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. |
028678,000002: ## Copyright: Public domain.
028679,000003: ## Filename: GROUND_TRACKING_DETERMINATION_PROGRAM_-_P21.agc
028680,000004: ## Purpose: Part of the reconstructed source code for LMY99 Rev 0,
028681,000005: ## otherwise known as Luminary Rev 99, the third release
028682,000006: ## of the Apollo Guidance Computer (AGC) software for Apollo 11.
028683,000007: ## It differs from LMY99 Rev 1 (the flown version) only in the
028684,000008: ## placement of a single label. The corrections shown here have
028685,000009: ## been verified to have the same bank checksums as AGC developer
028686,000010: ## Allan Klumpp's copy of Luminary Rev 99, and so are believed
028687,000011: ## to be accurate. This file is intended to be a faithful
028688,000012: ## recreation, except that the code format has been changed to
028689,000013: ## conform to the requirements of the yaYUL assembler rather than
028690,000014: ## the original YUL assembler.
028691,000015: ##
028692,000016: ## Assembler: yaYUL
028693,000017: ## Contact: Ron Burkey <info@sandroid.org>.
028694,000018: ## Website: www.ibiblio.org/apollo.
028695,000019: ## Pages: 654-657
028696,000020: ## Mod history: 2009-05-18 RSB Adapted from the corresponding
028697,000021: ## Luminary131 file, using page
028698,000022: ## images from Luminary 1A.
028699,000023: ## 2016-12-13 RSB GOTOP00H -> GOTOPOOH
028700,000024: ## 2016-12-14 RSB Proofed text comments with octopus/ProoferComments
028701,000025: ## but no errors found.
028702,000026: ## 2017-03-15 RSB Comment-text fixes identified in 5-way
028703,000027: ## side-by-side diff of Luminary 69/99/116/131/210.
028704,000028: ## 2017-08-01 MAS Created from LMY99 Rev 1.
028705,000029:
028706,000030: ## This source code has been transcribed or otherwise adapted from
028707,000031: ## digitized images of a hardcopy from the MIT Museum. The digitization
028708,000032: ## was performed by Paul Fjeld, and arranged for by Deborah Douglas of
028709,000033: ## the Museum. Many thanks to both. The images (with suitable reduction
028710,000034: ## in storage size and consequent reduction in image quality as well) are
028711,000035: ## available online at www.ibiblio.org/apollo. If for some reason you
028712,000036: ## find that the images are illegible, contact me at info@sandroid.org
028713,000037: ## about getting access to the (much) higher-quality images which Paul
028714,000038: ## actually created.
028715,000039: ##
028716,000040: ## The code has been modified to match LMY99 Revision 0, otherwise
028717,000041: ## known as Luminary Revision 99, the Apollo 11 software release preceeding
028718,000042: ## the listing from which it was transcribed. It has been verified to
028719,000043: ## contain the same bank checksums as AGC developer Allan Klumpp's listing
028720,000044: ## of Luminary Revision 99 (for which we do not have scans).
028721,000045: ##
028722,000046: ## Notations on Allan Klumpp's listing read, in part:
028723,000047: ##
028724,000048: ## ASSEMBLE REVISION 099 OF AGC PROGRAM LUMINARY BY NASA 2021112-51
028725,000049:
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Page 654 |
028727,000051: # GROUND TRACKING DETERMINATION PROGRAM P21
028728,000052: # PROGRAM DESCRIPTION
028729,000053: # MOD NO - 1
028730,000054: # MOD BY - N. M. NEVILLE
028731,000055:
028732,000056: # FUNCTIONAL DECRIPTION -
028733,000057: # TO PROVIDE THE ASTRONAUT DETAILS OF THE LM OR CSM GROUND TRACK WITHOUT
028734,000058: # THE NEED FOR GROUND COMMUNICATION (REQUESTED BY DSKY).
028735,000059:
028736,000060: # CALLING SEQUENCE -
028737,000061: # ASTRONAUT REQUEST THROUGH DSKY V37E21E
028738,000062:
028739,000063: # SUBROUTINES CALLED -
028740,000064: # GOPERF4
028741,000065: # GOFLASH
028742,000066: # THISPREC
028743,000067: # OTHPREC
028744,000068: # LAT-LONG
028745,000069:
028746,000070: # NORMAL EXIT MODES -
028747,000071: # ASTRONAUT REQUEST TROUGH DSKY TO TERMINATE PROGRAM V34E
028748,000072:
028749,000073: # ALARM OR ABORT EXIT MODES -
028750,000074: # NONE
028751,000075:
028752,000076: # OUTPUT -
028753,000077: # OCTAL DISPLAY OF OPTION CODE AND VEHICLE WHOSE GROUND TRACK IS TO BE
028754,000078: # COMPUTED
028755,000079: # OPTION CODE 00002
028756,000080: # THIS 00001
028757,000081: # OTHER 00002
028758,000082: # DECIMAL DISPLAY OF TIME TO BE INTEGRATED TO HOURS, MINUTES, SECONDS
028759,000083: # DECIMAL DISPLAY OF LAT,LONG,ALT
028760,000084:
028761,000085: # ERASABLE INITIALIZATION REQUIRED
028762,000086: # AX0 2DEC 4.652459653 E-5 RADIANS %68-69 CONSTANTS"
028763,000087: # -AY0 2DEC 2.147535898 E-5 RADIANS
028764,000088: # AZ0 2DEC .7753206164 REVOLUTIONS
028765,000089: # FOR LUNAR ORBITS 504LM VECTOR IS NEEDED
028766,000090: # 504LM 2DEC -2.700340600 E-5 RADIANS
028767,000091: # 504LM _2 2DEC -7.514128400 E-4 RADIANS
028768,000092: # 504LM _4 2DEC _2.553198641 E-4 RADIANS
028769,000093:
028770,000094: # NONE
028771,000095:
028772,000096: # DEBRIS
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Page 655 |
028774,000098: # CENTRALS - A,Q,L
028775,000099: # OTHER - THOSE USED BY THE ABOVE LISTED SUBROUTINES
028776,000100: # SEE LEMPREC, LAT-LONG
028777,000101:
028778,000102: 35,2545 30,2000 SBANK= LOWSUPER # FOR LOW 2CADR'S.
028779,000103:
028780,000104: 33,2200 BANK 33
028781,000105: 24,2000 SETLOC P20S
028782,000106: 24,2000 BANK
028783,000107:
028784,000108: 24,3505 E7,1762 EBANK= P21TIME
028785,000109: 24,3505 COUNT* $$/P21
028786,000110: 24,3505 34753 PROG21 CAF ONE
028787,000111: 24,3506 55145 TS OPTION2 # ASSUMED VEHICLE IS LM, R2 = 00001
028788,000112: 24,3507 34752 CAF BIT2 # OPTION 2
028789,000113: 24,3510 04616 TC BANKCALL
028790,000114: 24,3511 20633 CADR GOPERF4
028791,000115: 24,3512 06001 TC GOTOPOOH # TERMINATE
028792,000116: 24,3513 03515 TC +2 # PROCEED VALUE OF ASSUMED VEHICLE OK
028793,000117: 24,3514 03507 TC -5 # R2 LOADED THROUGH DSKY
028794,000118: 24,3515 33665 P21PROG1 CAF V6N34 # LOAD DESIRED TIME OF LAT-LONG.
028795,000119: 24,3516 04616 TC BANKCALL
028796,000120: 24,3517 20476 CADR GOFLASH
028797,000121: 24,3520 06001 TC GOTOPOOH # TERM
028798,000122: 24,3521 03523 TC +2 # PROCEED VALUES OK
028799,000123: 24,3522 03515 TC -5 # TIME LOADED THROUGH DSKY
028800,000124: 24,3523 06037 TC INTPRET
028801,000125: 24,3524 77745 DLOAD
028802,000126: 24,3525 01046 DSPTEM1
028803,000127: 24,3526 34041 STCALL TDEC1 # INTEGRATE TO TIME SPECIFIED IN TDEC
028804,000128: 24,3527 27414 INTSTALL
028805,000129: 24,3530 43014 BON CLEAR
028806,000130: 24,3531 00304 P21FLAG
028807,000131: 24,3532 51550 P21CONT # ON --- RECYCLE USING BASE VECTOR
028808,000132: 24,3533 01674 VINTFLAG # OFF -- 1ST PASS CALL BASE VECTOR
028809,000133: 24,3534 70535 SLOAD SR1
028810,000134: 24,3535 01146 OPTION2
028811,000135: 24,3536 43030 BHIZ SET
028812,000136: 24,3537 51541 +2 # ZERO -- THIS VEHICLE (LM)
028813,000137: 24,3540 01474 VINTFLAG # ONE -- OTHER VEHICLE (CM)
028814,000138: 24,3541 43014 CLEAR CLEAR
028815,000139: 24,3542 01676 DIM0FLAG
028816,000140: 24,3543 01673 INTYPFLG # PRECISION
028817,000141: 24,3544 77624 CALL
028818,000142: 24,3545 27134 INTEGRV # CALCULATE
028819,000143: 24,3546 77650 GOTO # -AND
028820,000144: 24,3547 51571 P21VSAVE # -SAVE BASE VECTOR
028821,000145: 24,3550 77775 P21CONT VLOAD
028822,000146: 24,3551 03676 P21BASER # RECYCLE -- INTEG FROM BASE VECTOR
028823,000147: 24,3552 25535 STOVL RCV # --POS
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Page 656 |
028825,000149: 24,3553 03704 P21BASEV
028826,000150: 24,3554 15543 STODL VCV # --VEL
028827,000151: 24,3555 03763 P21TIME
028828,000152: 24,3556 01517 STORE TET # --TIME
028829,000153: 24,3557 43014 CLEAR CLEAR
028830,000154: 24,3560 01676 DIM0FLAG
028831,000155: 24,3561 00263 MOONFLAG
028832,000156: 24,3562 53135 SLOAD BZE
028833,000157: 24,3563 01164 P21ORIG
028834,000158: 24,3564 51567 +3 # ZERO = EARTH
028835,000159: 24,3565 77614 SET # ---2 = MOON
028836,000160: 24,3566 00063 MOONFLAG
028837,000161: 24,3567 77624 +3 CALL
028838,000162: 24,3570 27107 INTEGRVS
028839,000163: 24,3571 77745 P21VSAVE DLOAD # SAVE CURRENT BASE VECTOR
028840,000164: 24,3572 00015 TAT
028841,000165: 24,3573 27763 STOVL P21TIME # --TIME
028842,000166: 24,3574 00017 RATT1
028843,000167: 24,3575 27676 STOVL P21BASER # --POS B-29 OR B-27
028844,000168: 24,3576 00025 VATT1
028845,000169: 24,3577 03704 STORE P21BASEV # --VEL B-07 OR B-05
028846,000170: 24,3600 53646 ABVAL SL*
028847,000171: 24,3601 57576 0,2
028848,000172: 24,3602 27712 STOVL P21VEL # VEL/ FOR N91 DISP
028849,000173: 24,3603 00001 RATT
028850,000174: 24,3604 50256 UNIT DOT
028851,000175: 24,3605 00007 VATT # U(R).V
028852,000176: 24,3606 67471 DDV ASIN # U(R).U(V)
028853,000177: 24,3607 03712 P21VEL
028854,000178: 24,3610 03714 STORE P21GAM # SIN-1 U(R).U(V) , -90 TO &90
028855,000179: 24,3611 67334 SXA,2 SLOAD
028856,000180: 24,3612 01163 P21ORIG # 0 = EARTH
028857,000181: 24,3613 01146 OPTION2
028858,000182: 24,3614 46142 SR1 BHIZ
028859,000183: 24,3615 51620 +3
028860,000184: 24,3616 77650 GOTO
028861,000185: 24,3617 51623 +4
028862,000186: 24,3620 77614 +3 BON
028863,000187: 24,3621 04307 SURFFLAG
028864,000188: 24,3622 51625 P21DSP
028865,000189: 24,3623 77614 +4 SET
028866,000190: 24,3624 00064 P21FLAG
028867,000191: 24,3625 67214 P21DSP CLEAR SLOAD # GENERATE DISPLAY DATA
028868,000192: 24,3626 01663 LUNAFLAG
028869,000193: 24,3627 00050 X2
028870,000194: 24,3630 43054 BZE SET
028871,000195: 24,3631 51633 +2 # 0 = EARTH
028872,000196: 24,3632 01463 LUNAFLAG
028873,000197: 24,3633 77775 VLOAD
028874,000198: 24,3634 00001 RATT
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Page 657 |
028876,000200: 24,3635 16032 STODL ALPHAV
028877,000201: 24,3636 00015 TAT
028878,000202: 24,3637 45014 CLEAR CALL
028879,000203: 24,3640 00662 ERADFLAG
028880,000204: 24,3641 26351 LAT-LONG
028881,000205: 24,3642 77605 DMP # MPAC = ALT, METERS B-29
028882,000206: 24,3643 11667 K.01
028883,000207: 24,3644 03716 STORE P21ALT # ALT/100 FOR N91 DISP
028884,000208: 24,3645 77776 EXIT
028885,000209: 24,3646 33664 CAF V06N43 # DISPLAY LAT, LONG, ALT
028886,000210: 24,3647 04616 TC BANKCALL # LAT, LONG = 1/2 REVS B0
028887,000211: 24,3650 20476 CADR GOFLASH # ALT = KM B14
028888,000212: 24,3651 06001 TC GOTOPOOH # TERM
028889,000213: 24,3652 06001 TC GOTOPOOH
028890,000214: 24,3653 06037 TC INTPRET # V32E RECYCLE
028891,000215: 24,3654 43345 DLOAD DAD
028892,000216: 24,3655 03763 P21TIME
028893,000217: 24,3656 11663 600SEC # 600 SECONDS OR 10 MIN
028894,000218: 24,3657 01046 STORE DSPTEM1
028895,000219: 24,3660 77634 RTB
028896,000220: 24,3661 51515 P21PROG1
028897,000221: 24,3662 00003 25140 600SEC 2DEC 60000 B-28 # 10 MIN
028898,000222:
028899,000223: 24,3664 01453 V06N43 VN 00643
028900,000224: 24,3665 01442 V6N34 VN 00634
028901,000225: 24,3666 00243 32703 K.01 2DEC .01
028902,000226:
End of include-file GROUND_TRACKING_DETERMINATION_PROGRAM_-_P21.agc. Parent file is MAIN.agc