Source Code

These source-code files were obtained by digitally photographing an Artemis 72 program listing from a private collection and then modifying pre-existing Comanche 55 (Apollo 11) source files to incorporate changes. 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, 1971

	THIS AGC PROGRAM SHALL ALSO BE REFERRED TO AS
				COLOSSUS 3
	THIS PROGRAM IS INTENDED FOR USE IN THE CM AS SPECIFIED
	IN REPORT R-577.  THIS PROGRAM WAS PREPARED UNDER OSR
	PROJECT 55-23890, SPONSORED BY THE MANNED SPACECRAFT
	CENTER OF THE NATIONAL AERONAUTICS AND SPACE
	ADMINISTRATION THROUGH CONTRACT NAS 9-4065 WITH THE
	CHARLES STARK DRAPER LABORATORY, MASSACHUSETTS INSTITUTE OF
	TECHNOLOGY, CAMBRIDGE, MASS.

052654,000002:                                                                                                 #  Copyright:     Public domain.
052655,000003:                                                                                                 #  Filename:      LATITUDE_LONGITUDE_SUBROUTINES.agc
052656,000004:                                                                                                 #  Purpose:       Part of the source code for Artemis (i.e., Colossus 3),
052657,000005:                                                                                                 #                 build 072.  This is for the Command Module's (CM)
052658,000006:                                                                                                 #                 Apollo Guidance Computer (AGC), we believe for
052659,000007:                                                                                                 #                 Apollo 15-17.
052660,000008:                                                                                                 #  Assembler:     yaYUL
052661,000009:                                                                                                 #  Contact:       Sergio Navarro <sergionavarrog@gmail.com>
052662,000010:                                                                                                 #  Website:       www.ibiblio.org/apollo/index.html
052663,000011:                                                                                                 #  Page scans:    www.ibiblio.org/apollo/ScansForConversion/Artemis072/
052664,000012:                                                                                                 #  Mod history:   2009-09-03 SN   Adapted from corresponding Comanche 055 file.
052665,000013:                                                                                                 #                 2009-09-04 JL   Fixed typos.
052666,000014:                                                                                                 #                 2010-02-20 RSB  Un-##'d this header.
052667,000015:                                                                                                 #                 2010-04-13 JL   Fixed a typo (' instead of #).
052668,000016:                                                                                                 #                 2010-08-15 JL   Fixed indentation.
052669,000017: 
052670,000018:                                                                                                 # # Page 1236
052671,000019:                                                                                                 #  SUBROUTINE TO CONVERT RAD VECTOR AT GIVEN TIME TO LAT,LONG AND ALT
052672,000020: 
052673,000021:                                                                                                 #  CALLING SEQUENCE
052674,000022: 
052675,000023:                                                                                                 #         L-1     CALL
052676,000024:                                                                                                 #         L               LAT-LONG
052677,000025: 
052678,000026:                                                                                                 #  SUBROUTINES USED
052679,000027: 
052680,000028:                                                                                                 #         R-TO-RP, ARCTAN, SETGAMMA, SETRE
052681,000029: 
052682,000030:                                                                                                 #  ERASABLE INIT. REQ.
052683,000031: 
052684,000032:                                                                                                 #         AXO, -AYO, AZO, TEPHEM (SET AT LAUNCH TIME)
052685,000033:                                                                                                 #         ALPHAV = POSITION VECTOR METERS B-29
052686,000034:                                                                                                 #         MPAC -- TIME (CSECS B-28)
052687,000035:                                                                                                 #         ERADFLAG =1, TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
052688,000036:                                                                                                 #         LUNAFLAG=0 FOR EARTH, 1 FOR MOON
052689,000037: 
052690,000038:                                                                                                 #  OUTPUT
052691,000039: 
052692,000040:                                                                                                 #         LATITUDE IN LAT         (REVS. B-0)
052693,000041:                                                                                                 #         LONGITUDE IN LONG       (REVS. B-0)
052694,000042:                                                                                                 #         ALTITUDE IN ALT METERS B-29
052695,000043: 
052696,000044: 13,2000                                          SETLOC   LATLONG                               
052697,000045: 13,2000                                          BANK                                           
052698,000046: 
052699,000047: 13,2453                                          COUNT*   $$/LT-LG                              
052700,000048: 13,2453  E4,1551                                 EBANK=   ALPHAV                                
052701,000049: 13,2453           40220        LAT-LONG          STQ      SETPD                                 
052702,000050: 13,2454           02241                                   INCORPEX                              
052703,000051: 13,2455           00001                                   0D                                    
052704,000052: 13,2456           24007                          STOVL    6D                                    #  SAVE TIME IN 6-7D FOR R-TO-RP
052705,000053: 13,2457           02152                                   ALPHAV                                
052706,000054: 13,2460           51406                          PUSH     ABVAL                                 #  0-5D= R FOR R-TO-RP
052707,000055: 13,2461           16301                          STODL    ALPHAM                                #  ABS. VALUE OF R FOR ALT FORMULA BELOW
052708,000056: 13,2462           11762                                   ZEROVEC                               #  SET MPAC=0 FOR EARTH, NON-ZERO FOR MOON
052709,000057: 13,2463           71414                          BOFF     COS                                   #  USE COS(0) TO GET NON-ZERO IN MPAC
052710,000058: 13,2464           01743                                   LUNAFLAG                              #  0=EARTH,1=MOON
052711,000059: 13,2465           26466                                   CALLRTRP                              
052712,000060: 13,2466           77624        CALLRTRP          CALL                                           
052713,000061: 13,2467           55370                                   R-TO-RP                               #  RP VECTOR CONVERTED FROM R B-29
052714,000062: 13,2470           77656                          UNIT                                           #  UNIT RP B-1
052715,000063: 13,2471           36152                          STCALL   ALPHAV                                #  U2= 1/2 SINL FOR SETRE SUBR BELOW
052716,000064: 13,2472           35766                                   SETGAMMA                              #   SET GAMMA=B2/A2 FOR EARTH, =1 FOR MOON
052717,000065: 13,2473           77624                          CALL                                           #   SCALED B-1.
052718,000066: 13,2474           26654                                   SETRE                                 #  CALC RE METERS B-29
052719,000067: 13,2475           63545                          DLOAD    DSQ                                   
052720,000068: 13,2476           02152                                   ALPHAV                                
052721,000069: 13,2477           63525                          PDDL     DSQ                                   
052722,000070: 13,2500           02154                                   ALPHAV     +2                         
052723,000071: 13,2501           75415                          DAD      SQRT                                  
052724,000072: 13,2502           76405                          DMP      SL1R                                  
052725,000073:                                                                                                 # # Page 1237
052726,000074: 13,2503           00011                                   GAMRP                                 
052727,000075: 13,2504           14021                          STODL    COSTH                                 #  COS(LAT) B-1
052728,000076: 13,2505           02156                                   ALPHAV     +4                         
052729,000077: 13,2506           34023                          STCALL   SINTH                                 #  SIN(LAT) B-1
052730,000078: 13,2507           26614                                   ARCTAN                                
052731,000079: 13,2510           14747                          STODL    LAT                                   #  LAT B0
052732,000080: 13,2511           02152                                   ALPHAV                                
052733,000081: 13,2512           14021                          STODL    COSTH                                 #  COS(LONG) B-1
052734,000082: 13,2513           02154                                   ALPHAV     +2                         
052735,000083: 13,2514           34023                          STCALL   SINTH                                 #  SIN(LONG) B-1
052736,000084: 13,2515           26614                                   ARCTAN                                
052737,000085: 13,2516           14751                          STODL    LONG                                  #  LONG. REVS B-0 IN RANGE -1/2 TO 1/2
052738,000086: 13,2517           02301                                   ALPHAM                                
052739,000087: 13,2520           77625                          DSU                                            #  ALT= R-RE METERS B-29
052740,000088: 13,2521           02240                                   ERADM                                 
052741,000089: 13,2522           34753                          STCALL   ALT                                   #  EXIT WITH ALT METERS B-29
052742,000090: 13,2523           02241                                   INCORPEX                              
052743,000091: 
052744,000092:                                                                                                 # # Page 1238
052745,000093:                                                                                                 #  SUBROUTINE TO CONVERT LAT,LONG.ALT AT GIVEN TIME TO RADIUS VECTOR
052746,000094: 
052747,000095:                                                                                                 #  CALLING SEQUENCE
052748,000096: 
052749,000097:                                                                                                 #         L-1     CALL
052750,000098:                                                                                                 #         L               LALOTORV
052751,000099: 
052752,000100:                                                                                                 #  SUBROUTINES USED
052753,000101: 
052754,000102:                                                                                                 #         SETGAMMA, SETRE, RP-TO-R
052755,000103: 
052756,000104:                                                                                                 #  ERASABLE INIT. REQ.
052757,000105: 
052758,000106:                                                                                                 #         AXO, AYO, AZO, TEPHEM  SET AT LAUNCH TIME
052759,000107:                                                                                                 #         LAT -- LATITUDE         (REVS B0)
052760,000108:                                                                                                 #         LONG -- LONGITUDE       (REVS B0)
052761,000109:                                                                                                 #         ALT -- ALTITUDE         (METERS) B-29
052762,000110:                                                                                                 #         MPAC -- TIME            (CSECS B-28)
052763,000111:                                                                                                 #         ERADFLAG =1 TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
052764,000112:                                                                                                 #         LUNAFLAG=0 FOR EARTH, 1 FOR MOON
052765,000113: 
052766,000114:                                                                                                 #  OUTPUT
052767,000115: 
052768,000116:                                                                                                 #         R-VECTOR IN ALPHAV (METERS B-29)
052769,000117: 
052770,000118: 13,2524           40220        LALOTORV          STQ      SETPD                                 #  LAT,LONG,ALT TO R VECTOR
052771,000119: 13,2525           02241                                   INCORPEX                              
052772,000120: 13,2526           00001                                   0D                                    
052773,000121: 13,2527           34007                          STCALL   6D                                    #  6-7D = TIME FOR RP-TO-R
052774,000122: 13,2530           35766                                   SETGAMMA                              #  GAMMA = B2/A2 FOR EARTH, 1 FOR MOON B-1
052775,000123: 13,2531           73545                          DLOAD    SIN                                   #                    COS(LONG)COS(LAT) IN MPAC
052776,000124: 13,2532           00747                                   LAT                                   #         UNIT  RP = SIN(LONG)COS(LAT)    2-3D
052777,000125: 13,2533           65275                          DMPR     PDDL                                  #  PD 2              GAMMA*SIN(LAT)       0-1D
052778,000126: 13,2534           00011                                   GAMRP                                 
052779,000127: 13,2535           00747                                   LAT                                   #             0-1D = GAMMA*SIN(LAT) B-2
052780,000128: 13,2536           65346                          COS      PDDL                                  #  PD4        2-3D = COS(LAT) B-1 TEMPORARILY
052781,000129: 13,2537           00751                                   LONG                                  
052782,000130: 13,2540           57356                          SIN      DMPR                                  #  PD 2
052783,000131: 13,2541           71525                          PDDL     COS                                   #  PD 4       2-3D = SIN(LONG)COS(LAT) B-2
052784,000132: 13,2542           00747                                   LAT                                   
052785,000133: 13,2543           71525                          PDDL     COS                                   #  PD 6       4-5D = COS(LAT) B-1 TEMPORARILY
052786,000134: 13,2544           00751                                   LONG                                  
052787,000135: 13,2545           55475                          DMPR     VDEF                                  #  PD4        MPAC = COS(LONG)COS(LAT) B-2
052788,000136: 13,2546           41456                          UNIT     PUSH                                  #  0-5D = UNIT RP FOR RP-TO-R SUBR.
052789,000137: 13,2547           36152                          STCALL   ALPHAV                                #  ALPHAV +4= SINL FOR SETRE SUBR.
052790,000138: 13,2550           26654                                   SETRE                                 #  RE METERS B-29
052791,000139: 13,2551           43145                          DLOAD    BOFF                                  #  SET MPAC = 0 FOR EARTH, NON-ZERO FOR MOON
052792,000140: 13,2552           11762                                   ZEROVEC                               
052793,000141: 13,2553           01743                                   LUNAFLAG                              
052794,000142: 13,2554           26556                                   CALLRPRT                              
052795,000143: 13,2555           77746                          COS                                            #  USE COS(0) TO GET NON-ZERO IN MPAC
052796,000144: 13,2556           77624        CALLRPRT          CALL                                           
052797,000145: 13,2557           55345                                   RP-TO-R                               #  EXIT WITH UNIT R VECTOR IN MPAC
052798,000146: 13,2560           16152                          STODL    ALPHAV                                
052799,000147: 13,2561           02240                                   ERADM                                 
052800,000148:                                                                                                 # # Page 1239
052801,000149: 13,2562           74215                          DAD      VXSC                                  #  (RE + ALT)(UNIT R) METERS B-30
052802,000150: 13,2563           00753                                   ALT                                   
052803,000151: 13,2564           02152                                   ALPHAV                                
052804,000152: 13,2565           77772                          VSL1                                           #  R METERS B-29
052805,000153: 13,2566           36152                          STCALL   ALPHAV                                #  EXIT WITH R IN METERS B-29
052806,000154: 13,2567           02241                                   INCORPEX                              
052807,000155: 
052808,000156:                                                                                                 #  SUBROUTINE TO COMPUTE EARTH RADIUS
052809,000157: 
052810,000158:                                                                                                 #  INPUT
052811,000159: 
052812,000160:                                                                                                 #         1/2 SIN LAT IN ALPHAV +4
052813,000161: 
052814,000162:                                                                                                 #  OUTPUT
052815,000163: 
052816,000164:                                                                                                 #         EARTH RADIUS IN ERADM AND MPAC  (METERS B-29)
052817,000165: 
052818,000166: 13,2570           63545        GETERAD           DLOAD    DSQ                                   
052819,000167: 13,2571           02156                                   ALPHAV     +4                         #  SIN**2(L)
052820,000168: 13,2572           44352                          SL1      BDSU                                  
052821,000169: 13,2573           11760                                   DP1/2                                 #  COS**2(L)
052822,000170: 13,2574           44275                          DMPR     BDSU                                  
052823,000171: 13,2575           26611                                   EE                                    
052824,000172: 13,2576           11760                                   DP1/2                                 
052825,000173: 13,2577           75465                          BDDV     SQRT                                  
052826,000174: 13,2600           26605                                   B2XSC                                 
052827,000175: 13,2601           77622                          SR4R                                           
052828,000176: 13,2602           02240                          STORE    ERADM                                 
052829,000177: 13,2603           77616                          RVQ                                            
052830,000178: 
052831,000179:                                                                                                 #  THE FOLLOWING CONSTANTS WERE COMPUTED WITH A=6378166, B=6356784 METERS
052832,000180:                                                                                                 #  B2XSC = B**2 SCALED B-51
052833,000181:                                                                                                 #  B2/A2 = B**2/A**2  SCALED B-1
052834,000182:                                                                                                 #  EE = (1-B**2/A**2) SCALED B-0
052835,000183: 
052836,000184: 13,2604           00446 00305  B2XSC             2DEC     .0179450689                            #  B**2 SCALED B-51
052837,000185: 13,2606  04,3757               DP1/2             =        XUNIT                                 
052838,000186: 13,2606           17711 05254  B2/A2             2DEC     .9933064884 B-1                        #  GAMMA= B**2/A**2 B-1
052839,000187: 13,2610           00155 25250  EE                2DEC     6.6935116  E-3                        #  (1-B**2/A**2) B-0
052840,000188: 13,2612           00302 17755  ERAD              2DEC     6373338    B-29                       #  PAD RADIUS
052841,000189: 
052842,000190:                                                                                                 # # Page 1240
052843,000191:                                                                                                 #  ARCTAN SUBROUTINE
052844,000192: 
052845,000193:                                                                                                 #  CALLING SEQUENCE
052846,000194: 
052847,000195:                                                                                                 #         SIN THETA IN SINTH B-1
052848,000196:                                                                                                 #         COS THETA IN COSTH B-1
052849,000197:                                                                                                 #         CALL ARCTAN
052850,000198: 
052851,000199:                                                                                                 #  OUTPUT
052852,000200:                                                                                                 #         ARCTAN THETA IN MPAC AND THETA B-0 IN RANGE -1/2 TO +1/2
052853,000201: 
052854,000202: 13,2614           77600        ARCTAN            BOV                                            
052855,000203: 13,2615           26616                                   CLROVFLW                              
052856,000204: 13,2616           63545        CLROVFLW          DLOAD    DSQ                                   
052857,000205: 13,2617           00023                                   SINTH                                 
052858,000206: 13,2620           63525                          PDDL     DSQ                                   
052859,000207: 13,2621           00021                                   COSTH                                 
052860,000208: 13,2622           77615                          DAD                                            
052861,000209: 13,2623           75454                          BZE      SQRT                                  
052862,000210: 13,2624           26642                                   ARCTANXX                              #  ATAN=0/0  SET THETA=0
052863,000211: 13,2625           40065                          BDDV     BOV                                   
052864,000212: 13,2626           00023                                   SINTH                                 
052865,000213: 13,2627           26647                                   ATAN=90                               
052866,000214: 13,2630           67542                          SR1      ASIN                                  
052867,000215: 13,2631           00025                          STORE    THETA                                 
052868,000216: 13,2632           50125                          PDDL     BMN                                   
052869,000217: 13,2633           00021                                   COSTH                                 
052870,000218: 13,2634           26636                                   NEGCOS                                
052871,000219: 13,2635           43545                          DLOAD    RVQ                                   
052872,000220: 13,2636           57545        NEGCOS            DLOAD    DCOMP                                 
052873,000221: 13,2637           43244                          BPL      DAD                                   
052874,000222: 13,2640           26644                                   NEGOUT                                
052875,000223: 13,2641           11760                                   DP1/2                                 
052876,000224: 13,2642           00025        ARCTANXX          STORE    THETA                                 
052877,000225: 13,2643           77616                          RVQ                                            
052878,000226: 
052879,000227: 13,2644           52025        NEGOUT            DSU      GOTO                                  
052880,000228: 13,2645           11760                                   DP1/2                                 
052881,000229: 13,2646           26642                                   ARCTANXX                              
052882,000230: 13,2647           75345        ATAN=90           DLOAD    SIGN                                  
052883,000231: 13,2650           33412                                   LODP1/4                               
052884,000232: 13,2651           00023                                   SINTH                                 
052885,000233: 13,2652           00025                          STORE    THETA                                 
052886,000234: 13,2653           77616                          RVQ                                            
052887,000235: 
052888,000236: 13,2654  04,3761               2DZERO            =        DPZERO                                
052889,000237: 
052890,000238:                                                                                                 # # Page 1241
052891,000239:                                                                                                 #  ..... SETGAMMA SUBROUTINE .....
052892,000240:                                                                                                 #  SUBROUTINE TO SET GAMMA FOR THE LAT-LONG AND LALOTORV SUBROUTINES
052893,000241: 
052894,000242:                                                                                                 #  GAMMA = B**2/A**2 FOR EARTH (B-1)
052895,000243:                                                                                                 #  GAMMA = 1 FOR MOON (B-1)
052896,000244: 
052897,000245:                                                                                                 #  CALLING SEQUENCE
052898,000246:                                                                                                 #         L       CALL
052899,000247:                                                                                                 #         L+1             SETGAMMA
052900,000248: 
052901,000249:                                                                                                 #  INPUT
052902,000250:                                                                                                 #         LUNAFLAG=0 FOR EARTH, =1 FOR MOON
052903,000251: 
052904,000252:                                                                                                 #  OUTPUT
052905,000253:                                                                                                 #         GAMMA IN GAMRP  (B-1)
052906,000254: 
052907,000255: 16,2000                                          SETLOC   LATLONG1                              
052908,000256: 16,2000                                          BANK                                           
052909,000257: 16,3766                                          COUNT*   $$/LT-LG                              
052910,000258: 
052911,000259: 16,3766           43145        SETGAMMA          DLOAD    BOFF                                  #  BRANCH FOR EARTH
052912,000260: 16,3767           26607                                   B2/A2                                 #  EARTH GAMMA
052913,000261: 16,3770           01743                                   LUNAFLAG                              
052914,000262: 16,3771           35774                                   SETGMEX                               
052915,000263: 16,3772           77735                          SLOAD                                          
052916,000264: 16,3773           11760                                   1B1                                   #  MOON GAMMA
052917,000265: 16,3774           00011        SETGMEX           STORE    GAMRP                                 
052918,000266: 16,3775           77616                          RVQ                                            
052919,000267: 16,3776                        GAMRP             =        8D                                    
052920,000268: 13,2000                                          SETLOC   LATLONG                               
052921,000269: 13,2000                                          BANK                                           
052922,000270: 
052923,000271:                                                                                                 # # Page 1242
052924,000272:                                                                                                 #  ..... SETRE SUBROUTINE .....
052925,000273:                                                                                                 #  SUBROUTINE TO SET RE (EARTH OR MOON RADIUS)
052926,000274: 
052927,000275:                                                                                                 #   RE = RM FOR MOON
052928,000276:                                                                                                 #   RE = RREF FOR FIXED EARTH RADIUS OR COMPUTED RF FOR FISCHER ELLIPSOID
052929,000277: 
052930,000278:                                                                                                 #  CALLING SEQUENCE
052931,000279:                                                                                                 #   L     CALL
052932,000280:                                                                                                 #   L+1           SETRE
052933,000281: 
052934,000282:                                                                                                 #  SUBROUTINES USED
052935,000283:                                                                                                 #   GETERAD
052936,000284: 
052937,000285:                                                                                                 #  INPUT
052938,000286:                                                                                                 #   ERADFLAG = 0 FOR FIXED RE, 1 FOR COMPUTED RE
052939,000287:                                                                                                 #   ALPHAV +4 = 1/2 SINL IF GETERAD IS CALLED
052940,000288:                                                                                                 #   LUNAFLAG = 0 FOR EARTH, =1 FOR MOON
052941,000289: 
052942,000290:                                                                                                 #  OUTPUT
052943,000291:                                                                                                 #   ERADM = 504RM FOR MOON (METERS B-29)
052944,000292:                                                                                                 #   ERADM = ERAD OR COMPUTED RE FOR EARTH (METERS B-29)
052945,000293: 
052946,000294: 13,2654           71220        SETRE             STQ      DLOAD                                 
052947,000295: 13,2655           00051                                   SETREX                                
052948,000296: 13,2656           26701                                   504RM                                 
052949,000297: 13,2657           71214                          BON      DLOAD                                 #  BRANCH FOR MOON
052950,000298: 13,2660           01703                                   LUNAFLAG                              
052951,000299: 13,2661           26671                                   TSTRLSRM                              
052952,000300: 13,2662           26613                                   ERAD                                  
052953,000301: 13,2663           45014                          BOFF     CALL                                  #  ERADFLAG=0 FOR FIXED RE, 1 FOR COMPUTED
052954,000302: 13,2664           00742                                   ERADFLAG                              
052955,000303: 13,2665           26667                                   SETRXX                                
052956,000304: 13,2666           26570                                   GETERAD                               
052957,000305: 13,2667           36240        SETRXX            STCALL   ERADM                                 #  EXIT WITH RE OR RM METERS B-29
052958,000306: 13,2670           00051                                   SETREX                                
052959,000307: 13,2671           77214        TSTRLSRM          BON      VLOAD                                 #  ERADFLAG=0, SET R0=RLS
052960,000308: 13,2672           00702                                   ERADFLAG                              #          =1      R0=RM
052961,000309: 13,2673           26667                                   SETRXX                                
052962,000310: 13,2674           02026                                   RLS                                   
052963,000311: 13,2675           64446                          ABVAL    SR2R                                  #  SCALE FROM B-27 TO B-29
052964,000312: 13,2676           77650                          GOTO                                           
052965,000313: 13,2677           26667                                   SETRXX                                
052966,000314: 13,2700  0000051               SETREX            =        S2                                    
052967,000315: 13,2700           00065 01265  504RM             2DEC     1738090    B-29                       #  METERS B-29 (MOON RADIUS)

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