Source Code
|
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, 1971
Note that the date is the date of the printout, not the date of the program revision.
|
052905,000002: ## Copyright: Public domain.
052906,000003: ## Filename: LATITUDE_LONGITUDE_SUBROUTINES.agc
052907,000004: ## Purpose: Part of the source code for Artemis (i.e., Colossus 3),
052908,000005: ## build 072. This is for the Command Module's (CM)
052909,000006: ## Apollo Guidance Computer (AGC), for
052910,000007: ## Apollo 15-17.
052911,000008: ## Assembler: yaYUL
052912,000009: ## Contact: Sergio Navarro <sergionavarrog@gmail.com>
052913,000010: ## Website: www.ibiblio.org/apollo/index.html
052914,000011: ## Page Scans: www.ibiblio.org/apollo/ScansForConversion/Artemis072/
052915,000012: ## Mod history: 2009-09-03 SN Adapted from corresponding Comanche 055 file.
052916,000013: ## 2009-09-04 JL Fixed typos.
052917,000014: ## 2010-02-20 RSB Un-##'d this header.
052918,000015: ## 2010-04-13 JL Fixed a typo (' instead of #).
052919,000016: ## 2010-08-15 JL Fixed indentation.
052920,000017: ## 2017-02-05 RSB Proofed comment text by diff'ing vs Comanche 55
052921,000018: ## and corrected errors found.
052922,000019: ## 2017-03-15 RSB Comment-text fixes identified in 5-way
052923,000020: ## side-by-side diff of Luminary 69/99/116/131/210.
052924,000021:
|
|
Page 1236
|
052926,000023: # SUBROUTINE TO CONVERT RAD VECTOR AT GIVEN TIME TO LAT,LONG AND ALT
052927,000024:
052928,000025: # CALLING SEQUENCE
052929,000026:
052930,000027: # L-1 CALL
052931,000028: # L LAT-LONG
052932,000029:
052933,000030: # SUBROUTINES USED
052934,000031:
052935,000032: # R-TO-RP, ARCTAN, SETGAMMA, SETRE
052936,000033:
052937,000034: # ERASABLE INIT. REQ.
052938,000035:
052939,000036: # AXO, -AYO, AZO, TEPHEM (SET AT LAUNCH TIME)
052940,000037: # ALPHAV = POSITION VECTOR METERS B-29
052941,000038: # MPAC -- TIME (CSECS B-28)
052942,000039: # ERADFLAG =1, TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
052943,000040: # LUNAFLAG=0 FOR EARTH, 1 FOR MOON
052944,000041:
052945,000042: # OUTPUT
052946,000043:
052947,000044: # LATITUDE IN LAT (REVS. B-0)
052948,000045: # LONGITUDE IN LONG (REVS. B-0)
052949,000046: # ALTITUDE IN ALT METERS B-29
052950,000047:
052951,000048: 13,2000 SETLOC LATLONG
052952,000049: 13,2000 BANK
052953,000050:
052954,000051: 13,2453 COUNT* $$/LT-LG
052955,000052: 13,2453 E4,1551 EBANK= ALPHAV
052956,000053: 13,2453 40220 LAT-LONG STQ SETPD
052957,000054: 13,2454 02241 INCORPEX
052958,000055: 13,2455 00001 0D
052959,000056: 13,2456 24007 STOVL 6D # SAVE TIME IN 6-7D FOR R-TO-RP
052960,000057: 13,2457 02152 ALPHAV
052961,000058: 13,2460 51406 PUSH ABVAL # 0-5D= R FOR R-TO-RP
052962,000059: 13,2461 16301 STODL ALPHAM # ABS. VALUE OF R FOR ALT FORMULA BELOW
052963,000060: 13,2462 11762 ZEROVEC # SET MPAC=0 FOR EARTH, NON-ZERO FOR MOON
052964,000061: 13,2463 71414 BOFF COS # USE COS(0) TO GET NON-ZERO IN MPAC
052965,000062: 13,2464 01743 LUNAFLAG # 0=EARTH,1=MOON
052966,000063: 13,2465 26466 CALLRTRP
052967,000064: 13,2466 77624 CALLRTRP CALL
052968,000065: 13,2467 55370 R-TO-RP # RP VECTOR CONVERTED FROM R B-29
052969,000066: 13,2470 77656 UNIT # UNIT RP B-1
052970,000067: 13,2471 36152 STCALL ALPHAV # U2= 1/2 SINL FOR SETRE SUBR BELOW
052971,000068: 13,2472 35766 SETGAMMA # SET GAMMA=B2/A2 FOR EARTH, =1 FOR MOON
052972,000069: 13,2473 77624 CALL # SCALED B-1
052973,000070: 13,2474 26654 SETRE # CALC RE METERS B-29
052974,000071: 13,2475 63545 DLOAD DSQ
052975,000072: 13,2476 02152 ALPHAV
052976,000073: 13,2477 63525 PDDL DSQ
052977,000074: 13,2500 02154 ALPHAV +2
052978,000075: 13,2501 75415 DAD SQRT
052979,000076: 13,2502 76405 DMP SL1R
|
|
Page 1237
|
052981,000078: 13,2503 00011 GAMRP
052982,000079: 13,2504 14021 STODL COSTH # COS(LAT) B-1
052983,000080: 13,2505 02156 ALPHAV +4
052984,000081: 13,2506 34023 STCALL SINTH # SIN(LAT) B-1
052985,000082: 13,2507 26614 ARCTAN
052986,000083: 13,2510 14747 STODL LAT # LAT B0
052987,000084: 13,2511 02152 ALPHAV
052988,000085: 13,2512 14021 STODL COSTH # COS(LONG) B-1
052989,000086: 13,2513 02154 ALPHAV +2
052990,000087: 13,2514 34023 STCALL SINTH # SIN(LONG) B-1
052991,000088: 13,2515 26614 ARCTAN
052992,000089: 13,2516 14751 STODL LONG # LONG. REVS B-0 IN RANGE -1/2 TO 1/2
052993,000090: 13,2517 02301 ALPHAM
052994,000091: 13,2520 77625 DSU # ALT= R-RE METERS B-29
052995,000092: 13,2521 02240 ERADM
052996,000093: 13,2522 34753 STCALL ALT # EXIT WITH ALT METERS B-29
052997,000094: 13,2523 02241 INCORPEX
052998,000095:
|
|
Page 1238
|
053000,000097: # SUBROUTINE TO CONVERT LAT,LONG,ALT AT GIVEN TIME TO RADIUS VECTOR
053001,000098:
053002,000099: # CALLING SEQUENCE
053003,000100:
053004,000101: # L-1 CALL
053005,000102: # L LALOTORV
053006,000103:
053007,000104: # SUBROUTINES USED
053008,000105:
053009,000106: # SETGAMMA, SETRE, RP-TO-R
053010,000107:
053011,000108: # ERASABLE INIT. REQ.
053012,000109:
053013,000110: # AXO, AYO, AZO, TEPHEM SET AT LAUNCH TIME
053014,000111: # LAT -- LATITUDE (REVS B0)
053015,000112: # LONG -- LONGITUDE (REVS B0)
053016,000113: # ALT -- ALTITUDE (METERS) B-29
053017,000114: # MPAC -- TIME (CSECS B-28)
053018,000115: # ERADFLAG =1 TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
053019,000116: # LUNAFLAG=0 FOR EARTH, 1 FOR MOON
053020,000117:
053021,000118: # OUTPUT
053022,000119:
053023,000120: # R-VECTOR IN ALPHAV (METERS B-29)
053024,000121:
053025,000122: 13,2524 40220 LALOTORV STQ SETPD # LAT,LONG,ALT TO R VECTOR
053026,000123: 13,2525 02241 INCORPEX
053027,000124: 13,2526 00001 0D
053028,000125: 13,2527 34007 STCALL 6D # 6-7D = TIME FOR RP-TO-R
053029,000126: 13,2530 35766 SETGAMMA # GAMMA = B2/A2 FOR EARTH, 1 FOR MOON B-1
053030,000127: 13,2531 73545 DLOAD SIN # COS(LONG)COS(LAT) IN MPAC
053031,000128: 13,2532 00747 LAT # UNIT RP = SIN(LONG)COS(LAT) 2-3D
053032,000129: 13,2533 65275 DMPR PDDL # PD 2 GAMMA*SIN(LAT) 0-1D
053033,000130: 13,2534 00011 GAMRP
053034,000131: 13,2535 00747 LAT # 0-1D = GAMMA*SIN(LAT) B-2
053035,000132: 13,2536 65346 COS PDDL # PD4 2-3D = COS(LAT) B-1 TEMPORARILY
053036,000133: 13,2537 00751 LONG
053037,000134: 13,2540 57356 SIN DMPR # PD 2
053038,000135: 13,2541 71525 PDDL COS # PD 4 2-3D = SIN(LONG)COS(LAT) B-2
053039,000136: 13,2542 00747 LAT
053040,000137: 13,2543 71525 PDDL COS # PD 6 4-5D = COS(LAT) B-1 TEMPORARILY
053041,000138: 13,2544 00751 LONG
053042,000139: 13,2545 55475 DMPR VDEF # PD4 MPAC = COS(LONG)COS(LAT) B-2
053043,000140: 13,2546 41456 UNIT PUSH # 0-5D = UNIT RP FOR RP-TO-R SUBR.
053044,000141: 13,2547 36152 STCALL ALPHAV # ALPHAV +4= SINL FOR SETRE SUBR.
053045,000142: 13,2550 26654 SETRE # RE METERS B-29
053046,000143: 13,2551 43145 DLOAD BOFF # SET MPAC = 0 FOR EARTH, NON-ZERO FOR MOON
053047,000144: 13,2552 11762 ZEROVEC
053048,000145: 13,2553 01743 LUNAFLAG
053049,000146: 13,2554 26556 CALLRPRT
053050,000147: 13,2555 77746 COS # USE COS(0) TO GET NON-ZERO IN MPAC
053051,000148: 13,2556 77624 CALLRPRT CALL
053052,000149: 13,2557 55345 RP-TO-R # EXIT WITH UNIT R VECTOR IN MPAC
053053,000150: 13,2560 16152 STODL ALPHAV
053054,000151: 13,2561 02240 ERADM
|
|
Page 1239
|
053056,000153: 13,2562 74215 DAD VXSC # (RE + ALT)(UNIT R) METERS B-30
053057,000154: 13,2563 00753 ALT
053058,000155: 13,2564 02152 ALPHAV
053059,000156: 13,2565 77772 VSL1 # R METERS B-29
053060,000157: 13,2566 36152 STCALL ALPHAV # EXIT WITH R IN METERS B-29
053061,000158: 13,2567 02241 INCORPEX
053062,000159:
053063,000160: # SUBROUTINE TO COMPUTE EARTH RADIUS
053064,000161:
053065,000162: # INPUT
053066,000163:
053067,000164: # 1/2 SIN LAT IN ALPHAV +4
053068,000165:
053069,000166: # OUTPUT
053070,000167:
053071,000168: # EARTH RADIUS IN ERADM AND MPAC (METERS B-29)
053072,000169:
053073,000170: 13,2570 63545 GETERAD DLOAD DSQ
053074,000171: 13,2571 02156 ALPHAV +4 # SIN**2(L)
053075,000172: 13,2572 44352 SL1 BDSU
053076,000173: 13,2573 11760 DP1/2 # COS**2(L)
053077,000174: 13,2574 44275 DMPR BDSU
053078,000175: 13,2575 26611 EE
053079,000176: 13,2576 11760 DP1/2
053080,000177: 13,2577 75465 BDDV SQRT
053081,000178: 13,2600 26605 B2XSC
053082,000179: 13,2601 77622 SR4R
053083,000180: 13,2602 02240 STORE ERADM
053084,000181: 13,2603 77616 RVQ
053085,000182:
053086,000183: # THE FOLLOWING CONSTANTS WERE COMPUTED WITH A=6378166, B=6356784 METERS
053087,000184: # B2XSC = B**2 SCALED B-51
053088,000185: # B2/A2 = B**2/A**2 SCALED B-1
053089,000186: # EE = (1-B**2/A**2) SCALED B-0
053090,000187:
053091,000188: 13,2604 00446 00305 B2XSC 2DEC .0179450689 # B**2 SCALED B-51
053092,000189: 13,2606 04,3757 DP1/2 = XUNIT
053093,000190: 13,2606 17711 05254 B2/A2 2DEC .9933064884 B-1 # GAMMA= B**2/A**2 B-1
053094,000191: 13,2610 00155 25250 EE 2DEC 6.6935116 E-3 # (1-B**2/A**2) B-0
053095,000192: 13,2612 00302 17755 ERAD 2DEC 6373338 B-29 # PAD RADIUS
053096,000193:
|
|
Page 1240
|
053098,000195: # ARCTAN SUBROUTINE
053099,000196:
053100,000197: # CALLING SEQUENCE
053101,000198:
053102,000199: # SIN THETA IN SINTH B-1
053103,000200: # COS THETA IN COSTH B-1
053104,000201: # CALL ARCTAN
053105,000202:
053106,000203: # OUTPUT
053107,000204: # ARCTAN THETA IN MPAC AND THETA B-0 IN RANGE -1/2 TO +1/2
053108,000205:
053109,000206: 13,2614 77600 ARCTAN BOV
053110,000207: 13,2615 26616 CLROVFLW
053111,000208: 13,2616 63545 CLROVFLW DLOAD DSQ
053112,000209: 13,2617 00023 SINTH
053113,000210: 13,2620 63525 PDDL DSQ
053114,000211: 13,2621 00021 COSTH
053115,000212: 13,2622 77615 DAD
053116,000213: 13,2623 75454 BZE SQRT
053117,000214: 13,2624 26642 ARCTANXX # ATAN=0/0 SET THETA=0
053118,000215: 13,2625 40065 BDDV BOV
053119,000216: 13,2626 00023 SINTH
053120,000217: 13,2627 26647 ATAN=90
053121,000218: 13,2630 67542 SR1 ASIN
053122,000219: 13,2631 00025 STORE THETA
053123,000220: 13,2632 50125 PDDL BMN
053124,000221: 13,2633 00021 COSTH
053125,000222: 13,2634 26636 NEGCOS
053126,000223: 13,2635 43545 DLOAD RVQ
053127,000224: 13,2636 57545 NEGCOS DLOAD DCOMP
053128,000225: 13,2637 43244 BPL DAD
053129,000226: 13,2640 26644 NEGOUT
053130,000227: 13,2641 11760 DP1/2
053131,000228: 13,2642 00025 ARCTANXX STORE THETA
053132,000229: 13,2643 77616 RVQ
053133,000230:
053134,000231: 13,2644 52025 NEGOUT DSU GOTO
053135,000232: 13,2645 11760 DP1/2
053136,000233: 13,2646 26642 ARCTANXX
053137,000234: 13,2647 75345 ATAN=90 DLOAD SIGN
053138,000235: 13,2650 33412 LODP1/4
053139,000236: 13,2651 00023 SINTH
053140,000237: 13,2652 00025 STORE THETA
053141,000238: 13,2653 77616 RVQ
053142,000239:
053143,000240: 13,2654 04,3761 2DZERO = DPZERO
053144,000241:
|
|
Page 1241
|
053146,000243: # ..... SETGAMMA SUBROUTINE .....
053147,000244: # SUBROUTINE TO SET GAMMA FOR THE LAT-LONG AND LALOTORV SUBROUTINES
053148,000245:
053149,000246: # GAMMA = B**2/A**2 FOR EARTH (B-1)
053150,000247: # GAMMA = 1 FOR MOON (B-1)
053151,000248:
053152,000249: # CALLING SEQUENCE
053153,000250: # L CALL
053154,000251: # L+1 SETGAMMA
053155,000252:
053156,000253: # INPUT
053157,000254: # LUNAFLAG=0 FOR EARTH, =1 FOR MOON
053158,000255:
053159,000256: # OUTPUT
053160,000257: # GAMMA IN GAMRP (B-1)
053161,000258:
053162,000259: 16,2000 SETLOC LATLONG1
053163,000260: 16,2000 BANK
053164,000261: 16,3766 COUNT* $$/LT-LG
053165,000262:
053166,000263: 16,3766 43145 SETGAMMA DLOAD BOFF # BRANCH FOR EARTH
053167,000264: 16,3767 26607 B2/A2 # EARTH GAMMA
053168,000265: 16,3770 01743 LUNAFLAG
053169,000266: 16,3771 35774 SETGMEX
053170,000267: 16,3772 77735 SLOAD
053171,000268: 16,3773 11760 1B1 # MOON GAMMA
053172,000269: 16,3774 00011 SETGMEX STORE GAMRP
053173,000270: 16,3775 77616 RVQ
053174,000271: 16,3776 GAMRP = 8D
053175,000272: 13,2000 SETLOC LATLONG
053176,000273: 13,2000 BANK
053177,000274:
|
|
Page 1242
|
053179,000276: # ..... SETRE SUBROUTINE .....
053180,000277: # SUBROUTINE TO SET RE (EARTH OR MOON RADIUS)
053181,000278:
053182,000279: # RE = RM FOR MOON
053183,000280: # RE = RREF FOR FIXED EARTH RADIUS OR COMPUTED RF FOR FISCHER ELLIPSOID
053184,000281:
053185,000282: # CALLING SEQUENCE
053186,000283: # L CALL
053187,000284: # L+1 SETRE
053188,000285:
053189,000286: # SUBROUTINES USED
053190,000287: # GETERAD
053191,000288:
053192,000289: # INPUT
053193,000290: # ERADFLAG = 0 FOR FIXED RE, 1 FOR COMPUTED RE
053194,000291: # ALPHAV +4 = 1/2 SINL IF GETERAD IS CALLED
053195,000292: # LUNAFLAG = 0 FOR EARTH, =1 FOR MOON
053196,000293:
053197,000294: # OUTPUT
053198,000295: # ERADM = 504RM FOR MOON (METERS B-29)
053199,000296: # ERADM = ERAD OR COMPUTED RF FOR EARTH (METERS B-29)
053200,000297:
053201,000298: 13,2654 71220 SETRE STQ DLOAD
053202,000299: 13,2655 00051 SETREX
053203,000300: 13,2656 26701 504RM
053204,000301: 13,2657 71214 BON DLOAD # BRANCH FOR MOON
053205,000302: 13,2660 01703 LUNAFLAG
053206,000303: 13,2661 26671 TSTRLSRM
053207,000304: 13,2662 26613 ERAD
053208,000305: 13,2663 45014 BOFF CALL # ERADFLAG=0 FOR FIXED RE, 1 FOR COMPUTED
053209,000306: 13,2664 00742 ERADFLAG
053210,000307: 13,2665 26667 SETRXX
053211,000308: 13,2666 26570 GETERAD
053212,000309: 13,2667 36240 SETRXX STCALL ERADM # EXIT WITH RE OR RM METERS B-29
053213,000310: 13,2670 00051 SETREX
053214,000311: 13,2671 77214 TSTRLSRM BON VLOAD # ERADFLAG=0, SET R0=RLS
053215,000312: 13,2672 00702 ERADFLAG # =1 R0=RM
053216,000313: 13,2673 26667 SETRXX
053217,000314: 13,2674 02026 RLS
053218,000315: 13,2675 64446 ABVAL SR2R # SCALE FROM B-27 TO B-29
053219,000316: 13,2676 77650 GOTO
053220,000317: 13,2677 26667 SETRXX
053221,000318: 13,2700 0000051 SETREX = S2
053222,000319: 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