P40-P47.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: P40-P47.agc
## Purpose: A section of Luminary revision 116.
## It is part of the source code for the Lunar Module's (LM)
## Apollo Guidance Computer (AGC) for Apollo 12.
## This file is intended to be a faithful transcription, except
## that the code format has been changed to conform to the
## requirements of the yaYUL assembler rather than the
## original YUL assembler.
## Reference: pp. 745-777
## Assembler: yaYUL
## Contact: Ron Burkey <info@sandroid.org>.
## Website: www.ibiblio.org/apollo/index.html
## Mod history: 2017-01-22 MAS Created from Luminary 99.
## 2017-03-10 RSB Transcribed, and then proofed comment-text using
## 3-way diff vs Luminary 99 and Luminary 131.
## (Admittedly, the former is more for detecting errors
## in Luminary 99 than the other way around.)
## 2017-03-16 RSB Comment-text fixes identified in 5-way
## side-by-side diff of Luminary 69/99/116/131/210.
## 2017-08-16 RSB Fixed comment typo identified in AP11ROPE.
## 2017-08-26 MAS Fixed an incorrect label found while transcribing
## Zerlina 56 (it was unreferenced so caused no errors).
## Page 745
# PROGRAM DESCRIPTION P40BOTH DECEMBER 22, 1966
# MOD 03 BY PETER ADLER MARCH 3, 1967
# CALLED VIA JOB FROM V37E
# FUNCTIONAL DESCRIPTION
# 1) TO COMPUTE A PREFERRED IMU ORIENTATION AND A PREFERRED VEHICLE ATTITUDE FOR A LM DPS
# THRUSTING MANEUVER.
# 3) TO DO THE VEHICLE MANEUVER TO THE THRUSTING ATTITUDE.
# 4) TO CONTROL THE PGNCS DURING COUNTDOWN, IGNITION, THRUSTING, AND THRUST TERMINATION OF A
# PGNCS CONTROLLED DPS MANEUVER.
# 5) IN POSTBURN--ZERO RENDEZVOUS COUNTER, MAINTAIN VG CALCULATIONS FOR POSSIBLE RCS MANEUVER,
# SET MAXIMUM DEADBAND IN DAP, RESET STEERLAW CSTEER TO ZERO.
# NOTE: P42, WHICH IS IN THIS LOG SECTION, DOES THE SAME FOR AN APS BURN, AND P41 DOES 1-3 FOR
# RCS PLUS DISPLAYS PARAMETERS FOR MANUAL CONTROL.
# SUBROUTINES USED
# R02 IMU STATUS CHECK
# S40.1 COMPUTATION OF THRUST DIRECTION
# S40.13 LENGTH OF BURN
# S40.2,3 PREFERRED IMU ORIENATTION
# S40.8 X PRODUCT STEERING
# S40.9 LAMBERT VTOGAIN
# R60LEM ATTITUDE MANEUVER
# LEMPREC EXTRAPOLATE STATE VECTOR
# PREREAD AVERAGE G, SERVICER
# ALLCOAST DAP COASTING INITIALIZATION
# CLOKTASK ERGO CLOCKJOB -- COUNT DOWN
# PHASCHNG, INTPRET, FLAGUP, FLAGDOWN, WAITLIST, LONGCALL, GOFLASH, GOFLASHR, GOPERF1, ALARM,
# PRIOLARM, GOTOPOOH, ENDOFJOB, BANKCALL, SETMAXDB, SETMINDB, CHECKMM, FLATOUT, OUTFLAT,
# KILLTASK, SGNAGREE, TPAGREE, ETC.
# RESTARTS VIA GROUP 4
# DISPLAYS
# V50N25 203 A/P TO PGNCS, AUTOTHROTTLE MODE, AUTO ATTITUDE CONTROL
# V06N40 TTI, VG, DELTAVM (DISPLAYED ONCE/SECOND BY CLOKTASK)
# V50N99 PLEASE PERFORM ENGINE ON ENABLE
# V06N40 TG (TIME TO GO TO CUTOFF), VG, DELTAVM -- ONCE/SECOND
# V16N40 FINAL VALUES OF TG, VG, DELTAVM
# V16N85 COMP OF VG (BODY AXES) FOR POSS. RCS MANUAL MANEUVER
# V05N09 POSSIBLE ALARMS
# V50N07 PLEASE SELECT P00
## Page 746
# VIA R30
# V06N44 HAPO, PERI, TFF
# V06N35 TIME TO PERIGEE, HMS
# ALARM OR ABORT EXIT MODES
# PROGRAM ALARM, FLASHING DISPLAY OF ALARM CODE 1706 IF P40 SELECTED WITH DESCENT UNIT STAGED.
# V34E (TERMINATE) IS THE ONLY RESPONSE ACCEPTED. TC GOTOPOOH.
# PROGRAM ALARM, FLASH CODE 1703: TIG LESS THAN 45 SECS AWAY. V34E= GOTOPOOH OR V33E= SLIP
# TIG BY 45 SECS.
# ERASABLE INITIALIZATION
# DEBRIS
# OUTPUT
# SEE SUBROUTINES E.G.: S40.1, S40.2,3, S40.13, S40.8, S40.9, TRIMGIMB
# XDELVFLG = 1 FOR EXT DELV COMPUTATION
# = 0 FOR AIMPT (LAMBERT) COMP
COUNT* $$/P40
EBANK= WHICH
BANK 36
SETLOC P40S
BANK
P40LM TC PHASCHNG
OCT 04024
CAF P40ADRES # INITIALIZATION FOR BURNBABY.
TS WHICH
CA FLGWRD10
MASK APSFLBIT
CCS A
TCF P40ALM
TC BANKCALL # GO DO IMU STATUS CHECK ROUTINE.
CADR R02BOTH
CS DAPBOOLS # INITIALIZE DVMON
MASK CSMDOCKD
CCS A
CAF THRESH1
AD THRESH3
TS DVTHRUSH
CAF FOUR
TS DVCNTR
## Page 747
TC INTPRET # LOAD CONSTANTS FOR DPS BURN
VLOAD CLEAR # LOAD F, MDOT, TDECAY
FDPS
NOTHROTL
STORE F
SLOAD
DPSVEX
P40IN DCOMP SR1
STCALL VEX # LOAD EXHAUST VELOCITY FOR TGO COMP.
S40.1 # COMPUTES UT AND VGTIG
CALL
S40.2,3 # COMPUTES PREFERRED IMU ORIENTATION
EXIT
INHINT
TC IBNKCALL
CADR PFLITEDB # ZERO ATTITUDE ERRORS, SET DB TO ONE DEG.
TC P40SXT4
# ***********************
TCF BURNBABY
# ***********************
P40SXT4 EXTEND
QXCH P40/RET
P41MANU RELINT
TC DOWNFLAG # CLEAR 3AXISFLG -- R60 WILL USE VECPOINT.
ADRES 3AXISFLG
TC BANKCALL
CADR R60LEM # DO ATTITUDE MANEUVER ROUTINE
TC P40/RET
EBANK= TRKMKCNT
POSTBURN CA Z
TS DISPDEX
EXTEND
DCA ACADN85
DXCH AVEGEXIT
CAF V16N40
TC BANKCALL
CADR GOFLASHR
TC TERM40
TCF TIGNOW
TC POSTBURN
## Page 748
P40PHS1 TC PHASCHNG
OCT 00014
TCF ENDOFJOB
TIGNOW INHINT
TC IBNKCALL
CADR ZATTEROR
TC IBNKCALL
CADR SETMINDB
RELINT
CAF V16N85B
TC BANKCALL
CADR REFLASHR
TC TERM40
TCF TERM40
TC -5
TCF P40PHS1
TERM40 EXTEND
DCA SERVCADR
DXCH AVEGEXIT
CAF ZERO
TS TRKMKCNT # ZERO RENDZVS CNTERS
CA Z
TS DISPDEX
INHINT
TC IBNKCALL
CADR RESTORDB
RELINT
TC GOTOPOOH
EBANK= WHICH
COUNT* $$/P41
P41LM CAF P41ADRES # INITIALIZATION FOR BURNBABY
TS WHICH
TC BANKCALL
CADR R02BOTH
TC INTPRET # BOTH LM
BON DLOAD # IF NJETSFLAG IS SET, LOAD 2 JET F
NJETSFLG
P41FJET1
FRCS4 # IF NJETSFLAG IS CLEAR, LOAD 4 JET F
P41FJET STCALL F
P41IN
P41FJET1 DLOAD
## Page 749
FRCS2
STORE F
P41IN CALL
S40.1 # BOTH
P41NORM CALL
S40.2,3 # CALCULATE PREFERRED IMU ORIENTATION AND
EXIT # SET PFRATFLG.
INHINT
TC IBNKCALL
CADR ZATTEROR # ZERO ATTITUDE ERRORS
TC IBNKCALL
CADR SETMINDB # SET 0.3 DEGREE DEADBAND
TC P40SXT4
TC INTPRET
VLOAD CALL # TRANSFORM VELOCITY-TO-BE-GAINED AT TIG
VGTIG # FROM REFERENCE COORDINATES TO LM BODY-
S41.1 # AXIS COORDINATES FOR V16N85 DISPLAY.
STORE VGBODY # (SCALED AT 2 (+7) METERS/CENTISECOND)
EXIT
CAF V16N85B
TC BANKCALL
CADR GODSPRET
CAF PRIO5
TS DISPDEX # FOR SAFETY ONLY
TC FINDVAC
EBANK= VGPREV
2CADR DYNMDISP
TC 2PHSCHNG
OCT 00076 # GROUP 6 RESTARTS AT REDO6.7
OCT 04024 # GROUP 4 RESTARTS HERE
# ***********************
TCF B*RNB*B*
# ***********************
BLNKWAIT CAF 1SEC
TC BANKCALL
CADR DELAYJOB
REDO6.7 CA DISPDEX # ON A RESTART, DO NOT PUT UP DISPLAY IF
AD TWO # BLANKING (BETWEEN TIG-35 AND TIG-30)
# ***********************
## Page 750
EXTEND
BZF BLNKWAIT
CAF V16N85B
TC BANKCALL
CADR GODSPRET
CAF PRIO5
TC PRIOCHNG
DYNMDISP CA DISPDEX # A NON-POSITIVE DISPDEX INDICATES PAST
EXTEND # TIG-35, SO SERVICER WILL BE DOING THE
BZMF ENDOFJOB # UPDATING OF NOUN 85. STOP DYNMDISP.
TC INTPRET
VLOAD CALL
VGPREV
S41.1
STORE VGBODY
EXIT
CAF 1SEC
TC BANKCALL
CADR DELAYJOB
TCF DYNMDISP
CALCN85 TC INTPRET
CALL
UPDATEVG
VLOAD CALL
VGPREV
S41.1
STORE VGBODY
EXIT
TC POSTJUMP
CADR SERVEXIT
COUNT* $$/P42
EBANK= WHICH
P42LM TC PHASCHNG
OCT 04024
CAF P42ADRES # INITIALIZATION FOR BURNBABY.
TS WHICH
CS FLGWRD10
MASK APSFLBIT
CCS A
TC P40ALM
P42STAGE TC BANKCALL
## Page 751
CADR R02BOTH
CAF THRESH2 # INITIALIZE DVMON
TS DVTHRUSH
CAF FOUR
TS DVCNTR
TC INTPRET
SET VLOAD # LOAD FAPS, MDOTAPS, AND ATDECAY INTO
AVFLAG # F, MDOT, AND TDECAY BY VECTOR LOAD.
FAPS
STORE F
SLOAD GOTO
APSVEX
P40IN
EBANK= WHICH
COUNT* $$/P47
P47LM TC BANKCALL
CADR R02BOTH
TC INTPRET
CALRB
MIDTOAV2
CA MPAC +1
TC TWIDDLE
ADRES STARTP47
TCF ENDOFJOB
STARTP47 TC PHASCHNG
OCT 05014
OCT 77777
EXTEND
DCA ACADN83
DXCH AVEGEXIT
CAF PRIO20
TC FINDVAC
EBANK= DELVIMU
2CADR P47BODY
TCF REDO4.2 # CHECKS PHASE 5 AND GOES TO PREREAD
# SEE TIG-30 IN BURNBABY.
CALCN83 TC INTPRET
VLOAD VAD
DELVCTL
DELVREF
STORE DELVSIN # TEMP STORAGE FOR RESTARTS
## Page 752
CALL
S41.1
STORE DELVIMU
EXIT
TC PHASCHNG
OCT 10035 # REREADAC AND HERE
TC INTPRET
VLOAD
DELVSIN
STORE DELVCTL
EXIT
TC POSTJUMP
CADR SERVEXIT
P47BOD CAF V1683
TC BANKCALL
CADR GOFLASHR
TC GOTOPOOH
TC GOTOPOOH
TCF P47BODY
TCF P40PHS1
P47BODY TC INTPRET
VLOAD
HI6ZEROS
STORE DELVIMU
STORE DELVCTL
EXIT
TC P47BOD
COUNT* $$/P40
IMPLBURN CA TGO +1
TC GETDT
TC TWIDDLE
ADRES ENGOFTSK
TC DOWNFLAG # TURN OFF IGNFLAG
ADRES IGNFLAG
TC DOWNFLAG # TURN OFF ASTNFLG
ADRES ASTNFLAG
TC DOWNFLAG # TURN OFF IMPULSW
ADRES IMPULSW
TC PHASCHNG # RESTART PROTECT ENGOFTSK (ENGINOFF)
OCT 40114
TC FIXDELAY # WAIT HALF A SECOND
DEC 50
## Page 753
TC NOULLAGE # TURN OFF ULLAGE
TC TASKOVER
ENGOFTSK TC IBNKCALL # THIS CODING ALLOWS ENGINOFF ET AL TO BE
CADR ENGINOFF # USED BOTH BY WAITLIST AND BY TC IBNKCALL
TC TASKOVER
ENGINOFF CAF PRIO12 # MUST BE LOWER PRIO THAN CLOCKJOB
TC FINDVAC
EBANK= TRKMKCNT
2CADR POSTBURN
ENGINOF2 CAF BIT1
TC WAITLIST
EBANK= OMEGAQ
2CADR COASTSET
ENGINOF1 CS FLAGWRD7 # SET THE IDLE BIT.
MASK IDLEFBIT
ADS FLAGWRD7
TC NOULLAGE
ENGINOF4 EXTEND
DCA TIME2
DXCH TEVENT
ENGINOF3 CS ENGONBIT # INSURE ENGONFLG IS CLEAR.
MASK FLAGWRD5
TS FLAGWRD5
CS PRIO30 # ENGINOF3 IS USED AS A PRE-ENGINE ARM
EXTEND # SUBROUTINE.
RAND DSALMOUT
AD PRIO20 # TURN OFF THE ENGINE - DPS OR APS
EXTEND
WRITE DSALMOUT
CS DAPBOOLS # TURN OFF TRIM GIMBAL
MASK USEQRJTS
ADS DAPBOOLS
CS HIRTHROT # ZERO AUTO-THROTTLE WHENEVER THE ENGINE
TS THRUST # IS TURNED OFF.
CAF BIT4 # THE HARDWARE DOES SO ONLY WHEN THE
EXTEND # ENGINE IS DISARMED.
WOR CHAN14
TC ISWRETRN
## Page 754
COASTSET TC IBNKCALL # DO DAP COASTING INITIALIZATION
CADR ALLCOAST
TC TASKOVER
EBANK= OMEGAQ
UPDATEVG STQ CALL
QTEMP1
S40.8 # X-PRODUCT STEERING
BON BON
XDELVFLG
QTEMP1
NORMSW
180SETUP
DLOAD DSU
PIPTIME
TIGSAVE
DSU BMN
TNEWA
GETRANS
DLOAD DAD
TIGSAVE
TNEWA
STORE TIGSAVEP
180SETUP EXIT
CCS PHASE2
TCF NO.9
CAF PRIO10
INHINT
TC FINDVAC
EBANK= VG
2CADR S40.9 # LAMBERT VTOGAIN
TC 2PHSCHNG
OCT 00172 # 2.17SPOT FOR S40.9
OCT 10035 # HERE AND REREADAC AFTER RESTART
ENDSTEER TC INTPRET
DLOAD
TIGSAVEP
STOVL TIGSAVE
RN
STOVL RINIT
VN
STORE VINIT
GETRANS DLOAD DSU
TPASS4
PIPTIME
STCALL DELLT4
QTEMP1
## Page 755
NO.9 TC INTPRET
GOTO
QTEMP1
STEERING TC INTPRET
CALL
UPDATEVG
EXIT
EBANK= DVCNTR
NSTEER INHINT
CA EBANK7
TS EBANK
CS FLAGWRD2 # CHECK IMPULSE SWITCH. IT IS SET EITHER
MASK IMPULBIT # BY S40.13 IF TBURN<6 SECS OR BY S40.8 IF
CCS A # STEERING IS ALMOST DONE.
TCF +5 # IMPULSW = 0 EXIT
CS FLAGWRD7 # IMPULSW = 1 WHY? CHECK IDLEFLAG
MASK IDLEFBIT # (IDLEFLAG = 0 --> DVMON ON)
CCS A
TCF +3 # DVMON ON --> THRUSTING --> IMPULSW VIA S40.8
TC POSTJUMP # DVMON OFF --> IMPULSW ON VIA S40.13 --> EXIT
CADR SERVEXIT
TC IBNKCALL
CADR STOPRATE
TC DOWNFLAG # TURN OFF IMPULSW
ADRES IMPULSW
TC UPFLAG
ADRES IDLEFLAG # TURN OFF DVMON
INHINT
EXTEND
DCA TIG
DXCH MPAC
EXTEND
DCS TIME2
DAS MPAC
TC TPAGREE
CAE MPAC +1
TC GETDT
TC TWIDDLE
ADRES ENGOFTSK
TC 2PHSCHNG
OCT 40114 # ENGOFTSK (ENGINOFF)
OCT 00035 # SERVICER -- REREADAC
## Page 756
TCF ENDOFJOB
GETDT CCS A
TCF +3
TCF +2
CAF ZERO
AD ONE
XCH L
CAF ZERO
DXCH TGO
CA TGO +1
TC Q
# ************************************************************************
SEC15DP OCT 00000 # DON'T SEPARATE
SEC15 DEC 1500 # DON'T SEPARATE
SEC30DP 2DEC 3000
SEC45DP OCT 00000 # DON'T MOVE FROM JUST BEFORE SEC45
SEC45 DEC 4500
5SECDP OCT 00000 # DON'T MOVE FROM JUST BEFORE 5SEC
5SEC DEC 500
26SECS DEC 2600
V16N40 VN 1640
V16N85B VN 1685
V1683 VN 1683
SEC01 = 1SEC
ACADN85 = P41TABLE +2
EBANK= DELVIMU
ACADN83 2CADR CALCN83
# *************************************************
## Page 757
# PROGRAM DESCRIPTION S40.1 DATE 15NOV66
# MOD N02 LOG SECTION P40-P47
# MOD BY ZELDIN AND ADAPTED BY TALAYCO
# FUNCTIONAL DESCRIPTION
# COMPUTE INITIAL THRUST DIRECTION(UT) AND INITIAL VALUE OF VG
# VECTOR(VGTIG).
# CALLING SEQUENCE
# L CALL
# L+1 S40.1
# NORMAL EXIT MODE
# AT L+2 OF CALLING SEQUENCE (GOTO L+2) NORMAL RETURN OR
# ERROR RETURN IF NOSOFLAG =1
# SUBROUTINES CALLED
# LEMPREC
# INITVEL
# CALCGRAV
# MIDGIM
# ALARM OR ABORT EXIT MODES
# L+2 OF CALLING SEQUENCE, UNSOLVABLE CONIC IF NOSOFLAG=1
# ERASABLE INITIALIZATION REQUIRED
# WEIGHT/G ANTICIPATED VEHICLE MASS DP B16 KGM
# XDELVFLG 1=DELTA-V MANEUVER, 0=AIMPT STEER
# F THRUST FOR ENGINE USED
# IF DELTA-V MANEUVER
# DELVSIN SPECIFIED DELTA-V REQUIRED IN
# INERTIAL COORDS. OF ACTIVE VEHICLE
# AT TIME OF IGNITION VECTOR B7 M/CS
# DELVSAB MAG. OF DELVSIN DP B7 M/CS
# RTIG POSITION AT TIME OF IGNITION VECTOR B29 M
# VTIG VELOCITY AT TIME OF IGNITION VECTOR B7 M/CS
# IF AIMPT STEER
# TIG TIME OF IGNITION DP B28 CS
# RTARG POSITION TARGET TIME VECTOR B29 M
# CSTEER C FOR STEER LAW DP B2
# DLTARG TARGET TIME-IGNITION TIME DP B28 CS
# OUTPUT
# UT DESIRED THRUST DIRECTION VECT. B2 M/(CS.CS)
# VGTIG INITIAL VALUE OF VELOCITY
# TO BE GAINED (INERT. COORD.) VECTOR B7 M/CS
# DELVLVC VGTIG IN LOC. VERT. COORDS. B7 M/CS
# BDT V REQUIRED AT TIG -V REQUIRED AT (TIG-2SEC)
# -GDT FOR S40.13 VECT B7 M/CS
# RTIG CALC IN S40.1B (AIMPT) FOR S40.2,3 VECTOR B29M
# POSITION AT TIME OF IGNITION
# DEBRIS QTEMP1
# MPAC, QPRET
# PUSHLIST
BANK 14
SETLOC P40S1
BANK
## Page 758
COUNT* $$/S40.1
S40.1 STQ DLOAD
QTEMP
TIG
STORE TIGSAVE
DELVTEST BOFF
XDELVFLG
S40.1B
CALCTHET SETPD VLOAD
0
VTIG
STORE VINIT
VXV UNIT
RTIG
STOVL UT # UP IN UT
RTIG
STORE RINIT
VSQ PDDL
36D
DMP DDV
THETACON
DMP DMP
DELVSAB
WEIGHT/G
DDV
F
STOVL 14D
DELVSIN
DOT VXSC
UT
UT
VSL2 PUSH # (DELTAV.UP)UP SCALED AT 2(+7) P.D.L. 0
BVSU PDDL # DELTA VP SCALED AT 2(+7) P.D.L. 6
DELVSIN
14D
SIN PDVL
6D
VXV UNIT
UT
VXSC STADR
STOVL VGTIG # UNIT(VP X UP)SIN(THETAT/2) IN VGTIG.
UNIT PDDL # UNIT(DELTA VP) IN P.D.L. 6
14D
COS VXSC
VAD VXSC
VGTIG
36D
VSL2 VAD
STADR
## Page 759
STORE VGTIG # VG IGNITION SCALED AT 2(+7) M/CS
UNIT
STOVL UT # THRUST DIRECTION SCALED AT 2(+1)
VGTIG
PUSH CALL
GET.LVC # VGTIG IN LV COOR AT 2(+7) M/CS IN DELVLVC
GOTO
QTEMP
S40.1B DLOAD
TIG
STORE TDEC1
BDSU
TPASS4
STCALL DELLT4 # INTERCEPT TIME - TIG.
LEMPREC
VLOAD SETPD # LOAD STATE VECTOR AT TIG FOR INITVEL.
RATT
0
STORE RTIG
STORE RINIT
UNIT
STOVL UNIT/R/
VATT
STORE VTIG
STORE VINIT
DLOAD PDDL # NUMIT = 0
ZEROVECS
EPS1
BOFF DAD
NORMSW
SMALLEPS
EPS2 # EPSILON4 = 10 DEGREES OR 45 DEGREES.
SMALLEPS PUSH SXA,1
RTX1
SXA,2 CALL
RTX2
INITVEL
VLOAD PUSH
DELVEET3 # VGTIG = VR - VN.
STORE VGTIG
UNIT # UT = UNIT (VGTIG)
STODL UT
36D
STCALL VGDISP # CONVERT VGTIG (IN PUSHLIST) TO LOCAL
GET.LVC # VERTICAL COORDINATES.
GOTO
QTEMP
EPS1 2DEC* 2.777777778 E-2* # 10 DEGREES AT 1 REVOLUTION.
## Page 760
EPS2 2DEC* 9.722222222 E-2* # 35 DEGREES AT 1 REVOLUTION.
THETACON 2DEC .31830989 B-8
## Page 761
# SUBROUTINE NAME: S40.2,3 MOD. NO. 3 DATE: APRIL 4, 1967
# MODIFICATION BY: JONATHAN D. ADDELSTON (ADAMS ASSOCIATES)
# MOD. NO. 4: JULY 18, 1967: PETER ADLER (MIT/IL)
# MOD. NO. 5: OCTOBER 18, 1967: PETER ADLER (MIT/IL)
# ORIGINALLY BY: SAYDEAN ZELDIN (MIT INSTRUMENTATION LAB) AND RICHARD TALAYCO (SYSTEM DEVELOPMENT CORP)
# S40.2,3 COMPUTES "POINTVSM" WHICH IS THE HALF-UNIT DESIRED THRUST VECTOR IN STABLE-MEMBER COORDINATES FROM "UT"
# WHICH IS THE SAME VECTOR IN REFERENCE COORDINATES. IT DETERMINES THE CORRECT VALUES FOR "SCAXIS" USING THE +X
# AXIS FOR DPS, APS, AND RCS BURNS. THE "WINGS-LEVEL HEADS-UP" LM ORIENTATION IS THEN COMPUTED IN REFERENCE
# COORDINATES. THESE VECTORS ALSO DEFINE THE "PREFERRED IMU ORIENTATION". UPON COMPLETION OF THIS CALCULATION,
# THE "PREFERRED ATTITUDE COMPUTED" FLAG IS SET (PFRATFLG).
# CALLING SEQUENCE:
# L CALL INTERPRETIVE CALL.
# L +1 S40.2,3
# L +2 (RETURN) GIMBAL ANGLE VECTOR IN MPAC.
# SUBROUTINES CALLED: NONE.
# NORMAL RETURN: L +2 (SEE CALLING SEQUENCE ABOVE).
# ALARM/ABORT MODES: NONE.
# INPUT:
# 1. REFSMMAT MATRIX FROM REFERENCE TO STABLE-MEMBER COORDINATES SCALED AT 2.
# 2. UT HALF-UNIT DESIRED THRUST DIRECTION.
# 3. RTIG POSITION AT TIG IN REFERENCE COORDINATES.
# OUTPUT:
# 1. : XSCREF : WINGS-LEVEL HEADS-UP LM ORIENTATION
# : YSCREF : IN REFERENCE COORDINATES
# : ZSCREF : (PREFERRED IMU ORIENTATION).
# 2. POINTVSM DESIRED THRUST DIRECTION IN STABLE-MEMBER COORDINATES.
# 3. SCAXIS HALF-UNIT OF AXIS TO ALIGN IN STABLE-MEMBER COORDINATES.
# 4. PFRATFLG INTERPRETIVE FLAG. ON: PREFERRED ORIENTATION COMPUTED; OFF: NOT COMPUTED.
# DEBRIS: NONE.
## Page 762
COUNT* $$/S40.2
S40.2,3 VLOAD # UT: DESIRED THRUST DIRECTION (HALF-UNIT)
UT # (PUT INTO TOP OF PUSH-DOWN-LIST.)
MXV VSL1 # TRANSFORM THRUST DIRECTION TO STABLE-
REFSMMAT # MEMBER FROM REFERENCE COORDS (RESCALE).
STOVL POINTVSM # SAVE FOR "VECPOINT" ROUTINE (LEMMANU).
UNITX # SCAXIS SET TO +X, FOR P40 AND P42 AND
STOVL SCAXIS # FOR P41 IF RCS NOT -X,+Y,-Y,+Z,-Z.
UT # ASSUME +X BURN ALWAYS, EVEN FOR RCS.
PLUSX STORE XSCREF # XSCREF = UT (DESIRED THRUST DIRECTION.)
VXV UNIT # RTIG = POSITION AT TIME-OF-IGNITION.
RTIG # YSCREF = UNIT(UT X RTIG)
PDDL BHIZ
36D # TEST MAGNITUDE OF UT X RTIG
FIXY # IF SMALL, USE UT X VTIG AS YSC
STORY VLOAD STADR
STORE YSCREF
VXV VSL1 # COMPUTE (YSCREF X XSCREF), BUT FOR A
XSCREF # RIGHT HANDED SYSTEM, NEED (X CROSS Y).
VCOMP # ZSCREF = - (YSCREF X XSCREF)
STORE ZSCREF # = + (XSCREF X YSCREF)
SET RVQ
PFRATFLG
FIXY VLOAD VXV # IN THIS CASE,
XSCREF # YSCREF = UNIT(XSCREF X VTIG)
VTIG
UNIT PUSH
GOTO
STORY
## Page 763
# SUBROUTINE S40.8
# MODIFIED APRIL 3, 1968 BY PETER ADLER MIT/IL
# DESCRIPTION
# S40.8 UPDATES THE VELOCITY-TO-BE-GAINED VECTOR, VG, (AND FOR LAMBERT TARGETTED BURNS ALSO EXTRAPOLATES VG
# USING THE BDT VECTOR) COMPUTES THE TIME FOR ISSUING THE ENGINE OFF COMMAND, TGO, AND CALLS THE ROUTINE
# "FINDCDUW", WHICH GENERATES STEERING COMMANDS FOR THE DAP.
# CALLING SEQUENCE
# L-1 CALL
# L S40.8
# L+1 INTERPRETIVE RETURN
# ALARM
# IF VG . DELVREF IS NEGATIVE (VG AND DELVREF OVER 90 DEGREES APART), BYPASS TGO AND STEERING COMPUTATIONS
# AND SET ALARM 1407. RETURN TO CALLER NORMALLY.
# INPUT AND INITIALIZATION
# VGPREV REFERENCE 2(7) M/CS
# DELVREF REFERENCE 2(7) M/CS
# BDT REFERENCE 2(7) M/CS
# TDECAY TAIL-OFF TIME 2(28) CS
# XDELVFLG 1 = EXTERNAL DELTA-V; 0 = LAMBERT (AIMPOINT)
# STEERSW 1 = DO STEERING AND TGO COMPUTATIONS; 0 = VG UPDATE ONLY
# FIRSTFLG 1 = GONE TO LAMBERT AT LEAST ONCE; 0 = HAVEN'T GONE TO LAMBERT YET
# NOTE: VGTIG EQUALS VGPREV
# OUTPUT
# STEERSW SEE INPUT
# IMPULSW 1 = ENGINE OFF IN TGO CENTISECONDS; 0 = CONTINUE BURN
# TGO TIME TO CUT-OFF 2(28) CS
# SEE FINDCDUW FOR STEERING OUTPUTS.
# SUBROUTINE CALLED
# FINDCDUW
# DEBRIS
# MPACS, PUSHLIST
COUNT* $$/S40.8
## Page 764
S40.8 BOF # GENERATE VR IF NOT EXTERNAL DELTA-V BURN
XDELVFLG
RASTEER1
VLOAD VSU
VGPREV
DELVREF
VGAIN* STORE VG # VELOCITY TO BE GAINED SCALED AT (7) M/CS
MXV VSL1
REFSMMAT
STORE UNFC/2
BDTOK VLOAD ABVAL
VG
STORE VGDISP
TGDCALC SETPD VLOAD
0
VG
STOVL VGPREV
DELVREF
BOFF VCOMP
STEERSW
QPRET
UNIT
DOT PUSH
VG
BPL DDV
ALARMIT # DELV IS MORE THAN 90 DEGREES FROM VG.
VEX
DAD DMP
DPHALF
SR DDV
10D
36D
DMP DAD
-FOURDT
TDECAY
STORE TGO
DAD
PIPTIME
STODL TIG
TGO
DSU BPL
FOURSECS # 400 CS
FINDCDUW -2
SET CLRGO
IMPULSW
STEERSW
QPRET
ALARMIT EXIT
## Page 765
TC ALARM
OCT 01407
TC INTPRET
GOTO # SKIP TGO COMPUTATION BUT CALL FINDCDUW.
FINDCDUW -2 # FINDCDUW WILL EXIT TO UPDATEVG +3.
-FOURDT 2DEC -800 B-18 # -4 (200 CS.) B(-18)
FOURSECS 2DEC 400 # 400 CS SCALED AT 2(+28) CS
2VEXHUST = VEX
## Page 766
# NAME S40.13 - TIMEBURN
# FUNCTION (1) DETERMINE WHETHER A GIVEN COMBINATION OF VELOCITY TO
# BE GAINED AND ENGINE CHOICE RESULT IN A BURN TIME
# SUFFICIENT TO ALLOW STEERING AT THE VEHICLE DURING THE
# BURN
# (2) THE MAGNITUDE OF THE RESULTING BURN TIME -- IF IT
# IS SHORT -- AND THE ASSOCIATED TIME OF THE ENGINE OFF
# SIGNAL
# CALLING SEQUENCE VIA FINDVAC AS A NEW JOB
# INPUT VGTIG VELOCITY TO BE GAINED VECTOR (METERS/CS) AT +7
# WEIGHT/G MASS OF VEHICLE IN KGM AT +16
# F APS ENGINE THRUST IN M.NEWTONS AT +7
# AND ALSO FOR RCS ENGINE
# MDOT RATE OF DECREASE OF VEHICLE MASS DURING ENGINE
# BURN IN KILOGRAMS/CS AT +3. THIS SCALING MAY
# REQUIRE MODIFICATION FOR SATURN BURNS.
# ENG1FLAG SWITCH TO DECIDE WHETHER APS OR DPS ENGINE IS USED
# =0 DPS
# =1 APS
# OUTPUT IMPULSW ZERO FOR STEERING
# ONE FOR ATTITUDE HOLD
# NOTHROTL ZERO FOR THROTTLING
# ONE TO INHIBIT THROTTLING
# TGO TIME TO BURN IN CS
# THE QUANTITY M.NEWTON = 10000 NEWTONS WILL BE USED TO EXPRESS
# FORCE
EBANK= TGO
COUNT* $$/40.13
S40.13 TC INTPRET
SETPD CLEAR
00D
IMPULSW # ASSUME NO STEERING UNTIL FOUND OTHERWISE
VLOAD ABVAL
VGTIG # VELOCITY TO BE GAINED AT +7
PDDL DMP # 00D = MAG OF VGTIG AT +7
4SEC(17) # CORRECT VG FOR 4 SECS OF 2 JET ULLAGE
FRCS2
DDV SL1 # SCALE
WEIGHT/G
BDSU PUSH
BOFF SET
APSFLAG
S40.13D # FOR DPS ENGINE
NOTHROTL
DLOAD DDV # 00D = MAG OF VGTIG CORRECTED
K1VAL # M.NEWTONS-CS AT +24
WEIGHT/G
BDSU BMN
## Page 767
00D
S40.131 # TGO LESS THAN 100 CS
PDDL DMP # 02D = TEMP1 AT +7
MDOT
# MDOT REPRESENTS THE RATE OF DECREASE OF VEHICLE MASS DURING ENGINE
# BURN IN KILOGRAMS/CS. WHEN SATURN IS USED, THE SCALING MAY
# REQUIRE ADJUSTMENT
3.5SEC # 350 CS AT +14
BDSU PDDL
WEIGHT/G
F
DMP SR2 # SCALE
5SECS
DDV PUSH # 04D = TEMP2
BDSU BPL
02D
S40.13D
DLOAD BDDV
DMP DAD
5SECS
1SEC2D # 100 CS AT +14
GOTO
S40.132
S40.131 DLOAD DMP
WEIGHT/G
SR1 PUSH
DAD DDV
K2VAL # M.NEWTON CS AT +24
K3VAL # M.NEWTON CS AT +10
S40.132 SET EXIT
IMPULSW
S40.132* TC TPAGREE
CA MPAC
XCH L
CA ZERO
DXCH TGO
TCF S40.134
S40.13D DLOAD DMP # FOR DPS ENGINE
00D
WEIGHT/G
PUSH BON
APSFLAG
APSTGO
DDV CLEAR
S40.136
NOTHROTL
BOV PUSH
## Page 768
S40.130V
S40.137 DSU BPL
6SEC # 600.0 CS AT +14
S40.138
DAD GOTO
6SEC
S40.132
S40.133 EXIT
S40.134 TC PHASCHNG
OCT 00003
TC ENDOFJOB
S40.130V DLOAD SR4 # RECOMPUTE TGO IN TIME2 UNITS
DDV
S40.136_ # S40.136 SHIFTED LEFT 10
STORE TGO
EXIT
TCF S40.134 # REJOIN COMMON CODING FOR RESTART PROTECT
S40.138 DSU BPL
89SECS
STORETGO
SET
NOTHROTL
STORETGO DLOAD # LOAD TGO AT 2(14)
EXIT
TCF S40.132*
APSTGO DDV SL2
FAPS
GOTO
STORETGO +1
1SEC2D 2DEC 100.0 B-14 # 100.0 CS AT +14
3.5SEC 2DEC 350.0 B-13 # 350 CS AT +13
5SECS 2DEC 500.0 B-14 # 500.0 CS AT +14
6SEC 2DEC 600.0 B-14 # 600.0 CS AT +14
89SECS 2DEC 8900.0 B-14
# FUNCTION (1) GENERATES REQUIRED VELOCITY AND VELOCITY-TO-BE-GAINED
# VECTORS FOR USE DURING AIMPOINT MANEUVERS EVERY TWO
# COMPUTATION CYCLES (4 SECONDS).
# (2) UPDATES THE B VECTOR WHICH IS USED IN THE FINAL
# CALCULATION OF EXTRAPOLATING THE VELOCITY-TO-BE-GAINED
# THROUGH ONE 2-SECOND INTERVAL INTO THE FUTURE.
# CALLING SEQ VIA FINDVAC AS NEW JOB.
# INPUT RN - ACTIVE VEHICLE RADIUS VECTOR IN METERS AT +29.
# VN - ACTIVE VEHICLE VELOCITY VECTOR IN METERS/CS AT +7
## Page 769
# VRPREV - LAST COMPUTED VELOCITY REQUIRED VECTOR IN
# METERS/CS AT +7.
# TIG - TIME OF IGNITION IN CS AT +28.
# DLTARG - COMPUTATION CYCLE INTERVAL = 200 CS AT +28.
# PIPTIME - TIME OF RN AND VN IN CS AT +28.
# GDT/2 - HALF OF VELOCITY GAINED IN DELTA T TIME DUE TO
# ACCERERATION OF GRAVITY IN METERS/CS AT +7.
# DELVREF - CHANGE IN VELOCITY DURING LAST 2 SEC IN
# METERS/CS AT +7.
# OUTPUT VGPREV - VELOCITY TO BE GAINED VECTOR IN METERS/CS AT +7.
# VGDISP - MAG OF VGPREV FOR DISPLAY PURPOSES.
# VRPREV - VELOCITY REQUIRED VECTOR IN METERS/CS AT +7.
# BDT - B VECTOR IN METERS/CS AT +7.
# SUBROUTINES USED - INITVEL
EBANK= VGPREV
COUNT* $$/S40.9
S40.9 TC INTPRET
SETPD
00D
SET DLOAD
AVFLAG # SET AVFLAG FOR LEM ACTIVE
HI6ZEROS
PDDL
EPS1
BOFF DAD # EPSILON4 = 10 OR 45 DEGREES.
NORMSW
EPSSMALL
EPS2
EPSSMALL PUSH CALL
HAVEGUES
ENDS40.9 EXIT
TC PHASCHNG
OCT 2
TCF ENDOFJOB
RASTEER1 VLOAD ABVAL
RN
LXC,2 SL*
RTX2
0,2
STOVL RMAG
RTARG
VSU RTB
RN
NORMUNX1
STODL IC
36D # C(36D) = ABVAL(C)
XAD,2 SL*
X1
## Page 770
0,2
STORE 30D
NORM DMP
X2
RMAG
NORM XAD,2
X1
X1
SXA,2
MUSCALE
STODL R1C # 2(+58 -X)
30D
SR1 PDDL
RMAG
SR1 PDDL
RTMAG
SR1 DAD
DAD STADR
STORE SS # SS = (R1 + R2 + C)/2
DSU DMP
30D
MU/A
BDSU
MUASTEER
PDDL DSU
SS
RMAG
NORM SR1
X1
DDV DMP
R1C
XSU,2 SL*
X1
1,2
LXA,2
MUSCALE
SQRT SIGN
GEOMSGN
STORE 32D # + OR - A
DLOAD DMP
SS
MU/A
BDSU
MUASTEER
PDDL DSU
SS
RTMAG
NORM SR1
X1
DDV DMP
## Page 771
R1C
XSU,2 SL*
X1
1,2
SQRT PDDL # -B (NO SIGN)
SS
DSU DDV
30D
SS
SQRT PUSH
SR1 ASIN
DMP PDDL
2PI+3
PDDL DDV
30D
SS
BOV
+1
SQRT DMP
SR3 BDSU
SIGN PDDL
GEOMSGN
2PI+3
SR2 DSU
DMP PDDL
SS
SS
SR3 SQRT
DMP
PDDL SL3
MUASTEER
SQRT BDDV
DSU DAD
TPASS4
PIPTIME
STODL 30D
SIGN
30D # B WITH SIGN
STORE 30D
BON VLOAD
NORMSW
180MESS
IC
VSU UNIT
UNIT/R/
VXSC PDVL
30D
IC
VAD UNIT
UNIT/R/
## Page 772
GETVRVG1 VXSC VAD
32D
GETVRVG2 LXC,2 VSR*
RTX2
0 -1,2
STORE VIPRIME
GOTO
ASTREND -2
180MESS VLOAD DOT
IC
UNIT/R/
BMN VLOAD
NEGPROD
IC
VSR1 PDVL
UNIT/R/
VSR1 VAD
UNIT
PUSH VCOMP # FOR A
VXV SIGN
UN
GEOMSGN
UNIT VXSC
30D
PDVL # UNIT(IC-IR) +-B
GOTO
GETVRVG1
NEGPROD VLOAD VSR1
UNIT/R/
PDVL VSR1
IC
VSU UNIT
PUSH
VXV SIGN
UN # FOR B
GEOMSGN
UNIT VXSC
32D
PDVL
VXSC VAD
30D
GOTO
GETVRVG2
VSU
VN1
ASTREND STORE DELVEET3
FIRSTTME SLOAD BZE
RTX2
GETGOBL
VLOAD GOTO # NO OBLATENESS COMP IF IN MOON SPHERE
## Page 773
DELVEET3
NOGOBL
GETGOBL VLOAD UNIT # CALCULATE OBLATENESS TERM.
RN
DLOAD DSU
PIPTIME # 2
GOBLTIME # G = -(MU/R )(UNITGOBL)(T-TIG)
DMP DDV # OBL
EARTHMU
34D # 34D = /RN/ (2) FROM UNIT OPERATION.
VXSC VAD
UNITGOBL
DELVEET3 # OUTPUT FROM INITVEL VG = VR - VN
NOGOBL STORE DELVEET3 # VG = VR + GOBL - VN
GOTO
VGAIN*
2PI+3 2DEC 3.141592653 B-2
## Page 774
# TRIMGIMB (FORMERLY S40.6)
# MOD 0 24 FEB 67 PETER ADLER
# FUNCTION:
# TRIMS DPS ENGINE TO MINIMIZE THRUST/CG OFFSET. ENGINE IS GIMBALLED TO FULL + PITCH AND + ROLL (TO LOCK)
# FOR REFERENCE AND IS THEN BROUGHT BACK TO TRIM POSITION BY RUNNING FOR THE PROPER TIMES (TO BE
# SPECIFIED BY GAEC) IN - PITCH AND - ROLL.
# CALLING SEQUENCE:
# VIA WAITLIST FROM R03
# INPUT:
# PITTIME TIME TO RUN FROM FULL + PITCH TO TRIM (CS)
# ROLLTIME TIME TO RUN FROM FULL + ROLL TO TRIM (CS)
# SUBROUTINES USED:
# WAITLIST, FIXDELAY, VARDELAY, FLAGUP, FLAGDOWN, NOVAC
COUNT* $$/S40.6
EBANK= ROLLTIME # OCTAL MASKS: PRIO5=05000 EBANK5=02400
TRIMGIMB TC DOWNFLAG # GMBDRVSW FLAG IS SET WHEN EITHER ROLL OR
ADRES GMBDRVSW # PITCH IS COMPLETED, WHICHEVER IS FIRST.
CS PRIO5 # TURN OFF - PITCH, - ROLL, IF ON.
EXTEND
WAND CHAN12
CAF EBANK5 # TURN ON + PITCH, + ROLL.
EXTEND
WOR CHAN12
TC FIXDELAY # WAIT ONE MINUTE TO MAKE SURE ENGINE IS
DEC 6000 # AT FULL + PITCH AND FULL + ROLL
CS EBANK5 # TURN OFF + PITCH, + ROLL.
EXTEND
WAND CHAN12
CAF PRIO5 # TURN ON - PITCH, - ROLL.
EXTEND
WOR CHAN12
CAE PITTIME # GET TIME TO SHUT OFF - PITCH AND SET UP
TC TWIDDLE # TWIDDLE-TASK TO TURN IT OFF THEN
ADRES PITCHOFF
CAE ROLLTIME # GET TIME TO SHUT OFF - ROLL AND GO AWAY
TC VARDELAY # UNTIL THEN
CS BIT12
EXTEND
WAND CHAN12 # SHUT OFF ROLL
ROLLOVER CA FLAGWRD6 # IF HERE INLINE (ROLL DONE) IS PITCH DONE
MASK GMBDRBIT # IF HERE FROM PITCHOFF, IS ROLL DONE?
EXTEND
BZF PITCHOFF +4 # NO. SET FLAG, ROLL OR PITCH DONE.
CAF PRIO10 # RETURN TO R03
TC NOVAC
EBANK= WHOCARES
## Page 775
2CADR TRIMDONE
TC TASKOVER
PITCHOFF CS BIT10
EXTEND
WAND CHAN12 # SHUT OFF PITCH
TCF ROLLOVER # SEE IF ROLL HAS FINISHED ALSO.
TC UPFLAG # ROLL DONE; OR PITCH DONE; BUT NOT BOTH.
ADRES GMBDRVSW
TC TASKOVER
## Page 776
# SUBROUTINE NAME: S41.1 MOD. NO. 0 DATE: FEBRUARY 28, 1967
# MOD. NO. 1 DATE: JANUARY 23, 1968: BY PETER ADLER (MIT/IL)
# AUTHOR: JONATHAN D. ADDELSTON (ADAMS ASSOCIATES)
# S41.1 PERFORMS THE COORDINATE SYSTEM TRANFORMATION FROM THE REFERENCE FRAME TO THE BODY OF THE LM.
# SPECIFICALLY, IT IS USED TO TRANSFORM A VELOCITY (SCALED AT 2(+7) METERS/CENTISECOND) FROM REFERENCE TO LM AXIS
# COORDINATES. FIRST THE VECTOR IS TRANSFORMED TO THE STABLE MEMBER COORDINATES BY THE MATRIX REFSMMAT. THIS
# LEAVES THE VECTOR IN MPAC, SCALED AT 2(+8) METERS/CENTISECOND. THEN
# THE SUBROUTINE CDUTRIG IS CALLED TO SET UP THE DOUBLE-PRECISION CDU VECTOR ALONG WITH ITS SINES AND COSINES.
# THE VECTOR IS THEN TRANSFORMED FROM STABLE MEMBER COORDINATES TO SPACECRAFT (OR LM) COORDINATES BY THE
# SUBROUTINE *SMNB*. FINALLY( THE VECTOR IS RESCALED TO 2(+7) METERS/CENTISECOND, AND CONTROL IS RETURNED TO THE
# CALLER WITH C(MPAC) = VELOCITY(LM).
# CALLING SEQUENCE:
# L VLOAD CALL
# L +1 VELOCITY(REF) SCALED AT 2(+7) M/CS IN REFERENCE COORDS.
# L +2 S41.1
# L +3 STORE VELOCITY(LM) SCALED AT 2(+7) M/CS IN LM BODY AXIS SYS.
# SUBROUTINES CALLED:
# 1. CDUTRIG,
# WHICH CALLS CDULOGIC.
# 2. *SMNB*
# NORMAL RETURN: L +3 (SEE CALLING SEQUENCE, ABOVE.)
# ALARM/ABORT MODES: NONE.
# RESTART PROTECTION: NONE.
## Page 777
# INPUT:
# 1. REFSMMAT.
# 2. CDUX, CDUY, CDUZ.
# 3. VELOCITY (REF) IN MPAC.
# OUTPUT:
# 1. CDUSPOT: DOUBLE PRECISION CDU VECTOR, ORDERED Y,Z,X.
# 2. SINCDU: HALF SINES OF CDUSPOT COMPONENTS.
# 3. COSCDU: HALF COSINES OF CDUSPOT COMPONENTS.
# 4. MPAC: VELOCITY(LM) (SCALED AT 2(+7) METERS/CENTISECOND)
# DEBRIS: NONE.
# CHECKOUT STATUS: CODED.
COUNT* $$/S41.1
S41.1 MXV VSL1 # CONVERT VECTOR IN MPAC FROM REF AT 2(+7)
REFSMMAT # TO SM AND RESCALE DUE TO HALFUNIT MATRIX
GOTO # CONVERT TO BODY AT 2(+7) USING PRESENT
CDU*SMNB # CDU ANGLES. CDU*SMNB WILL RETURN
# VIA RVQ TO THE CALLER OF S41.1
