Source Code
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These source-code files were derived from scans of the
Colossus 237 (Apollo 8 Command Module) program listing from the private collection of original
AGC developer Fred Martin. Scanning was by Ron Burkey. Pre-existing Colossus 249
(Apollo 9 CM) source files were used as a template, and changes between Colossus 249
and Colossus 237 were manually transcribed by a team of volunteers. 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, 1968Note that the date is the date of the printout, not the date of the program revision. |
032362,000002: ## Copyright: Public domain.
032363,000003: ## Filename: LUNAR_AND_SOLAR_EPHEMERIDES_SUBROUTINES.agc
032364,000004: ## Purpose: Part of the source code for Colossus build 237.
032365,000005: ## This is for the Command Module's (CM) Apollo Guidance
032366,000006: ## Computer (AGC), for Apollo 8.
032367,000007: ## Assembler: yaYUL
032368,000008: ## Contact: Jim Lawton <jim DOT lawton AT gmail DOT com>
032369,000009: ## Website: www.ibiblio.org/apollo/index.html
032370,000010: ## Page Scans: www.ibiblio.org/apollo/ScansForConversion/Colossus237/
032371,000011: ## Mod history: 2011-02-27 JL Adapted from corresponding Colossus 249 file.
032372,000012: ## 2016-12-31 RSB Proofed comment text using octopus/ProoferComments,
032373,000013: ## and corrected errors found.
032374,000014:
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Page 736 |
032376,000016: # LUNAR AND SOLAR EPHEMERIDES SUBROUTINES
032377,000017:
032378,000018: # FUNCTIONAL DESCRIPTION
032379,000019:
032380,000020: # THESE SUBROUTINES ARE USED TO DETERMINE THE POSITION AND VELOCITY
032381,000021: # VECTORS OF THE SUN AND THE MOON RELATIVE TO THE EARTH AT THE
032382,000022: # SPECIFIED GROUND ELAPSED TIME INPUT BY THE USER.
032383,000023:
032384,000024: # THE POSITION OF THE MOON IS STORED IN THE COMPUTER IN THE FORM OF
032385,000025: # A NINTH DEGREE POLYNOMIAL APPROXIMATION WHICH IS VALID OVER A 15
032386,000026: # DAY INTERVAL BEGINNING SHORTLY BEFORE LAUNCH. THEREFORE THE TIME
032387,000027: # INPUT BY THE USER SHOULD FALL WITHIN THIS 15 DAY INTERVAL.
032388,000028:
032389,000029: # LSPOS COMPUTES THE POSITION VECTORS OF THE SUN AND THE MOON.
032390,000030:
032391,000031: # LUNPOS COMPUTES THE POSITION VECTOR OF THE MOON.
032392,000032:
032393,000033: # LUNVEL COMPUTES THE VELOCITY VECTOR OF THE MOON.
032394,000034:
032395,000035: # SOLPOS COMPUTES THE POSITION VECTOR OF THE SUN.
032396,000036:
032397,000037: # CALLING SEQUENCE
032398,000038:
032399,000039: # DLOAD CALL
032400,000040: # TIME GROUND ELAPSED TIME
032401,000041: # SUBROUTINE LSPOS OR LUNPOS OR LUNVEL OR SOLPOS
032402,000042:
032403,000043: # INPUT
032404,000044:
032405,000045: # 1) SPECIFIED GROUND ELAPSED TIME IN CS X B-28 LOADED IN MPAC.
032406,000046:
032407,000047: # 2) TIMEMO - TIME AT THE CENTER OF THE RANGE OVER WHICH THE LUNAR
032408,000048: # POSITION POLYNOMIAL IS VALID IN CS X B-42.
032409,000049:
032410,000050: # 3) VECOEM - VECTOR COEFFICIENTS OF THE LUNAR POSITION POLYNOMIAL
032411,000051: # LOADED IN DESCENDING SEQUENCE IN METERS/CS**N X B-2
032412,000052:
032413,000053: # 4) RESO - POSITION VECTOR OF THE SUN RELATIVE TO THE EARTH AT
032414,000054: # TIMEMO IN METERS X B-38.
032415,000055:
032416,000056: # 5) VESO - VELOCITY VECTOR OF THE SUN RELATIVE TO THE EARTH AT
032417,000057: # TIMEMO IN METERS/CS X B-9.
032418,000058:
032419,000059: # 6) OMEGAES - ANGULAR VELOCITY OF THE VECTOR RESO AT TIMEMO IN
032420,000060: # REV/CS X B+26.
032421,000061:
032422,000062: # ALL EXCEPT THE FIRST INPUT ARE INCLUDED IN THE PRE-LAUNCH
032423,000063: # ERASABLE DATA LOAD.
032424,000064:
032425,000065: # OUTPUT - LSPOS
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Page 737 |
032427,000067: # 1) 2D OF VAC AREA CONTAINS THE POSITION VECTOR OF THE SUN RELATIVE
032428,000068: # TO THE EARTH AT TIME INPUT BY THE USER IN METERS X B-38.
032429,000069:
032430,000070: # 2) MPAC CONTAINS THE POSITION VECTOR OF THE MOON RELATIVE TO THE
032431,000071: # EARTH AT TIME INPUT BY THE USER IN METERS X B-29.
032432,000072:
032433,000073: # OUTPUT - LUNPOS
032434,000074:
032435,000075: # MPAC CONTAINS THE POSITION VECTOR OF THE MOON RELATIVE TO THE
032436,000076: # EARTH AT THE TIME INPUT BY USER IN METERS X B-29.
032437,000077:
032438,000078: # OUTPUT - LUNVEL
032439,000079:
032440,000080: # MPAC CONTAINS THE VELOCITY VECTOR OF THE MOON RELATIVE TO THE
032441,000081: # EARTH AT TIME INPUT BY THE USER IN METERS/CS X B-7.
032442,000082:
032443,000083: # OUTPUT - SOLPOS
032444,000084:
032445,000085: # MPAC CONTAINS THE POSITION VECTOR OF THE SUN RELATIVE TO THE EARTH
032446,000086: # AT TIME INPUT BY THE USER IN METERS X B-38.
032447,000087:
032448,000088: # SUBROUTINES USED
032449,000089:
032450,000090: # NONE
032451,000091:
032452,000092: # REMARKS
032453,000093:
032454,000094: # THE VAC AREA IS USED FOR STORAGE OF INTERMEDIATE AND FINAL RESULTS
032455,000095: # OF COMPUTATIONS.
032456,000096:
032457,000097: # S1, X1 AND X2 ARE USED BY THESE SUBROUTINES.
032458,000098: # PRELAUNCH ERASABLE DATA LOAD ARE ONLY ERASABLE STORAGE USED BY
032459,000099: # THESE SUBROUTINES.
032460,000100: # RESTARTS DURING OPERATION OF THESE SUBROUTINES MUST BE HANDLED BY
032461,000101: # THE USER.
032462,000102:
032463,000103: 36,2502 BANK 36
032464,000104: 26,2000 SETLOC EPHEM
032465,000105: 26,2000 BANK
032466,000106:
032467,000107: 26,2110 COUNT* $$/EPHEM
032468,000108: 26,2110 0003777 EBANK= END-E7
032469,000109: 26,2110 77774 LSPOS AXT,2 # COMPUTES POSITION VECTORS OF BOTH THE
032470,000110: 26,2111 54161 RESA # SUN AND THE MOON. THE POSITION VECTOR
032471,000111: 26,2112 52170 AXT,1 GOTO # OF THE SUN IS STORED IN 2D OF THE VAC
032472,000112: 26,2113 54143 RES # AREA. THE POSITION VECTOR OF THE MOON
032473,000113: 26,2114 54126 LSTIME # IS STORED IN MPAC.
032474,000114: 26,2115 52170 LUNPOS AXT,1 GOTO # COMPUTES THE POSITION VECTOR OF THE MOON
032475,000115: 26,2116 54162 REM # AND STORES IT IN MPAC.
032476,000116: 26,2117 54126 LSTIME
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Page 738 |
032478,000118: 26,2120 52170 LUNVEL AXT,1 GOTO # COMPUTES THE VELOCITY VECTOR OF THE MOON
032479,000119: 26,2121 54173 VEM # AND STORES IT IN MPAC.
032480,000120: 26,2122 54126 LSTIME
032481,000121: 26,2123 76020 SOLPOS STQ AXT,1 # COMPUTES THE POSITION VECTOR OF THE SUN
032482,000122: 26,2124 00047 X2 # AND STORES IT IN MPAC.
032483,000123: 26,2125 54143 RES
032484,000124: 26,2126 54201 LSTIME SETPD SR
032485,000125: 26,2127 00001 0D
032486,000126: 26,2130 20617 14D
032487,000127: 26,2131 57571 TAD DCOMP
032488,000128: 26,2132 01707 TEPHEM
032489,000129: 26,2133 57571 TAD DCOMP
032490,000130: 26,2134 02034 TIMEMO
032491,000131: 26,2135 66261 SL SSP
032492,000132: 26,2136 20221 16D
032493,000133: 26,2137 00051 S1
032494,000134: 26,2140 00006 6D
032495,000135: 26,2141 77650 GOTO
032496,000136: 26,2142 00046 X1
032497,000137: 26,2143 41206 RES PUSH DMP # PD- 2
032498,000138: 26,2144 02147 OMEGAES
032499,000139: 26,2145 71406 PUSH COS # PD- 4
032500,000140: 26,2146 65361 VXSC PDDL # PD- 8
032501,000141: 26,2147 02133 RESO
032502,000142: 26,2150 63356 SIN PDVL # PD-10
032503,000143: 26,2151 02133 RESO
032504,000144: 26,2152 53406 PUSH UNIT # PD-16
032505,000145: 26,2153 53435 VXV UNIT
032506,000146: 26,2154 02141 VESO
032507,000147: 26,2155 76435 VXV VSL1 # PD-10
032508,000148: 26,2156 53361 VXSC VAD # PD-02
032509,000149: 26,2157 52172 VSL1 GOTO # RES IN METERS X B-38 IN MPAC.
032510,000150: 26,2160 00047 X2
032511,000151: 26,2161 14003 RESA STODL 2D # RES IN METERS X B-38 IN 2D OF VAC. PD- 0
032512,000152: 26,2162 63370 REM AXT,1 PDVL # PD- 2
032513,000153: 26,2163 00066 54D
032514,000154: 26,2164 02037 VECOEM
032515,000155: 26,2165 52761 REMA VXSC VAD*
032516,000156: 26,2166 00001 0D
032517,000157: 26,2167 02133 VECOEM +60D,1
032518,000158: 26,2170 72500 TIX,1 VSL2 # REM IN METERS X B-29 IN MPAC.
032519,000159: 26,2171 54165 REMA
032520,000160: 26,2172 77616 RVQ
032521,000161: 26,2173 65370 VEM AXT,1 PDDL # PD- 2
032522,000162: 26,2174 00060 48D
032523,000163: 26,2175 14214 NINEB4
032524,000164: 26,2176 74206 PUSH VXSC # PD- 4
032525,000165: 26,2177 02037 VECOEM
032526,000166: 26,2200 77761 VEMA VXSC
032527,000167: 26,2201 00001 0D
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Page 739 |
032529,000169: 26,2202 14005 STODL 4D # PD- 2
032530,000170: 26,2203 41425 DSU PUSH # PD- 4
032531,000171: 26,2204 14216 ONEB4
032532,000172: 26,2205 53357 VXSC* VAD
032533,000173: 26,2206 02125 VECOEM +54D,1
032534,000174: 26,2207 00005 4D
032535,000175: 26,2210 72500 TIX,1 VSL2 # VEM IN METERS/CS X B-7 IN MPAC.
032536,000176: 26,2211 54200 VEMA
032537,000177: 26,2212 77616 RVQ
032538,000178: 26,2213 22000 00000 NINEB4 2DEC 9.0 B-4
032539,000179: 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