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.

020232,000002:                                                                                                  ## Copyright:   Public domain.
020233,000003:                                                                                                  ## Filename:    R60,R62.agc
020234,000004:                                                                                                  ## Purpose:     A section of Luminary revision 116.
020235,000005:                                                                                                  ##              It is part of the source code for the Lunar Module's (LM) 
020236,000006:                                                                                                  ##              Apollo Guidance Computer (AGC) for Apollo 12.
020237,000007:                                                                                                  ##              This file is intended to be a faithful transcription, except
020238,000008:                                                                                                  ##              that the code format has been changed to conform to the
020239,000009:                                                                                                  ##              requirements of the yaYUL assembler rather than the
020240,000010:                                                                                                  ##              original YUL assembler.
020241,000011:                                                                                                  ## Reference:   pp. 474-487
020242,000012:                                                                                                  ## Assembler:   yaYUL
020243,000013:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
020244,000014:                                                                                                  ## Website:     www.ibiblio.org/apollo/index.html
020245,000015:                                                                                                  ## Mod history: 2017-01-22 MAS  Created from Luminary 99.
020246,000016:                                                                                                  ##              2017-01-27 RSB  Back-ported a comment-text fix identified in Luminary 69.
020247,000017:                                                                                                  ##              2017-03-09 RSB  Transcribed, and then proofed comment-text using
020248,000018:                                                                                                  ##                              3-way diff vs Luminary 99 and Luminary 131.
020249,000019:                                                                                                  ##                              (Admittedly, the former is more for detecting errors
020250,000020:                                                                                                  ##                              in Luminary 99 than the other way around.)
020251,000021: 

Page 474

020253,000023:                                                                                                  #  MOD NO: 0                             DATE: 1 MAY 1968
020254,000024:                                                                                                  #  MOD BY: DIGITAL DEVEL GROUP           LOG SECTION R60,R62
020255,000025: 
020256,000026:                                                                                                  #  FUNCTIONAL DESCRIPTION:
020257,000027: 
020258,000028:                                                                                                  #  CALLED AS A GENERAL SUBROUTINE TO MANEUVER THE LM TO A SPECIFIED
020259,000029:                                                                                                  #  ATTITUDE.
020260,000030: 
020261,000031:                                                                                                  #  1. IF THE 3-AXIS FLAG IS NOT SET THE FINAL CDU ANGLES ARE
020262,000032:                                                                                                  #  CALCULATED (VECPOINT).
020263,000033: 
020264,000034:                                                                                                  #  2. THE FDAI BALL ANGLES (NOUN 18) ARE CALCULATED (BALLANGS).
020265,000035: 
020266,000036:                                                                                                  #  3. REQUEST FLASHING DISPLAY V50 N18 PLEASE PERFORM AUTO MANEUVER.
020267,000037: 
020268,000038:                                                                                                  #  4. IF PRIORITY DISPLAY FLAG IS SET DO A PHASECHANGE.  THEN AWAIT
020269,000039:                                                                                                  #  ASTRONAUT RESPONSE.
020270,000040: 
020271,000041:                                                                                                  #  5. DISPLAY RESPONSE RETURNS:
020272,000042: 
020273,000043:                                                                                                  #        A.      ENTER - RESET 3-AXIS FLAG AND RETURN TO CLIENT.
020274,000044: 
020275,000045:                                                                                                  #        B.      TERMINATE - IF IN P00 GO TO STEP 5A.  OTHERWISE CHECK IF R61 IS
020276,000046:                                                                                                  #                THE CALLING PROGRAM.  IF IN R61 AN EXIT IS MADE TO GOTOV56.  IF
020277,000047:                                                                                                  #                NOT IN R61 AN EXIT IS DONE VIA GOTOP00H.
020278,000048: 
020279,000049:                                                                                                  #        C.      PROCEED - CONTINUE WITH PROGRAM AT STEP 6.
020280,000050: 
020281,000051:                                                                                                  #  6. IF THE 3-AXISFLAG IS NOT SET, THE FINAL CDU ANGLES ARE CALCULATED
020282,000052:                                                                                                  #  (VECPOINT).
020283,000053: 
020284,000054:                                                                                                  #  7. THE FDAI BALL ANGLES (NOUN 18) ARE CALCULATED (BALLANGS).
020285,000055: 
020286,000056:                                                                                                  #  8. IF THE G+N SWITCH IS NOT SET GO BACK TO STEP 3.
020287,000057:                                                                                                  #  
020288,000058:                                                                                                  #  9. IF THE AUTO SWITCH IS NOT SET GO BACK TO STEP 3.
020289,000059: 
020290,000060:                                                                                                  #  10. NONFLASHING DISPLAY V06N18 (FDAI ANGLES).
020291,000061: 
020292,000062:                                                                                                  #  11. DO A PHASECHANGE.
020293,000063: 
020294,000064:                                                                                                  #  12. DO A MANEUVER CALCULATION AND ICDU DRIVE ROUTINE TO ACHIEVE FINAL
020295,000065: 
020296,000066:                                                                                                  #  GIMBAL ANGLES (GOMANUR).
020297,000067:                                                                                                  #  13. AT END OF MANEUVER GO TO STEP 3.
020298,000068: 
020299,000069:                                                                                                  #        IF SATISFACTORY MANEUVER STEP 5A EXITS R60.
020300,000070:                                                                                                  #        FOR FURTHER ADJUSTMENT OF THE VEHICLE ATTITUDE ABOUT THE
020301,000071:                                                                                                  #        DESIRED VECTOR, THE ROUTINE MAY BE PERFORMED AGAIN STARTING AT

Page 475

020303,000073:                                                                                                  #        STEP 5C.
020304,000074: 
020305,000075:                                                                                                  #  CALLING SEQUENCE:     TC      BANKCALL
020306,000076:                                                                                                  #                        CADR    R60LEM
020307,000077: 
020308,000078:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:     SCAXIS, POINTVSM (FOR VECPOINT)
020309,000079:                                                                                                  #                                        3AXISFLG.
020310,000080: 
020311,000081:                                                                                                  #  SUBROUTINES CALLED:   VECPOINT, BALLANGS, GOPERF2R, LINUS, GODSPER,
020312,000082:                                                                                                  #                        GOMANUR, DOWNFLAG, PHASCHNG, UPFLAG
020313,000083: 
020314,000084:                                                                                                  #  NORMAL EXIT MODES:    CAE     TEMPR60         (CALLERS RETURN ADDRESS)
020315,000085:                                                                                                  #                        TC      BANKJUMP
020316,000086: 
020317,000087:                                                                                                  #  ALARMS: NONE
020318,000088: 
020319,000089:                                                                                                  #  OUTPUT: NONE
020320,000090: 
020321,000091:                                                                                                  #  DEBRIS: CPHI, CTHETA, CPSI, 3AXISFLG, TBASE2
020322,000092: 
020323,000093: 34,2000                                           BANK     34                                    
020324,000094: 26,2000                                           SETLOC   MANUVER                               
020325,000095: 26,2000                                           BANK                                           
020326,000096: 
020327,000097: 26,2123     1163                                  EBANK=   TEMPR60                               
020328,000098: 
020329,000099: 26,2123                                           COUNT*   $$/R06                                
020330,000100: 26,2123           04645        R60LEM             TC       MAKECADR                              
020331,000101: 26,2124           55163                           TS       TEMPR60                               
020332,000102: 
020333,000103: 26,2125           05504                           TC       UPFLAG                                #  INSURE THAT TOTAL ATTITUDE ERRORS ARE
020334,000104: 26,2126           00013                           ADRES    NEEDLFLG                              #    DISPLAYED ON FDAI ERROR NEEDLES.
020335,000105: 26,2127           05516                           TC       DOWNFLAG                              
020336,000106: 26,2130           00000                           ADRES    NEED2FLG                              
020337,000107: 
020338,000108: 26,2131           34746        REDOMANN           CAF      3AXISBIT                              
020339,000109: 26,2132           70101                           MASK     FLAGWRD5                              #  IS 3-AXIS FLAG SET
020340,000110: 26,2133           10000                           CCS      A                                     
020341,000111: 26,2134           12142                           TCF      TOBALL                                #  YES
020342,000112: 26,2135           06042                           TC       INTPRET                               
020343,000113: 26,2136           77624                           CALL                                           
020344,000114: 26,2137           56040                                    VECPOINT                              #  TO COMPUTE FINAL ANGLES
020345,000115: 26,2140           00322                           STORE    CPHI                                  #  STORE FINAL ANGLES - CPHI, CTHETA, CPSI
020346,000116: 26,2141           77776                           EXIT                                           
020347,000117: 
020348,000118: 26,2142           04616        TOBALL             TC       BANKCALL                              
020349,000119: 26,2143           54272                           CADR     BALLANGS                              #  TO CONVERT ANGLES TO FDAI
020350,000120: 26,2144           32260        TOBALLA            CAF      V06N18                                

Page 476

020352,000122: 26,2145           04616                           TC       BANKCALL                              
020353,000123: 26,2146           20711                           CADR     GOPERF2R                              #  DISPLAY PLEASE PERFORM AUTO MANEUVER
020354,000124: 26,2147           02246                           TC       R61TEST                               
020355,000125: 26,2150           02154                           TC       REDOMANC                              #  PROCEED
020356,000126: 26,2151           02201                           TC       ENDMANU1                              #  ENTER I.E. FINISHED WITH R60
020357,000127: 26,2152           02205                           TC       CHKLINUS                              #  TO CHECK FOR PRIORITY DISPLAYS
020358,000128: 26,2153           05155                           TC       ENDOFJOB                              
020359,000129: 
020360,000130: 26,2154           34746        REDOMANC           CAF      3AXISBIT                              
020361,000131: 26,2155           70101                           MASK     FLAGWRD5                              #  IS 3-AXIS FLAG SET
020362,000132: 26,2156           10000                           CCS      A                                     
020363,000133: 26,2157           12165                           TCF      TOBALLC                               #  YES
020364,000134: 26,2160           06042                           TC       INTPRET                               
020365,000135: 26,2161           77624                           CALL                                           
020366,000136: 26,2162           56040                                    VECPOINT                              #  TO COMPUTE FINAL ANGLES
020367,000137: 26,2163           00322                           STORE    CPHI                                  #  STORE ANGLES
020368,000138: 26,2164           77776                           EXIT                                           
020369,000139: 
020370,000140: 26,2165           04616        TOBALLC            TC       BANKCALL                              
020371,000141: 26,2166           54272                           CADR     BALLANGS                              #  TO CONVERT ANGLES TO FDAI
020372,000142: 26,2167           02261                           TC       G+N,AUTO                              #  CHECK AUTO MODE
020373,000143: 26,2170           10000                           CCS      A                                     
020374,000144: 26,2171           12144                           TCF      TOBALLA                               #  NOT AUTO, GO REREQUEST AUTO MANEUVER.
020375,000145: 
020376,000146: 26,2172           32260        AUTOMANV           CAF      V06N18                                #  STATIC DISPLAY DURING AUTO MANEUVER
020377,000147: 26,2173           04616                           TC       BANKCALL                              #                                        -
020378,000148: 26,2174           20452                           CADR     GODSPR                                #                                        -
020379,000149: 26,2175           02205                           TC       CHKLINUS                              #  TO CHECK FOR PRIORITY DISPLAYS
020380,000150: 
020381,000151: 26,2176           04616        STARTMNV           TC       BANKCALL                              #  PERFORM MANEUVER VIA KALCMANU
020382,000152: 26,2177           17742                           CADR     GOMANUR                               
020383,000153: 
020384,000154: 26,2200           12144        ENDMANUV           TCF      TOBALLA                               #  FINISHED MANEUVER.
020385,000155: 26,2201           05516        ENDMANU1           TC       DOWNFLAG                              #  RESET 3-AXIS FLAG
020386,000156: 26,2202           00124                           ADRES    3AXISFLG                              
020387,000157: 26,2203           31163                           CAE      TEMPR60                               #                                        -
020388,000158: 26,2204           04640                           TC       BANKJUMP                              #                                        -
020389,000159: 
020390,000160: 26,2205           40100        CHKLINUS           CS       FLAGWRD4                              
020391,000161: 26,2206           74740                           MASK     PDSPFBIT                              #  IS PRIORITY DISPLAY FLAG SET?
020392,000162: 26,2207           10000                           CCS      A                                     #                                        -
020393,000163: 26,2210           00002                           TC       Q                                     #  NO - EXIT
020394,000164: 26,2211           30002                           CA       Q                                     
020395,000165: 26,2212           54156                           TS       MPAC       +2                         #  SAVE RETURN
020396,000166: 26,2213           46250                           CS       THREE                                 #  OBTAIN LOCATION FOR RESTART
020397,000167: 26,2214           60133                           AD       BUF2                                  #  HOLDS Q OF LAST DISPLAY
020398,000168: 26,2215           55054                           TS       TBASE2                                
020399,000169: 
020400,000170: 26,2216           05353                           TC       PHASCHNG                              
020401,000171: 26,2217           00132                           OCT      00132                                 

Page 477

020403,000173: 
020404,000174: 26,2220           34745                           CAF      BIT7                                  
020405,000175: 26,2221           05464                           TC       LINUS                                 #  GO SET BITS FOR PRIORITY DISPLAY      -
020406,000176: 26,2222           00156                           TC       MPAC       +2                         
020407,000177: 
020408,000178: 26,2223           37717        RELINUS            CAF      PRIO26                                #  RESTORE ORIGINAL PRIORITY
020409,000179: 26,2224           05146                           TC       PRIOCHNG                              
020410,000180: 
020411,000181: 26,2225           34747                           CAF      TRACKBIT                              #  DON'T CONTINUE R60 UNLESS TRACKFLAG ON.
020412,000182: 26,2226           70075                           MASK     FLAGWRD1                              
020413,000183: 26,2227           10000                           CCS      A                                     
020414,000184: 26,2230           12243                           TCF      RER60                                 
020415,000185: 
020416,000186: 26,2231           34745                           CAF      RNDVZBIT                              #  IS IT P20?
020417,000187: 26,2232           70074                           MASK     FLAGWRD0                              
020418,000188: 26,2233           10000                           CCS      A                                     
020419,000189: 26,2234           02240                           TC       +4                                    #  YES
020420,000190: 26,2235           05353                           TC       PHASCHNG                              #  NO, MUST BE P25, SET 2.11 SPOT
020421,000191: 26,2236           40112                           OCT      40112                                 
020422,000192: 
020423,000193: 26,2237           05155                           TC       ENDOFJOB                              
020424,000194: 
020425,000195: 26,2240           05353                           TC       PHASCHNG                              #  SET 2.7 SPOT FOR P20
020426,000196: 26,2241           40072                           OCT      40072                                 
020427,000197: 
020428,000198: 26,2242           05155                           TC       ENDOFJOB                              
020429,000199: 
020430,000200: 26,2243           05504        RER60              TC       UPFLAG                                #  SET PRIO DISPLAY FLAG AFTER RESTART
020431,000201: 26,2244           00077                           ADRES    PDSPFLAG                              
020432,000202: 
020433,000203: 26,2245           01054                           TC       TBASE2                                
020434,000204: 
020435,000205: 26,2246           31010        R61TEST            CA       MODREG                                #  IF WE ARE IN P00 IT MUST BE V49 OR V89
020436,000206: 26,2247           00006                           EXTEND                                         
020437,000207: 26,2250           12201                           BZF      ENDMANU1                              #  THUS WE GO TO ENDEXT VIA USER
020438,000208: 
020439,000209: 26,2251           30100                           CA       FLAGWRD4                              #  ARE WE IN R61 (P20 OR P25)
020440,000210: 26,2252           74740                           MASK     PDSPFBIT                              
020441,000211: 26,2253           00006                           EXTEND                                         
020442,000212: 26,2254           16001                           BZF      GOTOPOOH                              #  NO
020443,000213: 26,2255           06025                           TC       GOTOV56                               #  YES
020444,000214: 
020445,000215: 26,2256           20100        BIT14+7            OCT      20100                                 #                                        -                    
020446,000216: 26,2257           00203        OCT203             OCT      203                                   
020447,000217: 26,2260           01422        V06N18             VN       0618                                  
020448,000218:                                                                                                  #  SUBROUTINE TO CHECK FOR G+N CONTROL, AUTO STABILIZATION
020449,000219: 
020450,000220:                                                                                                  #  RETURNS WITH C(A) = +         IF NOT SET FOR G+N, AUTO
020451,000221:                                                                                                  #  RETURNS WITH C(A) = +0        IF SWITCHES ARE SET
020452,000222: 
020453,000223: 26,2261           00006        G+N,AUTO           EXTEND                                         

Page 478

020455,000225: 26,2262           00030                           READ     CHAN30                                
020456,000226: 26,2263           74742                           MASK     BIT10                                 
020457,000227: 26,2264           10000                           CCS      A                                     
020458,000228: 26,2265           00002                           TC       Q                                     #  NOT IN G+N    C(A) = +
020459,000229: 26,2266           00006        ISITAUTO           EXTEND                                         #  CHECK FOR AUTO MODE
020460,000230: 26,2267           00031                           READ     CHAN31                                
020461,000231: 26,2270           74736                           MASK     BIT14                                 
020462,000232: 26,2271           00002                           TC       Q                                     #  (+) = NOT IN AUTO, (+0) = AOK
020463,000233: 

Page 479

020465,000235:                                                                                                  #  PROGRAM DESCRIPTION BALLANGS
020466,000236:                                                                                                  #  MOD NO.                               LOG SECTION R60,R62
020467,000237: 
020468,000238:                                                                                                  #  WRITTEN BY RAMA M. AIYAWAR
020469,000239: 
020470,000240:                                                                                                  #  FUNCTIONAL DESCRIPTION
020471,000241: 
020472,000242:                                                                                                  #        COMPUTES LM FDAI BALL DISPLAY ANGLES
020473,000243: 
020474,000244:                                                                                                  #  CALLING SEQUENCE
020475,000245: 
020476,000246:                                                                                                  #        TC      BALLANGS
020477,000247: 
020478,000248:                                                                                                  #  NORMAL EXIT MODE
020479,000249: 
020480,000250:                                                                                                  #        TC      BALLEXIT        (SAVED Q)
020481,000251: 
020482,000252:                                                                                                  #  ALARM OR EXIT MODE    NIL
020483,000253: 
020484,000254:                                                                                                  #  SUBROUTINES CALLED
020485,000255: 
020486,000256:                                                                                                  #        CD*TR*G
020487,000257:                                                                                                  #        ARCTAN
020488,000258: 
020489,000259:                                                                                                  #  INPUT
020490,000260: 
020491,000261:                                                                                                  #        CPHI,CTHETA,CPSI ARE THE ANGLES CORRESPONDING TO AOG, AIG, AMG.  THEY ARE
020492,000262:                                                                                                  #        SP,2S COMPLIMENT SCALED TO HALF REVOLUTION.
020493,000263: 
020494,000264:                                                                                                  #  OUTPUT
020495,000265: 
020496,000266:                                                                                                  #        FDAIX, FDAIY, FDAIZ ARE THE REQUIRED BALL ANGLES SCALED TO HALF REVOLUTION
020497,000267:                                                                                                  #        SP,2S COMPLIMENT.
020498,000268: 
020499,000269:                                                                                                  #        THESE ANGLES WILL BE DISPLAYED AS DEGREES AND HUNDREDTHS, IN THE ORDER ROLL, PITCH, YAW, USING NOUNS 18 & 19.
020500,000270: 
020501,000271:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED
020502,000272: 
020503,000273:                                                                                                  #        CPHI, CTHETA, CPSI      EACH A SP REGISTER
020504,000274: 
020505,000275:                                                                                                  #  DEBRIS
020506,000276: 
020507,000277:                                                                                                  #        A,L,Q,MPAC,SINCDU,COSCDU,PUSHLIST,BALLEXIT
020508,000278: 
020509,000279:                                                                                                  #  NOMENCLATURE: CPHI, CTHETA, & CPSI REPRESENT THE OUTER, INNER, & MIDDLE GIMBAL ANGLES, RESPECTIVELY; OR
020510,000280:                                                                                                  #                EQUIVALENTLY, CDUX, CDUY, & CDUZ.
020511,000281: 
020512,000282:                                                                                                  #  NOTE:  ARCTAN CHECKS FOR OVERFLOW AND SHOULD BE ABLE TO HANDLE ANY SINGULARITIES.
020513,000283: 
020514,000284: 26,2000                                           SETLOC   BAWLANGS                              
020515,000285: 26,2000                                           BANK                                           
020516,000286: 
020517,000287: 26,2272                                           COUNT*   $$/BALL                               
020518,000288: 26,2272           04645        BALLANGS           TC       MAKECADR                              
020519,000289: 26,2273           55337                           TS       BALLEXIT                              
020520,000290: 26,2274           30321                           CA       CPHI                                  

Page 480

020522,000292: 26,2275           54771                           TS       CDUSPOT    +4                         
020523,000293: 26,2276           30322                           CA       CTHETA                                
020524,000294: 26,2277           54765                           TS       CDUSPOT                               
020525,000295: 26,2300           30323                           CA       CPSI                                  
020526,000296: 26,2301           54767                           TS       CDUSPOT    +2                         
020527,000297: 
020528,000298: 26,2302           06042                           TC       INTPRET                               
020529,000299: 26,2303           45001                           SETPD    CALL                                  
020530,000300: 26,2304           00001                                    0D                                    
020531,000301: 26,2305           47545                                    CD*TR*G                               
020532,000302: 
020533,000303: 26,2306           41345                           DLOAD    DMP                                   
020534,000304: 26,2307           00742                                    SINCDUX                               #  SIN (OGA)
020535,000305: 26,2310           00746                                    COSCDUZ                               #  COS (MGA)
020536,000306: 
020537,000307: 26,2311           57552                           SL1      DCOMP                                 #  SCALE
020538,000308: 26,2312           65336                           ARCSIN   PDDL                                  #  YAW = ARCSIN(-SXCZ) INTO 0 PD
020539,000309: 26,2313           00740                                    SINCDUZ                               
020540,000310: 26,2314           14023                           STODL    SINTH                                 #  (SINTH = 18D IN PD)
020541,000311: 26,2315           00746                                    COSCDUZ                               
020542,000312: 26,2316           72405                           DMP      SL1                                   #  RESCALE
020543,000313: 26,2317           00750                                    COSCDUX                               
020544,000314: 26,2320           34021                           STCALL   COSTH                                 #  (COSTH = 16D IN PD)
020545,000315: 26,2321           26510                                    ARCTAN                                
020546,000316: 26,2322           41325                           PDDL     DMP                                   #  ROLL = ARCTAN(SZ/CZCX) INTO 2 PD
020547,000317: 26,2323           00740                                    SINCDUZ                               
020548,000318: 26,2324           00742                                    SINCDUX                               
020549,000319: 26,2325           41512                           SL2      PUSH                                  #  SXSZ INTO 4 PD
020550,000320: 26,2326           65205                           DMP      PDDL                                  #  SXSZCY INTO 4 PD
020551,000321: 26,2327           00744                                    COSCDUY                               
020552,000322: 26,2330           65205                           DMP      PDDL                                  #  SXSZSY INTO 6 PD
020553,000323: 26,2331           00736                                    SINCDUY                               
020554,000324: 26,2332           00750                                    COSCDUX                               
020555,000325: 26,2333           72405                           DMP      SL1                                   #  CXCY
020556,000326: 26,2334           00744                                    COSCDUY                               
020557,000327: 26,2335           45425                           DSU      STADR                                 #  PULL UP FROM 6 PD
020558,000328: 26,2336           63756                           STODL    COSTH                                 #  COSTH = CXCY - SXSZSY
020559,000329: 26,2337           00736                                    SINCDUY                               
020560,000330: 26,2340           72405                           DMP      SL1                                   
020561,000331: 26,2341           00750                                    COSCDUX                               #  CXSY
020562,000332: 26,2342           45415                           DAD      STADR                                 #  PULL UP FROM 4 PD
020563,000333: 26,2343           43754                           STCALL   SINTH                                 #  SINTH = CXSY + SXSZCY
020564,000334: 26,2344           26510                                    ARCTAN                                #  RETURNS WITH D(MPAC) = PITCH
020565,000335: 26,2345           55525                           PDDL     VDEF                                  #  PITCH INTO 2 PD, ROLL INTO MPAC FROM 2 PD
020566,000336: 26,2346           77634                           RTB                                            #  VDEF MAKES V(MPAC) = ROLL, PITCH, YAW
020567,000337: 26,2347           21621                                    V1STO2S                               
020568,000338: 26,2350           02345                           STORE    FDAIX                                 #  MODE IS TP
020569,000339: 26,2351           77776                           EXIT                                           
020570,000340: 
020571,000341: 26,2352           31337        ENDBALL            CA       BALLEXIT                              
020572,000342: 

Page 481

020574,000344: 26,2353           04640                           TC       BANKJUMP                              
020575,000345: 

Page 482

020577,000347:                                                                                                  #  PROGRAM DESCRIPTION - VECPOINT
020578,000348: 
020579,000349:                                                                                                  #  THIS INTERPRETIVE SUBROUTINE MAY BE USED TO POINT A SPACECRAFT AXIS IN A DESIRED DIRECTION.  THE AXIS
020580,000350:                                                                                                  #  TO BE POINTED MUST APPEAR AS A HALF UNIT DOUBLE PRECISION VECTOR IN SUCCESSIVE LOCATIONS OF ERASABLE MEMORY
020581,000351:                                                                                                  #  BEGINNING WITH THE LOCATION CALLED SCAXIS.  THE COMPONENTS OF THIS VECTOR ARE GIVEN IN SPACECRAFT COORDINATES.
020582,000352:                                                                                                  #  THE DIRECTION IN WHICH THIS AXIS IS TO BE POINTED MUST APPEAR AS A HALF UNIT DOUBLE PRECISION VECTOR IN
020583,000353:                                                                                                  #  SUCCESSIVE LOCATIONS OF ERASABLE MEMORY BEGINNING WITH THE ADDRESS CALLED POINTVSM.  THE COMPONENTS OF THIS
020584,000354:                                                                                                  #  VECTOR ARE GIVEN IN STABLE MEMBER COORDINATES.  WITH THIS INFORMATION VECPOINT COMPUTES A SET OF THREE GIMBAL
020585,000355:                                                                                                  #  ANGLES (2S COMPLEMENT) CORESPONDING TO THE CROSS-PRODUCT ROTATION BETWE EN SCAXIS AND POINTVSM AND STORES THEM
020586,000356:                                                                                                  #  IN T(MPAC) BEFORE RETURNING TO THE CALLER.
020587,000357: 
020588,000358:                                                                                                  #  THIS ROTATION, HOWEVER, MAY BRING THE S/C INTO GIMBAL LOCK.  WHEN POINTING A VECTOR IN THE Y-Z PLANE,
020589,000359:                                                                                                  #  THE TRANSPONDER AXIS, OR THE AOT FOR THE LEM, THE PROGRAM WILL CORRECT THIS PROBLEM BY ROTATING THE CROSS-
020590,000360:                                                                                                  #  PRODUCT ATTITUDE ABOUT POINTVSM BY A FIXED AMOUNT SUFFICIENT TO ROTATE THE DESIRED S/C ATTITUDE OUT OF GIMBAL
020591,000361:                                                                                                  #  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,
020592,000362:                                                                                                  #  THE ADDITIONAL ROTATION TO AVOID GIMAL LOCK IS 35 DEGREES.  IF THE AXIS IS MORE THAN 60.5 DEGEES FROM +X (OR -X)
020593,000363:                                                                                                  #  THE ADDITIONAL ROTATION IS 35 DEGREES.  THE GIMBAL ANGLES CORRESPONDING TO THIS ATTITUDE ARE THEN COMPUTED AND
020594,000364:                                                                                                  #  STORED AS 2S COMPLIMENT ANGLES IN T(MPAC) BEFORE RETURNING TO THE CALLER.
020595,000365: 
020596,000366:                                                                                                  #  WHEN POINTING THE X-AXIS, OR THE THRUST VECTOR, OR ANY VECTOR WITHIN 40.6 DEG OF THE X-AXIS, VECPOINT
020597,000367:                                                                                                  #  CANNOT CORRECT FOR A CROSS-PRODUCT ROTATION INTO GIMBAL LOCK.  IN THIS CASE A PLATFORM REALIGNMENT WOULD BE
020598,000368:                                                                                                  #  REQUIRED TO POINT THE VECTOR IN THE DESIRED DIRECTION.  AT PRESENT NO INDICATION IS GIVEN FOR THIS SITUATION
020599,000369:                                                                                                  #  EXCEPT THAT THE FINAL MIDDLE GIMBAL ANGLE IN MPAC +2 IS GREATER THAN 59 DEGREES.
020600,000370: 
020601,000371:                                                                                                  #  CALLING SEQUENCE -
020602,000372: 
020603,000373:                                                                                                  #        1)      LOAD SCAXIS, POINTVSM
020604,000374:                                                                                                  #        2)      CALL
020605,000375:                                                                                                  #                        VECPOINT
020606,000376: 
020607,000377:                                                                                                  #  RETURNS WITH
020608,000378: 
020609,000379:                                                                                                  #        1)      DESIRED OUTER GIMBAL ANGLE IN MPAC
020610,000380:                                                                                                  #        2)      DESIRED INNER GIMBAL ANGLE IN MPAC +1
020611,000381:                                                                                                  #        3)      DESIRED MIDDLE GIMBAL ANGLE IN MPAC +2
020612,000382: 
020613,000383:                                                                                                  #  ERASABLES USED -
020614,000384: 
020615,000385:                                                                                                  #        1)      SCAXIS          6
020616,000386:                                                                                                  #        2)      POINTVSM        6
020617,000387:                                                                                                  #        3)      MIS             18
020618,000388:                                                                                                  #        4)      DEL             18
020619,000389:                                                                                                  #        5)      COF             6
020620,000390:                                                                                                  #        6)      VECQTEMP        1
020621,000391:                                                                                                  #        7)      ALL OF VAC AREA 43
020622,000392: 
020623,000393:                                                                                                  #                        TOTAL   99
020624,000394: 
020625,000395: 27,2000                                           SETLOC   VECPT                                 
020626,000396: 27,2000                                           BANK                                           

Page 483

020628,000398: 27,2032                                           COUNT*   $$/VECPT                              
020629,000399: 
020630,000400: 27,2032  E6,1676                                  EBANK=   BCDU                                  
020631,000401: 
020632,000402: 27,2032           40020        VECPNT1            STQ      BOV                                   #  THIS ENTRY USES DESIRED CDUS
020633,000403: 27,2033           03325                                    VECQTEMP                              #  NOT PRESENT - ENTER WITH CDUD'S IN MPAC
020634,000404: 27,2034           56035                                    VECPNT2                               
020635,000405: 27,2035           52164        VECPNT2            AXC,2    GOTO                                  
020636,000406: 27,2036           03246                                    MIS                                   
020637,000407: 27,2037           56046                                    STORANG                               
020638,000408: 27,2040           40020        VECPOINT           STQ      BOV                                   #  SAVE RETURN ADDRESS
020639,000409: 27,2041           03325                                    VECQTEMP                              
020640,000410: 27,2042           56043                                    VECLEAR                               #  AND CLEAR OVFIND
020641,000411: 27,2043           47164        VECLEAR            AXC,2    RTB                                   
020642,000412: 27,2044           03246                                    MIS                                   #  READ THE PRESENT CDU ANGLES AND
020643,000413: 27,2045           44403                                    READCDUK                              #  STORE THEM IN PD25, 26, 27
020644,000414: 27,2046           34032        STORANG            STCALL   25D                                   
020645,000415: 27,2047           44410                                    CDUTODCM                              #  S/C AXES TO STABLE MEMBER AXES (MIS)
020646,000416: 27,2050           61375                           VLOAD    VXM                                   
020647,000417: 27,2051           03773                                    POINTVSM                              #  RESOLVE THE POINTING DIRECTION VF INTO
020648,000418: 27,2052           03247                                    MIS                                   #  INITIAL S/C AXES (VF = POINTVSM)
020649,000419: 27,2053           77656                           UNIT                                           
020650,000420: 27,2054           00035                           STORE    28D                                   
020651,000421:                                                                                                  #  PD 28 29 30 31 32 33
020652,000422: 27,2055           53435                           VXV      UNIT                                  #  TAKE THE CROSS PRODUCT VF X VI
020653,000423: 27,2056           03765                                    SCAXIS                                #  WHERE VI = SCAXIS
020654,000424: 27,2057           57400                           BOV      VCOMP                                 
020655,000425: 27,2060           56170                                    PICKAXIS                              
020656,000426: 27,2061           17271                           STODL    COF                                   #  CHECK MAGNITUDE
020657,000427: 27,2062           00045                                    36D                                   #  OF CROSS PRODUCT
020658,000428: 27,2063           50025                           DSU      BMN                                   #  VECTOR, IF LESS
020659,000429: 27,2064           14415                                    DPB-14                                #  THAN B-14 ASSUME
020660,000430: 27,2065           56170                                    PICKAXIS                              #  UNIT OPERATION
020661,000431: 27,2066           50375                           VLOAD    DOT                                   #  INVALID.
020662,000432: 27,2067           03765                                    SCAXIS                                
020663,000433: 27,2070           00035                                    28D                                   
020664,000434: 27,2071           65552                           SL1      ARCCOS                                
020665,000435: 27,2072           77624        COMPMATX           CALL                                           #  NOW COMPUTE THE TRANSFORMATION FROM
020666,000436: 27,2073           44527                                    DELCOMP                               #  FINAL S/C AXES TO INITIAL S/C AXES MFI
020667,000437: 27,2074           75160                           AXC,1    AXC,2                                 
020668,000438: 27,2075           03246                                    MIS                                   #  COMPUTE THE TRANSFORMATION FROM FINAL
020669,000439: 27,2076           02230                                    KEL                                   #  S/C AXES TO STABLE MEMBER AXES
020670,000440: 27,2077           77624                           CALL                                           #  MFS = MIS MFI
020671,000441: 27,2100           44312                                    MXM3                                  #  (IN PD LIST)
020672,000442: 
020673,000443: 27,2101           51545                           DLOAD    ABS                                   
020674,000444: 27,2102           00007                                    6                                     #  MFS6 = SIN(CPSI)                      $2
020675,000445: 27,2103           50025                           DSU      BMN                                   
020676,000446: 27,2104           14402                                    SINGIMLC                              #  = SIN(59 DEGS)                        $2
020677,000447: 27,2105           56160                                    FINDGIMB                              #  /CPSI/ LESS THAN 59 DEGS

Page 484

020679,000449:                                                                                                  #  I.E. DESIRED ATTITUDE NOT IN GIMBAL LOCK
020680,000450: 
020681,000451: 27,2106           51545                           DLOAD    ABS                                   #  CHECK TO SEE IF WE ARE POINTING
020682,000452: 27,2107           03765                                    SCAXIS                                #  THE THRUST AXIS
020683,000453: 27,2110           51025                           DSU      BPL                                   
020684,000454: 27,2111           14404                                    SINVEC1                               #  SIN 49.4 DEGS                         $2
020685,000455: 27,2112           56160                                    FINDGIMB                              #  IF SO, WE ARE TRYING TO POINT IT INTO
020686,000456: 27,2113           77775                           VLOAD                                          #  GIMBAL LOCK, ABORT COULD GO HERE
020687,000457: 27,2114           77626                           STADR                                          
020688,000458: 27,2115           50514                           STOVL    MIS        +12D                       
020689,000459: 27,2116           77626                           STADR                                          #  STORE MFS (IN PD LIST) IN MIS
020690,000460: 27,2117           50522                           STOVL    MIS        +6                         
020691,000461: 27,2120           77626                           STADR                                          
020692,000462: 27,2121           50530                           STOVL    MIS                                   
020693,000463: 27,2122           03255                                    MIS        +6                         #  INNER GIMBAL AXIS IN FINAL S/C AXES
020694,000464: 27,2123           57444                           BPL      VCOMP                                 #  LOCATE THE IG AXIS DIRECTION CLOSEST TO
020695,000465: 27,2124           56125                                    IGSAMEX                               #  FINAL X S/C AXIS
020696,000466: 
020697,000467: 27,2125           50035        IGSAMEX            VXV      BMN                                   #  FIND THE SHORTEST WAY OF ROTATING THE 
020698,000468: 27,2126           03765                                    SCAXIS                                #  S/C OUT OF GIMBAL LOCK BY A ROTATION 
020699,000469: 27,2127           56134                                    U=SCAXIS                              #  ABOUT +- SCAXIS, I.E. IF  (IG (SGN MFS3)
020700,000470:                                                                                                  #  X SCAXIS . XF) LESS THAN 0, U = SCAXIS
020701,000471:                                                                                                  #  OTHERWISE U = -SCAXIS
020702,000472: 
020703,000473: 27,2130           57575                           VLOAD    VCOMP                                 
020704,000474: 27,2131           03765                                    SCAXIS                                
020705,000475: 27,2132           37271                           STCALL   COF                                   #  ROTATE ABOUT -SCAXIS
020706,000476: 27,2133           56137                                    CHEKAXIS                              
020707,000477: 27,2134           77775        U=SCAXIS           VLOAD                                          
020708,000478: 27,2135           03765                                    SCAXIS                                
020709,000479: 27,2136           03271                           STORE    COF                                   #  ROTATE ABOUT + SCAXIS
020710,000480: 27,2137           51545        CHEKAXIS           DLOAD    ABS                                   
020711,000481: 27,2140           03765                                    SCAXIS                                #  SEE IF WE ARE POINTING THE AOT
020712,000482: 27,2141           51025                           DSU      BPL                                   
020713,000483: 27,2142           14406                                    SINVEC2                               #  SIN 29.5 DEGS                         $2
020714,000484: 27,2143           56147                                    PICKANG1                              #  IF SO, ROTATE 50 DEGS ABOUT +- SCAXIS
020715,000485: 27,2144           52145                           DLOAD    GOTO                                  #  IF NOT, MUST BE POINTING THE TRANSPONDER
020716,000486: 27,2145           14412                                    VECANG2                               #  OR SOME VECTOR IN THE Y, OR Z PLANE
020717,000487: 27,2146           56151                                    COMPMFSN                              #  IN THIS CASE ROTATE 35 DEGS TO GET OUT
020718,000488:                                                                                                  #  OF GIMBAL LOCK (VECANG2  $360)
020719,000489: 27,2147           77745        PICKANG1           DLOAD                                          
020720,000490: 27,2150           14410                                    VECANG1                               #  = 50 DEGS                             $360
020721,000491: 27,2151           77624        COMPMFSN           CALL                                           
020722,000492: 27,2152           44527                                    DELCOMP                               #  COMPUTE THE ROTATION ABOUT SCAXIS TO
020723,000493: 27,2153           75160                           AXC,1    AXC,2                                 #  BRING MFS OUT OF GIMBAL LOCK
020724,000494: 27,2154           03246                                    MIS                                   
020725,000495: 27,2155           02230                                    KEL                                   
020726,000496: 27,2156           77624                           CALL                                           #  COMPUTE THE NEW TRANSFORMATION FROM
020727,000497: 27,2157           44312                                    MXM3                                  #  DESIRED S/C AXES TO STABLE MEMBER AXES
020728,000498:                                                                                                  #  WHICH WILL ALIGN VI WITH VF AND AVOID

Page 485

020730,000500:                                                                                                  #  GIMBAL LOCK
020731,000501: 27,2160           45160        FINDGIMB           AXC,1    CALL                                  
020732,000502: 27,2161           00000                                    0                                     #  EXTRACT THE COMMANDED CDU ANGLES FROM
020733,000503: 27,2162           44654                                    DCMTOCDU                              #  THIS MATRIX
020734,000504: 27,2163           40234                           RTB      SETPD                                 
020735,000505: 27,2164           21621                                    V1STO2S                               #  CONVERT TO 2:S COMPLEMENT
020736,000506: 27,2165           00001                                    0                                     
020737,000507: 27,2166           77650                           GOTO                                           
020738,000508: 27,2167           03325                                    VECQTEMP                              #  RETURN TO CALLER
020739,000509: 
020740,000510: 27,2170           50375        PICKAXIS           VLOAD    DOT                                   #  IF VF X VI = 0, FIND VF . VI
020741,000511: 27,2171           00035                                    28D                                   
020742,000512: 27,2172           03765                                    SCAXIS                                
020743,000513: 27,2173           72240                           BMN      TLOAD                                 
020744,000514: 27,2174           54354                                    ROT180                                
020745,000515: 27,2175           00032                                    25D                                   
020746,000516: 27,2176           77650                           GOTO                                           #  IF VF = VI, CDU DESIRED = PRESENT CDU
020747,000517: 27,2177           03325                                    VECQTEMP                              #  PRESENT CDU ANGLES
020748,000518: 
020749,000519: 35,2000                                           BANK     35                                    
020750,000520: 26,2000                                           SETLOC   MANUVER1                              
020751,000521: 26,2000                                           BANK                                           
020752,000522: 26,2354           47375        ROT180             VLOAD    VXV                                   #  IF VF, VI ANTIPARALLEL, 108 DEG ROTATION
020753,000523: 26,2355           03255                                    MIS        +6                         #  IS REQUIRED.  Y STABLE MEMBER AXIS IN
020754,000524: 26,2356           06522                                    HIDPHALF                              #  INITIAL S/C AXES.
020755,000525: 26,2357           47256                           UNIT     VXV                                   #  FIND Y(SM) X X(I)
020756,000526: 26,2360           03765                                    SCAXIS                                #  FIND UNIT(VI X UNIT(Y(SM) X X(I)))
020757,000527: 26,2361           40056                           UNIT     BOV                                   #  I.E. PICK A VECTOR IN THE PLANE OF X(I),
020758,000528: 26,2362           54376                                    PICKX                                 #  Y(SM) PERPENDICULAR TO VI
020759,000529: 26,2363           17271                           STODL    COF                                   
020760,000530: 26,2364           00045                                    36D                                   #  CHECK MAGNITUDE
020761,000531: 26,2365           50025                           DSU      BMN                                   #  OF THIS VECTOR.
020762,000532: 26,2366           14415                                    DPB-14                                #  IF LESS THAN B-14,
020763,000533: 26,2367           54376                                    PICKX                                 #  PICK X-AXIS.
020764,000534: 26,2370           77775                           VLOAD                                          
020765,000535: 26,2371           03271                                    COF                                   
020766,000536: 26,2372           17271        XROT               STODL    COF                                   
020767,000537: 26,2373           06522                                    HIDPHALF                              
020768,000538: 26,2374           77650                           GOTO                                           
020769,000539: 26,2375           56072                                    COMPMATX                              
020770,000540: 26,2376           52175        PICKX              VLOAD    GOTO                                  #  PICK THE XAXIS IN THIS CASE
020771,000541: 26,2377           06522                                    HIDPHALF                              
020772,000542: 26,2400           54372                                    XROT                                  
020773,000543: 26,2401           15555 35172  SINGIMLC           2DEC     .4285836003                            #  = SIN(59)                             $2
020774,000544: 
020775,000545: 26,2403           14113 36326  SINVEC1            2DEC     .3796356537                            #  = SIN(49.4)                           $2
020776,000546: 
020777,000547: 26,2405           07701 35703  SINVEC2            2DEC     .2462117800                            #  = SIN(29.5)                           $2
020778,000548: 
020779,000549: 26,2407           04343 21616  VECANG1            2DEC     .1388888889                            #  = 50 DEGREES                          $360

Page 486

020781,000551: 26,2411           03070 34344  VECANG2            2DEC     .09722222222                            #  = 35 DEGREES                          $360
020782,000552: 
020783,000553: 26,2413           00000        1BITDP             OCT      0                                     #  KEEP THIS BEFORE DPB(-14)        *********
020784,000554: 26,2414           00001        DPB-14             OCT      00001                                 
020785,000555: 26,2415           00000                           OCT      00000                                 
020786,000556: 

Page 487

020788,000558:                                                                                                  #  ROUTINE FOR INITIATING AUTOMATIC MANEUVER VIA KEYBOARD (V49)
020789,000559: 
020790,000560: 34,2000                                           BANK     34                                    
020791,000561: 23,2000                                           SETLOC   R62                                   
020792,000562: 23,2000                                           BANK                                           
020793,000563: 23,2103  E6,1676                                  EBANK=   BCDU                                  
020794,000564: 
020795,000565: 23,2103                                           COUNT*   $$/R62                                
020796,000566: 
020797,000567: 23,2103  23,2103               R62DISP            EQUALS   R62FLASH                              
020798,000568: 
020799,000569: 23,2103           35010        R62FLASH           CAF      V06N22                                #  FLASH V06N22 AND
020800,000570: 23,2104           04616                           TC       BANKCALL                              #  ICDU ANGLES
020801,000571: 23,2105           20477                           CADR     GOFLASH                               
020802,000572: 23,2106           15472                           TCF      ENDEXT                                #  TERMINATE
020803,000573: 23,2107           12111                           TCF      GOMOVE                                #  PROCEED
020804,000574: 23,2110           12103                           TCF      R62FLASH                              #  ENTER
020805,000575: 
020806,000576:                                                                                                  #  ASTRONAUT MAY LOAD NEW ICDUS AT THIS
020807,000577:                                                                                                  #  POINT
020808,000578: 23,2111           05504        GOMOVE             TC       UPFLAG                                #  SET FOR 3-AXIS MANEUVER
020809,000579: 23,2112           00124                           ADRES    3AXISFLG                              
020810,000580: 
020811,000581: 23,2113           04616                           TC       BANKCALL                              
020812,000582: 23,2114           54123                           CADR     R60LEM                                
020813,000583: 23,2115           15472                           TCF      ENDEXT                                #  END R62
020814,000584: 

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