Source Code

These source-code files derive from a printout of Luminary 210 (Apollo 15-17 Lunar Module guidance computer program), from the personal library of original AGC developer Don Eyles, digitally photographed at archive.org, financially sponsored by Jim Lawton, and transcribed to source code by a team of volunteers. This colorized, syntax-highlighted form was created by assembling that transcribed source code. Note that the full page images are available on the Virtual AGC project page at archive.org, while reduced-size images are presented at the VirtualAGC project website. Report or fix any transcription errors at the Virtual AGC project code repository.

Notations on the program listing read, in part:

	GAP: ASSEMBLE REVISION 210 OF AGC PROGRAM LUMINARY 
	BY NASA 2021112-161 17:11 MAR. 19,1971
Note that the date is the date of the printout, not the date of the program revision.

063834,000002:                                                                                                  ## Copyright:   Public domain.
063835,000003:                                                                                                  ## Filename:    TRIM_GIMBAL_CONTROL_SYSTEM.agc
063836,000004:                                                                                                  ## Purpose:     A section of Luminary revision 210.
063837,000005:                                                                                                  ##              It is part of the source code for the Lunar Module's (LM)
063838,000006:                                                                                                  ##              Apollo Guidance Computer (AGC) for Apollo 15-17.
063839,000007:                                                                                                  ##              This file is intended to be a faithful transcription, except
063840,000008:                                                                                                  ##              that the code format has been changed to conform to the
063841,000009:                                                                                                  ##              requirements of the yaYUL assembler rather than the
063842,000010:                                                                                                  ##              original YUL assembler.
063843,000011:                                                                                                  ## Reference:   pp. 1470-1482
063844,000012:                                                                                                  ## Assembler:   yaYUL
063845,000013:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
063846,000014:                                                                                                  ## Website:     www.ibiblio.org/apollo/index.html
063847,000015:                                                                                                  ## Mod history: 2016-11-17 JL   Created from Luminary131 version.
063848,000016:                                                                                                  ##              2016-12-26 RSB  Comment-text proofed using ProoferComments
063849,000017:                                                                                                  ##                              and corrected errors found.
063850,000018: 

Page 1470

063852,000020: 21,3027                                           BANK     21                                    
063853,000021: 21,3027  E6,1450                                  EBANK=   QDIFF                                 
063854,000022: 21,2000                                           SETLOC   DAPS4                                 
063855,000023: 21,2000                                           BANK                                           
063856,000024: 
063857,000025: 21,3027                                           COUNT*   $$/DAPGT                              
063858,000026: 
063859,000027:                                                                                                  #  CONTROL REACHES THIS POINT UNDER EITHER OF THE FOLLOWING TWO CONDITIONS ONCE THE DESCENT ENGINE AND THE DIGITAL
063860,000028:                                                                                                  #  AUTOPILOT ARE BOTH ON:
063861,000029:                                                                                                  #           A) THE TRIM GIMBAL CONTROL LAW WAS ON DURING THE PREVIOUS Q,R-AXIS TIME5 INTERRUPT (OR THE DAPIDLER
063862,000030:                                                                                                  #              INITIALIZATION WAS SET FOR TRIM GIMBAL CONTROL AND THIS IS THE FIRST PASS), OR
063863,000031:                                                                                                  #           B) THE Q,R-AXES RCS AUTOPILOT DETERMINED THAT THE VEHICLE WAS ENTERING (OR HAD JUST ENTERED) A COAST
063864,000032:                                                                                                  #              ZONE WITH A SMALL OFFSET ANGULAR ACCELERATION.
063865,000033: 
063866,000034:                                                                                                  #  GTS IS THE ENTRY TO THE GIMBAL TRIM SYSTEM FOR CONTROLLING ATTITUDE ERRORS AND RATES AS WELL AS ACCELERATIONS.
063867,000035: 
063868,000036: 21,3027           37770        GTS                CAF      NEGONE                                #  MAKE THE NEXT PASS THROUGH THE DAP BE
063869,000037: 21,3030           55630                           TS       COTROLER                              #    THROUGH RCS CONTROL,
063870,000038: 21,3031           34742                           CAF      FOUR                                  #    AND ENSURE THAT IT IS NOT A SKIP.
063871,000039: 21,3032           55534                           TS       SKIPU                                 
063872,000040: 21,3033           55535                           TS       SKIPV                                 
063873,000041: 
063874,000042: 21,3034           34743                           CAF      TWO                                   
063875,000043: 21,3035           55632                           TS       INGTS                                 #  SET INDICATOR OF GTS CONTROL POSITIVE.
063876,000044: 21,3036           55631                           TS       QGIMTIMR                              #  SET TIMERS TO 200 MSEC TO AVOID BOTH
063877,000045: 21,3037           55633                           TS       RGIMTIMR                              #  RUNAWAY AND INTERFERENCE BY NULLING.
063878,000046: 
063879,000047:                                                                                                  #  THE DRIVE SETTING ALGORITHM
063880,000048: 
063881,000049:                                                                                                  #  DEL = SGN(OMEGA + ALPHA*ABS(ALPHA)/(2*K))
063882,000050: 
063883,000051:                                                                                                  #                                              2               1/2                  2       3/2
063884,000052:                                                                                                  #  NEGUSUM = ERROR*K + ALPHA*(DEL*OMEGA + ALPHA /(3*K)) + DEL*K   (DEL*OMEGA + ALPHA /(2*K))
063885,000053: 
063886,000054:                                                                                                  #  DRIVE = -SGN(NEGUSUM)
063887,000055: 
063888,000056: 21,3040           30021                           CA       SR                                    #  SAVE THE SR.  SHIFT IT LEFT TO CORRECT
063889,000057: 21,3041           60000                           AD       A                                     #  FOR THE RIGHT SHIFT DUE TO EDITING.
063890,000058: 21,3042           55505                           TS       SAVESR                                
063891,000059: 
063892,000060: 21,3043           34743        GTSGO+DN           CAF      TWO                                   #  SET INDEXER FOR R-AXIS CALCULATIONS.
063893,000061: 21,3044           13046                           TCF      GOQTRIMG   +1                         
063894,000062: 
063895,000063: 21,3045           34746        GOQTRIMG           CAF      ZERO                                  #  SET INDEXER FOR Q-AXIS CALCULATIONS
063896,000064: 21,3046           55747                           TS       QRCNTR                                
063897,000065: 
063898,000066: 21,3047           51747                           INDEX    QRCNTR                                #  AOS SCALED AT PI/2
063899,000067: 21,3050           31536                           CA       AOSQ                                  
063900,000068: 21,3051           00006                           EXTEND                                         
063901,000069: 21,3052           74743                           MP       BIT2                                  #  RESCALE AOS TO PI/4
063902,000070: 

Page 1471

063904,000072: 21,3053           00006                           EXTEND                                         
063905,000073: 21,3054           13060                           BZF      GTSQAXIS   -3                         #  USE FULL SCALE FOR LARGER AOS ESTIMATES.
063906,000074: 
063907,000075: 21,3055           50000                           INDEX    A                                     
063908,000076: 21,3056           44725                           CS       LIMITS                                #  LIMITS +1 CONTAINS NEGMAX.
063909,000077: 21,3057           56001                           XCH      L                                     #  LIMITS -1 CONTAINS POSMAX.
063910,000078: 
063911,000079: 21,3060           11747                           CCS      QRCNTR                                #  PICK UP RATE FOR THIS AXIS.  RATE CELLS
063912,000080: 21,3061           50000                           INDEX    A                                     #  ARE ADJACENT, NOT SEPARATED.  AT PI/4
063913,000081: 21,3062           31436                           CA       EDOTQ                                 
063914,000082: 21,3063           53743        GTSQAXIS           DXCH     WCENTRAL                              
063915,000083: 
063916,000084: 21,3064           51747                           INDEX    QRCNTR                                #  COLLECT K FOR THIS AXIS
063917,000085: 21,3065           31504                           CA       KQ                                    
063918,000086: 21,3066           55740                           TS       KCENTRAL                              
063919,000087: 
063920,000088: 21,3067           00006                           EXTEND                                         #  CONTROL AUTHORITY  ZERO.  AVOID DRIVING
063921,000089: 21,3070           13526                           BZF      POSDRIVE   +1                         #  ENGINE BELL TO THE STOPS.
063922,000090: 
063923,000091: 21,3071           51747                           INDEX    QRCNTR                                #  QDIFF, RDIFF ARE STORED IN D.P.
063924,000092: 21,3072           31450                           CAE      QDIFF                                 
063925,000093: 
063926,000094: 21,3073           00006        ALGORTHM           EXTEND                                         #  Q(R)DIFF IS THETA (ERROR) SCALED AT PI.
063927,000095: 21,3074           71740                           MP       KCENTRAL                              #  FORM K*ERROR AT PI(2)/2(8), IN D.P.
063928,000096: 21,3075           23736                           LXCH     K2THETA                               
063929,000097: 21,3076           00006                           EXTEND                                         
063930,000098: 21,3077           74740                           MP       BIT5                                  #  RESCALE TO 4*PI(2)
063931,000099: 21,3100           53737                           DXCH     K2THETA                               
063932,000100: 21,3101           00006                           EXTEND                                         
063933,000101: 21,3102           74740                           MP       BIT5                                  #  FIRST TERM OF NEGUSUM IN K2THETA.
063934,000102: 21,3103           27737                           ADS      K2THETA    +1                         #  NO CARRY NEEDED    D.P. AT 4*PI(2)
063935,000103: 
063936,000104: 21,3104           41743                           CS       ACENTRAL                              #  FORM ALPHA(2)/(2*K) AT 16*PI, IN D.P.,
063937,000105: 21,3105           00006                           EXTEND                                         #  LIMITING QUOTIENT TO AVOID OVERFLOW.
063938,000106: 21,3106           74727                           MP       BIT14                                 #  -ALPHA/2 IN A, SCALED AT PI/4
063939,000107: 21,3107           00006                           EXTEND                                         
063940,000108: 21,3110           71743                           MP       ACENTRAL                              #  -ALPHA(2)/2 IN A,L, SCALED AT PI(2)/16
063941,000109: 21,3111           61740                           AD       KCENTRAL                              
063942,000110: 21,3112           00006                           EXTEND                                         
063943,000111: 21,3113           63130                           BZMF     HUGEQUOT                              #  K-ALPHA(2)/2 SHOULD BE PNZ FO DIVISION
063944,000112: 
063945,000113: 21,3114           00006                           EXTEND                                         
063946,000114: 21,3115           40001                           DCS      A                                     #  ALPHA(2)/2 - K
063947,000115: 21,3116           61740                           AD       KCENTRAL                              
063948,000116: 21,3117           00006                           EXTEND                                         
063949,000117: 21,3120           11740                           DV       KCENTRAL                              #  HIGH ORDER OF QUOTIENT.
063950,000118: 21,3121           57745                           XCH      A2CNTRAL                              
063951,000119: 21,3122           30001                           CA       L                                     #  SHIFT UP THE REMAINDER.
063952,000120: 21,3123           22007                           LXCH     7                                     #  ZERO LOW-ORDER DIVIDEND.
063953,000121: 21,3124           00006                           EXTEND                                         
063954,000122: 

Page 1472

063956,000124: 21,3125           11740                           DV       KCENTRAL                              
063957,000125: 21,3126           57746                           XCH      A2CNTRAL   +1                         #  QUOTIENT STORED AT 16*PI, D.P.
063958,000126: 21,3127           13133                           TCF      HAVEQUOT                              
063959,000127: 
063960,000128: 21,3130           34724        HUGEQUOT           CA       POSMAX                                
063961,000129: 21,3131           54001                           TS       L                                     
063962,000130: 21,3132           53746                           DXCH     A2CNTRAL                              #  LIMITED QUOTIENT STORED AT 16*PI, D.P.
063963,000131: 
063964,000132: 21,3133           31742        HAVEQUOT           CA       WCENTRAL                              
063965,000133: 21,3134           00006                           EXTEND                                         
063966,000134: 21,3135           74734                           MP       BIT9                                  #  RESCALE OMEGA AT 16*PI IN D.P.
063967,000135: 21,3136           53742                           DXCH     K2CNTRAL                              #  LOWER WORD OVERLAYS OMEGA IN WCENTRAL
063968,000136: 
063969,000137: 21,3137           00006                           EXTEND                                         
063970,000138: 21,3140           31742                           DCA      K2CNTRAL                              
063971,000139: 21,3141           53751                           DXCH     FUNCTION                              
063972,000140: 
063973,000141: 21,3142           31743                           CA       ACENTRAL                              #  GET ALPHA*ABS(ALPHA)/(2*K)
063974,000142: 21,3143           00006                           EXTEND                                         
063975,000143: 21,3144           63150                           BZMF     +4                                    
063976,000144: 
063977,000145: 21,3145           00006                           EXTEND                                         
063978,000146: 21,3146           31746                           DCA      A2CNTRAL                              
063979,000147: 21,3147           13152                           TCF      +3                                    
063980,000148: 
063981,000149: 21,3150           00006                           EXTEND                                         
063982,000150: 21,3151           41746                           DCS      A2CNTRAL                              
063983,000151: 
063984,000152: 21,3152           21751                           DAS      FUNCTION                              #  OMEGA + ALPHA*ABS(ALPHA)/2*K) AT 16*PI
063985,000153: 
063986,000154: 21,3153           11750                           CCS      FUNCTION                              #  DEL = +1 FOR FUNCT1 GREATER THAN ZERO.
063987,000155: 21,3154           13160                           TCF      POSFNCT1                              #  OTHERWISE DEL = -1
063988,000156: 21,3155           13157                           TCF      +2                                    
063989,000157: 21,3156           13162                           TCF      NEGFNCT1                              
063990,000158: 
063991,000159: 21,3157           11751                           CCS      FUNCTION   +1                         #  USE LOW ORDER WORD SINCE HIGH IS ZERO
063992,000160: 21,3160           34744        POSFNCT1           CAF      BIT1                                  
063993,000161: 21,3161           13163                           TCF      +2                                    
063994,000162: 21,3162           44744        NEGFNCT1           CS       BIT1                                  
063995,000163: 21,3163           55744                           TS       DEL                                   
063996,000164: 
063997,000165: 21,3164           11744                           CCS      DEL                                   #  REPLACE OMEGA BY DEL*OMEGA
063998,000166: 21,3165           13177                           TCF      FUNCT2                                #  POSITIVE DEL VALUE.  PROCEED.
063999,000167: 21,3166           13170                           TCF      DEFUNCT                               
064000,000168: 21,3167           13174                           TCF      NEGFNCT2                              
064001,000169: 
064002,000170: 21,3170           55741        DEFUNCT            TS       K2CNTRAL                              
064003,000171: 21,3171           55742                           TS       K2CNTRAL   +1                         
064004,000172: 21,3172           13177                           TCF      FUNCT2                                
064005,000173: 

Page 1473

064007,000175: 21,3173           65252        NEG1/3             DEC      -.33333                               
064008,000176: 
064009,000177: 21,3174           00006        NEGFNCT2           EXTEND                                         
064010,000178: 21,3175           41742                           DCS      K2CNTRAL                              
064011,000179: 21,3176           53742                           DXCH     K2CNTRAL                              
064012,000180: 
064013,000181: 21,3177           00006        FUNCT2             EXTEND                                         
064014,000182: 21,3200           31746                           DCA      A2CNTRAL                              
064015,000183: 21,3201           21742                           DAS      K2CNTRAL                              #  DEL*OMEGA + ALPHA(2)/(2*K) AT 16*PI, D.P.
064016,000184: 
064017,000185: 21,3202           31745        FUNCT3             CA       A2CNTRAL                              
064018,000186: 21,3203           00006                           EXTEND                                         
064019,000187: 21,3204           73173                           MP       NEG1/3                                
064020,000188: 21,3205           53746                           DXCH     A2CNTRAL                              
064021,000189: 21,3206           30001                           CA       L                                     
064022,000190: 21,3207           00006                           EXTEND                                         
064023,000191: 21,3210           73173                           MP       NEG1/3                                
064024,000192: 21,3211           27746                           ADS      A2CNTRAL   +1                         
064025,000193: 21,3212           54001                           TS       L                                     
064026,000194: 21,3213           13215                           TCF      +2                                    #  A2CNTRAL NOW CONTAINS  -ALPHA(2)/(6*K),
064027,000195: 21,3214           27745                           ADS      A2CNTRAL                              #  SCALED AT 16*PI, IN D.P.
064028,000196: 
064029,000197: 21,3215           00006                           EXTEND                                         
064030,000198: 21,3216           31742                           DCA      K2CNTRAL                              #  DEL*OMEGA + ALPHA(2)/(3*K) IN A2CNTRAL,
064031,000199: 21,3217           21746                           DAS      A2CNTRAL                              #  SCALED AT 16*PI, D.P.
064032,000200: 
064033,000201: 21,3220           31745                           CA       A2CNTRAL                              
064034,000202: 21,3221           00006                           EXTEND                                         
064035,000203: 21,3222           71743                           MP       ACENTRAL                              
064036,000204: 21,3223           21737                           DAS      K2THETA                               
064037,000205: 21,3224           31746                           CA       A2CNTRAL   +1                         
064038,000206: 21,3225           00006                           EXTEND                                         
064039,000207: 21,3226           71743                           MP       ACENTRAL                              #  ACENTRAL MAY NOW BE OVERLAID.
064040,000208: 21,3227           27737                           ADS      K2THETA    +1                         
064041,000209: 21,3230           54001                           TS       L                                     
064042,000210: 21,3231           13233                           TCF      +2                                    #  TWO TERMS OF NEGUSUM ACCUMULATED, SO FAR
064043,000211: 21,3232           27736                           ADS      K2THETA                               #  SCALED AT 4*PI(2), IN D.P.
064044,000212: 
064045,000213: 21,3233           31741        GETROOT            CA       K2CNTRAL                              #  K*(DEL*OMEGA + ALPHA(2)/(2*K)) IS THE
064046,000214: 21,3234           00006                           EXTEND                                         #  TERM FOR WHICH A SQUARE ROOT IS NEEDED.
064047,000215: 21,3235           71740                           MP       KCENTRAL                              #  K AT PI/2(8)
064048,000216: 21,3236           53751                           DXCH     FUNCTION                              
064049,000217: 21,3237           31742                           CA       K2CNTRAL   +1                         
064050,000218: 21,3240           00006                           EXTEND                                         
064051,000219: 21,3241           71740                           MP       KCENTRAL                              
064052,000220: 21,3242           27751                           ADS      FUNCTION   +1                         
064053,000221: 21,3243           54001                           TS       L                                     
064054,000222: 21,3244           13246                           TCF      +2                                    
064055,000223: 21,3245           27750                           ADS      FUNCTION                              #  DESIRED TERM IN FUNCTION, AT PI(2)/16

Page 1474

064057,000225: 21,3246           11744                           CCS      DEL                                   
064058,000226: 21,3247           13454                           TCF      RSTOFGTS                              
064059,000227: 21,3250           13516                           TCF      NEGUSUM                               
064060,000228: 21,3251           13253                           TCF      NEGATE                                
064061,000229: 21,3252           13516                           TCF      NEGUSUM                               
064062,000230: 
064063,000231: 21,3253           00006        NEGATE             EXTEND                                         
064064,000232: 21,3254           41742                           DCS      K2CNTRAL                              
064065,000233: 21,3255           53742                           DXCH     K2CNTRAL                              
064066,000234: 21,3256           13454                           TCF      RSTOFGTS                              
064067,000235: 
064068,000236: 16,3736                                           BANK     16                                    
064069,000237: 16,3736  E6,1501                                  EBANK=   NEGUQ                                 
064070,000238: 16,2000                                           SETLOC   DAPS1                                 
064071,000239: 16,2000                                           BANK                                           
064072,000240: 
064073,000241:                                                                                                  #  THE WRCHN12 SUBROUTINE SETS BITS 9,10,11,12 OF CHANNEL 12 ON THE BASIS OF THE CONTENTS OF NEGUQ,NEGUR WHICH ARE
064074,000242:                                                                                                  #  THE NEGATIVES OF THE DESIRED ACCELERATION CHANGES.  ACDT+C12 SETS Q(R)ACCDOT TO REFLECT THE NEW DRIVES.
064075,000243: 
064076,000244:                                                                                                  #  WARNING:  ACDT+C12 AND WRCHN12 MUST BE CALLED WITH INTERRUPT INHIBITED.
064077,000245: 
064078,000246: 16,3736           07400        BGIM               OCTAL    07400                                 
064079,000247: 16,3737     0066               CHNL12             EQUALS   ITEMP6                                
064080,000248: 16,3737           41501        ACDT+C12           CS       NEGUQ                                 
064081,000249: 16,3740           00006                           EXTEND                                         #  GIMBAL DRIVE REQUESTS.
064082,000250: 16,3741           71507                           MP       ACCDOTQ                               
064083,000251: 16,3742           23510                           LXCH     QACCDOT                               
064084,000252: 16,3743           41503                           CS       NEGUR                                 
064085,000253: 16,3744           00006                           EXTEND                                         
064086,000254: 16,3745           71511                           MP       ACCDOTR                               
064087,000255: 16,3746           23512                           LXCH     RACCDOT                               
064088,000256: 
064089,000257: 16,3747           11501                           CCS      NEGUQ                                 
064090,000258: 16,3750           34733                           CAF      BIT10                                 
064091,000259: 16,3751           13753                           TCF      +2                                    
064092,000260: 16,3752           34734                           CAF      BIT9                                  
064093,000261: 16,3753           54066                           TS       CHNL12                                
064094,000262: 
064095,000263: 16,3754           11503                           CCS      NEGUR                                 
064096,000264: 16,3755           34731                           CAF      BIT12                                 
064097,000265: 16,3756           13760                           TCF      +2                                    
064098,000266: 16,3757           34732                           CAF      BIT11                                 
064099,000267: 16,3760           26066                           ADS      CHNL12                                #  (STORED RESULT NOT USED AT PRESENT)
064100,000268: 
064101,000269: 16,3761           43736                           CS       BGIM                                  
064102,000270: 16,3762           00006                           EXTEND                                         
064103,000271: 16,3763           02012                           RAND     CHAN12                                
064104,000272: 16,3764           60066                           AD       CHNL12                                
064105,000273: 16,3765           00006                           EXTEND                                         
064106,000274: 16,3766           01012                           WRITE    CHAN12                                
064107,000275: 

Page 1475

064109,000277: 16,3767           44740                           CS       CALLGMBL                              #  TURN OFF REQUEST FOR ACDT+C12 EXECUTION.
064110,000278: 16,3770           71774                           MASK     RCSFLAGS                              
064111,000279: 16,3771           55774                           TS       RCSFLAGS                              
064112,000280: 
064113,000281: 16,3772           00002                           TC       Q                                     #  RETURN TO CALLER.
064114,000282: 
064115,000283: 21,3257                                           BANK     21                                    
064116,000284: 21,3257  E6,1450                                  EBANK=   QDIFF                                 
064117,000285: 21,2000                                           SETLOC   DAPS4                                 
064118,000286: 21,2000                                           BANK                                           
064119,000287: 

Page 1476

064121,000289:                                                                                                  #  SUBROUTINE TIMEGMBL:  MOD 0,  OCTOBER 1967, CRAIG WORK
064122,000290: 
064123,000291:                                                                                                  #  TIMEGMBL COMPUTES THE DRIVE TIME NEEDED FOR THE TRIM GIMBAL TO POSITION THE DESCENT ENGINE NOZZLE SO AS TO NULL
064124,000292:                                                                                                  #  THE OFFSET ANGULAR ACCELERATION ABOUT THE Q (OR R) AXIS.  INSTEAD OF USING AOSQ(R), TIMEGMBL USES .4*AOSQ(R),
064125,000293:                                                                                                  #  SCALED AT PI/8.                         FOR EACH AXIS, THE DRIVE TIME IS COMPUTED AS ABS(ALPHA/ACCDOT).  A ZERO
064126,000294:                                                                                                  #  ALPHA OR ACCDOT OR A ZERO QUOTIENT TURNS OFF THE GIMBAL DRIVE IMMEDIATELY.  OTHERWISE, THE GIMBAL IS TURNED ON
064127,000295:                                                                                                  #  DRIVING IN THE CORRECT DIRECTION. THE Q(R)GIMTIMR IS SET TO TERMINATE THE DRIVE AND Q(R)ACCDOT
064128,000296:                                                                                                  #  IS STORED TO REFLECT THE NEW ACCELERATION DERIVATIVE.  NEGUQ(R) WILL CONTAIN +1,+0,-1 FOR A Q(R)ACCDOT VALUE
064129,000297:                                                                                                  #  WHICH IS NEGATIVE, ZERO, OR POSITIVE.
064130,000298: 
064131,000299:                                                                                                  #  INPUTS:  AOSQ,AOSR, SCALED AT P1/2, AND ACCDOTQ, ACCDOTR AT PI/2(7).    PI/2(7).
064132,000300: 
064133,000301:                                                                                                  #  OUTPUTS:   NEW GIMBAL DRIVE BITS IN CHANNEL 12,NEGUQ,NEGUR,QACCDOT AND RACCDOT, THE LAST SCALED AT PI/2(7).
064134,000302:                                                                                                  #             Q(R)GIMTIMR WILL BE SET TO TIME AND TERMINATE GIMBAL DRIVE(S)
064135,000303: 
064136,000304:                                                                                                  #  DEBRIS:  A,L,Q, ITEMPS 2,3,6, RUPTREG2 AND ACDT+C12 DEBRIS.
064137,000305: 
064138,000306:                                                                                                  #  EXITS:  VIA TC Q.
064139,000307: 
064140,000308:                                                                                                  #  ALARMS, ABORTS, :  NONE
064141,000309: 
064142,000310:                                                                                                  #  SUBROUTINES:  ACDT+C12, IBNKCALL
064143,000311: 
064144,000312:                                                                                                  #  WARNING:  THIS SUBROUTINE WRITES INTO CHANNEL 12 AND USES THE ITEMPS.  THEREFORE IT MAY ONLY BE CALLED WITH
064145,000313:                                                                                                  #  INTERRUPT INHIBITED.
064146,000314: 
064147,000315:                                                                                                  #  ERASABLE STORAGE CONFIGURATION (NEEDED BY THE INDEXING METHODS):
064148,000316: 
064149,000317:                                                                                                  #                                          NEGUQ    ERASE    +2            NEGATIVE OF Q-AXIS GIMBAL DRIVE
064150,000318:                                                                                                  #                                          (SPWORD) EQUALS  NEGUQ +1       ANY S.P. ERASABLE NUMBER, NOW THRSTCMD
064151,000319:                                                                                                  #                                          NEGUR    EQUALS  NEGUQ +2       NEGATIVE OF R-AXIS GIMBAL DRIVE
064152,000320: 
064153,000321:                                                                                                  #                                          ACCDOTQ  ERASE    +2            Q-JERK TERM SCALED AT PI/2(7) RAD/SEC(3)
064154,000322:                                                                                                  #                                          (SPWORD) EQUALS  ACCDOTQ +1     ANY S.P. ERASABLE NUMBER  NOW QACCDOT
064155,000323:                                                                                                  #                                          ACCDOTR  EQUALS  ACCDOTQ +2     R-JERK TERM SCALED AT PI/2(7) RAD/SEC(3)
064156,000324:                                                                                                  #                                                                          ACCDOTQ,ACCDOTR ARE MAGNITUDES.
064157,000325:                                                                                                  #                                          AOSQ     ERASE   +4             Q-AXIS ACC.,D.P. AT PI/2 R/SEC(2)
064158,000326:                                                                                                  #                                          AOSR     EQUALS  AOSQ +2        R-AXIS ACCELERATION SCALED AT PI/2 R/S2
064159,000327: 
064160,000328: 21,3257     0066               QRNDXER            EQUALS   ITEMP6                                
064161,000329: 21,3257           23146        OCT23146           OCTAL    23146                                 #  DECIMAL .6
064162,000330: 21,3260     0063               NZACCDOT           EQUALS   ITEMP3                                
064163,000331: 
064164,000332: 21,3260           34744        TIMEGMBL           CAF      ONE                                   #  INITIALIZE ALLOWGTS.
064165,000333: 21,3261           55502                           TS       ALLOWGTS                              
064166,000334: 
064167,000335: 21,3262           34743                           CAF      TWO                                   #  SET UP LOOP FOR R AXIS.
064168,000336: 21,3263           22002                           LXCH     Q                                     #  SAVE RETURN ADDRESS.
064169,000337: 21,3264           22071                           LXCH     RUPTREG2                              
064170,000338: 

Page 1477

064172,000340: 21,3265           13267                           TCF      +2                                    
064173,000341: 21,3266           34746        TIMQGMBL           CAF      ZERO                                  #  NOW DO THE Q-AXIS
064174,000342: 21,3267           54066                           TS       QRNDXER                               
064175,000343: 21,3270           50066                           INDEX    QRNDXER                               
064176,000344: 21,3271           31507                           CA       ACCDOTQ                               #  ACCDOT IS PRESUMED TO BE AT PI/2(7).
064177,000345: 21,3272           00006                           EXTEND                                         
064178,000346: 21,3273           63343                           BZMF     TGOFFNOW                              #  IS ACCDOT LESS THAN OR EQUAL TO 0?
064179,000347: 21,3274           54063                           TS       NZACCDOT                              #  NO.  STORE NON-ZERO, POSITIVE ACCDOT.
064180,000348: 
064181,000349: 21,3275           50066        ALPHATRY           INDEX    QRNDXER                               
064182,000350: 21,3276           41536                           CS       AOSQ                                  
064183,000351: 21,3277           00006                           EXTEND                                         
064184,000352: 21,3300           13343                           BZF      TGOFFNOW                              #  IS ALPHA ZERO?
064185,000353: 
064186,000354: 21,3301           54002                           TS       Q                                     #  SAVE A COPY OF -AOS.
064187,000355: 21,3302           00006                           EXTEND                                         #  NO.  RESCALE FOR TIMEGMBL USE.
064188,000356: 21,3303           73257                           MP       OCT23146                              #  OCTAL 23146 IS DECIMAL .6
064189,000357: 21,3304           60002                           AD       Q                                     #  -1.6*AOS AT PI/2 = -.4*AOS AT PI/8.
064190,000358: 21,3305           54001                           TS       L                                     #  WAS THERE OVERFLOW?
064191,000359: 21,3306           13313                           TCF      SETNEGU                               #  NO.  COMPUTE DRIVE TIME.
064192,000360: 
064193,000361: 21,3307           40000                           CS       A                                     #  RECOVER  -SGN(AOS) IN THE A REGISTER.
064194,000362: 21,3310           50066                           INDEX    QRNDXER                               #  YES.  START DRIVE WITHOUT WAITLIST.
064195,000363: 21,3311           57501                           XCH      NEGUQ                                 
064196,000364: 21,3312           13347                           TCF      NOTALLOW                              #  KNOCK DOWN THE ALLOWGTS FLAG.
064197,000365: 
064198,000366: 21,3313           00006        SETNEGU            EXTEND                                         
064199,000367: 21,3314           63321                           BZMF     POSALPH                               
064200,000368: 
064201,000369: 21,3315           40000                           COM                                            
064202,000370: 21,3316           54062                           TS       ITEMP2                                #  STORE  -ABS(.4*AOS) SCALED AT PI/8.
064203,000371: 21,3317           44744                           CS       BIT1                                  
064204,000372: 21,3320           13323                           TCF      POSALPH    +2                         
064205,000373: 21,3321           54062        POSALPH            TS       ITEMP2                                #  STORE  -ABS(.4*AOS) SCALED AT PI/8.
064206,000374: 21,3322           34744                           CA       BIT1                                  
064207,000375: 21,3323           50066                 +2        INDEX    QRNDXER                               #  SGN(AOS) INTO NEGU
064208,000376: 21,3324           55501                           TS       NEGUQ                                 #  STORE SGN(APLHA) AS NEGU
064209,000377: 
064210,000378: 21,3325           30063                           CA       NZACCDOT                              
064211,000379: 21,3326           00006                           EXTEND                                         
064212,000380: 21,3327           74731                           MP       BIT12                                 #  2*ACCDOT, SCALED AT PI/8.
064213,000381: 21,3330           60062                           AD       ITEMP2                                #  -ABS(ALPHA) + 2*ACCDOT, AT PI/8.
064214,000382: 21,3331           00006                           EXTEND                                         
064215,000383: 21,3332           63347                           BZMF     NOTALLOW                              #  IS DRIVE TIME MORE THAN TWO SECONDS?
064216,000384: 21,3333           40062                           CS       ITEMP2                                #  NO.  COMPUTE DRIVE TIME.
064217,000385: 21,3334           00006                           EXTEND                                         #  ABS(ALPHA) AT PI/8.
064218,000386: 21,3335           73370                           MP       OCT00240                              #  DECIMAL 10/1024
064219,000387: 21,3336           00006                           EXTEND                                         #  QUOTIENT IS DRIVE TIME AT WAITLIST.
064220,000388: 21,3337           10063                           DV       NZACCDOT                              #  ABS(ALPHA)/ACCDOT AT 2(14)/100
064221,000389: 

Page 1478

064223,000391: 21,3340           00006                           EXTEND                                         
064224,000392: 21,3341           13343                           BZF      TGOFFNOW                              #  DRIVE TIME MUST BE GREATER THAN ZERO.
064225,000393: 
064226,000394: 21,3342           13355                           TCF      DRIVEON                               
064227,000395: 
064228,000396: 21,3343           34746        TGOFFNOW           CAF      ZERO                                  #  TURN OFF GIMBAL NOW.
064229,000397: 21,3344           50066                           INDEX    QRNDXER                               
064230,000398: 21,3345           55501                           TS       NEGUQ                                 
064231,000399: 
064232,000400: 21,3346           13357                           TCF      DONEYET                               
064233,000401: 
064234,000402: 21,3347           36010        NOTALLOW           CAF      OCT31                                 
064235,000403: 21,3350           50066                           INDEX    QRNDXER                               
064236,000404: 21,3351           55631                           TS       QGIMTIMR                              
064237,000405: 21,3352           34746                           CAF      ZERO                                  #  DRIVE TIME IS MORE THAN 2 SECONDS, SO
064238,000406: 21,3353           55502                           TS       ALLOWGTS                              #  DO NOT PERMIT FURTHER GTS ATTITUDE-RATE
064239,000407:                                                                                                  #  CONTROL UNTIL AOSTASK APPROVES.
064240,000408: 21,3354           13357                           TCF      DONEYET                               #  NO WAITLIST CALL IS MADE.
064241,000409: 
064242,000410: 21,3355           50066        DRIVEON            INDEX    QRNDXER                               
064243,000411: 21,3356           55631                           TS       QGIMTIMR                              #  CHOOSE Q OR R AXIS.
064244,000412: 
064245,000413: 21,3357           10066        DONEYET            CCS      QRNDXER                               
064246,000414: 21,3360           13266                           TCF      TIMQGMBL                              
064247,000415: 
064248,000416: 21,3361           52073                           DXCH     RUPTREG3                              #  PROTECT IBNKCALL ERASABLES.  ACDT+C12
064249,000417: 21,3362           52063                           DXCH     ITEMP2                                #  LEAVES ITEMPS2,3 ALONE.
064250,000418: 
064251,000419: 21,3363           04665                           TC       IBNKCALL                              #  TURN OF CHANNEL BITS, SET Q(R)ACCDOTS.
064252,000420: 21,3364           35737                           CADR     ACDT+C12                              
064253,000421: 
064254,000422: 21,3365           52063                           DXCH     ITEMP2                                #  RESTORE ERASABLES FOR IBNKCALL.
064255,000423: 21,3366           52073                           DXCH     RUPTREG3                              
064256,000424: 
064257,000425: 21,3367           00071                           TC       RUPTREG2                              #  RETURN TO CALLER.
064258,000426: 
064259,000427: 21,3370           00240        OCT00240           OCTAL    00240                                 #  DECIMAL 10/1024
064260,000428: 

Page 1479

064262,000430:                                                                                                  #  THE FOLLOWING SECTION IS A CONTINUATION OF THE TRIM GIMBAL CONTROL FROM THE LAST GTS ENTRY. THE QUANTITY NEGUSUM
064263,000431:                                                                                                  #  IS COMPUTED FOR EACH AXIS (Q,R), .707*DEL*FUNCTION(3/2) + K2THETA = NEGUSUM.  NEW DRIVES ARE ENTERED TO CH 12.
064264,000432: 
064265,000433:                                                                                                  #  THE SUBROUTINE GTSQRT ACCEPTS A DOUBLE PRECISION VALUE IN FUNCTION, FUNCTION +1 AND RETURNS A SINGLE-PRECISION
064266,000434:                                                                                                  #  SQUARE ROOT OF THE FOURTEEN MOST SIGNIFICANT BITS OF THE ARGUMENT.  ALSO, THE CELL SHFTFLAG CONTAINS A BINARY
064267,000435:                                                                                                  #  EXPONENT S, SUCH THAT THE SQUARE ROOT (RETURNED IN THE A REGISTER) MUST BE SHIFTED RIGHT (MULTIPLIED BY 2 TO THE
064268,000436:                                                                                                  #  POWER (-S)) IN ORDER TO BE THE TRUE SQUARE ROOT OF THE FOURTEEN MOST SIGNIFICANT BITS OF FUNCTION, FUNCTION +1.
064269,000437:                                                                                                  #  SQUARE ROOT ERROR IS NOT MORE THAN 2 IN THE 14TH SIGNIFICANT BIT.  CELLS CLOBBERED ARE A,L,SHFTFLAG,ININDEX,
064270,000438:                                                                                                  #  HALFARG,SCRATCH,SR,FUNCTION, FUNCTION +1.  GTSQRT IS CALLED BY TC GTSQRT AND RETURNS VIA TC Q OR TC FUNCTION +1.
064271,000439:                                                                                                  #  ZERO OR NEGATIVE ARGUMENTS YIELD ZERO FOR SQUARE ROOTS.
064272,000440: 
064273,000441: 21,3371           11750        GTSQRT             CCS      FUNCTION                              
064274,000442: 21,3372           13410                           TCF      GOODARG                               #  FUNCTION IS POSITIVE.  TAKE SQUARE ROOT.
064275,000443: 21,3373           13375                           TCF      +2                                    #  HIGH ORDER WORD IS ZERO.  TRY THE LOWER.
064276,000444: 21,3374           13401                           TCF      ZEROOT                                #  NEGATIVE.  USE ZERO FOR 1/2 POWER.
064277,000445: 
064278,000446: 21,3375           31751                           CA       FUNCTION   +1                         
064279,000447: 21,3376           00006                           EXTEND                                         
064280,000448: 21,3377           63401                           BZMF     ZEROOT                                
064281,000449: 
064282,000450: 21,3400           13404                           TCF      ZEROHIGH                              #  PROCEED.
064283,000451: 21,3401           34746        ZEROOT             CA       ZERO                                  
064284,000452: 21,3402           55740                           TS       SHFTFLAG                              
064285,000453: 21,3403           00002                           TC       Q                                     
064286,000454: 
064287,000455: 21,3404           57750        ZEROHIGH           XCH      FUNCTION                              #  14 MOST SIGNIFICANT BITS ARE IN THE
064288,000456: 21,3405           57751                           XCH      FUNCTION   +1                         #  LOWER WORD.  EXCHANGE THEM.
064289,000457: 21,3406           34750                           CA       SEVEN                                 
064290,000458: 21,3407           13411                           TCF      GOODARG    +1                         
064291,000459: 
064292,000460: 21,3410           34746        GOODARG            CA       ZERO                                  
064293,000461: 21,3411           55740                           TS       SHFTFLAG                              
064294,000462: 21,3412           35745                           CA       TWELVE                                #  INITIALIZE THE SCALING LOOP.
064295,000463: 21,3413           55743                           TS       ININDEX                               
064296,000464: 21,3414           13423                           TCF      SCALLOOP                              
064297,000465: 
064298,000466: 21,3415           31750        SCALSTRT           CA       FUNCTION                              
064299,000467: 21,3416           13437                           TCF      SCALDONE                              
064300,000468: 
064301,000469: 21,3417           37767        MULBUSH            CA       NEG2                                  #  IF ARG IS NOT LESS THAN 1/4, INDEX IS
064302,000470: 21,3420           27743                           ADS      ININDEX                               #  ZERO, INDICATING NO SHIFT NEEDED.
064303,000471: 21,3421           00006                           EXTEND                                         #  BRANCH IF ARG IS NOT LESS THAN 1/4.
064304,000472: 21,3422           63415                           BZMF     SCALSTRT                              #  OTHERWISE COMPARE ARG WITH A REFERENCE
064305,000473:                                                                                                  #  WHICH IS 4 TIMES LARGER THAN THE LAST.
064306,000474: 21,3423           41750        SCALLOOP           CS       FUNCTION                              
064307,000475: 21,3424           51743                           INDEX    ININDEX                               
064308,000476: 21,3425           64726                           AD       BIT15                                 #  REFERENCE MAGNITUDE LESS OR EQUAL TO 1/4
064309,000477: 21,3426           00006                           EXTEND                                         
064310,000478: 21,3427           63417                           BZMF     MULBUSH                               #  IF ARG IS NOT LESS THAN REFERENCE, GO
064311,000479:                                                                                                  #  AROUND THE MULBERRY BUSH ONCE MORE.
064312,000480: 

Page 1480

064314,000482: 21,3430           51743                           INDEX    ININDEX                               
064315,000483: 21,3431           34726                           CA       BIT15                                 #  THIS IS THE SCALE MAGNITUDE
064316,000484: 21,3432           57746                           XCH      HALFARG                               #  2**(-ININDEX) IS THE SHIFT DIVISOR.
064317,000485: 21,3433           00006                           EXTEND                                         #  RESCALE ARGUMENT.
064318,000486: 21,3434           31751                           DCA      FUNCTION                              
064319,000487: 21,3435           00006                           EXTEND                                         
064320,000488: 21,3436           11746                           DV       HALFARG                               
064321,000489:                                                                                                  #  ININDEX AND SHFTFLAG PRESERVE INFO FOR
064322,000490: 
064323,000491:                                                                                                  #  RESCALING AFTER ROOT PROCESS.
064324,000492: 21,3437           00006        SCALDONE           EXTEND                                         
064325,000493: 21,3440           23751                           QXCH     FUNCTION   +1                         #  SAVE Q FOR RETURN
064326,000494: 21,3441           00006                           EXTEND                                         
064327,000495: 21,3442           74727                           MP       BIT14                                 
064328,000496: 21,3443           55746                           TS       HALFARG                               
064329,000497: 21,3444           74730                           MASK     BIT13                                 
064330,000498: 21,3445           10000                           CCS      A                                     
064331,000499: 21,3446           33564                           CA       OCT11276                              
064332,000500: 21,3447           63562                           AD       ROOTHALF                              #  INITIAL GUESS IS ROOT 1/2 OR POSMAX
064333,000501: 
064334,000502: 21,3450           03566                           TC       ROOTCYCL                              
064335,000503: 21,3451           03566                           TC       ROOTCYCL                              
064336,000504: 21,3452           03566                           TC       ROOTCYCL                              
064337,000505: 
064338,000506: 21,3453           01751                           TC       FUNCTION   +1                         
064339,000507: 
064340,000508:                                                                                                  #  ****************************************************************************************************************
064341,000509: 
064342,000510: 
064343,000511: 21,3454           03371        RSTOFGTS           TC       GTSQRT                                
064344,000512: 21,3455           57741        PRODUCT            XCH      K2CNTRAL                              
064345,000513: 21,3456           00006                           EXTEND                                         
064346,000514: 21,3457           71741                           MP       K2CNTRAL                              
064347,000515: 21,3460           53742                           DXCH     K2CNTRAL                              
064348,000516: 21,3461           00006                           EXTEND                                         #              THE PRODUCT OF
064349,000517: 21,3462           70001                           MP       L                                     #   1/2                   2       1/2
064350,000518: 21,3463           27742                           ADS      K2CNTRAL   +1                         #  K   *(DEL*OMEGA + ALPHA /(2*K))
064351,000519: 21,3464           54001                           TS       L                                     #                   AND
064352,000520: 21,3465           13467                           TCF      +2                                    #                         2
064353,000521: 21,3466           27741                           ADS      K2CNTRAL                              #   DEL*(DEL*OMEGA + ALPHA /(2*K)) NOW IN
064354,000522:                                                                                                  #  K2CNTRAL
064355,000523: 
064356,000524: 21,3467           31743        DOSHIFT            CA       ININDEX                               
064357,000525: 21,3470           00006                           EXTEND                                         #  MULTIPLY IN THE FACTOR 2(-S), RETURNED
064358,000526: 21,3471           74727                           MP       BIT14                                 #  BY THE GTSQRT SUBROUTINE
064359,000527: 21,3472           27740                           ADS      SHFTFLAG                              
064360,000528: 21,3473           00006                           EXTEND                                         
064361,000529: 21,3474           13513                           BZF      ADDITIN                               
064362,000530: 21,3475           51740                           INDEX    SHFTFLAG                              
064363,000531: 21,3476           34726                           CA       BIT15                                 
064364,000532: 

Page 1481

064366,000534: 21,3477           57741                           XCH      K2CNTRAL                              
064367,000535: 21,3500           00006                           EXTEND                                         
064368,000536: 21,3501           71741                           MP       K2CNTRAL                              
064369,000537: 21,3502           21737                           DAS      K2THETA                               
064370,000538: 21,3503           57741                           XCH      K2CNTRAL                              
064371,000539: 21,3504           00006                           EXTEND                                         
064372,000540: 21,3505           71742                           MP       K2CNTRAL   +1                         
064373,000541: 21,3506           27737                           ADS      K2THETA    +1                         
064374,000542: 21,3507           54001                           TS       L                                     
064375,000543: 21,3510           13512                           TCF      +2                                    
064376,000544: 21,3511           27736                           ADS      K2THETA                               
064377,000545: 
064378,000546: 21,3512           13516                           TCF      NEGUSUM                               
064379,000547: 
064380,000548: 21,3513           00006        ADDITIN            EXTEND                                         
064381,000549: 21,3514           31742                           DCA      K2CNTRAL                              
064382,000550: 21,3515           21737                           DAS      K2THETA                               #  NOW ADD IN THE K2THETA TERM.
064383,000551: 21,3516           11736        NEGUSUM            CCS      K2THETA                               #  TEST SIGN OF HIGH ORDER PART.
064384,000552: 21,3517           13523                           TCF      NEGDRIVE                              
064385,000553: 21,3520           13522                           TCF      +2                                    
064386,000554: 21,3521           13525                           TCF      POSDRIVE                              
064387,000555: 
064388,000556: 21,3522           11737                           CCS      K2THETA    +1                         #  SIGN TEST FOR LOW ORDER PART.
064389,000557: 21,3523           34744        NEGDRIVE           CA       BIT1                                  
064390,000558: 21,3524           13526                           TCF      +2                                    #  STOP GIMBAL DRIVE FOR A ZERO NEGUSUM.
064391,000559: 21,3525           44744        POSDRIVE           CS       BIT1                                  
064392,000560: 21,3526           54001                           TS       L                                     #  SAVE FOR DRIVE REVERSAL TEST.
064393,000561: 21,3527           51747                           INDEX    QRCNTR                                
064394,000562: 21,3530           57501                           XCH      NEGUQ                                 
064395,000563: 
064396,000564: 21,3531           00006                           EXTEND                                         
064397,000565: 21,3532           70001                           MP       L                                     #  MULTIPLY OLD NEGU AND NEW NEGU.
064398,000566: 21,3533           10001                           CCS      L                                     
064399,000567: 21,3534           13551                           TCF      LOUPE                                 #  NON-ZERO GIMBAL DRIVE BEING CONTINUED.
064400,000568: 
064401,000569: 21,3535           13546                           TCF      ZEROLOUP                              #  NO REVERSAL PROBLEM HERE.
064402,000570: 
064403,000571: 21,3536           13540                           TCF      REVERSAL                              #  NON-ZERO GIMBAL DRIVE BEING REVERSED.
064404,000572: 21,3537           13546                           TCF      ZEROLOUP                              #  NO REVERSAL PROBLEM HERE.
064405,000573: 
064406,000574: 21,3540           51747        REVERSAL           INDEX    QRCNTR                                #  A ZERO-DRIVE PAUSE IS NEEDED HERE.  ZERO
064407,000575: 21,3541           55510                           TS       QACCDOT                               #  IS IN A REGISTER FROM CCS ON (-1).
064408,000576: 21,3542           51747                           INDEX    QRCNTR                                
064409,000577: 21,3543           43563                           CS       GMBLBITA                              
064410,000578: 21,3544           00006                           EXTEND                                         
064411,000579: 21,3545           03012                           WAND     CHAN12                                
064412,000580: 
064413,000581: 21,3546           41774        ZEROLOUP           CS       RCSFLAGS                              #  SET UP REQUEST FOR ACDT+C12 CALL.
064414,000582: 21,3547           74740                           MASK     CALLGMBL                              
064415,000583: 21,3550           27774                           ADS      RCSFLAGS                              
064416,000584: 

Page 1482

064418,000586: 21,3551           11747        LOUPE              CCS      QRCNTR                                #  HAVE BOTH AXES BEEN PROCESSED?
064419,000587: 21,3552           13045                           TCF      GOQTRIMG                              #  NO.  DO Q AXIS NEXT.
064420,000588: 
064421,000589: 21,3553           31505                           CA       SAVESR                                #  RESTORE THE SR
064422,000590: 21,3554           54021                           TS       SR                                    
064423,000591: 
064424,000592: 21,3555           00006        GOCLOSE            EXTEND                                         #  TERMINATE THE JASK.
064425,000593: 21,3556           33561                           DCA      CLOSEADR                              
064426,000594: 21,3557           52006                           DTCB                                           
064427,000595: 
064428,000596: 21,3560  E6,1536                                  EBANK=   AOSQ                                  
064429,000597: 21,3560           03270 36106  CLOSEADR           2CADR    CLOSEOUT                              #  TERMINATE THE JASK.
064430,000598: 
064431,000599: 21,3562     5745               TWELVE             EQUALS   OCT14                                 
064432,000600: 21,3562           26501        ROOTHALF           OCTAL    26501                                 #  SQUARE ROOT OF 1/2
064433,000601: 21,3563           01400        GMBLBITA           OCTAL    01400                                 #  INDEXED WRT GMBLBITB   DO NOT MOVE******
064434,000602: 21,3564           11276        OCT11276           OCTAL    11276                                 #  POSMAX - ROOTHALF
064435,000603: 21,3565           06000        GMBLBITB           OCTAL    06000                                 #  INDEXED WRT GMBLBITA   DO NOT MOVE******
064436,000604: 
064437,000605:                                                                                                  #  SUBROUTINE ROOTCYCL:  BY CRAIG WORK,3 APRIL 68
064438,000606:                                                                                                  #  ROOTCYCL IS A SUBROUTINE WHICH EXECUTES ONE NEWTON SQUARE ROOT ALGORITHM ITERATION.  THE INITIAL GUESS AT THE
064439,000607:                                                                                                  #  SQUARE ROOT IS PRESUMED TO BE IN THE A REGISTER AND ONE-HALF THE SQUARE IS TAKEN FROM HALFARG.  THE NEW APPROXI-
064440,000608:                                                                                                  #  MATION TO THE SQUARE ROOT IS RETURNED IN THE A REGISTER.  DEBRIS:   A,L,SR,SCRATCH.  ROOTCYCL IS CALLED FROM
064441,000609:                                                                                                  #  LOCATION (LOC) BY A TC ROOTCYCL, AND RETURNS (TC Q) TO LOC +1.
064442,000610: 
064443,000611:                                                                                                  #  WARNING:  IF THE INITIAL GUESS IS NOT GREATER THAN THE SQUARE, DIVIDE OR ADD OVERFLOW IS A REAL POSSIBILITY.
064444,000612: 
064445,000613: 21,3566           55745        ROOTCYCL           TS       SCRATCH                               #  STORE X
064446,000614: 21,3567           54021                           TS       SR                                    #  X/2 NOW IN SR
064447,000615: 21,3570           31746                           CA       HALFARG                               #  ARG/2 IN THE A REG
064448,000616: 21,3571           22007                           ZL                                             #  PREPARE FOR DIVISION
064449,000617: 21,3572           00006                           EXTEND                                         
064450,000618: 21,3573           11745                           DV       SCRATCH                               #  (ARG/X)/2
064451,000619: 21,3574           60021                           AD       SR                                    #  (X + ARG/X)/2 IN THE A REG
064452,000620: 21,3575           00002                           TC       Q                                     

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