Apollo-11/Comanche055/SERVICER207.agc

# Copyright:    Public domain.
# Filename:     SERVICER207.agc
# Purpose:      Part of the source code for Comanche, build 055. It
#               is part of the source code for the Command Module's
#               (CM) Apollo Guidance Computer (AGC), Apollo 11.
# Assembler:    yaYUL
# Reference:    pp. 819-836
# Contact:      Ron Burkey <info@sandroid.org>
# Website:      http://www.ibiblio.org/apollo.
# Mod history:  2009-05-12 RSB	Adapted from Colossus249 file of the same
#				name and Comanche 055 page images.
#
# The contents of the "Comanche055" files, in general, are transcribed
# from scanned documents.
#
#       Assemble revision 055 of AGC program Comanche by NASA
#       2021113-051.  April 1, 1969.
#
#       This AGC program shall also be referred to as Colossus 2A
#
#       Prepared by
#                       Massachusetts Institute of Technology
#                       75 Cambridge Parkway
#                       Cambridge, Massachusetts
#
#       under NASA contract NAS 9-4065.
#
# Refer directly to the online document mentioned above for further
# information.  Please report any errors to info@sandroid.org.

# Page 819
# SERVICER207

# PROGRAM NAME - PREREAD, READACCS, SERVICER, AVERAGE G.


# MOD NO. 00	BY M.HAMILTON	DEC.12, 1966


# FUNCTIONAL DESCRIPTION

# THE ROUTINES DESCRIBED BELOW ARE USED TO CALCULATE VALUES OF RN, VN, AND GDT/2 DURING ACCELERATED FLIGHT.
# THE SEVERAL ROUTINES COMPRISE A PACKAGE AND ARE NOT MEANT TO BE USED AS SEPARATE SUBROUTINES.

# GENERAL REFERENCES TO SERVICER OR AVERAGE G ARE UNDERSTOOD TO REFER TO THE ENTIRE SET OF ROUTINES INCLUDING
# READACCS, SERVICER, AVERAGE G, INTEREAD, SMOOTHER, AND ANY ADDITIONAL ROUTINES ATTACHED AT AVGEXIT (SEE BELOW).

# PROGRAMS INITIATING SERVICER ARE REQUIRED TO MAKE A WAITLIST CALL FOR PREREAD (OR, IF LIFTOFF, FOR BIBIBIAS)
# AT 2 SECONDS BEFORE THE FIRST AVERAGE G UPDATE IN ORDER TO INITIALIZE THE SEQUENCE, WHICH WILL RECUR EVERY
# 2 SECONDS FROM THAT TIME ON AS LONG AS AVEGFLAG REMAINS SET.

# THE USE OF ERASABLE AVGEXIT ALLOWS VARIOUS ROUTINES TO BE PERFORMED AS PART OF THE NORMAL CYCLE (SEE
# EXPLANATION OF AVGEXIT BELOW).

# DESCRIPTIONS OF INDIVIDUAL ROUTINES FOLLOW.


#	PREREAD

#		PREVIOUSLY EXTRAPOLATED VALUES COPIED FROM RN1, VN1, AND PIPTIME1 INTO RN, VN, AND PIPTIME.
#		LASTBIAS JOB SCHEDULED.
#		PIPS READ AND CLEARED VIA PIPASR SUBROUTINE.
#		AVERAGE G FLAG SET ON.
#		DRIFT FLAG SET OFF.
#		V37 FLAG SET ON.
#		INITIALIZATION OF	1) THRUST MONITOR (DVMON) - DVCNTR SET TO ONE.
#					2) TOTAL ACCUMULATED DELV VALUE (DVTOTAL) - SET TO ZERO.
#					3) AXIS VECTOR (AXIS) - SET TO (.5,0,0).
#		NORMLIZE JOB SCHEDULED.
#		READACCS TASH CALLED IN 2 SECONDS.


#	NORMLIZE
#
#		GDT/2 INITIALIZED VIA CALCGRAV SUBROUTINE.


#	READACCS

#		IF ONMON FLAG SET QUIKREAD ROUTINE IS PERFORMED BEFORE PIPASR ZEROS THE PIPA REGISTERS, AND THE 1/2 SEC
#		ONMONITOR LOOP IS INITIATED TO PROVIDE DOWNLINK INFORMATION DURING ENTRY.
#		PIPS READ AND CLEARED BY PIPASR SUBROUTINE.
#		IF CM/DSTBY IS ON, ENTRY VARIABLES INITIALIZED AND SETJTAG TASK CALLED.
# Page 820
# SERVICER207

#		IF AVERAGEG FLAG ON	READACCS CALLED TO RECYCLE IN 2 SECONDS.
#		IF AVERAGEG FLAG OFF	AVERAGE G EXIT (AVGEXIT) SET TO 2CADR AVGEND FOR FINAL PASS.
#		SERVICER JOB SCHEDULED.


#		TEST CONNECTOR OUTBIT TURNED ON.


# ONMNITOR

#		A SEQUENCE OF THREE PASSES THROUGH QUICREAD FOLLOWING A CALL TO READACCS WITH ONMONFLG SET AT 1/2
#		SEC INTERVALS.  INTERVALS ARE COUNTED OUT BY PIPCTR, INITIALISED AT 3 BY READACCS

#	QUIKREAD

#	      READS CURRENT PIPS INTO X,Y,ZPIPBUF.  READS OLD X,Y,ZPIPBUF INTO X,Y,ZOLDBUF.  VALUES ARE SENT TO
#		DOWNLIST DURING ENTRY.
#	SERVICER
#		DELV VALUES CHECKED TO DETECT RUNAWAY PIP -
#			IF BAD PIP	1) ALARM SENT.
#					2) COMPENSATION, DVTOTAL ACCUMULATION, AND DVMON BYPASSED.  CONTROL
#					   TRANSFERRED TO AVERAGE G.
#		PIPS COMPENSATED VIA 1/PIPA SUBROUTINE.
#		DVTOTAL INCREMENTED BY ABSOLUTE VALUE OF DELV.
#		THRUST MONITOR (DVMON) PERFORMED UNLESS IDLE FLAG IS ON.
#		CONTROL TRANSFERRED TO AVERAGE Q.


#		DVMON

#			THRESHOLD VALUD (PLACED IN DVTHRUSH BY USER) CHECKED AGAINST ABSOLUTE VALUE OF DELV TO CHECK
#			THRUST LEVEL.
#				IF THRUST	1) ULLAGE OFF ROUTINE PERFORMED.
#						2) STEERING FLAG TURNED ON AT FIRST DETECTION OF THRUST.
#						3) CONTROL TRANSFERRED TO AVERAGE G.
#				IF NO THRUST	1) ON FIRST PASS THROUGH MONITOR, CONTROL TRANSFERRED TO AVERAGE G.
#						2) ON SUBSEQUENT PASSES, CONTROL TRANSFERRED TO ENGINE FAIL ROUTINE IF THRUST
#						   HAS FAILED FOR 3 CONSECUTIVE PASSES.


#		ENGINE FAIL

#			ENGFAIL1 TASK CALLED IN 2.5 SECONDS.  THIS WILL RETURN CONTROL TO TIG-5 SO THAT THE IGNITION
#				SEQUENCE MAY BE REPEATED.
#			ENGINOF3 PERFORMED.
#			DAP SET UP FOR RCS.


#	AVERAGE G
# Page 821
#	RN1, VN1, GDT1/2 CALCULATED VIA CALCRVG ROUTINE BY UPDATING RN, VN WITH DELV AND AN AVERAGED VALUE
#	OF GDT/2.
#	RN1, VN1, GDT1/2, PIPTIME1 COPIED INTO RN, VN, GDT/2, PIPTIME FOR RESTART PROTECTION.
#	CONTROL TRANSFERRED TO ADDRESS SPECIFIED BY USER (OR BY READACCS FOR LAST PASS) IN AVGEXIT.
#	LAST PASS (AVGEND)	1) FREE FALL GYRO COMPENSATION SET UP.
#				2) DRIFT FLAG TURNED ON.
#				3) STATE VECTOR TRANSFERRED VIA AVETOMID ROUTINE.
#				4) ONMONITOR FLAG RESET.
#				5) V37 FLAG RESET.
#				6) TEST CONNECTOR OUTBIT RESET.
#				7) CONTROL TRANSFERRED TO CANV37 TO CONTINUE MM CHANGE ROUTINE (R00).


# CALLING SEQUENCE

#	PREREAD ENTERED DIRECTLY FROM TIG-30 VIA POSTJUMP.
#	READACCS CALLED AS WAITLIST TASK.


# SUBROUTINES CALLED

# 	UTILITY ROUTINES - PHASCHNG FLAGUP FLAGDOWN NOVAC FINDVAC WAITLIST ALARM NEWPHASE 2PHSCHNG

#	OTHER - PIPASR 1/PIPA CALCGRAV CALCRVG AVETOMID


# NORMAL EXIT MODES

#	ENDOFJOB	TASKOVER	CANV37

#	AVGEXIT -	THIS IS A DOUBLE PRECISION ERASABLE LOCATION BY WHICH CONTROL IS TRANSFERRED AT THE END
#			OF EACH CYCLE OF AVERAGE G.
#			THE 2CADR OF A ROUTINE TO BE PERFORMED AT THAT TIME (E.G., STEERING EQUATIONS TO BE PERFORMED
#			AT 2 SECOND INTERVALS) MAY BE SET BY THE USER INTO AVGEXIT.
#			ALL SUCH ROUTINES SHOULD RETURN TO SERVEXIT, WHICH IS THE NORMAL EXIT FROM AVERAGE G.

#	SERVEXIT -	DOES A PHASE CHANGE FOR RESTART PROTECTION AND GOES TO ENDOFJOB.
#			THE 2CADR OF SERVEXIT IS SET INTO AVGEXIT BY THE USER IF NO OTHER ROUTINE (SEE ABOVE).
#
#	AVGEND -	LAST PASS OF AVERAGE G EXITS HERE, BYPASSING SPECIAL ROUTINE (SEE ABOVE UNDER READACCS).
#			FINAL EXIT IS TO CANV37.				F AVERAGE G).


# OUTPUT

#	DVTOTAL(2)  PIPTIME(2)  XPIPBUF(2)  YPIPBUF(2)  ZPIPBUF(2)
#	RN(6)		REFERENCE COORD.   SCALED AT 2(+29) M/CS
#	VN(6)		REFERENCE COORD.   SCALED AT 2(+7) M/CS
#	GDT/2(6)	REFERENCE COORD.   SCALED AT 2(+7) M/CS
#	DELV(6)		STABLE MEMB. COORD.SCALED AT 2(+14)*5.85*10(-4)M/CS (KPIP1 USED TO GET DV/2 AT 2(+7))
# Page 822
#	DELVREF(6)	REFERENCE COORD.   SCALED AT 2(+7) M/CS

# INITIALIZATION

#		ONMONITOR FLAG SET BY ENTRY TO SHOW PIPBUF VALUES REQUIRED.
#		IDLE FLAG ON IF DVMON TO BE BYPASSED.
#		DVTHRUSH SET TO APPROPRIATE VALUE FOR DVMON.
#		AVGEXIT SET TO 2CADR OF ROUTINE, IF ANY, TO BE PERFORMED AFTER EACH CYCLE OF AVERAGE G.  IF NO ROUTINE
#			TO BE DONE, AVGEXIT SET TO SERVEXIT.
#		VALUES NEEDED
#			REFSMMAT
#			UNITW - FULL UNIT VECTOR, IN REFERENCE COORD., OF EARTH S ROTATIONAL VECTOR
#			RN1, VN1, PIPTIME1 - IN REFERENCE COORD., CONSISTENT WITH TIME OF EXECUTION OF PREREAD


# DEBRIS

#	CENTRALS	A, L, Q
#	OTHER		INTERNAL -  DVCNTR(1)  PIPAGE(1)  PIPCTR(1)  AVGEXIT(2)
#			EXTERNAL -  ITEMP1(1)  ITEMP2(1)  RUPTREG1(1)  TEMX(1)  TEMY(1)  TEMZ(1)
#			USEFUL DEBRIS
#				RN1(6)  VN1(6)  GDT1/2  PIPTIME1(2)
#					THESE LOCATIONS USED AS BUFFER STORAGE FOR NEWLY CALCULATED VALUES OF RN, VN, GDT/2,
#					AND PIPTIME DURING PERFORMANCE OF SERVICER ROUTINES.
#				UNITR - HALF UNIT VECTOR OF RN, REFERENCE COORD.
#				RMAG SCALED AT 2(+58) IN 36D.
#				RMAGSQ SCALED AT 2(+58) IN 34D.
#				(RE/RMAG)SQ IN 32D.


		BANK	27
		SETLOC	SERVICES
		BANK

		EBANK=	DVCNTR
# ********************* PREREAD ***************************************
#

		COUNT	37/SERV

PREREAD		CAF	PRIO21		# CALLER MUST PROTECT PREREAD
		TC	NOVAC
		EBANK=	NBDX
		2CADR	LASTBIAS	# DO LAST GYRO COMPENSATION IN FREE FALL

					# CALL-TO AND LASTBIAS ITSELF ARE NOT
					#	PROTECTED. REREADAC SETS 1/PIPADT
					#	TO 2.0 SECS IN CASE LASTBIAS LOST.
					#	(REDUNDANT IF LASTBIAS IS AOK)
# Page 823
REDO5.31	TC	PREREAD1

		CAF	PRIO32
		TC	FINDVAC		# SET UP NORMLIZE JOB REQUIRED PRIOR TO
		EBANK=	DVCNTR		# FIRST AVERAGE G PASS
		2CADR	NORMLIZE

		CAF	2SECS
		TC	WAITLIST
		EBANK=	AOG
		2CADR	READACCS

		CS	TWO
		TC	NEWPHASE
		OCT	5

		TCF	TASKOVER

PREREAD1	EXTEND
		QXCH	RUPTREG1

		TC	PIPASR		# CLEAR + READ PIPS LAST TIME IN FREE FALL

		CAF	ONE		# SET UP PIPAGE FOR REREADAC IN CASE A
		TS	PIPAGE		# 	RESTART OCCURS BEFORE READACCS

		CS	FLAGWRD1	# SET AVEG FLAG
		MASK	BIT1
		ADS	FLAGWRD1

		CA	POSMAX
		MASK	FLAGWRD2
		TS	FLAGWRD2	# KNOCK DOWN DRIFT FLAG

		CS	FLAGWRD7	# SET V37 FLAG
		MASK	BIT6
		ADS	FLAGWRD7

		CAF	ZERO
		TS	DVTOTAL		# CLEAR DVTOTAL
		TS	DVTOTAL +1

		TC	RUPTREG1

# Page 824
# ********************* READACCS ***************************************
		EBANK=	AOG
READACCS	TC	PIPASR

PIPSDONE	CAF	FIVE
		TS	L
		COM
		DXCH	-PHASE5

REDO5.5		CAF	ONE		# SHOW PIPS HAVE BEEN READ
		TS	PIPAGE

		CA	TWO		# SET PIPCTR FOR ONMINTOR
		TS	PIPCTR		# AFTER ABOVE PHASCHNG

		CS	CM/FLAGS
		MASK	BIT2		# CM/DSTBY
		CCS	A
		TC	CHEKAVEG

		CS	PIPTIME1 +1
		TS	TBASE6		# FOR RESTARTS
		EXTEND			# CONTINUE FOR ENTRY DAP
		DCA	AOG
		DXCH	AOG/PIP
		CA	AMG
		XCH	AMG/PIP
		EXTEND
		DCA	ROLL/180
		DXCH	ROLL/PIP
		CA	BETA/180
		XCH	BETA/PIP
		CA	CM/FLAGS
		MASK	BIT12		# CM/DAPARM 93D BIT12
		EXTEND			# DURING ENTRY, WHEN RCS DAP IS INACTIVE,
		BZF	NOSAVPIP	# SAVE PIPAS EACH 0.5 SEC FOR TM.

		CA	0.5SEC
		TC	WAITLIST
		EBANK=	XPIPBUF
		2CADR	QUIKREAD

					# NO NEED TO RESTART PROTECT THIS.
		CA	DELVX		# SAVE PIPAS AS READ (BUT NOT COMPENSATED)
		XCH	XPIPBUF
		TS	XOLDBUF

		CA	DELVY
		XCH	YPIPBUF
		TS	YOLDBUF
# Page 825
		CA	DELVZ
		XCH	ZPIPBUF
		TS	ZOLDBUF

NOSAVPIP	CA	FIVE
		TS	CM/GYMDT

		CA	JTAGTIME	# ACTIVATE CM/RCS AFTER PIPUP TO GO
					# IN JTAGTIME +5 CS.
		TC	WAITLIST
		EBANK=	AOG
		2CADR	SETJTAG

		CS	THREE		# 1.3SPOT FOR SETJTAG
		TC	NEWPHASE
		OCT	1

		CAF	OCT37
		TS	L
		COM
		DXCH	-PHASE5

CHEKAVEG	CS	FLAGWRD1
		MASK	BIT1
		CCS	A		# IF AVEG FLAG DOWN SET FINAL EXIT AVEG
		TC	AVEGOUT

		CAF	2SECS
		TC	WAITLIST
		EBANK=	AOG
		2CADR	READACCS

MAKESERV	CAF	PRIO20		# ESTABLISH SERVICER ROUTINE
		TC	FINDVAC
		EBANK=	DVCNTR
		2CADR	SERVICER

		CS	FOUR		# RESTART SERVICER AND READACCS
		TC	NEWPHASE
		OCT	5

		CAF	BIT9
		EXTEND
		WOR	DSALMOUT	# TURN TEST CONNECTOR OUTBIT ON

		TCF	TASKOVER	# END PREVIOUS READACCS WAITLIST TASK

# Page 826
AVEGOUT		EXTEND
		DCA	AVOUTCAD
		DXCH	AVGEXIT
		TCF	MAKESERV

		EBANK=	DVCNTR
AVOUTCAD	2CADR	AVGEND

# Page 827
# ROUTINE NAME:	ONMNITOR
# MOD 04 BY BAIRNSFATHER 30 APR 1968	REDO ONMNITOR TO SAVE PIPS EACH 0.5 SEC FOR TM,ENTRY.
# MOD 03 BY FISHER DECEMBER 1967
# MOD 02 BY RYE SEPT 1967
# MOD 01 BY KOSMALA 23 MAR 1967
# MOD 00 BY KOSMALA 27 FEB 1967

# FUNCTIONAL DESCRIPTION

#	THE PURPOSE OF ONMONITOR IS TO PROVIDE 1/2 SEC.READING OF PIPAS FOR DOWNLIST DURING ENTRY.
#	X,Y,ZPIPBUF CONTAIN PRESET VALUES X,Y,ZOLDBUF CONTAIN VALUES FROM PREVIOUS READING.

# CALLING SEQUENCE

#	CALL AS WAITLIST TASK. TERMINATES ITSELF IN TASKOVER

# INITIALISATION

#	PIPCTR = 2 (FOR DT = 0.5 SEC)
#	X,Y,ZPIPBUF SET TO PREVIOUS PIPAX,Y,Z

# OUTPUT

#	X,Y,ZPIPBUF, X,Y,ZOLDBUF
# DEBRIS

#	X,Y,ZPIPBUF CONTAIN LAST PIPAX,Y,Z VALUES
#		X,Y,ZOLDBUF CONTAIN LAST-BUT-ONE PIPAX,Y,Z VALUES
#	RUPTREG1
#	PIPCTR

ONMNITOR	TS	PIPCTR

		TC	FIXDELAY	# WAIT
0.5SEC		DEC	50

QUIKREAD	CAF	TWO
		TS	RUPTREG1
		INDEX	A
		CA	PIPAX		# SAVE ACTUAL PIPAS FOR TM.
		INDEX	RUPTREG1
		XCH	XPIPBUF		# UPDATE X,Y,ZPIPBUF
		INDEX	RUPTREG1
		TS	XOLDBUF		# AND X,Y,ZOLDBUF
CHKCTR		CCS	RUPTREG1
		TCF	QUIKREAD +1	# LOOP AGAIN
		CCS	PIPCTR
		TCF	ONMNITOR
		TC	TASKOVER

# Page 828
# ********************* SERVICER ***************************************
#

		EBANK=	DVCNTR

SERVICER	CAF	TWO
		INHINT
PIPCHECK	TS	RUPTREG1

		DOUBLE
		INDEX	A
		CCS	DELVX
		TC	+2
		TC	PIPLOOP

		AD	-MAXDELV	# DO PIPA-SATURATION TEST BEFORE
		EXTEND
		BZMF	PIPLOOP		# COMPENSATION.

		TC	ALARM
		OCT	00205		# SATURATED-PIPA ALARM   ***CHANGE LATER
		TC	AVERAGEG

PIPLOOP		CCS	RUPTREG1
		TCF	PIPCHECK

		TC	PHASCHNG	# RESTART REREADAC + SERVICER
		OCT	16035
		OCT	20000
		EBANK=	DVCNTR
		2CADR	DVTOTUP

		TC	BANKCALL	# PIPA COMPENSATION CALL
		CADR	1/PIPA

DVTOTUP		TC	INTPRET
		VLOAD	ABVAL		# GET ABS VALUE OF DELV
			DELV
		DMP	EXIT
			KPIP1		# SCALE AT 2(+7)

		EXTEND
		DCA	MPAC
		DAS	DVTOTAL		# ACCUMULATE DVTOTAL
AVERAGEG	TC	PHASCHNG
		OCT	10035

		TC	INTPRET
		CALL
# Page 829
			CALCRVG
		EXIT

		TC	PHASCHNG
		OCT	10035

		CAF	OCT31		# COPY RN1,VN1,GOT102,GOBL1/2,PIPTIME1
		TC	GENTRAN		# INTO RN ,VN ,GDT/12 ,GOBL/2 ,PIPTIME
		ADRES	RN1
		ADRES	RN
		RELINT			# GENTRAN DOES AN INHINT
		TC	PHASCHNG
		OCT	10035

		EXTEND
		DCA	AVGEXIT
		DXCH	Z		# AVERAGEG EXIT

AVGEND		CA	PIPTIME +1	# FINAL AVERAGE G EXIT
		TS	OLDBT1		# SET UP FREE FALL GYRO COMPENSATION

		TC	UPFLAG		# SET DRIFTFLG
		ADRES	DRIFTFLG	# BIT 15 FLAG 2
		TC	2PHSCHNG
		OCT	5		# GROUP 5 OFF
		OCT	05022		# GROUP 2 ON FOR AVETOMID
		OCT	20000

		TC	INTPRET
		CALL
			AVETOMID	# CONVERT STATE VECTOR TO REFERENCE SCALE.
		EXIT

		CAF	ZERO		# ZERO MARK COUNTERS.
		TS	VHFCNT
		TS	TRKMKCNT

		TC	BANKCALL
		CADR	PIPFREE

		CS	BIT9
		TS	MRKBUF2		# INVALIDATE MARK BUFFER
		EXTEND
		WAND	DSALMOUT

		TC	DOWNFLAG
		ADRES	CM/DSTBY

		TC	DOWNFLAG
		ADRES	V37FLAG

# Page 830
		CAF	BIT7		# RESTORE GROUP 1 + 2 IF P20 IS RUNNING.
		MASK	FLAGWRD0
		EXTEND
		BZF	+4

		TC	2PHSCHNG
		OCT	111		# 1.11SPOT
		OCT	132		# 2.13SPOT

		TC	POSTJUMP
		CADR	CANV37

SERVEXIT	TC	PHASCHNG
		OCT	00035		# A, 5.3 = REREADAC (ONLY)

		TCF	ENDOFJOB

DVTHRUSH	EQUALS	ELEVEN		# 15 PERCENT OF 2SEC PIPA ACCUMULATION,
					#	FOR 503-FULL CSM/LEM....DELV SC.AT
					#	5.85 CM/SEC.

-MAXDELV	DEC	-6398		# 3200 PPS FOR 2 SEC CCS TAKES 1

JTAGTIME	DEC	120		# = 1 SEC + T CDU, T CDU = .1 SEC

2.5SEC		DEC	250
MDOTFAIL	DEC	144.0 B-16	# 5 SEC MASS LOSS AT 28.8 KG/SEC
					# SHOULD BE 2-4 SECS FOR NO START
					#	    6-8 SECS FOR FAILURE

# Page 831
# NORMLIZE PERFORMS THE INITIALIZATION REQUIRED PRIOR TO THE FIRST ENTRY TO AVERAGEG, AND SCALES RN SO THAT IT
# HAS 1 LEADING BINARY ZERO.  IN MOST MISSIONS, RN WILL BE SCALED AT 2(+29), BUT IN THE 206 MISSION, RN WILL BE
# SCALED AT 2(+24)M.

NORMLIZE	CAF	THIRTEEN	# SET UP TO COPY 14 REGS- RN1,VN1,PIPTIME1
		TC	GENTRAN		# INTO RN,VN, PIPTIME
		ADRES	RN1		# FROM HERE
		ADRES	RN		# TO HERE

		RELINT
		TC	INTPRET
		VLOAD	CALL		# LOAD RN FOR CALCGRAV
			RN
			CALCGRAV	# INITIALISE UNITR RMAG GDT1

		STOVL	GDT/2
			GOBL1/2
		STORE	GOBL/2
		EXIT
		TCF	ENDOFJOB

# Page 832
# *****  PIPA READER *****


# 		MOD NO. 00 BY D. LICKLY DEC.9 1966


# FUNCTIONAL DESCRIPTION

# 	SUBROUTINE TO READ PIPA COUNTERS, TRYING TO BE VERY CAREFUL SO THAT IT WILL BE RESTARTABLE.
# 	PIPA READINGS ARE STORED IN THE VECTOR DELV.  THE HIGH ORDER PART OF EACH COMPONENT CONTAINS THE PIPA READING,
# 	RESTARTS BEGIN AT REREADAC.


# 	AT THE END OF THE PIPA READER THE CDUS ARE READ AND STORED AS A
# VECTOR IN CDUTEMP.  THE HIGH ORDER PART OF EACH COMPONENT CONTAINS
# THE CDU READING IN 2S COMP IN THE ORDER CDUX,Y,Z.  THE THRUST
# VECTOR ESTIMATOR IN FINDCDUD REQUIRES THE CDUS BE READ AT PIPTIME.

# CALLING SEQUENCE AND EXIT

#	CALL VIA TC, ISWCALL, ETC.

#	EXIT IS VIA Q.


# INPUT

#	INPUT IS THROUGH THE COUNTERS PIPAX, PIPAY, PIPAZ, AND TIME2.


# OUTPUT

#	HIGH ORDER COMPONENTS OF THE VECTOR DELV CONTAIN THE PIPA READINGS.
#	PIPTIME CONTAINS TIME OF PIPA READING.


# DEBRIS (ERASABLE LOCATIONS DESTROYED BY THE PROGRAM)

#		LOW ORDER DELV'S ARE ZEROED FOR TM INDICATION.
#		TEMX	TEMY	TEMZ	PIPAGE

PIPASR		EXTEND
		DCA	TIME2
		DXCH	PIPTIME1	# CURRENT TIME	POSITIVE VALUE
		CS	ZERO		# INITIALIZE THESE AT NEG ZERO.
		TS	TEMX
		TS	TEMY
		TS	TEMZ
# Page 833
		CA	ZERO
		TS	DELVZ		# OTHER DELVS OK INCLUDING LOW ORDER
		TS	DELVY

		TS	DELVX +1	# LOW ORDER DELV'S ARE ZEROED FOR TM: THUS
		TS	DELVY +1	# IF DNLNK'D LOW ORDER DELVS ARE NZ, THEY
		TS	DELVZ +1	# CONTAIN PROPER COMPENSATION.  IF=0, THEN
					# THE TM VALUES ARE BEFORE COMPENSATION.

		TS	PIPAGE		# SHOW PIPA READING IN PROGRESS

REPIP1		EXTEND
		DCS	PIPAX		# X AND Y PIPS READ
		DXCH	TEMX
		DXCH	PIPAX		# PIPAS SET TO NEG ZERO AS READ.
		TS	DELVX
		LXCH	DELVY

REPIP3		CS	PIPAZ		# REPEAT PROCESS FOR Z PIP
		XCH	TEMZ
		XCH	PIPAZ
DODELVZ		TS	DELVZ

		TC	Q

		EBANK=	AOG

REREADAC	CCS	PHASE5		# LAST PASS CHECK
		TCF	+2
		TCF	TASKOVER

		CAF	PRIO31		# RESTART MAY HAVE WIPED OUT LASTBIAS, AN
		TS	1/PIPADT	#	UNPROTECTED NOVAC FROM PREREAD,
					#	WHICH SET(S) UP 1/PIPADT (THUSLY)
					#	FOR NON-COASTING COMPENSATION....BE
					#	SURE 1/PIPADT IS AOK.  (PRIO31 IS
					#	2.0SEC SC.AT B+8CS)

		CCS	PIPAGE
		TCF	READACCS	# PIP READING NOT STARTED.  GO TO BEGINNING

		CAF	DONEADR		# SET UP RETURN FROM PIPASR
		TS	Q

		CCS	DELVZ
		TC	Q		# Z DONE, GO DO CDUS
		TCF	+3		# Z NOT DONE, CHECK Y.
		TC	Q
		TC	Q
# Page 834
		ZL
		CCS	DELVY
		TCF	+3
		TCF	CHKTEMX		# Y NOT DONE, CHECK X.
		TCF	+1
		LXCH	PIPAZ		# Y DONE, ZERO Z PIP.

		CCS	TEMZ
		CS	TEMZ		# TEMZ NOT = -0, CONTAINS -PIPAZ VALUE.
		TCF	DODELVZ
		TCF	-2
		LXCH	DELVZ		# TEMZ = -0, L HAS ZPIP VALUE.
		TC	Q

CHKTEMX		CCS	TEMX		# HAS THIS CHANGED
		CS	TEMX		# YES
		TCF	+3		# YES
		TCF	-2		# YES
		TCF	REPIP1		# NO
		TS	DELVX

		CS	TEMY
		TS	DELVY

		CS	ZERO		# ZERO X AND Y PIPS
		DXCH	PIPAX		# L STILL ZERO FROM ABOVE

		TCF	REPIP3

DONEADR		GENADR	PIPSDONE

# Page 835
# *********************************************************************************************

# 	ROUTINE CALCRVG INTEGRATES THE EQUATIONS OF MOTION BY AVERAGING THE THRUST AND GRAVITATIONAL
# ACCELERATIONS OVER A TIME INTERVAL OF 2 SECONDS.
#
# 	FOR THE EARTH-CENTERED GRAVITATIONAL FIELD, THE PERTURBATION DUE TO OBLATENESS IS COMPUTED TO THE FIRST
# HARMONIC COEFFICIENT J.

# 	ROUTINE CALCRVG REQUIRES...
#		1) THRUST ACCELERATION INCREMENTS IN DELV SCALED SAME AS PIPAX,Y,Z IN STABLE MEMBER COORDS.
#		2) VN SCALED 2(+7)M/CS IN REFERENCE COORDS.
#		3) RN SCALED AT 2(+29) METERS IN REFERENCE COORDS.
#		4) UNITW THE EARTH S UNIT ROTATIONAL VECTOR (SCALED AS A FULL UNIT VECTOR) IN REFERENCE COORDS.

# IT LEAVES RN1 UPDATED (SCALED AT 2(+29)M, VN1 (SCALED AT 2(+7)M/CS), AND GDT1/2 (SCALED AT 2(+7)M/CS). ALSO HALF
# UNIT VECTOR UNITR, RMAG IN 36D SCALED AT 2(+29)M, R MAG SQ. IN 34D SCALED AT 2(+58) M SQ.

CALCGRAV	UNIT	PUSH		# ENTER WITH RN IN MPAC
		STORE 	UNITR
		LXC,1	SLOAD
			RTX2
			X1
		BMN	VLOAD
			ITISMOON
		DOT	PUSH
			UNITW
		DSQ	BDSU
			DP1/20
		PDDL	DDV
			RESQ
			34D		# (RN)SQ
		STORE	32D		# TEMP FOR (RE/RN)SQ
		DMP	DMP
			20J
		VXSC	PDDL
			UNITR
		DMP	DMP
			2J
			32D
		VXSC	VAD
			UNITW
		STADR
		STORE	GOBL1/2
		VAD	PUSH
			UNITR
ITISMOON	DLOAD	NORM
			34D
			X2
		BDDV*	SLR*
# Page 836
			-MUDT(E),1
			0 -21D,2
		VXSC	STADR
		STORE	GDT1/2		# SCALED AT 2(+7) M/CS
		RVQ

CALCRVG		VLOAD	VXSC
			DELV
			KPIP1
		VXM	VSL1
			REFSMMAT
		STORE	DELVREF		# DELV IN REF COORDS AT 2(+7)
		VSR1	PUSH
		VAD	PUSH		# (DV-OLDGDT)/2 TO PD SCALED AT 2(+7)M/CS
			GDT/2
		VAD	VXSC
			VN
			2SEC(22)
		VAD	STQ
			RN
			31D
		STCALL	RN1		# TEMP STORAGE OF RN SCALED 2(+29)M
			CALCGRAV

		VAD	VAD
		VAD
			VN
		STCALL	VN1		# TEMP STORAGE OF VN SCALED 2(+7)M/CS.
			31D

KPIP		2DEC	.1024		# SCALES DELV TO 2(+4)

KPIP1		2DEC	0.074880	# 207 DELV SCALING.  1 PULSE = 5.85 CM/SEC.

-MUDT(E)	2DEC*	-7.9720645 E+12 B-44*

-MUDT(M)	2DEC*	-9.805556 E+10 B-44*

2SEC(22)	2DEC	200 B-22

DP1/20		2DEC	0.05

RESQ		2DEC*	40.6809913 E12 B-59*

20J		2DEC*	3.24692010 E-2 B1*

2J		2DEC*	3.24692010 E-3 B1*