Source Code
|
These source code files are a reconstruction of Sundance, the Apollo 9 LM (Lunar Module) AGC
(Apollo Guidance Computer) flight software, created from binary dumps of original core rope
program modules, as follows:
Since only binary dumps (rather than listings) of Sundance are available as source material, all comments and labels are approximate. They have been taken from other AGC programs where possible, or, in some places, written from scratch to match what we believe would have been in the original listing. |
043476,000002: ## Copyright: Public domain.
043477,000003: ## Filename: LATITUDE_LONGITUDE_SUBROUTINES.agc
043478,000004: ## Purpose: A section of a reconstructed, mixed version of Sundance
043479,000005: ## It is part of the reconstructed source code for the Lunar
043480,000006: ## Module's (LM) Apollo Guidance Computer (AGC) for Apollo 9.
043481,000007: ## No original listings of this program are available;
043482,000008: ## instead, this file was created via disassembly of dumps
043483,000009: ## of various revisions of Sundance core rope modules.
043484,000010: ## Assembler: yaYUL
043485,000011: ## Contact: Ron Burkey <info@sandroid.org>.
043486,000012: ## Website: www.ibiblio.org/apollo/index.html
043487,000013: ## Mod history: 2020-06-17 MAS Created from Luminary 69.
043488,000014:
043489,000015: ## Sundance 302
043490,000016:
043491,000017: # SUBROUTINE TO CONVERT RAD VECTOR AT GIVEN TIME TO LAT,LONG AND ALT
043492,000018:
043493,000019: # CALLING SEQUENCE
043494,000020: # L-1 CALL
043495,000021: # L LAT-LONG
043496,000022:
043497,000023: # SUBROUTINES USED
043498,000024: # R-TO-RP,ARCTAN,SETGAMMA,SETRE
043499,000025:
043500,000026: # ERASABLE INIT. REQ.
043501,000027: # AXO,-AYO,AZO,TEPHEM (SET AT LAUNCH TIME)
043502,000028: # ALPHAV = POSITION VECTOR METERS B-29
043503,000029: # MPAC-- TIME (CSECS B-28)
043504,000030: # ERADFLAG =1, TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
043505,000031: # LUNAFLAG=0 FOR EARTH, 1 FOR MOON
043506,000032:
043507,000033: # OUTPUT
043508,000034: # LATITUDE IN LAT (REVS. B-0)
043509,000035: # LONGITUDE IN LONG (REVS. B-0)
043510,000036: # ALTITUDE IN ALT METERS B-29
043511,000037:
043512,000038: 30,3645 BANK 30
043513,000039: 13,2000 SETLOC LATLONG
043514,000040: 13,2000 BANK
043515,000041:
043516,000042: 13,2323 COUNT* $$/LT-LG
043517,000043: 13,2323 E4,1433 EBANK= ALPHAV
043518,000044: 13,2323 40220 LAT-LONG STQ SETPD
043519,000045: 13,2324 03661 INCORPEX
043520,000046: 13,2325 00001 0D
043521,000047: 13,2326 24007 STOVL 6D # SAVE TIME IN 6-7D FOR R-TO-RP
043522,000048: 13,2327 02034 ALPHAV
043523,000049: 13,2330 51406 PUSH ABVAL # 0-5D= R FOR R-TO-RP
043524,000050: 13,2331 16072 STODL ALPHAM # ABS. VALUE OF R FOR ALT FORMULA BELOW
043525,000051: 13,2332 22276 ZEROVEC # SET MPAC=0 FOR EARTH, NON-ZERO FOR MOON
043526,000052: 13,2333 71414 BOFF COS # USE COS(0) TO GET NON-ZERO IN MPAC
043527,000053: 13,2334 01743 LUNAFLAG # 0=EARTH, 1=MOON
043528,000054: 13,2335 26336 CALLRTRP
043529,000055: 13,2336 77624 CALLRTRP CALL
043530,000056: 13,2337 51245 R-TO-RP # RP VECTOR CONVERTED FROM R B-29
043531,000057: 13,2340 77656 UNIT # UNIT RP B-1
043532,000058: 13,2341 36034 STCALL ALPHAV # U2= 1/2 SINL FOR SETRE SUBR BELOW
043533,000059: 13,2342 26524 SETGAMMA # SET GAMMA=B2/A2 FOR EARTH,=1 FOR MOON
043534,000060: 13,2343 77624 CALL # SCALED B-1
043535,000061: 13,2344 26534 SETRE # CALC RE METERS B-29
043536,000062: 13,2345 63545 DLOAD DSQ
043537,000063: 13,2346 02034 ALPHAV
043538,000064: 13,2347 63525 PDDL DSQ
043539,000065: 13,2350 02036 ALPHAV +2
043540,000066: 13,2351 75415 DAD SQRT
043541,000067: 13,2352 76405 DMP SL1R
043542,000068: 13,2353 00011 GAMRP
043543,000069: 13,2354 14021 STODL COSTH # COS(LAT) B-1
043544,000070: 13,2355 02040 ALPHAV +4
043545,000071: 13,2356 34023 STCALL SINTH # SIN(LAT) B-1
043546,000072: 13,2357 26464 ARCTAN
043547,000073: 13,2360 15124 STODL LAT # LAT B0
043548,000074: 13,2361 02034 ALPHAV
043549,000075: 13,2362 14021 STODL COSTH # COS(LONG) B-1
043550,000076: 13,2363 02036 ALPHAV +2
043551,000077: 13,2364 34023 STCALL SINTH # SIN(LONG) B-1
043552,000078: 13,2365 26464 ARCTAN
043553,000079: 13,2366 15126 STODL LONG # LONG. REVS B-0 IN RANGE -1/2 TO 1/2
043554,000080: 13,2367 02072 ALPHAM
043555,000081: 13,2370 77625 DSU # ALT= R-RE METERS B-29
043556,000082: 13,2371 03660 ERADM
043557,000083: 13,2372 35130 STCALL ALT # EXIT WITH ALT METERS B-29
043558,000084: 13,2373 03661 INCORPEX
043559,000085: # SUBROUTINE TO CONVERT LAT,LONG,ALT AT GIVEN TIME TO RADIUS VECTOR
043560,000086:
043561,000087: # CALLING SEQUENCE
043562,000088: # L-1 CALL
043563,000089: # L LALOTORV
043564,000090:
043565,000091: # SUBROUTINES USED
043566,000092: # SETGAMMA,SETRE,RP-TO-R
043567,000093:
043568,000094: # ERASABLE INIT. REQ.
043569,000095: # AXO,AYO,AZO,TEPHEM SET AT LAUNCH TIME
043570,000096: # LAT-- LATITUDE (REVS B0)
043571,000097: # LONG-- LONGITUDE (REVS B0)
043572,000098: # ALT--ALTITUDE (METERS) B-29
043573,000099: # MPAC-- TIME (CSECS B-28)
043574,000100: # ERADFLAG =1 TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
043575,000101: # LUNAFLAG=0 FOR EARTH, 1 FOR MOON
043576,000102:
043577,000103: # OUTPUT
043578,000104: # R-VECTOR IN ALPHAV (METERS B-29)
043579,000105:
043580,000106: 13,2374 40220 LALOTORV STQ SETPD # LAT,LONG,ALT TO R VECTOR
043581,000107: 13,2375 03661 INCORPEX
043582,000108: 13,2376 00001 0D
043583,000109: 13,2377 34007 STCALL 6D # 6-7D= TIME FOR RP-TO-R
043584,000110: 13,2400 26524 SETGAMMA # GAMMA=B2/A2 FOR EARTH,1 FOR MOON B-1
043585,000111: 13,2401 73545 DLOAD SIN # COS(LONG)COS(LAT) IN MPAC
043586,000112: 13,2402 01124 LAT # UNIT RP= SIN(LONG)COS(LAT) 2-3D
043587,000113: 13,2403 65275 DMPR PDDL # PD 2 GAMMA*SIN(LAT) 0-1D
043588,000114: 13,2404 00011 GAMRP
043589,000115: 13,2405 01124 LAT # 0-1D= GAMMA*SIN(LAT) B-2
043590,000116: 13,2406 65346 COS PDDL # PD 4 2-3D=COS(LAT) B-1 TEMPORARILY
043591,000117: 13,2407 01126 LONG
043592,000118: 13,2410 57356 SIN DMPR # PD 2
043593,000119: 13,2411 71525 PDDL COS # PD 4 2-3D=SIN(LONG)COS(LAT) B-2
043594,000120: 13,2412 01124 LAT
043595,000121: 13,2413 71525 PDDL COS # PD 6 4-5D=COS(LAT) B-1 TEMPORARILY
043596,000122: 13,2414 01126 LONG
043597,000123: 13,2415 55475 DMPR VDEF # PD 4 MPAC= COS(LONG)COS(LAT) B-2
043598,000124: 13,2416 41456 UNIT PUSH # 0-5D= UNIT RP FOR RP-TO-R SUBR.
043599,000125: 13,2417 36034 STCALL ALPHAV # ALPHAV +4= SINL FOR SETRE SUBR.
043600,000126: 13,2420 26534 SETRE # RE METERS B-29
043601,000127: 13,2421 43145 DLOAD BOFF # SET MPAC=0 FOR EARTH, NON-ZERO FOR MOON
043602,000128: 13,2422 22276 ZEROVEC
043603,000129: 13,2423 01743 LUNAFLAG
043604,000130: 13,2424 26426 CALLRPRT
043605,000131: 13,2425 77746 COS # USE COS(0) TO GET NON-ZERO IN MPAC
043606,000132: 13,2426 77624 CALLRPRT CALL
043607,000133: 13,2427 51220 RP-TO-R # EXIT WITH UNIT R VECTOR IN MPAC
043608,000134: 13,2430 16034 STODL ALPHAV
043609,000135: 13,2431 03660 ERADM
043610,000136: 13,2432 74215 DAD VXSC # (RE + ALT)(UNIT R) METERS B-30
043611,000137: 13,2433 01130 ALT
043612,000138: 13,2434 02034 ALPHAV
043613,000139: 13,2435 77772 VSL1 # R METERS B-29
043614,000140: 13,2436 36034 STCALL ALPHAV # EXIT WITH R IN METERS B-29
043615,000141: 13,2437 03661 INCORPEX
043616,000142:
043617,000143: # SUBROUTINE TO COMPUTE EARTH RADIUS
043618,000144:
043619,000145: # INPUT
043620,000146: # 1/2 SIN LAT IN ALPHAV +4
043621,000147:
043622,000148: # OUTPUT
043623,000149: # EARTH RADIUS IN ERADM AND MPAC (METERS B-29)
043624,000150:
043625,000151: 13,2440 63545 GETERAD DLOAD DSQ
043626,000152: 13,2441 02040 ALPHAV +4 # SIN**2(L)
043627,000153: 13,2442 44352 SL1 BDSU
043628,000154: 13,2443 22274 DP1/2 # COS**2(L)
043629,000155: 13,2444 44275 DMPR BDSU
043630,000156: 13,2445 26461 EE
043631,000157: 13,2446 22274 DP1/2
043632,000158: 13,2447 75465 BDDV SQRT
043633,000159: 13,2450 26455 B2XSC
043634,000160: 13,2451 77622 SR4R
043635,000161: 13,2452 03660 STORE ERADM
043636,000162: 13,2453 77616 RVQ
043637,000163:
043638,000164: # THE FOLLOWING CONSTANTS WERE COMPUTED WITH A=6378166, B=6356784 METERS
043639,000165: # B2XSC= B**2 SCALED B-51
043640,000166: # B2/A2= B**2/A**2 SCALED B-1
043641,000167: # EE=(1-B**2/A**2) SCALED B-0
043642,000168:
043643,000169: 13,2454 00446 00305 B2XSC 2DEC .0179450689 # B**2 SCALED B-51
043644,000170: 13,2456 11,2273 DP1/2 = XUNIT
043645,000171: 13,2456 17711 05254 B2/A2 2DEC .9933064884 B-1 # GAMMA= B**2/A**2 B-1
043646,000172: 13,2460 00155 25250 EE 2DEC 6.6935116 E-3 # (1-B**2/A**2) B-0
043647,000173: 13,2462 00302 17755 ERAD 2DEC 6373338 B-29 # PAD RADIUS
043648,000174:
043649,000175: # ARCTAN SUBROUTINE
043650,000176:
043651,000177: # CALLING SEQUENCE
043652,000178: # SIN THETA IN SINTH B-1
043653,000179: # COS THETA IN COSTH B-1
043654,000180: # CALL ARCTAN
043655,000181:
043656,000182: # OUTPUT
043657,000183: # ARCTAN THETA IN MPAC AND THETA B-0 IN RANGE -1/2 TO +1/2
043658,000184:
043659,000185: 13,2464 77600 ARCTAN BOV
043660,000186: 13,2465 26466 CLROVFLW
043661,000187: 13,2466 63545 CLROVFLW DLOAD DSQ
043662,000188: 13,2467 00023 SINTH
043663,000189: 13,2470 63525 PDDL DSQ
043664,000190: 13,2471 00021 COSTH
043665,000191: 13,2472 77615 DAD
043666,000192: 13,2473 75454 BZE SQRT
043667,000193: 13,2474 26512 ARCTANXX # ATAN=0/0 SET THETA=0
043668,000194: 13,2475 40065 BDDV BOV
043669,000195: 13,2476 00023 SINTH
043670,000196: 13,2477 26517 ATAN=90
043671,000197: 13,2500 67542 SR1 ASIN
043672,000198: 13,2501 00025 STORE THETA
043673,000199: 13,2502 50125 PDDL BMN
043674,000200: 13,2503 00021 COSTH
043675,000201: 13,2504 26506 NEGCOS
043676,000202: 13,2505 43545 DLOAD RVQ
043677,000203: 13,2506 57545 NEGCOS DLOAD DCOMP
043678,000204: 13,2507 43244 BPL DAD
043679,000205: 13,2510 26514 NEGOUT
043680,000206: 13,2511 22274 DP1/2
043681,000207: 13,2512 00025 ARCTANXX STORE THETA
043682,000208: 13,2513 77616 RVQ
043683,000209:
043684,000210: 13,2514 52025 NEGOUT DSU GOTO
043685,000211: 13,2515 22274 DP1/2
043686,000212: 13,2516 26512 ARCTANXX
043687,000213: 13,2517 75345 ATAN=90 DLOAD SIGN
043688,000214: 13,2520 10673 LODP1/4
043689,000215: 13,2521 00023 SINTH
043690,000216: 13,2522 00025 STORE THETA
043691,000217: 13,2523 77616 RVQ
043692,000218:
043693,000219: 13,2524 11,2275 2DZERO = DPZERO
043694,000220:
043695,000221: # ..... SETGAMMA SUBROUTINE .....
043696,000222: # SUBROUTINE TO SET GAMMA FOR THE LAT-LONG AND LALOTORV SUBROUTINES
043697,000223:
043698,000224: # GAMMA = B**2/A**2 FOR EARTH (B-1)
043699,000225: # GAMMA = 1 FOR MOON (B-1)
043700,000226:
043701,000227: # CALLING SEQUENCE
043702,000228: # L CALL
043703,000229: # L+1 SETGAMMA
043704,000230:
043705,000231: # INPUT
043706,000232: # LUNAFLAG=0 FOR EARTH,=1 FOR MOON
043707,000233:
043708,000234: # OUTPUT
043709,000235: # GAMMA IN GAMRP (B-1)
043710,000236:
043711,000237: 13,2524 43145 SETGAMMA DLOAD BOFF # BRANCH FOR EARTH
043712,000238: 13,2525 26457 B2/A2 # EARTH GAMMA
043713,000239: 13,2526 01743 LUNAFLAG
043714,000240: 13,2527 26532 SETGMEX
043715,000241: 13,2530 77735 SLOAD
043716,000242: 13,2531 22274 1B1 # MOON GAMMA
043717,000243: 13,2532 00011 SETGMEX STORE GAMRP
043718,000244: 13,2533 77616 RVQ
043719,000245: 13,2534 GAMRP = 8D
043720,000246:
043721,000247: # ..... SETRE SUBROUTINE .....
043722,000248: # SUBROUTINE TO SET RE (EARTH OR MOON RADIUS)
043723,000249:
043724,000250: # RE= RM FOR MOON
043725,000251: # RE= RREF FOR FIXED EARTH RADIUS OR COMPUTED RF FOR FISCHER ELLIPSOID
043726,000252:
043727,000253: # CALLING SEQUENCE
043728,000254: # L CALL
043729,000255: # L+1 SETRE
043730,000256:
043731,000257: # SUBROUTINES USED
043732,000258: # GETERAD
043733,000259:
043734,000260: # INPUT
043735,000261: # ERADFLAG=0 FOR FIXED RE, 1 FOR COMPUTED RE
043736,000262: # ALPHAV +4= 1/2 SINL IF GETERAD IS CALLED
043737,000263: # LUNAFLAG=0 FOR EARTH,=1 FOR MOON
043738,000264:
043739,000265: # OUTPUT
043740,000266: # ERADM= 504RM FOR MOON (METERS B-29)
043741,000267: # ERADM= ERAD OR COMPUTED RF FOR EARTH (METERS B-29)
043742,000268:
043743,000269: 13,2534 71220 SETRE STQ DLOAD
043744,000270: 13,2535 00051 SETREX
043745,000271: 13,2536 26561 504RM
043746,000272: 13,2537 71214 BON DLOAD # BRANCH FOR MOON
043747,000273: 13,2540 01703 LUNAFLAG
043748,000274: 13,2541 26551 TSTRLSRM
043749,000275: 13,2542 26463 ERAD
043750,000276: 13,2543 45014 BOFF CALL # ERADFLAG=0 FOR FIXED RE, 1 FOR COMPUTED
043751,000277: 13,2544 00742 ERADFLAG
043752,000278: 13,2545 26547 SETRXX
043753,000279: 13,2546 26440 GETERAD
043754,000280: 13,2547 37660 SETRXX STCALL ERADM # EXIT WITH RE OR RM METERS B-29
043755,000281: 13,2550 00051 SETREX
043756,000282: 13,2551 77214 TSTRLSRM BON VLOAD # ERADFLAG=0, SET R0=RLS
043757,000283: 13,2552 00702 ERADFLAG # =1 R0=RM
043758,000284: 13,2553 26547 SETRXX
043759,000285: 13,2554 02025 RLS
043760,000286: 13,2555 64446 ABVAL SR2R # SCALE FROM B-27 TO B-29
043761,000287: 13,2556 77650 GOTO
043762,000288: 13,2557 26547 SETRXX
043763,000289: 13,2560 0000051 SETREX = S2
043764,000290: 13,2560 00065 01265 504RM 2DEC 1738090 B-29 # METERS B-29 (EQUATORIAL MOON RADIUS)
End of include-file LATITUDE_LONGITUDE_SUBROUTINES.agc. Parent file is MAIN.agc