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. |
053476,000002: ## Copyright: Public domain.
053477,000003: ## Filename: INFLIGHT_ALIGNMENT_ROUTINES.agc
053478,000004: ## Purpose: Part of the source code for Luminary 1A build 099.
053479,000005: ## It is part of the source code for the Lunar Module's (LM)
053480,000006: ## Apollo Guidance Computer (AGC), for Apollo 11.
053481,000007: ## Assembler: yaYUL
053482,000008: ## Contact: Ron Burkey <info@sandroid.org>.
053483,000009: ## Website: www.ibiblio.org/apollo.
053484,000010: ## Pages: 1249-1258
053485,000011: ## Mod history: 2009-05-26 RSB Adapted from the corresponding
053486,000012: ## Luminary131 file, using page
053487,000013: ## images from Luminary 1A.
053488,000014: ## 2016-12-17 RSB Proofed text comments with octopus/ProoferComments
053489,000015: ## and corrected the errors found.
053490,000016: ## 2017-03-17 RSB Comment-text fixes identified in diff'ing
053491,000017: ## Luminary 99 vs Comanche 55.
053492,000018:
053493,000019: ## This source code has been transcribed or otherwise adapted from
053494,000020: ## digitized images of a hardcopy from the MIT Museum. The digitization
053495,000021: ## was performed by Paul Fjeld, and arranged for by Deborah Douglas of
053496,000022: ## the Museum. Many thanks to both. The images (with suitable reduction
053497,000023: ## in storage size and consequent reduction in image quality as well) are
053498,000024: ## available online at www.ibiblio.org/apollo. If for some reason you
053499,000025: ## find that the images are illegible, contact me at info@sandroid.org
053500,000026: ## about getting access to the (much) higher-quality images which Paul
053501,000027: ## actually created.
053502,000028: ##
053503,000029: ## Notations on the hardcopy document read, in part:
053504,000030: ##
053505,000031: ## Assemble revision 001 of AGC program LMY99 by NASA 2021112-61
053506,000032: ## 16:27 JULY 14, 1969
053507,000033:
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Page 1249 |
053509,000035: 22,3773 BANK 22
053510,000036: 23,2000 SETLOC INFLIGHT
053511,000037: 23,2000 BANK
053512,000038:
053513,000039: 23,3247 E5,1642 EBANK= XSM
053514,000040:
053515,000041: # CALCGTA COMPUTES THE GYRO TORQUE ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
053516,000042:
053517,000043: # THE INPUT IS THE DESIRED STABLE MEMBER COORDINATES REFERRED TO PRESENT STABLE MEMBER COORDINATES. THE THREE
053518,000044: # HALF-UNIT VECTORS ARE STORED AT XDC, YDC, AND ZDC.
053519,000045:
053520,000046: # THE OUTPUTS ARE THE THREE GYRO TORQUING ANGLES TO BE APPLIED TO THE Y, Z, AND X GYROS AND ARE STORED DP AT IGC,
053521,000047: # MGC, AND OGC RESPECTIVELY.
053522,000048:
053523,000049: 23,3247 COUNT* $$/INFLT
053524,000050: 23,3247 71220 CALCGTA ITA DLOAD # PUSHDOWN 00-03, 16D-27D, 34D-37D
053525,000051: 23,3250 00051 S2 # XDC = (XD1 XD2 XD3)
053526,000052: 23,3251 02665 XDC # YDC = (YD1 YD2 YD3)
053527,000053: 23,3252 65325 PDDL PDDL # ZDC = (ZD1 ZD2 ZD3)
053528,000054: 23,3253 06522 HI6ZEROS
053529,000055: 23,3254 02671 XDC +4
053530,000056: 23,3255 55476 DCOMP VDEF
053531,000057: 23,3256 77656 UNIT
053532,000058: 23,3257 14027 STODL ZPRIME # ZP = UNIT(-XD3 0 XD1) = (ZP1 ZP2 ZP3)
053533,000059: 23,3260 00027 ZPRIME
053534,000060:
053535,000061: 23,3261 77742 SR1
053536,000062: 23,3262 14023 STODL SINTH # SIN(IGC) = ZP1
053537,000063: 23,3263 00033 ZPRIME +4
053538,000064: 23,3264 77742 SR1
053539,000065: 23,3265 34021 STCALL COSTH # COS(IGC) = ZP3
053540,000066: 23,3266 47320 ARCTRIG
053541,000067:
053542,000068: 23,3267 16742 STODL IGC # Y GYRO TORQUING ANGLE FRACTION OF REV.
053543,000069: 23,3270 02667 XDC +2
053544,000070: 23,3271 77742 SR1
053545,000071: 23,3272 14023 STODL SINTH # SIN(MGC) = XD2
053546,000072: 23,3273 00027 ZPRIME
053547,000073:
053548,000074: 23,3274 65205 DMP PDDL
053549,000075: 23,3275 02671 XDC +4 # PD00 = (ZP1)(XD3)
053550,000076: 23,3276 00033 ZPRIME +4
053551,000077:
053552,000078: 23,3277 45205 DMP DSU
053553,000079: 23,3300 02665 XDC # MPAC = (ZP3)(XD1)
053554,000080: 23,3301 77626 STADR
053555,000081: 23,3302 43756 STCALL COSTH # COS(MGC) = MPAC - PD00
053556,000082: 23,3303 47320 ARCTRIG
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Page 1250 |
053558,000084: 23,3304 26744 STOVL MGC # Z GYRO TORQUING ANGLE FRACTION OF REV.
053559,000085: 23,3305 00027 ZPRIME
053560,000086: 23,3306 77641 DOT
053561,000087: 23,3307 02701 ZDC
053562,000088: 23,3310 24021 STOVL COSTH # COS(OGC) = ZP . ZDC
053563,000089: 23,3311 00027 ZPRIME
053564,000090: 23,3312 77641 DOT
053565,000091: 23,3313 02673 YDC
053566,000092: 23,3314 34023 STCALL SINTH # SIN(OGC) = ZP . YDC
053567,000093: 23,3315 47320 ARCTRIG
053568,000094:
053569,000095: 23,3316 36740 STCALL OGC # X GYRO TORQUING ANGLE FRACTION OF REV.
053570,000096: 23,3317 00051 S2
053571,000097:
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Page 1251 |
053573,000099: # ARCTRIG COMPUTES AN ANGLE GIVEN THE SINE AND COSINE OF THIS ANGLE.
053574,000100:
053575,000101: # THE INPUTS ARE SIN/4 AND COS/4 STORED DP AT SINTH AND COSTH.
053576,000102:
053577,000103: # THE OUTPUT IS THE CALCULATED ANGLE BETWEEN +.5 AND -.5 REVOLUTIONS AND STORED AT THETA. THE OUTPUT IS ALSO
053578,000104: # AVAILABLE AT MPAC.
053579,000105:
053580,000106: 23,3320 51545 ARCTRIG DLOAD ABS # PUSHDOWN 16D-21D
053581,000107: 23,3321 00023 SINTH
053582,000108: 23,3322 50025 DSU BMN
053583,000109: 23,3323 07534 QTSN45 # ABS(SIN/4) - SIN(45)/4
053584,000110: 23,3324 47333 TRIG1 # IF (-45,45) OR (135,-135)
053585,000111:
053586,000112: 23,3325 72545 DLOAD SL1 # (45,135) OR (-135,-45)
053587,000113: 23,3326 00021 COSTH
053588,000114: 23,3327 75326 ACOS SIGN
053589,000115: 23,3330 00023 SINTH
053590,000116: 23,3331 00025 STORE THETA # X = ARCCOS(COS) WITH SIGN(SIN)
053591,000117: 23,3332 77616 RVQ
053592,000118:
053593,000119: 23,3333 72545 TRIG1 DLOAD SL1 # (-45,45) OR (135,-135)
053594,000120: 23,3334 00023 SINTH
053595,000121: 23,3335 77736 ASIN
053596,000122: 23,3336 14025 STODL THETA # X = ARCSIN(SIN) WITH SIGN(SIN)
053597,000123: 23,3337 00021 COSTH
053598,000124: 23,3340 77640 BMN
053599,000125: 23,3341 47344 TRIG2 # IF (135,-135)
053600,000126:
053601,000127: 23,3342 43545 DLOAD RVQ
053602,000128: 23,3343 00025 THETA # X = ARCSIN(SIN) (-45,45)
053603,000129:
053604,000130: 23,3344 75345 TRIG2 DLOAD SIGN # (135,-135)
053605,000131: 23,3345 06520 HIDPHALF
053606,000132: 23,3346 00023 SINTH
053607,000133: 23,3347 77625 DSU
053608,000134: 23,3350 00025 THETA
053609,000135: 23,3351 00025 STORE THETA # X = .5 WITH SIGN(SIN) - ARCSIN(SIN)
053610,000136: 23,3352 77616 RVQ # (+) - (+) OR (-) - (-)
053611,000137:
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Page 1252 |
053613,000139: # SMNB, NBSM, AND AXISROT, WHICH USED TO APPEAR HERE, HAVE BEEN
053614,000140: # COMBINED IN A ROUTINE CALLED AX*SR*T, WHICH APPEARS AMONG THE POWERED
053615,000141: # FLIGHT SUBROUTINES.
053616,000142:
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Page 1253 |
053618,000144: # CALCGA COMPUTES THE CDU DRIVING ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
053619,000145:
053620,000146: # THE INPUTS ARE 1) THE NAVIGATION BASE COORDINATES REFERRED TO ANY COORDINATE SYSTEM. THE THREE HALF-UNIT
053621,000147: # VECTORS ARE STORED AT XNB, YNB, AND ZNB. 2) THE DESIRED STABLE MEMBER COORDINATES REFERRED TO THE SAME
053622,000148: # COORDINATE SYSTEM ARE STORED AT XSM, YSM, AND ZSM.
053623,000149:
053624,000150: # THE OUTPUTS ARE THE THREE CDU DRIVING ANGLES AND ARE STORED SP AT THETAD, THETAD +1, AND THETAD +2.
053625,000151:
053626,000152: 23,3353 77601 CALCGA SETPD # PUSHDOWN 00-05, 16D-21D, 34D-37D
053627,000153: 23,3354 00001 0
053628,000154: 23,3355 47375 VLOAD VXV
053629,000155: 23,3356 02665 XNB # XNB = OGA (OUTER GIMBAL AXIS)
053630,000156: 23,3357 02651 YSM # YSM = IGA (INNER GIMBAL AXIS)
053631,000157: 23,3360 41456 UNIT PUSH # PD0 = UNIT(OGA X IGA) = MGA
053632,000158:
053633,000159: 23,3361 44041 DOT ITA
053634,000160: 23,3362 02701 ZNB
053635,000161: 23,3363 00051 S2
053636,000162: 23,3364 24021 STOVL COSTH # COS(OG) = MGA . ZNB
053637,000163: 23,3365 00001 0
053638,000164: 23,3366 77641 DOT
053639,000165: 23,3367 02673 YNB
053640,000166: 23,3370 34023 STCALL SINTH # SIN(OG) = MGA . YNB
053641,000167: 23,3371 47320 ARCTRIG
053642,000168: 23,3372 26740 STOVL OGC
053643,000169: 23,3373 00001 0
053644,000170:
053645,000171: 23,3374 50235 VXV DOT # PROVISION FOR MG ANGLE OF 90 DEGREES
053646,000172: 23,3375 02665 XNB
053647,000173: 23,3376 02651 YSM
053648,000174: 23,3377 77752 SL1
053649,000175: 23,3400 24021 STOVL COSTH # COS(MG) = IGA . (MGA X OGA)
053650,000176: 23,3401 02651 YSM
053651,000177: 23,3402 77641 DOT
053652,000178: 23,3403 02665 XNB
053653,000179: 23,3404 34023 STCALL SINTH # SIN(MG) = IGA . OGA
053654,000180: 23,3405 47320 ARCTRIG
053655,000181: 23,3406 02744 STORE MGC
053656,000182:
053657,000183: 23,3407 45246 ABS DSU
053658,000184: 23,3410 07536 .166...
053659,000185: 23,3411 77644 BPL
053660,000186: 23,3412 47431 GIMLOCK1 # IF ANGLE GREATER THAN 60 DEGREES
053661,000187:
053662,000188: 23,3413 50375 CALCGA1 VLOAD DOT
053663,000189: 23,3414 02657 ZSM
053664,000190: 23,3415 00001 0
053665,000191: 23,3416 24021 STOVL COSTH # COS(IG) = ZSM . MGA
053666,000192: 23,3417 02643 XSM
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Page 1254 |
053668,000194: 23,3420 45441 DOT STADR
053669,000195: 23,3421 43754 STCALL SINTH # SIN(IG) = XSM . MGA
053670,000196: 23,3422 47320 ARCTRIG
053671,000197:
053672,000198: 23,3423 26742 STOVL IGC
053673,000199: 23,3424 02740 OGC
053674,000200: 23,3425 77634 RTB
053675,000201: 23,3426 21620 V1STO2S
053676,000202: 23,3427 34322 STCALL THETAD
053677,000203: 23,3430 00051 S2
053678,000204:
053679,000205: 23,3431 77776 GIMLOCK1 EXIT
053680,000206: 23,3432 05567 TC ALARM
053681,000207: 23,3433 00401 OCT 00401
053682,000208: 23,3434 05504 TC UPFLAG # GIMBAL LOCK HAS OCCURED
053683,000209: 23,3435 00056 ADRES GLOKFAIL
053684,000210:
053685,000211: 23,3436 06037 TC INTPRET
053686,000212: 23,3437 77650 GOTO
053687,000213: 23,3440 47413 CALCGA1
053688,000214:
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Page 1255 |
053690,000216: # AXISGEN COMPUTES THE COORDINATES OF ONE COORDINATE SYSTEM REFERRED TO ANOTHER COORDINATE SYSTEM.
053691,000217:
053692,000218: # THE INPUTS ARE 1) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM A STORED AT STARAD. 2) THE STAR2 VECTOR
053693,000219: # REFERRED TO COORDINATE SYSTEM A STORED AT STARAD +6. 3) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM B STORED
053694,000220: # AT LOCATION 6 OF THE VAC AREA. 4) THE STAR2 VECTOR REFERRED TO COORDINATE SYSTEM B STORED AT LOCATION 12D OF
053695,000221: # THE VAC AREA.
053696,000222:
053697,000223: # THE OUTPUT DEFINES COORDINATE SYSTEM A REFERRED TO COORDINATE SYSTEM B. THE THREE HALF-UNIT VECTORS ARE STORED
053698,000224: # AT LOCATIONS XDC, XDC +6, XDC +12D, AND STARAD, STARAD +6, STARAD +12D.
053699,000225:
053700,000226: 23,3441 66370 AXISGEN AXT,1 SSP # PUSHDOWN 00-30D, 34D-37D
053701,000227: 23,3442 02714 STARAD +6
053702,000228: 23,3443 00051 S1
053703,000229: 23,3444 02700 STARAD -6
053704,000230:
053705,000231: 23,3445 77601 SETPD
053706,000232: 23,3446 00001 0
053707,000233: 23,3447 46773 AXISGEN1 VLOAD* VXV* # 06D UA = S1
053708,000234: 23,3450 02723 STARAD +12D,1 # STARAD +00D UB = S1
053709,000235: 23,3451 02731 STARAD +18D,1
053710,000236: 23,3452 77656 UNIT # 12D VA = UNIT(S1 X S2)
053711,000237: 23,3453 06731 STORE STARAD +18D,1 # STARAD +06D VB = UNIT(S1 X S2)
053712,000238: 23,3454 77773 VLOAD*
053713,000239: 23,3455 02723 STARAD +12D,1
053714,000240:
053715,000241: 23,3456 76433 VXV* VSL1
053716,000242: 23,3457 02731 STARAD +18D,1 # 18D WA = UA X VA
053717,000243: 23,3460 06737 STORE STARAD +24D,1 # STARAD +12D WB = UB X VB
053718,000244:
053719,000245: 23,3461 77700 TIX,1
053720,000246: 23,3462 47447 AXISGEN1
053721,000247:
053722,000248: 23,3463 66160 AXC,1 SXA,1
053723,000249: 23,3464 00006 6
053724,000250: 23,3465 00036 30D
053725,000251:
053726,000252: 23,3466 66370 AXT,1 SSP
053727,000253: 23,3467 00022 18D
053728,000254: 23,3470 00051 S1
053729,000255: 23,3471 00006 6
053730,000256:
053731,000257: 23,3472 66374 AXT,2 SSP
053732,000258: 23,3473 00006 6
053733,000259: 23,3474 00052 S2
053734,000260: 23,3475 00002 2
053735,000261:
053736,000262: 23,3476 76720 AXISGEN2 XCHX,1 VLOAD*
053737,000263: 23,3477 00036 30D # X1=-6 X2=+6 X1=-6 X2=+4 X1=-6 X2=+2
053738,000264: 23,3500 00001 0,1
053739,000265:
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Page 1256 |
053741,000267: 23,3501 62757 VXSC* PDVL* # J=(UA)(UB1) J=(UA)(UB2) J=(UA)(UB3)
053742,000268: 23,3502 75062 STARAD +6,2
053743,000269: 23,3503 00007 6,1
053744,000270: 23,3504 77757 VXSC*
053745,000271: 23,3505 75054 STARAD +12D,2
053746,000272: 23,3506 30031 STOVL* 24D # K=(VA)(VB1) J=(VA)(VB2) J=(VA)(VB3)
053747,000273: 23,3507 00015 12D,1
053748,000274:
053749,000275: 23,3510 53357 VXSC* VAD
053750,000276: 23,3511 75046 STARAD +18D,2 # L=(WA)(WB1) J=(WA)(WB2) J=(WA)(WB3)
053751,000277: 23,3512 76455 VAD VSL1
053752,000278: 23,3513 00031 24D
053753,000279: 23,3514 53520 XCHX,1 UNIT
053754,000280: 23,3515 00036 30D
053755,000281: 23,3516 06707 STORE XDC +18D,1 # XDC = L+J+K YDC = L+J+K ZDC = L+J+K
053756,000282:
053757,000283: 23,3517 77700 TIX,1
053758,000284: 23,3520 47521 AXISGEN3
053759,000285:
053760,000286: 23,3521 77704 AXISGEN3 TIX,2
053761,000287: 23,3522 47476 AXISGEN2
053762,000288:
053763,000289: 23,3523 77775 VLOAD
053764,000290: 23,3524 02665 XDC
053765,000291: 23,3525 26707 STOVL STARAD
053766,000292: 23,3526 02673 YDC
053767,000293: 23,3527 26715 STOVL STARAD +6
053768,000294: 23,3530 02701 ZDC
053769,000295: 23,3531 02723 STORE STARAD +12D
053770,000296:
053771,000297: 23,3532 77616 RVQ
053772,000298:
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Page 1257 |
053774,000300: 23,3533 05520 26075 QTSN45 2DEC .1768
053775,000301:
053776,000302: 23,3535 05252 25253 .166... 2DEC .1666666667
053777,000303:
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Page 1258 Empty page |
053780,000306:
End of include-file INFLIGHT_ALIGNMENT_ROUTINES.agc. Parent file is MAIN.agc