Source Code

These source-code files were obtained by digitally photographing the Colossus 237 program listing from the private collection of original AGC developer Fred Martin, and then modifying pre-existing Colossus 249 (Apollo 9) source files to incorporate changes. Note that the page images presented online are of reduced quality, and that additional images are available. Report any conversion errors or legibility problems in page images to info@sandroid.org. Notations on the program listing read, in part:

	GAP: ASSEMBLE REVISION 237 OF AGC PROGRAM COLOSSUS 
	BY NASA 2021111-031  1:17 AUG. 24, 1968

032220,000002:                                                                                                 #  Copyright:    Public domain.
032221,000003:                                                                                                 #  Filename:      LUNAR_AND_SOLAR_EPHEMERIDES_SUBROUTINES.agc
032222,000004:                                                                                                 #  Purpose:      Part of the source code for Colossus build 237.
032223,000005:                                                                                                 #                This is for the Command Module's (CM) Apollo Guidance
032224,000006:                                                                                                 #                Computer (AGC), we believe for Apollo 8.
032225,000007:                                                                                                 #  Assembler:    yaYUL
032226,000008:                                                                                                 #  Contact:      Jim Lawton <jim DOT lawton AT gmail DOT com>
032227,000009:                                                                                                 #  Website:      www.ibiblio.org/apollo/index.html
032228,000010:                                                                                                 #  Page scans:   www.ibiblio.org/apollo/ScansForConversion/Colossus237/
032229,000011:                                                                                                 #  Mod history:  2011-02-27 JL    Adapted from corresponding Colossus 249 file.
032230,000012: 
032231,000013:                                                                                                 # # Page 736
032232,000014:                                                                                                 #  LUNAR AND SOLAR EPHEMERIDES SUBROUTINES
032233,000015: 
032234,000016:                                                                                                 #  FUNCTIONAL DESCRIPTION
032235,000017: 
032236,000018:                                                                                                 #        THESE SUBROUTINES ARE USED TO DETERMINE THE POSITION AND VELOCITY
032237,000019:                                                                                                 #        VECTORS OF THE SUN AND THE MOON RELATIVE TO THE EARTH AT THE
032238,000020:                                                                                                 #        SPECIFIED GROUND ELAPSED TIME INPUT BY THE USER.
032239,000021: 
032240,000022:                                                                                                 #        THE POSITION OF THE MOON IS STORED IN THE COMPUTER IN THE FORM OF
032241,000023:                                                                                                 #        A NINTH DEGREE POLYNOMIAL APPROXIMATION WHICH IS VALID OVER A 15
032242,000024:                                                                                                 #        DAY INTERVAL BEGINNING SHORTLY BEFORE LAUNCH.  THEREFORE THE TIME
032243,000025:                                                                                                 #        INPUT BY THE USER SHOULD FALL WITHIN THIS 15 DAY INTERVAL.
032244,000026: 
032245,000027:                                                                                                 #        LSPOS COMPUTES THE POSITION VECTORS OF THE SUN AND THE MOON.
032246,000028: 
032247,000029:                                                                                                 #        LUNPOS COMPUTES THE POSITION VECTOR OF THE MOON.
032248,000030: 
032249,000031:                                                                                                 #        LUNVEL COMPUTES THE VELOCITY VECTOR OF THE MOON.
032250,000032: 
032251,000033:                                                                                                 #        SOLPOS COMPUTES THE POSITION VECTOR OF THE SUN.
032252,000034: 
032253,000035:                                                                                                 #  CALLING SEQUENCE
032254,000036: 
032255,000037:                                                                                                 #        DLOAD  CALL
032256,000038:                                                                                                 #               TIME               GROUND ELAPSED TIME
032257,000039:                                                                                                 #               SUBROUTINE         LSPOS OR LUNPOS OR LUNVEL OR SOLPOS
032258,000040: 
032259,000041:                                                                                                 #  INPUT
032260,000042: 
032261,000043:                                                                                                 #        1) SPECIFIED GROUND ELAPSED TIME IN CS X B-28 LOADED IN MPAC.
032262,000044: 
032263,000045:                                                                                                 #        2) TIMEMO - TIME AT THE CENTER OF THE RANGE OVER WHICH THE LUNAR
032264,000046:                                                                                                 #           POSITION POLYNOMIAL IS VALID IN CS X B-42.
032265,000047: 
032266,000048:                                                                                                 #        3) VECOEM - VECTOR COEFFICIENTS OF THE LUNAR POSITION POLYNOMIAL
032267,000049:                                                                                                 #           LOADED IN DESCENDING SEQUENCE IN METERS/CS**N X B-2
032268,000050: 
032269,000051:                                                                                                 #        4) RESO - POSITION VECTOR OF THE SUN RELATIVE TO THE EARTH AT
032270,000052:                                                                                                 #           TIMEMO IN METERS X B-38.
032271,000053: 
032272,000054:                                                                                                 #        5) VESO - VELOCITY VECTOR OF THE SUN RELATIVE TO THE EARTH AT
032273,000055:                                                                                                 #           TIMEMO IN METERS/CS X B-9.
032274,000056: 
032275,000057:                                                                                                 #        6) OMEGAES - ANGULAR VELOCITY OF THE VECTOR RESO AT TIMEMO IN
032276,000058:                                                                                                 #           REV/CS X B+26.
032277,000059: 
032278,000060:                                                                                                 #        ALL EXCEPT THE FIRST INPUT ARE INCLUDED IN THE PRE-LAUNCH
032279,000061:                                                                                                 #        ERASABLE DATA LOAD.
032280,000062: 
032281,000063:                                                                                                 #  OUTPUT - LSPOS
032282,000064:                                                                                                 # # Page 737
032283,000065:                                                                                                 #        1) 2D OF VAC AREA CONTAINS THE POSITION VECTOR OF THE SUN RELATIVE
032284,000066:                                                                                                 #           TO THE EARTH AT TIME INPUT BY THE USER IN METERS X B-38.
032285,000067: 
032286,000068:                                                                                                 #        2) MPAC CONTAINS THE POSITION VECTOR OF THE MOON RELATIVE TO THE
032287,000069:                                                                                                 #           EARTH AT TIME INPUT BY THE USER IN METERS X B-29.
032288,000070: 
032289,000071:                                                                                                 #  OUTPUT - LUNPOS
032290,000072: 
032291,000073:                                                                                                 #        MPAC CONTAINS THE POSITION VECTOR OF THE MOON RELATIVE TO THE
032292,000074:                                                                                                 #        EARTH AT THE TIME INPUT BY USER IN METERS X B-29.
032293,000075: 
032294,000076:                                                                                                 #  OUTPUT - LUNVEL
032295,000077: 
032296,000078:                                                                                                 #        MPAC CONTAINS THE VELOCITY VECTOR OF THE MOON RELATIVE TO THE
032297,000079:                                                                                                 #        EARTH AT THE TIME INPUT BY THE USER IN METERS/CS X B-7.
032298,000080: 
032299,000081:                                                                                                 #  OUTPUT - SOLPOS
032300,000082: 
032301,000083:                                                                                                 #        MPAC CONTAINS THE POSITION VECTOR OF THE SUN RELATIVE TO THE EARTH
032302,000084:                                                                                                 #        AT TIME INPUT BY THE USER IN METERS X B-38.
032303,000085: 
032304,000086:                                                                                                 #  SUBROUTINES USED
032305,000087: 
032306,000088:                                                                                                 #        NONE
032307,000089: 
032308,000090:                                                                                                 #  REMARKS
032309,000091: 
032310,000092:                                                                                                 #        THE VAC AREA IS USED FOR STORAGE OF INTERMEDIATE AND FINAL RESULTS
032311,000093:                                                                                                 #        OF COMPUTATIONS.
032312,000094: 
032313,000095:                                                                                                 #        S1, X1 AND X2 ARE USED BY THESE SUBROUTINES.
032314,000096:                                                                                                 #        PRELAUNCH ERASABLE DATA LOAD ARE ONLY ERASABLE STORAGE USED BY
032315,000097:                                                                                                 #        THESE SUBROUTINES.
032316,000098:                                                                                                 #        RESTARTS DURING OPERATION OF THESE SUBROUTINES MUST BE HANDLED BY
032317,000099:                                                                                                 #        THE USER.
032318,000100: 
032319,000101: 36,2502                                          BANK     36                                    
032320,000102: 26,2000                                          SETLOC   EPHEM                                 
032321,000103: 26,2000                                          BANK                                           
032322,000104: 
032323,000105: 26,2110                                          COUNT*   $$/EPHEM                              
032324,000106: 26,2110  0003777                                 EBANK=   END-E7                                
032325,000107: 26,2110           77774        LSPOS             AXT,2                                          #  COMPUTES POSITION VECTORS OF BOTH THE
032326,000108: 26,2111           54161                                   RESA                                  #  SUN AND THE MOON.  THE POSITION VECTOR
032327,000109: 26,2112           52170                          AXT,1    GOTO                                  #  OF THE SUN IS STORED IN 2D OF THE VAC
032328,000110: 26,2113           54143                                   RES                                   #  AREA.  THE POSITION VECTOR OF THE MOON
032329,000111: 26,2114           54126                                   LSTIME                                #  IS STORED IN MPAC.
032330,000112: 26,2115           52170        LUNPOS            AXT,1    GOTO                                  #  COMPUTES THE POSITION VECTOR OF THE MOON
032331,000113: 26,2116           54162                                   REM                                   #  AND STORES IT IN MPAC.
032332,000114: 26,2117           54126                                   LSTIME                                
032333,000115:                                                                                                 # # Page 738
032334,000116: 26,2120           52170        LUNVEL            AXT,1    GOTO                                  #  COMPUTES THE VELOCITY VECTOR OF THE MOON
032335,000117: 26,2121           54173                                   VEM                                   #  AND STORES IT IN MPAC.
032336,000118: 26,2122           54126                                   LSTIME                                
032337,000119: 26,2123           76020        SOLPOS            STQ      AXT,1                                 #  COMPUTES THE POSITION VECTOR OF THE SUN
032338,000120: 26,2124           00047                                   X2                                    #  AND STORES IT IN MPAC.
032339,000121: 26,2125           54143                                   RES                                   
032340,000122: 26,2126           54201        LSTIME            SETPD    SR                                    
032341,000123: 26,2127           00001                                   0D                                    
032342,000124: 26,2130           20617                                   14D                                   
032343,000125: 26,2131           57571                          TAD      DCOMP                                 
032344,000126: 26,2132           01707                                   TEPHEM                                
032345,000127: 26,2133           57571                          TAD      DCOMP                                 
032346,000128: 26,2134           02034                                   TIMEMO                                
032347,000129: 26,2135           66261                          SL       SSP                                   
032348,000130: 26,2136           20221                                   16D                                   
032349,000131: 26,2137           00051                                   S1                                    
032350,000132: 26,2140           00006                                   6D                                    
032351,000133: 26,2141           77650                          GOTO                                           
032352,000134: 26,2142           00046                                   X1                                    
032353,000135: 26,2143           41206        RES               PUSH     DMP                                   #                                     PD- 2
032354,000136: 26,2144           02147                                   OMEGAES                               
032355,000137: 26,2145           71406                          PUSH     COS                                   #                                     PD- 4
032356,000138: 26,2146           65361                          VXSC     PDDL                                  #                                     PD- 8
032357,000139: 26,2147           02133                                   RESO                                  
032358,000140: 26,2150           63356                          SIN      PDVL                                  #                                     PD-10
032359,000141: 26,2151           02133                                   RESO                                  
032360,000142: 26,2152           53406                          PUSH     UNIT                                  #                                     PD-16
032361,000143: 26,2153           53435                          VXV      UNIT                                  
032362,000144: 26,2154           02141                                   VESO                                  
032363,000145: 26,2155           76435                          VXV      VSL1                                  #                                     PD-10
032364,000146: 26,2156           53361                          VXSC     VAD                                   #                                     PD-02
032365,000147: 26,2157           52172                          VSL1     GOTO                                  #  RES IN METERS X B-38 IN MPAC.
032366,000148: 26,2160           00047                                   X2                                    
032367,000149: 26,2161           14003        RESA              STODL    2D                                    #  RES IN METERS X B-38 IN 2D OF VAC. PD- 0
032368,000150: 26,2162           63370        REM               AXT,1    PDVL                                  #                                     PD- 2
032369,000151: 26,2163           00066                                   54D                                   
032370,000152: 26,2164           02037                                   VECOEM                                
032371,000153: 26,2165           52761        REMA              VXSC     VAD*                                  
032372,000154: 26,2166           00001                                   0D                                    
032373,000155: 26,2167           02133                                   VECOEM     +60D,1                     
032374,000156: 26,2170           72500                          TIX,1    VSL2                                  #  REM IN METERS X B-29 IN MPAC.
032375,000157: 26,2171           54165                                   REMA                                  
032376,000158: 26,2172           77616                          RVQ                                            
032377,000159: 26,2173           65370        VEM               AXT,1    PDDL                                  #                                     PD- 2
032378,000160: 26,2174           00060                                   48D                                   
032379,000161: 26,2175           14214                                   NINEB4                                
032380,000162: 26,2176           74206                          PUSH     VXSC                                  #                                     PD- 4
032381,000163: 26,2177           02037                                   VECOEM                                
032382,000164: 26,2200           77761        VEMA              VXSC                                           
032383,000165: 26,2201           00001                                   0D                                    
032384,000166:                                                                                                 # # Page 739
032385,000167: 26,2202           14005                          STODL    4D                                    #                                     PD- 2
032386,000168: 26,2203           41425                          DSU      PUSH                                  #                                     PD- 4
032387,000169: 26,2204           14216                                   ONEB4                                 
032388,000170: 26,2205           53357                          VXSC*    VAD                                   
032389,000171: 26,2206           02125                                   VECOEM     +54D,1                     
032390,000172: 26,2207           00005                                   4D                                    
032391,000173: 26,2210           72500                          TIX,1    VSL2                                  #  VEM IN METERS/CS X B-7 IN MPAC.
032392,000174: 26,2211           54200                                   VEMA                                  
032393,000175: 26,2212           77616                          RVQ                                            
032394,000176: 26,2213           22000 00000  NINEB4            2DEC     9.0        B-4                        
032395,000177: 26,2215           02000 00000  ONEB4             2DEC     1.0        B-4                        

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