https://github.com/virtualagc/virtualagc
Revision 078c79d8734a9ed2860303a7c1662004284fe853 authored by Ron Burkey on 07 August 2022, 15:04:04 UTC, committed by Ron Burkey on 07 August 2022, 15:04:04 UTC
assembly listings from yaASM and yaLEMAP. Added some debugging messages
to 'make install'.  Tweaked debugging messages that VirtualAGC embeds in
'simulate'.  Verified buildability in Mint 21, 20, 19, 17, and verified
buildability using clang in Mint 17.
1 parent 6bb1acc
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Tip revision: 078c79d8734a9ed2860303a7c1662004284fe853 authored by Ron Burkey on 07 August 2022, 15:04:04 UTC
Fixed a potential string-overflow bug in yaASM. Removed timestamps from
Tip revision: 078c79d
ATTITUDE_MANEUVER_ROUTINE.agc
### FILE="Main.annotation"
## Copyright:   Public domain.
## Filename:    ATTITUDE_MANEUVER_ROUTINE.agc
## Purpose:     A section of Luminary revision 173.
##              It is part of the reconstructed source code for the second
##              (unflown) release of the flight software for the Lunar
##              Module's (LM) Apollo Guidance Computer (AGC) for Apollo 14.
##              The code has been recreated from a reconstructed copy of
##              Luminary 178, as well as Luminary memo 167 (revision 1).
##              It has been adapted such that the resulting bugger words
##              exactly match those specified for Luminary 173 in NASA
##              drawing 2021152N, which gives relatively high confidence
##              that the reconstruction is correct.
## Reference:   pp. 347-368
## Assembler:   yaYUL
## Contact:     Ron Burkey <info@sandroid.org>.
## Website:     www.ibiblio.org/apollo/index.html
## Mod history: 2019-09-18 MAS  Created from Luminary 178.

## Page 347
# BLOCK 2 LGC ATTITUDE MANEUVER ROUTINE-KALCMANU


# MOD 2           DATE 5/1/67     BY DON KEENE

# PROGRAM DESCRIPTION

#      KALCMANU IS A ROUTINE WHICH GENERATES COMMANDS FOR THE LM DAP TO CHANGE THE ATTITUDE OF THE SPACECRAFT
# DURING FREE FALL.  IT IS DESIGNED TO MANEUVER THE SPACECRAFT FROM ITS INITIAL ORIENTATION TO SOME DESIRED
# ORIENTATION SPECIFIED BY THE PROGRAM WHICH CALLS KALCMANU, AVOIDING GIMBAL LOCK IN THE PROCESS.  IN THE
# MOD 2 VERSION, THIS DESIRED ATTITUDE IS SPECIFIED BY A SET OF THREE COMMANDED CDU ANGLES STORED AS 2S COMPLEMENT
# SINGLE PRECISION ANGLES IN THE THREE CONSECUTIVE LOCATIONS, CPHI, CTHETA, CPSI, WHERE

#      CPHI = COMMANDED OUTER GIMBAL ANGLE
#      CTHETA = COMMANDED INNER GIMBAL ANGLE
#      CPSI = COMMANDED MIDDLE GIMBAL ANGLE

#     WHEN POINTING A SPACECRAFT AXIS (E.I. X, Y, Z, THE AOT, THRUST AXIS, ETC) THE SUBROUTINE VECPOINT MAY BE
# USED TO GENERATE THIS SET OF DESIRED CDU ANGLES (SEE DESCRIPTION IN R60)   -
#  WITH THIS INFORMATION KALCMANU DETERMINES THE DIRECTION OF THE SINGLE EQUIVALENT ROTATION (COF ALSO U) AND THE
# MAGNITUDE OF THE ROTATION (AM) TO BRING THE S/C FROM ITS INITIAL ORIENTATION TO ITS FINAL ORIENTATION.
# THIS DIRECTION REMAINS FIXED BOTH IN INERTIAL COORDINATES AND IN COMMANDED S/C AXES THROUGHOUT THE
#                  -
# MANEUVER.  ONCE COF AND AM HAVE BEEN DETERMINED, KALCMANU THEN EXAMINES THE MANEUVER TO SEE IF IT WILL BRING
#                                       -
# THE S/C THROUGH GIMBAL LOCK.  IF SO, COF AND AM ARE READJUSTED SO THAT THE S/C WILL JUST SKIM THE GIMBAL
# LOCK ZONE AND ALIGN THE X-AXIS.  IN GENERAL A FINAL YAW  ABOUT X WILL BE NECESSARY TO COMPLETE THE MANEUVER.
# NEEDLESS TO SAY, NEITHER THE INITIAL NOR THE FINAL ORIENTATION CAN BE IN GIMBAL LOCK.
#
#      FOR PROPER ATTITUDE CONTROL THE DIGITAL AUTOPILOT MUST BE GIVEN AN ATTITUDE REFERENCE WHICH IT CAN TRACK.
# KALCMANU DOES THIS BY GENERATING A REFERENCE OF DESIRED GIMBAL ANGLES (CDUXD, CDUYD, CDUZD) WHICH ARE UPDATED
# EVERY ONE SECOND DURING THE MANEUVER.  TO ACHIEVE A SMOOTHER SEQUENCE OF COMMANDS BETWEEN SUCCESSIVE UPDATES,
# THE PROGRAM ALSO GENERATES A SET OF INCREMENTAL CDU ANGLES (DELDCDU) TO BE ADDED TO CDU DESIRED BY THE DIGITAL
# AUTOPILOT.  KALCMANU ALSO CALCULATES THE COMPONENT MANEUVER RATES (OMEGAPD, OMEGAQD, OMEGARD), WHICH CAN
#                                      -
# BE DETERMINED SIMPLY BY MULTIPLYING COF BY SOME SCALAR (ARATE) CORRESPONDING TO THE DESIRED ROTATIONAL RATE.
#
#      AUTOMATIC MANEUVERS ARE TIMED WITH THE HELP OF WAITLIST SO THAT AFTER A SPECIFIED INTERVAL THE Y AND Z
# DESIRED RATES ARE SET TO ZERO AND THE DESIRED CDU ANGLES (CDUYD, CDUZD) ARE SET EQUAL TO THE FINAL DESIRED CDU
# ANGLES (CTHETA, CPSI).  IF ANY YAW  REMAINS DUE TO GIMBAL LOCK AVOIDANCE, THE FINAL YAW  MANEUVER IS
# CALCULATED AND THE DESIRED YAW  RATE SET TO SOME FIXED VALUE (ROLLRATE = + OR - 2 DEGREES PER SEC).
# IN THIS CASE ONLY AN INCREMENTAL CDUX ANGLE (DELFROLL) IS SUPPLIED TO THE DAP.  AT THE END OF THE YAW
# MANEUVER OR IN THE EVENT THAT THERE WAS NO FINAL YAW,  CDUXD IS SET EQUAL TO CPHI AND THE X-AXIS DESIRED
# RATE SET TO ZERO.  THUS, UPON COMPLETION OF THE MANEUVER THE S/C WILL FINISH UP IN A LIMIT CYCLE ABOUT THE
# DESIRED FINAL GIMBAL ANGLES.


# PROGRAM LOGIC FLOW

#      KALCMANU IS CALLED AS A HIGH PRIORITY JOB WITH ENTRY POINTS AT KALCMAN3 AND VECPOINT.  IT FIRST PICKS
# UP THE CURRENT CDU ANGLES TO BE USED AS THE BASIS FOR ALL COMPUTATIONS INVOLVING THE INITIAL S/C ORIENTATION.

## Page 348
# IT THEN DETERMINES THE DIRECTION COSINE MATRICES RELATING BOTH THE INITIAL AND FINAL S/C ORIENTATION TO STABLE
#               *    *                                                                               *
# MEMBER AXES (MIS, MFS).  IT ALSO COMPUTES THE MATRIX RELATING FINAL S/C AXES TO INITIAL S/C AXES (MFI).  THE
# ANGLE OF ROTATION (AM) IS THEN EXTRACTED FROM THIS MATRIX, AND TESTS ARE MADE TO DETERMINE IF
#
#      A)  AM LESS THAN .25 DEGREES (MINANG)
#      B)  AM GREATER THAN 170 DEGREES (MAXANG)

#      IF AM LESS THAN .25 DEGREES, NO COMPLICATED AUTOMATIC MANEUVERING IS NECESSARY.  THEREFORE WE CAN SIMPLY
# SET CDU DESIRED EQUAL TO THE FINAL CDU DESIRED ANGLES AND TERMINATE THE JOB.
#
#      IF AM IS GREATER THAN .25 DEGREES BUT LESS THAN 170 DEGREES, THE AXES OF THE SINGLE EQUIVALENT ROTATION
#   -                                                       *
# (COF) IS EXTRACTED FROM THE SKEW SYMMETRIC COMPONENTS OF MFI.                            *     *
#      IF AM GREATER THAN 170 DEGREES AN ALTERNATE METHOD EMPLOYING THE SYMMETRIC PART OF MFI (MFISYM) IS USED
#               -
# TO DETERMINE COF.

#      THE PROGRAM THEN CHECKS TO SEE IF THE MANEUVER AS COMPUTED WILL BRING THE S/C THROUGH GIMBAL LOCK.  IF
# SO, A NEW MANEUVER IS CALCULATED WHICH WILL JUST SKIM THE GIMBAL LOCK ZONE AND ALIGN THE S/C X-AXIS.  THIS
# METHOD ASSURES THAT THE ADDITIONAL MANEUVERING TO AVOID GIMBAL LOCK WILL BE KEPT TO A MINIMUM.  SINCE A FINAL
# P AXIS YAW WILL BE NECESSARY, A SWITCH IS RESET (STATE SWITCH 31) TO ALLOW FOR THE COMPUTATION OF THIS FINAL
# YAW.

#      AS STATED PREVIOUSLY KALCMANU GENERATES A SEQUENCE OF DESIRED GIMBAL ANGLES WHICH ARE UPDATED EVERY
#                                                                                              -
# SECOND.  THIS IS ACCOMPLISHED BY A SMALL ROTATION OF THE DESIRED S/C FRAME ABOUT THE VECTOR COF.  THE NEW
# DESIRED REFERENCE MATRIX IS THEN,

#                  *              *         *
#                 MIS       =    MIS       DEL
#                    N+1             N
#        *
# WHERE DEL IS THE MATRIX CORRESPONDING TO THIS SMALL ROTATION.  THE NEW CDU ANGLES CAN THEN BE EXTRACTED
#       *
# FROM MIS.

#      AT THE BEGINNING OF THE MANEUVER THE AUTOPILOT DESIRED RATES (OMEGAPD, OMEGAQD, OMEGARD) AND THE
# MANEUVER TIMINGS ARE ESTABLISHED.  ON THE FIRST PASS AND ON ALL SUBSEQUENT UPDATES THE CDU DESIRED
# ANGLES ARE LOADED WITH THE APPROPRIATE VALUES AND THE INCREMENTAL CDU ANGLES ARE COMPUTED.  THE AGC CLOCKS
# (TIME1 AND TIME2) ARE THAN CHECKED TO SEE IF THE MANEUVER WILL TERMINATE BEFORE THE NEXT UPDATE.  IF
# NOT, KALCMANU CALLS FOR ANOTHER UPDATE (RUN AS A JOB WITH PRIORITY TBD) IN ONE SECOND.  ANY DELAYS IN THIS
# CALLING SEQUENCE ARE AUTOMATICALLY COMPENSATED IN CALLING FOR THE NEXT UPDATE.
#
#      IF IT IS FOUND THAT THE MANEUVER IS TO TERMINATE BEFORE THE NEXT UPDATE A ROUTINE IS CALLED (AS A WAIT-
# LIST TASK) TO STOP THE MANEUVER AT THE APPROPRIATE TIME AS EXPLAINED ABOVE.

## Page 349
# CALLING SEQUENCE

#      IN ORDER TO PERFORM A KALCMANU SUPERVISED MANEUVER, THE COMMANDED GIMBAL ANGLES MUST BE PRECOMPUTED AND
# STORED IN LOCATIONS CPHI, CTHETA, CPSI.  THE USER:S PROGRAM MUST THEN CLEAR STATE SWITCH NO 33 TO ALLOW THE
# ATTITUDE MANEUVER ROUTINE TO PERFORM ANY FINAL P-AXIS YAW INCURRED BY AVOIDING GIMBAL LOCK.  THE MANEUVER IS
# THEN INITIATED BY ESTABLISHING THE FOLLOWING EXECUTIVE JOB

#                        *
#      CAF     PRIO    XX
#                      --
#      INHINT
#      TC         FINDVAC
#      2CADR      KALCMAN3
#      RELINT

# THE USER:S PROGRAM MAY EITHER CONTINUE OR WAIT FOR THE TERMINATION OF THE MANEUVER.  IF THE USER WISHES TO
# WAIT, HE MAY PUT HIS JOB TO SLEEP WITH THE FOLLOWING INSTRUCTIONS

#      L          TC        BANKCALL
#      L+1        CADR      ATTSTALL
#      L+2        (BAD      RETURN)
#      L+3        (GOOD     RETURN)

#      UPON COMPLETION OF THE MANEUVER, THE PROGRAM WILL BE AWAKENED AT L+3 IF THE MANEUVER WAS COMPLETED
# SUCCESSFULLY, OR AT L+2 IF THE MANEUVER WAS ABORTED.  THIS ABORT WOULD OCCUR IF THE INITIAL OR FINAL ATTITUDE
# WAS IN GIMBAL LOCK.

# ***NOTA BENE***  IT IS ASSUMED THAT THE DESIRED MANEUVERING RATE (0.5, 2, 5, 10, DEG/SEC) HAS BEEN SELECTED BY
# KEYBOARD ENTRY PRIOR TO THE EXECUTION OF KALCMANU.
#     IT IS ALSO ASSUMED THAT THE AUTOPILOT IS IN THE AUTO MODE.  IF THE MODE SWITCH IS CHANGED DURING THE
# MANEUVER, KALCMANU WILL TERMINATE VIA GOODEND WITHIN 1 SECOND SO THAT R60 MAY REQUEST A TRIM OF THE S/C ATTITUDE
# THIS IS THE ONLY MEANS FOR MANUALLY TERMINATING A KALCMANU SUPERVISED MANEUVER.
# SUBROUTINES

#      KALCMANU USES A NUMBER OF INTERPRETIVE SUBROUTINES WHICH MAY BE OF GENERAL INTEREST.  SINCE THESE ROUTINES
# WERE PROGRAMMED EXCLUSIVELY FOR KALCMANU, THEY ARE NOT, AS YET, GENERALLY AVAILABLE FOR USE BY OTHER PROGRAMS.
#
#      MXM3
#      ----

#      THIS SUBROUTINE MULTIPLIES TWO 3X3 MATRICES AND LEAVES THE RESULT IN THE FIRST 18 LOCATIONS OF THE PUSH
# DOWN LIST, I.E.,

#                (M    M    M )
#                (  0   1    2)
#       *        (            )       *         *
#       M    =   (M    M    M )  =    M1   X    M2
#                ( 3    4    5)
#                (            )
#                (M    M    M )

## Page 350
#                ( 6    7    8)

#                                                                                       *
#      INDEX REGISTER X1 MUST BE LOADED WITH THE COMPLEMENT OF THE STARTING ADDRESS FOR M1, AND X2 MUST BE
#                                                        *
# LOADED WITH THE COMPLEMENT OF THE STARTING ADDRESS FOR M2.   THE ROUTINE USES THE FIRST 20 LOCATIONS OF THE PUSH
# DOWN LIST.  THE FIRST ELEMENT OF THE MATRIX APPEARS IN PDO.  PUSH UP FOR M .
#                                                                           8
#
#      TRANSPOS
#      --------

#      THIS ROUTINE TRANSPOSES A 3X3 MATRIX AND LEAVES THE RESULT IN THE PUSH DOWN LIST, I.E.,
#
#       *         * T
#       M    =    M1

# INDEX REGISTER X1 MUST CONTAIN THE COMPLEMENT OF THE STARTING ADDRESS FOR M1.  PUSH UP FOR THE FIRST AND SUB-
#                       *
# SEQUENT COMPONENTS OF M.   THIS SUBROUTINE ALSO USES THE FIRST 20 LOCATIONS OF THE PUSH DOWN LIST.
#
#      CDU TO DCM
#      ----------

#      THIS SUBROUTINE CONVERTS THREE CDU ANGLES IN T(MPAC) TO A DIRECTION COSINE MATRIX (SCALED BY 2) RELATING
# THE CORRESPONDING S/C ORIENTATIONS TO THE STABLE MEMBER FRAME.  THE FORMULAS FOR THIS CONVERSION ARE
#
#       M    =    COSY  COSZ
#        0

#       M    =    -COSY  SINZ  COSX  +  SINY  SINX
#        1

#       M    =    COSY  SINZ  SINX  +  SINY  COSX
#        2

#       M    =    SINZ
#        3

#       M    =    COSZ  COSX
#        4

#       M    =    -COSZ  SINX
#        5

#       M    =    -SINY  COSZ
#        6
#
#       M    =    SINY  SINZ  COSX  +  COSY  SINX
#        7

## Page 351
#       M    =    -SINY  SINZ  SINX  +  COSY  COSX
#        8

# WHERE      X    =    OUTER GIMBAL ANGLE
#            Y    =    INNER GIMBAL ANGLE
#            Z    =    MIDDLE GIMBAL ANGLE

#      THE INTERPRETATION OF THIS MATRIX IS AS FOLLOWS

#      IF A , A , A  REPRESENT THE COMPONENTS OF A VECTOR IN S/C AXES THEN THE COMPONENTS OF THE SAME VECTOR IN
#          X   Y   Z
# STABLE MEMBER AXES (B , B , B ) ARE
#                      X   Y   Z

#            (B )                (A )
#            ( X)                ( X)
#            (  )                (  )
#            (  )           *    (  )
#            (B )      =    M    (A )
#            ( Y)                ( Y)
#            (  )                (  )
#            (B )                (A )
#            ( Z)                ( Z)

#     THE SUBROUTINE WILL STORE THIS MATRIX IN SEQUENTIAL LOCATIONS OF ERASABLE MEMORY AS SPECIFIED BY THE CALLING
#                                                                                                             *
# PROGRAM.  TO DO THIS THE CALLING PROGRAM MUST FIRST LOAD X2 WITH THE COMPLEMENT OF THE STARTING ADDRESS FOR M.
#
#      INTERNALLY, THE ROUTINE USES THE FIRST 16 LOCATIONS OF THE PUSH DOWN LIST, ALSO STEP REGISTER S1 AND INDEX
# REGISTER X2.


#      DCM TO CDU
#      ----------
#                                                                           *
#      THIS ROUTINE EXTRACTS THE CDU ANGLES FROM A DIRECTION COSINE MATRIX (M SCALED BY 2) RELATING S/C AXIS TO
#                                                                                 *
# STABLE MEMBER AXES.  X1 MUST CONTAIN THE COMPLEMENT OF THE STARTING ADDRESS FOR M.  THE SUBROUTINE LEAVES THE
# CORRESPONDING GIMBAL ANGLES IN V(MPAC) AS DOUBLE PRECISION 1:S COMPLEMENT ANGLES SCALED BY 2PI.  THE FORMULAS
# FOR THIS CONVERSION ARE

#       Z    =    ARCSIN (M  )
#                          3

#       Y    =    ARCSIN (-M /COSZ)
#                           6

# IF M  IS NEGATIVE, Y IS REPLACED BY PI SGN Y - Y
#     0

## Page 352
#       X    =    ARCSIN (-M /COSZ)
#                           5

# IF M  IS NEGATIVE X IS REPLACED BY PI SGN X - X
#     4

#      THIS ROUTINE DOES NOT SET THE PUSH DOWN POINTER, BUT USES THE NEXT 8 LOCATIONS OF THE PUSH DOWN LIST AND
# RETURNS THE POINTER TO ITS ORIGINAL SETTING.  THIS PROCEDURE ALLOWS THE CALLER TO STORE THE MATRIX AT THE TOP OF
# THE PUSH DOWN LIST.


#      DELCOMP
#      -------

#                                                          *
#      THIS ROUTINE COMPUTES THE DIRECTION COSINE MATRIX (DEL) RELATING ON
#                                                                          -
# IS ROTATED WITH RESPECT TO THE FIRST BY AN ANGLE, A, ABOUT A UNIT VECTOR, U.  THE FORMULA FOR THIS MATRIX IS
#
#       *         *           --T           *
#       DEL  =    I  COSA  +  UU (1-COSA) + V SINA
#                                            X

# WHERE      *         (1    0    0)
#            I    =    (0    1    0)
#                      (0    0    1)


#                         2
#                      (U         U U       U  U )
#                      ( X         X Y       X  Z)
#                      (                         )
#            --T       (            2            )
#            UU   =    (U U       U         U U  )
#                      ( Y X       Y         Y Z )
#                      (                         )
#                      (                      2  )
#                      (U U       U U       U   )
#                      ( Z X       Z Y       Z   )


#                      (0         -U        U  )
#                      (            Z        Y )
#            *         (                       )
#            V    =    (U         0         -U )
#             X        ( Z                    X)
#                      (                       )
#                      (-U        U         0  )
#                      (  Y        X           )

## Page 353
#            -
#            U    =    UNIT ROTATION VECTOR RESOLVED INTO S/C AXES
#            A    =    ROTATION ANGLE

#                             *
#      THE INTERPRETATION OF DEL IS AS FOLLOWS

#      IF A , A , A  REPRESENT THE COMPONENT OF A VECTOR INTHE ROTATED FRAME, THEN THE COMPONENTS OF THE SAME
#          X   Y   Z
# VECTOR IN THE ORIGINAL S/C AXES (B , B , B ) ARE
#                                   X   Y   Z

#             (B )                    (A )
#             ( X)                    ( X)
#             (  )           *        (  )
#             (B )     =    DEL       (A )
#             ( Y)                    ( Y)
#             (  )                    (  )
#             (B )                    (A )
#             ( Z)                    ( Z)

#      THE ROUTINE WILL STORE THIS MATRIX (SCALED UNITY) IN SEQUENTIAL LOCATIONS OF ERASABLE MEMORY BEGINNING WITH
#                                                                                             -
# THE LOCATION CALLED DEL.  IN ORDER TO USE THE ROUTINE, THE CALLING PROGRAM MUST FIRST STORE U (A HALF UNIT
# DOUBLE PRECISION VECTOR) IN THE SET OF ERASABLE LOCATIONS BEGINNING WITH THE ADDRESS CALLED COF.  THE ANGLE, A,
# MUST THEN BE LOADED INTO D(MPAC).

#      INTERNALLY, THE PROGRAM ALSO USES THE FIRST 10 LOCATIONS OF THE PUSH DOWN LIST.
#

#      READCDUK
#      --------

#      THIS BASIC LANGUAGE SUBROUTINE LOADS T(MPAC) WITH THE THREE CDU ANGLES.


#     SIGNMPAC
#      --------

#      THIS IS A BASIC LANGUAGE SUBROUTINE WHICH LIMITS THE MAGNITUDE OF D(MPAC) TO + OR - DPOSMAX ON OVERFLOW.
#

#      PROGRAM STORAGE ALLOCATION

#            1)   FIXED MEMORY                       1059 WORDS
#            2)   ERASABLE MEMORY                      98
#            3)   STATE SWITCHES                        3

## Page 354
#            4)   FLAGS                                 1

#      JOB PRIORITIES

#            1)   KALCMANU                            TBD
#            2)   ONE SECOND UPDATE                   TBD


#      SUMMARY OF STATE SWITCHES AND FLAGWORDS USED BY KALCMANU.


# STATE                FLAGWRD 2      SETTING             MEANING
# SWITCH NO.            BIT NO.

#   *
# 31                      14            0       MANEUVER WENT THROUGH GIMBAL LOCK
#                                       1       MANEUVER DID NOT GO THROUGH GIMBAL LOCK
#
#   *
# 32                      13            0       CONTINUE UPDATE PROCESS
#                                       1       START UPDATE PROCESS

# 33                      12            0       PERFORM FINAL P-AXIS YAW IF REQUIRED
#                                       1       IGNORE ANY FINAL P-AXIS YAW
#
# 34                      11            0       SIGNAL END OF KALCMANU
#                                       1       KALCMANU IN PROCESS       USER MUST SET SWITCH BEFORE INITIATING


#         * INTERNAL TO KALCMANU


#      SUGGESTIONS FOR PROGRAM INTEGRATION

#      THE FOLLOWING VARIABLES SHOULD BE ASSIGNED TO UNSWITCH ERASABLE

#                      CPHI
#                      CTHETA
#                      CPSI
#                      POINTVSM  +5
#                      SCAXIS    +5
#                      DELDCDU
#                      DELDCDU1
#                      DELDCDU2
#                      RATEINDX

#      THE FOLLOWING SUBROUTINES MAY BE PUT IN A DIFFERENT BANK

#                      MXM3
## Page 355
#                      TRANSPOS
#                      SIGNMPAC
#                      READCDUK
#                      CDUTODCM

## Page 356
                BANK            15
                SETLOC          KALCMON1
                BANK

                EBANK=          BCDU

# THE THREE DESIRED CDU ANGLES MUST BE STORED AS SINGLE PRECISION TWOS COMPLEMENT ANGLES IN THE THREE SUCCESSIVE
# LOCATIONS, CPHI, CTHETA, CPSI.

                COUNT*          $$/KALC
KALCMAN3        TC              INTPRET                 # PICK UP THE CURRENT CDU ANGLES AND
                RTB                                     #   COMPUTE THE MATRIX FROM INITIAL S/C
                                READCDUK                #   AXES TO FINAL S/C AXES
                STORE           BCDU                    # STORE INITIAL S/C ANGLES
                SLOAD           ABS                     # CHECK THE MAGNITUDE OF THE DESIRED
                                CPSI                    # MIDDLE GIMBAL ANGLE
                DSU             BPL
                                LOCKANGL                # IF GREATER THAN 70 DEG ABORT MANEUVER
                                TOOBADF
                AXC,2           TLOAD
                                MIS
                                BCDU
                CALL                                    # COMPUTE THE TRANSFORMATION FROM INITIAL
                                CDUTODCM                # S/C AXES TO STABLE MEMBER AXES
                AXC,2           TLOAD
                                MFS                     # PREPARE TO CALCULATE ARRAY MFS
                                CPHI
                CALL
                                CDUTODCM
SECAD           AXC,1           CALL                    # MIS AND MFS ARRAYS CALCULATED         $2
                                MIS
                                TRANSPOS
                VLOAD           STADR
                STOVL           TMIS            +12D
                STADR
                STOVL           TMIS            +6
                STADR
                STORE           TMIS                    # TMIS = TRANSPOSE(MIS) SCALED BY 2
                AXC,1           AXC,2
                                TMIS
                                MFS
                CALL
                                MXM3
                VLOAD           STADR
                STOVL           MFI             +12D
                STADR
                STOVL           MFI             +6
                STADR
                STORE           MFI                     # MFI = TMIS MFS (SCALED BY 4)
                SETPD           CALL                    # TRANSPOSE MFI IN PD LIST

## Page 357
                                18D
                                TRNSPSPD
                VLOAD           STADR
                STOVL           TMFI            +12D
                STADR
                STOVL           TMFI            +6
                STADR
                STORE           TMFI                    # TMFI = TRANSPOSE (MFI) SCALED BY 4

# CALCULATE COFSKEW AND MFISYM

                DLOAD           DSU
                                TMFI            +2
                                MFI             +2
                PDDL            DSU                     # CALCULATE COF SCALED BY 2/SIN(AM)
                                MFI             +4
                                TMFI            +4
                PDDL            DSU
                                TMFI            +10D
                                MFI             +10D
                VDEF
                STORE           COFSKEW                 # EQUALS MFISKEW

# CALCULATE AM AND PROCEED ACCORDING TO ITS MAGNITUDE

                DLOAD           DAD
                                MFI
                                MFI             +16D
                DSU             DAD
                                DP1/4TH
                                MFI             +8D
                STORE           CAM                     # CAM = (MFI0+MFI4+MFI8-1)/2 HALF SCALE
                ARCCOS
                STORE           AM                      # AM=ARCCOS(CAM)  (AM SCALED BY 2)
                DSU             BPL
                                MINANG
                                CHECKMAX
                TLOAD                                   # MANEUVER LESS THAN .25 DEGREES
                                CPHI                    # GO DIRECTLY INTO ATTITUDE HOLD
                STCALL          CDUXD                   # ABOUT COMMANDED ANGLES
                                TOOBADI                 # STOP RATE AND EXIT

CHECKMAX        DLOAD           DSU
                                AM
                                MAXANG
                BPL             VLOAD
                                ALTCALC                 # UNIT
                                COFSKEW                 # COFSKEW
                UNIT
                STORE           COF                     # COF IS THE MANEUVER AXIS

## Page 358
                GOTO                                    # SEE IF MANEUVER GOES THRU GIMBAL LOCK
                                LOCSKIRT
ALTCALC         VLOAD           VAD                     # IF AM GREATER THAN 170 DEGREES
                                MFI
                                TMFI
                VSR1
                STOVL           MFISYM
                                MFI             +6
                VAD             VSR1
                                TMFI            +6
                STOVL           MFISYM          +6
                                MFI             +12D
                VAD             VSR1
                                TMFI            +12D
                STORE           MFISYM          +12D    # MFISYM=(MFI+TMFI)/2   SCALED BY 4


# CALCULATE COF


                DLOAD           SR1
                                CAM
                PDDL            DSU                     # PDO CAM                                $4
                                DPHALF
                                CAM
                BOVB            PDDL                    # PD2 1 - CAM                            $2
                                SIGNMPAC
                                MFISYM          +16D
                DSU             DDV
                                0
                                2
                SQRT            PDDL                    # COFZ = SQRT(MFISYM8-CAM)/1-CAM)
                                MFISYM          +8D     #                                $ ROOT 2
                DSU             DDV
                                0
                                2
                SQRT            PDDL                    # COFY = SQRT(MFISYM4-CAM)/(1-CAM)   $ROOT2
                                MFISYM
                DSU             DDV
                                0
                                2
                SQRT            VDEF                    # COFX = SQRT(MFISYM-CAM)/(1-CAM)   $ROOT 2
                UNIT
                STORE           COF

# DETERMINE LARGEST COF AND ADJUST ACCORDINGLY

COFMAXGO        DLOAD           DSU
                                COF
                                COF             +2
                BMN             DLOAD                   # COFY G COFX

## Page 359
                                COMP12
                                COF
                DSU             BMN
                                COF             +4
                                METHOD3                 # COFZ G COFX OR COFY
                GOTO
                                METHOD1                 # COFX G COFY OR COFZ
COMP12          DLOAD           DSU
                                COF             +2
                                COF             +4
                BMN
                                METHOD3                 # COFZ G COFY OR COFX

METHOD2         DLOAD           BPL                     # COFY MAX
                                COFSKEW         +2      # UY
                                U2POS
                VLOAD           VCOMP
                                COF
                STORE           COF
U2POS           DLOAD           BPL
                                MFISYM          +2      # UX UY
                                OKU21
                DLOAD           DCOMP                   # SIGN OF UX OPPOSITE TO UY
                                COF
                STORE           COF
OKU21           DLOAD           BPL
                                MFISYM          +10D    # UY UZ
                                LOCSKIRT
                DLOAD           DCOMP                   # SIGN OF UZ OPPOSITE TO UY
                                COF             +4
                STORE           COF             +4
                GOTO
                                LOCSKIRT
METHOD1         DLOAD           BPL                     # COFX MAX
                                COFSKEW                 # UX
                                U1POS
                VLOAD           VCOMP
                                COF
                STORE           COF
U1POS           DLOAD           BPL
                                MFISYM          +2      # UX UY
                                OKU12
                DLOAD           DCOMP
                                COF             +2      # SIGN OF UY OPPOSITE TO UX
                STORE           COF             +2
OKU12           DLOAD           BPL
                                MFISYM          +4      # UX UZ
                                LOCSKIRT
                DLOAD           DCOMP                   # SIGN OF UZ OPPOSITE TO UY
                                COF             +4

## Page 360
                STORE           COF             +4
                GOTO
                                LOCSKIRT
METHOD3         DLOAD           BPL                     # COFZ MAX
                                COFSKEW         +4      # UZ
                                U3POS
                VLOAD           VCOMP
                                COF
                STORE           COF
U3POS           DLOAD           BPL
                                MFISYM          +4      # UX UZ
                                OKU31
                DLOAD           DCOMP
                                COF                     # SIGN OF UX OPPOSITE TO UZ
                STORE           COF
OKU31           DLOAD           BPL
                                MFISYM          +10D    # UY UZ
                                LOCSKIRT
                DLOAD           DCOMP
                                COF             +2      # SIGN OF UY OPPOSITE TO UZ
                STORE           COF             +2
                GOTO
                                LOCSKIRT
## Page 361
# MATRIX OPERATIONS

                BANK            13
                SETLOC          KALCMON2
                BANK

                EBANK=          BCDU

MXM3            SETPD           VLOAD*                  # MXM3 MULTIPLIES 2 3X3 MATRICES
                                0                       # AND LEAVES RESULT IN PD LIST
                                0,1                     # AND MPAC
                VXM*            PDVL*
                                0,2
                                6,1
                VXM*            PDVL*
                                0,2
                                12D,1
                VXM*            PUSH
                                0,2
                RVQ


# RETURN WITH M1XM2 IN PD LIST

TRANSPOS        SETPD           VLOAD*                  # TRANSPOS TRANSPOSES A 3X3 MATRIX
                                0                       #  AND LEAVES RESULT IN PD LIST
                                0,1                     # MATRIX ADDRESS IN XR1
                PDVL*           PDVL*
                                6,1
                                12D,1
                PUSH                                    # MATRIX IN PD
TRNSPSPD        EXIT                                    # ENTER WITH MATRIX AT 0 IN PD LIST
                INDEX           FIXLOC
                DXCH            12
                INDEX           FIXLOC
                DXCH            16
                INDEX           FIXLOC
                DXCH            12
                INDEX           FIXLOC
                DXCH            14
                INDEX           FIXLOC
                DXCH            4
                INDEX           FIXLOC
                DXCH            14
                INDEX           FIXLOC
                DXCH            2
                INDEX           FIXLOC
                DXCH            6
                INDEX           FIXLOC
                DXCH            2

## Page 362
                TC              INTPRET
                RVQ

                BANK            15
                SETLOC          KALCMON1
                BANK

                EBANK=          BCDU

MINANG          2DEC            0.00069375
MAXANG          2DEC            0.472222222
# GIMBAL LOCK CONSTANTS

# D = MGA CORRESPONDING TO GIMBAL LOCK = 60 DEGREES
#          NGL = BUFFER ANGLE (TO AVOID DIVISIONS BY ZERO) = 2 DEGREES

SD              2DEC            .433015                 # = SIN(D)                        $2
K3S1            2DEC            .86603                  # = SIN(D)                        $1
K4              2DEC            -.25                    # = -COS(D)                       $2
K4SQ            2DEC            .125                    # = COS(D)COS(D)                  $2
SNGLCD          2DEC            .008725                 # = SIN(NGL)COS(D)                $2
CNGL            2DEC            .499695                 # COS(NGL)                        $2
LOCKANGL        DEC             .388889                 # = 70 DEGREES
# INTERPRETIVE SUBROUTINE TO READ THE CDU ANGLES

READCDUK        CA              CDUZ                    # LOAD T(MPAC) WITH CDU ANGLES
                TS              MPAC            +2
                EXTEND
                DCA             CDUX                    # AND CHANGE MODE TO TRIPLE PRECISION
                TCF             TLOAD           +6


CDUTODCM        AXT,1           SSP
                OCT             3
                                S1
                OCT             1                       # SET XR1, S1, AND PD FOR LOOP
                STORE           7
                SETPD
                                0
LOOPSIN         SLOAD*          RTB
                                10D,1
                                CDULOGIC

## Page 363
                STORE           10D                     # LOAD PD WITH  0 SIN(PHI)
                SIN             PDDL                    #               2 COS(PHI)
                                10D                     #               4 SIN(THETA)
                COS             PUSH                    #               6 COS(THETA)
                TIX,1           DLOAD                   #               8 SIN(PSI)
                                LOOPSIN                 #              10 COS(PSI)
                                6
                DMP             SL1
                                10D
                STORE           0,2                     # C0=COS(THETA)COS(PSI)
                DLOAD           DMP
                                4
                                0
                PDDL            DMP                     # (PD6 SIN(THETA)SIN(PHI))
                                6
                                8D
                DMP             SL1
                                2
                BDSU            SL1
                                12D
                STORE           2,2                     # C1=-COS(THETA)SIN(PSI)COS(PHI)
                DLOAD           DMP
                                2
                                4
                PDDL            DMP                     # (PD7 COS(PHI)SIN(THETA)) SCALED 4
                                6
                                8D
                DMP             SL1
                                0
                DAD             SL1
                                14D
                STORE           4,2                     # C2=COS(THETA)SIN(PSI)SIN(PHI)
                DLOAD
                                8D
                STORE           6,2                     # C3=SIN(PSI)
                DLOAD
                                10D
                DMP             SL1
                                2
                STORE           8D,2                    # C4=COS(PSI)COS(PHI)
                DLOAD           DMP
                                10D
                                0
                DCOMP           SL1
                STORE           10D,2                   # C5=-COS(PSI)SIN(PHI)
                DLOAD           DMP
                                4
                                10D
                DCOMP           SL1
                STORE           12D,2                   # C6=-SIN(THETA)COS(PSI)

## Page 364
                DLOAD
                DMP             SL1                     #  (PUSH UP 7)
                                8D
                PDDL            DMP                     #  (PD7 COS(PHI)SIN(THETA)SIN(PSI)) SCALE4
                                6
                                0
                DAD             SL1                     #  (PUSH UP 7)
                STADR                                   # C7=COS(PHI)SIN(THETA)SIN(PSI)
                STORE           14D,2                   #  +COS(THETA)SIN(PHI)
                DLOAD
                DMP             SL1                     #  (PUSH UP 6)
                                8D
                PDDL            DMP                     #  (PD6 SIN(THETA)SIN(PHI)SIN(PSI)) SCALE4
                                6
                                2
                DSU             SL1                     #  (PUSH UP 6)
                STADR
                STORE           16D,2                   # C8=-SIN(THETA)SIN(PHI)SIN(PSI)
                RVQ                                     #  +COS(THETA)COS(PHI)

# CALCULATION OF THE MATRIX DEL......

#          *      *               --T           *
#          DEL = (IDMATRIX)COS(A)+UU (1-COS(A))+UX SIN(A)         SCALED 1

#                -
#          WHERE U IS A UNIT VECTOR (DP SCALED 2) ALONG THE AXIS OF ROTATION.
#          A IS THE ANGLE OF ROTATION (DP SCALED 2)
#                                             -
#          UPON ENTRY THE STARTING ADDRESS OF U IS COF, AND A IS IN MPAC

DELCOMP         SETPD           PUSH                    # MPAC CONTAINS THE ANGLE A
                                0
                SIN             PDDL                    # PD0 = SIN(A)
                COS             PUSH                    # PD2 = COS(A)
                SR2             PDDL                    # PD2 = COS(A)				  $8
                BDSU            BOVB
                                DPHALF
                                SIGNMPAC
                PDDL                                    # PD4 = 1-COS(A)

# COMPUTE THE DIAGONAL COMPONENTS OF DEL

                                COF
                DSQ             DMP
                                4
                DAD             SL3
                                2
                BOVB
                                SIGNMPAC

## Page 365
                STODL           KEL                     # UX UX(1-COS(A)) +COS(A)                $1
                                COF             +2
                DSQ             DMP
                                4
                DAD             SL3
                                2
                BOVB
                                SIGNMPAC
                STODL           KEL             +8D     # UY UY(1-COS(A)) +COS(A)                $1
                                COF             +4
                DSQ             DMP
                                4
                DAD             SL3
                                2
                BOVB
                                SIGNMPAC
                STORE           KEL             +16D    # UZ UZ(1-COS(A)) +COS(A)                $1

# COMPUTE THE OFF DIAGONAL TERMS OF DEL

                DLOAD           DMP
                                COF
                                COF             +2
                DMP             SL1
                                4
                PDDL            DMP                     # D6  UX UY (1-COS A)                 $ 4
                                COF             +4
                                0
                PUSH            DAD                     # D8  UZ SIN A                        $ 4
                                6
                SL2             BOVB
                                SIGNMPAC
                STODL           KEL             +6
                BDSU            SL2
                BOVB
                                SIGNMPAC
                STODL           KEL             +2
                                COF
                DMP             DMP
                                COF             +4
                                4
                SL1             PDDL                    # D6  UX UZ (1-COS A)                 $ 4
                                COF             +2
                DMP             PUSH                    # D8  UY SIN(A)
                                0
                DAD             SL2
                                6
                BOVB
                                SIGNMPAC
                STODL           KEL             +4      # UX UZ (1-COS(A))+UY SIN(A)

## Page 366
                BDSU            SL2
                BOVB
                                SIGNMPAC
                STODL           KEL             +12D    # UX UZ (1-COS(A))-UY SIN(A)
                                COF             +2
                DMP             DMP
                                COF             +4
                                4
                SL1             PDDL                    # D6  UY UZ (1-COS(A))                $ 4
                                COF
                DMP             PUSH                    # D8  UX SIN(A)
                                0
                DAD             SL2
                                6
                BOVB
                                SIGNMPAC
                STODL           KEL             +14D    # UY UZ(1-COS(A)) +UX SIN(A)
                BDSU            SL2
                BOVB
                                SIGNMPAC
                STORE           KEL             +10D    # UY UZ (1-COS(A)) -UX SIN(A)
                RVQ


# DIRECTION COSINE MATRIX TO CDU ANGLE ROUTINE
# X1 CONTAINS THE COMPLEMENT OF THE STARTING ADDRESS FOR MATRIX (SCALED 2)
# LEAVES CDU ANGLES SCALED 2PI IN V(MPAC)
# COS(MGA) WILL BE LEFT IN S1 (SCALED 1)

# THE DIRECTION COSINE MATRIX RELATING S/C AXES TO STABLE MEMBER AXES CAN BE WRITTEN AS***

#          C =COS(THETA)COS(PSI)
#           0
#          C =-COS(THETA)SIN(PSI)COS(PHI)+SI (THETA)SIN(PHI)
#           1
#          C =COS(THETA)SIN(PSI)SIN(PHI) + S N(THETA)COS(PHI)
#           2
#          C =SIN(PSI)
#           3
#          C =COS(PSI)COS(PHI)
#           4
#          C =-COS(PSI)SIN(PHI)
#           5
#          C =-SIN(THETA)COS(PSI)
#           6
#          C =SIN(THETA)SIN(PSI)COS(PHI)+COS THETA)SIN(PHI)
#           7
#          C =-SIN(THETA)SIN(PSI)SIN(PHI)+CO (THETA)COS(PHI)
#           8

## Page 367

#          WHERE PHI = OGA
#                THETA = IGA
#                PSI = MGA

DCMTOCDU        DLOAD*          ARCSIN
                                6,1
                PUSH            COS                     # PD +0   PSI
                SL1             BOVB
                                SIGNMPAC
                STORE           S1
                DLOAD*          DCOMP
                                12D,1
                DDV             ARCSIN
                                S1
                PDDL*           BPL                     # PD +2  THETA
                                0,1                     # MUST CHECK THE SIGN OF COS(THETA)
                                OKTHETA                 # TO DETERMINE THE PROPER QUADRANT
                DLOAD           DCOMP
                BPL             DAD
                                SUHALFA
                                DPHALF
                GOTO
                                CALCPHI
SUHALFA         DSU
                                DPHALF
CALCPHI         PUSH
OKTHETA         DLOAD*          DCOMP
                                10D,1
                DDV             ARCSIN
                                S1
                PDDL*           BPL                     # PUSH DOWN PHI
                                8D,1
                                OKPHI
                DLOAD           DCOMP                   # PUSH UP PHI
                BPL             DAD
                                SUHALFAP
                                DPHALF
                GOTO
                                VECOFANG
SUHALFAP        DSU             GOTO
                                DPHALF
                                VECOFANG
OKPHI           DLOAD                                   # PUSH UP PHI
VECOFANG        VDEF            RVQ

## Page 368
# ROUTINES FOR TERMINATING THE AUTOMATIC MANEUVER AND RETURNING TO USER

TOOBADF         EXIT
                TC              ALARM
                OCT             00401

                TCF             NOGO                    # DO NOT ZERO ATTITUDE ERRORS

                TC              BANKCALL
                CADR            ZATTEROR                # ZERO ATTITUDE ERRORS

NOGO            TC              BANKCALL
                CADR            STOPRATE                # STOP RATES

                CAF             TWO
                INHINT                                  # ALL RETURNS ARE NOW MADE VIA GOODEND
                TC              WAITLIST
                EBANK=          BCDU
                2CADR           GOODMANU

                TCF             ENDOFJOB

TOOBADI         EXIT
                TCF             NOGO
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