### FILE="Main.annotation"
## Copyright:   Public domain.
## Filename:    KALCMANU_STEERING.agc
## Purpose:     A section of Luminary revision 163.
##              It is part of the reconstructed source code for the first
##              (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 173, as well as Luminary memos 157 amd 158.
##              It has been adapted such that the resulting bugger words
##              exactly match those specified for Luminary 163 in NASA
##              drawing 2021152N, which gives relatively high confidence
##              that the reconstruction is correct.
## Reference:   pp. 370-374
## Assembler:   yaYUL
## Contact:     Ron Burkey <info@sandroid.org>.
## Website:     www.ibiblio.org/apollo/index.html
## Mod history: 2019-08-21 MAS  Created from Luminary 173.

## Page 370
# GENERATION OF STEERING COMMANDS FOR DIGITAL AUTOPILOT FREE FALL MANEUVERS

# NEW COMMANDS WILL BE GENERATED EVERY ONE SECOND DURING THE MANEUVER

                EBANK=          TTEMP

NEWDELHI        TC              BANKCALL                # CHECK FOR AUTO STABILIZATION
                CADR            ISITAUTO                # ONLY
                CCS             A
                TCF             NOGO            -2
NEWANGL         TC              INTPRET
                AXC,1           AXC,2
                                MIS                     # COMPUTE THE NEW MATRIX FROM S/C TO
                                KEL                     # STABLE MEMBER AXES
                CALL
                                MXM3
                VLOAD           STADR
                STOVL           MIS             +12D    # CALCULATE NEW DESIRED CDU ANGLES
                STADR
                STOVL           MIS             +6D
                STADR
                STORE           MIS
                AXC,1           CALL
                                MIS
                                DCMTOCDU                # PICK UP THE NEW CDU ANGLES FROM MATRIX
                RTB
                                V1STO2S
                STORE           NCDU                    # NEW CDU ANGLES
                BONCLR          EXIT
                                CALCMAN2
                                MANUSTAT                # TO START MANEUVER
                CAF             TWO                     #          +0 OTHERWISE
INCRDCDU        TS              SPNDX
                INDEX           SPNDX
                CA              BCDU                    # INITIAL CDU ANGLES
                EXTEND                                  # OR PREVIOUS DESIRED CDU ANGLES
                INDEX           SPNDX
                MSU             NCDU
                EXTEND
                SETLOC          KALCMON1
                BANK

                MP              DT/TAU
                CCS             A                       # CONVERT TO 2S COMPLEMENT
                AD              ONE
                TCF             +2
                COM
                INDEX           SPNDX
                TS              DELDCDU                 # ANGLE INCREMENTS TO BE ADDED TO
                INDEX           SPNDX                   # CDUXD, CDUYD, CDUZD EVERY TENTH SECOND

## Page 371
                CA              NCDU                    # BY LEM DAP
                INDEX           SPNDX
                XCH             BCDU
                INDEX           SPNDX
                TS              CDUXD
                CCS             SPNDX
                TCF             INCRDCDU                # LOOP FOR THREE AXES

                RELINT

# COMPARE PRESENT TIME WITH TIME TO TERMINATE MANEUVER

TMANUCHK        TC              TIMECHK
                TCF             CONTMANU
                CAF             ONE
MANUSTAL        INHINT                                  # END MAJOR PART OF MANEUVER WITHIN 1 SEC
                TC              WAITLIST                # UNDER WAITLIST CALL TO MANUSTOP
                EBANK=          TTEMP
                2CADR           MANUSTOP

                RELINT
                TCF             ENDOFJOB

TIMECHK         EXTEND
                DCS             TIME2
                DXCH            TTEMP
                EXTEND
                DCA             TM
                DAS             TTEMP
                CCS             TTEMP
                TC              Q
                TCF             +2
                TCF             2NDRETRN
                CCS             TTEMP           +1
                TC              Q
                TCF             MANUOFF
                COM
MANUOFF         AD              ONESEK          +1
                EXTEND
                BZMF            2NDRETRN
                INCR            Q
2NDRETRN        INCR            Q
                TC              Q

DT/TAU          DEC             .1

MANUSTAT        EXIT                                    # INITIALIZATION ROUTINE
                EXTEND                                  # FOR AUTOMATIC MANEUVERS
                DCA             TIME2
## Page 372
                DAS             TM                      # TM+T0    MANEUVER COMPLETION TIME
                EXTEND
                DCS             ONESEK
                DAS             TM                      # (TM+T0)-1
                INHINT
                CAF             TWO
RATEBIAS        TS              KSPNDX
                DOUBLE
                TS              KDPNDX
                INDEX           A
                CA              BRATE
                INDEX           KSPNDX                  # STORE MANEUVER RATE IN
                TS              OMEGAPD                 # OMEGAPD, OMEGAQD, OMEGARD
                EXTEND
                BZMF            +2                      # COMPUTE ATTITUDE ERROR
                COM                                     # OFFSET = (WX)ABS(WX)/2AJX
                EXTEND                                  # WHERE AJX= 2-JET ACCELERATION
                MP              BIASCALE                # = -1/16
                EXTEND
                INDEX           KDPNDX
                MP              BRATE
                EXTEND
                INDEX           KSPNDX
                DV              1JACC                   # =AJX  $ 90 DEG/SEC-SEC
                INDEX           KSPNDX
                TS              DELPEROR                #     $ 180 DEG
                CCS             KSPNDX
                TCF             RATEBIAS

                CA              TIME1
                AD              ONESEK          +1
                XCH             NEXTIME
                TCF             INCRDCDU        -1

ONESEK          DEC             0
                DEC             100

BIASCALE        OCT             75777                   # = -1/16

CONTMANU        CS              TIME1                   # RESET FOR NEXT DCDU UPDATE
                AD              NEXTIME
                CCS             A
                AD              ONE
                TCF             MANUCALL
                AD              NEGMAX
                COM
MANUCALL        INHINT                                  # CALL FOR NEXT UPDATE VIA WAITLIST
                TC              WAITLIST
                EBANK=          TTEMP
                2CADR           UPDTCALL

## Page 373
                CAF             ONESEK          +1      # INCREMENT TIME FOR NEXT UPDATE
                ADS             NEXTIME
                TCF             ENDOFJOB


UPDTCALL        CAF             PRIO26                  # SATELLITE PROGRAM TO CALL FOR UPDATE
                TC              FINDVAC                 # OF STEERING COMMANDS
                EBANK=          TTEMP
                2CADR           NEWDELHI

                TC              TASKOVER

## Page 374
# ROUTINE FOR TERMINATING AUTOMATIC MANEUVERS

MANUSTOP        CAF             ZERO                    # ZERO MANEUVER RATES
                TS              DELDCDU2
                TS              OMEGARD
                TS              DELREROR
                TS              DELDCDU1
                TS              OMEGAQD
                TS              DELQEROR
                CA              CPSI                    # SET DESIRED GIMBAL ANGLES TO
                TS              CDUZD                   # DESIRED FINAL GIMBAL ANGLES
                CA              CTHETA
                TS              CDUYD
ENDROLL         CA              CPHI                    # NO FINAL YAW
                TS              CDUXD
                CAF             ZERO
                TS              OMEGAPD                 # I.E. MANEUVER DID NOT GO THRU
                TS              DELDCDU                 # GIMBAL LOCK ORIGINALLY
                TS              DELPEROR
GOODMANU        CA              ATTPRIO                 # RESTORE USERS PRIO
                TS              NEWPRIO

                CA              ZERO                    # ZERO ATTCADR
                DXCH            ATTCADR

                TC              SPVAC                   # RETURN TO USER

                TC              TASKOVER