GAP: ASSEMBLE REVISION 072 OF AGC PROGRAM ARTEMIS BY NASA 2021114-011 11:40 FEB. 26, 1971Note that the date is the date of the printout, not the date of the program revision.
Source Code
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These source-code files were obtained by digitally photographing
an Artemis 72 (Apollo 15-17 Command Module) program listing from a private
collection and then
modifying pre-existing Comanche 55 (Apollo 11) source files to
incorporate changes. Photography was by Ron Burkey, and transcription
was performed by a team of volunteers. Note that the page images
presented online are of reduced quality, and that additional images
may be 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 072 OF AGC PROGRAM ARTEMIS BY NASA 2021114-011 11:40 FEB. 26, 1971Note that the date is the date of the printout, not the date of the program revision. |
035108,000002: ## Copyright: Public domain.
035109,000003: ## Filename: LUNAR_AND_SOLAR_EPHEMERIDES_SUBROUTINES.agc
035110,000004: ## Purpose: Part of the source code for Artemis (i.e., Colossus 3),
035111,000005: ## build 072. This is for the Command Module's (CM)
035112,000006: ## Apollo Guidance Computer (AGC), for
035113,000007: ## Apollo 15-17.
035114,000008: ## Assembler: yaYUL
035115,000009: ## Contact: Jim Lawton <jim DOT lawton AT gmail DOT com>
035116,000010: ## Website: www.ibiblio.org/apollo/index.html
035117,000011: ## Page Scans: www.ibiblio.org/apollo/ScansForConversion/Artemis072/
035118,000012: ## Mod history: 2009-08-11 JL Adapted from corresponding Comanche 055 file.
035119,000013: ## 2010-02-20 RSB Un-##'d this header.
035120,000014: ## 2017-02-05 RSB Proofed comment text by diff'ing vs Comanche 55
035121,000015: ## and corrected errors found.
035122,000016:
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Page 789 |
035124,000018:
035125,000019: # LUNAR AND SOLAR EPHEMERIDES SUBROUTINES
035126,000020:
035127,000021: # FUNCTIONAL DESCRIPTION
035128,000022:
035129,000023: # THESE SUBROUTINES ARE USED TO DETERMINE THE POSITION AND VELOCITY
035130,000024: # VECTORS OF THE SUN AND THE MOON RELATIVE TO THE EARTH AT THE
035131,000025: # SPECIFIED GROUND ELAPSED TIME INPUT BY THE USER.
035132,000026:
035133,000027: # THE POSITION OF THE MOON IS STORED IN THE COMPUTER IN THE FORM OF
035134,000028: # A NINTH DEGREE POLYNOMIAL APPROXIMATION WHICH IS VALID OVER A 15
035135,000029: # DAY INTERVAL BEGINNING SHORTLY BEFORE LAUNCH. THEREFORE THE TIME
035136,000030: # INPUT BY THE USER SHOULD FALL WITHIN THIS 15 DAY INTERVAL.
035137,000031: #
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The 9th-degree polynomial spoken of here is a pad load, meaning that it is not actually hardcoded into the software. Additional information about calculating the polynomial can be found on the Orbiter NASSP wiki, as well as information about calculation of the solar ephemerides. |
035145,000039:
035146,000040: # LSPOS COMPUTES THE POSITION VECTORS OF THE SUN AND THE MOON.
035147,000041:
035148,000042: # LUNPOS COMPUTES THE POSITION VECTOR OF THE MOON.
035149,000043:
035150,000044: # LUNVEL COMPUTES THE VELOCITY VECTOR OF THE MOON.
035151,000045:
035152,000046: # CALLING SEQUENCE
035153,000047:
035154,000048: # DLOAD CALL
035155,000049: # TIME GROUND ELAPSED TIME
035156,000050: # SUBROUTINE LSPOS OR LUNPOS OR LUNVEL
035157,000051:
035158,000052: # INPUT
035159,000053:
035160,000054: # 1) SPECIFIED GROUND ELAPSED TIME IN CS X B-28 LOADED IN MPAC.
035161,000055:
035162,000056: # 2) TIMEMO - TIME AT THE CENTER OF THE RANGE OVER WHICH THE LUNAR
035163,000057: # POSITION POLYNOMIAL IS VALID IN CS X B-42.
035164,000058:
035165,000059: # 3) VECOEM - VECTOR COEFFICIENTS OF THE LUNAR POSITION POLYNOMIAL
035166,000060: # LOADED IN DESCENDING SEQUENCE IN METERS/CS**N X B-2
035167,000061:
035168,000062: # 4) RESO - POSITION VECTOR OF THE SUN RELATIVE TO THE EARTH AT
035169,000063: # TIMEMO IN METERS X B-38.
035170,000064:
035171,000065: # 5) VESO - VELOCITY VECTOR OF THE SUN RELATIVE TO THE EARTH AT
035172,000066: # TIMEMO IN METERS/CS X B-9.
035173,000067: #
035174,000068: # 6) OMEGAES - ANGULAR VELOCITY OF THE VECTOR RESO AT TIMEMO IN
035175,000069: # REV/CS X B+26.
035176,000070:
035177,000071: # ALL EXCEPT THE FIRST INPUT ARE INCLUDED IN THE PRE-LAUNCH
035178,000072: # ERASABLE DATA LOAD.
035179,000073:
035180,000074: # OUTPUT - LSPOS
035181,000075:
035182,000076: # 1) 2D OF VAC AREA CONTAINS THE POSITION VECTOR OF THE SUN RELATIVE
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Page 790 |
035184,000078: # TO THE EARTH AT TIME INPUT BY THE USER IN METERS X B-38.
035185,000079:
035186,000080: # 2) MPAC CONTAINS THE POSITION VECTOR OF THE MOON RELATIVE TO THE
035187,000081: # EARTH AT TIME INPUT BY THE USER IN METERS X B-29.
035188,000082:
035189,000083: # OUTPUT - LUNPOS
035190,000084:
035191,000085: # MPAC CONTAINS THE POSITION VECTOR OF THE MOON RELATIVE TO THE
035192,000086: # EARTH AT THE TIME INPUT BY USER IN METERS X B-29.
035193,000087:
035194,000088: # OUTPUT - LUNVEL
035195,000089:
035196,000090: # MPAC CONTAINS THE VELOCITY VECTOR OF THE MOON RELATIVE TO THE
035197,000091: # EARTH AT TIME INPUT BY THE USER IN METERS/CS X B-7.
035198,000092:
035199,000093: # SUBROUTINES USED
035200,000094:
035201,000095: # NONE
035202,000096:
035203,000097: # REMARKS
035204,000098:
035205,000099: # THE VAC AREA IS USED FOR STORAGE OF INTERMEDIATE AND FINAL RESULTS
035206,000100: # OF COMPUTATIONS.
035207,000101:
035208,000102: # S1, X1 AND X2 ARE USED BY THESE SUBROUTINES.
035209,000103: # PRELAUNCH ERASABLE DATA LOAD ARE ONLY ERASABLE STORAGE USED BY
035210,000104: # THESE SUBROUTINES.
035211,000105: # RESTARTS DURING OPERATION OF THESE SUBROUTINES MUST BE HANDLED BY
035212,000106: # THE USER.
035213,000107:
035214,000108: 26,2000 SETLOC EPHEM
035215,000109: 26,2000 BANK
035216,000110:
035217,000111: 26,2136 COUNT* $$/EPHEM
035218,000112: 26,2136 0003777 EBANK= WHOCARES
035219,000113: 26,2136 52170 LSPOS AXT,1 GOTO
035220,000114: 26,2137 54163 RES # AREA. THE POSITION VECTOR OF THE MOON
035221,000115: 26,2140 54146 LSTIME # IS STORED IN MPAC.
035222,000116: 26,2141 52170 LUNPOS AXT,1 GOTO # COMPUTES THE POSITION VECTOR OF THE MOON
035223,000117: 26,2142 54201 REM # AND STORES IT IN MPAC.
035224,000118: 26,2143 54146 LSTIME
035225,000119: 26,2144 77770 LUNVEL AXT,1
035226,000120: 26,2145 54212 VEM # AND STORES IT IN MPAC.
035227,000121: 26,2146 54201 LSTIME SETPD SR
035228,000122: 26,2147 00001 0D
035229,000123: 26,2150 20617 14D
035230,000124: 26,2151 57571 TAD DCOMP
035231,000125: 26,2152 01707 TEPHEM
035232,000126: 26,2153 57571 TAD DCOMP
035233,000127: 26,2154 02034 TIMEMO
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Page 791 |
035235,000129: 26,2155 66261 SL SSP
035236,000130: 26,2156 20221 16D
035237,000131: 26,2157 00051 S1
035238,000132: 26,2160 00006 6D
035239,000133: 26,2161 77650 GOTO
035240,000134: 26,2162 00046 X1
035241,000135: 26,2163 41206 RES PUSH DMP # PD- 2
035242,000136: 26,2164 02147 OMEGAES
035243,000137: 26,2165 71406 PUSH COS # PD- 4
035244,000138: 26,2166 65361 VXSC PDDL # PD- 8
035245,000139: 26,2167 02133 RESO
035246,000140: 26,2170 63356 SIN PDVL # PD-10
035247,000141: 26,2171 02133 RESO
035248,000142: 26,2172 53406 PUSH UNIT # PD-16
035249,000143: 26,2173 53435 VXV UNIT
035250,000144: 26,2174 02141 VESO
035251,000145: 26,2175 76435 VXV VSL1 # PD-10
035252,000146: 26,2176 53361 VXSC VAD # PD-02
035253,000147: 26,2177 77772 VSL1
035254,000148: 26,2200 14003 RESA STODL 2D # RES IN METERS X B-38 IN 2D OF VAC. PD- 0
035255,000149: 26,2201 63370 REM AXT,1 PDVL # PD- 2
035256,000150: 26,2202 00066 54D
035257,000151: 26,2203 02037 VECOEM
035258,000152: 26,2204 52761 REMA VXSC VAD*
035259,000153: 26,2205 00001 0D
035260,000154: 26,2206 02133 VECOEM +60D,1
035261,000155: 26,2207 72500 TIX,1 VSL2 # REM IN METERS X B-29 IN MPAC.
035262,000156: 26,2210 54204 REMA
035263,000157: 26,2211 77616 RVQ
035264,000158: 26,2212 65370 VEM AXT,1 PDDL # PD- 2
035265,000159: 26,2213 00060 48D
035266,000160: 26,2214 14233 NINEB4
035267,000161: 26,2215 74206 PUSH VXSC # PD- 4
035268,000162: 26,2216 02037 VECOEM
035269,000163: 26,2217 77761 VEMA VXSC
035270,000164: 26,2220 00001 0D
035271,000165: 26,2221 14005 STODL 4D # PD- 2
035272,000166: 26,2222 41425 DSU PUSH # PD- 4
035273,000167: 26,2223 31771 ONEB4
035274,000168: 26,2224 53357 VXSC* VAD
035275,000169: 26,2225 02125 VECOEM +54D,1
035276,000170: 26,2226 00005 4D
035277,000171: 26,2227 72500 TIX,1 VSL2 # VEM IN METERS/CS X B-7 IN MPAC.
035278,000172: 26,2230 54217 VEMA
035279,000173: 26,2231 77616 RVQ
035280,000174: 26,2232 22000 00000 NINEB4 2DEC 9.0 B-4
035281,000175: 26,2234 34,3770 ONEB4 EQUALS DP2(-4) # 1 B-4
035282,000176:
End of include-file LUNAR_AND_SOLAR_EPHEMERIDES_SUBROUTINES.agc. Parent file is MAIN.agc