Source Code
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These source-code files were transcribed from scans made from Don Eyles's personal
copy of Luminary 069. They were scanned at archive.org's Boston
facility, and the scanning was sponsored by Onno Hommes. The code was transcribed
from these scans by a team of volunteers who are referenced in the program
comments. Comments from the original source code are prefixed with a single '#' symbol,
whereas comments added later are prefixed by "##" or "###". In some cases, where
similar code blocks exist in previously-transcribed AGC programs (primarily
Luminary 99, from Apollo 11) those code blocks were used as a starting point and
then corrected to agree with the Luminary 69 scans. The full scans are available
at the Virtual AGC
project's collection at archive.org, while more-convenient reduced-size (but reduced-quality)
images are available at
the main Virtual AGC website. Report any errors noted by creating an
issue report at the Virtual AGC
project's GitHub repository. Notations on the program listing read, in part:GAP: ASSEMBLE REVISION 069 OF AGC PROGRAM LUMINARY BY NASA 2021112-011 19:02 NOV. 25,1968Note that the date is the date of the printout, not the date of the program revision. |
048691,000002: ## Copyright: Public domain.
048692,000003: ## Filename: LATITUDE_LONGITUDE_SUBROUTINES.agc
048693,000004: ## Purpose: The main source file for Luminary revision 069.
048694,000005: ## It is part of the source code for the original release
048695,000006: ## of the flight software for the Lunar Module's (LM) Apollo
048696,000007: ## Guidance Computer (AGC) for Apollo 10. The actual flown
048697,000008: ## version was Luminary 69 revision 2, which included a
048698,000009: ## newer lunar gravity model and only affected module 2.
048699,000010: ## This file is intended to be a faithful transcription, except
048700,000011: ## that the code format has been changed to conform to the
048701,000012: ## requirements of the yaYUL assembler rather than the
048702,000013: ## original YUL assembler.
048703,000014: ## Reference: pp. 1128-1134
048704,000015: ## Assembler: yaYUL
048705,000016: ## Contact: Ron Burkey <info@sandroid.org>.
048706,000017: ## Website: www.ibiblio.org/apollo/index.html
048707,000018: ## Mod history: 2016-12-13 MAS Created from Luminary 99.
048708,000019: ## 2016-12-18 MAS Updated from comment-proofed Luminary 99 version.
048709,000020: ## 2017-01-28 RSB Proofed comment text using octopus/prooferComments
048710,000021: ## and fixed errors found.
048711,000022: ## 2017-03-15 RSB Comment-text fixes identified in 5-way
048712,000023: ## side-by-side diff of Luminary 69/99/116/131/210.
048713,000024:
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Page 1128 |
048715,000026: # SUBROUTINE TO CONVERT RAD VECTOR AT GIVEN TIME TO LAT,LONG AND ALT
048716,000027:
048717,000028: # CALLING SEQUENCE
048718,000029: # L-1 CALL
048719,000030: # L LAT-LONG
048720,000031:
048721,000032: # SUBROUTINES USED
048722,000033: # R-TO-RP,ARCTAN,SETGAMMA,SETRE
048723,000034:
048724,000035: # ERASABLE INIT. REQ.
048725,000036: # AXO,-AYO,AZO,TEPHEM (SET AT LAUNCH TIME)
048726,000037: # ALPHAV = POSITION VECTOR METERS B-29
048727,000038: # MPAC-- TIME (CSECS B-28)
048728,000039: # ERADFLAG =1, TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
048729,000040: # LUNAFLAG=0 FOR EARTH, 1 FOR MOON
048730,000041:
048731,000042: # OUTPUT
048732,000043: # LATITUDE IN LAT (REVS. B-0)
048733,000044: # LONGITUDE IN LONG (REVS. B-0)
048734,000045: # ALTITUDE IN ALT METERS B-29
048735,000046:
048736,000047: 30,3746 BANK 30
048737,000048: 13,2000 SETLOC LATLONG
048738,000049: 13,2000 BANK
048739,000050:
048740,000051: 13,2351 COUNT* $$/LT-LG
048741,000052: 13,2351 E4,1431 EBANK= ALPHAV
048742,000053: 13,2351 40220 LAT-LONG STQ SETPD
048743,000054: 13,2352 03672 INCORPEX
048744,000055: 13,2353 00001 0D
048745,000056: 13,2354 24007 STOVL 6D # SAVE TIME IN 6-7D FOR R-TO-RP
048746,000057: 13,2355 02032 ALPHAV
048747,000058: 13,2356 51406 PUSH ABVAL # 0-5D= R FOR R-TO-RP
048748,000059: 13,2357 16070 STODL ALPHAM # ABS. VALUE OF R FOR ALT FORMULA BELOW
048749,000060: 13,2360 22275 ZEROVEC # SET MPAC=0 FOR EARTH, NON-ZERO FOR MOON
048750,000061: 13,2361 71414 BOFF COS # USE COS(0) TO GET NON-ZERO IN MPAC
048751,000062: 13,2362 01743 LUNAFLAG # 0=EARTH, 1=MOON
048752,000063: 13,2363 26364 CALLRTRP
048753,000064: 13,2364 77624 CALLRTRP CALL
048754,000065: 13,2365 51531 R-TO-RP # RP VECTOR CONVERTED FROM R B-29
048755,000066: 13,2366 77656 UNIT # UNIT RP B-1
048756,000067: 13,2367 36032 STCALL ALPHAV # U2= 1/2 SINL FOR SETRE SUBR BELOW
048757,000068: 13,2370 26550 SETGAMMA # SET GAMMA=B2/A2 FOR EARTH,=1 FOR MOON
048758,000069: 13,2371 77624 CALL # SCALED B-1
048759,000070: 13,2372 26560 SETRE # CALC RE METERS B-29
048760,000071: 13,2373 63545 DLOAD DSQ
048761,000072: 13,2374 02032 ALPHAV
048762,000073: 13,2375 63525 PDDL DSQ
048763,000074: 13,2376 02034 ALPHAV +2
048764,000075: 13,2377 75415 DAD SQRT
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Page 1129 |
048766,000077: 13,2400 76405 DMP SL1R
048767,000078: 13,2401 00011 GAMRP
048768,000079: 13,2402 14021 STODL COSTH # COS(LAT) B-1
048769,000080: 13,2403 02036 ALPHAV +4
048770,000081: 13,2404 34023 STCALL SINTH # SIN(LAT) B-1
048771,000082: 13,2405 26510 ARCTAN
048772,000083: 13,2406 15121 STODL LAT # LAT B0
048773,000084: 13,2407 02032 ALPHAV
048774,000085: 13,2410 14021 STODL COSTH # COS(LONG) B-1
048775,000086: 13,2411 02034 ALPHAV +2
048776,000087: 13,2412 34023 STCALL SINTH # SIN(LONG) B-1
048777,000088: 13,2413 26510 ARCTAN
048778,000089: 13,2414 15123 STODL LONG # LONG. REVS B-0 IN RANGE -1/2 TO 1/2
048779,000090: 13,2415 02070 ALPHAM
048780,000091: 13,2416 77625 DSU # ALT= R-RE METERS B-29
048781,000092: 13,2417 03671 ERADM
048782,000093: 13,2420 35125 STCALL ALT # EXIT WITH ALT METERS B-29
048783,000094: 13,2421 03672 INCORPEX
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Page 1130 |
048785,000096: # SUBROUTINE TO CONVERT LAT,LONG,ALT AT GIVEN TIME TO RADIUS VECTOR
048786,000097:
048787,000098: # CALLING SEQUENCE
048788,000099: # L-1 CALL
048789,000100: # L LALOTORV
048790,000101:
048791,000102: # SUBROUTINES USED
048792,000103: # SETGAMMA,SETRE,RP-TO-R
048793,000104:
048794,000105: # ERASABLE INIT. REQ.
048795,000106: # AXO,AYO,AZO,TEPHEM SET AT LAUNCH TIME
048796,000107: # LAT-- LATITUDE (REVS B0)
048797,000108: # LONG-- LONGITUDE (REVS B0)
048798,000109: # ALT--ALTITUDE (METERS) B-29
048799,000110: # MPAC-- TIME (CSECS B-28)
048800,000111: # ERADFLAG =1 TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
048801,000112: # LUNAFLAG=0 FOR EARTH, 1 FOR MOON
048802,000113:
048803,000114: # OUTPUT
048804,000115: # R-VECTOR IN ALPHAV (METERS B-29)
048805,000116:
048806,000117: 13,2422 40220 LALOTORV STQ SETPD # LAT,LONG,ALT TO R VECTOR
048807,000118: 13,2423 03672 INCORPEX
048808,000119: 13,2424 00001 0D
048809,000120: 13,2425 34007 STCALL 6D # 6-7D= TIME FOR RP-TO-R
048810,000121: 13,2426 26550 SETGAMMA # GAMMA=B2/A2 FOR EARTH,1 FOR MOON B-1
048811,000122: 13,2427 73545 DLOAD SIN # COS(LONG)COS(LAT) IN MPAC
048812,000123: 13,2430 01121 LAT # UNIT RP= SIN(LONG)COS(LAT) 2-3D
048813,000124: 13,2431 65275 DMPR PDDL # PD 2 GAMMA*SIN(LAT) 0-1D
048814,000125: 13,2432 00011 GAMRP
048815,000126: 13,2433 01121 LAT # 0-1D= GAMMA*SIN(LAT) B-2
048816,000127: 13,2434 65346 COS PDDL # PD 4 2-3D=COS(LAT) B-1 TEMPORARILY
048817,000128: 13,2435 01123 LONG
048818,000129: 13,2436 57356 SIN DMPR # PD 2
048819,000130: 13,2437 71525 PDDL COS # PD 4 2-3D=SIN(LONG)COS(LAT) B-2
048820,000131: 13,2440 01121 LAT
048821,000132: 13,2441 71525 PDDL COS # PD 6 4-5D=COS(LAT) B-1 TEMPORARILY
048822,000133: 13,2442 01123 LONG
048823,000134: 13,2443 55475 DMPR VDEF # PD 4 MPAC= COS(LONG)COS(LAT) B-2
048824,000135: 13,2444 41456 UNIT PUSH # 0-5D= UNIT RP FOR RP-TO-R SUBR.
048825,000136: 13,2445 36032 STCALL ALPHAV # ALPHAV +4= SINL FOR SETRE SUBR.
048826,000137: 13,2446 26560 SETRE # RE METERS B-29
048827,000138: 13,2447 43145 DLOAD BOFF # SET MPAC=0 FOR EARTH, NON-ZERO FOR MOON
048828,000139: 13,2450 22275 ZEROVEC
048829,000140: 13,2451 01743 LUNAFLAG
048830,000141: 13,2452 26454 CALLRPRT
048831,000142: 13,2453 77746 COS # USE COS(0) TO GET NON-ZERO IN MPAC
048832,000143: 13,2454 77624 CALLRPRT CALL
048833,000144: 13,2455 51504 RP-TO-R # EXIT WITH UNIT R VECTOR IN MPAC
048834,000145: 13,2456 16032 STODL ALPHAV
048835,000146: 13,2457 03671 ERADM
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Page 1131 |
048837,000148: 13,2460 74215 DAD VXSC # (RE + ALT)(UNIT R) METERS B-30
048838,000149: 13,2461 01125 ALT
048839,000150: 13,2462 02032 ALPHAV
048840,000151: 13,2463 77772 VSL1 # R METERS B-29
048841,000152: 13,2464 36032 STCALL ALPHAV # EXIT WITH R IN METERS B-29
048842,000153: 13,2465 03672 INCORPEX
048843,000154:
048844,000155: # SUBROUTINE TO COMPUTE EARTH RADIUS
048845,000156:
048846,000157: # INPUT
048847,000158: # 1/2 SIN LAT IN ALPHAV +4
048848,000159:
048849,000160: # OUTPUT
048850,000161: # EARTH RADIUS IN ERADM AND MPAC (METERS B-29)
048851,000162:
048852,000163: 13,2466 63545 GETERAD DLOAD DSQ
048853,000164: 13,2467 02036 ALPHAV +4 # SIN**2(L)
048854,000165: 13,2470 44352 SL1 BDSU
048855,000166: 13,2471 22273 DP1/2 # COS**2(L)
048856,000167: 13,2472 44275 DMPR BDSU
048857,000168: 13,2473 26507 EE
048858,000169: 13,2474 22273 DP1/2
048859,000170: 13,2475 75465 BDDV SQRT
048860,000171: 13,2476 26503 B2XSC
048861,000172: 13,2477 77622 SR4R
048862,000173: 13,2500 03671 STORE ERADM
048863,000174: 13,2501 77616 RVQ
048864,000175:
048865,000176: # THE FOLLOWING CONSTANTS WERE COMPUTED WITH A=6378166, B=6356784 METERS
048866,000177: # B2XSC= B**2 SCALED B-51
048867,000178: # B2/A2= B**2/A**2 SCALED B-1
048868,000179: # EE=(1-B**2/A**2) SCALED B-0
048869,000180:
048870,000181: 13,2502 00446 00305 B2XSC 2DEC .0179450689 # B**2 SCALED B-51
048871,000182: 13,2504 11,2272 DP1/2 = XUNIT
048872,000183: 13,2504 17711 05254 B2/A2 2DEC .9933064884 B-1 # GAMMA= B**2/A**2 B-1
048873,000184: 13,2506 00155 25250 EE 2DEC 6.6935116 E-3 # (1-B**2/A**2) B-0
048874,000185:
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Page 1132 |
048876,000187: # ARCTAN SUBROUTINE
048877,000188:
048878,000189: # CALLING SEQUENCE
048879,000190: # SIN THETA IN SINTH B-1
048880,000191: # COS THETA IN COSTH B-1
048881,000192: # CALL ARCTAN
048882,000193:
048883,000194: # OUTPUT
048884,000195: # ARCTAN THETA IN MPAC AND THETA B-0 IN RANGE -1/2 TO +1/2
048885,000196:
048886,000197: 13,2510 77600 ARCTAN BOV
048887,000198: 13,2511 26512 CLROVFLW
048888,000199: 13,2512 63545 CLROVFLW DLOAD DSQ
048889,000200: 13,2513 00023 SINTH
048890,000201: 13,2514 63525 PDDL DSQ
048891,000202: 13,2515 00021 COSTH
048892,000203: 13,2516 77615 DAD
048893,000204: 13,2517 75454 BZE SQRT
048894,000205: 13,2520 26536 ARCTANXX # ATAN=0/0 SET THETA=0
048895,000206: 13,2521 40065 BDDV BOV
048896,000207: 13,2522 00023 SINTH
048897,000208: 13,2523 26543 ATAN=90
048898,000209: 13,2524 67542 SR1 ASIN
048899,000210: 13,2525 00025 STORE THETA
048900,000211: 13,2526 50125 PDDL BMN
048901,000212: 13,2527 00021 COSTH
048902,000213: 13,2530 26532 NEGCOS
048903,000214: 13,2531 43545 DLOAD RVQ
048904,000215: 13,2532 57545 NEGCOS DLOAD DCOMP
048905,000216: 13,2533 43244 BPL DAD
048906,000217: 13,2534 26540 NEGOUT
048907,000218: 13,2535 22273 DP1/2
048908,000219: 13,2536 00025 ARCTANXX STORE THETA
048909,000220: 13,2537 77616 RVQ
048910,000221:
048911,000222: 13,2540 52025 NEGOUT DSU GOTO
048912,000223: 13,2541 22273 DP1/2
048913,000224: 13,2542 26536 ARCTANXX
048914,000225: 13,2543 75345 ATAN=90 DLOAD SIGN
048915,000226: 13,2544 10760 LODP1/4
048916,000227: 13,2545 00023 SINTH
048917,000228: 13,2546 00025 STORE THETA
048918,000229: 13,2547 77616 RVQ
048919,000230:
048920,000231: 13,2550 11,2274 2DZERO = DPZERO
048921,000232:
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Page 1133 |
048923,000234: # ..... SETGAMMA SUBROUTINE .....
048924,000235: # SUBROUTINE TO SET GAMMA FOR THE LAT-LONG AND LALOTORV SUBROUTINES
048925,000236:
048926,000237: # GAMMA = B**2/A**2 FOR EARTH (B-1)
048927,000238: # GAMMA = 1 FOR MOON (B-1)
048928,000239:
048929,000240: # CALLING SEQUENCE
048930,000241: # L CALL
048931,000242: # L+1 SETGAMMA
048932,000243:
048933,000244: # INPUT
048934,000245: # LUNAFLAG=0 FOR EARTH,=1 FOR MOON
048935,000246:
048936,000247: # OUTPUT
048937,000248: # GAMMA IN GAMRP (B-1)
048938,000249:
048939,000250: 13,2550 43145 SETGAMMA DLOAD BOFF # BRANCH FOR EARTH
048940,000251: 13,2551 26505 B2/A2 # EARTH GAMMA
048941,000252: 13,2552 01743 LUNAFLAG
048942,000253: 13,2553 26556 SETGMEX
048943,000254: 13,2554 77735 SLOAD
048944,000255: 13,2555 22273 1B1 # MOON GAMMA
048945,000256: 13,2556 00011 SETGMEX STORE GAMRP
048946,000257: 13,2557 77616 RVQ
048947,000258: 13,2560 GAMRP = 8D
048948,000259:
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Page 1134 |
048950,000261: # ..... SETRE SUBROUTINE .....
048951,000262: # SUBROUTINE TO SET RE (EARTH OR MOON RADIUS)
048952,000263:
048953,000264: # RE= RM FOR MOON
048954,000265: # RE= RREF FOR FIXED EARTH RADIUS OR COMPUTED RF FOR FISCHER ELLIPSOID
048955,000266:
048956,000267: # CALLING SEQUENCE
048957,000268: # L CALL
048958,000269: # L+1 SETRE
048959,000270:
048960,000271: # SUBROUTINES USED
048961,000272: # GETERAD
048962,000273:
048963,000274: # INPUT
048964,000275: # ERADFLAG=0 FOR FIXED RE, 1 FOR COMPUTED RE
048965,000276: # ALPHAV +4= 1/2 SINL IF GETERAD IS CALLED
048966,000277: # LUNAFLAG=0 FOR EARTH,=1 FOR MOON
048967,000278:
048968,000279: # OUTPUT
048969,000280: # ERADM= 504RM FOR MOON (METERS B-29)
048970,000281: # ERADM= ERAD OR COMPUTED RF FOR EARTH (METERS B-29)
048971,000282:
048972,000283: 13,2560 71220 SETRE STQ DLOAD
048973,000284: 13,2561 00051 SETREX
048974,000285: 13,2562 10003 504RM
048975,000286: 13,2563 71214 BON DLOAD # BRANCH FOR MOON
048976,000287: 13,2564 01703 LUNAFLAG
048977,000288: 13,2565 26575 TSTRLSRM
048978,000289: 13,2566 10001 ERAD
048979,000290: 13,2567 45014 BOFF CALL # ERADFLAG=0 FOR FIXED RE, 1 FOR COMPUTED
048980,000291: 13,2570 00742 ERADFLAG
048981,000292: 13,2571 26573 SETRXX
048982,000293: 13,2572 26466 GETERAD
048983,000294: 13,2573 37671 SETRXX STCALL ERADM # EXIT WITH RE OR RM METERS B-29
048984,000295: 13,2574 00051 SETREX
048985,000296: 13,2575 77214 TSTRLSRM BON VLOAD # ERADFLAG=0, SET R0=RLS
048986,000297: 13,2576 00702 ERADFLAG # =1 R0=RM
048987,000298: 13,2577 26573 SETRXX
048988,000299: 13,2600 02023 RLS
048989,000300: 13,2601 64446 ABVAL SR2R # SCALE FROM B-27 TO B-29
048990,000301: 13,2602 77650 GOTO
048991,000302: 13,2603 26573 SETRXX
048992,000303: 13,2604 0000051 SETREX = S2
048993,000304:
048994,000305:
End of include-file LATITUDE_LONGITUDE_SUBROUTINES.agc. Parent file is MAIN.agc