### FILE="Main.annotation"
## Copyright:   Public domain.
## Filename:    P76.agc
## Purpose:     A section of Luminary revision 210.
##              It is part of the source code for the Lunar Module's (LM)
##              Apollo Guidance Computer (AGC) for Apollo 15-17.
##              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. 711-714
## Assembler:   yaYUL
## Contact:     Ron Burkey <info@sandroid.org>.
## Website:     www.ibiblio.org/apollo/index.html
## Mod history: 2016-11-17 JL   Created from Luminary131 version.
##		2016-12-01 RSB	Completed.
##              2016-12-01 HG   Add missing instructions for INTADR, UPDATADR
##                              fix operand GOTOPOOH  -> GOTOP00H
##              2016-12-07 HG   'unfix' and revert P00 -> POO
##              2016-12-11 HG   Fix operand -5 -> -6
##		2016-12-25 RSB	Comment-text proofed using ProoferComments
##				and corrected errors found.


## Page 711
# 1) PROGRAM NAME - TARGET DELTA V PROGRAM (P76).
# 2) FUNCTIONAL DESCRIPTION - UPON ENTRY BY ASTRONAUT ACTION, P76 FLASHES DSKY REQUESTS TO THE ASTRONAUT
#    	   TO PROVIDE VIA DSKY (1) THE DELTA V TO BE APPLIED TO THE OTHER VEHICLE STATE VECTOR AND (2) THE
#          TIME (TIG) AT WHICH THE OTHER VEHICLE VELOCITY WAS CHANGED BY  EXECUTION OF A THRUSTING MANEUVER. THE
#          OTHER VEHICLE STATE VECTOR IS INTEGRATED TO TIG AND UPDATED BY THE ADDITION OF DELTA V (DELTA V HAVING
#          BEEN TRANSFORMED FROM LV TO REF COSYS).  USING INTEGRVS, THE   PROGRAM THEN INTEGRATES THE OTHER
# VEHICLE STATE VECTOR TO THE STATE VECTOR OF THIS VEHICLE, THUS INSURING THAT THE W-MATRIX AND BOTH VEHICLE
# STATES CORRESPOND TO THE SAME TIME.
# 3) ERASABLE INITIALIZATION REQUIRED - NONE.
# 4) CALLING SEQUENCES AND EXIT MODES - CALLED BY ASTRONAUT REQUEST THRU DSKY V 37 E 76 E.
#          EXITS BY TCF ENDOFJOB.
# 5) OUTPUT - OTHER VEHICLE STATE VECTOR INTEGRATED TO TIG AND INCREMENTED BY DELTA V IN REF COSYS.
#          THE PUSHLIST CONTAINS THE MATRIX BY WHICH THE INPUT DELTA V MUST BE POST-MULTIPLIED TO CONVERT FROM LV
#          TO REF COSYS.
# 6) DEBRIS - OTHER VEHICLE STATE VECTOR.
# 7) SUBROUTINES CALLED - BANKCALL,GOXDSPF,CSMPREC (OR LEMPREC),ATOPCSM (OR ATOPLEM),INTSTALL,INTWAKE, PHASCHNG
#          INTPRET, INTEGRVS, AND MINIRECT.

# 8) FLAG USE - MOONFLAG,CMOONFLAG,INTYPFLG,RASFLAG, AND MARKCTR.

		BANK	30
		SETLOC	P76LOC
		BANK

		COUNT*	$$/P76

		EBANK=	TIG

P76ER77		CA	MODREG
		MASK	BIT1
		TS	OPTFLAG		# OPTFLAG = 0  CM (P76)
		TC	UPFLAG		#         = 1  LM (P77)
		ADRES	TRACKFLG

		TC	INTPRET
		VLOAD
			DELVLVC
		STORE	DELVOV
		EXIT

		CAF	V06N3376
		TC	BANKCALL	# AND WAIT FOR KEYBOARD ACTION.
		CADR	GOFLASH
		TCF	ENDP76
		TC	+2		# PROCEED
		TC	-5		# STORE DATA AND REPEAT FLASHING
		TC	PHASCHNG
		OCT	04024
		INDEX	OPTFLAG
		CAF	V06N84		# FLASH V06 N84 (OR N81), LAST DELTV,
## Page 712		
		TC	BANKCALL	# AND WAIT FOR KEYBOARD ACTION.
		CADR	GOFLASH
		TCF	ENDP76
		TC	+2
		TC	-6		# STORE DATA & REPEAT FLASHING DSP
		TC	INTPRET		# RETURN TO INTERPRETIVE CODE
		DLOAD	SET
			TIG
			NODOFLAG
		STORE	TDEC1
		CCALL
			OPTFLAG
			INTADR
COMPMAT		VLOAD	UNIT
			RATT
		VCOMP			# U(-R)
		STORE	24D		# U(-R) TO 24D
		VXV	UNIT		# U(-R) X V = U(V X R)
			VATT
		STORE	18D
		VXV	UNIT		# U(V X R) X U(-R) = U((R X V) X R)
			24D
		STORE	12D
		SLOAD	BHIZ
			OPTFLAG
			+4
		VLOAD
			DELVLVC		# FROM CM
		STORE	DELVOV
		VLOAD
			DELVOV		# FROM LM
DVTRANS		VXM	VSL1		# V(MPAC)=DELTA V IN REFCOSYS
			12D
		VAD
			VATT
		STORE	6		# V(PD6)=VATT + DELTA V
		CALL			# PREVENT WOULD-BE USER OF ORBITAL
			INTSTALL	# INTEG FROM INTERFERING WITH UPDATING
		CALL
			P76SUB1
		VLOAD	VSR*
			6
			0,2
		STOVL	VCV
			RATT
		VSR*
			0,2
		STODL	RCV
			TIG
		STORE	TET
## Page 713
		CLEAR	DLOAD
			INTYPFLG
			TETTHIS
INTOTHIS	STCALL	TDEC1
			INTEGRVS
		CALL
			INTSTALL
		VLOAD
			RATT1
		STORE	RRECT
		STODL	RCV
			TAT
		STOVL	TET
			VATT1
		CALL
			MINIRECT
		EXIT
		TC	PHASCHNG
		OCT	04024

		TC	INTPRET
		SET	CCALL
			REINTFLG
			OPTFLAG
			UPDATADR
		CALL
			INTWAKE0
OUT		CLEAR	EXIT		# ALLOW V37.  NO NEED TO CLEAR NODOFLAG AT
			NODOFLAG	#  ENDP76 SINCE FLAG NOT SET WHEN DISPLAY
					#  RESPONSES TRANSFER THERE FROM P76+.
ENDP76		CAF	ZERO
		TS	MARKCTR		# CLEAR RR TRACKING MARK COUNTER
		TCF	GOTOPOOH

V06N84		NV	0684
		NV	0681
V06N3376	NV	0633
INTADR          CADR    OTHPREC
                CADR    THISPREC
UPDATADR        CADR    ATOPOTH
                CADR    ATOPTHIS
P76SUB1		AXT,2	SET
			2
			MOONFLAG	# SET MEANS MOON IS SPHERE OF INFLUENCE.
		BON	AXT,2
			CMOONFLG	# SET MEANS PERM CM STATE IN LUNAR SPHERE.
			QPRET
			0
		CLEAR	RVQ
			MOONFLAG

## Page 714
## This page is completely blank in the original assembly-listing hardcopy.