### FILE="Main.annotation"
## Copyright:   Public domain.
## Filename:	TVCEXECUTIVE.agc
## Purpose:     Part of the source code for Colossus build 237.
##              This is for the Command Module's (CM) Apollo Guidance
##              Computer (AGC), for Apollo 8.
## Assembler:   yaYUL
## Contact:     Jim Lawton <jim DOT lawton AT gmail DOT com>
## Website:     www.ibiblio.org/apollo/index.html
## Page Scans:  www.ibiblio.org/apollo/ScansForConversion/Colossus237/
## Mod history: 2011-03-06 JL	Adapted from corresponding Colossus 249 file.
##		2017-01-01 RSB	Proofed comment text using octopus/ProoferComments,
##				and fixed errors found.
##		2017-01-20 RSB	Fixed comment-text errors noted while diff'ing
##				vs Colossus 249.

## Page 900
# PROGRAM NAME.... TVCEXECUTIVE, CONSISTING OF TVCEXEC, NEEDLEUP, VARGAINS
#                  REPCHEK, SWTCHOVR, CG.CORR, STRKUP, TVCEXFIN, ETC.
# LOG SECTION....TVCEXECUTIVE     SUBROUTINE ....DAPCSM
# MOD BY ENGEL                    DATE 23 OCT, 1967

# FUNCTIONAL DESCRIPTION....

#     *A SELF-PERPETUATING WAITLIST TASK AT 1/2 SECOND INTERVALS WHICH:
#      PREPARES THE ROLL TVC DAP LADDERS
#      PREPARES THE ROLL FDAI NEEDLE (FLY-TO  OGA ERROR)
#      PREPARES THE ROLL PHASE PLANE  OGAERR  (FLY-FROM  OGA ERROR)
#      PREPARES THE TVC ROLLDAP TASK WAITLIST CALL (3 CS DELAY)
#      UPDATES THE NEEDLES DISPLAY
#      IMPLEMENTS VARIABLE GAINS AND VARIABLE VEHICLE MASS
#      PROVIDES FOR SWITCHOVER
#      PROVIDES FOR A SINGLE-SHOT THRUST MISALIGNMENT CORRECTION AT SWTOVR
#      PROVIDES FOR REPETITIVE THRUST MISALIGNMENT CORRECTIONS FOLLOWING
#      	    SWITCHOVER
#      PERFORMS CERTAIN STROKE TEST FUNCTIONS

# CALLING SEQUENCE....

#     *TVCEXEC CALLED AS A WAITLIST TASK, IN PARTICULAR BY TVCINIT4 AND BY
#      ITSELF, BOTH AT 1/2 SECOND INTERVALS

# NORMAL EXIT MODE.... TASKOVER

# ALARM OR ABORT EXIT MODES.... NONE

# SUBROUTINES CALLED....NEEDLER, S40.15, MASSPROP, TASKOVER, IBNKCALL

# OTHER INTERFACES....

#     *TVCRESTART PACKAGE FOR RESTARTS
#     *PITCHDAP, YAWDAP FOR VARIABLE GAINS AND ENGINE TRIM ANGLES
#     *S40.8 FOR KPRIMEDT AT SWITCHOVER

# ERASABLE INITIALIZATION REQUIRED....

#     *SEE TVCDAPON....TVCINIT4
#     *VARK AND 1/CONACC (S40.15 OF R03)
#     *V68 INITIALIZATION PRIOR TO SWITCHOVER OR FOLLOWING A RESTART
#      DURING A STROKE TEST, IF STROKE TEST FUNCTIONS ARE TO BE TESTED
#     *PAD LOADS EREPFRAC, ECORFRAC ETC.
#     *BITS 15,14 OF FLAGWRD6 (T5 BITS)
#     *TVCEXPHS FOR RESTARTS
#     *ENGINE-ON BIT (11.13) FOR RESTARTS
#     *CDUX, OGAD

# OUTPUT....
## Page 901
#     *ROLL TVC DAP LADDERS, FDAI NEEDLE (AK), AND PHASE PLANE OGAERR
#     *VARIABLE GAINS FOR PITCH/YAW AND ROLL TVC DAPS
#     *SINGLE-SHOT AND REPETITIVE CORRECTIONS TO ENGINE TRIM ANGLES
#      PACTOFF AND YACTOFF
#     *CHANGES TO DAP SAMPLE RATES, DAP GAINS, AND STEERING-GAIN SCALING
#      AT (LEM-ON) SWITCHOVER
#     *STROKER, 4 SECONDS AFTER SWITCHOVER WHEN PRIOR V66, OR 2.5
#      SECONDS AFTER RESTART DURING A STROKE TEST

# DEBRIS.... MUCH, BUT SHAREABLE WITH RCS/ENTRY, ALL IN EBANK6


		BANK	16
		SETLOC	DAPROLL
		BANK
		EBANK=	BZERO
		COUNT*	$$/TVCX
TVCEXEC		CS	FLAGWRD6	# CHECK FOR TERMINATION (BITS 15,14 READ
		MASK	OCT60000	#      10 FROM TVCDAPON TO RCSDAPON)
		EXTEND
		BZMF	TVCEXFIN	# TERMINATE

		CAF	.5SEC		# W.L. CALL TO PERPETUATE TVCEXEC
		TC	WAITLIST
		EBANK=	BZERO
		2CADR	TVCEXEC

ROLLPREP	CAE	CDUX		# UPDATE ROLL LADDERS (NO NEED TO RESTART-
		XCH	OGANOW		#      PROTECT, SINCE ROLL DAPS RE-START)
		XCH	OGAPAST

		CAE	OGAD		# PREPARE ROLL FDAI NEEDLE WITH FLY-TO
		EXTEND			#      ERROR (COMMAND - MEASURED)
		MSU	OGANOW
		TS	AK		# FLY-TO OGA ERROR, SC.AT B-1 REVS

		EXTEND			# PREPARE ROLL DAP PHASE PLANE  OGAERR
		MP	-BIT14	
		TS	OGAERR		# PHASE-PLANE (FLY-FROM) OGAERROR,
					#      SC.AT B+0 REVS

		CAF	THREE		# SET UP ROLL DAP TASK (ALLOW SOME TIME)
		TC	WAITLIST
		EBANK=	BZERO
		2CADR	ROLLDAP
NEEDLEUP	TC	IBNKCALL	# DO A NEEDLES UPDATE (RETURNS AFTER CADR)
		CADR	NEEDLER		#      (NEEDLES RESTARTS ITSELF)

## Page 902
VARGAINS	CAF	BIT13		# CHECK ENGINE-ON BIT TO INHIBIT VARIABLE
		EXTEND			#      GAINS AND MASS IF ENGINE OFF
		RAND	DSALMOUT	# CHANNEL 11
		CCS	A
		TCF	+4		#     ON , SO OK TO UPDATE GAINS AND MASS
  +5		CAF	TWO		#      OFF, SO BYPASS MASS/GAIN UPDATES,
		TS	TVCEXPHS	#      	    ALSO ENTRY FROM CCS BELOW WITH
		TCF	SWT/COR		#      	    VCNTR = -0 (V97 R40 ENGFAIL)

		CCS	VCNTR		#      TEST FOR GAIN UPDATE TIME
		TCF	+4		#           NOT YET
		TCF	GAINCHNG	#           NOW
		TCF	+0		#           NOT USED
		TCF	VARGAINS +5	#           NO, LOTHRUST (S40.8 R40)

  +4		TS	VCNTRTMP	#      PROTECT VCNTR AND
		CAE	CSMMASS		#     CSMMASS DURING AN IMPULSIVE BURN
		TS	MASSTMP
		TCF	EXECCOPY

GAINCHNG	TC	IBNKCALL	# UPDATE IXX, IAVG, IAVG/TLX
		CADR	FIXCW		# MASSPROP ENTRY  (ALREADY INITIALIZED)
		TC	S40.15		# UPDATE 1/CONACC, VARK
		CS	TENMDOT		# UPDATE MASS FOR NEXT 10 SEC. OF BURN
		AD	CSMMASS
		TS	MASSTMP		# KG B+16

		CAF	NINETEEN	# RESET THE VARIABLE-GAIN UPDATE COUNTER
NOUPDATE	TS	VCNTRTMP	# (COUNTDOWN, FROM VARGAINS +1)

EXECCOPY	INCR	TVCEXPHS	# RESTART-PROTECT THE COPYCYCLE        (1)

		CAE	MASSTMP		# CSMMASS KG B+16
		TS	CSMMASS

		CAE	VCNTRTMP	# VCNTR
		TS	VCNTR
		TS	V97VCNTR	# FOR ENGFAIL (R41) MASS UPDATES AT SPSOFF

		INCR	TVCEXPHS	# COPYCYCLE OVER                       (2)

SWT/COR		CCS	CNTR		# CHECK FOR SWITCHOVER/CG.CORRECTION
		TCF	+4		#      NOT YET
		TCF	SWTCHOVR	#      NOW
		TCF	REPCHEK		#      PRIOR SWITCHOVER (OR NONE)
		TCF	SWTCHOVR	#      NOW (1/2 SEC SWITCHOVER, ONLY)

  +4		TS	CNTRTMP		# COUNT DOWN
		CAF	SEVEN		# SETUP TVCEXPHS FOR ENTRY AT CNTRCOPY
		TS	TVCEXPHS
## Page 903
		TCF	CNTRCOPY

REPCHEK		CAE	REPFRAC		# CHECK FOR REPETITIVE UPDATES
		EXTEND
		BZMF	+5		#      NO   (NEG OR +-ZERO)
		TS	TEMPDAP +1	#      YES, SET UP CORRECTION FRACTION
		CAF	FIVE		#           ADVANCE TVCEXPHS
		TS	TVCEXPHS
		TCF	CORSETUP

  +5		CAF	EIGHT
		TS	TVCEXPHS
		TCF	STRKUP

SWTCHOVR	CAF	BIT13		# CHECK ENGINE-ON BIT, NOT PERMITTING
		EXTEND			#      SWITCHOVER DURING ENGINE-SHUTDOWN
		RAND	DSALMOUT	#      TAILOFF
		CCS	A
		TCF	+2		# OK TO SWITCHOVER
		TCF	TVCEXFIN	# DONT SWITCHOVER, TERMINATE

		CS	FLAGWRD9	# SET SWITCHOVER FLAG (SWTOVER) FOR DWNLNK
		MASK	BIT15		#      AND POST-BURN TRIM UPDATES (SEE
		ADS	FLAGWRD9	#      ..BESTTRIM.. (P40-P47))

		CAE	DAPDATR1	# SWITCHOVER....CHECK FOR LEM-OFF/ON
		MASK	BIT13		# (NOTE, SHOWS LEM-OFF)
		EXTEND
		BZF	GAINDOWN	# LEM-ON....FULL SWITCHOVER/CG.CORRECTION

		CAF	FOUR		# LEM-OFF....NO SWITCHOVER, JUST CG.CORR.
		TS	TVCEXPHS
		TCF	TEMPSET

GAINDOWN	CAE	ETVCDT/2	# LEM-ON.... DROP GAIN BY (OLDTVCDT/8CS)SQ
		EXTEND
		MP	BIT5
		LXCH	A
		EXTEND
		MP	A
		LXCH	A		# (TVCDT/8CS)SQD, SC.AT 8+2

		EXTEND			# PREPARE NEW GAIN CONSTANT
		MP	KTLX/I
		DDOUBL
		DDOUBL
		TS	TKTLX/I		# (FOR COPYCYCLE)

SWTCOPY		INCR	TVCEXPHS	# RESTART-PROTECT THE COPYCYCLE	       (3)

## Page 904
		CAF	OCT37774	# LEM-ON ONLY..... T5 TIMER
		TS	T5TVCDT

		CAE	EKPRIME +1	# PREPARE KPRIMEDT FOR 80MS DAP, USING
		DOUBLE
		DOUBLE
		TS	KPRIMEDT	#      (KPRIMEDT+1 IS ZERO)

#					  SCALING OF OMEGAC HAS CHANGED, BUT NO
#					       CHANGE OF REGISTERS.  RATE COMMANDS
#					       ARE LOW BY  (OLD TVCDT)/80,  UNTIL
#					       NEXT S40.6 COMPUTATION, WHICH USES
#					       THE NEW  KPRIMEDT.

		CAE	TKTLX/I		# GAIN CONSTANT
		TS	KTLX/I

		TC	S40.15 +7	# UPDATE VARK (ONLY, NO CHANGE 1/CONACC)

STRKCALL	CCS	STROKER		# CHECK STROKER FOR VERB 68 INDICATION
		TCF	+5		#      STROKE TEST IN PROGRESS (80MS DAP)
		TCF	+4		#      +0 SAYS NO VERB 68 YET
		TCF	+3		#      STROKE TEST IN PROGRESS (80MS DAP)
		CAF	EIGHT		#      -0 SAYS PRIOR VERB68, SO START
		TS	STRKTIME	#           STROKE TEST IN 4 SECONDS

  +543		INCR	TVCEXPHS	# COPYCYCLE OVER (SWTCHOVR ENTRY NEXT) (4)

TEMPSET		CAE	ECORFRAC	#      	SET UP CORRECTION FRACTION
		TS	TEMPDAP +1

		INCR	TVCEXPHS	# ENTRY FROM REPCHECK AT NEXT LOCATION (5)

CORSETUP	CAE	DAPDATR1	# CHECK FOR LEM-OFF/ON
		MASK	BIT13		# (NOTE, SHOWS LEM-OFF)
		EXTEND
		BZF	+2		# LEM IS ON,  PICK UP   TEMPDAP+1
		CAE	TEMPDAP +1	# LEM IS OFF, PICK UP 2(TEMPDAP+1)
		AD	TEMPDAP +1
		TS	TEMPDAP		# CG.CORR USES TEMPDAP

		CAF	NEGONE		# SET UP FOR CNTR = -1 (SWTCHOVR DONE)
		TS	CNTRTMP		#      (COPYCYCLE AT  .CNTRCOPY. )

CG.CORR		EXTEND			# PITCH TRIM-TRACKER CORRECTION
		DCA	PDELOFF
		DXCH	PACTTMP
		CS	PACTOFF
		AD	DELPBAR
		EXTEND
## Page 905
		MP	TEMPDAP
		DDOUBL
		DDOUBL
		DAS	PACTTMP

		EXTEND
		DCA	YDELOFF
		DXCH	YACTTMP
		CS	YACTOFF
		AD	DELYBAR
		EXTEND
		MP	TEMPDAP
		DDOUBL
		DDOUBL
		DAS	YACTTMP

CORCOPY		INCR	TVCEXPHS	# RESTART-PROTECT THE COPYCYCLE        (6)

		EXTEND			# TRIM-ESTIMATES, AND
		DCA	PACTTMP
		TS	PACTOFF		#	TRIMS
		DXCH	PDELOFF

		EXTEND
		DCA	YACTTMP
		TS	YACTOFF
		DXCH	YDELOFF

		INCR	TVCEXPHS	# COPYCYCLE OVER (SWT/COR ENTRY NEXT)  (7)

CNTRCOPY	CAE	CNTRTMP		# UPDATE CNTR (RESTARTS OK, FOLLOWS CPYCY)
		TS	CNTR

		INCR	TVCEXPHS	# ENTRY FROM REPCHECK AT NEXT LOCATION (8)

STRKUP		CCS	STRKTIME	# CHECK STROKE TEST START TIME
		TCF	+3		#      IN 4SEC DELAY AFTER SWITCHOVER
		TCF	STRKNOW		#      START STROKE TEST NOW....
		TCF	TVCEXFIN	#      NO STROKE TEST REQUEST YET

		TS	STRKTTMP	# COUNT DOWN
		TCF	STRKTCPY

STRKNOW		CAE	ESTROKER	# START THE STROKE TEST NOW....
		TS	STROKER
		CAF	NEGONE		# KILL THE STROKE TEST CALL
		TS	STRKTTMP

STRKTCPY	INCR	TVCEXPHS	# RESTART-PROTECT THE COPYCYCLE        (9)

## Page 906
		CAE	STRKTTMP
		TS	STRKTIME

TVCEXFIN	CAF	ZERO		# RESET TVCEXPHS
		TS	TVCEXPHS

		TCF	TASKOVER	# OVER AND OUT

## Page 907
# NAME     S40.15 INERTIA COMPUTATIONS
		EBANK=	1/CONACC

S40.15		CAE	IXX		# COMPUTE 1/CONACC (RACC)....IXX SC.AT
		EXTEND			#      B+20  KG M SQD
		MP	2PI/M		# 2PI/M, SC.AT  1/(B+8 N M)
		DDOUBL
		DDOUBL
		DDOUBL
		TS	1/CONACC	# SC.AT  B+9  SEC SQD / REV

  +7		CAE	KTLX/I		# COMPUTE VARK, SCALING IN THE KTLX/I FOR
		EXTEND			#      LM-OFF,ON. ENTRY FROM SWITCHOVER
		MP	IAVG/TLX	#      SCALED AT B+2  SECONDS-SQUARED
		DDOUBL			#      SCALING
		DDOUBL
		DDOUBL
		TS	VARK		#      LEM-OFF KPGEN3(0) OR LEM-ON VARK(0)

		TC	Q

2PI/M		DEC	.00331017 B+8	# 2PI/M, SC.AT 1/(B+8 N M)