Source Code
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These source-code files were transcribed from a printout in Don Eyles's personal
collection, scanned by archive.org, and financially sponsored by Linden Sims.
A team of volunteers performed the transcription and proof-reading. The scanned
page images are available at
the Virtual AGC Project website, as well as higher-quality (but much larger)
images at
the Virtual AGC Project's collection in the Internet Archive. Report any problems by creating
"issues" at
the Virtual AGC Project's GitHub Repository. Notations on the program listing read, in part: GAP: ASSEMBLE REVISION 56 OF AGC PROGRAM ZERLINA BY ZOROASTER 9:12 OCT. 21,1970Note that the date is the date of the printout, not the date of the program revision. |
048955,000002: ## Copyright: Public domain.
048956,000003: ## Filename: LATITUDE_LONGITUDE_SUBROUTINES.agc
048957,000004: ## Purpose: A log section of Zerlina 56, the final revision of
048958,000005: ## Don Eyles's offline development program for the variable
048959,000006: ## guidance period servicer. It also includes a new P66 with LPD
048960,000007: ## (Landing Point Designator) capability, based on an idea of John
048961,000008: ## Young's. Neither of these advanced features were actually flown,
048962,000009: ## but Zerlina was also the birthplace of other big improvements to
048963,000010: ## Luminary including the terrain model and new (Luminary 1E)
048964,000011: ## analog display programs. Zerlina was branched off of Luminary 145,
048965,000012: ## and revision 56 includes all changes up to and including Luminary
048966,000013: ## 183. It is therefore quite close to the Apollo 14 program,
048967,000014: ## Luminary 178, where not modified with new features.
048968,000015: ## Reference: pp. 1124-1130
048969,000016: ## Assembler: yaYUL
048970,000017: ## Contact: Ron Burkey <info@sandroid.org>.
048971,000018: ## Website: www.ibiblio.org/apollo/index.html
048972,000019: ## Mod history: 2017-07-28 MAS Created from Luminary 210.
048973,000020: ## 2017-08-28 MAS Updated for Zerlina 56.
048974,000021:
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Page 1124 |
048976,000023: # SUBROUTINE TO CONVERT RAD VECTOR AT GIVEN TIME TO LAT,LONG AND ALT
048977,000024:
048978,000025: # CALLING SEQUENCE
048979,000026:
048980,000027: # L-1 CALL
048981,000028: # L LAT-LONG
048982,000029: # SUBROUTINES USED
048983,000030:
048984,000031: # R-TO-RP,ARCTAN,SETGAMMA,SETRE
048985,000032: # ERASABLE INIT. REQ.
048986,000033:
048987,000034: # AXO,-AYO,AZO,TEPHEM (SET AT LAUNCH TIME)
048988,000035: # ALPHAV = POSITION VECTOR METERS B-29
048989,000036: # MPAC-- TIME (CSECS B-28)
048990,000037: # ERADFLAG =1, TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
048991,000038: # LUNAFLAG=0 FOR EARTH,1 FOR MOON
048992,000039: # OUTPUT
048993,000040:
048994,000041: # LATITUDE IN LAT (REVS. B-0)
048995,000042: # LONGITUDE IN LONG (REVS. B-0)
048996,000043: # ALTITUDE IN ALT METERS B-29
048997,000044: 30,3761 BANK 30
048998,000045: 13,2000 SETLOC LATLONG
048999,000046: 13,2000 BANK
049000,000047:
049001,000048: 13,2347 COUNT* $$/LT-LG
049002,000049: 13,2347 E4,1431 EBANK= ALPHAV
049003,000050: 13,2347 40220 LAT-LONG STQ SETPD
049004,000051: 13,2350 03674 INCORPEX
049005,000052: 13,2351 00001 0D
049006,000053: 13,2352 24007 STOVL 6D # SAVE TIME IN 6-7D FOR R-TO-RP
049007,000054: 13,2353 02032 ALPHAV
049008,000055: 13,2354 51406 PUSH ABVAL # 0-5D= R FOR R-TO-RP
049009,000056: 13,2355 16070 STODL ALPHAM # ABS. VALUE OF R FOR ALT FORMULA BELOW
049010,000057: 13,2356 24007 ZEROVEC # SET MPAC=0 FOR EARTH,NON-ZERO FOR MOON
049011,000058: 13,2357 71414 BOFF COS # USE COS(0) TO GET NON-ZERO IN MPAC
049012,000059: 13,2360 01743 LUNAFLAG # 0=EARTH,1=MOON
049013,000060: 13,2361 26362 CALLRTRP
049014,000061: 13,2362 77624 CALLRTRP CALL
049015,000062: 13,2363 51644 R-TO-RP # RP VECTOR CONVERTED FROM R B-29
049016,000063: 13,2364 77656 UNIT # UNIT RP B-1
049017,000064: 13,2365 36032 STCALL ALPHAV # U2= 1/2 SINL FOR SETRE SUBR BELOW
049018,000065: 13,2366 26546 SETGAMMA # SET GAMMA=B2/A2 FOR EARTH,=1 FOR MOON
049019,000066: 13,2367 77624 CALL # SCALED B-1
049020,000067: 13,2370 26556 SETRE # CALC RE METERS B-29
049021,000068: 13,2371 63545 DLOAD DSQ
049022,000069: 13,2372 02032 ALPHAV
049023,000070: 13,2373 63525 PDDL DSQ
049024,000071: 13,2374 02034 ALPHAV +2
049025,000072: 13,2375 75415 DAD SQRT
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Page 1125 |
049027,000074: 13,2376 76405 DMP SL1R
049028,000075: 13,2377 00011 GAMRP
049029,000076: 13,2400 14021 STODL COSTH # COS(LAT) B-1
049030,000077: 13,2401 02036 ALPHAV +4
049031,000078: 13,2402 34023 STCALL SINTH # SIN(LAT) B-1
049032,000079: 13,2403 26506 ARCTAN
049033,000080: 13,2404 15120 STODL LAT # LAT B0
049034,000081: 13,2405 02032 ALPHAV
049035,000082: 13,2406 14021 STODL COSTH # COS(LONG) B-1
049036,000083: 13,2407 02034 ALPHAV +2
049037,000084: 13,2410 34023 STCALL SINTH # SIN(LONG) B-1
049038,000085: 13,2411 26506 ARCTAN
049039,000086: 13,2412 15122 STODL LONG # LONG. REVS B-0 IN RANGE -1/2 TO 1/2
049040,000087: 13,2413 02070 ALPHAM
049041,000088: 13,2414 77625 DSU # ALT= R-RE METERS B-29
049042,000089: 13,2415 03673 ERADM
049043,000090: 13,2416 35124 STCALL ALT # EXIT WITH ALT METERS B-29
049044,000091: 13,2417 03674 INCORPEX
049045,000092:
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Page 1126 |
049047,000094: # SUBROUTINE TO CONVERT LAT,LONG,ALT AT GIVEN TIME TO RADIUS VECTOR
049048,000095: # CALLING SEQUENCE
049049,000096:
049050,000097: # L-1 CALL
049051,000098: # L LALOTORV
049052,000099: # SUBROUTINES USED
049053,000100:
049054,000101: # SETGAMMA,SETRE,RP-TO-R
049055,000102: # ERASABLE INIT. REQ.
049056,000103:
049057,000104: # AXO,AYO,AZO,TEPHEM SET AT LAUNCH TIME
049058,000105: # LAT-- LATITUDE (REVS B0)
049059,000106: # LONG-- LONGITUDE (REVS B0)
049060,000107: # ALT--ALTITUDE (METERS) B-29
049061,000108: # MPAC-- TIME (CSECS B-28)
049062,000109: # ERADFLAG =1 TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
049063,000110: # LUNAFLAG=0 FOR EARTH,1 FOR MOON
049064,000111: # OUTPUT
049065,000112:
049066,000113: # R-VECTOR IN ALPHAV (METERS B-29)
049067,000114: 13,2420 40220 LALOTORV STQ SETPD # LAT,LONG,ALT TO R VECTOR
049068,000115: 13,2421 03674 INCORPEX
049069,000116: 13,2422 00001 0D
049070,000117: 13,2423 34007 STCALL 6D # 6-7D= TIME FOR RP-TO-R
049071,000118: 13,2424 26546 SETGAMMA # GAMMA=B2/A2 FOR EARTH,1 FOR MOON B-1
049072,000119: 13,2425 73545 DLOAD SIN # COS(LONG)COS(LAT) IN MPAC
049073,000120: 13,2426 01120 LAT # UNIT RP= SIN(LONG)COS(LAT) 2-3D
049074,000121: 13,2427 65275 DMPR PDDL # PD 2 GAMMA*SIN(LAT) 0-1D
049075,000122: 13,2430 00011 GAMRP
049076,000123: 13,2431 01120 LAT # 0-1D= GAMMA*SIN(LAT) B-2
049077,000124: 13,2432 65346 COS PDDL # PD4 2-3D=COS(LAT) B-1 TEMPORARILY
049078,000125: 13,2433 01122 LONG
049079,000126: 13,2434 57356 SIN DMPR # PD 2
049080,000127: 13,2435 71525 PDDL COS # PD 4 2-3D=SIN(LONG)COS(LAT) B-2
049081,000128: 13,2436 01120 LAT
049082,000129: 13,2437 71525 PDDL COS # PD 6 4-5D=COS(LAT) B-1 TEMPORARILY
049083,000130: 13,2440 01122 LONG
049084,000131: 13,2441 55475 DMPR VDEF # PD 4 MPAC= COS(LONG)COS(LAT) B-2
049085,000132: 13,2442 41456 UNIT PUSH # 0-5D= UNIT RP FOR RP-TO-R SUBR.
049086,000133: 13,2443 36032 STCALL ALPHAV # ALPHAV +4= SINL FOR SETRE SUBR.
049087,000134: 13,2444 26556 SETRE # RE METERS B-29
049088,000135: 13,2445 43145 DLOAD BOFF # SET MPAC=0 FOR EARTH,NON-ZERO FOR MOON
049089,000136: 13,2446 24007 ZEROVEC
049090,000137: 13,2447 01743 LUNAFLAG
049091,000138: 13,2450 26452 CALLRPRT
049092,000139: 13,2451 77746 COS # USE COS(0) TO GET NON-ZERO IN MPAC
049093,000140: 13,2452 77624 CALLRPRT CALL
049094,000141: 13,2453 55720 RP-TO-R # EXIT WITH UNIT R VECTOR IN MPAC
049095,000142: 13,2454 16032 STODL ALPHAV
049096,000143: 13,2455 03673 ERADM
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Page 1127 |
049098,000145: 13,2456 74215 DAD VXSC # (RE + ALT)(UNIT R) METERS B-30
049099,000146: 13,2457 01124 ALT
049100,000147: 13,2460 02032 ALPHAV
049101,000148: 13,2461 77772 VSL1 # R METERS B-29
049102,000149: 13,2462 36032 STCALL ALPHAV # EXIT WITH R IN METERS B-29
049103,000150: 13,2463 03674 INCORPEX
049104,000151: # SUBROUTINE TO COMPUTE EARTH RADIUS
049105,000152:
049106,000153: # INPUT
049107,000154:
049108,000155: # 1/2 SIN LAT IN ALPHAV +4
049109,000156:
049110,000157: # OUTPUT
049111,000158:
049112,000159: # EARTH RADIUS IN ERADM AND MPAC (METERS B-29)
049113,000160:
049114,000161: 13,2464 63545 GETERAD DLOAD DSQ
049115,000162: 13,2465 02036 ALPHAV +4 # SIN**2(L)
049116,000163: 13,2466 44352 SL1 BDSU
049117,000164: 13,2467 24005 DP1/2 # COS**2(L)
049118,000165: 13,2470 44275 DMPR BDSU
049119,000166: 13,2471 26505 EE
049120,000167: 13,2472 24005 DP1/2
049121,000168: 13,2473 75465 BDDV SQRT
049122,000169: 13,2474 26501 B2XSC
049123,000170: 13,2475 77622 SR4R
049124,000171: 13,2476 03673 STORE ERADM
049125,000172: 13,2477 77616 RVQ
049126,000173:
049127,000174: # THE FOLLOWING CONSTANTS WERE COMPUTED WITH A=6378166,B=6356784 METERS
049128,000175: # B2XSC= B**2 SCALED B-51
049129,000176: # B2/A2= B**2/A**2 SCALED B-1
049130,000177: # EE=(1-B**2/A**2) SCALED B-0
049131,000178: 13,2500 00446 00305 B2XSC 2DEC .0179450689 # B**2 SCALED B-51
049132,000179:
049133,000180: 13,2502 12,2004 DP1/2 = XUNIT
049134,000181: 13,2502 17711 05254 B2/A2 2DEC .9933064884 B-1 # GAMMA= B**2/A**2 B-1
049135,000182:
049136,000183: 13,2504 00155 25250 EE 2DEC 6.6935116 E-3 # (1-B**2/A**2) B-0
049137,000184:
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Page 1128 |
049139,000186: # ARCTAN SUBROUTINE
049140,000187:
049141,000188:
049142,000189: # CALLING SEQUENCE
049143,000190:
049144,000191: # SIN THETA IN SINTH B-1
049145,000192: # COS THETA IN COSTH B-1
049146,000193: # CALL ARCTAN
049147,000194:
049148,000195: # OUTPUT
049149,000196: # ARCTAN THETA IN MPAC AND THETA B-0 IN RANGE -1/2 TO +1/2
049150,000197:
049151,000198:
049152,000199: 13,2506 77600 ARCTAN BOV
049153,000200: 13,2507 26510 CLROVFLW
049154,000201: 13,2510 63545 CLROVFLW DLOAD DSQ
049155,000202: 13,2511 00023 SINTH
049156,000203: 13,2512 63525 PDDL DSQ
049157,000204: 13,2513 00021 COSTH
049158,000205: 13,2514 77615 DAD
049159,000206: 13,2515 75454 BZE SQRT
049160,000207: 13,2516 26534 ARCTANXX # ATAN=0/0 SET THETA=0
049161,000208: 13,2517 40065 BDDV BOV
049162,000209: 13,2520 00023 SINTH
049163,000210: 13,2521 26541 ATAN=90
049164,000211: 13,2522 67542 SR1 ASIN
049165,000212: 13,2523 00025 STORE THETA
049166,000213: 13,2524 50125 PDDL BMN
049167,000214: 13,2525 00021 COSTH
049168,000215: 13,2526 26530 NEGCOS
049169,000216: 13,2527 43545 DLOAD RVQ
049170,000217: 13,2530 57545 NEGCOS DLOAD DCOMP
049171,000218: 13,2531 43244 BPL DAD
049172,000219: 13,2532 26536 NEGOUT
049173,000220: 13,2533 24005 DP1/2
049174,000221: 13,2534 00025 ARCTANXX STORE THETA
049175,000222: 13,2535 77616 RVQ
049176,000223:
049177,000224: 13,2536 52025 NEGOUT DSU GOTO
049178,000225: 13,2537 24005 DP1/2
049179,000226: 13,2540 26534 ARCTANXX
049180,000227: 13,2541 75345 ATAN=90 DLOAD SIGN
049181,000228: 13,2542 11011 LODP1/4
049182,000229: 13,2543 00023 SINTH
049183,000230: 13,2544 00025 STORE THETA
049184,000231: 13,2545 77616 RVQ
049185,000232:
049186,000233: 13,2546 12,2006 2DZERO = DPZERO
049187,000234:
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Page 1129 |
049189,000236: # ..... SETGAMMA SUBROUTINE .....
049190,000237: # SUBROUTINE TO SET GAMMA FOR THE LAT-LONG AND LALOTORV SUBROUTINES
049191,000238:
049192,000239: # GAMMA = B**2/A**2 FOR EARTH (B-1)
049193,000240: # GAMMA = 1 FOR MOON (B-1)
049194,000241:
049195,000242: # CALLING SEQUENCE
049196,000243: # L CALL
049197,000244: # L+1 SETGAMMA
049198,000245:
049199,000246: # INPUT
049200,000247: # LUNAFLAG=0 FOR EARTH,=1 FOR MOON
049201,000248:
049202,000249: # OUTPUT
049203,000250: # GAMMA IN GAMRP (B-1)
049204,000251:
049205,000252: 13,2546 43145 SETGAMMA DLOAD BOFF # BRANCH FOR EARTH
049206,000253: 13,2547 26503 B2/A2 # EARTH GAMMA
049207,000254: 13,2550 01743 LUNAFLAG
049208,000255: 13,2551 26554 SETGMEX
049209,000256: 13,2552 77735 SLOAD
049210,000257: 13,2553 24005 1B1 # MOON GAMMA
049211,000258: 13,2554 00011 SETGMEX STORE GAMRP
049212,000259: 13,2555 77616 RVQ
049213,000260: 13,2556 GAMRP = 8D
049214,000261:
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Page 1130 |
049216,000263: # .....SETRE SUBROUTINE .....
049217,000264: # SUBROUTINE TO SET RE (EARTH OR MOON RADIUS)
049218,000265:
049219,000266: # RE= RM FOR MOON
049220,000267: # RE= RREF FOR FIXED EARTH RADIUS OR COMPUTED RF FOR FISCHER ELLIPSOID
049221,000268:
049222,000269: # CALLING SEQUENCE
049223,000270: # L CALL
049224,000271: # L+1 SETRE
049225,000272:
049226,000273: # SUBROUTINES USED
049227,000274: # GETERAD
049228,000275:
049229,000276: # INPUT
049230,000277: # ERADFLAG=0 FOR FIXED RE, 1 FOR COMPUTED RE
049231,000278: # ALPHAV +4= 1/2 SINL IF GETERAD IS CALLED
049232,000279: # LUNAFLAG=0 FOR EARTH,=1 FOR MOON
049233,000280:
049234,000281: # OUTPUT
049235,000282: # ERADM= 504RM FOR MOON (METERS B-29)
049236,000283: # ERADM= ERAD OR COMPUTED RF FOR EARTH (METERS B-29)
049237,000284:
049238,000285: 13,2556 71220 SETRE STQ DLOAD
049239,000286: 13,2557 00051 SETREX
049240,000287: 13,2560 10003 504RM
049241,000288: 13,2561 71214 BON DLOAD # BRANCH FOR MOON
049242,000289: 13,2562 01703 LUNAFLAG
049243,000290: 13,2563 26573 TSTRLSRM
049244,000291: 13,2564 10001 ERAD
049245,000292: 13,2565 45014 BOFF CALL # ERADFLAG=0 FOR FIXED RE,1 FOR COMPUTED
049246,000293: 13,2566 00742 ERADFLAG
049247,000294: 13,2567 26571 SETRXX
049248,000295: 13,2570 26464 GETERAD
049249,000296: 13,2571 37673 SETRXX STCALL ERADM # EXIT WITH RE OR RM METERS B-29
049250,000297: 13,2572 00051 SETREX
049251,000298: 13,2573 77214 TSTRLSRM BON VLOAD # ERADFLAG=0,SET R0=RLS
049252,000299: 13,2574 00702 ERADFLAG # =1 R0=RM
049253,000300: 13,2575 26571 SETRXX
049254,000301: 13,2576 02021 RLS
049255,000302: 13,2577 64446 ABVAL SR2R # SCALE FROM B-27 TO B-29
049256,000303: 13,2600 77650 GOTO
049257,000304: 13,2601 26571 SETRXX
049258,000305: 13,2602 0000051 SETREX = S2
End of include-file LATITUDE_LONGITUDE_SUBROUTINES.agc. Parent file is MAIN.agc