Source Code
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These source-code files were obtained by digitally photographing
an Artemis 72 (Apollo 15-17 Command Module) program listing from a private
collection and then
modifying pre-existing Comanche 55 (Apollo 11) source files to
incorporate changes. Photography was by Ron Burkey, and transcription
was performed by a team of volunteers. Note that the page images
presented online are of reduced quality, and that additional images
may be available. Report any conversion errors or legibility
problems in page images to info@sandroid.org.
Notations on the program listing read, in part:GAP: ASSEMBLE REVISION 072 OF AGC PROGRAM ARTEMIS BY NASA 2021114-011 11:40 FEB. 26, 1971Note that the date is the date of the printout, not the date of the program revision. |
058457,000002: ## Copyright: Public domain.
058458,000003: ## Filename: POWERED_FLIGHT_SUBROUTINES.agc
058459,000004: ## Purpose: Part of the source code for Artemis (i.e., Colossus 3),
058460,000005: ## build 072. This is for the Command Module's (CM)
058461,000006: ## Apollo Guidance Computer (AGC), for
058462,000007: ## Apollo 15-17.
058463,000008: ## Assembler: yaYUL
058464,000009: ## Contact: Jim Lawton <jim DOT lawton AT gmail DOT com>
058465,000010: ## Website: www.ibiblio.org/apollo/index.html
058466,000011: ## Page Scans: www.ibiblio.org/apollo/ScansForConversion/Artemis072/
058467,000012: ## Mod history: 2009-08-21 JL Adapted from corresponding Comanche 055 file.
058468,000013: ## 2010-02-20 RSB Un-##'d this header.
058469,000014: ## 2017-02-08 RSB Proofed comment text by diff'ing vs Comanche 55.
058470,000015:
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Page 1364 |
058472,000017:
058473,000018: 23,2000 SETLOC POWFLITE
058474,000019: 23,2000 BANK
058475,000020:
058476,000021: 23,3530 0142 EBANK= DEXDEX
058477,000022: 23,3530 COUNT* $$/POWFL
058478,000023:
058479,000024: # CDUTRIG, CDUTRIG1, CDUTRIG2, AND CD*TR*GS ALL COMPUTE THE SINES AND
058480,000025: # COSINES OF THREE 2'S COMPLEMENT ANGLES AND PLACE THE RESULT, DOUBLE
058481,000026: # PRECISION, IN THE SAME ORDER AS THE INPUTS, AT SINCDU AND COSCDU. AN
058482,000027: # ADDITIONAL OUTPUT IS THE 1'S COMPLEMENT ANGLES AT CDUSPOT. THESE
058483,000028: # ROUTINES GO OUT OF THEIR WAY TO LEAVE THE MPAC AREA AS THEY FIND IT,
058484,000029: # EXCEPT FOR THE GENERALLY UNIMPORTANT MPAC +2. THEY DIFFER ONLY IN
058485,000030: # WHERE THEY GET THE ANGLES, AND IN METHOD OF CALLING.
058486,000031:
058487,000032: # CDUTRIG (AND CDUTRIG1, WHICH CAN BE CALLED IN BASIC) COMPUTE THE
058488,000033: # SINES AND COSINES FROM THE CURRENT CONTENTS OF THE CDU REGISTERS.
058489,000034: # THE CONTENTS OF CDUTEMP, ETC., ARE NOT TOUCHED SO THAT THEY MAY
058490,000035: # CONTINUE TO FORM A CONSISTENT SET WITH THE LATEST PIPA READINGS.
058491,000036:
058492,000037: # CDUTRIG1 IS LIKE CDUTRIG EXCEPT THAT IT CAN BE CALLED IN BASIC.
058493,000038:
058494,000039: # CD*TR*GS FINDS CDU VALUES IN CDUSPOT RATHER THAN IN CDUTEMP. THIS
058495,000040: # ALLOWS USERS TO MAKE TRANSFORMATIONS USING ARBITRARY ANGLES, OR REAL
058496,000041: # ANGLES IN AN ORDER OTHER THAN X Y Z. A CALL TO THIS ROUTINE IS
058497,000042: # NECESSARY IN PREPARATION FOR A CALL TO AX*SR*T IN EITHER OF ITS TWO
058498,000043: # MODES (SMNB OR NBSM). SINCE AX*SR*T EXPECTS TO FIND THE SINES AND
058499,000044: # COSINES IN THE ORDER Y Z X THE ANGLES MUST HAVE BEEN PLACED IN CDUSPOT
058500,000045: # IN THIS ORDER. CD*TR*GS NEED NOT BE REPEATED WHEN AX*SR*T IS CALLED
058501,000046: # MORE THAN ONCE, PROVIDED THE ANGLES HAVE NOT CHANGED. NOTE THAT SINCE
058502,000047: # IT CLOBBERS BUF2 (IN THE SINE AND COSINE ROUTINES) CD*TR*GS CANNOT BE
058503,000048: # CALLED USING BANKCALL. SORRY.
058504,000049:
058505,000050: # CD*TR*G IS LIKE CD*TR*GS EXCEPT THAT IT CAN BE CALLED IN
058506,000051: # INTERPRETIVE.
058507,000052:
058508,000053: 23,3530 77776 CDUTRIG EXIT
058509,000054: 23,3531 03534 TC CDUTRIGS
058510,000055: 23,3532 06006 TC INTPRET
058511,000056: 23,3533 77616 RVQ
058512,000057:
058513,000058: 23,3534 30032 CDUTRIGS CA CDUX
058514,000059: 23,3535 55175 TS CDUSPOT +4
058515,000060: 23,3536 30033 CA CDUY
058516,000061: 23,3537 55171 TS CDUSPOT
058517,000062: 23,3540 30034 CA CDUZ
058518,000063: 23,3541 55173 TS CDUSPOT +2
058519,000064:
058520,000065: 23,3542 00006 CD*TR*GS EXTEND
058521,000066: 23,3543 22142 QXCH TEM2
058522,000067: 23,3544 34766 CAF FOUR
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Page 1365 |
058524,000069: 23,3545 76211 TR*GL**P MASK SIX # MAKE IT EVEN AND SMALLER
058525,000070: 23,3546 54143 TS TEM3
058526,000071: 23,3547 50143 INDEX TEM3
058527,000072: 23,3550 31171 CA CDUSPOT
058528,000073: 23,3551 52155 DXCH MPAC # STORING 2'S COMP ANGLE, LOADING MPAC
058529,000074: 23,3552 52127 DXCH VBUF +4 # STORING MPAC FOR LATER RESTORATION
058530,000075: 23,3553 04733 TC USPRCADR
058531,000076: 23,3554 51754 CADR CDULOGIC
058532,000077: 23,3555 00006 EXTEND
058533,000078: 23,3556 30155 DCA MPAC
058534,000079: 23,3557 50143 INDEX TEM3
058535,000080: 23,3560 53172 DXCH CDUSPOT # STORING 1'S COMPLEMENT ANGLE
058536,000081: 23,3561 04733 TC USPRCADR
058537,000082: 23,3562 01514 CADR COSINE
058538,000083: 23,3563 52155 DXCH MPAC
058539,000084: 23,3564 50143 INDEX TEM3
058540,000085: 23,3565 53150 DXCH COSCDU # STORING COSINE
058541,000086: 23,3566 00006 EXTEND
058542,000087: 23,3567 50143 INDEX TEM3
058543,000088: 23,3570 31172 DCA CDUSPOT # LOADING 1'S COMPLEMENT ANGLE
058544,000089: 23,3571 04733 TC USPRCADR
058545,000090: 23,3572 01526 CADR SINE +1 # SINE +1 EXPECTS ARGUMENT IN A AND L
058546,000091: 23,3573 52127 DXCH VBUF +4 # BRINGING UP PRIOR MPAC TO BE RESTORED
058547,000092: 23,3574 52155 DXCH MPAC
058548,000093: 23,3575 50143 INDEX TEM3
058549,000094: 23,3576 53142 DXCH SINCDU
058550,000095: 23,3577 10143 CCS TEM3
058551,000096: 23,3600 13545 TCF TR*GL**P
058552,000097: 23,3601 00142 TC TEM2
058553,000098:
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Page 1366 |
058555,000100:
058556,000101: # ****************************************************************************************************************
058557,000102:
058558,000103: # QUICTRIG, INTENDED FOR GUIDANCE CYCLE USE WHERE TIME IS CRITICAL, IS A MUCH FASTER VERSION OF CD*TR*GS.
058559,000104: # QUICTRIG COMPUTES AND STORES THE SINES AND COSINES OF THE 2'S COMPLEMENT ANGLES AT CDUSPOT, CDUSPOT +2,
058560,000105: # AND CDUSPOT +4. UNLIKE CD*TR*GS, QUICTRIG DOES NOT LEAVE THE 1'S COMPLEMENT VERSIONS OF THE ANGLES IN
058561,000106: # CDUSPOT. QUICTRIG'S EXECUTION TIME IS 4.1 MS; THIS IS 10 TIMES AS FAST AS CD*TR*GS. QUICTRIG MAY BE
058562,000107: # CALLED FROM INTERPRETIVE AS AN RTB OP-CODE, OR FROM BASIC VIA BANKCALL OR IBNKCALL.
058563,000108:
058564,000109: 23,3602 00004 QUICTRIG INHINT # INHINT SINCE DAP USES THE SAME TEMPS
058565,000110: 23,3603 00006 EXTEND
058566,000111: 23,3604 22061 QXCH ITEMP1
058567,000112: 23,3605 34766 CAF FOUR
058568,000113: 23,3606 76211 +4 MASK SIX
058569,000114: 23,3607 54062 TS ITEMP2
058570,000115: 23,3610 50062 INDEX ITEMP2
058571,000116: 23,3611 31171 CA CDUSPOT
058572,000117: 23,3612 05061 TC SPSIN
058573,000118: 23,3613 00006 EXTEND
058574,000119: 23,3614 74753 MP BIT14 # SCALE DOWN TO MATCH INTERPRETER OUTPUTS
058575,000120: 23,3615 50062 INDEX ITEMP2
058576,000121: 23,3616 53142 DXCH SINCDU
058577,000122: 23,3617 50062 INDEX ITEMP2
058578,000123: 23,3620 31171 CA CDUSPOT
058579,000124: 23,3621 05060 TC SPCOS
058580,000125: 23,3622 00006 EXTEND
058581,000126: 23,3623 74753 MP BIT14
058582,000127: 23,3624 50062 INDEX ITEMP2
058583,000128: 23,3625 53150 DXCH COSCDU
058584,000129: 23,3626 10062 CCS ITEMP2
058585,000130: 23,3627 13606 TCF QUICTRIG +4
058586,000131: 23,3630 30061 CA ITEMP1
058587,000132: 23,3631 00003 RELINT
058588,000133: 23,3632 00000 TC A
058589,000134:
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Page 1367 |
058591,000136:
058592,000137: # ****************************************************************************************************************
058593,000138:
058594,000139: # THESE INTERFACE ROUTINES MAKE IT POSSIBLE TO CALL AX*SR*T, ETC., IN
058595,000140: # INTERPRETIVE. LATER, WHERE POSSIBLE, THEY WILL BE ELIMINATED.
058596,000141:
058597,000142: # THESE INTERFACE ROUTINES ARE PERMANENT. ALL RESTORE USER'S EBANK
058598,000143: # SETTING. ALL ARE STRICT INTERPRETIVE SUBROUTINES, CALLED USING "CALL",
058599,000144: # RETURNING VIA QPRET. ALL EXPECT AND RETURN THE VECTOR TO BE TRANSFOR-
058600,000145: # MED INTERPRETER-STYLE IN MPAC; COMPONENTS AT MPAC, MPAC +3, AND MPAC +5.
058601,000146:
058602,000147: # TRG*SMNB AND TRG*NBSM BOTH EXPECT TO SEE THE 2'S COMPLEMENT ANGLES
058603,000148: # AT CDUSPOT (ORDER Y Z X, AT CDUSPOT, CDUSPOT +2, AND CDUSPOT +4; ODD
058604,000149: # LOCATIONS NEED NOT BE ZEROED). TRG*NBSM DOES THE NB TO SM TRANSFOR-
058605,000150: # MATION; TRG*SMNB, VICE VERSA.
058606,000151:
058607,000152: # CDU*NBSM DOES ITS TRANSFORMATION USING THE PRESENT CONTENTS OF
058608,000153: # THE CDU COUNTERS. OTHERWISE IT IS LIKE TRG*NBSM.
058609,000154:
058610,000155: # CDU*SMNB IS THE COMPLEMENT OF CDU*NBSM.
058611,000156:
058612,000157: 23,3633 77776 *SMNB* EXIT
058613,000158: 23,3634 07466 C*MM*N1 TC MPACVBUF # AX*SR*T EXPECTS VECTOR IN VBUF
058614,000159: 23,3635 46214 CS THREE # SIGNAL FOR SM TO NB TRANSFORMATION
058615,000160: 23,3636 03651 C*MM*N2 TC AX*SR*T
058616,000161: 23,3637 06006 TC INTPRET
058617,000162: 23,3640 43575 VLOAD RVQ
058618,000163: 23,3641 00123 VBUF
058619,000164:
058620,000165: 23,3642 77776 TRG*NBSM EXIT
058621,000166: 23,3643 03542 TC CD*TR*GS
058622,000167: 23,3644 07466 C*MM*N3 TC MPACVBUF # FOR AX*SR*T
058623,000168: 23,3645 36214 CA THREE # SIGNAL FOR NB TO SM TRANSFORMATION
058624,000169: 23,3646 13636 TCF C*MM*N2
058625,000170:
058626,000171: # *NBSM* AND *SMNB* EXPECT TO SEE THE SINES AND COSINES (AT SINCDU
058627,000172: # AND COSCDU) RATHER THAN THE ANGLES THEMSELVES. OTHERWISE THEY ARE
058628,000173: # LIKE TRG*NBSM AND TRG*SMNB.
058629,000174:
058630,000175: # NOTE THAT JUST AS CD*TR*GS NEED BE CALLED ONLY ONCE FOR EACH SERIES
058631,000176: # OF TRANSFORMATIONS USING THE SAME ANGLES, SO TOO ONLY ONE OF TRG*NBSM
058632,000177: # AND TRG*SMNB NEED BE CALLED FOR EACH SERIES. FOR SUBSEQUENT TRANSFOR-
058633,000178: # MATIONS USE *NBSM* AND *SMNB*.
058634,000179:
058635,000180: 23,3647 77776 *NBSM* EXIT
058636,000181: 23,3650 13644 TCF C*MM*N3
058637,000182:
058638,000183: # AX*SR*T COMBINES THE OLD SMNB AND NBSM. FOR THE NB TO SM
058639,000184: # TRANSFORMATION, ENTER WITH +3 IN A. FOR SM TO NB, ENTER WITH -3.
058640,000185: # THE VECTOR TO BE TRANSFORMED ARRIVES, AND IS RETURNED, IN VBUF.
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Page 1368 |
058642,000187: # AX*SR*T EXPECTS TO FIND THE SINES AND COSINES OF THE ANGLES OF ROTATION
058643,000188: # AT SINCDU AND COSCDU, IN THE ORDER Y Z X. A CALL TO CD*TR*GS, WITH
058644,000189: # THE 2'S COMPLEMENT ANGLES (ORDER Y Z X) AT CDUSPOT, WILL TAKE CARE OF
058645,000190: # THIS. HERE IS A SAMPLE CALLING SEQUENCE:-
058646,000191:
058647,000192: # TC CDUTRIGS
058648,000193: # CS THREE ("CA THREE" FOR NBSM)
058649,000194: # TC AX*SR*T
058650,000195:
058651,000196: # THE CALL TO CD*TR*GS NEED NOT BE REPEATED, WHEN AX*SR*T IS CALLED MORE
058652,000197: # THAN ONCE, UNLESS THE ANGLES HAVE CHANGED.
058653,000198:
058654,000199: # AX*SR*T IS GUARANTEED SAFE ONLY FOR VECTORS OF MAGNITUDE LESS THAN
058655,000200: # UNITY. A LOOK AT THE CASE IN WHICH A VECTOR OF GREATER MAGNITUDE
058656,000201: # HAPPENS TO LIE ALONG AN AXIS OF THE SYSTEM TO WHICH IT IS TO BE TRANS-
058657,000202: # FORMED CONVINCES ONE THAT THIS IS A RESTRICTION WHICH MUST BE ACCEPTED.
058658,000203:
058659,000204: 23,3651 54142 AX*SR*T TS DEXDEX # WHERE IT BECOMES THE INDEX OF INDEXES
058660,000205: 23,3652 00006 EXTEND
058661,000206: 23,3653 22145 QXCH RTNSAVER
058662,000207:
058663,000208: 23,3654 10142 R*TL**P CCS DEXDEX # +3 --> 0 -3 --> 2
058664,000209: 23,3655 40142 CS DEXDEX # THUS: +2 --> 1 -2 --> 1
058665,000210: 23,3656 66214 AD THREE # +1 --> 2 -1 --> 0
058666,000211: 23,3657 00006 EXTEND
058667,000212: 23,3660 50000 INDEX A
058668,000213: 23,3661 33740 DCA INDEXI
058669,000214: 23,3662 52144 DXCH DEXI
058670,000215:
058671,000216: 23,3663 34770 CA ONE
058672,000217: 23,3664 54130 TS BUF
058673,000218: 23,3665 00006 EXTEND
058674,000219: 23,3666 50143 INDEX DEX1
058675,000220: 23,3667 40123 DCS VBUF
058676,000221: 23,3670 13672 TCF LOOP1 # REALLY BE A SUBTRACT, AND VICE VERSA
058677,000222:
058678,000223: 23,3671 52131 LOOP2 DXCH BUF # LOADING VECTOR COMPONENT, STORING INDEX
058679,000224:
058680,000225: 23,3672 52155 LOOP1 DXCH MPAC
058681,000226: 23,3673 33736 CA SINESLOC
058682,000227: 23,3674 60143 AD DEX1
058683,000228: 23,3675 54116 TS ADDRWD
058684,000229:
058685,000230: 23,3676 07056 TC DMPSUB # MULTIPLY BY SIN(CDUANGLE)
058686,000231: 23,3677 10142 CCS DEXDEX
058687,000232: 23,3700 52155 DXCH MPAC # NBSM CASE
058688,000233: 23,3701 13704 TCF +3
058689,000234: 23,3702 00006 EXTEND # SMNB CASE
058690,000235: 23,3703 40155 DCS MPAC
058691,000236: 23,3704 52134 DXCH TERM1TMP
058692,000237:
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Page 1369 |
058694,000239: 23,3705 36211 CA SIX # SINCDU AND COSCDU (EACH 6 WORDS) MUST
058695,000240: 23,3706 26116 ADS ADDRWD # BE CONSECUTIVE AND IN THAT ORDER
058696,000241:
058697,000242: 23,3707 00006 EXTEND
058698,000243: 23,3710 50130 INDEX BUF
058699,000244: 23,3711 50143 INDEX DEX1
058700,000245: 23,3712 30123 DCA VBUF
058701,000246: 23,3713 52155 DXCH MPAC
058702,000247: 23,3714 07056 TC DMPSUB # MULTIPLY BY COS(CDUANGLE)
058703,000248: 23,3715 52155 DXCH MPAC
058704,000249: 23,3716 20134 DAS TERM1TMP
058705,000250: 23,3717 52134 DXCH TERM1TMP
058706,000251: 23,3720 20001 DDOUBL
058707,000252: 23,3721 50130 INDEX BUF
058708,000253: 23,3722 50143 INDEX DEX1
058709,000254: 23,3723 52123 DXCH VBUF
058710,000255: 23,3724 52131 DXCH BUF # LOADING INDEX, STORING VECTOR COMPONENT
058711,000256:
058712,000257: 23,3725 10000 CCS A # 'CAUSE THAT'S WHERE THE INDEX NOW IS
058713,000258: 23,3726 13671 TCF LOOP2
058714,000259:
058715,000260: 23,3727 00006 EXTEND
058716,000261: 23,3730 26142 DIM DEXDEX # DECREMENT MAGNITUDE PRESERVING SIGN
058717,000262:
058718,000263: 23,3731 10142 TSTPOINT CCS DEXDEX # ONLY THE BRANCHING FUNCTION IS USED
058719,000264: 23,3732 13654 TCF R*TL**P
058720,000265: 23,3733 00145 TC RTNSAVER
058721,000266: 23,3734 13654 TCF R*TL**P
058722,000267: 23,3735 00145 TC RTNSAVER
058723,000268:
058724,000269: 23,3736 01141 SINESLOC ADRES SINCDU # FOR USE IN SETTING ADDRWD
058725,000270:
058726,000271: 23,3737 00004 INDEXI DEC 4 B-14 # ********** DON'T **********
058727,000272: 23,3740 00002 DEC 2 B-14 # ********** TOUCH **********
058728,000273: 23,3741 00000 DEC 0 B-14 # ********** THESE **********
058729,000274: 23,3742 00004 DEC 4 B-14 # ********** CONSTANTS **********
058730,000275:
058731,000276: # ****************************************************************************************************************
058732,000277:
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Page 1370 |
058734,000279:
058735,000280: # THIS SUBROUTINE COMPUTES INCREMENTAL CHANGES IN CDU(GIMBAL) ANGLES FROM INCREMENTAL CHANGES ABOUT SM AXES. IT
058736,000281: # REQUIRES SM INCREMENTS AS A DP VECTOR SCALED AT ONE REVOLUTION(DTHETASM,+2,+4). SIN,COS(CDUY,Z,X) ARE IN
058737,000282: # SINCDU,+2,+4 AND COSCDU,+2,+4 RESPECTIVELY, SCALED TO ONE HALF. CDU INCREENTS ARE PLACED IN DCDU,+2,+4 SCALED TO
058738,000283: # ONE REVOLUTION.
058739,000284:
058740,000285: # * COS(IGA)SEC(MGA) 0 -SIN(IGA)SEC(MGA) *
058741,000286: # * *
058742,000287: # * -COS(IGA)TAN(MGA) 1 SIN(IGA)TAN(MGA) *
058743,000288: # * *
058744,000289: # * SIN(IGA) 0 COS(IGA) *
058745,000290:
058746,000291: 23,2000 SETLOC POWFLIT1
058747,000292: 23,2000 BANK
058748,000293: 23,3743 COUNT* $$/POWFL
058749,000294: 23,3743 41345 SMCDURES DLOAD DMP
058750,000295: 23,3744 03212 DTHETASM
058751,000296: 23,3745 01150 COSCDUY
058752,000297:
058753,000298: 23,3746 41325 PDDL DMP
058754,000299: 23,3747 03216 DTHETASM +4
058755,000300: 23,3750 01142 SINCDUY
058756,000301:
058757,000302: 23,3751 77621 BDSU
058758,000303: 23,3752 77671 DDV
058759,000304: 23,3753 01152 COSCDUZ
058760,000305: 23,3754 03204 STORE DCDU
058761,000306:
058762,000307: 23,3755 72405 DMP SL1 # SCALE
058763,000308: 23,3756 01144 SINCDUZ
058764,000309: 23,3757 77621 BDSU
058765,000310:
058766,000311: 23,3760 03214 DTHETASM +2
058767,000312: 23,3761 17206 STODL DCDU +2
058768,000313: 23,3762 03212 DTHETASM
058769,000314:
058770,000315: 23,3763 65205 DMP PDDL
058771,000316: 23,3764 01142 SINCDUY
058772,000317: 23,3765 03216 DTHETASM +4
058773,000318:
058774,000319: 23,3766 43205 DMP DAD
058775,000320: 23,3767 01150 COSCDUY
058776,000321: 23,3770 77752 SL1
058777,000322: 23,3771 03210 STORE DCDU +4
058778,000323: 23,3772 77616 RVQ
End of include-file POWERED_FLIGHT_SUBROUTINES.agc. Parent file is MAIN.agc