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	* Update GROUND_TRACKING_DETERMINATION_PROGRAM.agc * Apply suggestions from code review * Recommended character change and spacing changes * Apply suggestions from code review Co-authored-by: James Harris <wopian@wopian.me>
		
			
				
	
	
		
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			209 lines
		
	
	
		
			4.7 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| # Copyright:	Public domain.
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| # Filename:	GROUND_TRACKING_DETERMINATION_PROGRAM.agc
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| # Purpose: 	Part of the source code for Luminary 1A build 099.
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| #		It is part of the source code for the Lunar Module's (LM)
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| #		Apollo Guidance Computer (AGC), for Apollo 11.
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| # Assembler:	yaYUL
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| # Contact:	Ron Burkey <info@sandroid.org>.
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| # Website:	www.ibiblio.org/apollo.
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| # Pages:	654-657
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| # Mod history:	2009-05-18 RSB	Adapted from the corresponding
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| #				Luminary131 file, using page
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| #				images from Luminary 1A.
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| #
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| # This source code has been transcribed or otherwise adapted from
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| # digitized images of a hardcopy from the MIT Museum.  The digitization
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| # was performed by Paul Fjeld, and arranged for by Deborah Douglas of
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| # the Museum.  Many thanks to both.  The images (with suitable reduction
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| # in storage size and consequent reduction in image quality as well) are
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| # available online at www.ibiblio.org/apollo.  If for some reason you
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| # find that the images are illegible, contact me at info@sandroid.org
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| # about getting access to the (much) higher-quality images which Paul
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| # actually created.
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| #
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| # Notations on the hardcopy document read, in part:
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| #
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| #	Assemble revision 001 of AGC program LMY99 by NASA 2021112-061
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| #	16:27 JULY 14, 1969
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| 
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| # Page 654
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| # GROUND TRACKING DETERMINATION PROGRAM P21
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| # PROGRAM DESCRIPTION
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| # MOD NO - 1
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| # MOD BY - N.M.NEVILLE
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| # FUNCTIONAL DECRIPTION-
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| #
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| # TO PROVIDE THE ASTRONAUT DETAILS OF THE LM OR CSM GROUND TRACK WITHOUT
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| # THE NEED FOR GROUND COMMUNICATION (REQUESTED BY DSKY).
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| # CALLING SEQUENCE -
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| #
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| # ASTRONAUT REQUEST THROUGH DSKY V37E21E
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| # SUBROUTINES CALLED-
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| #
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| # GOPERF4
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| # GOFLASH
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| # THISPREC
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| # OTHPREC
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| # LAT-LONG
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| # NORMAL EXIT MODES-
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| #
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| # ASTRONAUT REQUEST TROUGH DSKY TO TERMINATE PROGRAM V34E
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| # ALARM OR ABORT EXIT MODES-
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| #
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| # NONE
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| # OUTPUT -
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| #
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| # OCTAL DISPLAY OF OPTION CODE AND VEHICLE WHOSE GROUND TRACK IS TO BE
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| # COMPUTED
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| #	OPTION CODE	00002
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| #	THIS		00001
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| #	OTHER		00002
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| # DECIMAL DISPLAY OF TIME TO BE INTEGRATED TO HOURS , MINUTES , SECONDS
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| # DECIMAL DISPLAY OF LAT,LONG,ALT
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| # ERASABLE INITIALIZATION REQUIRED
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| #
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| # AXO		2DEC	4.652459653 E-5		RADIANS		%68-69 CONSTANTS"
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| #
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| # -AYO		2DEC	2.147535898 E-5		RADIANS
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| #
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| # AZO		2DEC	.7753206164		REVOLUTIONS
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| # FOR LUNAR ORBITS 504LM VECTOR IS NEEDED
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| #
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| # 504LM		2DEC	-2.700340600 E-5	RADIANS
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| #
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| # 504LM	_2	2DEC	-7.514128400 E-4	RADIANS
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| #
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| # 504LM	_4	2DEC	_2.553198641 E-4	RADIANS
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| #
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| # NONE
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| # DEBRIS
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| #
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| # Page 655
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| # CENTRALS-A,Q,L
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| # OTHER-THOSE USED BY THE ABOVE LISTED SUBROUTINES
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| # SEE LEMPREC,LAT-LONG
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| 		SBANK=	LOWSUPER	# FOR LOW 2CADR'S.
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| 
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| 		BANK	33
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| 		SETLOC	P20S
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| 		BANK
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| 
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| 		EBANK=	P21TIME
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| 		COUNT*	$$/P21
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| PROG21		CAF	ONE
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| 		TS	OPTION2		# ASSUMED VEHICLE IS LM , R2 = 00001
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| 		CAF	BIT2		#  OPTION 2
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| 		TC	BANKCALL
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| 		CADR	GOPERF4
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| 		TC	GOTOPOOH	# TERMINATE
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| 		TC	+2		# PROCEED VALUE OF ASSUMED VEHICLE OK
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| 		TC	-5		# R2 LOADED THROUGH DSKY
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| P21PROG1	CAF	V6N34		# LOAD DESIRED TIME OF LAT-LONG.
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| 		TC	BANKCALL
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| 		CADR	GOFLASH
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| 		TC	GOTOPOOH	# TERM
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| 		TC	+2		# PROCEED VALUES OK
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| 		TC	-5		# TIME LOADED THROUGH DSKY
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| 		TC	INTPRET
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| 		DLOAD
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| 			DSPTEM1
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| 		STCALL	TDEC1		# INTEGRATE TO TIME SPECIFIED IN TDEC
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| 			INTSTALL
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| 		BON	CLEAR
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| 			P21FLAG
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| 			P21CONT		# ON---RECYCLE USING BASE VECTOR
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| 			VINTFLAG	# OFF--IST PASS CALL BASE VECTOR
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| 		SLOAD	SR1
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| 			OPTION2
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| 		BHIZ	SET
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| 			+2		# ZERO--THIS VEHICLE(LM)
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| 			VINTFLAG	# ONE--OTHER VEHICLE(CM)
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| 		CLEAR	CLEAR
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| 			DIM0FLAG
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| 			INTYPFLG	# PRECISION
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| 		CALL
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| 			INTEGRV		# CALCULATE
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| 		GOTO			# -AND
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| 			P21VSAVE	# -SAVE BASE VECTOR
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| P21CONT		VLOAD
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| 			P21BASER	# RECYCLE--INTEG FROM BASE VECTOR
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| 		STOVL	RCV		# --POS
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| # Page 656
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| 			P21BASEV
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| 		STODL	VCV		# --VEL
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| 			P21TIME
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| 		STORE	TET		# --TIME
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| 		CLEAR	CLEAR
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| 			DIM0FLAG
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| 			MOONFLAG
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| 		SLOAD	BZE
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| 			P21ORIG
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| 			+3		# ZERO=EARTH
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| 		SET			# ---2=MOON
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| 			MOONFLAG
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|  +3		CALL
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| 			INTEGRVS
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| P21VSAVE	DLOAD			# SAVE CURRENT BASEVECTOR
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| 			TAT
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| 		STOVL	P21TIME		# --TIME
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| 			RATT1
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| 		STOVL	P21BASER	# --POS B-29 OR B-27
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| 			VATT1
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| 		STORE	P21BASEV	# --VEL B-07 OR B-05
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| 		ABVAL	SL*
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| 			0,2
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| 		STOVL	P21VEL		# VEL/ FOR N91 DISP
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| 			RATT
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| 		UNIT	DOT
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| 			VATT		#  U(R).V
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| 		DDV	ASIN		# U(R).U(V)
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| 			P21VEL
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| 		STORE	P21GAM		# SIN-1 U(R).U(V) , -90 TO &90
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| 		SXA,2	SLOAD
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| 			P21ORIG		# 0=EARTH
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| 			OPTION2
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| 		SR1	BHIZ
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| 			+3
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| 		GOTO
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| 			+4
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|  +3		BON
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| 			SURFFLAG
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| 			P21DSP
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|  +4		SET
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| 			P21FLAG
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| P21DSP		CLEAR	SLOAD		# GENERATE DISPLAY DATA
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| 			LUNAFLAG
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| 			X2
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| 		BZE	SET
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| 			+2		# 0 = EARTH
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| 			LUNAFLAG
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| 		VLOAD
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| 			RATT
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| # Page 657
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| 		STODL	ALPHAV
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| 			TAT
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| 		CLEAR	CALL
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| 			ERADFLAG
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| 			LAT-LONG
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| 		DMP			# MPAC = ALT, METERS B-29
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| 			K.01
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| 		STORE	P21ALT		# ALT/100 FOR N91 DISP
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| 		EXIT
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| 		CAF	V06N43		# DISPLAY LAT, LONG, ALT
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| 		TC	BANKCALL	# LAT, LONG = 1/2 REVS B0
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| 		CADR	GOFLASH		# ALT = KM B14
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| 		TC	GOTOPOOH	# TERM
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| 		TC	GOTOPOOH
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| 		TC	INTPRET		# V32E RECYCLE
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| 		DLOAD	DAD
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| 			P21TIME
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| 			600SEC		# 600 SECONDS OR 10 MIN
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| 		STORE	DSPTEM1
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| 		RTB
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| 			P21PROG1
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| 600SEC		2DEC	60000		# 10 MIN
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| 
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| V06N43		VN	00643
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| V6N34		VN	00634
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| K.01		2DEC	.01
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