Source Code
|
These source-code files are part of a reconstructed copy of LM131 revision 1,
the final release of the Apollo 13 Lunar Module (LM) Apollo Guidance Computer
(AGC) software.
The source reconstruction began with source code of Luminary 131 previously
transcribed from a digitized copy of that program. A dump of the flight spare
core rope memory module B5, part number 2010802-171, serial number RAY 411,
was obtained. This module is the only module different between Luminary 131
and LM131 revision 1. The dump was disassembled and all changes were incorporated
into these source files. Note that page numbers in the reconstructed code match
those on the Luminary 131 printout, although the changed code would likely have
changed page numbers for a real LM131 revision 1 listing.
Comments from the original source code are prefixed with a single '#' symbol,
whereas comments added later are prefixed by "##" or "###". Report any errors
noted by creating an
issue report at the Virtual AGC
project's GitHub repository.
|
032988,000002: ## Copyright: Public domain.
032989,000003: ## Filename: THE_LUNAR_LANDING.agc
032990,000004: ## Purpose: A section of LM131 revision 1.
032991,000005: ## It is part of the reconstructed source code for the final
032992,000006: ## release of the flight software for the Lunar Module's (LM)
032993,000007: ## Apollo Guidance Computer (AGC) for Apollo 13. The code has
032994,000008: ## been reconstructed from a listing of Luminary 131 and a dump
032995,000009: ## of a core rope memory module B5, part number 2010802-171,
032996,000010: ## which is the only module different between LM131 revision 1
032997,000011: ## and Luminary 131. The executable generated from this source
032998,000012: ## has been verified against the module dump, so while the names,
032999,000013: ## comments, and ordering may not be exactly correct, the
033000,000014: ## resulting binary is.
033001,000015: ## Reference: pp. 780-787
033002,000016: ## Assembler: yaYUL
033003,000017: ## Contact: Ron Burkey <info@sandroid.org>.
033004,000018: ## Website: www.ibiblio.org/apollo/index.html
033005,000019: ## Mod history: 2022-10-28 MAS Created from Luminary 131.
033006,000020:
|
|
Page 780
|
033008,000022: 32,3000 BANK 32
033009,000023: 32,2000 SETLOC F2DPS*32
033010,000024: 32,2000 BANK
033011,000025:
033012,000026: 32,3000 E7,1621 EBANK= E2DPS
033013,000027:
033014,000028: # ****************************************
033015,000029: # P63: THE LUNAR LANDING, BRAKING PHASE
033016,000030: # ****************************************
033017,000031:
033018,000032: 32,3000 COUNT* $$/P63
033019,000033:
033020,000034: 32,3000 05353 P63LM TC PHASCHNG
033021,000035: 32,3001 04024 OCT 04024
033022,000036:
033023,000037: 32,3002 04616 TC BANKCALL # DO IMU STATUS CHECK ROUTINE R02
033024,000038: 32,3003 11233 CADR R02BOTH
033025,000039:
033026,000040: 32,3004 33255 CAF P63ADRES # INITIALIZE WHICH FOR BURNBABY
033027,000041: 32,3005 55455 TS WHICH
033028,000042:
033029,000043: 32,3006 32000 CAF DPSTHRSH # INITIALIZE DVMON
033030,000044: 32,3007 55250 TS DVTHRUSH
033031,000045: 32,3010 34751 CAF FOUR
033032,000046: 32,3011 55515 TS DVCNTR
033033,000047:
033034,000048: 32,3012 44753 CS ONE # INITIALIZE WCHPHASE AND FLPASSO
033035,000049: 32,3013 55346 TS WCHPHASE
033036,000050:
033037,000051: 32,3014 34755 CA ZERO
033038,000052: 32,3015 55623 TS FLPASS0
033039,000053:
033040,000054: 32,3016 44736 CS BIT14
033041,000055: 32,3017 00006 EXTEND
033042,000056: 32,3020 03012 WAND CHAN12 # REMOVE TRACK-ENABLE DISCRETE.
033043,000057:
033044,000058: 32,3021 06042 FLAGORGY TC INTPRET # DIONYSIAN FLAG WAVING
033045,000059: 32,3022 43014 CLEAR CLEAR
033046,000060: 32,3023 02663 NOTHROTL
033047,000061: 32,3024 03271 REDFLAG
033048,000062: 32,3025 43014 CLEAR SET
033049,000063: 32,3026 05660 LRBYPASS
033050,000064: 32,3027 03067 MUNFLAG
033051,000065: 32,3030 43014 CLEAR CLEAR
033052,000066: 32,3031 00266 P25FLAG # TERMINATE P25 IF IT IS RUNNING.
033053,000067: 32,3032 00270 RNDVZFLG # TERMINATE P20 IF IT IS RUNNING
033054,000068:
033055,000069: # ****************************************
033056,000070:
033057,000071: 32,3033 77201 IGNALG SETPD VLOAD # FIRST SET UP INPUTS FOR RP-TO-R:-
|
|
Page 781
|
033059,000073: 32,3034 00001 0 # AT 0D LANDING SITE IN MOON FIXED FRAME
033060,000074: 32,3035 02023 RLS # AT 6D ESTIMATED TIME OF LANDING
033061,000075: 32,3036 41525 PDDL PUSH # MPAC NON-ZERO TO INDICATE LUNAR CASE
033062,000076: 32,3037 02401 TLAND
033063,000077: 32,3040 37625 STCALL TPIP # ALSO SET TPIP FOR FIRST GUIDANCE PASS
033064,000078: 32,3041 55716 RP-TO-R
033065,000079: 32,3042 64312 VSL4 MXV
033066,000080: 32,3043 01734 REFSMMAT
033067,000081: 32,3044 37635 STCALL LAND
033068,000082: 32,3045 71343 GUIDINIT # GUIDINIT INITIALIZES WM AND /LAND/
033069,000083: 32,3046 45345 DLOAD DSU
033070,000084: 32,3047 02401 TLAND
033071,000085: 32,3050 25262 GUIDDURN
033072,000086: 32,3051 34041 STCALL TDEC1 # INTEGRATE STATE FORWARD TO THAT TIME
033073,000087: 32,3052 27056 LEMPREC
033074,000088: 32,3053 77331 SSP VLOAD
033075,000089: 32,3054 03647 NIGNLOOP
033076,000090: 32,3055 00050 40D
033077,000091: 32,3056 06522 UNITX
033078,000092: 32,3057 26575 STOVL CG
033079,000093: 32,3060 06520 UNITY
033080,000094: 32,3061 26603 STOVL CG +6
033081,000095: 32,3062 06516 UNITZ
033082,000096: 32,3063 16611 STODL CG +14
033083,000097: 32,3064 25260 99999CON
033084,000098: 32,3065 27665 STOVL DELTAH # INITIALIZE DELTAH FOR V16N68 DISPLAY
033085,000099: 32,3066 06524 ZEROVECS
033086,000100: 32,3067 17253 STODL UNFC/2 # INITIALIZE TRIM VELOCITY CORRECTION TERM
033087,000101: 32,3070 06524 HI6ZEROS
033088,000102: 32,3071 03643 STORE TTF/8
033089,000103:
033090,000104: 32,3072 77745 IGNALOOP DLOAD
033091,000105: 32,3073 00015 TAT
033092,000106: 32,3074 27561 STOVL PIPTIME1
033093,000107: 32,3075 00017 RATT1
033094,000108: 32,3076 64312 VSL4 MXV
033095,000109: 32,3077 01734 REFSMMAT
033096,000110: 32,3100 37521 STCALL R
033097,000111: 32,3101 67067 MUNGRAV
033098,000112: 32,3102 35236 STCALL GDT/2
033099,000113: 32,3103 62415 ?GUIDSUB # WHICH DELIVERS N PASSES OF GUIDANCE
033100,000114:
033101,000115: # DDUMCALC IS PROGRAMMED AS FOLLOWS:-
033102,000116: # 2 -
033103,000117: # (RIGNZ - RGU )/16 + 16(RGU )KIGNY/B8 + (RGU - RIGNX)KIGNX/B4 + (ABVAL(VGU) - VIGN)KIGNV/B4
033104,000118: # 2 1 0
033105,000119: # DDUM = -------------------------------------------------------------------------------------------
033106,000120: # 10
033107,000121: # 2 (VGU - 16 VGU KIGNX/B4)
|
|
Page 782
|
033109,000123: # 2 0
033110,000124: # THE NUMERATOR IS SCALED IN METERS AT 2(28). THE DENOMINATOR IS A VELOCITY IN UNITS OF 2(10) M/CS.
033111,000125: # THE QUOTIENT IS THUS A TIME IN UNITS OF 2(18) CENTISECONDS. THE FINAL SHIFT RESCALES TO UNITS OF 2(28) CS.
033112,000126: # THERE IS NO DAMPING FACTOR. THE CONSTANTS KIGNX/B4, KIGNY/B8 AND KIGNV/B4 ARE ALL NEGATIVE IN SIGN.
033113,000127:
033114,000128: 32,3104 55646 DDUMCALC TS NIGNLOOP
033115,000129: 32,3105 06042 TC INTPRET
033116,000130: 32,3106 57345 DLOAD DMPR # FORM DENOMINATOR FIRST
033117,000131: 32,3107 03627 VGU
033118,000132: 32,3110 02501 KIGNX/B4
033119,000133: 32,3111 44232 SL4R BDSU
033120,000134: 32,3112 03633 VGU +4
033121,000135: 32,3113 45325 PDDL DSU
033122,000136: 32,3114 02477 RIGNZ
033123,000137: 32,3115 02633 RGU +4
033124,000138: 32,3116 65222 SR4R PDDL
033125,000139: 32,3117 02631 RGU +2
033126,000140: 32,3120 57316 DSQ DMPR
033127,000141: 32,3121 02503 KIGNY/B8
033128,000142: 32,3122 65232 SL4R PDDL
033129,000143: 32,3123 02627 RGU
033130,000144: 32,3124 57225 DSU DMPR
033131,000145: 32,3125 02475 RIGNX
033132,000146: 32,3126 02501 KIGNX/B4
033133,000147: 32,3127 51515 PDVL ABVAL
033134,000148: 32,3130 03627 VGU
033135,000149: 32,3131 57225 DSU DMPR
033136,000150: 32,3132 02473 VIGN
033137,000151: 32,3133 02505 KIGNV/B4
033138,000152: 32,3134 43215 DAD DAD
033139,000153: 32,3135 56215 DAD DDV
033140,000154: 32,3136 77661 SRR
033141,000155: 32,3137 21613 10D
033142,000156:
033143,000157: 32,3140 43206 PUSH DAD
033144,000158: 32,3141 03561 PIPTIME1
033145,000159: 32,3142 14041 STODL TDEC1 # STORE NEW GUESS FOR NEXT INTEGRATION
033146,000160: 32,3143 45246 ABS DSU
033147,000161: 32,3144 25264 DDUMCRIT
033148,000162: 32,3145 45040 BMN CALL
033149,000163: 32,3146 65165 DDUMGOOD
033150,000164: 32,3147 27410 INTSTALL
033151,000165: 32,3150 43014 SET SET
033152,000166: 32,3151 01473 INTYPFLG
033153,000167: 32,3152 00063 MOONFLAG
033154,000168: 32,3153 77745 DLOAD
033155,000169: 32,3154 03561 PIPTIME1
033156,000170: 32,3155 25517 STOVL TET # HOPEFULLY ?GUIDSUB DID NOT
033157,000171: 32,3156 00017 RATT1 # CLOBBER RATT1 AND VATT1
|
|
Page 783
|
033159,000173: 32,3157 25535 STOVL RCV
033160,000174: 32,3160 00025 VATT1
033161,000175: 32,3161 35543 STCALL VCV
033162,000176: 32,3162 27106 INTEGRVS
033163,000177: 32,3163 77650 GOTO
033164,000178: 32,3164 65072 IGNALOOP
033165,000179:
033166,000180: 32,3165 54335 DDUMGOOD SLOAD SR
033167,000181: 32,3166 03423 ZOOMTIME
033168,000182: 32,3167 20617 14D
033169,000183: 32,3170 77621 BDSU
033170,000184: 32,3171 00041 TDEC1
033171,000185: 32,3172 27442 STOVL TIG # COMPUTE DISTANCE LANDING SITE WILL BE
033172,000186: 32,3173 03527 V # OUT OF LM'S ORBITAL PLANE AT IGNITION:
033173,000187: 32,3174 53435 VXV UNIT # SIGN IS + IF LANDING SITE IS TO THE
033174,000188: 32,3175 03521 R # RIGHT, NORTH; - IF TO THE LEFT, SOUTH.
033175,000189: 32,3176 72441 DOT SL1
033176,000190: 32,3177 03635 LAND
033177,000191: 32,3200 26617 R60INIT STOVL OUTOFPLN # INITIALIZATION FOR CALCMANU
033178,000192: 32,3201 03253 UNFC/2
033179,000193: 32,3202 02621 STORE R60VSAVE # STORE UNFC/2 TEMPORARILY IN R60SAVE
033180,000194: 32,3203 77776 EXIT
033181,000195: # ****************************************
033182,000196:
033183,000197: 32,3204 05353 IGNALGRT TC PHASCHNG # PREVENT REPEATING IGNALG
033184,000198: 32,3205 04024 OCT 04024
033185,000199:
033186,000200: 32,3206 44362 ASTNCLOK CS ASTNDEX
033187,000201: 32,3207 04616 TC BANKCALL
033188,000202: 32,3210 74670 CADR STCLOK2
033189,000203: 32,3211 15155 TCF ENDOFJOB # RETURN IN NEW JOB AND IN EBANK FIVE
033190,000204:
033191,000205: 32,3212 06042 ASTNRET TC INTPRET
033192,000206: 32,3213 47131 SSP RTB # GO PICK UP DISPLAY AT END OF R51:
033193,000207: 32,3214 02747 QMAJ # "PROCEED" WILL DO A FINE ALIGNMENT
033194,000208: 32,3215 65217 FCADR P63SPOT2 # "ENTER" WILL RETURN TO P63SPOT2
033195,000209: 32,3216 31127 R51P63
033196,000210: 32,3217 53575 P63SPOT2 VLOAD UNIT # INITIALIZE KALCMANU FOR BURN ATTITUDE
033197,000211: 32,3220 02621 R60VSAVE
033198,000212: 32,3221 27773 STOVL POINTVSM
033199,000213: 32,3222 06522 UNITX
033200,000214: 32,3223 03765 STORE SCAXIS
033201,000215: 32,3224 77776 EXIT
033202,000216:
033203,000217: 32,3225 35016 CAF EBANK7
033204,000218: 32,3226 54003 TS EBANK
033205,000219:
033206,000220: 32,3227 00004 INHINT
033207,000221: 32,3230 04674 TC IBNKCALL
033208,000222: 32,3231 40143 CADR PFLITEDB
|
|
Page 784
|
033210,000224: 32,3232 00003 RELINT
033211,000225:
033212,000226: 32,3233 04616 TC BANKCALL
033213,000227: 32,3234 54123 CADR R60LEM
033214,000228:
033215,000229: 32,3235 05353 TC PHASCHNG # PREVENT RECALLING R60
033216,000230: 32,3236 04024 OCT 04024
033217,000231:
033218,000232: 32,3237 34746 P63SPOT3 CA BIT6 # IS THE LR ANTENNA IN POSITION 1 YET
033219,000233: 32,3240 00006 EXTEND
033220,000234: 32,3241 02033 RAND CHAN33
033221,000235: 32,3242 00006 EXTEND
033222,000236: 32,3243 13251 BZF P63SPOT4 # BRANCH IF ANTENNA ALREADY IN POSITION 1
033223,000237:
033224,000238: 32,3244 33256 CAF CODE500 # ASTRONAUT: PLEASE CRANK THE
033225,000239: 32,3245 04616 TC BANKCALL # SILLY THING AROUND
033226,000240: 32,3246 20624 CADR GOPERF1
033227,000241: 32,3247 16001 TCF GOTOPOOH # TERMINATE
033228,000242: 32,3250 13237 TCF P63SPOT3 # PROCEED SEE IF HE'S LYING
033229,000243:
033230,000244: 32,3251 04616 P63SPOT4 TC BANKCALL # ENTER INITIALIZE LANDING RADAR
033231,000245: 32,3252 67701 CADR SETPOS1
033232,000246:
033233,000247: 32,3253 04635 TC POSTJUMP # OFF TO SEE THE WIZARD ...
033234,000248: 32,3254 74130 CADR BURNBABY
033235,000249:
033236,000250: # ----------------------------------------
033237,000251:
033238,000252: # CONSTANTS FOR P63LM AND IGNALG
033239,000253:
033240,000254: 32,3255 02100 P63ADRES GENADR P63TABLE
033241,000255:
033242,000256: 32,3256 4362 ASTNDEX = MD1 # OCT 25; INDEX FOR CLOKTASK
033243,000257:
033244,000258: 32,3256 00500 CODE500 OCT 00500
033245,000259:
033246,000260: 32,3257 00035 30373 99999CON 2DEC 30479.7 B-24
033247,000261:
033248,000262: 32,3261 00004 01610 GUIDDURN 2DEC +66440 B-28 # GUIDDURN +6.64400314 E+2
033249,000263: 32,3263 00000 00010 DDUMCRIT 2DEC +8 B-28 # CRITERION FOR IGNALG CONVERGENCE
033250,000264:
|
|
Page 785
|
033252,000266: # ----------------------------------------
033253,000267:
|
|
Page 786
|
033255,000269: # ****************************************
033256,000270: # P68: LANDING CONFIRMATION
033257,000271: # ****************************************
033258,000272:
033259,000273: 34,3271 BANK 34
033260,000274: 34,2000 SETLOC F2DPS*34
033261,000275: 34,2000 BANK
033262,000276:
033263,000277: 34,3271 COUNT* $$/P6567
033264,000278:
033265,000279: 34,3271 05353 LANDJUNK TC PHASCHNG
033266,000280: 34,3272 04024 OCT 04024
033267,000281:
033268,000282: 34,3273 00004 INHINT
033269,000283: 34,3274 04616 TC BANKCALL # ZERO ATTITUDE ERROR
033270,000284: 34,3275 40154 CADR ZATTEROR
033271,000285:
033272,000286: 34,3276 06042 TC INTPRET # TO INTERPRETIVE AS TIME IS NOT CRITICAL
033273,000287: 34,3277 77614 SET # PREVENT RCS JET FIRINGS IF MODE CONT IS
033274,000288: 34,3300 06460 PULSEFLG # IN ATT HOLD
033275,000289: 34,3301 43014 SET CLEAR
033276,000290: 34,3302 04067 SURFFLAG
033277,000291: 34,3303 04666 LETABORT
033278,000292: 34,3304 77214 SET VLOAD
033279,000293: 34,3305 05062 APSFLAG
033280,000294: 34,3306 01220 RN
033281,000295: 34,3307 16032 STODL ALPHAV
033282,000296: 34,3310 01234 PIPTIME
033283,000297: 34,3311 45014 SET CALL
033284,000298: 34,3312 01463 LUNAFLAG
033285,000299: 34,3313 26347 LAT-LONG
033286,000300: 34,3314 77201 SETPD VLOAD # COMPUTE RLS AND STORE IT AWAY
033287,000301: 34,3315 00001 0
033288,000302: 34,3316 01220 RN
033289,000303: 34,3317 65352 VSL2 PDDL
033290,000304: 34,3320 01234 PIPTIME
033291,000305: 34,3321 45006 PUSH CALL
033292,000306: 34,3322 51700 R-TO-RP
033293,000307: 34,3323 02023 STORE RLS
033294,000308: 34,3324 77776 EXIT
033295,000309: 34,3325 33342 CAF V06N43* # ASTRONAUT: NOW LOOK WHERE YOU ENDED UP
033296,000310: 34,3326 04616 TC BANKCALL
033297,000311: 34,3327 20477 CADR GOFLASH
033298,000312: 34,3330 16001 TCF GOTOPOOH # TERMINATE
033299,000313: 34,3331 13333 TCF +2 # PROCEED
033300,000314: 34,3332 13325 TCF -5 # RECYCLE
033301,000315:
033302,000316: 34,3333 06042 TC INTPRET
033303,000317: 34,3334 77775 VLOAD # INITIALIZE GSAV AND (USING REFMF)
|
|
Page 787
|
033305,000319: 34,3335 06522 UNITX # YNBSAV, ZNBSAV AND ATTFLAG FOR P57
033306,000320: 34,3336 36231 STCALL GSAV
033307,000321: 34,3337 33471 REFMF
033308,000322: 34,3340 77776 EXIT
033309,000323:
033310,000324: 34,3341 16001 TCF GOTOPOOH # ASTRONAUT: PLEASE SELECT P57
033311,000325:
033312,000326: 34,3342 01453 V06N43* VN 0643
033313,000327:
End of include-file THE_LUNAR_LANDING.agc. Parent file is MAIN.agc