Source Code

This is a reconstruction of the AGC program Luminary 99 Rev 0. It was the second release of the Lunar Module flight software targeted for use in Apollo 11, after Luminary 97. A bug (which had been around since at least Apollo 10, Luminary 69) was discovered in Rev 0 shortly before the Apollo 11 flight, resulting in a last minute revision into Rev 1, which is what actually flew rather than the Rev 0 presented here. A hardcopy of Rev 0 is known to exist — it belonged to AGC developer Allan Klumpp for many years — but unfortunately the Virtual AGC Project has not had access to that hardcopy. Thus the code you see here had been reconstructed (we believe accurately) rather than transcribed. The first step of the reconstruction of the Rev 0 source code was the transcription of the Rev 1 source code from a hardcopy in the MIT Museum collection. The process of reverting the active portion of the source code (i.e., other than program comments) from Rev 1 to Rev 0 was very minor, consisting only of moving the position of the STARTSB1 label in FRESH START AND RESTART. Allan had previously given us the checksums of the memory banks of Rev 0, and we have verified the program presented here has checksums identical to all banks of Allan's listing of Rev 0. The notations on Allan's Rev 0 program listing read, in part:

	GAP:  ASSEMBLE REVISION 099 OF AGC PROGRAM LUMINARY BY NASA 2021112-051

A single program comment is known to differ between Rev 0 and Rev 1, but these are harder to reconstruct and verify than changes to the active portion of the code. Thus it is possible that there are additional differences between the program comments in Rev 0 and Rev 1 that are unknown to us, and therefore are not reflected in the code presented here.

015649,000002:                                                                                                  ## Copyright:   Public domain.
015650,000003:                                                                                                  ## Filename:    KALCMANU_STEERING.agc
015651,000004:                                                                                                  ## Purpose:     Part of the reconstructed source code for LMY99 Rev 0,
015652,000005:                                                                                                  ##              otherwise known as Luminary Rev 99, the second release
015653,000006:                                                                                                  ##              of the Apollo Guidance Computer (AGC) software for Apollo 11.
015654,000007:                                                                                                  ##              It differs from LMY99 Rev 1 (the flown version) only in the
015655,000008:                                                                                                  ##              placement of a single label. The corrections shown here have
015656,000009:                                                                                                  ##              been verified to have the same bank checksums as AGC developer
015657,000010:                                                                                                  ##              Allan Klumpp's copy of Luminary Rev 99, and so are believed
015658,000011:                                                                                                  ##              to be accurate. This file is intended to be a faithful 
015659,000012:                                                                                                  ##              recreation, except that the code format has been changed to 
015660,000013:                                                                                                  ##              conform to the requirements of the yaYUL assembler rather than 
015661,000014:                                                                                                  ##              the original YUL assembler.
015662,000015:                                                                                                  ##
015663,000016:                                                                                                  ## Assembler:   yaYUL
015664,000017:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
015665,000018:                                                                                                  ## Website:     www.ibiblio.org/apollo.
015666,000019:                                                                                                  ## Pages:       365-369
015667,000020:                                                                                                  ## Mod history: 2009-05-17 RSB  Adapted from the corresponding 
015668,000021:                                                                                                  ##                              Luminary131 file, using page 
015669,000022:                                                                                                  ##                              images from Luminary 1A.
015670,000023:                                                                                                  ##              2011-01-06 JL   Added missing comment characters.
015671,000024:                                                                                                  ##              2016-12-14 RSB  Proofed text comments with octopus/ProoferComments
015672,000025:                                                                                                  ##                              and corrected the errors found.
015673,000026:                                                                                                  ##              2017-03-07 RSB  Removed yaYUL workaround that no longer 
015674,000027:                                                                                                  ##                              seems to be needed.
015675,000028:                                                                                                  ##              2017-03-17 RSB  Comment-text fixes identified in diff'ing
015676,000029:                                                                                                  ##                              Luminary 99 vs Comanche 55.
015677,000030:                                                                                                  ##              2017-08-01 MAS  Created from LMY99 Rev 1.
015678,000031: 
015679,000032:                                                                                                  ## This source code has been transcribed or otherwise adapted from
015680,000033:                                                                                                  ## digitized images of a hardcopy from the MIT Museum.  The digitization
015681,000034:                                                                                                  ## was performed by Paul Fjeld, and arranged for by Deborah Douglas of
015682,000035:                                                                                                  ## the Museum.  Many thanks to both.  The images (with suitable reduction
015683,000036:                                                                                                  ## in storage size and consequent reduction in image quality as well) are
015684,000037:                                                                                                  ## available online at www.ibiblio.org/apollo.  If for some reason you
015685,000038:                                                                                                  ## find that the images are illegible, contact me at info@sandroid.org
015686,000039:                                                                                                  ## about getting access to the (much) higher-quality images which Paul
015687,000040:                                                                                                  ## actually created.
015688,000041:                                                                                                  ##
015689,000042:                                                                                                  ## The code has been modified to match LMY99 Revision 0, otherwise
015690,000043:                                                                                                  ## known as Luminary Revision 99, the Apollo 11 software release preceeding
015691,000044:                                                                                                  ## the listing from which it was transcribed. It has been verified to
015692,000045:                                                                                                  ## contain the same bank checksums as AGC developer Allan Klumpp's listing
015693,000046:                                                                                                  ## of Luminary Revision 99 (for which we do not have scans).
015694,000047:                                                                                                  ##
015695,000048:                                                                                                  ## Notations on Allan Klumpp's listing read, in part:
015696,000049:                                                                                                  ##
015697,000050:                                                                                                  ##      ASSEMBLE REVISION 099 OF AGC PROGRAM LUMINARY BY NASA 2021112-51
015698,000051: 

Page 365

015700,000053:                                                                                                  #  GENERATION OF STEERING COMMANDS FOR DIGITAL AUTOPILOT FREE FALL MANEUVERS
015701,000054: 
015702,000055:                                                                                                  #  NEW COMMANDS WILL BE GENERATED EVERY ONE SECOND DURING THE MANEUVER
015703,000056: 
015704,000057: 22,3003  E6,1707                                  EBANK=   TTEMP                                 
015705,000058: 
015706,000059: 22,3003           04616        NEWDELHI           TC       BANKCALL                              #  CHECK FOR AUTO STABILIZATION
015707,000060: 22,3004           54262                           CADR     ISITAUTO                              #  ONLY
015708,000061: 22,3005           10000                           CCS      A                                     
015709,000062: 22,3006           12730                           TCF      NOGO       -2                         
015710,000063: 22,3007           06037        NEWANGL            TC       INTPRET                               
015711,000064: 22,3010           75160                           AXC,1    AXC,2                                 
015712,000065: 22,3011           03246                                    MIS                                   #  COMPUTE THE NEW MATRIX FROM S/C TO
015713,000066: 22,3012           02230                                    KEL                                   #  STABLE MEMBER AXES
015714,000067: 22,3013           77624                           CALL                                           
015715,000068: 22,3014           44312                                    MXM3                                  
015716,000069: 22,3015           45575                           VLOAD    STADR                                 
015717,000070: 22,3016           50514                           STOVL    MIS        +12D                       #  CALCULATE NEW DESIRED CDU ANGLES
015718,000071: 22,3017           77626                           STADR                                          
015719,000072: 22,3020           50522                           STOVL    MIS        +6D                        
015720,000073: 22,3021           77626                           STADR                                          
015721,000074: 22,3022           74530                           STORE    MIS                                   
015722,000075: 22,3023           45160                           AXC,1    CALL                                  
015723,000076: 22,3024           03246                                    MIS                                   
015724,000077: 22,3025           44654                                    DCMTOCDU                              #  PICK UP THE NEW CDU ANGLES FROM MATRIX
015725,000078: 22,3026           77634                           RTB                                            
015726,000079: 22,3027           21620                                    V1STO2S                               
015727,000080: 22,3030           03304                           STORE    NCDU                                  #  NEW CDU ANGLES
015728,000081: 22,3031           77414                           BONCLR   EXIT                                  
015729,000082: 22,3032           01215                                    CALCMAN2                              
015730,000083: 22,3033           45122                                    MANUSTAT                              #  TO START MANEUVER
015731,000084: 22,3034           34752                           CAF      TWO                                   #        +0 OTHERWISE
015732,000085: 22,3035           55272        INCRDCDU           TS       SPNDX                                 
015733,000086: 22,3036           51272                           INDEX    SPNDX                                 
015734,000087: 22,3037           31676                           CA       BCDU                                  #  INITIAL CDU ANGLES
015735,000088: 22,3040           00006                           EXTEND                                         #  OR PREVIOUS DESIRED CDU ANGLES
015736,000089: 22,3041           51272                           INDEX    SPNDX                                 
015737,000090: 22,3042           21703                           MSU      NCDU                                  
015738,000091: 22,3043           00006                           EXTEND                                         
015739,000092: 22,2000                                           SETLOC   KALCMON1                              
015740,000093: 22,2000                                           BANK                                           
015741,000094: 
015742,000095: 22,3044           73121                           MP       DT/TAU                                
015743,000096: 22,3045           10000                           CCS      A                                     #  CONVERT TO 2S COMPLEMENT
015744,000097: 22,3046           64753                           AD       ONE                                   
015745,000098: 22,3047           13051                           TCF      +2                                    
015746,000099: 22,3050           40000                           COM                                            
015747,000100: 22,3051           51272                           INDEX    SPNDX                                 
015748,000101: 22,3052           55640                           TS       DELDCDU                               #  ANGLE INCREMENTS TO BE ADDED TO
015749,000102: 22,3053           51272                           INDEX    SPNDX                                 #  CDUXD, CDUYD, CDUZD EVERY TENTH SECOND

Page 366

015751,000104: 22,3054           31703                           CA       NCDU                                  #  BY LEM DAP
015752,000105: 22,3055           51272                           INDEX    SPNDX                                 
015753,000106: 22,3056           57676                           XCH      BCDU                                  
015754,000107: 22,3057           51272                           INDEX    SPNDX                                 
015755,000108: 22,3060           55635                           TS       CDUXD                                 
015756,000109: 22,3061           11272                           CCS      SPNDX                                 
015757,000110: 22,3062           13035                           TCF      INCRDCDU                              #  LOOP FOR THREE AXES
015758,000111: 
015759,000112: 22,3063           00003                           RELINT                                         
015760,000113: 
015761,000114:                                                                                                  #  COMPARE PRESENT TIME WITH TIME TO TERMINATE MANEUVER
015762,000115: 
015763,000116: 22,3064           03075        TMANUCHK           TC       TIMECHK                               
015764,000117: 22,3065           13170                           TCF      CONTMANU                              
015765,000118: 22,3066           34753                           CAF      ONE                                   
015766,000119: 22,3067           00004        MANUSTAL           INHINT                                         #  END MAJOR PART OF MANEUVER WITHIN 1 SEC
015767,000120: 22,3070           05203                           TC       WAITLIST                              #  UNDER WAITLIST CALL TO MANUSTOP
015768,000121: 22,3071  E6,1707                                  EBANK=   TTEMP                                 
015769,000122: 22,3071           03213 44066                     2CADR    MANUSTOP                              
015770,000123: 
015771,000124: 22,3073           00003                           RELINT                                         
015772,000125: 22,3074           15155                           TCF      ENDOFJOB                              
015773,000126: 
015774,000127: 22,3075           00006        TIMECHK            EXTEND                                         
015775,000128: 22,3076           40025                           DCS      TIME2                                 
015776,000129: 22,3077           53710                           DXCH     TTEMP                                 
015777,000130: 22,3100           00006                           EXTEND                                         
015778,000131: 22,3101           31734                           DCA      TM                                    
015779,000132: 22,3102           21710                           DAS      TTEMP                                 
015780,000133: 22,3103           11707                           CCS      TTEMP                                 
015781,000134: 22,3104           00002                           TC       Q                                     
015782,000135: 22,3105           13107                           TCF      +2                                    
015783,000136: 22,3106           13117                           TCF      2NDRETRN                              
015784,000137: 22,3107           11710                           CCS      TTEMP      +1                         
015785,000138: 22,3110           00002                           TC       Q                                     
015786,000139: 22,3111           13113                           TCF      MANUOFF                               
015787,000140: 22,3112           40000                           COM                                            
015788,000141: 22,3113           63166        MANUOFF            AD       ONESEK     +1                         
015789,000142: 22,3114           00006                           EXTEND                                         
015790,000143: 22,3115           63117                           BZMF     2NDRETRN                              
015791,000144: 22,3116           24002                           INCR     Q                                     
015792,000145: 22,3117           24002        2NDRETRN           INCR     Q                                     
015793,000146: 22,3120           00002                           TC       Q                                     
015794,000147: 
015795,000148: 22,3121           03146        DT/TAU             DEC      .1                                    
015796,000149: 
015797,000150: 22,3122           77776        MANUSTAT           EXIT                                           #  INITIALIZATION ROUTINE
015798,000151: 22,3123           00006                           EXTEND                                         #  FOR AUTOMATIC MANEUVERS
015799,000152: 22,3124           30025                           DCA      TIME2                                 

Page 367

015801,000154: 22,3125           21734                           DAS      TM                                    #  TM+T0         MANEUVER COMPLETION TIME
015802,000155: 22,3126           00006                           EXTEND                                         
015803,000156: 22,3127           43166                           DCS      ONESEK                                
015804,000157: 22,3130           21734                           DAS      TM                                    #  (TM+T0)-1
015805,000158: 22,3131           00004                           INHINT                                         
015806,000159: 22,3132           34752                           CAF      TWO                                   
015807,000160: 22,3133           55701        RATEBIAS           TS       KSPNDX                                
015808,000161: 22,3134           60000                           DOUBLE                                         
015809,000162: 22,3135           55702                           TS       KDPNDX                                
015810,000163: 22,3136           50000                           INDEX    A                                     
015811,000164: 22,3137           31725                           CA       BRATE                                 
015812,000165: 22,3140           51701                           INDEX    KSPNDX                                #  STORE MANEUVER RATE IN
015813,000166: 22,3141           55643                           TS       OMEGAPD                               #  OMEGAPD, OMEGAQD, OMEGARD
015814,000167: 22,3142           00006                           EXTEND                                         
015815,000168: 22,3143           63145                           BZMF     +2                                    #  COMPUTE ATTITUDE ERROR
015816,000169: 22,3144           40000                           COM                                            #  OFFSET = (WX)ABS(WX)/2AJX
015817,000170: 22,3145           00006                           EXTEND                                         #  WHERE AJX= 2-JET ACCELERATION
015818,000171: 22,3146           73167                           MP       BIASCALE                              #  = -1/16
015819,000172: 22,3147           00006                           EXTEND                                         
015820,000173: 22,3150           51702                           INDEX    KDPNDX                                
015821,000174: 22,3151           71725                           MP       BRATE                                 
015822,000175: 22,3152           00006                           EXTEND                                         
015823,000176: 22,3153           51701                           INDEX    KSPNDX                                
015824,000177: 22,3154           11530                           DV       1JACC                                 #  = AJX         $ 90 DEG/SEC-SEC
015825,000178: 22,3155           51701                           INDEX    KSPNDX                                
015826,000179: 22,3156           55277                           TS       DELPEROR                              #                $ 180 DEG
015827,000180: 22,3157           11701                           CCS      KSPNDX                                
015828,000181: 22,3160           13133                           TCF      RATEBIAS                              
015829,000182: 
015830,000183: 22,3161           30025                           CA       TIME1                                 
015831,000184: 22,3162           63166                           AD       ONESEK     +1                         
015832,000185: 22,3163           57706                           XCH      NEXTIME                               
015833,000186: 22,3164           13034                           TCF      INCRDCDU   -1                         
015834,000187: 
015835,000188: 22,3165           00000        ONESEK             DEC      0          B-14                       
015836,000189: 22,3166           00144                           DEC      100        B-14                       
015837,000190: 
015838,000191: 22,3167           75777        BIASCALE           OCT      75777                                 #  = -1/16
015839,000192: 
015840,000193: 22,3170           40025        CONTMANU           CS       TIME1                                 #  RESET FOR NEXT DCDU UPDATE
015841,000194: 22,3171           61706                           AD       NEXTIME                               
015842,000195: 22,3172           10000                           CCS      A                                     
015843,000196: 22,3173           64753                           AD       ONE                                   
015844,000197: 22,3174           13177                           TCF      MANUCALL                              
015845,000198: 22,3175           64735                           AD       NEGMAX                                
015846,000199: 22,3176           40000                           COM                                            
015847,000200: 22,3177           00004        MANUCALL           INHINT                                         #  CALL FOR NEXT UPDATE VIA WAITLIST
015848,000201: 22,3200           05203                           TC       WAITLIST                              
015849,000202: 22,3201  E6,1707                                  EBANK=   TTEMP                                 
015850,000203: 22,3201           03206 44066                     2CADR    UPDTCALL                              

Page 368

015852,000205: 22,3203           33166                           CAF      ONESEK     +1                         #  INCREMENT TIME FOR NEXT UPDATE
015853,000206: 22,3204           27706                           ADS      NEXTIME                               
015854,000207: 22,3205           15155                           TCF      ENDOFJOB                              
015855,000208: 
015856,000209: 22,3206           37714        UPDTCALL           CAF      PRIO26                                #  SATELLITE PROGRAM TO CALL FOR UPDATE
015857,000210: 22,3207           05105                           TC       FINDVAC                               #  OF STEERING COMMANDS
015858,000211: 22,3210  E6,1707                                  EBANK=   TTEMP                                 
015859,000212: 22,3210           03003 44066                     2CADR    NEWDELHI                              
015860,000213: 
015861,000214: 22,3212           05261                           TC       TASKOVER                              
015862,000215: 

Page 369

015864,000217:                                                                                                  #  ROUTINE FOR TERMINATING AUTOMATIC MANEUVERS
015865,000218: 
015866,000219: 22,3213           34755        MANUSTOP           CAF      ZERO                                  #  ZERO MANEUVER RATES
015867,000220: 22,3214           55642                           TS       DELDCDU2                              
015868,000221: 22,3215           55645                           TS       OMEGARD                               
015869,000222: 22,3216           55301                           TS       DELREROR                              
015870,000223: 22,3217           55641                           TS       DELDCDU1                              
015871,000224: 22,3220           55644                           TS       OMEGAQD                               
015872,000225: 22,3221           55300                           TS       DELQEROR                              
015873,000226: 22,3222           30323                           CA       CPSI                                  #  SET DESIRED GIMBAL ANGLES TO
015874,000227: 22,3223           55637                           TS       CDUZD                                 #  DESIRED FINAL GIMBAL ANGLES
015875,000228: 22,3224           30322                           CA       CTHETA                                
015876,000229: 22,3225           55636                           TS       CDUYD                                 
015877,000230: 22,3226           30321        ENDROLL            CA       CPHI                                  #  NO FINAL YAW
015878,000231: 22,3227           55635                           TS       CDUXD                                 
015879,000232: 22,3230           34755                           CAF      ZERO                                  
015880,000233: 22,3231           55643                           TS       OMEGAPD                               #  I.E. MANEUVER DID NOT GO THRU
015881,000234: 22,3232           55640                           TS       DELDCDU                               #  GIMBAL LOCK ORIGINALLY
015882,000235: 22,3233           55277                           TS       DELPEROR                              
015883,000236: 22,3234           31311        GOODMANU           CA       ATTPRIO                               #  RESTORE USERS PRIO
015884,000237: 22,3235           54063                           TS       NEWPRIO                               
015885,000238: 
015886,000239: 22,3236           34755                           CA       ZERO                                  #  ZERO ATTCADR
015887,000240: 22,3237           53310                           DXCH     ATTCADR                               
015888,000241: 
015889,000242: 22,3240           05116                           TC       SPVAC                                 #  RETURN TO USER
015890,000243: 
015891,000244: 22,3241           05261                           TC       TASKOVER                              
015892,000245: 
015893,000246: 

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