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. |
028492,000002: ## Copyright: Public domain.
028493,000003: ## Filename: LAMBERT_AIMPOINT_GUIDANCE.agc
028494,000004: ## Purpose: Part of the reconstructed source code for LMY99 Rev 0,
028495,000005: ## otherwise known as Luminary Rev 99, the third release
028496,000006: ## of the Apollo Guidance Computer (AGC) software for Apollo 11.
028497,000007: ## It differs from LMY99 Rev 1 (the flown version) only in the
028498,000008: ## placement of a single label. The corrections shown here have
028499,000009: ## been verified to have the same bank checksums as AGC developer
028500,000010: ## Allan Klumpp's copy of Luminary Rev 99, and so are believed
028501,000011: ## to be accurate. This file is intended to be a faithful
028502,000012: ## recreation, except that the code format has been changed to
028503,000013: ## conform to the requirements of the yaYUL assembler rather than
028504,000014: ## the original YUL assembler.
028505,000015: ##
028506,000016: ## Assembler: yaYUL
028507,000017: ## Contact: Ron Burkey <info@sandroid.org>.
028508,000018: ## Website: www.ibiblio.org/apollo.
028509,000019: ## Pages: 651-653
028510,000020: ## Mod history: 2009-05-18 RSB Transcribed from Luminary 099
028511,000021: ## page images.
028512,000022: ## 2009-06-05 RSB Corrected 4 typos.
028513,000023: ## 2009-06-07 RSB Fixed a typo.
028514,000024: ## 2016-12-14 RSB VNP00H -> VNPOOH.
028515,000025: ## 2016-12-14 RSB Proofed text comments with octopus/ProoferComments
028516,000026: ## and corrected the errors found.
028517,000027: ## 2017-08-01 MAS Created from LMY99 Rev 1.
028518,000028:
028519,000029: ## This source code has been transcribed or otherwise adapted from
028520,000030: ## digitized images of a hardcopy from the MIT Museum. The digitization
028521,000031: ## was performed by Paul Fjeld, and arranged for by Deborah Douglas of
028522,000032: ## the Museum. Many thanks to both. The images (with suitable reduction
028523,000033: ## in storage size and consequent reduction in image quality as well) are
028524,000034: ## available online at www.ibiblio.org/apollo. If for some reason you
028525,000035: ## find that the images are illegible, contact me at info@sandroid.org
028526,000036: ## about getting access to the (much) higher-quality images which Paul
028527,000037: ## actually created.
028528,000038: ##
028529,000039: ## The code has been modified to match LMY99 Revision 0, otherwise
028530,000040: ## known as Luminary Revision 99, the Apollo 11 software release preceeding
028531,000041: ## the listing from which it was transcribed. It has been verified to
028532,000042: ## contain the same bank checksums as AGC developer Allan Klumpp's listing
028533,000043: ## of Luminary Revision 99 (for which we do not have scans).
028534,000044: ##
028535,000045: ## Notations on Allan Klumpp's listing read, in part:
028536,000046: ##
028537,000047: ## ASSEMBLE REVISION 099 OF AGC PROGRAM LUMINARY BY NASA 2021112-51
028538,000048:
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Page 651 |
028540,000050:
028541,000051: # GENERAL LAMBERT AIMPOINT GUIDANCE **
028542,000052: # WRITTEN BY RAMA M AIYAWAR
028543,000053:
028544,000054: # PROGRAM P-31 DESCRIPTION **
028545,000055:
028546,000056: # 1. TO ACCEPT TARGETING PARAMETERS OBTAINED FROM A SOURCE EXTERNAL
028547,000057: # TO THE LEM AND COMPUTE THERE FROM THE REQUIRED-VELOCITY AND
028548,000058: # OTHER INITIAL CONDITIONS REQUIRED BY LM FOR DESIRED MANEUVER.
028549,000059: # THE TARGETING PARAMETERS ARE TIG (TIME OF IGNITION), TARGET
028550,000060: # VECTOR (RTARG), AND THE TIME FROM TIG UNTIL THE TARGET IS
028551,000061: # REACHED (DELLT4), DESIRED TIME OF FLIGHT FROM RINIT TO RTARG..
028552,000062:
028553,000063: # ASSUMPTIONS **
028554,000064:
028555,000065: # 1. THE TARGET PARAMETERS MAY HAVE BEEN LOADED PRIOR TO THE
028556,000066: # EXECUTION OF THIS PROGRAM.
028557,000067: # 2. THIS PROGRAM IS APPLICABLE IN EITHER EARTH OR LUNAR ORBIT.
028558,000068: # 3. THIS PROGRAM IS DESIGNED FOR ONE-MAN OPERATION, AND SHOULD
028559,000069: # BE SELECTED BY THE ASTRONAUT BY DSKY ENTRY V37 E31.
028560,000070:
028561,000071: # SUBROUTINES USED **
028562,000072: #
028563,000073: # MANUPARM, TTG/N35, R02BOTH, MIDGIM, DISPMGA, FLAGDOWN, BANKCALL,
028564,000074: # GOTOPOOH, ENDOFJOB, PHASCHNG, GOFLASHR, GOFLASH.
028565,000075:
028566,000076: # MANUPARM CALCULATES APOGEE, PERIGEE ALTITUDES AND DELTAV DESIRED
028567,000077: # FOR THE MANEUVER.
028568,000078:
028569,000079: # TTG/N35 CLOCKTASK - UPDATES CLOCK.
028570,000080:
028571,000081: # MIDGIM CALCULATES MIDDLE GIMBAL ANGLE FOR DISPLAY.
028572,000082:
028573,000083: # R02BOTH IMU - STATUS CHECK ROUTINE.
028574,000084:
028575,000085: # DISPLAYS USED IN P-31LM **
028576,000086:
028577,000087: # V06N33 DISPLAY SOTRED TIG (IN HRS. MINS. SECS)
028578,000088: # V06N42 DISPLAY APOGEE, PERIGEE, DELTAV.
028579,000089: # V16N35 DISPLAY TIME FROM TIG.
028580,000090: # V06N45 TIME FROM IGNITION AND MIDDLE GIMBAL ANGLE.
028581,000091:
028582,000092: # ERASABLE INITIALIZATION REQUIRED **
028583,000093:
028584,000094: # TIG TIME OF IGNITION DP (B+28) CS.
028585,000095:
028586,000096: # DELLT4 DESIRED TIME OF FLIGHT DP (B+28) CS
028587,000097: # FROM RINIT TO RTARG.
028588,000098:
028589,000099: # RTARG RADIUS VECTOR OF TARGET POSITION VECTOR
028590,000100: # RADIUS VECTOR SCALED TO (B+29)METERS IF EARTH ORBIT
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Page 652 |
028592,000102: # RADIUS VECTOR SCALED TO (B+27)METERS IF MOON ORBIT
028593,000103:
028594,000104: # OUTPUT **
028595,000105:
028596,000106: # HAPO APOGEE ALTITUDE
028597,000107: # HPER PERIGEE ALTITUDE
028598,000108: # VGDISP MAG. OF DELTAV FOR DISPLAY, SCALING B+7 M/CS EARTH
028599,000109: # MAG. OF DELTAV FOR DISPLAY, SCALING B+5 M/CS MOON
028600,000110: # MIDGIM MIDDLE GIMBAL ANGLE
028601,000111: # XDELVFLG RESETS XDELVFLG FOR LAMBERT VG COMPUTATIONS
028602,000112:
028603,000113: # ALARMS OR ABORTS NONE **
028604,000114:
028605,000115: # RESTARTS ARE VIA GROUP 4 **
028606,000116:
028607,000117: 35,2000 SETLOC GLM
028608,000118: 35,2000 BANK
028609,000119:
028610,000120: 35,2450 E7,1470 EBANK= SUBEXIT
028611,000121:
028612,000122: 35,2450 COUNT* $$/P31
028613,000123: 35,2450 02361 P31 TC P20FLGON
028614,000124: 35,2451 32025 CAF V06N33 # TIG
028615,000125: 35,2452 03712 TC VNPOOH
028616,000126: 35,2453 06037 TC INTPRET
028617,000127: 35,2454 71214 CLEAR DLOAD
028618,000128: 35,2455 00670 UPDATFLG
028619,000129: 35,2456 03442 TIG
028620,000130: 35,2457 34041 STCALL TDEC1 # INTEGRATE STATE VECTORS TO TIG
028621,000131: 35,2460 27057 LEMPREC
028622,000132: 35,2461 40375 VLOAD SETPD
028623,000133: 35,2462 00001 RATT
028624,000134: 35,2463 00001 0D
028625,000135: 35,2464 03642 STORE RTIG
028626,000136: 35,2465 26323 STOVL RINIT
028627,000137: 35,2466 00007 VATT
028628,000138: 35,2467 03650 STORE VTIG
028629,000139: 35,2470 16331 STODL VINIT
028630,000140: 35,2471 32420 P30ZERO
028631,000141: 35,2472 65206 PUSH PDDL # E4 AND NUMIT = 0
028632,000142: 35,2473 03452 DELLT4
028633,000143: 35,2474 66015 DAD SXA,1
028634,000144: 35,2475 03442 TIG
028635,000145: 35,2476 02776 RTX1
028636,000146: 35,2477 03631 STORE TPASS4
028637,000147: 35,2500 45134 SXA,2 CALL
028638,000148: 35,2501 02777 RTX2
028639,000149: 35,2502 22000 INITVEL
028640,000150: 35,2503 41575 VLOAD PUSH
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Page 653 |
028642,000152: 35,2504 02366 DELVEET3
028643,000153: 35,2505 03656 STORE DELVSIN
028644,000154: 35,2506 43046 ABVAL CLEAR
028645,000155: 35,2507 01267 XDELVFLG
028646,000156: 35,2510 37664 STCALL VGDISP
028647,000157: 35,2511 15733 GET.LVC
028648,000158: 35,2512 63375 VLOAD PDVL
028649,000159: 35,2513 03642 RTIG
028650,000160: 35,2514 02337 VIPRIME
028651,000161: 35,2515 77624 CALL
028652,000162: 35,2516 46316 PERIAPO1
028653,000163: 35,2517 77624 CALL
028654,000164: 35,2520 46426 SHIFTR1
028655,000165: 35,2521 77624 CALL # LIMIT DISPLAY TO 9999.9 N. MI.
028656,000166: 35,2522 45636 MAXCHK
028657,000167: 35,2523 16321 STODL HPER
028658,000168: 35,2524 00005 4D
028659,000169: 35,2525 77624 CALL
028660,000170: 35,2526 46426 SHIFTR1
028661,000171: 35,2527 77624 CALL # LIMIT DISPLAY TO 9999.9 N. MI.
028662,000172: 35,2530 45636 MAXCHK
028663,000173: 35,2531 02317 STORE HAPO
028664,000174: 35,2532 77776 EXIT
028665,000175: 35,2533 33727 CAF V06N81 # DELVLVC
028666,000176: 35,2534 03712 TC VNPOOH
028667,000177: 35,2535 32026 CAF V06N42 # HAPO, HPER, VGDISP
028668,000178: 35,2536 03712 TC VNPOOH
028669,000179: 35,2537 06037 TC INTPRET
028670,000180: 35,2540 45014 REVN1645 SET CALL # TRKMKCNT, TTOGO, +MGA
028671,000181: 35,2541 01071 FINALFLG
028672,000182: 35,2542 73606 VN1645
028673,000183: 35,2543 77650 GOTO
028674,000184: 35,2544 72540 REVN1645
028675,000185:
End of include-file LAMBERT_AIMPOINT_GUIDANCE.agc. Parent file is MAIN.agc