Source Code
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These source-code files derive from a printout of Luminary 116 (the Apollo 12
Lunar Module guidance computer program), from the personal library of
original AGC developer Don Eyles, digitally photographed at archive.org,
financially sponsored by Ron Burkey, and transcribed to source code by a
team of volunteers. This colorized, syntax-highlighted form was created
by assembling that transcribed source code. Note that the full page images
are available on the
Virtual AGC project page at archive.org, while reduced-size images
are presented at the VirtualAGC project website. Report or fix any
transcription errors at
the Virtual AGC project code repository. Notations on the program listing read, in part: GAP: ASSEMBLE REVISION 116 OF AGC PROGRAM LUMINARY BY NASA 2021112-071 19:09 AUG. 11,1969Note that the date is the date of the printout, not the date of the program revision. |
033246,000002: ## Copyright: Public domain.
033247,000003: ## Filename: THE_LUNAR_LANDING.agc
033248,000004: ## Purpose: A section of Luminary revision 116.
033249,000005: ## It is part of the source code for the Lunar Module's (LM)
033250,000006: ## Apollo Guidance Computer (AGC) for Apollo 12.
033251,000007: ## This file is intended to be a faithful transcription, except
033252,000008: ## that the code format has been changed to conform to the
033253,000009: ## requirements of the yaYUL assembler rather than the
033254,000010: ## original YUL assembler.
033255,000011: ## Reference: pp. 778-785
033256,000012: ## Assembler: yaYUL
033257,000013: ## Contact: Ron Burkey <info@sandroid.org>.
033258,000014: ## Website: www.ibiblio.org/apollo/index.html
033259,000015: ## Mod history: 2017-01-22 MAS Created from Luminary 99.
033260,000016: ## 2017-03-10 HG Transcribed
033261,000017: ## 2017-03-14 RSB Proofed comment text via 3-way diff vs
033262,000018: ## Luminary 99 and 131.
033263,000019: ## 2017-03-16 RSB Comment-text fixes identified in 5-way
033264,000020: ## side-by-side diff of Luminary 69/99/116/131/210.
033265,000021: ## 2017-03-19 HG Fix SELOC operand F2DPS*31 --> F2DPS*34
033266,000022:
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Page 778 |
033268,000024: 32,2777 BANK 32
033269,000025: 32,2000 SETLOC F2DPS*32
033270,000026: 32,2000 BANK
033271,000027:
033272,000028: 32,2777 E7,1621 EBANK= E2DPS
033273,000029:
033274,000030: # ****************************************
033275,000031: # P63: THE LUNAR LANDING, BRAKING PHASE
033276,000032: # ****************************************
033277,000033:
033278,000034: 32,2777 COUNT* $$/P63
033279,000035:
033280,000036: 32,2777 05353 P63LM TC PHASCHNG
033281,000037: 32,3000 04024 OCT 04024
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Note: The above label (P63LM) has a box in blue pen drawn arround it The two statements above are circled with a blue pen arround them |
033284,000040:
033285,000041: 32,3001 04616 TC BANKCALL # DO IMU STATUS CHECK ROUTINE R02
033286,000042: 32,3002 11236 CADR R02BOTH
033287,000043:
033288,000044: 32,3003 33254 CAF P63ADRES # INITIALIZE WHICH FOR BURNBABY
033289,000045: 32,3004 55455 TS WHICH
033290,000046:
033291,000047: 32,3005 32000 CAF DPSTHRSH # INITIALIZE DVMON
033292,000048: 32,3006 55250 TS DVTHRUSH
033293,000049: 32,3007 34751 CAF FOUR
033294,000050: 32,3010 55515 TS DVCNTR
033295,000051:
033296,000052: 32,3011 44753 CS ONE # INITIALIZE WCHPHASE AND FLPASSO
033297,000053: 32,3012 55346 TS WCHPHASE
033298,000054:
033299,000055: 32,3013 34755 CA ZERO
033300,000056: 32,3014 55623 TS FLPASS0
033301,000057:
033302,000058: 32,3015 44736 CS BIT14
033303,000059: 32,3016 00006 EXTEND
033304,000060: 32,3017 03012 WAND CHAN12 # REMOVE TRACK-ENABLE DISCRETE.
033305,000061:
033306,000062: 32,3020 06042 FLAGORGY TC INTPRET # DIONYSIAN FLAG WAVING
033307,000063: 32,3021 43014 CLEAR CLEAR
033308,000064: 32,3022 02663 NOTHROTL
033309,000065: 32,3023 03271 REDFLAG
033310,000066: 32,3024 43014 CLEAR SET
033311,000067: 32,3025 05660 LRBYPASS
033312,000068: 32,3026 03067 MUNFLAG
033313,000069: 32,3027 43014 CLEAR CLEAR
033314,000070: 32,3030 00266 P25FLAG # TERMINATE P25 IF IT IS RUNNING.
033315,000071: 32,3031 00270 RNDVZFLG # TERMINATE P20 IF IT IS RUNNING
033316,000072:
033317,000073: # ****************************************
033318,000074:
033319,000075: 32,3032 77201 IGNALG SETPD VLOAD # FIRST SET UP INPUTS FOR RP-TO-R:-
033320,000076:
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Page 779 |
033322,000078: 32,3033 00001 0 # AT 0D LANDING SITE IN MOON FIXED FRAME
033323,000079: 32,3034 02023 RLS # AT 6D ESTIMATED TIME OF LANDING
033324,000080: 32,3035 41525 PDDL PUSH # MPAC NON-ZERO TO INDICATE LUNAR CASE
033325,000081: 32,3036 02401 TLAND
033326,000082: 32,3037 37625 STCALL TPIP # ALSO SET TPIP FOR FIRST GUIDANCE PASS
033327,000083: 32,3040 55716 RP-TO-R
033328,000084: 32,3041 64312 VSL4 MXV
033329,000085: 32,3042 01734 REFSMMAT
033330,000086: 32,3043 37635 STCALL LAND
033331,000087: 32,3044 71343 GUIDINIT # GUIDINIT INITIALIZES WM AND /LAND/
033332,000088: 32,3045 45345 DLOAD DSU
033333,000089: 32,3046 02401 TLAND
033334,000090: 32,3047 25261 GUIDDURN
033335,000091: 32,3050 34041 STCALL TDEC1 # INTEGRATE STATE FORWARD TO THAT TIME
033336,000092: 32,3051 27060 LEMPREC
033337,000093: 32,3052 77331 SSP VLOAD
033338,000094: 32,3053 03647 NIGNLOOP
033339,000095: 32,3054 00050 40D
033340,000096: 32,3055 06522 UNITX
033341,000097: 32,3056 26575 STOVL CG
033342,000098: 32,3057 06520 UNITY
033343,000099: 32,3060 26603 STOVL CG +6
033344,000100: 32,3061 06516 UNITZ
033345,000101: 32,3062 16611 STODL CG +14
033346,000102: 32,3063 25257 99999CON
033347,000103: 32,3064 27665 STOVL DELTAH # INITIALIZE DELTAH FOR V16N68 DISPLAY
033348,000104: 32,3065 06524 ZEROVECS
033349,000105: 32,3066 17254 STODL UNFC/2 # INITIALIZE TRIM VELOCITY CORRECTION TERM
033350,000106: 32,3067 06524 HI6ZEROS
033351,000107: 32,3070 03643 STORE TTF/8
033352,000108:
033353,000109: 32,3071 77745 IGNALOOP DLOAD
033354,000110: 32,3072 00015 TAT
033355,000111: 32,3073 27561 STOVL PIPTIME1
033356,000112: 32,3074 00017 RATT1
033357,000113: 32,3075 64312 VSL4 MXV
033358,000114: 32,3076 01734 REFSMMAT
033359,000115: 32,3077 37521 STCALL R
033360,000116: 32,3100 67067 MUNGRAV
033361,000117: 32,3101 35236 STCALL GDT/2
033362,000118: 32,3102 62402 ?GUIDSUB # WHICH DELIVERS N PASSES OF GUIDANCE
033363,000119:
033364,000120: # DDUMCALC IS PROGRAMMED AS FOLLOWS:-
033365,000121:
033366,000122: # 2 -
033367,000123: # (RIGNZ - RGU )/16 + 16(RGU )KIGNY/B8 + (RGU - RIGNX)KIGNX/B4 + (ABVAL(VGU) - VIGN)KIGNV/B4
033368,000124: # 2 1 0
033369,000125: # DDUM = -------------------------------------------------------------------------------------------
033370,000126: # 10
033371,000127: # 2 (VGU - 16 VGU KIGNX/B4)
033372,000128:
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Page 780 |
033374,000130: # 2 0
033375,000131:
033376,000132: # THE NUMERATOR IS SCALED IN METERS AT 2(28). THE DENOMINATOR IS A VELOCITY IN UNITS OF 2(10)M/CS.
033377,000133: # THE QUOTIENT IS THUS A TIME IN UNITS OF 2(18) CENTISECONDS. THE FINAL SHIFT RESCALES TO UNITS OF 2(28) CS.
033378,000134: # THERE IS NO DAMPING FACTOR. THE CONSTANTS KIGNX/B4, KIGNY/B8 AND KIGNV/B4 ARE ALL NEGATIVE IN SIGN.
033379,000135:
033380,000136: 32,3103 55646 DDUMCALC TS NIGNLOOP
033381,000137: 32,3104 06042 TC INTPRET
033382,000138: 32,3105 57345 DLOAD DMPR # FORM DENOMINATOR FIRST
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Note: The above operator and operand are separately underlined with a black pen. The corresponding octal opcode in the resulting listing is marked with a box around it in black pen. |
033385,000141: 32,3106 03627 VGU
033386,000142: 32,3107 02501 KIGNX/B4
033387,000143: 32,3110 44232 SL4R BDSU
033388,000144: 32,3111 03633 VGU +4
033389,000145: 32,3112 45325 PDDL DSU
033390,000146: 32,3113 02477 RIGNZ
033391,000147: 32,3114 02633 RGU +4
033392,000148: 32,3115 65222 SR4R PDDL
033393,000149: 32,3116 02631 RGU +2
033394,000150: 32,3117 57316 DSQ DMPR
033395,000151: 32,3120 02503 KIGNY/B8
033396,000152: 32,3121 65232 SL4R PDDL
033397,000153: 32,3122 02627 RGU
033398,000154: 32,3123 57225 DSU DMPR
033399,000155: 32,3124 02475 RIGNX
033400,000156: 32,3125 02501 KIGNX/B4
033401,000157: 32,3126 51515 PDVL ABVAL
033402,000158: 32,3127 03627 VGU
033403,000159: 32,3130 57225 DSU DMPR
033404,000160: 32,3131 02473 VIGN
033405,000161: 32,3132 02505 KIGNV/B4
033406,000162: 32,3133 43215 DAD DAD
033407,000163: 32,3134 56215 DAD DDV
033408,000164: 32,3135 77661 SRR
033409,000165: 32,3136 21613 10D
033410,000166:
033411,000167: 32,3137 43206 PUSH DAD
033412,000168: 32,3140 03561 PIPTIME1
033413,000169: 32,3141 14041 STODL TDEC1 # STORE NEW GUESS FOR NEXT INTEGRATION
033414,000170: 32,3142 45246 ABS DSU
033415,000171: 32,3143 25263 DDUMCRIT
033416,000172: 32,3144 45040 BMN CALL
033417,000173: 32,3145 65164 DDUMGOOD
033418,000174: 32,3146 27412 INTSTALL
033419,000175: 32,3147 43014 SET SET
033420,000176: 32,3150 01473 INTYPFLG
033421,000177: 32,3151 00063 MOONFLAG
033422,000178: 32,3152 77745 DLOAD
033423,000179: 32,3153 03561 PIPTIME1
033424,000180: 32,3154 25517 STOVL TET # HOPEFULLY ?GUIDSUB DID NOT
033425,000181: 32,3155 00017 RATT1 # CLOBBER RATT1 AND VATT1
033426,000182:
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Page 781 |
033428,000184: 32,3156 25535 STOVL RCV
033429,000185: 32,3157 00025 VATT1
033430,000186: 32,3160 35543 STCALL VCV
033431,000187: 32,3161 27110 INTEGRVS
033432,000188: 32,3162 77650 GOTO
033433,000189: 32,3163 65071 IGNALOOP
033434,000190:
033435,000191: 32,3164 54335 DDUMGOOD SLOAD SR
033436,000192: 32,3165 03423 ZOOMTIME
033437,000193: 32,3166 20617 14D
033438,000194: 32,3167 77621 BDSU
033439,000195: 32,3170 00041 TDEC1
033440,000196: 32,3171 27442 STOVL TIG # COMPUTE DISTANCE LANDING SITE WILL BE
033441,000197: 32,3172 03527 V # OUT OF LM'S ORBITAL PLANE AT IGNITION:
033442,000198: 32,3173 53435 VXV UNIT # SIGN IS + IF LANDING SITE IS TO THE
033443,000199: 32,3174 03521 R # RIGHT, NORTH; - IF TO THE LEFT, SOUTH.
033444,000200: 32,3175 72441 DOT SL1
033445,000201: 32,3176 03635 LAND
033446,000202: 32,3177 26617 R60INIT STOVL OUTOFPLN # INITIALIZATION FOR CALCMANU
033447,000203: 32,3200 03254 UNFC/2
033448,000204: 32,3201 02621 STORE R60VSAVE # STORE UNFC/2 TEMPORARILY IN R60SAVE
033449,000205: 32,3202 77776 EXIT
033450,000206: # ****************************************
033451,000207:
033452,000208: 32,3203 05353 IGNALGRT TC PHASCHNG # PREVENT REPEATING IGNALG
033453,000209: 32,3204 04024 OCT 04024
033454,000210:
033455,000211: 32,3205 44362 ASTNCLOK CS ASTNDEX
033456,000212: 32,3206 04616 TC BANKCALL
033457,000213: 32,3207 74670 CADR STCLOK2
033458,000214: 32,3210 15155 TCF ENDOFJOB # RETURN IN NEW JOB AND IN EBANK FIVE
033459,000215:
033460,000216: 32,3211 06042 ASTNRET TC INTPRET
033461,000217: 32,3212 47131 SSP RTB # GO PICK UP DISPLAY AT END OF R51:
033462,000218: 32,3213 02747 QMAJ # "PROCEED" WILL DO A FINE ALIGNMENT
033463,000219: 32,3214 65216 FCADR P63SPOT2 # "ENTER" WILL RETURN TO P63SPOT2
033464,000220: 32,3215 31127 R51P63
033465,000221: 32,3216 53575 P63SPOT2 VLOAD UNIT # INITIALIZE KALCMANU FOR BURN ATTITUDE
033466,000222: 32,3217 02621 R60VSAVE
033467,000223: 32,3220 27773 STOVL POINTVSM
033468,000224: 32,3221 06522 UNITX
033469,000225: 32,3222 03765 STORE SCAXIS
033470,000226: 32,3223 77776 EXIT
033471,000227:
033472,000228: 32,3224 35016 CAF EBANK7
033473,000229: 32,3225 54003 TS EBANK
033474,000230:
033475,000231: 32,3226 00004 INHINT
033476,000232: 32,3227 04674 TC IBNKCALL
033477,000233: 32,3230 40143 CADR PFLITEDB
033478,000234:
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Page 782 |
033480,000236: 32,3231 00003 RELINT
033481,000237:
033482,000238: 32,3232 04616 TC BANKCALL
033483,000239: 32,3233 54123 CADR R60LEM
033484,000240:
033485,000241: 32,3234 05353 TC PHASCHNG # PREVENT RECALLING R60
033486,000242: 32,3235 04024 OCT 04024
033487,000243:
033488,000244: 32,3236 34746 P63SPOT3 CA BIT6 # IS THE LR ANTENNA IN POSITION 1 YET
033489,000245: 32,3237 00006 EXTEND
033490,000246: 32,3240 02033 RAND CHAN33
033491,000247: 32,3241 00006 EXTEND
033492,000248: 32,3242 13250 BZF P63SPOT4 # BRANCH IF ANTENNA ALREADY IN POSITION 1
033493,000249:
033494,000250: 32,3243 33255 CAF CODE500 # ASTRONAUT: PLEASE CRANK THE
033495,000251: 32,3244 04616 TC BANKCALL # SILLY THING AROUND
033496,000252: 32,3245 20624 CADR GOPERF1
033497,000253: 32,3246 16001 TCF GOTOPOOH # TERMINATE
033498,000254: 32,3247 13236 TCF P63SPOT3 # PROCEED SEE IF HE'S LYING
033499,000255:
033500,000256: 32,3250 04616 P63SPOT4 TC BANKCALL # ENTER INITIALIZE LANDING RADAR
033501,000257: 32,3251 67703 CADR SETPOS1
033502,000258:
033503,000259: 32,3252 04635 TC POSTJUMP # OFF TO SEE THE WIZARD...
033504,000260: 32,3253 74130 CADR BURNBABY
033505,000261:
033506,000262:
033507,000263: # ---------------------------------------
033508,000264:
033509,000265: # CONSTANTS FOR P63LM AND IGNALG
033510,000266:
033511,000267:
033512,000268: 32,3254 02100 P63ADRES GENADR P63TABLE
033513,000269:
033514,000270:
033515,000271: 32,3255 4362 ASTNDEX = MD1 # OCT 25; INDEX FOR CLOKTASK
033516,000272:
033517,000273: 32,3255 00500 CODE500 OCT 00500
033518,000274:
033519,000275:
033520,000276: 32,3256 00035 30373 99999CON 2DEC 30479.7 B-24
033521,000277: 32,3260 00004 01610 GUIDDURN 2DEC +66440 B-28 # GUIDDURN +6.64400314 E+2
033522,000278: 32,3262 00000 00010 DDUMCRIT 2DEC +8 B-28 # CRITERION FOR IGNALG CONVERGENCE
033523,000279:
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Page 783 |
033525,000281: # ----------------------------------------
033526,000282:
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Page 784 |
033528,000284: # ****************************************
033529,000285: # P68: LANDING CONFIRMATION
033530,000286: # ****************************************
033531,000287:
033532,000288: 34,3271 BANK 34
033533,000289: 34,2000 SETLOC F2DPS*34
033534,000290: 34,2000 BANK
033535,000291:
033536,000292: 34,3271 COUNT* $$/P6567
033537,000293:
033538,000294: 34,3271 05353 LANDJUNK TC PHASCHNG
033539,000295: 34,3272 04024 OCT 04024
033540,000296:
033541,000297: 34,3273 00004 INHINT
033542,000298: 34,3274 04616 TC BANKCALL # ZERO ATTITUDE ERROR
033543,000299: 34,3275 40154 CADR ZATTEROR
033544,000300:
033545,000301: 34,3276 06042 TC INTPRET # TO INTERPRETIVE AS TIME IS NOT CRITICAL
033546,000302: 34,3277 77614 SET # PREVENT RCS JET FIRINGS IF MODE CONT IS
033547,000303: 34,3300 06460 PULSEFLG # IN ATT HOLD
033548,000304: 34,3301 43014 SET CLEAR
033549,000305: 34,3302 04067 SURFFLAG
033550,000306: 34,3303 04666 LETABORT
033551,000307: 34,3304 77214 SET VLOAD
033552,000308: 34,3305 05062 APSFLAG
033553,000309: 34,3306 01220 RN
033554,000310: 34,3307 16032 STODL ALPHAV
033555,000311: 34,3310 01234 PIPTIME
033556,000312: 34,3311 45014 SET CALL
033557,000313: 34,3312 01463 LUNAFLAG
033558,000314: 34,3313 26351 LAT-LONG
033559,000315: 34,3314 77201 SETPD VLOAD # COMPUTE RLS AND STORE IT AWAY
033560,000316: 34,3315 00001 0
033561,000317: 34,3316 01220 RN
033562,000318: 34,3317 65352 VSL2 PDDL
033563,000319: 34,3320 01234 PIPTIME
033564,000320: 34,3321 45006 PUSH CALL
033565,000321: 34,3322 51677 R-TO-RP
033566,000322: 34,3323 02023 STORE RLS
033567,000323: 34,3324 77776 EXIT
033568,000324: 34,3325 33342 CAF V06N43* # ASTRONAUT: NOW LOOK WHERE YOU ENDED UP
033569,000325: 34,3326 04616 TC BANKCALL
033570,000326: 34,3327 20477 CADR GOFLASH
033571,000327: 34,3330 16001 TCF GOTOPOOH # TERMINATE
033572,000328: 34,3331 13333 TCF +2 # PROCEED
033573,000329: 34,3332 13325 TCF -5 # RECYCLE
033574,000330:
033575,000331:
033576,000332: 34,3333 06042 TC INTPRET
033577,000333: 34,3334 77775 VLOAD # INITIALIZE GSAV AND (USING REFMF)
033578,000334:
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Page 785 |
033580,000336: 34,3335 06522 UNITX # YNBSAV, ZNBSAV AND ATTFLAG FOR P57
033581,000337: 34,3336 36231 STCALL GSAV
033582,000338: 34,3337 33471 REFMF
033583,000339: 34,3340 77776 EXIT
033584,000340:
033585,000341: 34,3341 16001 TCF GOTOPOOH # ASTRONAUT: PLEASE SELECT P57
033586,000342:
033587,000343:
033588,000344: 34,3342 01453 V06N43* VN 0643
End of include-file THE_LUNAR_LANDING.agc. Parent file is MAIN.agc