# Copyright:	Public domain.
# Filename:	P76.agc
# Purpose: 	Part of the source code for Luminary 1A build 099.
#		It is part of the source code for the Lunar Module's (LM)
#		Apollo Guidance Computer (AGC), for Apollo 11.
# Assembler:	yaYUL
# Contact:	Ron Burkey <info@sandroid.org>.
# Website:	www.ibiblio.org/apollo.
# Pages:	709-711
# Mod history:	2009-05-19 RSB	Adapted from the corresponding
#				Luminary131 file, using page
#				images from Luminary 1A.
#
# This source code has been transcribed or otherwise adapted from
# digitized images of a hardcopy from the MIT Museum.  The digitization
# was performed by Paul Fjeld, and arranged for by Deborah Douglas of
# the Museum.  Many thanks to both.  The images (with suitable reduction
# in storage size and consequent reduction in image quality as well) are
# available online at www.ibiblio.org/apollo.  If for some reason you
# find that the images are illegible, contact me at info@sandroid.org
# about getting access to the (much) higher-quality images which Paul
# actually created.
#
# Notations on the hardcopy document read, in part:
#
#	Assemble revision 001 of AGC program LMY99 by NASA 2021112-61
#	16:27 JULY 14, 1969

# Page 709
# 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 INIITIALIZATION 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, CMOONFLG, INTYPFLG, RASFLAG, AND MARKCTR.

		BANK	30
		SETLOC	P76LOC
		BANK

		COUNT*	$$/P76

		EBANK=	TIG

P76		TC	UPFLAG
		ADRES	TRACKFLG

		TC	INTPRET
		VLOAD
			DELVLVC
		STORE	DELVOV
		EXIT

		CAF	V06N84		# FLASH LAST DELTA V,
		TC	BANKCALL	# AND WAIT FOR KEYBOARD ACTION.
		CADR	GOFLASH
		TCF	ENDP76
		TC	+2		# PROCEED
		TC	-5		# STORE DATA AND REPEAT FLASHING
		CAF	V06N84 +1	# FLASH VERB 06 NOUN 33, DISPLAY LAST TIG,
		TC	BANKCALL	# AND WAIT FOR KEYBOARD ACTION.
		CADR	GOFLASH
		TCF	ENDP76
		TC	+2
		TC	-5
		TC	INTPRET		# RETURN TO INTERPRETIVE CODE
# Page 710
		DLOAD			# SET D(MPAC)=TIG IN CSEC B28
			TIG
		STCALL	TDEC1		# SET TDEC1=TIG FOR ORBITAL INTEGRATION
			OTHPREC
COMPMAT		VLOAD	UNIT
			RATT
		VCOMP			# U(-R)
		STORE	24D		# U(-R) TO 24D
		VXV	UNIT		# U(-R) XV = U(VXR)
			VATT
		STORE	18D
		VXV	UNIT		# U(VXR)XU(-R) = U((RXV)XR)
			24D
		STOVL	12D
			DELVOV
		VXM	VSL1		# V(MPAC)=DELTA V IN REFCOSYS
			12D
		VAD
			VATT
		STORE	6		# V(PD6)=VATT + DELTA V
		CALL			# PRESENT 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
		CLEAR	DLOAD
			INTYPFLG
			TETTHIS
INTOTHIS	STCALL	TDEC1
			INTEGRVS
		CALL
			INTSTALL
		VLOAD
			RATT1
		STORE	RRECT
		STODL	RCV
			TAT
		STOVL	TET
			VATT1
		CALL
			MINIRECT
# Page 711
		EXIT
		TC	PHASCHNG
		OCT	04024

		TC	UPFLAG
		ADRES	REINTFLG

		TC	INTPRET
		CALL
			ATOPOTH
		SSP	EXIT
			QPRET
			OUT
		TC	BANKCALL	# PERMIT USE OF ORBITAL INTEGRATION
		CADR	INTWAKE1
OUT		EXIT
ENDP76		CAF	ZERO
		TS	MARKCTR		# CLEAR RR TRACKING MARK COUNTER
		TCF	GOTOPOOH

V06N84		NV	0684
		NV	0633
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
