNION
013226,000088:                                                                                                  #  ANGLE LESS THAN 90 DEGS IN ABS VALUE WITH ARBITRARY SHAFT, WITH A CORRESPONDING DEFINITION FOR MODE 2.  MODE
013227,000089:                                                                                                  #  SELECTION AND LIMIT CHECKING ARE DONE ELSEWHERE.
013228,000090: 
013229,000091:                                                                                                  #  THE MODE 1 CONFIGURATION IS CALCULATED FROM THE VECTOR AND THEN MODE 2 IS FOUND USING THE RELATIONS
013230,000092: 
013231,000093:                                                                                                  #        S(2) = 180 + S(1)
013232,000094:                                                                                                  #        T(2) = 180 - T(1)
013233,000095: 
013234,000096:                                                                                                  #  THE VECTOR ARRIVES IN MPAC WHERE TRG*SMNG OR *SMNB* WILL HAVE LEFT IT.
013235,000097: 
013236,000098: 13,2133           00041        RRANGLES           STORE    32D                                   
013237,000099: 13,2134           57545                           DLOAD    DCOMP                                 #  SINCE WE WILL FIND THE MODE 1 SHAFT
013238,000100: 13,2135           00043                                    34D                                   #  ANGLE LATER, WE CAN FIND THE MODE 1
013239,000101: 13,2136           67401                           SETPD    ASIN                                  #  TRUNNION BY SIMPLY TAKING THE ARCSIN OF
013240,000102: 13,2137           00001                                    0                                     #  THE Y COMPONENT, THE ASIN GIVING AN
013241,000103: 13,2140           44206                           PUSH     BDSU                                  #  ANSWER WHOSE ABS VAL IS LESS THAN 90 DEG
013242,000104: 13,2141           24005                                    LODPHALF                              
013243,000105: 13,2142           14005                           STODL    4                                     #  MODE 2 TRUNNION TO 4.
013244,000106: 
013245,000107: 13,2143           24007                                    LO6ZEROS                              
013246,000108: 13,2144           24043                           STOVL    34D                                   #  UNIT THE PROJECTION OF THE VECTOR
013247,000109: 13,2145           00041                                    32D                                   #        IN THE X-Z PLANE
013248,000110: 13,2146           41056                           UNIT     BOVB                                  #  IF OVERFLOW, TARGET VECTOR IS ALONG Y
013249,000111: 13,2147           52421                                    LUNDESCH                              #  CALL FOR MANEUVER UNLESS ON LUNAR SURF
013250,000112: 13,2150           14041                           STODL    32D                                   #  PROJECTION VECTOR.
013251,000113: 13,2151           00041                                    32D                                   
013252,000114: 13,2152           44142                           SR1      STQ                                   
013253,000115: 13,2153           00051                                    S2                                    
013254,000116: 13,2154           14023                           STODL    SINTH                                 #  USE ARCTRIG SINCE SHAFT COULD BE ARB.
013255,000117: 13,2155           00045                                    36D                                   
013256,000118: 13,2156           77742                           SR1                                            
013257,000119: 13,2157           34021                           STCALL   COSTH                                 
013258,000120: 13,2160           47320                                    ARCTRIG                               

Page 323

013260,000122: 13,2161           43206                           PUSH     DAD                                   #  MODE 1 SHAFT TO 2.
013261,000123: 13,2162           24005                                    LODPHALF                              
013262,000124: 13,2163           24007                           STOVL    6                                     
013263,000125: 13,2164           00005                                    4                                     
013264,000126: 13,2165           77634                           RTB                                            #  FIND MODE 2 CDU ANGLES.
013265,000127: 13,2166           21635                                    2V1STO2S                              
013266,000128: 13,2167           25112                           STOVL    MODEB                                 
013267,000129: 13,2170           00001                                    0                                     
013268,000130: 13,2171           77634                           RTB                                            #  MODE 1 ANGLES TO MODE A.
013269,000131: 13,2172           21635                                    2V1STO2S                              
013270,000132: 13,2173           01110                           STORE    MODEA                                 
013271,000133: 13,2174           77776                           EXIT                                           
013272,000134: 
013273,000135: 13,2175           40110                           CS       RADMODES                              #  SWAP MODEA AND MODEB IF RR IN MODE 2.
013274,000136: 13,2176           74740                           MASK     ANTENBIT                              
013275,000137: 13,2177           10000                           CCS      A                                     
013276,000138: 13,2200           12204                           TCF      +4                                    
013277,000139: 
013278,000140: 13,2201           53110                           DXCH     MODEA                                 
013279,000141: 13,2202           53112                           DXCH     MODEB                                 
013280,000142: 13,2203           53110                           DXCH     MODEA                                 
013281,000143: 
013282,000144: 13,2204           06037                           TC       INTPRET                               
013283,000145: 13,2205           77650                           GOTO                                           
013284,000146: 13,2206           00051                                    S2                                    

Page 324

013286,000148:                                                                                                  #  GIVEN RR TRUNNION AND SHAFT (T,S) IN TANGNB,+1, FIND THE ASSOCIATED
013287,000149:                                                                                                  #  LINE OF SIGHT IN NAV BASE AXES.  THE HALF UNIT VECTOR, .5(SIN(S)COS(T),
013288,000150:                                                                                                  #  -SIN(T),COS(S)COS(T)) IS LEFT IN MPAC AND 32D.
013289,000151: 
013290,000152: 23,2000                                           SETLOC   INFLIGHT                              
013291,000153: 23,2000                                           BANK                                           
013292,000154: 
013293,000155: 23,2041                                           COUNT*   $$/GEOM                               
013294,000156: 
013295,000157: 23,2041           47135        RRNB               SLOAD    RTB                                   
013296,000158: 23,2042           03753                                    TANGNB                                
013297,000159: 23,2043           21576                                    CDULOGIC                              
013298,000160: 23,2044           41401                           SETPD    PUSH                                  #  TRUNNION ANGLE TO 0
013299,000161: 23,2045           00001                                    0                                     
013300,000162: 23,2046           57556                           SIN      DCOMP                                 
013301,000163: 23,2047           14043                           STODL    34D                                   #  Y COMPONENT
013302,000164: 
013303,000165: 23,2050           41546                           COS      PUSH                                  #  .5 COS(T) TO 0
013304,000166: 23,2051           47135                           SLOAD    RTB                                   
013305,000167: 23,2052           03754                                    TANGNB     +1                         
013306,000168: 23,2053           21576                                    CDULOGIC                              
013307,000169: 23,2054           71406        RRNB1              PUSH     COS                                   #  SHAFT ANGLE TO 2
013308,000170: 23,2055           72405                           DMP      SL1                                   
013309,000171: 23,2056           00001                                    0                                     
013310,000172: 23,2057           14045                           STODL    36D                                   #  Z COMPONENT
013311,000173: 
013312,000174: 23,2060           41356                           SIN      DMP                                   
013313,000175: 23,2061           77752                           SL1                                            
013314,000176: 23,2062           24041                           STOVL    32D                                   
013315,000177: 23,2063           00041                                    32D                                   
013316,000178: 23,2064           77616                           RVQ                                            
013317,000179: 
013318,000180:                                                                                                  #  THIS ENTRY TO RRNB REQUIRES THE TRUNNION AND SHAFT ANGLES IN MPAC AND MPAC +1 RESPECTIVELY
013319,000181: 
013320,000182: 23,2065           14025        RRNBMPAC           STODL    20D                                   #  SAVE SHAFT CDU IN 21.
013321,000183: 23,2066           00155                                    MPAC                                  #  SET MODE TO DP.  (THE PRECEEDING STORE
013322,000184:                                                                                                  #  MAY BE DP, TP OR VECTOR.)
013323,000185: 23,2067           40234                           RTB      SETPD                                 
013324,000186: 23,2070           21576                                    CDULOGIC                              
013325,000187: 23,2071           00001                                    0                                     
013326,000188: 23,2072           73406                           PUSH     SIN                                   #  TRUNNION ANGLE TO 0
013327,000189: 23,2073           77676                           DCOMP                                          
013328,000190: 23,2074           14043                           STODL    34D                                   #  Y COMPONENT
013329,000191: 23,2075           41546                           COS      PUSH                                  #  .5COS(T) TO 0
013330,000192: 23,2076           47135                           SLOAD    RTB                                   #  PICK UP CDU'S.
013331,000193: 23,2077           00026                                    21D                                   
013332,000194: 23,2100           21576                                    CDULOGIC                              
013333,000195: 23,2101           77650                           GOTO                                           
013334,000196: 23,2102           46054                                    RRNB1                                 

Page 325

013336,000198:                                                                                                  #  (This page has nothing on it.)
013337,000199: 
013338,000200: 

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