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 16:27 JULY 14,1969Note that the date is the date of the printout, not the date of the program revision. |
028183,000002: ## Copyright: Public domain.
028184,000003: ## Filename: GROUND_TRACKING_DETERMINATION_PROGRAM.agc
028185,000004: ## Purpose: Part of the source code for Luminary 1A build 099.
028186,000005: ## It is part of the source code for the Lunar Module's (LM)
028187,000006: ## Apollo Guidance Computer (AGC), for Apollo 11.
028188,000007: ## Assembler: yaYUL
028189,000008: ## Contact: Ron Burkey <info@sandroid.org>.
028190,000009: ## Website: www.ibiblio.org/apollo.
028191,000010: ## Pages: 654-657
028192,000011: ## Mod history: 2009-05-18 RSB Adapted from the corresponding
028193,000012: ## Luminary131 file, using page
028194,000013: ## images from Luminary 1A.
028195,000014: ## 2016-12-13 RSB GOTOP00H -> GOTOPOOH
028196,000015: ## 2016-12-14 RSB Proofed text comments with octopus/ProoferComments
028197,000016: ## but no errors found.
028198,000017: ## 2017-03-15 RSB Comment-text fixes identified in 5-way
028199,000018: ## side-by-side diff of Luminary 69/99/116/131/210.
028200,000019:
028201,000020: ## This source code has been transcribed or otherwise adapted from
028202,000021: ## digitized images of a hardcopy from the MIT Museum. The digitization
028203,000022: ## was performed by Paul Fjeld, and arranged for by Deborah Douglas of
028204,000023: ## the Museum. Many thanks to both. The images (with suitable reduction
028205,000024: ## in storage size and consequent reduction in image quality as well) are
028206,000025: ## available online at www.ibiblio.org/apollo. If for some reason you
028207,000026: ## find that the images are illegible, contact me at info@sandroid.org
028208,000027: ## about getting access to the (much) higher-quality images which Paul
028209,000028: ## actually created.
028210,000029: ##
028211,000030: ## Notations on the hardcopy document read, in part:
028212,000031: ##
028213,000032: ## Assemble revision 001 of AGC program LMY99 by NASA 2021112-61
028214,000033: ## 16:27 JULY 14, 1969
028215,000034:
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Page 654 |
028217,000036: # GROUND TRACKING DETERMINATION PROGRAM P21
028218,000037: # PROGRAM DESCRIPTION
028219,000038: # MOD NO - 1
028220,000039: # MOD BY - N. M. NEVILLE
028221,000040:
028222,000041: # FUNCTIONAL DECRIPTION -
028223,000042: # TO PROVIDE THE ASTRONAUT DETAILS OF THE LM OR CSM GROUND TRACK WITHOUT
028224,000043: # THE NEED FOR GROUND COMMUNICATION (REQUESTED BY DSKY).
028225,000044:
028226,000045: # CALLING SEQUENCE -
028227,000046: # ASTRONAUT REQUEST THROUGH DSKY V37E21E
028228,000047:
028229,000048: # SUBROUTINES CALLED -
028230,000049: # GOPERF4
028231,000050: # GOFLASH
028232,000051: # THISPREC
028233,000052: # OTHPREC
028234,000053: # LAT-LONG
028235,000054:
028236,000055: # NORMAL EXIT MODES -
028237,000056: # ASTRONAUT REQUEST TROUGH DSKY TO TERMINATE PROGRAM V34E
028238,000057:
028239,000058: # ALARM OR ABORT EXIT MODES -
028240,000059: # NONE
028241,000060:
028242,000061: # OUTPUT -
028243,000062: # OCTAL DISPLAY OF OPTION CODE AND VEHICLE WHOSE GROUND TRACK IS TO BE
028244,000063: # COMPUTED
028245,000064: # OPTION CODE 00002
028246,000065: # THIS 00001
028247,000066: # OTHER 00002
028248,000067: # DECIMAL DISPLAY OF TIME TO BE INTEGRATED TO HOURS, MINUTES, SECONDS
028249,000068: # DECIMAL DISPLAY OF LAT,LONG,ALT
028250,000069:
028251,000070: # ERASABLE INITIALIZATION REQUIRED
028252,000071: # AX0 2DEC 4.652459653 E-5 RADIANS %68-69 CONSTANTS"
028253,000072: # -AY0 2DEC 2.147535898 E-5 RADIANS
028254,000073: # AZ0 2DEC .7753206164 REVOLUTIONS
028255,000074: # FOR LUNAR ORBITS 504LM VECTOR IS NEEDED
028256,000075: # 504LM 2DEC -2.700340600 E-5 RADIANS
028257,000076: # 504LM _2 2DEC -7.514128400 E-4 RADIANS
028258,000077: # 504LM _4 2DEC _2.553198641 E-4 RADIANS
028259,000078:
028260,000079: # NONE
028261,000080:
028262,000081: # DEBRIS
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Page 655 |
028264,000083: # CENTRALS - A,Q,L
028265,000084: # OTHER - THOSE USED BY THE ABOVE LISTED SUBROUTINES
028266,000085: # SEE LEMPREC, LAT-LONG
028267,000086:
028268,000087: 35,2545 30,2000 SBANK= LOWSUPER # FOR LOW 2CADR'S.
028269,000088:
028270,000089: 33,2200 BANK 33
028271,000090: 24,2000 SETLOC P20S
028272,000091: 24,2000 BANK
028273,000092:
028274,000093: 24,3505 E7,1762 EBANK= P21TIME
028275,000094: 24,3505 COUNT* $$/P21
028276,000095: 24,3505 34753 PROG21 CAF ONE
028277,000096: 24,3506 55145 TS OPTION2 # ASSUMED VEHICLE IS LM, R2 = 00001
028278,000097: 24,3507 34752 CAF BIT2 # OPTION 2
028279,000098: 24,3510 04616 TC BANKCALL
028280,000099: 24,3511 20633 CADR GOPERF4
028281,000100: 24,3512 06001 TC GOTOPOOH # TERMINATE
028282,000101: 24,3513 03515 TC +2 # PROCEED VALUE OF ASSUMED VEHICLE OK
028283,000102: 24,3514 03507 TC -5 # R2 LOADED THROUGH DSKY
028284,000103: 24,3515 33665 P21PROG1 CAF V6N34 # LOAD DESIRED TIME OF LAT-LONG.
028285,000104: 24,3516 04616 TC BANKCALL
028286,000105: 24,3517 20476 CADR GOFLASH
028287,000106: 24,3520 06001 TC GOTOPOOH # TERM
028288,000107: 24,3521 03523 TC +2 # PROCEED VALUES OK
028289,000108: 24,3522 03515 TC -5 # TIME LOADED THROUGH DSKY
028290,000109: 24,3523 06037 TC INTPRET
028291,000110: 24,3524 77745 DLOAD
028292,000111: 24,3525 01046 DSPTEM1
028293,000112: 24,3526 34041 STCALL TDEC1 # INTEGRATE TO TIME SPECIFIED IN TDEC
028294,000113: 24,3527 27414 INTSTALL
028295,000114: 24,3530 43014 BON CLEAR
028296,000115: 24,3531 00304 P21FLAG
028297,000116: 24,3532 51550 P21CONT # ON --- RECYCLE USING BASE VECTOR
028298,000117: 24,3533 01674 VINTFLAG # OFF -- 1ST PASS CALL BASE VECTOR
028299,000118: 24,3534 70535 SLOAD SR1
028300,000119: 24,3535 01146 OPTION2
028301,000120: 24,3536 43030 BHIZ SET
028302,000121: 24,3537 51541 +2 # ZERO -- THIS VEHICLE (LM)
028303,000122: 24,3540 01474 VINTFLAG # ONE -- OTHER VEHICLE (CM)
028304,000123: 24,3541 43014 CLEAR CLEAR
028305,000124: 24,3542 01676 DIM0FLAG
028306,000125: 24,3543 01673 INTYPFLG # PRECISION
028307,000126: 24,3544 77624 CALL
028308,000127: 24,3545 27134 INTEGRV # CALCULATE
028309,000128: 24,3546 77650 GOTO # -AND
028310,000129: 24,3547 51571 P21VSAVE # -SAVE BASE VECTOR
028311,000130: 24,3550 77775 P21CONT VLOAD
028312,000131: 24,3551 03676 P21BASER # RECYCLE -- INTEG FROM BASE VECTOR
028313,000132: 24,3552 25535 STOVL RCV # --POS
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Page 656 |
028315,000134: 24,3553 03704 P21BASEV
028316,000135: 24,3554 15543 STODL VCV # --VEL
028317,000136: 24,3555 03763 P21TIME
028318,000137: 24,3556 01517 STORE TET # --TIME
028319,000138: 24,3557 43014 CLEAR CLEAR
028320,000139: 24,3560 01676 DIM0FLAG
028321,000140: 24,3561 00263 MOONFLAG
028322,000141: 24,3562 53135 SLOAD BZE
028323,000142: 24,3563 01164 P21ORIG
028324,000143: 24,3564 51567 +3 # ZERO = EARTH
028325,000144: 24,3565 77614 SET # ---2 = MOON
028326,000145: 24,3566 00063 MOONFLAG
028327,000146: 24,3567 77624 +3 CALL
028328,000147: 24,3570 27107 INTEGRVS
028329,000148: 24,3571 77745 P21VSAVE DLOAD # SAVE CURRENT BASE VECTOR
028330,000149: 24,3572 00015 TAT
028331,000150: 24,3573 27763 STOVL P21TIME # --TIME
028332,000151: 24,3574 00017 RATT1
028333,000152: 24,3575 27676 STOVL P21BASER # --POS B-29 OR B-27
028334,000153: 24,3576 00025 VATT1
028335,000154: 24,3577 03704 STORE P21BASEV # --VEL B-07 OR B-05
028336,000155: 24,3600 53646 ABVAL SL*
028337,000156: 24,3601 57576 0,2
028338,000157: 24,3602 27712 STOVL P21VEL # VEL/ FOR N91 DISP
028339,000158: 24,3603 00001 RATT
028340,000159: 24,3604 50256 UNIT DOT
028341,000160: 24,3605 00007 VATT # U(R).V
028342,000161: 24,3606 67471 DDV ASIN # U(R).U(V)
028343,000162: 24,3607 03712 P21VEL
028344,000163: 24,3610 03714 STORE P21GAM # SIN-1 U(R).U(V) , -90 TO &90
028345,000164: 24,3611 67334 SXA,2 SLOAD
028346,000165: 24,3612 01163 P21ORIG # 0 = EARTH
028347,000166: 24,3613 01146 OPTION2
028348,000167: 24,3614 46142 SR1 BHIZ
028349,000168: 24,3615 51620 +3
028350,000169: 24,3616 77650 GOTO
028351,000170: 24,3617 51623 +4
028352,000171: 24,3620 77614 +3 BON
028353,000172: 24,3621 04307 SURFFLAG
028354,000173: 24,3622 51625 P21DSP
028355,000174: 24,3623 77614 +4 SET
028356,000175: 24,3624 00064 P21FLAG
028357,000176: 24,3625 67214 P21DSP CLEAR SLOAD # GENERATE DISPLAY DATA
028358,000177: 24,3626 01663 LUNAFLAG
028359,000178: 24,3627 00050 X2
028360,000179: 24,3630 43054 BZE SET
028361,000180: 24,3631 51633 +2 # 0 = EARTH
028362,000181: 24,3632 01463 LUNAFLAG
028363,000182: 24,3633 77775 VLOAD
028364,000183: 24,3634 00001 RATT
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Page 657 |
028366,000185: 24,3635 16032 STODL ALPHAV
028367,000186: 24,3636 00015 TAT
028368,000187: 24,3637 45014 CLEAR CALL
028369,000188: 24,3640 00662 ERADFLAG
028370,000189: 24,3641 26351 LAT-LONG
028371,000190: 24,3642 77605 DMP # MPAC = ALT, METERS B-29
028372,000191: 24,3643 11667 K.01
028373,000192: 24,3644 03716 STORE P21ALT # ALT/100 FOR N91 DISP
028374,000193: 24,3645 77776 EXIT
028375,000194: 24,3646 33664 CAF V06N43 # DISPLAY LAT, LONG, ALT
028376,000195: 24,3647 04616 TC BANKCALL # LAT, LONG = 1/2 REVS B0
028377,000196: 24,3650 20476 CADR GOFLASH # ALT = KM B14
028378,000197: 24,3651 06001 TC GOTOPOOH # TERM
028379,000198: 24,3652 06001 TC GOTOPOOH
028380,000199: 24,3653 06037 TC INTPRET # V32E RECYCLE
028381,000200: 24,3654 43345 DLOAD DAD
028382,000201: 24,3655 03763 P21TIME
028383,000202: 24,3656 11663 600SEC # 600 SECONDS OR 10 MIN
028384,000203: 24,3657 01046 STORE DSPTEM1
028385,000204: 24,3660 77634 RTB
028386,000205: 24,3661 51515 P21PROG1
028387,000206: 24,3662 00003 25140 600SEC 2DEC 60000 B-28 # 10 MIN
028388,000207:
028389,000208: 24,3664 01453 V06N43 VN 00643
028390,000209: 24,3665 01442 V6N34 VN 00634
028391,000210: 24,3666 00243 32703 K.01 2DEC .01
028392,000211:
End of include-file GROUND_TRACKING_DETERMINATION_PROGRAM_-_P21.agc. Parent file is MAIN.agc