### FILE="Main.annotation"
## Copyright:	Public domain.
## Filename:	RCS-CSM_DAP_EXECUTIVE_PROGRAMS.agc
## Purpose:	Part of the source code for Colossus, build 249.
##		It is part of the source code for the Command Module's (CM)
##		Apollo Guidance Computer (AGC), for Apollo 9.
## Assembler:	yaYUL
## Reference:	Starts on p. 1008
## Contact:	Ron Burkey <info@sandroid.org>.
## Website:	www.ibiblio.org/apollo.
## Mod history:	08/26/04 RSB.	Began transcribing.
##		2017-01-06 RSB	Page numbers now agree with those on the
##				original harcopy, as opposed to the PDF page
##				numbers in 1701.pdf.
##		2017-01-18 RSB	Cross-diff'd comment text (not whitespace)
##				vs the already-proofed corresponding Colossus
##				237 and Comanche 55 source-code files
##				but no errors found.
##
## The contents of the "Colossus249" files, in general, are transcribed 
## from a scanned copy of the program listing.  Notations on this
## document read, in part:
##
##	Assemble revision 249 of AGC program Colossus by NASA
##	2021111-041.  October 28, 1968.  
##
##	This AGC program shall also be referred to as
##				Colossus 1A
##
##	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 (relative to the scanned pages) to info@sandroid.org.
##
## In some cases, where the source code for Luminary 131 overlaps that of 
## Colossus 249, this code is instead copied from the corresponding Luminary 131
## source file, and then is proofed to incorporate any changes.

## Page 1008
# CALCULATION OF  AMGB, AMBG  ONCE EVERY SECOND
#
#	AMGB =	1	SIN(PSI)		0
#		0	COS(PSI)COS(PHI)	SIN(PHI)
#		0	-COS(PSI)SIN(PHI)	COS(PHI)
#
#	AMBG =	1	-TAN(PSI)COS(PHI)	TAN(PSI)SIN(PHI)
#		0	COS(PHI)/COS(PSI)	-SIN(PHI)/COS(PSI)
#		0	SIN(PHI)		COS(PHI)
#
# WHERE PHI AND PSI ARE CDU ANGLES

		BANK	20
		SETLOC	DAPS8
		BANK
		
		COUNT*	$$/DAPEX
		EBANK=	KMPAC
AMBGUPDT	CA	FLAGWRD6	# CHECK FOR RCS AUTOPILOT
		EXTEND
		BZMF	ENDOFJOB	# BIT15 = 0, BIT14 = 1
		MASK	BIT14		# IF NOT RCS, EXIT
		EXTEND
		BZF	ENDOFJOB	# TO PROTECT TVC DAP ON SWITCHOVER
		
		CA	CDUZ	
		TC	SPSIN2
		TS	AMGB1		# CALCULATE AMGB
		CA	CDUZ
		TC	SPCOS2
		TS	CAPSI		# MUST CHECK FOR GIMBAL LOCK
		CAF	QUADANGL	# = 7.25  DEGREES JET QUAD ANGULAR OFFSET
		EXTEND
		MSU	CDUX
		COM			# CDUX - 7.25 DEG
		TC	SPCOS1
		TS	AMGB8
		EXTEND
		MP	CAPSI
		TS	AMGB4
		CAF	QUADANGL
		EXTEND
		MSU	CDUX
		COM			# CDUX - 7.25 DEG
		TC	SPSIN1
		TS	AMGB5
		EXTEND
		MP	CAPSI
		COM
## Page 1009
		TS	AMGB7
		TCF	ENDOFJOB
QUADANGL	DEC	660		# = 7.25 DEGREES