Source Code
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These source-code files are part of a reconstructed copy of Luminary 69/2,
the flown, final release of the Apollo 10 Lunar Module (LM) Apollo Guidance Computer (AGC) software.
The reconstruction is based on the source code of Luminary 69 — i.e., the
initial, unflown version, "revision 0" — of which
a contemporary listing was available. The code was then updated by incorporating the
differences between Luminary 69 and Luminary 69/2, known from other contemporary
documentation. The only such difference is the implementation in
Luminary 69/2 of the "R-2 Lunar Potential Model", the source code for which was taken
from program Luminary 99/1 (Apollo 11 LM), of which a contemporary listing was also available.
Finally, the now-reconstructed Luminary 69/2 was then validated by assembling it to
executable form and verifying that its memory banks had the correct checksums,
known from still other contemporary documentation.
Note that page numbers in the reconstructed code match those in the original Luminary 69
program listing, or in the ORBITAL INTEGRATION log section, in Luminary 99/1. Page numbers
would certainly differ somewhat in a contemporary Luminary 69/2 listing.
Moreover, annotations that were not present in the contemporary source code have been added
to the reconstructed code to justify each change in Luminary 69/2 relative to
Luminary 69. Here's a guide to the Apollo documentation referenced in those annotations:
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.
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036916,000002: ## Copyright: Public domain.
036917,000003: ## Filename: P12.agc
036918,000004: ## Purpose: A section of LUM69 revision 2.
036919,000005: ## It is part of the reconstructed source code for the flown
036920,000006: ## version of the flight software for the Lunar Module's (LM)
036921,000007: ## Apollo Guidance Computer (AGC) for Apollo 10. The code has
036922,000008: ## been recreated from a copy of Luminary revsion 069, using
036923,000009: ## changes present in Luminary 099 which were described in
036924,000010: ## Luminary memos 75 and 78. The code has been adapted such
036925,000011: ## that the resulting bugger words exactly match those specified
036926,000012: ## for LUM69 revision 2 in NASA drawing 2021152B, which gives
036927,000013: ## relatively high confidence that the reconstruction is correct.
036928,000014: ## Reference: pp. 839-843
036929,000015: ## Assembler: yaYUL
036930,000016: ## Contact: Ron Burkey <info@sandroid.org>.
036931,000017: ## Website: www.ibiblio.org/apollo/index.html
036932,000018: ## Mod history: 2019-07-27 MAS Created from Luminary 69.
036933,000019:
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Page 839
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036935,000021: 24,3504 BANK 24
036936,000022: 30,2000 SETLOC P12
036937,000023: 30,2000 BANK
036938,000024:
036939,000025: 30,2006 E7,1513 EBANK= DVCNTR
036940,000026: 30,2006 COUNT* $$/P12
036941,000027:
036942,000028: 30,2006 05353 P12LM TC PHASCHNG
036943,000029: 30,2007 04024 OCT 04024
036944,000030:
036945,000031: 30,2010 04616 TC BANKCALL
036946,000032: 30,2011 11175 CADR R02BOTH # CHECK THE STATUS OF THE IMU.
036947,000033:
036948,000034: 30,2012 05504 TC UPFLAG
036949,000035: 30,2013 00141 ADRES MUNFLAG
036950,000036:
036951,000037: 30,2014 05504 TC UPFLAG # INSURE 4-JET TRANSLATION CAPABILITY.
036952,000038: 30,2015 00307 ADRES ACC4-2FL
036953,000039:
036954,000040: 30,2016 05504 TC UPFLAG # PREVENT R10 FROM ISSUING CROSS-POINTER
036955,000041: 30,2017 00015 ADRES R10FLAG # OUTPUTS.
036956,000042:
036957,000043: 30,2020 05516 TC DOWNFLAG # CLEAR RENDEZVOUS FLAG FOR P22
036958,000044: 30,2021 00010 ADRES RNDVZFLG
036959,000045:
036960,000046: 30,2022 36000 CAF THRESH2 # INITIALIZE DVMON
036961,000047: 30,2023 55251 TS DVTHRUSH
036962,000048: 30,2024 34751 CAF FOUR
036963,000049: 30,2025 55513 TS DVCNTR
036964,000050:
036965,000051: 30,2026 34755 CA ZERO
036966,000052: 30,2027 55460 TS TRKMKCNT # SHOW THAT R29 DOWNLINK DATA ISN'T READY.
036967,000053: 30,2030 33044 CAF V06N33A
036968,000054: 30,2031 04616 TC BANKCALL # FLASH TIG
036969,000055: 30,2032 20351 CADR GOFLASH
036970,000056: 30,2033 16001 TCF GOTOPOOH
036971,000057: 30,2034 12036 TCF +2 # PROCEED
036972,000058: 30,2035 12030 TCF -5 # ENTER
036973,000059:
036974,000060: 30,2036 05353 TC PHASCHNG
036975,000061: 30,2037 04024 OCT 04024
036976,000062:
036977,000063: 30,2040 06036 TC INTPRET
036978,000064: 30,2041 77624 CALL # INITIALIZE WM AND /LAND/
036979,000065: 30,2042 60264 GUIDINIT
036980,000066: 30,2043 45014 SET CALL
036981,000067: 30,2044 04464 FLPI
036982,000068: 30,2045 60204 P12INIT
036983,000069:
036984,000070: 30,2046 77745 P12LMB DLOAD
036985,000071: 30,2047 25604 (TGO)A # SET TGO TO AN INITIAL NOMINAL VALUE.
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Page 840
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036987,000073: 30,2050 17515 STODL TGO
036988,000074: 30,2051 03440 TIG
036989,000075: 30,2052 34041 STCALL TDEC1
036990,000076: 30,2053 27057 LEMPREC # ROTATE THE STATE VECTORS TO THE
036991,000077: 30,2054 64375 VLOAD MXV # IGNITION TIME.
036992,000078: 30,2055 00007 VATT
036993,000079: 30,2056 01734 REFSMMAT
036994,000080: 30,2057 77772 VSL1
036995,000081: 30,2060 27577 STOVL V1S # COMPUTE V1S = VEL(TIG)*2(-7) M/CS.
036996,000082: 30,2061 00001 RATT
036997,000083: 30,2062 52521 MXV VSL6
036998,000084: 30,2063 01734 REFSMMAT
036999,000085: 30,2064 37517 STCALL R # COMPUTE R = POS(TIG)*2(-24) M.
037000,000086: 30,2065 67162 MUNGRAV # COMPUTE GDT1/2(TIG)*2(-7)M/CS.
037001,000087: 30,2066 53575 VLOAD UNIT
037002,000088: 30,2067 03517 R
037003,000089: 30,2070 37535 STCALL UNIT/R/ # COMPUTE UNIT/R/ FOR YCOMP.
037004,000090: 30,2071 57316 YCOMP
037005,000091: 30,2072 57461 SR DCOMP
037006,000092: 30,2073 20606 5D
037007,000093: 30,2074 17641 STODL XRANGE # INITIALIZE XRANGE FOR NOUN 76.
037008,000094: 30,2075 20312 (APO)
037009,000095: 30,2076 03643 STORE APO # INITIALIZE APO FOR NOUN 76.
037010,000096: 30,2077 77776 EXIT
037011,000097:
037012,000098: 30,2100 05353 TC PHASCHNG
037013,000099: 30,2101 04024 OCT 04024
037014,000100:
037015,000101: 30,2102 33043 NEWLOAD CAF V06N76 # FLASH CROSS-RANGE AND APOLUNE VALUES.
037016,000102: 30,2103 04616 TC BANKCALL
037017,000103: 30,2104 20351 CADR GOFLASH
037018,000104: 30,2105 16001 TCF GOTOPOOH
037019,000105: 30,2106 12110 TCF +2 # PROCEED
037020,000106: 30,2107 12102 TCF NEWLOAD # ENTER NEW DATA.
037021,000107:
037022,000108: 30,2110 32306 CAF P12ADRES
037023,000109: 30,2111 55453 TS WHICH
037024,000110:
037025,000111: 30,2112 05353 TC PHASCHNG
037026,000112: 30,2113 04024 OCT 04024
037027,000113:
037028,000114: 30,2114 06036 TC INTPRET
037029,000115: 30,2115 54345 DLOAD SL
037030,000116: 30,2116 03641 XRANGE
037031,000117: 30,2117 20206 5D
037032,000118: 30,2120 77615 DAD
037033,000119: 30,2121 02341 Y
037034,000120: 30,2122 17631 STODL YCO
037035,000121: 30,2123 03643 APO # RA = APO + /LAND/
037036,000122: 30,2124 77661 SL
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Page 841
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037038,000124: 30,2125 20206 5D
037039,000125: 30,2126 41415 DAD PUSH # RA*2(-24) IN MPAC AND PDL
037040,000126: 30,2127 02337 /LAND/
037041,000127: 30,2130 65205 DMP PDDL # 2 RA MU*2(-62) IN PDL, LOAD RA
037042,000128: 30,2131 20003 MUM(-37)
037043,000129: 30,2132 41215 DAD DMP # (RA+RP)*2(-24)
037044,000130: 30,2133 03627 RCO # RP(RA+RP)*2(-48)
037045,000131: 30,2134 03627 RCO
037046,000132: 30,2135 75465 BDDV SQRT # 2 MU RA/RP(RA+RP)*2(-14)=ZDOTD(2)
037047,000133: 30,2136 77626 STADR
037048,000134: 30,2137 51504 STOVL ZDOTD
037049,000135: 30,2140 03535 UNIT/R/
037050,000136: 30,2141 53361 VXSC VAD
037051,000137: 30,2142 20310 49FPS
037052,000138: 30,2143 03577 V1S
037053,000139: 30,2144 03525 STORE V # V(TIPOVER) = V(IGN) + 57FPS (UNIT/R/)
037054,000140: 30,2145 77614 SETGO
037055,000141: 30,2146 04421 FLVR
037056,000142: 30,2147 60313 ASCENT
037057,000143: 30,2150 77745 P12RET DLOAD
037058,000144: 30,2151 02365 ATP # ATP(2)*2(18)
037059,000145: 30,2152 65316 DSQ PDDL
037060,000146: 30,2153 02361 ATY # ATY(2)*2(18)
037061,000147: 30,2154 43316 DSQ DAD
037062,000148: 30,2155 75454 BZE SQRT
037063,000149: 30,2156 60162 YAWDUN
037064,000150: 30,2157 55352 SL1 BDDV
037065,000151: 30,2160 02361 ATY
037066,000152: 30,2161 77736 ARCSIN
037067,000153: 30,2162 26367 YAWDUN STOVL YAW
037068,000154: 30,2163 03252 UNFC/2
037069,000155: 30,2164 50256 UNIT DOT
037070,000156: 30,2165 03535 UNIT/R/
037071,000157: 30,2166 65552 SL1 ARCCOS
037072,000158: 30,2167 77676 DCOMP
037073,000159: 30,2170 02371 STORE PITCH
037074,000160: 30,2171 77776 EXIT
037075,000161: 30,2172 05353 TC PHASCHNG
037076,000162: 30,2173 04024 OCT 04024
037077,000163:
037078,000164: 30,2174 05516 TC DOWNFLAG
037079,000165: 30,2175 00213 ADRES FLPI
037080,000166:
037081,000167: 30,2176 00004 INHINT
037082,000168: 30,2177 04674 TC IBNKCALL
037083,000169: 30,2200 40142 CADR PFLITEDB
037084,000170: 30,2201 00003 RELINT
037085,000171:
037086,000172: 30,2202 04635 TC POSTJUMP
037087,000173: 30,2203 74124 CADR BURNBABY
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Page 842
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037089,000175: 30,2204 77745 P12INIT DLOAD # INITIALIZE ENGINE DATA. USED FOR P12 AND
037090,000176: 30,2205 24001 (1/DV)A # P71.
037091,000177: 30,2206 03637 STORE 1/DV3
037092,000178: 30,2207 03635 STORE 1/DV2
037093,000179: 30,2210 17633 STODL 1/DV1
037094,000180: 30,2211 24005 (AT)A
037095,000181: 30,2212 16257 STODL AT
037096,000182: 30,2213 24007 (TBUP)A
037097,000183: 30,2214 16265 STODL TBUP
037098,000184: 30,2215 34013 ATDECAY
037099,000185: 30,2216 54276 DCOMP SL
037100,000186: 30,2217 20214 11D
037101,000187: 30,2220 02263 STORE TTO
037102,000188: 30,2221 57535 SLOAD DCOMP
037103,000189: 30,2222 26001 APSVEX
037104,000190: 30,2223 77702 SR2
037105,000191: 30,2224 02261 STORE VE
037106,000192: 30,2225 43414 BOFF RVQ
037107,000193: 30,2226 04747 FLAP
037108,000194: 30,2227 60230 COMMINIT
037109,000195: 30,2230 43345 COMMINIT DLOAD DAD # INITIALIZE TARGET DATA. USED BY P12, P70
037110,000196: 30,2231 25602 HINJECT # AND P71 IF IT DOES NOT FOLLOW P70.
037111,000197: 30,2232 02337 /LAND/
037112,000198: 30,2233 17627 STODL RCO
037113,000199: 30,2234 06424 HI6ZEROS
037114,000200: 30,2235 03654 STORE TXO
037115,000201: 30,2236 03631 STORE YCO
037116,000202: 30,2237 02267 STORE RDOTD
037117,000203: 30,2240 26271 STOVL YDOTD
037118,000204: 30,2241 01563 VRECTCSM
037119,000205: 30,2242 64235 VXV MXV
037120,000206: 30,2243 01555 RRECTCSM
037121,000207: 30,2244 01734 REFSMMAT
037122,000208: 30,2245 77656 UNIT
037123,000209: 30,2246 17716 STODL QAXIS
037124,000210: 30,2247 02506 ABTVINJ2 # TENTATIVELY STORE LOW INJECTION VELOCITY
037125,000211: 30,2250 02273 STORE ZDOTD
037126,000212: 30,2251 77614 BON
037127,000213: 30,2252 04704 FLPI
037128,000214: 30,2253 60263 LOVEL
037129,000215: 30,2254 45335 SLOAD DSU
037130,000216: 30,2255 02503 TBRKPNT # TBRKPNT-TGO
037131,000217: 30,2256 03515 TGO
037132,000218: 30,2257 71240 BMN DLOAD # IF TGO>TBRKPNT,LOW VINJECT IS OK;RETURN
037133,000219: 30,2260 60263 LOVEL
037134,000220: 30,2261 02504 ABTVINJ1 # FOR TGO.TBRKPNT USE HI VELOCITY.
037135,000221: 30,2262 02273 STORE ZDOTD
037136,000222: 30,2263 77616 LOVEL RVQ
037137,000223: 30,2264 40220 GUIDINIT STQ SETPD
037138,000224: 30,2265 01164 TEMPR60
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Page 843
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037140,000226: 30,2266 00001 0D
037141,000227: 30,2267 41575 VLOAD PUSH
037142,000228: 30,2270 06416 UNITZ
037143,000229: 30,2271 41434 RTB PUSH
037144,000230: 30,2272 21462 LOADTIME
037145,000231: 30,2273 45135 SLOAD CALL
037146,000232: 30,2274 20312 (APO)
037147,000233: 30,2275 51504 RP-TO-R
037148,000234: 30,2276 74321 MXV VXSC
037149,000235: 30,2277 01734 REFSMMAT
037150,000236: 30,2300 20005 MOONRATE
037151,000237: 30,2301 26331 STOVL WM
037152,000238: 30,2302 02023 RLS
037153,000239: 30,2303 52446 ABVAL SL3
037154,000240: 30,2304 36337 STCALL /LAND/
037155,000241: 30,2305 01164 TEMPR60
037156,000242:
037157,000243: 30,2306 02022 P12ADRES REMADR P12TABLE # NOT IN SAME BANK.
037158,000244: 30,2307 00046 07374 49FPS 2DEC .149352 B-6 # EXPECTED RDOT AT TIPOVER
037159,000245:
037160,000246: 30,2311 00001 26227 (APO) 2DEC 55597.5 B-29 # 30 N.M. EXPRESSED IN METERS.
End of include-file P12.agc. Parent file is MAIN.agc