Source Code
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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. |
052685,000002: # Copyright: Public domain.
052686,000003: # Filename: LATITUDE_LONGITUDE_SUBROUTINES.agc
052687,000004: # Purpose: Part of the source code for Artemis (i.e., Colossus 3),
052688,000005: # build 072. This is for the Command Module's (CM)
052689,000006: # Apollo Guidance Computer (AGC), we believe for
052690,000007: # Apollo 15-17.
052691,000008: # Assembler: yaYUL
052692,000009: # Contact: Sergio Navarro <sergionavarrog@gmail.com>
052693,000010: # Website: www.ibiblio.org/apollo/index.html
052694,000011: # Page scans: www.ibiblio.org/apollo/ScansForConversion/Artemis072/
052695,000012: # Mod history: 2009-09-03 SN Adapted from corresponding Comanche 055 file.
052696,000013: # 2009-09-04 JL Fixed typos.
052697,000014: # 2010-02-20 RSB Un-##'d this header.
052698,000015:
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Page 1236 |
052700,000017: # SUBROUTINE TO CONVERT RAD VECTOR AT GIVEN TIME TO LAT,LONG AND ALT
052701,000018:
052702,000019: # CALLING SEQUENCE
052703,000020:
052704,000021: # L-1 CALL
052705,000022: # L LAT-LONG
052706,000023:
052707,000024: # SUBROUTINES USED
052708,000025:
052709,000026: # R-TO-RP, ARCTAN, SETGAMMA, SETRE
052710,000027:
052711,000028: # ERASABLE INIT. REQ.
052712,000029:
052713,000030: # AXO, -AYO, AZO, TEPHEM (SET AT LAUNCH TIME)
052714,000031: # ALPHAV = POSITION VECTOR METERS B-29
052715,000032: # MPAC -- TIME (CSECS B-28)
052716,000033: # ERADFLAG =1, TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
052717,000034: # LUNAFLAG=0 FOR EARTH, 1 FOR MOON
052718,000035:
052719,000036: # OUTPUT
052720,000037:
052721,000038: # LATITUDE IN LAT (REVS. B-0)
052722,000039: # LONGITUDE IN LONG (REVS. B-0)
052723,000040: # ALTITUDE IN ALT METERS B-29
052724,000041:
052725,000042: 13,2000 SETLOC LATLONG
052726,000043: 13,2000 BANK
052727,000044:
052728,000045: 13,2453 COUNT* $$/LT-LG
052729,000046: 13,2453 E4,1551 EBANK= ALPHAV
052730,000047: 13,2453 40220 LAT-LONG STQ SETPD
052731,000048: 13,2454 02241 INCORPEX
052732,000049: 13,2455 00001 0D
052733,000050: 13,2456 24007 STOVL 6D # SAVE TIME IN 6-7D FOR R-TO-RP
052734,000051: 13,2457 02152 ALPHAV
052735,000052: 13,2460 51406 PUSH ABVAL # 0-5D= R FOR R-TO-RP
052736,000053: 13,2461 16301 STODL ALPHAM # ABS. VALUE OF R FOR ALT FORMULA BELOW
052737,000054: 13,2462 11762 ZEROVEC # SET MPAC=0 FOR EARTH, NON-ZERO FOR MOON
052738,000055: 13,2463 71414 BOFF COS # USE COS(0) TO GET NON-ZERO IN MPAC
052739,000056: 13,2464 01743 LUNAFLAG # 0=EARTH,1=MOON
052740,000057: 13,2465 26466 CALLRTRP
052741,000058: 13,2466 77624 CALLRTRP CALL
052742,000059: 13,2467 55370 R-TO-RP # RP VECTOR CONVERTED FROM R B-29
052743,000060: 13,2470 77656 UNIT # UNIT RP B-1
052744,000061: 13,2471 36152 STCALL ALPHAV # U2= 1/2 SINL FOR SETRE SUBR BELOW
052745,000062: 13,2472 35766 SETGAMMA # SET GAMMA=B2/A2 FOR EARTH, =1 FOR MOON
052746,000063: 13,2473 77624 CALL # SCALED B-1.
052747,000064: 13,2474 26654 SETRE # CALC RE METERS B-29
052748,000065: 13,2475 63545 DLOAD DSQ
052749,000066: 13,2476 02152 ALPHAV
052750,000067: 13,2477 63525 PDDL DSQ
052751,000068: 13,2500 02154 ALPHAV +2
052752,000069: 13,2501 75415 DAD SQRT
052753,000070: 13,2502 76405 DMP SL1R
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Page 1237 |
052755,000072: 13,2503 00011 GAMRP
052756,000073: 13,2504 14021 STODL COSTH # COS(LAT) B-1
052757,000074: 13,2505 02156 ALPHAV +4
052758,000075: 13,2506 34023 STCALL SINTH # SIN(LAT) B-1
052759,000076: 13,2507 26614 ARCTAN
052760,000077: 13,2510 14747 STODL LAT # LAT B0
052761,000078: 13,2511 02152 ALPHAV
052762,000079: 13,2512 14021 STODL COSTH # COS(LONG) B-1
052763,000080: 13,2513 02154 ALPHAV +2
052764,000081: 13,2514 34023 STCALL SINTH # SIN(LONG) B-1
052765,000082: 13,2515 26614 ARCTAN
052766,000083: 13,2516 14751 STODL LONG # LONG. REVS B-0 IN RANGE -1/2 TO 1/2
052767,000084: 13,2517 02301 ALPHAM
052768,000085: 13,2520 77625 DSU # ALT= R-RE METERS B-29
052769,000086: 13,2521 02240 ERADM
052770,000087: 13,2522 34753 STCALL ALT # EXIT WITH ALT METERS B-29
052771,000088: 13,2523 02241 INCORPEX
052772,000089:
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Page 1238 |
052774,000091: # SUBROUTINE TO CONVERT LAT,LONG.ALT AT GIVEN TIME TO RADIUS VECTOR
052775,000092:
052776,000093: # CALLING SEQUENCE
052777,000094:
052778,000095: # L-1 CALL
052779,000096: # L LALOTORV
052780,000097:
052781,000098: # SUBROUTINES USED
052782,000099:
052783,000100: # SETGAMMA, SETRE, RP-TO-R
052784,000101:
052785,000102: # ERASABLE INIT. REQ.
052786,000103:
052787,000104: # AXO, AYO, AZO, TEPHEM SET AT LAUNCH TIME
052788,000105: # LAT -- LATITUDE (REVS B0)
052789,000106: # LONG -- LONGITUDE (REVS B0)
052790,000107: # ALT -- ALTITUDE (METERS) B-29
052791,000108: # MPAC -- TIME (CSECS B-28)
052792,000109: # ERADFLAG =1 TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
052793,000110: # LUNAFLAG=0 FOR EARTH, 1 FOR MOON
052794,000111:
052795,000112: # OUTPUT
052796,000113:
052797,000114: # R-VECTOR IN ALPHAV (METERS B-29)
052798,000115:
052799,000116: 13,2524 40220 LALOTORV STQ SETPD # LAT,LONG,ALT TO R VECTOR
052800,000117: 13,2525 02241 INCORPEX
052801,000118: 13,2526 00001 0D
052802,000119: 13,2527 34007 STCALL 6D # 6-7D = TIME FOR RP-TO-R
052803,000120: 13,2530 35766 SETGAMMA # GAMMA = B2/A2 FOR EARTH, 1 FOR MOON B-1
052804,000121: 13,2531 73545 DLOAD SIN # COS(LONG)COS(LAT) IN MPAC
052805,000122: 13,2532 00747 LAT # UNIT RP = SIN(LONG)COS(LAT) 2-3D
052806,000123: 13,2533 65275 DMPR PDDL # PD 2 GAMMA*SIN(LAT) 0-1D
052807,000124: 13,2534 00011 GAMRP
052808,000125: 13,2535 00747 LAT # 0-1D = GAMMA*SIN(LAT) B-2
052809,000126: 13,2536 65346 COS PDDL # PD4 2-3D = COS(LAT) B-1 TEMPORARILY
052810,000127: 13,2537 00751 LONG
052811,000128: 13,2540 57356 SIN DMPR # PD 2
052812,000129: 13,2541 71525 PDDL COS # PD 4 2-3D = SIN(LONG)COS(LAT) B-2
052813,000130: 13,2542 00747 LAT
052814,000131: 13,2543 71525 PDDL COS # PD 6 4-5D = COS(LAT) B-1 TEMPORARILY
052815,000132: 13,2544 00751 LONG
052816,000133: 13,2545 55475 DMPR VDEF # PD4 MPAC = COS(LONG)COS(LAT) B-2
052817,000134: 13,2546 41456 UNIT PUSH # 0-5D = UNIT RP FOR RP-TO-R SUBR.
052818,000135: 13,2547 36152 STCALL ALPHAV # ALPHAV +4= SINL FOR SETRE SUBR.
052819,000136: 13,2550 26654 SETRE # RE METERS B-29
052820,000137: 13,2551 43145 DLOAD BOFF # SET MPAC = 0 FOR EARTH, NON-ZERO FOR MOON
052821,000138: 13,2552 11762 ZEROVEC
052822,000139: 13,2553 01743 LUNAFLAG
052823,000140: 13,2554 26556 CALLRPRT
052824,000141: 13,2555 77746 COS # USE COS(0) TO GET NON-ZERO IN MPAC
052825,000142: 13,2556 77624 CALLRPRT CALL
052826,000143: 13,2557 55345 RP-TO-R # EXIT WITH UNIT R VECTOR IN MPAC
052827,000144: 13,2560 16152 STODL ALPHAV
052828,000145: 13,2561 02240 ERADM
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Page 1239 |
052830,000147: 13,2562 74215 DAD VXSC # (RE + ALT)(UNIT R) METERS B-30
052831,000148: 13,2563 00753 ALT
052832,000149: 13,2564 02152 ALPHAV
052833,000150: 13,2565 77772 VSL1 # R METERS B-29
052834,000151: 13,2566 36152 STCALL ALPHAV # EXIT WITH R IN METERS B-29
052835,000152: 13,2567 02241 INCORPEX
052836,000153:
052837,000154: # SUBROUTINE TO COMPUTE EARTH RADIUS
052838,000155:
052839,000156: # INPUT
052840,000157: 13,2570 '
052841,000158: # 1/2 SIN LAT IN ALPHAV +4
052842,000159:
052843,000160: # OUTPUT
052844,000161:
052845,000162: # EARTH RADIUS IN ERADM AND MPAC (METERS B-29)
052846,000163:
052847,000164: 13,2570 63545 GETERAD DLOAD DSQ
052848,000165: 13,2571 02156 ALPHAV +4 # SIN**2(L)
052849,000166: 13,2572 44352 SL1 BDSU
052850,000167: 13,2573 11760 DP1/2 # COS**2(L)
052851,000168: 13,2574 44275 DMPR BDSU
052852,000169: 13,2575 26611 EE
052853,000170: 13,2576 11760 DP1/2
052854,000171: 13,2577 75465 BDDV SQRT
052855,000172: 13,2600 26605 B2XSC
052856,000173: 13,2601 77622 SR4R
052857,000174: 13,2602 02240 STORE ERADM
052858,000175: 13,2603 77616 RVQ
052859,000176:
052860,000177: # THE FOLLOWING CONSTANTS WERE COMPUTED WITH A=6378166, B=6356784 METERS
052861,000178: # B2XSC = B**2 SCALED B-51
052862,000179: # B2/A2 = B**2/A**2 SCALED B-1
052863,000180: # EE = (1-B**2/A**2) SCALED B-0
052864,000181:
052865,000182: 13,2604 00446 00305 B2XSC 2DEC .0179450689 # B**2 SCALED B-51
052866,000183: 13,2606 04,3757 DP1/2 = XUNIT
052867,000184: 13,2606 17711 05254 B2/A2 2DEC .9933064884 B-1 # GAMMA= B**2/A**2 B-1
052868,000185: 13,2610 00155 25250 EE 2DEC 6.6935116 E-3 # (1-B**2/A**2) B-0
052869,000186: 13,2612 00302 17755 ERAD 2DEC 6373338 B-29 # PAD RADIUS
052870,000187:
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Page 1240 |
052872,000189: # ARCTAN SUBROUTINE
052873,000190:
052874,000191: # CALLING SEQUENCE
052875,000192:
052876,000193: # SIN THETA IN SINTH B-1
052877,000194: # COS THETA IN COSTH B-1
052878,000195: # CALL ARCTAN
052879,000196:
052880,000197: # OUTPUT
052881,000198: # ARCTAN THETA IN MPAC AND THETA B-0 IN RANGE -1/2 TO +1/2
052882,000199:
052883,000200: 13,2614 77600 ARCTAN BOV
052884,000201: 13,2615 26616 CLROVFLW
052885,000202: 13,2616 63545 CLROVFLW DLOAD DSQ
052886,000203: 13,2617 00023 SINTH
052887,000204: 13,2620 63525 PDDL DSQ
052888,000205: 13,2621 00021 COSTH
052889,000206: 13,2622 77615 DAD
052890,000207: 13,2623 75454 BZE SQRT
052891,000208: 13,2624 26642 ARCTANXX # ATAN=0/0 SET THETA=0
052892,000209: 13,2625 40065 BDDV BOV
052893,000210: 13,2626 00023 SINTH
052894,000211: 13,2627 26647 ATAN=90
052895,000212: 13,2630 67542 SR1 ASIN
052896,000213: 13,2631 00025 STORE THETA
052897,000214: 13,2632 50125 PDDL BMN
052898,000215: 13,2633 00021 COSTH
052899,000216: 13,2634 26636 NEGCOS
052900,000217: 13,2635 43545 DLOAD RVQ
052901,000218: 13,2636 57545 NEGCOS DLOAD DCOMP
052902,000219: 13,2637 43244 BPL DAD
052903,000220: 13,2640 26644 NEGOUT
052904,000221: 13,2641 11760 DP1/2
052905,000222: 13,2642 00025 ARCTANXX STORE THETA
052906,000223: 13,2643 77616 RVQ
052907,000224:
052908,000225: 13,2644 52025 NEGOUT DSU GOTO
052909,000226: 13,2645 11760 DP1/2
052910,000227: 13,2646 26642 ARCTANXX
052911,000228: 13,2647 75345 ATAN=90 DLOAD SIGN
052912,000229: 13,2650 33412 LODP1/4
052913,000230: 13,2651 00023 SINTH
052914,000231: 13,2652 00025 STORE THETA
052915,000232: 13,2653 77616 RVQ
052916,000233:
052917,000234: 13,2654 04,3761 2DZERO = DPZERO
052918,000235:
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Page 1241 |
052920,000237: # ..... SETGAMMA SUBROUTINE .....
052921,000238: # SUBROUTINE TO SET GAMMA FOR THE LAT-LONG AND LALOTORV SUBROUTINES
052922,000239:
052923,000240: # GAMMA = B**2/A**2 FOR EARTH (B-1)
052924,000241: # GAMMA = 1 FOR MOON (B-1)
052925,000242:
052926,000243: # CALLING SEQUENCE
052927,000244: # L CALL
052928,000245: # L+1 SETGAMMA
052929,000246:
052930,000247: # INPUT
052931,000248: # LUNAFLAG=0 FOR EARTH, =1 FOR MOON
052932,000249:
052933,000250: # OUTPUT
052934,000251: # GAMMA IN GAMRP (B-1)
052935,000252:
052936,000253: 16,2000 SETLOC LATLONG1
052937,000254: 16,2000 BANK
052938,000255: 16,3766 COUNT* $$/LT-LG
052939,000256:
052940,000257: 16,3766 43145 SETGAMMA DLOAD BOFF # BRANCH FOR EARTH
052941,000258: 16,3767 26607 B2/A2 # EARTH GAMMA
052942,000259: 16,3770 01743 LUNAFLAG
052943,000260: 16,3771 35774 SETGMEX
052944,000261: 16,3772 77735 SLOAD
052945,000262: 16,3773 11760 1B1 # MOON GAMMA
052946,000263: 16,3774 00011 SETGMEX STORE GAMRP
052947,000264: 16,3775 77616 RVQ
052948,000265: 16,3776 GAMRP = 8D
052949,000266: 13,2000 SETLOC LATLONG
052950,000267: 13,2000 BANK
052951,000268:
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Page 1242 |
052953,000270: # ..... SETRE SUBROUTINE .....
052954,000271: # SUBROUTINE TO SET RE (EARTH OR MOON RADIUS)
052955,000272:
052956,000273: # RE = RM FOR MOON
052957,000274: # RE = RREF FOR FIXED EARTH RADIUS OR COMPUTED RF FOR FISCHER ELLIPSOID
052958,000275:
052959,000276: # CALLING SEQUENCE
052960,000277: # L CALL
052961,000278: # L+1 SETRE
052962,000279:
052963,000280: # SUBROUTINES USED
052964,000281: # GETERAD
052965,000282:
052966,000283: # INPUT
052967,000284: # ERADFLAG = 0 FOR FIXED RE, 1 FOR COMPUTED RE
052968,000285: # ALPHAV +4 = 1/2 SINL IF GETERAD IS CALLED
052969,000286: # LUNAFLAG = 0 FOR EARTH, =1 FOR MOON
052970,000287:
052971,000288: # OUTPUT
052972,000289: # ERADM = 504RM FOR MOON (METERS B-29)
052973,000290: # ERADM = ERAD OR COMPUTED RE FOR EARTH (METERS B-29)
052974,000291:
052975,000292: 13,2654 71220 SETRE STQ DLOAD
052976,000293: 13,2655 00051 SETREX
052977,000294: 13,2656 26701 504RM
052978,000295: 13,2657 71214 BON DLOAD # BRANCH FOR MOON
052979,000296: 13,2660 01703 LUNAFLAG
052980,000297: 13,2661 26671 TSTRLSRM
052981,000298: 13,2662 26613 ERAD
052982,000299: 13,2663 45014 BOFF CALL # ERADFLAG=0 FOR FIXED RE, 1 FOR COMPUTED
052983,000300: 13,2664 00742 ERADFLAG
052984,000301: 13,2665 26667 SETRXX
052985,000302: 13,2666 26570 GETERAD
052986,000303: 13,2667 36240 SETRXX STCALL ERADM # EXIT WITH RE OR RM METERS B-29
052987,000304: 13,2670 00051 SETREX
052988,000305: 13,2671 77214 TSTRLSRM BON VLOAD # ERADFLAG=0, SET R0=RLS
052989,000306: 13,2672 00702 ERADFLAG # =1 R0=RM
052990,000307: 13,2673 26667 SETRXX
052991,000308: 13,2674 02026 RLS
052992,000309: 13,2675 64446 ABVAL SR2R # SCALE FROM B-27 TO B-29
052993,000310: 13,2676 77650 GOTO
052994,000311: 13,2677 26667 SETRXX
052995,000312: 13,2700 0000051 SETREX = S2
052996,000313: 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