Source Code

These source-code files derive from a printout of Luminary 116 (the Apollo 12 Lunar Module guidance computer program), from the personal library of original AGC developer Don Eyles, digitally photographed at archive.org, financially sponsored by Ron Burkey, 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 116 OF AGC PROGRAM LUMINARY BY NASA 2021112-071
	19:09 AUG. 11,1969
Note that the date is the date of the printout, not the date of the program revision.

020230,000002:                                                                                                  ## Copyright:   Public domain.
020231,000003:                                                                                                  ## Filename:    R60,R62.agc
020232,000004:                                                                                                  ## Purpose:     A section of Luminary revision 116.
020233,000005:                                                                                                  ##              It is part of the source code for the Lunar Module's (LM) 
020234,000006:                                                                                                  ##              Apollo Guidance Computer (AGC) for Apollo 12.
020235,000007:                                                                                                  ##              This file is intended to be a faithful transcription, except
020236,000008:                                                                                                  ##              that the code format has been changed to conform to the
020237,000009:                                                                                                  ##              requirements of the yaYUL assembler rather than the
020238,000010:                                                                                                  ##              original YUL assembler.
020239,000011:                                                                                                  ## Reference:   pp. 474-487
020240,000012:                                                                                                  ## Assembler:   yaYUL
020241,000013:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
020242,000014:                                                                                                  ## Website:     www.ibiblio.org/apollo/index.html
020243,000015:                                                                                                  ## Mod history: 2017-01-22 MAS  Created from Luminary 99.
020244,000016:                                                                                                  ##              2017-01-27 RSB  Back-ported a comment-text fix identified in Luminary 69.
020245,000017:                                                                                                  ##              2017-03-09 RSB  Transcribed, and then proofed comment-text using
020246,000018:                                                                                                  ##                              3-way diff vs Luminary 99 and Luminary 131.
020247,000019:                                                                                                  ##                              (Admittedly, the former is more for detecting errors
020248,000020:                                                                                                  ##                              in Luminary 99 than the other way around.)
020249,000021: 

Page 474

020251,000023:                                                                                                  #  MOD NO: 0                             DATE: 1 MAY 1968
020252,000024:                                                                                                  #  MOD BY: DIGITAL DEVEL GROUP           LOG SECTION R60,R62
020253,000025: 
020254,000026:                                                                                                  #  FUNCTIONAL DESCRIPTION:
020255,000027: 
020256,000028:                                                                                                  #  CALLED AS A GENERAL SUBROUTINE TO MANEUVER THE LM TO A SPECIFIED
020257,000029:                                                                                                  #  ATTITUDE.
020258,000030: 
020259,000031:                                                                                                  #  1. IF THE 3-AXIS FLAG IS NOT SET THE FINAL CDU ANGLES ARE
020260,000032:                                                                                                  #  CALCULATED (VECPOINT).
020261,000033: 
020262,000034:                                                                                                  #  2. THE FDAI BALL ANGLES (NOUN 18) ARE CALCULATED (BALLANGS).
020263,000035: 
020264,000036:                                                                                                  #  3. REQUEST FLASHING DISPLAY V50 N18 PLEASE PERFORM AUTO MANEUVER.
020265,000037: 
020266,000038:                                                                                                  #  4. IF PRIORITY DISPLAY FLAG IS SET DO A PHASECHANGE.  THEN AWAIT
020267,000039:                                                                                                  #  ASTRONAUT RESPONSE.
020268,000040: 
020269,000041:                                                                                                  #  5. DISPLAY RESPONSE RETURNS:
020270,000042: 
020271,000043:                                                                                                  #        A.      ENTER - RESET 3-AXIS FLAG AND RETURN TO CLIENT.
020272,000044: 
020273,000045:                                                                                                  #        B.      TERMINATE - IF IN P00 GO TO STEP 5A.  OTHERWISE CHECK IF R61 IS
020274,000046:                                                                                                  #                THE CALLING PROGRAM.  IF IN R61 AN EXIT IS MADE TO GOTOV56.  IF
020275,000047:                                                                                                  #                NOT IN R61 AN EXIT IS DONE VIA GOTOP00H.
020276,000048: 
020277,000049:                                                                                                  #        C.      PROCEED - CONTINUE WITH PROGRAM AT STEP 6.
020278,000050: 
020279,000051:                                                                                                  #  6. IF THE 3-AXISFLAG IS NOT SET, THE FINAL CDU ANGLES ARE CALCULATED
020280,000052:                                                                                                  #  (VECPOINT).
020281,000053: 
020282,000054:                                                                                                  #  7. THE FDAI BALL ANGLES (NOUN 18) ARE CALCULATED (BALLANGS).
020283,000055: 
020284,000056:                                                                                                  #  8. IF THE G+N SWITCH IS NOT SET GO BACK TO STEP 3.
020285,000057:                                                                                                  #  
020286,000058:                                                                                                  #  9. IF THE AUTO SWITCH IS NOT SET GO BACK TO STEP 3.
020287,000059: 
020288,000060:                                                                                                  #  10. NONFLASHING DISPLAY V06N18 (FDAI ANGLES).
020289,000061: 
020290,000062:                                                                                                  #  11. DO A PHASECHANGE.
020291,000063: 
020292,000064:                                                                                                  #  12. DO A MANEUVER CALCULATION AND ICDU DRIVE ROUTINE TO ACHIEVE FINAL
020293,000065: 
020294,000066:                                                                                                  #  GIMBAL ANGLES (GOMANUR).
020295,000067:                                                                                                  #  13. AT END OF MANEUVER GO TO STEP 3.
020296,000068: 
020297,000069:                                                                                                  #        IF SATISFACTORY MANEUVER STEP 5A EXITS R60.
020298,000070:                                                                                                  #        FOR FURTHER ADJUSTMENT OF THE VEHICLE ATTITUDE ABOUT THE
020299,000071:                                                                                                  #        DESIRED VECTOR, THE ROUTINE MAY BE PERFORMED AGAIN STARTING AT

Page 475

020301,000073:                                                                                                  #        STEP 5C.
020302,000074: 
020303,000075:                                                                                                  #  CALLING SEQUENCE:     TC      BANKCALL
020304,000076:                                                                                                  #                        CADR    R60LEM
020305,000077: 
020306,000078:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:     SCAXIS, POINTVSM (FOR VECPOINT)
020307,000079:                                                                                                  #                                        3AXISFLG.
020308,000080: 
020309,000081:                                                                                                  #  SUBROUTINES CALLED:   VECPOINT, BALLANGS, GOPERF2R, LINUS, GODSPER,
020310,000082:                                                                                                  #                        GOMANUR, DOWNFLAG, PHASCHNG, UPFLAG
020311,000083: 
020312,000084:                                                                                                  #  NORMAL EXIT MODES:    CAE     TEMPR60         (CALLERS RETURN ADDRESS)
020313,000085:                                                                                                  #                        TC      BANKJUMP
020314,000086: 
020315,000087:                                                                                                  #  ALARMS: NONE
020316,000088: 
020317,000089:                                                                                                  #  OUTPUT: NONE
020318,000090: 
020319,000091:                                                                                                  #  DEBRIS: CPHI, CTHETA, CPSI, 3AXISFLG, TBASE2
020320,000092: 
020321,000093: 34,2000                                           BANK     34                                    
020322,000094: 26,2000                                           SETLOC   MANUVER                               
020323,000095: 26,2000                                           BANK                                           
020324,000096: 
020325,000097: 26,2123     1163                                  EBANK=   TEMPR60                               
020326,000098: 
020327,000099: 26,2123                                           COUNT*   $$/R06                                
020328,000100: 26,2123           04645        R60LEM             TC       MAKECADR                              
020329,000101: 26,2124           55163                           TS       TEMPR60                               
020330,000102: 
020331,000103: 26,2125           05504                           TC       UPFLAG                                #  INSURE THAT TOTAL ATTITUDE ERRORS ARE
020332,000104: 26,2126           00013                           ADRES    NEEDLFLG                              #    DISPLAYED ON FDAI ERROR NEEDLES.
020333,000105: 26,2127           05516                           TC       DOWNFLAG                              
020334,000106: 26,2130           00000                           ADRES    NEED2FLG                              
020335,000107: 
020336,000108: 26,2131           34746        REDOMANN           CAF      3AXISBIT                              
020337,000109: 26,2132           70101                           MASK     FLAGWRD5                              #  IS 3-AXIS FLAG SET
020338,000110: 26,2133           10000                           CCS      A                                     
020339,000111: 26,2134           12142                           TCF      TOBALL                                #  YES
020340,000112: 26,2135           06042                           TC       INTPRET                               
020341,000113: 26,2136           77624                           CALL                                           
020342,000114: 26,2137           56040                                    VECPOINT                              #  TO COMPUTE FINAL ANGLES
020343,000115: 26,2140           00322                           STORE    CPHI                                  #  STORE FINAL ANGLES - CPHI, CTHETA, CPSI
020344,000116: 26,2141           77776                           EXIT                                           
020345,000117: 
020346,000118: 26,2142           04616        TOBALL             TC       BANKCALL                              
020347,000119: 26,2143           54272                           CADR     BALLANGS                              #  TO CONVERT ANGLES TO FDAI
020348,000120: 26,2144           32260        TOBALLA            CAF      V06N18                                

Page 476

020350,000122: 26,2145           04616                           TC       BANKCALL                              
020351,000123: 26,2146           20711                           CADR     GOPERF2R                              #  DISPLAY PLEASE PERFORM AUTO MANEUVER
020352,000124: 26,2147           02246                           TC       R61TEST                               
020353,000125: 26,2150           02154                           TC       REDOMANC                              #  PROCEED
020354,000126: 26,2151           02201                           TC       ENDMANU1                              #  ENTER I.E. FINISHED WITH R60
020355,000127: 26,2152           02205                           TC       CHKLINUS                              #  TO CHECK FOR PRIORITY DISPLAYS
020356,000128: 26,2153           05155                           TC       ENDOFJOB                              
020357,000129: 
020358,000130: 26,2154           34746        REDOMANC           CAF      3AXISBIT                              
020359,000131: 26,2155           70101                           MASK     FLAGWRD5                              #  IS 3-AXIS FLAG SET
020360,000132: 26,2156           10000                           CCS      A                                     
020361,000133: 26,2157           12165                           TCF      TOBALLC                               #  YES
020362,000134: 26,2160           06042                           TC       INTPRET                               
020363,000135: 26,2161           77624                           CALL                                           
020364,000136: 26,2162           56040                                    VECPOINT                              #  TO COMPUTE FINAL ANGLES
020365,000137: 26,2163           00322                           STORE    CPHI                                  #  STORE ANGLES
020366,000138: 26,2164           77776                           EXIT                                           
020367,000139: 
020368,000140: 26,2165           04616        TOBALLC            TC       BANKCALL                              
020369,000141: 26,2166           54272                           CADR     BALLANGS                              #  TO CONVERT ANGLES TO FDAI
020370,000142: 26,2167           02261                           TC       G+N,AUTO                              #  CHECK AUTO MODE
020371,000143: 26,2170           10000                           CCS      A                                     
020372,000144: 26,2171           12144                           TCF      TOBALLA                               #  NOT AUTO, GO REREQUEST AUTO MANEUVER.
020373,000145: 
020374,000146: 26,2172           32260        AUTOMANV           CAF      V06N18                                #  STATIC DISPLAY DURING AUTO MANEUVER
020375,000147: 26,2173           04616                           TC       BANKCALL                              #                                        -
020376,000148: 26,2174           20452                           CADR     GODSPR                                #                                        -
020377,000149: 26,2175           02205                           TC       CHKLINUS                              #  TO CHECK FOR PRIORITY DISPLAYS
020378,000150: 
020379,000151: 26,2176           04616        STARTMNV           TC       BANKCALL                              #  PERFORM MANEUVER VIA KALCMANU
020380,000152: 26,2177           17742                           CADR     GOMANUR                               
020381,000153: 
020382,000154: 26,2200           12144        ENDMANUV           TCF      TOBALLA                               #  FINISHED MANEUVER.
020383,000155: 26,2201           05516        ENDMANU1           TC       DOWNFLAG                              #  RESET 3-AXIS FLAG
020384,000156: 26,2202           00124                           ADRES    3AXISFLG                              
020385,000157: 26,2203           31163                           CAE      TEMPR60                               #                                        -
020386,000158: 26,2204           04640                           TC       BANKJUMP                              #                                        -
020387,000159: 
020388,000160: 26,2205           40100        CHKLINUS           CS       FLAGWRD4                              
020389,000161: 26,2206           74740                           MASK     PDSPFBIT                              #  IS PRIORITY DISPLAY FLAG SET?
020390,000162: 26,2207           10000                           CCS      A                                     #                                        -
020391,000163: 26,2210           00002                           TC       Q                                     #  NO - EXIT
020392,000164: 26,2211           30002                           CA       Q                                     
020393,000165: 26,2212           54156                           TS       MPAC       +2                         #  SAVE RETURN
020394,000166: 26,2213           46250                           CS       THREE                                 #  OBTAIN LOCATION FOR RESTART
020395,000167: 26,2214           60133                           AD       BUF2                                  #  HOLDS Q OF LAST DISPLAY
020396,000168: 26,2215           55054                           TS       TBASE2                                
020397,000169: 
020398,000170: 26,2216           05353                           TC       PHASCHNG                              
020399,000171: 26,2217           00132                           OCT      00132                                 

Page 477

020401,000173: 
020402,000174: 26,2220           34745                           CAF      BIT7                                  
020403,000175: 26,2221           05464                           TC       LINUS                                 #  GO SET BITS FOR PRIORITY DISPLAY      -
020404,000176: 26,2222           00156                           TC       MPAC       +2                         
020405,000177: 
020406,000178: 26,2223           37717        RELINUS            CAF      PRIO26                                #  RESTORE ORIGINAL PRIORITY
020407,000179: 26,2224           05146                           TC       PRIOCHNG                              
020408,000180: 
020409,000181: 26,2225           34747                           CAF      TRACKBIT                              #  DON'T CONTINUE R60 UNLESS TRACKFLAG ON.
020410,000182: 26,2226           70075                           MASK     FLAGWRD1                              
020411,000183: 26,2227           10000                           CCS      A                                     
020412,000184: 26,2230           12243                           TCF      RER60                                 
020413,000185: 
020414,000186: 26,2231           34745                           CAF      RNDVZBIT                              #  IS IT P20?
020415,000187: 26,2232           70074                           MASK     FLAGWRD0                              
020416,000188: 26,2233           10000                           CCS      A                                     
020417,000189: 26,2234           02240                           TC       +4                                    #  YES
020418,000190: 26,2235           05353                           TC       PHASCHNG                              #  NO, MUST BE P25, SET 2.11 SPOT
020419,000191: 26,2236           40112                           OCT      40112                                 
020420,000192: 
020421,000193: 26,2237           05155                           TC       ENDOFJOB                              
020422,000194: 
020423,000195: 26,2240           05353                           TC       PHASCHNG                              #  SET 2.7 SPOT FOR P20
020424,000196: 26,2241           40072                           OCT      40072                                 
020425,000197: 
020426,000198: 26,2242           05155                           TC       ENDOFJOB                              
020427,000199: 
020428,000200: 26,2243           05504        RER60              TC       UPFLAG                                #  SET PRIO DISPLAY FLAG AFTER RESTART
020429,000201: 26,2244           00077                           ADRES    PDSPFLAG                              
020430,000202: 
020431,000203: 26,2245           01054                           TC       TBASE2                                
020432,000204: 
020433,000205: 26,2246           31010        R61TEST            CA       MODREG                                #  IF WE ARE IN P00 IT MUST BE V49 OR V89
020434,000206: 26,2247           00006                           EXTEND                                         
020435,000207: 26,2250           12201                           BZF      ENDMANU1                              #  THUS WE GO TO ENDEXT VIA USER
020436,000208: 
020437,000209: 26,2251           30100                           CA       FLAGWRD4                              #  ARE WE IN R61 (P20 OR P25)
020438,000210: 26,2252           74740                           MASK     PDSPFBIT                              
020439,000211: 26,2253           00006                           EXTEND                                         
020440,000212: 26,2254           16001                           BZF      GOTOPOOH                              #  NO
020441,000213: 26,2255           06025                           TC       GOTOV56                               #  YES
020442,000214: 
020443,000215: 26,2256           20100        BIT14+7            OCT      20100                                 #                                        -                    
020444,000216: 26,2257           00203        OCT203             OCT      203                                   
020445,000217: 26,2260           01422        V06N18             VN       0618                                  
020446,000218:                                                                                                  #  SUBROUTINE TO CHECK FOR G+N CONTROL, AUTO STABILIZATION
020447,000219: 
020448,000220:                                                                                                  #  RETURNS WITH C(A) = +         IF NOT SET FOR G+N, AUTO
020449,000221:                                                                                                  #  RETURNS WITH C(A) = +0        IF SWITCHES ARE SET
020450,000222: 
020451,000223: 26,2261           00006        G+N,AUTO           EXTEND                                         

Page 478

020453,000225: 26,2262           00030                           READ     CHAN30                                
020454,000226: 26,2263           74742                           MASK     BIT10                                 
020455,000227: 26,2264           10000                           CCS      A                                     
020456,000228: 26,2265           00002                           TC       Q                                     #  NOT IN G+N    C(A) = +
020457,000229: 26,2266           00006        ISITAUTO           EXTEND                                         #  CHECK FOR AUTO MODE
020458,000230: 26,2267           00031                           READ     CHAN31                                
020459,000231: 26,2270           74736                           MASK     BIT14                                 
020460,000232: 26,2271           00002                           TC       Q                                     #  (+) = NOT IN AUTO, (+0) = AOK
020461,000233: 

Page 479

020463,000235:                                                                                                  #  PROGRAM DESCRIPTION BALLANGS
020464,000236:                                                                                                  #  MOD NO.                               LOG SECTION R60,R62
020465,000237: 
020466,000238:                                                                                                  #  WRITTEN BY RAMA M. AIYAWAR
020467,000239: 
020468,000240:                                                                                                  #  FUNCTIONAL DESCRIPTION
020469,000241: 
020470,000242:                                                                                                  #        COMPUTES LM FDAI BALL DISPLAY ANGLES
020471,000243: 
020472,000244:                                                                                                  #  CALLING SEQUENCE
020473,000245: 
020474,000246:                                                                                                  #        TC      BALLANGS
020475,000247: 
020476,000248:                                                                                                  #  NORMAL EXIT MODE
020477,000249: 
020478,000250:                                                                                                  #        TC      BALLEXIT        (SAVED Q)
020479,000251: 
020480,000252:                                                                                                  #  ALARM OR EXIT MODE    NIL
020481,000253: 
020482,000254:                                                                                                  #  SUBROUTINES CALLED
020483,000255: 
020484,000256:                                                                                                  #        CD*TR*G
020485,000257:                                                                                                  #        ARCTAN
020486,000258: 
020487,000259:                                                                                                  #  INPUT
020488,000260: 
020489,000261:                                                                                                  #        CPHI,CTHETA,CPSI ARE THE ANGLES CORRESPONDING TO AOG, AIG, AMG.  THEY ARE
020490,000262:                                                                                                  #        SP,2S COMPLIMENT SCALED TO HALF REVOLUTION.
020491,000263: 
020492,000264:                                                                                                  #  OUTPUT
020493,000265: 
020494,000266:                                                                                                  #        FDAIX, FDAIY, FDAIZ ARE THE REQUIRED BALL ANGLES SCALED TO HALF REVOLUTION
020495,000267:                                                                                                  #        SP,2S COMPLIMENT.
020496,000268: 
020497,000269:                                                                                                  #        THESE ANGLES WILL BE DISPLAYED AS DEGREES AND HUNDREDTHS, IN THE ORDER ROLL, PITCH, YAW, USING NOUNS 18 & 19.
020498,000270: 
020499,000271:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED
020500,000272: 
020501,000273:                                                                                                  #        CPHI, CTHETA, CPSI      EACH A SP REGISTER
020502,000274: 
020503,000275:                                                                                                  #  DEBRIS
020504,000276: 
020505,000277:                                                                                                  #        A,L,Q,MPAC,SINCDU,COSCDU,PUSHLIST,BALLEXIT
020506,000278: 
020507,000279:                                                                                                  #  NOMENCLATURE: CPHI, CTHETA, & CPSI REPRESENT THE OUTER, INNER, & MIDDLE GIMBAL ANGLES, RESPECTIVELY; OR
020508,000280:                                                                                                  #                EQUIVALENTLY, CDUX, CDUY, & CDUZ.
020509,000281: 
020510,000282:                                                                                                  #  NOTE:  ARCTAN CHECKS FOR OVERFLOW AND SHOULD BE ABLE TO HANDLE ANY SINGULARITIES.
020511,000283: 
020512,000284: 26,2000                                           SETLOC   BAWLANGS                              
020513,000285: 26,2000                                           BANK                                           
020514,000286: 
020515,000287: 26,2272                                           COUNT*   $$/BALL                               
020516,000288: 26,2272           04645        BALLANGS           TC       MAKECADR                              
020517,000289: 26,2273           55337                           TS       BALLEXIT                              
020518,000290: 26,2274           30321                           CA       CPHI                                  

Page 480

020520,000292: 26,2275           54771                           TS       CDUSPOT    +4                         
020521,000293: 26,2276           30322                           CA       CTHETA                                
020522,000294: 26,2277           54765                           TS       CDUSPOT                               
020523,000295: 26,2300           30323                           CA       CPSI                                  
020524,000296: 26,2301           54767                           TS       CDUSPOT    +2                         
020525,000297: 
020526,000298: 26,2302           06042                           TC       INTPRET                               
020527,000299: 26,2303           45001                           SETPD    CALL                                  
020528,000300: 26,2304           00001                                    0D                                    
020529,000301: 26,2305           47545                                    CD*TR*G                               
020530,000302: 
020531,000303: 26,2306           41345                           DLOAD    DMP                                   
020532,000304: 26,2307           00742                                    SINCDUX                               #  SIN (OGA)
020533,000305: 26,2310           00746                                    COSCDUZ                               #  COS (MGA)
020534,000306: 
020535,000307: 26,2311           57552                           SL1      DCOMP                                 #  SCALE
020536,000308: 26,2312           65336                           ARCSIN   PDDL                                  #  YAW = ARCSIN(-SXCZ) INTO 0 PD
020537,000309: 26,2313           00740                                    SINCDUZ                               
020538,000310: 26,2314           14023                           STODL    SINTH                                 #  (SINTH = 18D IN PD)
020539,000311: 26,2315           00746                                    COSCDUZ                               
020540,000312: 26,2316           72405                           DMP      SL1                                   #  RESCALE
020541,000313: 26,2317           00750                                    COSCDUX                               
020542,000314: 26,2320           34021                           STCALL   COSTH                                 #  (COSTH = 16D IN PD)
020543,000315: 26,2321           26510                                    ARCTAN                                
020544,000316: 26,2322           41325                           PDDL     DMP                                   #  ROLL = ARCTAN(SZ/CZCX) INTO 2 PD
020545,000317: 26,2323           00740                                    SINCDUZ                               
020546,000318: 26,2324           00742                                    SINCDUX                               
020547,000319: 26,2325           41512                           SL2      PUSH                                  #  SXSZ INTO 4 PD
020548,000320: 26,2326           65205                           DMP      PDDL                                  #  SXSZCY INTO 4 PD
020549,000321: 26,2327           00744                                    COSCDUY                               
020550,000322: 26,2330           65205                           DMP      PDDL                                  #  SXSZSY INTO 6 PD
020551,000323: 26,2331           00736                                    SINCDUY                               
020552,000324: 26,2332           00750                                    COSCDUX                               
020553,000325: 26,2333           72405                           DMP      SL1                                   #  CXCY
020554,000326: 26,2334           00744                                    COSCDUY                               
020555,000327: 26,2335           45425                           DSU      STADR                                 #  PULL UP FROM 6 PD
020556,000328: 26,2336           63756                           STODL    COSTH                                 #  COSTH = CXCY - SXSZSY
020557,000329: 26,2337           00736                                    SINCDUY                               
020558,000330: 26,2340           72405                           DMP      SL1                                   
020559,000331: 26,2341           00750                                    COSCDUX                               #  CXSY
020560,000332: 26,2342           45415                           DAD      STADR                                 #  PULL UP FROM 4 PD
020561,000333: 26,2343           43754                           STCALL   SINTH                                 #  SINTH = CXSY + SXSZCY
020562,000334: 26,2344           26510                                    ARCTAN                                #  RETURNS WITH D(MPAC) = PITCH
020563,000335: 26,2345           55525                           PDDL     VDEF                                  #  PITCH INTO 2 PD, ROLL INTO MPAC FROM 2 PD
020564,000336: 26,2346           77634                           RTB                                            #  VDEF MAKES V(MPAC) = ROLL, PITCH, YAW
020565,000337: 26,2347           21621                                    V1STO2S                               
020566,000338: 26,2350           02345                           STORE    FDAIX                                 #  MODE IS TP
020567,000339: 26,2351           77776                           EXIT                                           
020568,000340: 
020569,000341: 26,2352           31337        ENDBALL            CA       BALLEXIT                              
020570,000342: 

Page 481

020572,000344: 26,2353           04640                           TC       BANKJUMP                              
020573,000345: 

Page 482

020575,000347:                                                                                                  #  PROGRAM DESCRIPTION - VECPOINT
020576,000348: 
020577,000349:                                                                                                  #  THIS INTERPRETIVE SUBROUTINE MAY BE USED TO POINT A SPACECRAFT AXIS IN A DESIRED DIRECTION.  THE AXIS
020578,000350:                                                                                                  #  TO BE POINTED MUST APPEAR AS A HALF UNIT DOUBLE PRECISION VECTOR IN SUCCESSIVE LOCATIONS OF ERASABLE MEMORY
020579,000351:                                                                                                  #  BEGINNING WITH THE LOCATION CALLED SCAXIS.  THE COMPONENTS OF THIS VECTOR ARE GIVEN IN SPACECRAFT COORDINATES.
020580,000352:                                                                                                  #  THE DIRECTION IN WHICH THIS AXIS IS TO BE POINTED MUST APPEAR AS A HALF UNIT DOUBLE PRECISION VECTOR IN
020581,000353:                                                                                                  #  SUCCESSIVE LOCATIONS OF ERASABLE MEMORY BEGINNING WITH THE ADDRESS CALLED POINTVSM.  THE COMPONENTS OF THIS
020582,000354:                                                                                                  #  VECTOR ARE GIVEN IN STABLE MEMBER COORDINATES.  WITH THIS INFORMATION VECPOINT COMPUTES A SET OF THREE GIMBAL
020583,000355:                                                                                                  #  ANGLES (2S COMPLEMENT) CORESPONDING TO THE CROSS-PRODUCT ROTATION BETWE EN SCAXIS AND POINTVSM AND STORES THEM
020584,000356:                                                                                                  #  IN T(MPAC) BEFORE RETURNING TO THE CALLER.
020585,000357: 
020586,000358:                                                                                                  #  THIS ROTATION, HOWEVER, MAY BRING THE S/C INTO GIMBAL LOCK.  WHEN POINTING A VECTOR IN THE Y-Z PLANE,
020587,000359:                                                                                                  #  THE TRANSPONDER AXIS, OR THE AOT FOR THE LEM, THE PROGRAM WILL CORRECT THIS PROBLEM BY ROTATING THE CROSS-
020588,000360:                                                                                                  #  PRODUCT ATTITUDE ABOUT POINTVSM BY A FIXED AMOUNT SUFFICIENT TO ROTATE THE DESIRED S/C ATTITUDE OUT OF GIMBAL
020589,000361:                                                                                                  #  LOCK.  IF THE AXIS TO BE POINTED IS MORE THAN 40.6 DEGREES BUT LESS THAN 60.5 DEG FROM THE +X (OR -X) AXIS,
020590,000362:                                                                                                  #  THE ADDITIONAL ROTATION TO AVOID GIMAL LOCK IS 35 DEGREES.  IF THE AXIS IS MORE THAN 60.5 DEGEES FROM +X (OR -X)
020591,000363:                                                                                                  #  THE ADDITIONAL ROTATION IS 35 DEGREES.  THE GIMBAL ANGLES CORRESPONDING TO THIS ATTITUDE ARE THEN COMPUTED AND
020592,000364:                                                                                                  #  STORED AS 2S COMPLIMENT ANGLES IN T(MPAC) BEFORE RETURNING TO THE CALLER.
020593,000365: 
020594,000366:                                                                                                  #  WHEN POINTING THE X-AXIS, OR THE THRUST VECTOR, OR ANY VECTOR WITHIN 40.6 DEG OF THE X-AXIS, VECPOINT
020595,000367:                                                                                                  #  CANNOT CORRECT FOR A CROSS-PRODUCT ROTATION INTO GIMBAL LOCK.  IN THIS CASE A PLATFORM REALIGNMENT WOULD BE
020596,000368:                                                                                                  #  REQUIRED TO POINT THE VECTOR IN THE DESIRED DIRECTION.  AT PRESENT NO INDICATION IS GIVEN FOR THIS SITUATION
020597,000369:                                                                                                  #  EXCEPT THAT THE FINAL MIDDLE GIMBAL ANGLE IN MPAC +2 IS GREATER THAN 59 DEGREES.
020598,000370: 
020599,000371:                                                                                                  #  CALLING SEQUENCE -
020600,000372: 
020601,000373:                                                                                                  #        1)      LOAD SCAXIS, POINTVSM
020602,000374:                                                                                                  #        2)      CALL
020603,000375:                                                                                                  #                        VECPOINT
020604,000376: 
020605,000377:                                                                                                  #  RETURNS WITH
020606,000378: 
020607,000379:                                                                                                  #        1)      DESIRED OUTER GIMBAL ANGLE IN MPAC
020608,000380:                                                                                                  #        2)      DESIRED INNER GIMBAL ANGLE IN MPAC +1
020609,000381:                                                                                                  #        3)      DESIRED MIDDLE GIMBAL ANGLE IN MPAC +2
020610,000382: 
020611,000383:                                                                                                  #  ERASABLES USED -
020612,000384: 
020613,000385:                                                                                                  #        1)      SCAXIS          6
020614,000386:                                                                                                  #        2)      POINTVSM        6
020615,000387:                                                                                                  #        3)      MIS             18
020616,000388:                                                                                                  #        4)      DEL             18
020617,000389:                                                                                                  #        5)      COF             6
020618,000390:                                                                                                  #        6)      VECQTEMP        1
020619,000391:                                                                                                  #        7)      ALL OF VAC AREA 43
020620,000392: 
020621,000393:                                                                                                  #                        TOTAL   99
020622,000394: 
020623,000395: 27,2000                                           SETLOC   VECPT                                 
020624,000396: 27,2000                                           BANK                                           

Page 483

020626,000398: 27,2032                                           COUNT*   $$/VECPT                              
020627,000399: 
020628,000400: 27,2032  E6,1676                                  EBANK=   BCDU                                  
020629,000401: 
020630,000402: 27,2032           40020        VECPNT1            STQ      BOV                                   #  THIS ENTRY USES DESIRED CDUS
020631,000403: 27,2033           03325                                    VECQTEMP                              #  NOT PRESENT - ENTER WITH CDUD'S IN MPAC
020632,000404: 27,2034           56035                                    VECPNT2                               
020633,000405: 27,2035           52164        VECPNT2            AXC,2    GOTO                                  
020634,000406: 27,2036           03246                                    MIS                                   
020635,000407: 27,2037           56046                                    STORANG                               
020636,000408: 27,2040           40020        VECPOINT           STQ      BOV                                   #  SAVE RETURN ADDRESS
020637,000409: 27,2041           03325                                    VECQTEMP                              
020638,000410: 27,2042           56043                                    VECLEAR                               #  AND CLEAR OVFIND
020639,000411: 27,2043           47164        VECLEAR            AXC,2    RTB                                   
020640,000412: 27,2044           03246                                    MIS                                   #  READ THE PRESENT CDU ANGLES AND
020641,000413: 27,2045           44403                                    READCDUK                              #  STORE THEM IN PD25, 26, 27
020642,000414: 27,2046           34032        STORANG            STCALL   25D                                   
020643,000415: 27,2047           44410                                    CDUTODCM                              #  S/C AXES TO STABLE MEMBER AXES (MIS)
020644,000416: 27,2050           61375                           VLOAD    VXM                                   
020645,000417: 27,2051           03773                                    POINTVSM                              #  RESOLVE THE POINTING DIRECTION VF INTO
020646,000418: 27,2052           03247                                    MIS                                   #  INITIAL S/C AXES (VF = POINTVSM)
020647,000419: 27,2053           77656                           UNIT                                           
020648,000420: 27,2054           00035                           STORE    28D                                   
020649,000421:                                                                                                  #  PD 28 29 30 31 32 33
020650,000422: 27,2055           53435                           VXV      UNIT                                  #  TAKE THE CROSS PRODUCT VF X VI
020651,000423: 27,2056           03765                                    SCAXIS                                #  WHERE VI = SCAXIS
020652,000424: 27,2057           57400                           BOV      VCOMP                                 
020653,000425: 27,2060           56170                                    PICKAXIS                              
020654,000426: 27,2061           17271                           STODL    COF                                   #  CHECK MAGNITUDE
020655,000427: 27,2062           00045                                    36D                                   #  OF CROSS PRODUCT
020656,000428: 27,2063           50025                           DSU      BMN                                   #  VECTOR, IF LESS
020657,000429: 27,2064           14415                                    DPB-14                                #  THAN B-14 ASSUME
020658,000430: 27,2065           56170                                    PICKAXIS                              #  UNIT OPERATION
020659,000431: 27,2066           50375                           VLOAD    DOT                                   #  INVALID.
020660,000432: 27,2067           03765                                    SCAXIS                                
020661,000433: 27,2070           00035                                    28D                                   
020662,000434: 27,2071           65552                           SL1      ARCCOS                                
020663,000435: 27,2072           77624        COMPMATX           CALL                                           #  NOW COMPUTE THE TRANSFORMATION FROM
020664,000436: 27,2073           44527                                    DELCOMP                               #  FINAL S/C AXES TO INITIAL S/C AXES MFI
020665,000437: 27,2074           75160                           AXC,1    AXC,2                                 
020666,000438: 27,2075           03246                                    MIS                                   #  COMPUTE THE TRANSFORMATION FROM FINAL
020667,000439: 27,2076           02230                                    KEL                                   #  S/C AXES TO STABLE MEMBER AXES
020668,000440: 27,2077           77624                           CALL                                           #  MFS = MIS MFI
020669,000441: 27,2100           44312                                    MXM3                                  #  (IN PD LIST)
020670,000442: 
020671,000443: 27,2101           51545                           DLOAD    ABS                                   
020672,000444: 27,2102           00007                                    6                                     #  MFS6 = SIN(CPSI)                      $2
020673,000445: 27,2103           50025                           DSU      BMN                                   
020674,000446: 27,2104           14402                                    SINGIMLC                              #  = SIN(59 DEGS)                        $2
020675,000447: 27,2105           56160                                    FINDGIMB                              #  /CPSI/ LESS THAN 59 DEGS

Page 484

020677,000449:                                                                                                  #  I.E. DESIRED ATTITUDE NOT IN GIMBAL LOCK
020678,000450: 
020679,000451: 27,2106           51545                           DLOAD    ABS                                   #  CHECK TO SEE IF WE ARE POINTING
020680,000452: 27,2107           03765                                    SCAXIS                                #  THE THRUST AXIS
020681,000453: 27,2110           51025                           DSU      BPL                                   
020682,000454: 27,2111           14404                                    SINVEC1                               #  SIN 49.4 DEGS                         $2
020683,000455: 27,2112           56160                                    FINDGIMB                              #  IF SO, WE ARE TRYING TO POINT IT INTO
020684,000456: 27,2113           77775                           VLOAD                                          #  GIMBAL LOCK, ABORT COULD GO HERE
020685,000457: 27,2114           77626                           STADR                                          
020686,000458: 27,2115           50514                           STOVL    MIS        +12D                       
020687,000459: 27,2116           77626                           STADR                                          #  STORE MFS (IN PD LIST) IN MIS
020688,000460: 27,2117           50522                           STOVL    MIS        +6                         
020689,000461: 27,2120           77626                           STADR                                          
020690,000462: 27,2121           50530                           STOVL    MIS                                   
020691,000463: 27,2122           03255                                    MIS        +6                         #  INNER GIMBAL AXIS IN FINAL S/C AXES
020692,000464: 27,2123           57444                           BPL      VCOMP                                 #  LOCATE THE IG AXIS DIRECTION CLOSEST TO
020693,000465: 27,2124           56125                                    IGSAMEX                               #  FINAL X S/C AXIS
020694,000466: 
020695,000467: 27,2125           50035        IGSAMEX            VXV      BMN                                   #  FIND THE SHORTEST WAY OF ROTATING THE 
020696,000468: 27,2126           03765                                    SCAXIS                                #  S/C OUT OF GIMBAL LOCK BY A ROTATION 
020697,000469: 27,2127           56134                                    U=SCAXIS                              #  ABOUT +- SCAXIS, I.E. IF  (IG (SGN MFS3)
020698,000470:                                                                                                  #  X SCAXIS . XF) LESS THAN 0, U = SCAXIS
020699,000471:                                                                                                  #  OTHERWISE U = -SCAXIS
020700,000472: 
020701,000473: 27,2130           57575                           VLOAD    VCOMP                                 
020702,000474: 27,2131           03765                                    SCAXIS                                
020703,000475: 27,2132           37271                           STCALL   COF                                   #  ROTATE ABOUT -SCAXIS
020704,000476: 27,2133           56137                                    CHEKAXIS                              
020705,000477: 27,2134           77775        U=SCAXIS           VLOAD                                          
020706,000478: 27,2135           03765                                    SCAXIS                                
020707,000479: 27,2136           03271                           STORE    COF                                   #  ROTATE ABOUT + SCAXIS
020708,000480: 27,2137           51545        CHEKAXIS           DLOAD    ABS                                   
020709,000481: 27,2140           03765                                    SCAXIS                                #  SEE IF WE ARE POINTING THE AOT
020710,000482: 27,2141           51025                           DSU      BPL                                   
020711,000483: 27,2142           14406                                    SINVEC2                               #  SIN 29.5 DEGS                         $2
020712,000484: 27,2143           56147                                    PICKANG1                              #  IF SO, ROTATE 50 DEGS ABOUT +- SCAXIS
020713,000485: 27,2144           52145                           DLOAD    GOTO                                  #  IF NOT, MUST BE POINTING THE TRANSPONDER
020714,000486: 27,2145           14412                                    VECANG2                               #  OR SOME VECTOR IN THE Y, OR Z PLANE
020715,000487: 27,2146           56151                                    COMPMFSN                              #  IN THIS CASE ROTATE 35 DEGS TO GET OUT
020716,000488:                                                                                                  #  OF GIMBAL LOCK (VECANG2  $360)
020717,000489: 27,2147           77745        PICKANG1           DLOAD                                          
020718,000490: 27,2150           14410                                    VECANG1                               #  = 50 DEGS                             $360
020719,000491: 27,2151           77624        COMPMFSN           CALL                                           
020720,000492: 27,2152           44527                                    DELCOMP                               #  COMPUTE THE ROTATION ABOUT SCAXIS TO
020721,000493: 27,2153           75160                           AXC,1    AXC,2                                 #  BRING MFS OUT OF GIMBAL LOCK
020722,000494: 27,2154           03246                                    MIS                                   
020723,000495: 27,2155           02230                                    KEL                                   
020724,000496: 27,2156           77624                           CALL                                           #  COMPUTE THE NEW TRANSFORMATION FROM
020725,000497: 27,2157           44312                                    MXM3                                  #  DESIRED S/C AXES TO STABLE MEMBER AXES
020726,000498:                                                                                                  #  WHICH WILL ALIGN VI WITH VF AND AVOID

Page 485

020728,000500:                                                                                                  #  GIMBAL LOCK
020729,000501: 27,2160           45160        FINDGIMB           AXC,1    CALL                                  
020730,000502: 27,2161           00000                                    0                                     #  EXTRACT THE COMMANDED CDU ANGLES FROM
020731,000503: 27,2162           44654                                    DCMTOCDU                              #  THIS MATRIX
020732,000504: 27,2163           40234                           RTB      SETPD                                 
020733,000505: 27,2164           21621                                    V1STO2S                               #  CONVERT TO 2:S COMPLEMENT
020734,000506: 27,2165           00001                                    0                                     
020735,000507: 27,2166           77650                           GOTO                                           
020736,000508: 27,2167           03325                                    VECQTEMP                              #  RETURN TO CALLER
020737,000509: 
020738,000510: 27,2170           50375        PICKAXIS           VLOAD    DOT                                   #  IF VF X VI = 0, FIND VF . VI
020739,000511: 27,2171           00035                                    28D                                   
020740,000512: 27,2172           03765                                    SCAXIS                                
020741,000513: 27,2173           72240                           BMN      TLOAD                                 
020742,000514: 27,2174           54354                                    ROT180                                
020743,000515: 27,2175           00032                                    25D                                   
020744,000516: 27,2176           77650                           GOTO                                           #  IF VF = VI, CDU DESIRED = PRESENT CDU
020745,000517: 27,2177           03325                                    VECQTEMP                              #  PRESENT CDU ANGLES
020746,000518: 
020747,000519: 35,2000                                           BANK     35                                    
020748,000520: 26,2000                                           SETLOC   MANUVER1                              
020749,000521: 26,2000                                           BANK                                           
020750,000522: 26,2354           47375        ROT180             VLOAD    VXV                                   #  IF VF, VI ANTIPARALLEL, 108 DEG ROTATION
020751,000523: 26,2355           03255                                    MIS        +6                         #  IS REQUIRED.  Y STABLE MEMBER AXIS IN
020752,000524: 26,2356           06522                                    HIDPHALF                              #  INITIAL S/C AXES.
020753,000525: 26,2357           47256                           UNIT     VXV                                   #  FIND Y(SM) X X(I)
020754,000526: 26,2360           03765                                    SCAXIS                                #  FIND UNIT(VI X UNIT(Y(SM) X X(I)))
020755,000527: 26,2361           40056                           UNIT     BOV                                   #  I.E. PICK A VECTOR IN THE PLANE OF X(I),
020756,000528: 26,2362           54376                                    PICKX                                 #  Y(SM) PERPENDICULAR TO VI
020757,000529: 26,2363           17271                           STODL    COF                                   
020758,000530: 26,2364           00045                                    36D                                   #  CHECK MAGNITUDE
020759,000531: 26,2365           50025                           DSU      BMN                                   #  OF THIS VECTOR.
020760,000532: 26,2366           14415                                    DPB-14                                #  IF LESS THAN B-14,
020761,000533: 26,2367           54376                                    PICKX                                 #  PICK X-AXIS.
020762,000534: 26,2370           77775                           VLOAD                                          
020763,000535: 26,2371           03271                                    COF                                   
020764,000536: 26,2372           17271        XROT               STODL    COF                                   
020765,000537: 26,2373           06522                                    HIDPHALF                              
020766,000538: 26,2374           77650                           GOTO                                           
020767,000539: 26,2375           56072                                    COMPMATX                              
020768,000540: 26,2376           52175        PICKX              VLOAD    GOTO                                  #  PICK THE XAXIS IN THIS CASE
020769,000541: 26,2377           06522                                    HIDPHALF                              
020770,000542: 26,2400           54372                                    XROT                                  
020771,000543: 26,2401           15555 35172  SINGIMLC           2DEC     .4285836003                            #  = SIN(59)                             $2
020772,000544: 
020773,000545: 26,2403           14113 36326  SINVEC1            2DEC     .3796356537                            #  = SIN(49.4)                           $2
020774,000546: 
020775,000547: 26,2405           07701 35703  SINVEC2            2DEC     .2462117800                            #  = SIN(29.5)                           $2
020776,000548: 
020777,000549: 26,2407           04343 21616  VECANG1            2DEC     .1388888889                            #  = 50 DEGREES                          $360

Page 486

020779,000551: 26,2411           03070 34344  VECANG2            2DEC     .09722222222                            #  = 35 DEGREES                          $360
020780,000552: 
020781,000553: 26,2413           00000        1BITDP             OCT      0                                     #  KEEP THIS BEFORE DPB(-14)        *********
020782,000554: 26,2414           00001        DPB-14             OCT      00001                                 
020783,000555: 26,2415           00000                           OCT      00000                                 
020784,000556: 

Page 487

020786,000558:                                                                                                  #  ROUTINE FOR INITIATING AUTOMATIC MANEUVER VIA KEYBOARD (V49)
020787,000559: 
020788,000560: 34,2000                                           BANK     34                                    
020789,000561: 23,2000                                           SETLOC   R62                                   
020790,000562: 23,2000                                           BANK                                           
020791,000563: 23,2103  E6,1676                                  EBANK=   BCDU                                  
020792,000564: 
020793,000565: 23,2103                                           COUNT*   $$/R62                                
020794,000566: 
020795,000567: 23,2103  23,2103               R62DISP            EQUALS   R62FLASH                              
020796,000568: 
020797,000569: 23,2103           35010        R62FLASH           CAF      V06N22                                #  FLASH V06N22 AND
020798,000570: 23,2104           04616                           TC       BANKCALL                              #  ICDU ANGLES
020799,000571: 23,2105           20477                           CADR     GOFLASH                               
020800,000572: 23,2106           15472                           TCF      ENDEXT                                #  TERMINATE
020801,000573: 23,2107           12111                           TCF      GOMOVE                                #  PROCEED
020802,000574: 23,2110           12103                           TCF      R62FLASH                              #  ENTER
020803,000575: 
020804,000576:                                                                                                  #  ASTRONAUT MAY LOAD NEW ICDUS AT THIS
020805,000577:                                                                                                  #  POINT
020806,000578: 23,2111           05504        GOMOVE             TC       UPFLAG                                #  SET FOR 3-AXIS MANEUVER
020807,000579: 23,2112           00124                           ADRES    3AXISFLG                              
020808,000580: 
020809,000581: 23,2113           04616                           TC       BANKCALL                              
020810,000582: 23,2114           54123                           CADR     R60LEM                                
020811,000583: 23,2115           15472                           TCF      ENDEXT                                #  END R62
020812,000584: 

End of include-file R60,R62.agc.  Parent file is MAIN.agc