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. |
053497,000002: ## Copyright: Public domain.
053498,000003: ## Filename: INFLIGHT_ALIGNMENT_ROUTINES.agc
053499,000004: ## Purpose: Part of the source code for Luminary 1A build 099.
053500,000005: ## It is part of the source code for the Lunar Module's (LM)
053501,000006: ## Apollo Guidance Computer (AGC), for Apollo 11.
053502,000007: ## Assembler: yaYUL
053503,000008: ## Contact: Ron Burkey <info@sandroid.org>.
053504,000009: ## Website: www.ibiblio.org/apollo.
053505,000010: ## Pages: 1249-1258
053506,000011: ## Mod history: 2009-05-26 RSB Adapted from the corresponding
053507,000012: ## Luminary131 file, using page
053508,000013: ## images from Luminary 1A.
053509,000014: ## 2016-12-17 RSB Proofed text comments with octopus/ProoferComments
053510,000015: ## and corrected the errors found.
053511,000016: ## 2017-03-17 RSB Comment-text fixes identified in diff'ing
053512,000017: ## Luminary 99 vs Comanche 55.
053513,000018:
053514,000019: ## This source code has been transcribed or otherwise adapted from
053515,000020: ## digitized images of a hardcopy from the MIT Museum. The digitization
053516,000021: ## was performed by Paul Fjeld, and arranged for by Deborah Douglas of
053517,000022: ## the Museum. Many thanks to both. The images (with suitable reduction
053518,000023: ## in storage size and consequent reduction in image quality as well) are
053519,000024: ## available online at www.ibiblio.org/apollo. If for some reason you
053520,000025: ## find that the images are illegible, contact me at info@sandroid.org
053521,000026: ## about getting access to the (much) higher-quality images which Paul
053522,000027: ## actually created.
053523,000028: ##
053524,000029: ## Notations on the hardcopy document read, in part:
053525,000030: ##
053526,000031: ## Assemble revision 001 of AGC program LMY99 by NASA 2021112-61
053527,000032: ## 16:27 JULY 14, 1969
053528,000033:
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Page 1249 |
053530,000035: 22,3773 BANK 22
053531,000036: 23,2000 SETLOC INFLIGHT
053532,000037: 23,2000 BANK
053533,000038:
053534,000039: 23,3247 E5,1642 EBANK= XSM
053535,000040:
053536,000041: # CALCGTA COMPUTES THE GYRO TORQUE ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
053537,000042:
053538,000043: # THE INPUT IS THE DESIRED STABLE MEMBER COORDINATES REFERRED TO PRESENT STABLE MEMBER COORDINATES. THE THREE
053539,000044: # HALF-UNIT VECTORS ARE STORED AT XDC, YDC, AND ZDC.
053540,000045:
053541,000046: # THE OUTPUTS ARE THE THREE GYRO TORQUING ANGLES TO BE APPLIED TO THE Y, Z, AND X GYROS AND ARE STORED DP AT IGC,
053542,000047: # MGC, AND OGC RESPECTIVELY.
053543,000048:
053544,000049: 23,3247 COUNT* $$/INFLT
053545,000050: 23,3247 71220 CALCGTA ITA DLOAD # PUSHDOWN 00-03, 16D-27D, 34D-37D
053546,000051: 23,3250 00051 S2 # XDC = (XD1 XD2 XD3)
053547,000052: 23,3251 02665 XDC # YDC = (YD1 YD2 YD3)
053548,000053: 23,3252 65325 PDDL PDDL # ZDC = (ZD1 ZD2 ZD3)
053549,000054: 23,3253 06522 HI6ZEROS
053550,000055: 23,3254 02671 XDC +4
053551,000056: 23,3255 55476 DCOMP VDEF
053552,000057: 23,3256 77656 UNIT
053553,000058: 23,3257 14027 STODL ZPRIME # ZP = UNIT(-XD3 0 XD1) = (ZP1 ZP2 ZP3)
053554,000059: 23,3260 00027 ZPRIME
053555,000060:
053556,000061: 23,3261 77742 SR1
053557,000062: 23,3262 14023 STODL SINTH # SIN(IGC) = ZP1
053558,000063: 23,3263 00033 ZPRIME +4
053559,000064: 23,3264 77742 SR1
053560,000065: 23,3265 34021 STCALL COSTH # COS(IGC) = ZP3
053561,000066: 23,3266 47320 ARCTRIG
053562,000067:
053563,000068: 23,3267 16742 STODL IGC # Y GYRO TORQUING ANGLE FRACTION OF REV.
053564,000069: 23,3270 02667 XDC +2
053565,000070: 23,3271 77742 SR1
053566,000071: 23,3272 14023 STODL SINTH # SIN(MGC) = XD2
053567,000072: 23,3273 00027 ZPRIME
053568,000073:
053569,000074: 23,3274 65205 DMP PDDL
053570,000075: 23,3275 02671 XDC +4 # PD00 = (ZP1)(XD3)
053571,000076: 23,3276 00033 ZPRIME +4
053572,000077:
053573,000078: 23,3277 45205 DMP DSU
053574,000079: 23,3300 02665 XDC # MPAC = (ZP3)(XD1)
053575,000080: 23,3301 77626 STADR
053576,000081: 23,3302 43756 STCALL COSTH # COS(MGC) = MPAC - PD00
053577,000082: 23,3303 47320 ARCTRIG
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Page 1250 |
053579,000084: 23,3304 26744 STOVL MGC # Z GYRO TORQUING ANGLE FRACTION OF REV.
053580,000085: 23,3305 00027 ZPRIME
053581,000086: 23,3306 77641 DOT
053582,000087: 23,3307 02701 ZDC
053583,000088: 23,3310 24021 STOVL COSTH # COS(OGC) = ZP . ZDC
053584,000089: 23,3311 00027 ZPRIME
053585,000090: 23,3312 77641 DOT
053586,000091: 23,3313 02673 YDC
053587,000092: 23,3314 34023 STCALL SINTH # SIN(OGC) = ZP . YDC
053588,000093: 23,3315 47320 ARCTRIG
053589,000094:
053590,000095: 23,3316 36740 STCALL OGC # X GYRO TORQUING ANGLE FRACTION OF REV.
053591,000096: 23,3317 00051 S2
053592,000097:
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Page 1251 |
053594,000099: # ARCTRIG COMPUTES AN ANGLE GIVEN THE SINE AND COSINE OF THIS ANGLE.
053595,000100:
053596,000101: # THE INPUTS ARE SIN/4 AND COS/4 STORED DP AT SINTH AND COSTH.
053597,000102:
053598,000103: # THE OUTPUT IS THE CALCULATED ANGLE BETWEEN +.5 AND -.5 REVOLUTIONS AND STORED AT THETA. THE OUTPUT IS ALSO
053599,000104: # AVAILABLE AT MPAC.
053600,000105:
053601,000106: 23,3320 51545 ARCTRIG DLOAD ABS # PUSHDOWN 16D-21D
053602,000107: 23,3321 00023 SINTH
053603,000108: 23,3322 50025 DSU BMN
053604,000109: 23,3323 07534 QTSN45 # ABS(SIN/4) - SIN(45)/4
053605,000110: 23,3324 47333 TRIG1 # IF (-45,45) OR (135,-135)
053606,000111:
053607,000112: 23,3325 72545 DLOAD SL1 # (45,135) OR (-135,-45)
053608,000113: 23,3326 00021 COSTH
053609,000114: 23,3327 75326 ACOS SIGN
053610,000115: 23,3330 00023 SINTH
053611,000116: 23,3331 00025 STORE THETA # X = ARCCOS(COS) WITH SIGN(SIN)
053612,000117: 23,3332 77616 RVQ
053613,000118:
053614,000119: 23,3333 72545 TRIG1 DLOAD SL1 # (-45,45) OR (135,-135)
053615,000120: 23,3334 00023 SINTH
053616,000121: 23,3335 77736 ASIN
053617,000122: 23,3336 14025 STODL THETA # X = ARCSIN(SIN) WITH SIGN(SIN)
053618,000123: 23,3337 00021 COSTH
053619,000124: 23,3340 77640 BMN
053620,000125: 23,3341 47344 TRIG2 # IF (135,-135)
053621,000126:
053622,000127: 23,3342 43545 DLOAD RVQ
053623,000128: 23,3343 00025 THETA # X = ARCSIN(SIN) (-45,45)
053624,000129:
053625,000130: 23,3344 75345 TRIG2 DLOAD SIGN # (135,-135)
053626,000131: 23,3345 06520 HIDPHALF
053627,000132: 23,3346 00023 SINTH
053628,000133: 23,3347 77625 DSU
053629,000134: 23,3350 00025 THETA
053630,000135: 23,3351 00025 STORE THETA # X = .5 WITH SIGN(SIN) - ARCSIN(SIN)
053631,000136: 23,3352 77616 RVQ # (+) - (+) OR (-) - (-)
053632,000137:
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Page 1252 |
053634,000139: # SMNB, NBSM, AND AXISROT, WHICH USED TO APPEAR HERE, HAVE BEEN
053635,000140: # COMBINED IN A ROUTINE CALLED AX*SR*T, WHICH APPEARS AMONG THE POWERED
053636,000141: # FLIGHT SUBROUTINES.
053637,000142:
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Page 1253 |
053639,000144: # CALCGA COMPUTES THE CDU DRIVING ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
053640,000145:
053641,000146: # THE INPUTS ARE 1) THE NAVIGATION BASE COORDINATES REFERRED TO ANY COORDINATE SYSTEM. THE THREE HALF-UNIT
053642,000147: # VECTORS ARE STORED AT XNB, YNB, AND ZNB. 2) THE DESIRED STABLE MEMBER COORDINATES REFERRED TO THE SAME
053643,000148: # COORDINATE SYSTEM ARE STORED AT XSM, YSM, AND ZSM.
053644,000149:
053645,000150: # THE OUTPUTS ARE THE THREE CDU DRIVING ANGLES AND ARE STORED SP AT THETAD, THETAD +1, AND THETAD +2.
053646,000151:
053647,000152: 23,3353 77601 CALCGA SETPD # PUSHDOWN 00-05, 16D-21D, 34D-37D
053648,000153: 23,3354 00001 0
053649,000154: 23,3355 47375 VLOAD VXV
053650,000155: 23,3356 02665 XNB # XNB = OGA (OUTER GIMBAL AXIS)
053651,000156: 23,3357 02651 YSM # YSM = IGA (INNER GIMBAL AXIS)
053652,000157: 23,3360 41456 UNIT PUSH # PD0 = UNIT(OGA X IGA) = MGA
053653,000158:
053654,000159: 23,3361 44041 DOT ITA
053655,000160: 23,3362 02701 ZNB
053656,000161: 23,3363 00051 S2
053657,000162: 23,3364 24021 STOVL COSTH # COS(OG) = MGA . ZNB
053658,000163: 23,3365 00001 0
053659,000164: 23,3366 77641 DOT
053660,000165: 23,3367 02673 YNB
053661,000166: 23,3370 34023 STCALL SINTH # SIN(OG) = MGA . YNB
053662,000167: 23,3371 47320 ARCTRIG
053663,000168: 23,3372 26740 STOVL OGC
053664,000169: 23,3373 00001 0
053665,000170:
053666,000171: 23,3374 50235 VXV DOT # PROVISION FOR MG ANGLE OF 90 DEGREES
053667,000172: 23,3375 02665 XNB
053668,000173: 23,3376 02651 YSM
053669,000174: 23,3377 77752 SL1
053670,000175: 23,3400 24021 STOVL COSTH # COS(MG) = IGA . (MGA X OGA)
053671,000176: 23,3401 02651 YSM
053672,000177: 23,3402 77641 DOT
053673,000178: 23,3403 02665 XNB
053674,000179: 23,3404 34023 STCALL SINTH # SIN(MG) = IGA . OGA
053675,000180: 23,3405 47320 ARCTRIG
053676,000181: 23,3406 02744 STORE MGC
053677,000182:
053678,000183: 23,3407 45246 ABS DSU
053679,000184: 23,3410 07536 .166...
053680,000185: 23,3411 77644 BPL
053681,000186: 23,3412 47431 GIMLOCK1 # IF ANGLE GREATER THAN 60 DEGREES
053682,000187:
053683,000188: 23,3413 50375 CALCGA1 VLOAD DOT
053684,000189: 23,3414 02657 ZSM
053685,000190: 23,3415 00001 0
053686,000191: 23,3416 24021 STOVL COSTH # COS(IG) = ZSM . MGA
053687,000192: 23,3417 02643 XSM
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Page 1254 |
053689,000194: 23,3420 45441 DOT STADR
053690,000195: 23,3421 43754 STCALL SINTH # SIN(IG) = XSM . MGA
053691,000196: 23,3422 47320 ARCTRIG
053692,000197:
053693,000198: 23,3423 26742 STOVL IGC
053694,000199: 23,3424 02740 OGC
053695,000200: 23,3425 77634 RTB
053696,000201: 23,3426 21620 V1STO2S
053697,000202: 23,3427 34322 STCALL THETAD
053698,000203: 23,3430 00051 S2
053699,000204:
053700,000205: 23,3431 77776 GIMLOCK1 EXIT
053701,000206: 23,3432 05567 TC ALARM
053702,000207: 23,3433 00401 OCT 00401
053703,000208: 23,3434 05504 TC UPFLAG # GIMBAL LOCK HAS OCCURED
053704,000209: 23,3435 00056 ADRES GLOKFAIL
053705,000210:
053706,000211: 23,3436 06037 TC INTPRET
053707,000212: 23,3437 77650 GOTO
053708,000213: 23,3440 47413 CALCGA1
053709,000214:
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Page 1255 |
053711,000216: # AXISGEN COMPUTES THE COORDINATES OF ONE COORDINATE SYSTEM REFERRED TO ANOTHER COORDINATE SYSTEM.
053712,000217:
053713,000218: # THE INPUTS ARE 1) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM A STORED AT STARAD. 2) THE STAR2 VECTOR
053714,000219: # REFERRED TO COORDINATE SYSTEM A STORED AT STARAD +6. 3) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM B STORED
053715,000220: # AT LOCATION 6 OF THE VAC AREA. 4) THE STAR2 VECTOR REFERRED TO COORDINATE SYSTEM B STORED AT LOCATION 12D OF
053716,000221: # THE VAC AREA.
053717,000222:
053718,000223: # THE OUTPUT DEFINES COORDINATE SYSTEM A REFERRED TO COORDINATE SYSTEM B. THE THREE HALF-UNIT VECTORS ARE STORED
053719,000224: # AT LOCATIONS XDC, XDC +6, XDC +12D, AND STARAD, STARAD +6, STARAD +12D.
053720,000225:
053721,000226: 23,3441 66370 AXISGEN AXT,1 SSP # PUSHDOWN 00-30D, 34D-37D
053722,000227: 23,3442 02714 STARAD +6
053723,000228: 23,3443 00051 S1
053724,000229: 23,3444 02700 STARAD -6
053725,000230:
053726,000231: 23,3445 77601 SETPD
053727,000232: 23,3446 00001 0
053728,000233: 23,3447 46773 AXISGEN1 VLOAD* VXV* # 06D UA = S1
053729,000234: 23,3450 02723 STARAD +12D,1 # STARAD +00D UB = S1
053730,000235: 23,3451 02731 STARAD +18D,1
053731,000236: 23,3452 77656 UNIT # 12D VA = UNIT(S1 X S2)
053732,000237: 23,3453 06731 STORE STARAD +18D,1 # STARAD +06D VB = UNIT(S1 X S2)
053733,000238: 23,3454 77773 VLOAD*
053734,000239: 23,3455 02723 STARAD +12D,1
053735,000240:
053736,000241: 23,3456 76433 VXV* VSL1
053737,000242: 23,3457 02731 STARAD +18D,1 # 18D WA = UA X VA
053738,000243: 23,3460 06737 STORE STARAD +24D,1 # STARAD +12D WB = UB X VB
053739,000244:
053740,000245: 23,3461 77700 TIX,1
053741,000246: 23,3462 47447 AXISGEN1
053742,000247:
053743,000248: 23,3463 66160 AXC,1 SXA,1
053744,000249: 23,3464 00006 6
053745,000250: 23,3465 00036 30D
053746,000251:
053747,000252: 23,3466 66370 AXT,1 SSP
053748,000253: 23,3467 00022 18D
053749,000254: 23,3470 00051 S1
053750,000255: 23,3471 00006 6
053751,000256:
053752,000257: 23,3472 66374 AXT,2 SSP
053753,000258: 23,3473 00006 6
053754,000259: 23,3474 00052 S2
053755,000260: 23,3475 00002 2
053756,000261:
053757,000262: 23,3476 76720 AXISGEN2 XCHX,1 VLOAD*
053758,000263: 23,3477 00036 30D # X1=-6 X2=+6 X1=-6 X2=+4 X1=-6 X2=+2
053759,000264: 23,3500 00001 0,1
053760,000265:
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Page 1256 |
053762,000267: 23,3501 62757 VXSC* PDVL* # J=(UA)(UB1) J=(UA)(UB2) J=(UA)(UB3)
053763,000268: 23,3502 75062 STARAD +6,2
053764,000269: 23,3503 00007 6,1
053765,000270: 23,3504 77757 VXSC*
053766,000271: 23,3505 75054 STARAD +12D,2
053767,000272: 23,3506 30031 STOVL* 24D # K=(VA)(VB1) J=(VA)(VB2) J=(VA)(VB3)
053768,000273: 23,3507 00015 12D,1
053769,000274:
053770,000275: 23,3510 53357 VXSC* VAD
053771,000276: 23,3511 75046 STARAD +18D,2 # L=(WA)(WB1) J=(WA)(WB2) J=(WA)(WB3)
053772,000277: 23,3512 76455 VAD VSL1
053773,000278: 23,3513 00031 24D
053774,000279: 23,3514 53520 XCHX,1 UNIT
053775,000280: 23,3515 00036 30D
053776,000281: 23,3516 06707 STORE XDC +18D,1 # XDC = L+J+K YDC = L+J+K ZDC = L+J+K
053777,000282:
053778,000283: 23,3517 77700 TIX,1
053779,000284: 23,3520 47521 AXISGEN3
053780,000285:
053781,000286: 23,3521 77704 AXISGEN3 TIX,2
053782,000287: 23,3522 47476 AXISGEN2
053783,000288:
053784,000289: 23,3523 77775 VLOAD
053785,000290: 23,3524 02665 XDC
053786,000291: 23,3525 26707 STOVL STARAD
053787,000292: 23,3526 02673 YDC
053788,000293: 23,3527 26715 STOVL STARAD +6
053789,000294: 23,3530 02701 ZDC
053790,000295: 23,3531 02723 STORE STARAD +12D
053791,000296:
053792,000297: 23,3532 77616 RVQ
053793,000298:
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Page 1257 |
053795,000300: 23,3533 05520 26075 QTSN45 2DEC .1768
053796,000301:
053797,000302: 23,3535 05252 25253 .166... 2DEC .1666666667
053798,000303:
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Page 1258 Empty page |
053801,000306:
End of include-file INFLIGHT_ALIGNMENT_ROUTINES.agc. Parent file is MAIN.agc