Source Code
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This is a reconstruction of the AGC program Luminary 99 Rev 0. It was the third release
of the Lunar Module flight software targeted for use in Apollo 11, after Luminary 96 and 97.
A bug (which had been around since at least Apollo 10, Luminary 69) was
discovered in Rev 0 shortly before the Apollo 11 flight, resulting in a last minute
revision into Rev 1,
which is what actually flew rather than
the Rev 0 presented here. A hardcopy of Rev 0 is known to
exist — it belonged to AGC developer Allan Klumpp for many years — but
unfortunately the Virtual AGC Project has not had access to that hardcopy. Thus
the code you see here had been reconstructed (we believe accurately) rather than
transcribed. The first step of the reconstruction of the Rev 0 source code was
the transcription of the Rev 1 source code from a hardcopy in the MIT Museum collection.
The process of reverting the active portion of the source code (i.e., other than
program comments) from Rev 1 to Rev 0 was very minor, consisting
only of moving the position of the STARTSB1 label in
FRESH START AND RESTART. Allan had previously given
us the checksums of the memory banks of Rev 0, and we have verified the program presented here has checksums
identical to all banks of Allan's listing of Rev 0. The notations on Allan's Rev 0 program listing read,
in part:GAP: ASSEMBLE REVISION 099 OF AGC PROGRAM LUMINARY BY NASA 2021112-051 A single program comment is known to differ between Rev 0 and Rev 1, but these are harder to reconstruct and verify than changes to the active portion of the code. Thus it is possible that there are additional differences between the program comments in Rev 0 and Rev 1 that are unknown to us, and therefore are not reflected in the code presented here. |
061162,000002: ## Copyright: Public domain.
061163,000003: ## Filename: RTB_OP_CODES.agc
061164,000004: ## Purpose: Part of the reconstructed source code for LMY99 Rev 0,
061165,000005: ## otherwise known as Luminary Rev 99, the third release
061166,000006: ## of the Apollo Guidance Computer (AGC) software for Apollo 11.
061167,000007: ## It differs from LMY99 Rev 1 (the flown version) only in the
061168,000008: ## placement of a single label. The corrections shown here have
061169,000009: ## been verified to have the same bank checksums as AGC developer
061170,000010: ## Allan Klumpp's copy of Luminary Rev 99, and so are believed
061171,000011: ## to be accurate. This file is intended to be a faithful
061172,000012: ## recreation, except that the code format has been changed to
061173,000013: ## conform to the requirements of the yaYUL assembler rather than
061174,000014: ## the original YUL assembler.
061175,000015: ##
061176,000016: ## Assembler: yaYUL
061177,000017: ## Contact: Ron Burkey <info@sandroid.org>.
061178,000018: ## Website: www.ibiblio.org/apollo.
061179,000019: ## Pages: 1397-1401
061180,000020: ## Mod history: 2009-05-10 SN (Sergio Navarro). Started adapting
061181,000021: ## from the Luminary131/ file of the same
061182,000022: ## name, using Luminary099 page images.
061183,000023: ## 2016-12-18 RSB Proofed text comments with octopus/ProoferComments
061184,000024: ## and corrected the errors found.
061185,000025: ## 2017-08-01 MAS Created from LMY99 Rev 1.
061186,000026:
061187,000027: ## This source code has been transcribed or otherwise adapted from
061188,000028: ## digitized images of a hardcopy from the MIT Museum. The digitization
061189,000029: ## was performed by Paul Fjeld, and arranged for by Deborah Douglas of
061190,000030: ## the Museum. Many thanks to both. The images (with suitable reduction
061191,000031: ## in storage size and consequent reduction in image quality as well) are
061192,000032: ## available online at www.ibiblio.org/apollo. If for some reason you
061193,000033: ## find that the images are illegible, contact me at info@sandroid.org
061194,000034: ## about getting access to the (much) higher-quality images which Paul
061195,000035: ## actually created.
061196,000036: ##
061197,000037: ## The code has been modified to match LMY99 Revision 0, otherwise
061198,000038: ## known as Luminary Revision 99, the Apollo 11 software release preceeding
061199,000039: ## the listing from which it was transcribed. It has been verified to
061200,000040: ## contain the same bank checksums as AGC developer Allan Klumpp's listing
061201,000041: ## of Luminary Revision 99 (for which we do not have scans).
061202,000042: ##
061203,000043: ## Notations on Allan Klumpp's listing read, in part:
061204,000044: ##
061205,000045: ## ASSEMBLE REVISION 099 OF AGC PROGRAM LUMINARY BY NASA 2021112-51
061206,000046:
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Page 1397 |
061208,000048: 22,3773 BANK 22
061209,000049: 10,2000 SETLOC RTBCODES
061210,000050: 10,2000 BANK
061211,000051:
061212,000052: 10,3573 E5,1664 EBANK= XNB
061213,000053: 10,3573 COUNT* $$/RTB
061214,000054:
061215,000055: # LOAD TIME2, TIME1 INTO MPAC:
061216,000056:
061217,000057: 10,3573 00006 LOADTIME EXTEND
061218,000058: 10,3574 30025 DCA TIME2
061219,000059: 10,3575 16055 TCF SLOAD2
061220,000060:
061221,000061: # CONVERT THE SINGLE PRECISION 2'S COMPLEMENT NUMBER ARRIVING IN MPAC (SCALED IN HALF-REVOLUTIONS) TO A
061222,000062: # DP 1'S COMPLEMENT NUMBER SCALED IN REVOLUTIONS.
061223,000063:
061224,000064: 10,3576 10154 CDULOGIC CCS MPAC
061225,000065: 10,3577 34755 CAF ZERO
061226,000066: 10,3600 13603 TCF +3
061227,000067: 10,3601 13602 NOOP
061228,000068: 10,3602 44736 CS HALF
061229,000069:
061230,000070: 10,3603 54155 TS MPAC +1
061231,000071: 10,3604 34755 CAF ZERO
061232,000072: 10,3605 56154 XCH MPAC
061233,000073: 10,3606 00006 EXTEND
061234,000074: 10,3607 74736 MP HALF
061235,000075: 10,3610 20155 DAS MPAC
061236,000076: 10,3611 16061 TCF DANZIG # MODE IS ALREADY AT DOUBLE-PRECISION
061237,000077:
061238,000078: # FORCE TP SIGN AGREEMENT IN MPAC:
061239,000079:
061240,000080: 10,3612 07257 SGNAGREE TC TPAGREE
061241,000081: 10,3613 16061 TCF DANZIG
061242,000082:
061243,000083: # CONVERT THE DP 1'S COMPLEMENT ANGLE SCALED IN REVOLUTIONS TO A SINGLE PRECISION 2'S COMPLEMENT ANGLE
061244,000084: # SCALED IN HALF-REVOLUTIONS.
061245,000085:
061246,000086: 10,3614 03644 1STO2S TC 1TO2SUB
061247,000087: 10,3615 34755 CAF ZERO
061248,000088: 10,3616 54155 TS MPAC +1
061249,000089: 10,3617 16060 TCF NEWMODE
061250,000090:
061251,000091: # DO 1STO2S ON A VECTOR OF ANGLES:
061252,000092:
061253,000093: 10,3620 03644 V1STO2S TC 1TO2SUB # ANSWER ARRIVES IN A AND MPAC.
061254,000094:
061255,000095: 10,3621 52162 DXCH MPAC +5
061256,000096: 10,3622 52155 DXCH MPAC
061257,000097: 10,3623 03644 TC 1TO2SUB
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Page 1398 |
061259,000099: 10,3624 54156 TS MPAC +2
061260,000100:
061261,000101: 10,3625 52160 DXCH MPAC +3
061262,000102: 10,3626 52155 DXCH MPAC
061263,000103: 10,3627 03644 TC 1TO2SUB
061264,000104: 10,3630 54155 TS MPAC +1
061265,000105:
061266,000106: 10,3631 30161 CA MPAC +5
061267,000107: 10,3632 54154 TS MPAC
061268,000108:
061269,000109: 10,3633 34753 TPMODE CAF ONE # MODE IS TP.
061270,000110: 10,3634 16060 TCF NEWMODE
061271,000111:
061272,000112: # V1STO2S FOR 2 COMPONENT VECTOR. USED BY RR.
061273,000113:
061274,000114: 10,3635 03644 2V1STO2S TC 1TO2SUB
061275,000115: 10,3636 52160 DXCH MPAC +3
061276,000116: 10,3637 52155 DXCH MPAC
061277,000117: 10,3640 03644 TC 1TO2SUB
061278,000118: 10,3641 54001 TS L
061279,000119: 10,3642 30157 CA MPAC +3
061280,000120: 10,3643 16055 TCF SLOAD2
061281,000121:
061282,000122: # SUBROUTINE TO DO DOUBLING AND 1'S TO 2'S CONVERSION:
061283,000123:
061284,000124: 10,3644 52155 1TO2SUB DXCH MPAC # FINAL MPAC +1 UNSPECIFIED.
061285,000125: 10,3645 20001 DDOUBL
061286,000126: 10,3646 10000 CCS A
061287,000127: 10,3647 64753 AD ONE
061288,000128: 10,3650 13652 TCF +2
061289,000129: 10,3651 40000 COM # THIS WAS REVERSE OF MSU.
061290,000130:
061291,000131: 10,3652 54154 TS MPAC # AND SKIP ON OVERFLOW.
061292,000132: 10,3653 00002 TC Q
061293,000133:
061294,000134: 10,3654 50000 INDEX A # OVERFLOW UNCORRECT AND IN MSU.
061295,000135: 10,3655 34734 CAF LIMITS
061296,000136: 10,3656 26154 ADS MPAC
061297,000137: 10,3657 00002 TC Q
061298,000138:
061299,000139: # THE FOLLOWING ROUTINE INCREMENTS IN 2S COMPLEMENT THE REGISTER WHOSE ADDRESS IS IN BUF BY THE 1S COMPL.
061300,000140: # QUANTITY FOUND IN TEM2. THIS MAY BE USED TO INCREMENT DESIRED IMU AND OPTICS CDU ANGLES OR ANY OTHER 2S COMPL.
061301,000141: # (+0 UNEQUAL TO -0) QUANTITY. MAY BE CALLED BY BANKCALL/SWCALL.
061302,000142:
061303,000143: 10,3660 54142 CDUINC TS TEM2 # 1S COMPL.QUANT. ARRIVES IN ACC. STORE IT
061304,000144: 10,3661 50130 INDEX BUF
061305,000145: 10,3662 10000 CCS 0 # CHANGE 2S COMPL. ANGLE(IN BUF)INTO 1S
061306,000146: 10,3663 64753 AD ONE
061307,000147: 10,3664 13670 TCF +4
061308,000148: 10,3665 64753 AD ONE
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Page 1399 |
061310,000150: 10,3666 64753 AD ONE # OVERFLOW HERE IF 2S COMPL. IS 180 DEG.
061311,000151: 10,3667 40000 COM
061312,000152:
061313,000153: 10,3670 60142 AD TEM2 # SULT MOVES FROM 2ND TO 3D QUAD. (OR BACK)
061314,000154: 10,3671 10000 CCS A # BACK TO 2S COMPL.
061315,000155: 10,3672 64753 AD ONE
061316,000156: 10,3673 13675 TCF +2
061317,000157: 10,3674 40000 COM
061318,000158: 10,3675 54142 TS TEM2 # STORE 14BIT QUANTITY WITH PRESENT SIGN
061319,000159: 10,3676 13702 TCF +4
061320,000160: 10,3677 50000 INDEX A # SIGN.
061321,000161: 10,3700 34734 CAF LIMITS # FIX IT, BY ADDING IN 37777 OR 40000
061322,000162: 10,3701 60142 AD TEM2
061323,000163:
061324,000164: 10,3702 50130 INDEX BUF
061325,000165: 10,3703 54000 TS 0 # STORE NEW ANGLE IN 2S COMPLEMENT.
061326,000166: 10,3704 00002 TC Q
061327,000167:
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Page 1400 |
061329,000169: # RTB TO TORQUE GYROS, EXCEPT FOR THE CALL TO IMUSTALL. ECADR OF COMMANDS ARRIVES IN X1.
061330,000170:
061331,000171: 10,3705 50120 PULSEIMU INDEX FIXLOC # ADDRESS OF GYRO COMMANDS SHOULD BE IN X1
061332,000172: 10,3706 30046 CA X1
061333,000173: 10,3707 04616 TC BANKCALL
061334,000174: 10,3710 17323 CADR IMUPULSE
061335,000175: 10,3711 16061 TCF DANZIG
061336,000176:
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Page 1401 |
061338,000178: # THE SUBROUTINE SIGNMPAC SETS C(MPAC, MPAC +1) TO SIGN(MPAC).
061339,000179: # FOR THIS, ONLY THE CONTENTS OF MPAC ARE EXAMINED. ALSO +0 YIELDS POSMAX AND -0 YIELDS NEGMAX.
061340,000180:
061341,000181: # ENTRY MAY BE BY EITHER OF THE FOLLOWING:
061342,000182: # 1. LIMIT THE SIZE OF MPAC ON INTERPRETIVE OVERFLOW:
061343,000183: # ENTRY: BOVB
061344,000184: # SIGNMPAC
061345,000185: # 2. GENERATE IN MPAC THE SIGNUM FUNCTION OF MPAC:
061346,000186: # ENTRY: RTB
061347,000187: # SIGNMPAC
061348,000188: # IN EITHER CASE, RETURN IS TO THE NEXT INTERPRETIVE INSTRUCTION IN THE CALLING SEQUENCE.
061349,000189:
061350,000190: 10,3712 00006 SIGNMPAC EXTEND
061351,000191: 10,3713 34733 DCA DPOSMAX
061352,000192: 10,3714 52155 DXCH MPAC
061353,000193: 10,3715 10000 CCS A
061354,000194: 10,3716 34755 DPMODE CAF ZERO # SETS MPAC +2 TO ZERO IN THE PROCESS
061355,000195: 10,3717 16057 TCF SLOAD2 +2
061356,000196: 10,3720 13721 TCF +1
061357,000197: 10,3721 00006 EXTEND
061358,000198: 10,3722 44733 DCS DPOSMAX
061359,000199: 10,3723 16055 TCF SLOAD2
061360,000200:
061361,000201: # RTB OP CODE NORMUNIT IS LIKE INTERPRETIVE INSTRUCTION UNIT, EXCEPT THAT IT CAN BE DEPENDED ON NOT TO BLOW
061362,000202: # UP WHEN THE VECTOR BEING UNITIZED IS VERY SMALL -- IT WILL BLOW UP WHEN ALL COMPONENTS ARE ZERO. IF NORMUNIT
061363,000203: # IS USED AND THE UPPER ORDER HALVES OF ALL COMPONENTS ARE ZERO, THE MAGNITUDE RETURNED IN 36D WILL BE TOO LARGE
061364,000204: # BY A FACTOR OF 2(13) AND THE SQUARED MAGNITUDE RETURNED AT 34D WILL BE TOO BIG BY A FACTOR OF 2(26).
061365,000205:
061366,000206: 10,3724 34753 NORMUNX1 CAF ONE
061367,000207: 10,3725 13727 TCF NORMUNIT +1
061368,000208: 10,3726 34755 NORMUNIT CAF ZERO
061369,000209: 10,3727 60120 AD FIXLOC
061370,000210: 10,3730 54156 TS MPAC +2
061371,000211: 10,3731 04616 TC BANKCALL # GET SIGN AGREEMENT IN ALL COMPONENTS
061372,000212: 10,3732 01010 CADR VECAGREE
061373,000213: 10,3733 10154 CCS MPAC
061374,000214: 10,3734 13770 TCF NOSHIFT
061375,000215: 10,3735 13737 TCF +2
061376,000216: 10,3736 13770 TCF NOSHIFT
061377,000217: 10,3737 10157 CCS MPAC +3
061378,000218: 10,3740 13770 TCF NOSHIFT
061379,000219: 10,3741 13743 TCF +2
061380,000220: 10,3742 13770 TCF NOSHIFT
061381,000221: 10,3743 10161 CCS MPAC +5
061382,000222: 10,3744 13770 TCF NOSHIFT
061383,000223: 10,3745 13747 TCF +2
061384,000224: 10,3746 13770 TCF NOSHIFT
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Page 1402 |
061386,000226: 10,3747 30155 CA MPAC +1 # SHIFT ALL COMPONENTS LEFT 13
061387,000227: 10,3750 00006 EXTEND
061388,000228: 10,3751 74736 MP BIT14
061389,000229: 10,3752 20155 DAS MPAC # DAS GAINS A LITTLE ACCURACY
061390,000230: 10,3753 30160 CA MPAC +4
061391,000231: 10,3754 00006 EXTEND
061392,000232: 10,3755 74736 MP BIT14
061393,000233: 10,3756 20160 DAS MPAC +3
061394,000234: 10,3757 30162 CA MPAC +6
061395,000235: 10,3760 00006 EXTEND
061396,000236: 10,3761 74736 MP BIT14
061397,000237: 10,3762 20162 DAS MPAC +5
061398,000238: 10,3763 34761 CAF THIRTEEN
061399,000239: 10,3764 50156 INDEX MPAC +2
061400,000240: 10,3765 54045 TS 37D
061401,000241: 10,3766 04635 OFFTUNIT TC POSTJUMP
061402,000242: 10,3767 01024 CADR UNIT +1 # SKIP THE "TC VECAGREE" DONE AT UNIT
061403,000243:
061404,000244: 10,3770 34755 NOSHIFT CAF ZERO
061405,000245: 10,3771 13764 TCF OFFTUNIT -2
061406,000246:
061407,000247: # RTB VECSGNAG ... FORCES SIGN AGREEMENT OF VECTOR IN MPAC.
061408,000248:
061409,000249: 10,3772 04616 VECSGNAG TC BANKCALL
061410,000250: 10,3773 01010 CADR VECAGREE
061411,000251: 10,3774 06061 TC DANZIG
061412,000252:
061413,000253:
End of include-file RTB_OP_CODES.agc. Parent file is MAIN.agc