Source Code
|
These source-code files are part of a reconstructed copy of Luminary 69/2,
the flown, final release of the Apollo 10 Lunar Module (LM) Apollo Guidance Computer (AGC) software.
The reconstruction is based on the source code of Luminary 69 — i.e., the
initial, unflown version, "revision 0" — of which
a contemporary listing was available. The code was then updated by incorporating the
differences between Luminary 69 and Luminary 69/2, known from other contemporary
documentation. The only such difference is the implementation in
Luminary 69/2 of the "R-2 Lunar Potential Model", the source code for which was taken
from program Luminary 99/1 (Apollo 11 LM), of which a contemporary listing was also available.
Finally, the now-reconstructed Luminary 69/2 was then validated by assembling it to
executable form and verifying that its memory banks had the correct checksums,
known from still other contemporary documentation.
Note that page numbers in the reconstructed code match those in the original Luminary 69
program listing, or in the ORBITAL INTEGRATION log section, in Luminary 99/1. Page numbers
would certainly differ somewhat in a contemporary Luminary 69/2 listing.
Moreover, annotations that were not present in the contemporary source code have been added
to the reconstructed code to justify each change in Luminary 69/2 relative to
Luminary 69. Here's a guide to the Apollo documentation referenced in those annotations:
Comments from the original source code are prefixed with a single '#' symbol,
whereas comments added later are prefixed by "##" or "###". Report any errors
noted by creating an
issue report at the Virtual AGC
project's GitHub repository.
|
021890,000002: ## Copyright: Public domain.
021891,000003: ## Filename: S-BAND_ANTENNA_FOR_LM.agc
021892,000004: ## Purpose: A section of LUM69 revision 2.
021893,000005: ## It is part of the reconstructed source code for the flown
021894,000006: ## version of the flight software for the Lunar Module's (LM)
021895,000007: ## Apollo Guidance Computer (AGC) for Apollo 10. The code has
021896,000008: ## been recreated from a copy of Luminary revsion 069, using
021897,000009: ## changes present in Luminary 099 which were described in
021898,000010: ## Luminary memos 75 and 78. The code has been adapted such
021899,000011: ## that the resulting bugger words exactly match those specified
021900,000012: ## for LUM69 revision 2 in NASA drawing 2021152B, which gives
021901,000013: ## relatively high confidence that the reconstruction is correct.
021902,000014: ## Reference: pp. 498-501
021903,000015: ## Assembler: yaYUL
021904,000016: ## Contact: Ron Burkey <info@sandroid.org>.
021905,000017: ## Website: www.ibiblio.org/apollo/index.html
021906,000018: ## Mod history: 2019-07-27 MAS Created from Luminary 69.
021907,000019:
|
|
Page 498
|
021909,000021: # SUBROUTINE NAME: R05 - S-BAND ANTENNA FOR LM
021910,000022:
021911,000023: # MOD0 BY T. JAMES
021912,000024: # MOD1 BY P. SHAKIR
021913,000025:
021914,000026: # FUNCTIONAL DESCRIPTION
021915,000027:
021916,000028: # THE S-BAND ANTENNA ROUTINE, R05, COMPUTES AND DISPLAYS THE PITCH AND
021917,000029: # YAW ANTENNA GIMBAL ANGLES REQUIRED TO POINT THE LM STEERABLE ANTENNA
021918,000030: # TOWARD THE CENTER OF THE EARTH. THIS ROUTINE IS SELECTED BY THE ASTRO-
021919,000031: # NAUT VIA DSKY ENTRY DURING COASTING FLIGHT OR WHEN THE LM IS ON THE MOON
021920,000032: # SURFACE. THE EARTH OR MOON REFERENCE COORDINATE SYSTEM IS USED DEPENDING
021921,000033: # ON WHETHER THE LM IS ABOUT TO ENTER OR HAS ALREADY ENTERED THE MOON
021922,000034: # SPHERE OF INFLUENCE, RESPECTIVELY
021923,000035:
021924,000036: # TO CALL SUBROUTINE, ASTRONAUT KEYS IN V 64 E
021925,000037:
021926,000038: # SUBROUTINES CALLED-
021927,000039: # R02BOTH
021928,000040: # INTPRET
021929,000041: # LOADTIME
021930,000042: # LEMCONIC
021931,000043: # LUNPOS
021932,000044: # CDUTRIG
021933,000045: # *SMNB*
021934,000046: # BANKCALL
021935,000047: # B5OFF
021936,000048: # ENDOFJOB
021937,000049: # BLANKET
021938,000050:
021939,000051: # RETURNS WITH
021940,000052: # PITCH ANGLE IN PITCHANG REV. B0
021941,000053: # YAW ANGLE IN YAWANG REV. B0
021942,000054:
021943,000055: # ERASABLES USED
021944,000056: # PITCHANG
021945,000057: # YAWANG
021946,000058: # RLM
021947,000059: # VAC AREA
021948,000060:
021949,000061: 41,3731 BANK 41
021950,000062: 42,2000 SETLOC SBAND
021951,000063: 42,2000 BANK
021952,000064:
021953,000065: 42,3602 E7,1467 EBANK= WHOCARES
021954,000066: 42,3602 COUNT* $$/R05
021955,000067: 42,3602 04616 SBANDANT TC BANKCALL
|
|
Page 499
|
021957,000069: 42,3603 11175 CADR R02BOTH # CHECK IF IMU IS ON AND ALIGNED
021958,000070: 42,3604 06036 TC INTPRET
021959,000071: 42,3605 47001 SETPD RTB
021960,000072: 42,3606 00001 0D
021961,000073: 42,3607 21462 LOADTIME # PICK UP CURRENT TIME
021962,000074: 42,3610 34041 STCALL TDEC1 # ADVANCE INTEGRATION TO TIME IN TDEC1
021963,000075: 42,3611 27100 LEMCONIC # USING CONIC INTEGRATION
021964,000076: 42,3612 46135 SLOAD BHIZ
021965,000077: 42,3613 00050 X2 # X2 =0 EARTH SPHERE, X2 =2 MOON SPHERE
021966,000078: 42,3614 65632 CONV4
021967,000079: 42,3615 77775 VLOAD
021968,000080: 42,3616 00001 RATT
021969,000081: 42,3617 16211 STODL RLM
021970,000082: 42,3620 00015 TAT
021971,000083: 42,3621 77624 CONV3 CALL
021972,000084: 42,3622 33663 LUNPOS # UNIT POSITION VECTOR FROM EARTH TO MOON
021973,000085: 42,3623 74375 VLOAD VXSC
021974,000086: 42,3624 02723 VMOON
021975,000087: 42,3625 24001 REMDIST # MEAN DISTANCE FROM EARTH TO MOON
021976,000088: 42,3626 53372 VSL1 VAD
021977,000089: 42,3627 02211 RLM
021978,000090: 42,3630 77650 GOTO
021979,000091: 42,3631 65634 CONV5
021980,000092: 42,3632 77775 CONV4 VLOAD
021981,000093: 42,3633 00001 RATT # UE = -UNIT(RATT) EARTH SPHERE
021982,000094: 42,3634 53401 CONV5 SETPD UNIT # UE = -UNIT((REM)(UEM) + RL) MOON SPHERE
021983,000095: 42,3635 00001 0D # SET PL POINTER TO 0
021984,000096: 42,3636 45076 VCOMP CALL
021985,000097: 42,3637 47443 CDUTRIG # COMPUTE SINES AND COSINES OF CDU ANGLES
021986,000098: 42,3640 76521 MXV VSL1 # TRANSFORM REF. COORDINATE SYSTEM TO
021987,000099: 42,3641 01734 REFSMMAT # STABLE MEMBER B-1 X B-1 X B+1 = B-1
021988,000100: 42,3642 71206 PUSH DLOAD # 8D
021989,000101: 42,3643 06424 HI6ZEROS
021990,000102: 42,3644 02205 STORE PITCHANG
021991,000103: 42,3645 26207 STOVL YAWANG # ZERO OUT ANGLES
021992,000104: 42,3646 77624 CALL
021993,000105: 42,3647 47575 *SMNB*
021994,000106: 42,3650 16211 STODL RLM # PRE-MULTIPLY RLM BY (NBSA) MATRIX(B0)
021995,000107: 42,3651 02213 RLM +2
021996,000108: 42,3652 45206 PUSH DSU
021997,000109: 42,3653 02211 RLM
021998,000110: 42,3654 77605 DMP
021999,000111: 42,3655 25765 1OVSQRT2
022000,000112: 42,3656 16213 STODL RLM +2
022001,000113: 42,3657 41215 DAD DMP
022002,000114: 42,3660 02211 RLM
022003,000115: 42,3661 25765 1OVSQRT2
022004,000116: 42,3662 26211 STOVL RLM # R B-1
022005,000117: 42,3663 02211 RLM
022006,000118: 42,3664 63256 UNIT PDVL
|
|
Page 500
|
022008,000120: 42,3665 02211 RLM
022009,000121: 42,3666 72431 VPROJ VSL2 # PROJECTION OF R ONTO LM XZ PLANE
022010,000122: 42,3667 06420 HIUNITY
022011,000123: 42,3670 40045 BVSU BOV # CLEAR OVERFLOW INDICATOR IF ON
022012,000124: 42,3671 02211 RLM
022013,000125: 42,3672 65673 COVCNV
022014,000126: 42,3673 40056 COVCNV UNIT BOV # EXIT ON OVERFLOW
022015,000127: 42,3674 65741 SBANDEX
022016,000128: 42,3675 47206 PUSH VXV # URP VECTOR B-1
022017,000129: 42,3676 06416 HIUNITZ
022018,000130: 42,3677 57572 VSL1 VCOMP # UZ X URP = -(URP X UZ)
022019,000131: 42,3700 02211 STORE RLM # X VEC B-1
022020,000132: 42,3701 63241 DOT PDVL # SGN(X.UY) UNSCALED
022021,000133: 42,3702 06420 HIUNITY
022022,000134: 42,3703 02211 RLM
022023,000135: 42,3704 75246 ABVAL SIGN
022024,000136: 42,3705 77736 ASIN # ASIN((SGN(X.UY))ABV(X)) REV B0
022025,000137: 42,3706 26205 STOVL PITCHANG
022026,000138: 42,3707 00007 URP
022027,000139: 42,3710 51041 DOT BPL
022028,000140: 42,3711 06416 HIUNITZ
022029,000141: 42,3712 65717 NOADJUST # YES, -90 TO +90
022030,000142: 42,3713 45345 DLOAD DSU
022031,000143: 42,3714 06422 HIDPHALF
022032,000144: 42,3715 02205 PITCHANG
022033,000145: 42,3716 02205 STORE PITCHANG
022034,000146: 42,3717 47375 NOADJUST VLOAD VXV
022035,000147: 42,3720 00001 UR # Z = (UR X URP)
022036,000148: 42,3721 00007 URP
022037,000149: 42,3722 77772 VSL1
022038,000150: 42,3723 16211 STODL RLM # Z VEC B-1
022039,000151: 42,3724 02205 PITCHANG
022040,000152: 42,3725 74356 SIN VXSC
022041,000153: 42,3726 06416 HIUNITZ
022042,000154: 42,3727 71525 PDDL COS
022043,000155: 42,3730 02205 PITCHANG
022044,000156: 42,3731 52361 VXSC VSU
022045,000157: 42,3732 06422 HIUNITX # (UX COS ALPHA) - (UZ SIN ALPHA)
022046,000158: 42,3733 63241 DOT PDVL # YAW.Z
022047,000159: 42,3734 02211 RLM
022048,000160: 42,3735 02211 RLM
022049,000161: 42,3736 75246 ABVAL SIGN
022050,000162: 42,3737 77736 ASIN
022051,000163: 42,3740 02207 STORE YAWANG
022052,000164: 42,3741 77776 SBANDEX EXIT
022053,000165: 42,3742 31044 CA EXTVBACT
022054,000166: 42,3743 74747 MASK BIT5 # IS BIT5 STILL ON
022055,000167: 42,3744 00006 EXTEND
022056,000168: 42,3745 15472 BZF ENDEXT # NO
022057,000169: 42,3746 35017 CAF PRIO5
|
|
Page 501
|
022059,000171: 42,3747 05146 TC PRIOCHNG
022060,000172: 42,3750 33763 CAF V06N51 # DISPLAY ANGLES
022061,000173: 42,3751 04616 TC BANKCALL
022062,000174: 42,3752 20231 CADR GOMARKFR
022063,000175: 42,3753 05563 TC B5OFF # TERMINATE
022064,000176: 42,3754 05563 TC B5OFF # PROCEED
022065,000177: 42,3755 05155 TC ENDOFJOB # RECYCLE
022066,000178: 42,3756 34751 CAF BIT3 # IMMEDIATE RETURN
022067,000179: 42,3757 05464 TC BLANKET # BLANK R3
022068,000180: 42,3760 34740 CAF PRIO4
022069,000181: 42,3761 05146 TC PRIOCHNG
022070,000182: 42,3762 03604 TC SBANDANT +2 # YES, CONTINUE DISPLAYING ANGLES
022071,000183: 42,3763 01463 V06N51 VN 0651
022072,000184: 42,3764 26501 07463 1OVSQRT2 2DEC .7071067815 # 1/SQRT(2)
022073,000185:
022074,000186: 42,3766 UR EQUALS 0D
022075,000187: 42,3766 URP EQUALS 6D
022076,000188: 42,3766 30,2000 SBANK= LOWSUPER
End of include-file S-BAND_ANTENNA_FOR_LM.agc. Parent file is MAIN.agc