Source Code

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. 28,1968
Note 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: 

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                               

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: 

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: 

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: 

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                                   

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: 

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: 

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: 

Page 1257

053774,000300: 23,3533           05520 26075  QTSN45             2DEC     .1768                                 
053775,000301: 
053776,000302: 23,3535           05252 25253  .166...            2DEC     .1666666667                            
053777,000303: 

Page 1258 Empty page

053780,000306: 

End of include-file INFLIGHT_ALIGNMENT_ROUTINES.agc.  Parent file is MAIN.agc