Source Code
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These source-code files were from the printout at the MIT Museum, with many thanks
to Deborah Douglas, the Museum's Curator of Science and Technology, for releasing
it to us. The printout was digitally photographed by Paul Fjeld. A team of
volunteers transcribed the source code manually from these images or, where
appropriate, modified already-transcribed but similar source Luminary 131 (Apollo 13)
source code to agree with the images from the printout. Note that the page images
presented online are of reduced quality, and that higher-quality images
are 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 001 OF AGC PROGRAM LMY99 BY NASA 2021112-061 20'35 OCT. 28,1968Note that the date is the date of the printout, not the date of the program revision. |
015241,000002: ## Copyright: Public domain.
015242,000003: ## Filename: GIMBAL_LOCK_AVOIDANCE.agc
015243,000004: ## Purpose: Part of the source code for Luminary 1A build 099.
015244,000005: ## It is part of the source code for the Lunar Module's (LM)
015245,000006: ## Apollo Guidance Computer (AGC), for Apollo 11.
015246,000007: ## Assembler: yaYUL
015247,000008: ## Contact: Ron Burkey <info@sandroid.org>.
015248,000009: ## Website: www.ibiblio.org/apollo.
015249,000010: ## Pages: 364
015250,000011: ## Mod history: 2009-05-17 RSB Adapted from the corresponding
015251,000012: ## Luminary131 file, using page
015252,000013: ## images from Luminary 1A.
015253,000014: ## 2010-12-31 JL Fixed page number comment.
015254,000015: ## 2016-12-14 RSB Proofed text comments with octopus/ProoferComments
015255,000016: ## but no errors found.
015256,000017: ##
015257,000018: ## This source code has been transcribed or otherwise adapted from
015258,000019: ## digitized images of a hardcopy from the MIT Museum. The digitization
015259,000020: ## was performed by Paul Fjeld, and arranged for by Deborah Douglas of
015260,000021: ## the Museum. Many thanks to both. The images (with suitable reduction
015261,000022: ## in storage size and consequent reduction in image quality as well) are
015262,000023: ## available online at www.ibiblio.org/apollo. If for some reason you
015263,000024: ## find that the images are illegible, contact me at info@sandroid.org
015264,000025: ## about getting access to the (much) higher-quality images which Paul
015265,000026: ## actually created.
015266,000027: ##
015267,000028: ## Notations on the hardcopy document read, in part:
015268,000029: ##
015269,000030: ## Assemble revision 001 of AGC program LMY99 by NASA 2021112-61
015270,000031: ## 16:27 JULY 14, 1969
015271,000032:
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Page 364 |
015273,000034: 15,2050 BANK 15
015274,000035:
015275,000036: 22,2000 SETLOC KALCMON1
015276,000037: 22,2000 BANK
015277,000038:
015278,000039: # DETECTING GIMBAL LOCK
015279,000040: 22,2744 22,2744 LOCSKIRT EQUALS NOGIMLOC
015280,000041:
015281,000042: 22,2744 77614 NOGIMLOC SET
015282,000043: 22,2745 01074 CALCMAN3
015283,000044: 22,2746 70740 WCALC LXC,1 DLOAD*
015284,000045: 22,2747 01325 RATEINDX # CHOOSE THE DESIRED MANEUVER RATE
015285,000046: 22,2750 04772 ARATE,1 # FROM A LIST OF FOUR
015286,000047: 22,2751 45002 SR4 CALL # COMPUTE THE INCREMENTAL ROTATION MATRIX
015287,000048: 22,2752 44527 DELCOMP # DEL CORRESPONDING TO A 1 SEC ROTATION
015288,000049: # ABOUT COF
015289,000050: 22,2753 74343 DLOAD* VXSC
015290,000051: 22,2754 04772 ARATE,1
015291,000052: 22,2755 03271 COF
015292,000053: 22,2756 17326 STODL BRATE # COMPONENT MANEUVER RATES 45 DEG/SEC
015293,000054: 22,2757 03336 AM
015294,000055: 22,2760 55605 DMP DDV*
015295,000056: 22,2761 05002 ANGLTIME
015296,000057: 22,2762 04772 ARATE,1
015297,000058: 22,2763 77661 SR
015298,000059: 22,2764 20606 5
015299,000060: 22,2765 03334 STORE TM # MANEUVER EXECUTION TIME SCALED AS T2
015300,000061: 22,2766 77614 SETGO
015301,000062: 22,2767 01035 CALCMAN2 # D(OFF) = CONTINUE MANEUVER
015302,000063: 22,2770 45010 NEWANGL +1 # 1(ON) = START MANEUVER
015303,000064:
015304,000065: # THE FOUR SELECTABLE FREE FALL MANEUVER RATES SELECTED BY
015305,000066: # LOADING RATEINDX WITH 0, 2, 4, 6, RESPECTIVELY
015306,000067:
015307,000068: 22,2771 00221 24255 ARATE 2DEC .0088888888 # = 0.2 DEG/SEC $ 22.5 DEG/SEC
015308,000069:
015309,000070: 22,2773 00554 02660 2DEC .0222222222 # = 0.5 DEG/SEC $ 22.5 DEG/SEC
015310,000071:
015311,000072: 22,2775 02660 13301 2DEC .0888888888 # = 2.0 DEG/SEC $ 22.5 DEG/SEC
015312,000073:
015313,000074: 22,2777 16161 30707 2DEC .4444444444 # = 10.0 DEG/SEC $ 22.5 DEG/SEC
015314,000075:
015315,000076: 22,3001 00003 04000 ANGLTIME 2DEC .0001907349 # = 100B-19 FUDGE FACTOR TO CONVERT
015316,000077: # MANEUVER ANGLE TO MANEUVER TIME
015317,000078:
015318,000079:
End of include-file GIMBAL_LOCK_AVOIDANCE.agc. Parent file is MAIN.agc