Revision 3577d0b1de1ac147c1710524517c563b2bfe231c authored by Ronald Burkey on 30 May 2021, 19:14:00 UTC, committed by GitHub on 30 May 2021, 19:14:00 UTC
Issue 1143: Fix various symbol name and other minor typos
LUNAR_LANDING_GUIDANCE_EQUATIONS.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: LUNAR_LANDING_GUIDANCE_EQUATIONS.agc
## Purpose: A section of LUM69 revision 2.
## It is part of the reconstructed source code for the flown
## version of the flight software for the Lunar Module's (LM)
## Apollo Guidance Computer (AGC) for Apollo 10. The code has
## been recreated from a copy of Luminary revsion 069, using
## changes present in Luminary 099 which were described in
## Luminary memos 75 and 78. The code has been adapted such
## that the resulting bugger words exactly match those specified
## for LUM69 revision 2 in NASA drawing 2021152B, which gives
## relatively high confidence that the reconstruction is correct.
## Reference: pp. 802-828
## Assembler: yaYUL
## Contact: Ron Burkey <info@sandroid.org>.
## Website: www.ibiblio.org/apollo/index.html
## Mod history: 2019-07-27 MAS Created from Luminary 69.
## 2021-05-30 ABS Removed DEC66 symbol not present in Luminary 69.
## Page 802
EBANK= E2DPS
COUNT* $$/F2DPS
# ****************************************************************************************************************
# LUNAR LANDING FLIGHT SEQUENCE TABLES
# ****************************************************************************************************************
# FLIGHT SEQUENCE TABLES ARE ARRANGED BY FUNCTION. THEY ARE REFERENCED USING AS AN INDEX THE REGISTER WCHPHASE:
# WCHPHASE = -1 ---> IGNALG
# WCHPHASE = 0 ---> BRAKQUAD
# WCHPHASE = 1 ---> BRAKLING
# WCHPHASE = 2 ---> APPRQUAD
# WCHPHASE = 3 ---> APPRLING
# WCHPHASE = 4 ---> VERTICAL
# ***************************************************************************************************************
# ROUTINES FOR STARTING NEW GUIDANCE PHASES:
TCF TTFINCR # IGNALG
NEWPHASE TCF TTFINCR # BRAKQUAD
TCF LINSET? # BRAKLING
TCF STARTP64 # APPRQUAD
TCF LINSET # APPRLING
TCF P65START # VERTICAL
#
# PRE-GUIDANCE COMPUTATIONS:
TCF CALCRGVG # IGNALG
PREGUIDE TCF RGVGCALC # BRAKQUAD
TCF RGVGCALC # BRAKLING
TCF REDESIG # APPRQUAD
TCF RGVGCALC # APPRLING
TCF RGVGCALC # VERTICAL
#
# GUIDANCE EQUATIONS:
TCF TTF/8CL # IGNALG
WHATGUID TCF TTF/8CL # BRAKQUAD
TCF LINGUID # BRAKLING
TCF TTF/8CL # APPRQUAD
TCF LINGUID # BRAKLING
TCF VERTGUID # VERTICAL
## Page 803
# POST GUIDANCE EQUATION COMPUTATIONS:
TCF CGCALC # IGNALG
AFTRGUID TCF CGCALC # BRAKQUAD
TCF LINXLOGC # BRAKLING
TCF CGCALC # APPRQUAD
TCF LINXLOGC # APPRLING
TCF EXVERT # VERTICAL
#
# WINDOW VECTOR COMPUTATIONS:
TCF EXGSUB # IGNALG
WHATEXIT TCF EXBRAK # BRAKQUAD
TCF EXBRAK # BRAKLING
TCF EXNORM # APPRQUAD
TCF EXNORM # APPRLING
#
# DISPLAY ROUTINES:
WHATDISP TCF P63DISPS # BRAKQUAD
TCF P63DISPS # BRAKLING
TCF P64DISPS # APPRQUAD
TCF P64DISPS # APPRLING
TCF VERTDISP # VERTICAL
#
# INDICES FOR REFERENCING TARGET PARAMETERS:
OCT 0 # IGNALG
TARGTDEX OCT 0 # BRAKQUAD
OCT 0 # BRAKLING
OCT 30 # APPRQUAD
OCT 30 # APPRLING
#
# ****************************************************************************************************************
# ENTRY POINTS: 2GUIDSUB FOR THE IGNITION ALGORITHM, LUNLAND FOR SERVOUT
# ****************************************************************************************************************
# IGNITION ALGORITHM ENTRY: DELIVERS N PASSES OF QUADRATIC QUIDANCE
?GUIDSUB EXIT
CAF TWO # N = 3
TS NGUIDSUB
TCF GUILDRET
GUIDSUB TS NGUIDSUB # ON SUCEEDING PASSES SKIP TTFINCR
TCF CALCRGVG
## Page 804
# NORMAL ENTRY: CONTROL COMES HERE FROM SERVOUT
LUNLAND TC PHASCHNG
OCT 00035 # GROUP 5: RETAIN ONLY PIPA TASK
TC PHASCHNG
OCT 05023 # GROUP 3: PROTECT GUIDANCE WITH PRIO 21
OCT 21000 # JUST HIGHER THAN SERVICER'S PRIORITY
# ****************************************************************************************************************
# GUILDENSTERN: AUTO-MODES MONITOR (R13)
# ****************************************************************************************************************
COUNT* $$/R13
# HERE IS THE PHILOSOPHY OF GUILDENSTERN: ON EVERY APPEARANCE OR DISAPPEARANCE OF THE MANUAL THROTTLE
# DISCRETE TO SELECT P67 OR P66 RESPECTIVELY; ON EVERY APPEARANCE OF THE ATTITUDE-HOLD DISCRETE TO SELECT P66
# UNLESS THE CURRENT PROGRAM IS P67 IN WHICH CASE THERE IS NO CHANGE.
GUILDEN EXTEND # IS UN-AUTO-THROTTLE DISCRETE PRESENT?
STERN READ CHAN30
MASK BIT5
CCS A
TCF STARTP67 # YES
P67NOW? TC CHECKMM # NO: ARE WE IN P67 NOW?
DEC 67
TCF STABL? # NO
STARTP66 TC FASTCHNG # YES
TC NEWMODEX
DEC 66
EXTEND # INITIALIZE VDGVERT USING
DCA VGU # PRESENT DOWNWARD VELOCITY
DXCH VDGVERT
CAF ZERO
TS RODCOUNT
VRTSTART TS WCHVERT
CAF FOUR # WCHPHASE = 4 --> VERTICAL: P65,P66,P67
TS WCHPHOLD
TS WCHPHASE
TC BANKCALL # TEMPORARY, I HOPE HOPE HOPE
CADR STOPRATE # TEMPORARY, I HOPE HOPE HOPE
TC DOWNFLAG # PERMIT X-AXIS OVERRIDE
ADRES XOVINFLG
TC DOWNFLAG
ADRES REDFLAG
TC DOWNFLAG
ADRES POUTFLAG # PERMIT PULSE-OUTS
TCF GUILDRET
STARTP67 TC NEWMODEX # NO HARM IN "STARTING" P67 OVER AND OVER
DEC 67 # SO NO NEED FOR A FASTCHNG AND NO NEED
## Page 805
CAF TEN # TO SEE IF ALREADY IN P67
TCF VRTSTART
STABL? CAF BIT13 # IS UN-ATTITUDE-HOLD DISCRETE PRESENT?
EXTEND
RAND CHAN31
CCS A
TCF GUILDRET # YES: ALL'S WELL
P66NOW? TC CHECKMM # NO: ARE WE IN P66 NOW?
DEC 66
TCF STARTP66 # NO
# (CONTINUE TO GUILDRET) YES
# ****************************************************************************************************************
# INITIALIZATION FOR THIS PASS
# ****************************************************************************************************************
COUNT* $$/F2DPS
GUILDRET EXTEND
DCA TPIP
DXCH TPIPOLD
TC FASTCHNG
EXTEND
DCA PIPTIME1
DXCH TPIP
EXTEND
DCA TTF/8
DXCH TTF/8TMP
CCS FLPASS0
TCF TTFINCR
BRSPOT1 INDEX WCHPHASE
TCF NEWPHASE
# ****************************************************************************************************************
# ROUTINES TO START NEW PHASES
# ****************************************************************************************************************
P65START TC NEWMODEX
DEC 65
CS TWO
TS WCHVERT
TC DOWNFLAG # PERMIT X-AXIS OVERRIDE
ADRES XOVINFLG
## Page 806
COMSTART TC DOWNFLAG
ADRES POUTFLAG
TCF TTFINCR
STARTP64 CAF DELTTFAP # AUGMENT TTF/8 (TWO-PHASE ONLY)
ADS TTF/8TMP
+2 TC NEWMODEX
DEC 64
CAF TWO
TS WCHPHASE
CA BIT12 # ENABLE RUPT10
EXTEND
WOR CHAN13
TC DOWNFLAG # INITIALIZE REDESIGNATION FLAG
ADRES REDFLAG
TCF COMSTART
# ****************************************************************************************************************
# SET LINEAR GUIDANCE COEFFICIENTS
# ****************************************************************************************************************
LINSET? CA FLAGWRD6 # ONE-PHASE OR TWO-PHASE?
MASK 2PHASBIT
EXTEND
BZF STARTP64 +2 # ONE-PHASE: GO DIRECTLY TO APPROACH PHASE
LINSET TC INTPRETX
VLOAD VSU* # - - -
ACG # JLING = (ACG - ADG)/TTF
ADG,1
VSR3 V/SC
TTF/8TMP # TTF/8 NOT YET UPDATED
STORE JLING # JLING IS IN UMITS OF 2(-18) M/CS/CS/CS
EXIT
# (CONTINUE TO TTFINCR)
# ****************************************************************************************************************
# INCREMENT TTF/8, UPDATE LAND FOR LUNAR ROTATION, DO OTHER USEFUL THINGS
# ****************************************************************************************************************
#
# TTFINCR COMPUTATIONS ARE AS FOLLOWS:-
# TTF/8 UPDATED FOR TIME SINCE LAST PASS:
# TTF/8 = TTF/8 + (TPIP - TPIPOLD)/8
# LANDING SITE VECTOR UPDATED FOR LUNAR ROTATION:
## Page 807
# - - - -
# LAND = /LAND/ UNIT(LAND - LAND(TPIP - TPIPOLD) * WM)
# SLANT RANGE TO LANDING SITE, FOR DISPLAY:
# - -
# RANGEDSP = ABVAL(LAND - R)
TTFINCR TC INTPRET
DLOAD DSU
TPIP
TPIPOLD
SLR PUSH # SHIFT SCALES DELTA TIME TO 2(17) CSECS
11D
VXSC VXV
LAND
WM
BVSU RTB
LAND
NORMUNIT
VXSC VSL1
/LAND/
STORE LANDTEMP
VSU ABVAL
R
STODL RANGEDSP
EXIT
DXCH MPAC
DAS TTF/8TMP # NOW HAVE INCREMENTED TTF/8 IN TTF/8TMP
TC FASTCHNG
EXTEND
DCA TTF/8TMP
DXCH TTF/8
EXTEND
DCA LANDTEMP
DXCH LAND
EXTEND
DCA LANDTEMP +2
DXCH LAND +2
EXTEND
DCA LANDTEMP +4
DXCH LAND +4
TC TDISPSET
TC FASTCHNG # SINCE REDESIG MAY CHANGE LANDTEMP
## Page 808
BRSPOT2 INDEX WCHPHASE
TCF PREGUIDE
# ****************************************************************************************************************
# LANDING SITE PERTURBATION EQUATIONS
# ****************************************************************************************************************
REDESIG CA FLAGWRD6 # IS REDFLAG SET?
MASK REDFLBIT
EXTEND
BZF RGVGCALC # NO: SKIP REDESIGNATION LOGIC
CA TREDES # YES: HAS TREDES REACHED ZERO?
EXTEND
BZF RGVGCALC # YES: SKIP REDESIGNATION LOGIC
INHINT
CA ELINCR1
TS ELINCR
CA AZINCR1
TS AZINCR
TC FASTCHNG
CA ZERO
TS ELINCR1
TS AZINCR1
RELINT
TS ELINCR +1
TS AZINCR +1
CA FIXLOC # SET PD TO 0
TS PUSHLOC
TC INTPRET
VLOAD VSU
LAND
R # - -
RTB PUSH # PUSH DOWN UNIT (LAND - R)
NORMUNIT
VXV VSL1
YNBPIP # - - -
VXSC PDDL # PUSH DOWN - ELINCR(YNB * UNIT(LAND - R))
ELINCR
AZINCR
VXSC VSU
YNBPIP
VAD PUSH # RESULTING VECTOR IS 1/2 REAL SIZE
DLOAD DSU # MAKE SURE REDESIGNATION IS NOT
0 # TOO CLOSE TO THE HORIZON
## Page 809
DEPRCRIT
BMN DLOAD
REDES1
DEPRCRIT
STORE 0
REDES1 DLOAD DSU
LAND
R
DDV VXSC
0
VAD UNIT
R
VXSC VSL1
/LAND/
STORE LANDTEMP
EXIT # LOOKANGL WILL BE COMPUTED AT RGVGCALC
TC FASTCHNG
EXTEND
DCA LANDTEMP
DXCH LAND
EXTEND
DCA LANDTEMP +2
DXCH LAND +2
EXTEND
DCA LANDTEMP +4
DXCH LAND +4
TCF RGVGCALC
# ****************************************************************************************************************
# COMPUTE STATE IN GUIDANCE COORDINATES
# ****************************************************************************************************************
# RGVGCALC COMPUTATIONS ARE AS FOLLOWS:-
# VELOCITY RELATIVE TO THE SURFACE:
# - - - -
# ANGTERM = V + R * WM
# STATE IN GUIDANCE COORDINATES:
# - * - -
# RGU = CG (R - LAND)
# - * - - -
# VGU = CG (V - WM * R)
## Page 810
# HORIZONTAL VELOCITY FOR DISPLAY:
# VHORIZ = 8 ABVAL (0, VG , VG )
# 2 1
# DEPRESSION ANGLE FOR DISPLAY:
# - - -
# LOOKANGL = ARCSIN(UNIT(R - LAND).XMBPIP)
CALCRGVG TC INTPRET # IN IGNALG, COMPUTE V FROM INTEGRATION
VLOAD MXV # OUTPUT AND TRIM CORRECTION TERM
VATT1 # COMPUTED LAST PASS AND LEFT IN UNFC/2
REFSMMAT
VSR1 VAD
UNFC/2
STORE V
EXIT
RGVGCALC TC INTPRET # ENTER HERE TO RECOMPUTE RG AND VG
VLOAD VXV
R
WM
VAD VSR2 # RESCALE TO UNITS OF 2(9) M/CS
V
STORE ANGTERM
MXV
CG # NO SHIFT SINCE ANGTERM IS DOUBLE SIZED
STORE VGU
PDDL VDEF # FORM (0,VG ,VG ) IN UNITS OF 2(10) M/CS
ZEROVECS # 2 1
ABVAL SL3
STOVL VHORIZ # VHORIZ FOR DISPLAY DURING P65, P66, P67
R # - -
VSU PUSH # PUSH DOWN R - LAND
LAND
MXV VSL1
CG
STOVL RGU
RTB DOT # NOW IN MPAC IS SINE(LOOKANGL)/4
NORMUNIT
XNBPIP
EXIT
CA FIXLOC # RESET PUSH DOWN POINTER
TS PUSHLOC
CA MPAC # COMPUTE LOOKANGL ITSELF
DOUBLE
TC BANKCALL
## Page 811
CADR SPARCSIN -1
AD 1/2DEG
EXTEND
MP 180DEGS
TS LOOKANGL # LOOKANGL FOR DISPLAY DURING P64
BRSPOT3 INDEX WCHPHASE
TCF WHATGUID
#****************************************************************************************************************
# LINEAR GUIDANCE EQUATION
#****************************************************************************************************************
LINGUID TC INTPRETX
VLOAD VXSC # - - -
JLING # ACG = ADG + JLING TTF
TTF/8
VSL3 GOTO # PICK UP THE VAD* AT AFCCALC
AFCCALC
#****************************************************************************************************************
# TTF/4 COMPUTATION
#****************************************************************************************************************
TTF/8CL TC INTPRETX
DLOAD*
JDG2TTF,1
STODL* TABLTTF +6 # A(3) = 8 JDG TO TABLTTF
ADG2TTF,1 # 2
STODL TABLTTF +4 # A(2) = 6 ADG TO TABLTTF
VGU +4 # 2
DMP DAD*
3/4DP
VDG2TTF,1
STODL* TABLTTF +2 # A(1) = (6 VGU + 18 VDG )/8 TO TABLTTF
RDG +4,1 # 2 2
DSU DMP
RGU +4
3/8DP
STORE TABLTTF # A(0) = -24 (RGU - RDG )/64 TO TABLTTF
EXIT # 2 2
CA BIT8
TS TABLTTF +10 # FRACTIONAL PRECISION FOR TTF TO TABLE
EXTEND
DCA TTF/8
DXCH MPAC # LOADS TTF/8 (INITIAL GUESS) INTO MPAC
CAF TWO # DEGREE - ONE
TS L
## Page 812
CAF TABLTTFL
TC ROOTPSRS # YIELDS TTF/8 IN MPAC
TC POODOO # BAD RETURN
OCT 01406
EXTEND # GOOD RETURN
DCA MPAC # FETCH TTF/8 KEEPING IT IN MPAC
DXCH TTF/8 # CORRECTED TTF/8
TC TDISPSET
# (CONTINUE TO QUADGUID)
# ****************************************************************************************************************
# MAIN GUIDANCE EQUATION
# ****************************************************************************************************************
# AS PUBLISHED:-
# - - - -
# - - 6(VDG + VG) 12(RDG - RG)
# ACG = ADG + ----------- + ------------
# TTF (TTF)(TTF)
# AS HERE PROGRAMMED:-
# - -
# 3 (1/4(RDG - RG) - - )
# - (------------- + VDG + VG)
# - 4 ( TTF/8 ) -
# ACG = ---------------------------- + ADG
# TTF/8
QUADGUID CAF 30SEC*17 # PULSE-OUTS ARE INHIBITED WHENEVER
AD TTF/8 # TTF < 30 SECONDS, REGARDLESS OF
EXTEND # THE DURATION OF LINEAR GUIDANCE
BZMF Q**DG**D
TC UPFLAG
ADRES POUTFLAG
Q**DG**D TC INTPRETX
VLOAD* VSU
RDG,1
RGU
V/SC VSR2
TTF/8
VAD* VAD
VDG,1
VGU
V/SC VXSC
TTF/8
## Page 813
3/4DP
AFCCALC VAD*
ADG,1 # CURRENT TARGET ACCELERATION
STORE ACG
AFCCALC1 VXM VSL1 # VERTGUID COMES HERE
CG
PDVL V/SC
GDT/2
GSCALE
BVSU STADR
STORE UNFC/2 # UNFC/2 NEED NOT BE UNITIZED
ABVAL
AFCCALC2 STORE /AFC/ # MAGNITUDE OF AFC FOR THROTTLE
BON DLOAD
2PHASFLG
AFCCLEND
UNFC/2 # VERTICAL COMPONENT
DSQ PDDL
UNFC/2 +2 # OUT-OF-PLANE
DSQ PDDL
HIGHESTF
DDV DSQ
MASS # 2 2 2
DSU DSU # AMAXHORIZ = SQRT(ATOTAL - A - A )
BPL DLOAD # 1 0
AFCCALC3
ZEROVECS
AFCCALC3 SQRT DAD
UNFC/2 +4
BPL BDSU
AFCCLEND
UNFC/2 +4
STORE UNFC/2 +4
AFCCLEND EXIT
TC FASTCHNG
CA WCHPHASE # PREPARE FOR PHASE SWITCHING LOGIC
TS WCHPHOLD
INCR FLPASS0 # INCREMENT PASS COUNTER
BRSPOT4 INDEX WCHPHASE
TCF AFTRGUID
# ***************************************************************************************************************
# ERECT GUIDANCE-STABLE MEMBER TRANSFORMATION MATRIX
# ***************************************************************************************************************
CGCALC TC INTPRET
VLOAD UNIT
LAND
## Page 814
STOVL CG # FIRST ROW
ANGTERM
VXSC VAD # REMEMBER THAT ANGTERM IS DOUBLE-SIZED
TTF/8
LAND
VSU RTB
R
NORMUNIT
VXV RTB
LAND
NORMUNIT
STOVL CG +6 # SECOND ROW
CG
VXV VSL1
CG +6
STORE CG +14
EXIT
# (CONTINUE TO EXTLOGIC)
# ****************************************************************************************************************
# PREPARE TO EXIT
# ****************************************************************************************************************
# DECIDE (1) HOW TO EXIT, AND (2) WHETHER TO SWITCH PHASES
EXTLOGIC CCS WCHPHASE
INDEX A # WCHPHASE = +2 APPRQUAD A = 1
CA TENDBRAK # WCHPHASE = +0 BRAKQUAD A = 0
TCF EXSPOT1 -1 # WCHPHASE = -1 IGNALG A = 0
LINXLOGC CA 3SEC*17
AD TTF/8
EXSPOT1 EXTEND
INDEX WCHPHASE
BZMF WHATEXIT
TC FASTCHNG
CA WCHPHOLD
AD ONE
ZL # +0
DXCH WCHPHASE # ADVANCING WCHPHASE AND RESETTING FLPASS0
INDEX WCHPHOLD
TCF WHATEXIT
# ****************************************************************************************************************
# ROUTINES FOR EXITING FROM LANDING GUIDANCE
## Page 815
# ****************************************************************************************************************
# 1. EXGSUB IS THE RETURN WHEN GUIDSUB IS CALLED BY THE IGNITION ALGORITHM.
# 2. EXBRAK IN THE EXIT USED DURING THE BRAKING PHASE. IN THIS CASE UNIT(R) IS THE WINDOW POINTING VECTOR.
# 3. EXNORM IS THE EXIT USED AT OTHER TIMES DURING THE BURN.
# (EXOVFLOW IS A SUBROUTINE OF EXBRAK AND EXNORM CALLED WHEN OVERFLOW OCCURRED ANYWHERE IN GUIDANCE.)
EXGSUB TC INTPRET # COMPUTE TRIM VELOCITY CORRECTION TERM
VLOAD RTB
UNFC/2
NORMUNIT
VXSC VXSC
ZOOMTIME
TRIMACCL
STORE UNFC/2
EXIT
CCS NGUIDSUB
TCF GUIDSUB
CCS NIGNLOOP
TCF +3
TC ALARM
OCT 01412
+3 TC POSTJUMP
CADR DDUMCALC
EXBRAK TC INTPRET
VLOAD
UNIT/R/
STORE UNWC/2
EXIT
TCF STEER?
EXNORM TC INTPRET
VLOAD VSU
LAND
R
RTB
NORMUNIT
STORE UNWC/2 # UNIT(LAND - R) IS TENTATIVE CHOICE
VXV DOT
XNBPIP
CG +6
EXIT # WITH PROJ IN MPAC 1/8 REAL SIZE
CS MPAC # GET COEFFICIENT FOR CG +14
## Page 816
AD PROJMAX
AD POSMAX
TS BUF
CS BUF
ADS BUF # RESULT IS 0 IF PROJMAX - PROJ NEGATIVE
CS PROJMIN # GET COEFFICIENT FOR UNIT(LAND - R)
AD MPAC
AD POSMAX
TS BUF +1
CS BUF +1
ADS BUF +1 # RESULT IS 0 IF PROJ - PROJMIN NEGATIVE
CAF FOUR
UNWCLOOP MASK SIX
TS Q
CA EBANK5
TS EBANK
EBANK= CG
CA BUF
EXTEND
INDEX Q
MP CG +14
INCR BBANK
EBANK= UNWC/2
INDEX Q
DXCH UNWC/2
EXTEND
MP BUF +1
INDEX Q
DAS UNWC/2
CCS Q
TCF UNWCLOOP
INCR BBANK
EBANK= PIF
STEER? CA FLAGWRD2 # IF STEERSW DOWN NO OUTPUTS
MASK STEERBIT
EXTEND
BZF RATESTOP
EXVERT CA OVFIND # IF OVERFLOW ANYWHERE IN GUIDANCE
EXTEND # DON'T CALL THROTTLE OR FINDCDUW
BZF +6
EXOVFLOW TC ALARM # SOUND THE ALARM NON-ABORTIVELY.
OCT 01410
RATESTOP TC BANKCALL # CLEAN UP AFTER LAST FINDCDUW
## Page 817
CADR STOPRATE
TCF DISPEXIT
GDUMP1 TC THROTTLE
TC INTPRET
CALL
FINDCDUW -2
EXIT
# (CONTINUE TO DISPEXIT)
# ****************************************************************************************************************
# GUIDANCE LOOP DISPLAYS
# ****************************************************************************************************************
DISPEXIT EXTEND # KILL GROUP 3: DISPLAYS WILL BE
DCA NEG0 # RESTORED BY NEXT GUIDANCE CYCLE
DXCH -PHASE3
CS FLAGWRD8 # IF FLUNDISP SET, NO DISPLAY THIS PASS
MASK FLUNDBIT
EXTEND
BZF ENDLLJOB # TO PICK UP THE TAG
INDEX WCHPHOLD
TCF WHATDISP
-2 TC PHASCHNG # KILL GROUP 5
OCT 00035
P63DISPS CAF V06N63
DISPCOMN TC BANKCALL
CADR REGODSPR
ENDLLJOB TCF ENDOFJOB
P64DISPS CA TREDES # HAS TREDES REACHED ZERO?
EXTEND
BZF RED-OVER # YES: CLEAR REDESIGNATION FLAG
CS FLAGWRD6 # NO: IS REDFLAG SET?
MASK REDFLBIT
EXTEND
BZF REDES-OK # YES: DO STATIC DISPLAY
CAF V06N64 # OTHERWISE USE FLASHING DISPLAY
TC BANKCALL
## Page 818
CADR REFLASHR
TCF GOTOPOOH # TERMINATE
TCF P64CEED # PROCEED PERMIT REDESIGNATIONS
TCF P64DISPS # RECYCLE
TCF ENDLLJOB # TO PICK UP THE TAG
P64CEED CAF ZERO
TS ELINCR1
TS AZINCR1
TC UPFLAG # ENABLE REDESIGNATION LOGIC
ADRES REDFLAG
TCF ENDOFJOB
RED-OVER TC DOWNFLAG
ADRES REDFLAG
REDES-OK CAF V06N64
TCF DISPCOMN
VERTDISP CAF V06N60
TCF DISPCOMN
# ****************************************************************************************************************
# GUIDANCE FOR VERTICAL DESCENT
# ****************************************************************************************************************
VERTGUID CCS WCHVERT
TCF DISPEXIT # POSITIVE P67, WHICH SKIPS ALL GUIDANCE
TCF P66VERT # +0
# THE P65 GUIDANCE EQUATION IS AS FOLLOWS:-
# - -
# - VDGVERT - VGU -
# ACG = ------------- , WHERE VDGVERT = (-3FPS,0,0)
# TAUVERT
P65VERT EXTEND # NEGATIVE
DCS +3FPS
DXCH VDGVERT
TC INTPRET
VLOAD PDDL
ZEROVECS
VDGVERT
VDEF VSU # FORM (VDGVERT,0,0), LEAVING DP 0 IN PDL
VGU
## Page 819
V/SC GOTO
TAUVERT
AFCCALC1
# THE R.O.D. EQUATION IS AS FOLLOWS:-
# (VDGVERTX - VGUX)/TAUVERT - GMOON
# /AFC/ = ---------------------------------
# UNIT/R/ . XNB
P66VERT XCH RODCOUNT # RESTART COULD CAUSE RODCOUNTS TO BE LOST
EXTEND
MP +1FPS
DAS VDGVERT
TC FASTCHNG
TC INTPRET
DLOAD DSU
VDGVERT
VGU
DDV DSU
TAUROD
MOONG
PDVL DOT # HAVE ACC IN UNITS OF 2(-2) M/CS/CS
XNBPIP
UNIT/R/
BDDV STADR
STORE /AFC/
BOVB EXIT
EXOVFLOW
TC THROTTLE
TCF DISPEXIT
# ****************************************************************************************************************
# REDESIGNATOR TRAP
# ****************************************************************************************************************
BANK 21
SETLOC F2DPS*21
BANK
COUNT* $$/F2DPS
PITFALL XCH BANKRUPT
EXTEND
QXCH QRUPT
TC CHECKMM # IF NOT IN P64, NO REASON TO CONTINUE
DEC 64
## Page 820
TCF RESUME
EXTEND
READ CHAN31
COM
MASK ALL4BITS
TS ELVIRA
CAF TWO
TS ZERLINA
CAF FIVE
TC TWIDDLE
ADRES REDESMON
TCF RESUME
# REDESIGNATION MONITOR (INITIATED BY PITFALL)
PREMON1 TS ZERLINA
PREMON2 CAF SEVEN
TC VARDELAY
REDESMON EXTEND
READ 31
COM
MASK ALL4BITS
XCH ELVIRA
TS L
CCS ELVIRA # DO ANY BITS APPEAR THIS PASS?
TCF PREMON2 # Y: CONTINUE MONITOR
CCS L # N: ANY LAST PASS?
TCF COUNT'EM # Y: COUNT 'EM, RESET RUPT, TERMINATE
CCS ZERLINA # N: HAS ZERLINA REACHED ZERO YET?
TCF PREMON1 # N: DIMINISH ZERLINA, CONTINUE
RESETRPT CAF BIT12 # Y: RESET RUPT, TERMINATE
EXTEND
WOR CHAN13
TCF TASKOVER
COUNT'EM CA L
MASK -AZBIT
CCS A
-AZ CS AZEACH
ADS AZINCR1
CA L
MASK +AZBIT
CCS A
+AZ CA AZEACH
ADS AZINCR1
CA L
## Page 821
MASK -ELBIT
CCS A
-EL CS ELEACH
ADS ELINCR1
CA L
MASK +ELBIT
CCS A
+EL CA ELEACH
ADS ELINCR1
TCF RESETRPT
# THESE EQUIVALENCIES ARE BASED ON GSOP CHAPTER 4, REVISION 16 OF P64LM
+ELBIT = BIT2 # -PITCH
-ELBIT = BIT1 # +PITCH
+AZBIT = BIT5
-AZBIT = BIT6
ALL4BITS OCT 00063
AZEACH DEC .03491 # 2 DEGREES
ELEACH DEC .00873 # 1/2 DEGREE
# ****************************************************************************************************************
# R.O.D. TRAP
# ************************************************************************
BANK 20
SETLOC RODTRAP
BANK
COUNT* $$/F2DPS # ****************************************
DESCBITS MASK BIT7 # COME HERE FROM MARKRUPT CODING WITH BIT
CCS A # 7 OR 6 OF CHANNEL 16 IN A: BIT 7 MEANS
CS TWO # - RATE INCREMENT, BIT 6 + INCREMENT
AD ONE
ADS RODCOUNT
## Page 822
TCF RESUME # TRAP IS RESET WHEN SWITCH IS RELEASED
BANK 31
SETLOC F2DPS*31
BANK
COUNT* $$/F2DPS
# ****************************************************************************************************************
# DOUBLE PRECISION ROOT FINDER SUBROUTINE (BY ALLAN KLUMPP)
# ****************************************************************************************************************
# N N-1
# ROOTPSRS FINDS ONE ROOT OF THE POWER SERIES A X + A X + ... + A X + A
# N N-1 1 0
# USING NEWTON'S METHOD STARTING WITH AN INITIAL GUESS FOR THE ROOT. THE ENTERING DATA MUST BE AS FOLLOWS:
# A SP LOC-3 ADRES FOR REFERENCING PWR COF TABL
# L SP N-1 N IS THE DEGREE OF THE POWER SERIES
# MPAC DP X INITIAL GUESS FOR ROOT
# LOC-2N DP A(0)
# ...
# LOC DP A(N)
# LOC+2 SP PRECROOT PREC RQD OF ROOT (AS FRACT OF 1ST GUESS)
# THE DP RESULT IS LEFT IN MPAC UPON EXIT, AND A SP COUNT OF THE ITERATIONS TO CONVERGENCE IS LEFT IN MPAC+2.
# RETURN IS NORMALLY TO LOC(TC ROOTPSRS)+3. IF ROOTPSRS FAILS TO CONVERGE IN 32 PASSES, RETURN IS TO LOC+1 AND
# OUTPUTS ARE NOT TO BE TRUSTED.
# PRECAUTION: ROOTPSRS MAKES NO CHECKS FOR OVERFLOW OR FOR IMPROPER USAGE. IMPROPER USAGE COULD
# PRECLUDE CONVERGENCE OR REQUIRE EXCESSIVE ITERATIONS. AS A SPECIFIC EXAMPLE, ROOTPSRS FORMS A DERIVATIVE
# COEFFICIENT TABLE BY MULTIPLYING EACH A(I) BY I, WHERE I RANGES FROM 1 TO N. IF AN ELEMENT OF THE DERIVATIVE
# COEFFICIENT TABLE = 1 OR > 1 IN MAGNITUDE, ONLY THE EXCESS IS RETAINED. ROOTPSRS MAY CONVERGE ON THE CORRECT
# ROOT NONETHELESS, BUT IT MAY TAKE AN EXCESSIVE NUMBER OF ITERATIONS. THEREFORE THE USER SHOULD RECOGNIZE:
# 1. USER'S RESPONSIBILITY TO ASSURE THAT I X A(I) < 1 IN MAGNITUDE FOR ALL I.
# 2. USER'S RESPONSIBILITY TO ASSURE OVERFLOW WILL NOT OCCUR IN EVALUATING EITHER THE RESIDUAL OR THE DERIVATIVE
# POWER SERIES. THIS OVERFLOW WOULD BE PRODUCED BY SUBROUTINE POWRSERS, CALLED BY ROOTPSRS, AND MIGHT NOT
# PRECLUDE EVENTUAL CONVERGENCE.
# 3. AT PRESENT, ERASABLE LOCATIONS ARE RESERVED ONLY FOR N UP TO 5. AN N IN EXCESS OF 5 WILL PRODUCE CHAOS.
# ALL ERASABLES USED BY ROOTPSRS ARE UNSWITCHED LOCATED IN THE REGION FROM MPAC-33 OCT TO MPAC+7.
# 4. THE ITERATION COUNT RETURNED IN MPAC+2 MAY BE USED TO DETECT ABNORMAL PERFORMANCE.
# STORE ENTERING DATA, INITLIZE ERASABLES
## Page 823
ROOTPSRS EXTEND
QXCH RETROOT # RETURN ADRES
TS PWRPTR # PWR TABL POINTER
DXCH MPAC +3 # PWR TABL ADRES, N-1
CA DERTABLL
TS DERPTR # DER TABL POINTER
TS MPAC +5 # DER TABL ADRES
CCS MPAC +4 # NO POWER SERIES OF DEGREE 1 OR LESS
TS MPAC +6 # N-2
CA ZERO # MODE USED AS ITERATION COUNTER. MODE
TS MODE # MUST BE POS SO ABS WON'T COMP MPAC+3 ETC
# COMPUTE CRITERION TO STOP ITERATING
EXTEND
DCA MPAC # FETCH ROOT GUESS, KEEPING IT IN MPAC
DXCH ROOTPS # AND IN ROOTPS
INDEX MPAC +3 # PWR TABL ADRES
CA 5 # PRECROOT TO A
TC SHORTMP # YIELDS DP PRODUCT IN MPAC
TC USPRCADR
CADR ABS # YIELDS ABVAL OF CRITERION ON DX IN MPAC
DXCH MPAC
DXCH DXCRIT # CRITERION
# SET UP DER COF TABL
EXTEND
INDEX PWRPTR
DCA 3
DXCH MPAC # A(N) TO MPAC
CA MPAC +4 # N-1 TO A
DERCLOOP TS PWRCNT # LOOP COUNTER
AD ONE
TC DMPNSUB # YIELDS DERCOF = I X A(I) IN MPAC
EXTEND
INDEX PWRPTR
DCA 1
DXCH MPAC # A(I-1) TO MPAC, FETCHING DERCOF
INDEX DERPTR
DXCH 3 # DERCOF TO DER TABL
CS TWO
ADS PWRPTR # DECREMENT PWR POINTER
CS TWO
ADS DERPTR # DECREMENT DER POINTER
CCS PWRCNT
TCF DERCLOOP
## Page 824
# CONVERGE ON ROOT
ROOTLOOP EXTEND
DCA ROOTPS # FETCH CURRENT ROOT
DXCH MPAC # LEAVE IN MPAC
EXTEND
DCA MPAC +5 # LOAD A, L WITH DER TABL ADRES, N-2
TC POWRSERS # YIELDS DERIVATIVE IN MPAC
EXTEND
DCA ROOTPS
DXCH MPAC # CURRENT ROOT TO MPAC, FETCHING DERIVTIVE
DXCH BUF # LEAVE DERIVATIVE IN BUF AS DIVISOR
EXTEND
DCA MPAC +3 # LOAD A, L WITH PWR TABL ADRES, N-1
TC POWRSERS # YIELDS RESIDUAL IN MPAC
TC USPRCADR
CADR DDV/BDDV # YIELDS -DX IN MPAC
EXTEND
DCS MPAC # FETCH DX, LEAVING -DX IN MPAC
DAS ROOTPS # CORRECTED ROOT NOW IN ROOTPS
TC USPRCADR
CADR ABS # YIELDS ABS(DX) IN MPAC
EXTEND
DCS DXCRIT
DAS MPAC # ABS(DX)-ABS(DXCRIT) IN MPAC
INCR MODE # INCREMENT ITERATION COUNTER
CA MODE
MASK BIT4 # KLUMPP SAYS GIVE UP AFTER EIGHT PASSES
CCS A
BADROOT TC RETROOT
CCS MPAC # TEST HI ORDER DX
TCF ROOTLOOP
TCF TESTLODX
TCF ROOTSTOR
TESTLODX CCS MPAC +1 # TEST LO ORDER DX
TCF ROOTLOOP
TCF ROOTSTOR
TCF ROOTSTOR
ROOTSTOR DXCH ROOTPS
DXCH MPAC
CA MODE
TS MPAC +2 # STORE SP ITERATION COUNT IN MPAC+2
INDEX RETROOT
TCF 2
## Page 825
DERTABLL ADRES DERCOFN -3
# ****************************************************************************************************************
# TRASHY LITTLE SUBROUTINES
# ****************************************************************************************************************
INTPRETX INDEX WCHPHASE # SET X1 ON THE WAY TO THE INTERPRETER
CS TARGTDEX
INDEX FIXLOC
TS X1
TCF INTPRET
TDISPSET CA TTF/8
EXTEND
MP TSCALINV
DXCH TTFDISP
CA TTF/8
EXTEND
MP SCTTFDSP
TS L
AD 99+LINT
EXTEND
BZMF +11
CS L
AD -LINT
EXTEND
BZMF +3
TS TREDES
TC Q
CA ZERO
TCF -3
CA 99+LINT
TCF -10
# ****************************************************************************************************************
# SPECIALIZED "PHASCHNG" SUBROUTINE
# ****************************************************************************************************************
EBANK= PHSNAME2
FASTCHNG CA EBANK3 # SPECIALIZED 'PHASCHNG' ROUTINE
XCH EBANK
DXCH L
TS PHSNAME3
LXCH EBANK
## Page 826
EBANK= E2DPS
TC A
# ****************************************************************************************************************
# PARAMETER TABLE INDIRECT ADDRESSES
# ****************************************************************************************************************
RDG = RBRFG
VDG = VBRFG
ADG = ABRFG
VDG2TTF = VBRFG*
ADG2TTF = ABRFG*
JDG2TTF = JBRFG*
# ****************************************************************************************************************
# LUNAR LANDING CONSTANTS
# ***************************************************************************************************************
3SEC*17 DEC +3 E2 B-17
10SEC*17 DEC +10 E2 B-17
20SEC*17 DEC +20 E2 B-17
30SEC*17 DEC +30 E2 B-17
TABLTTFL ADRES TABLTTF +3 # ADDRESS FOR REFERENCING TTF TABLE
HIGHESTF 2DEC +43245 E-4 B-12# THRUST FOR RADIAL CONTROL
TTFSCALE = BIT12
TSCALINV = BIT4
99+LINT DEC +119
-LINT DEC -20
SCTTFDSP DEC .08 # RESCALES FROM 2(-17) CS TO WHOLE SECONDS
## Page 827
180DEGS DEC +180
1/2DEG DEC +.00278
DELTTFAP DEC -158 E2 B-17
TAUVERT 2DEC 600 B-14
TAUROD 2DEC 300 B-12
GSCALE 2DEC 100 B-11
3/8DP 2DEC .375000000
3/4DP 2DEC .750000000
+1FPS DEC .3048 E-2 B+4
+3FPS 2DEC +0.9144 E-2 B-10
DEPRCRIT 2DEC -.02 B-2 # DEPRESSION ANGLE CRITERION
PROJMAX DEC .42262 B-3 # SIN(25')/8 TO COMPARE WITH PROJ
PROJMIN DEC .25882 B-3 # SIN(15')/8 TO COMPARE WITH PROJ
V06N63 VN 0663 # P63
V06N64 VN 0664 # P64
V06N60 VN 0660 # P65, P66, P67
## Page 828
# ****************************************************************************************************************
# ****************************************************************************************************************
Computing file changes ...
