### FILE="Main.annotation"
## Copyright:	Public domain.
## Filename:	RADAR_LEADIN_ROUTINES.agc
## Purpose:	Part of the reconstructed source code for LMY99 Rev 0,
##		otherwise known as Luminary Rev 99, the second release
##		of the Apollo Guidance Computer (AGC) software for Apollo 11.
##		It differs from LMY99 Rev 1 (the flown version) only in the
##		placement of a single label. The corrections shown here have
##		been verified to have the same bank checksums as AGC developer
##		Allan Klumpp's copy of Luminary Rev 99, and so are believed
##		to be accurate. This file is intended to be a faithful 
##		recreation, except that the code format has been changed to 
##		conform to the requirements of the yaYUL assembler rather than 
##		the original YUL assembler.
##
## Assembler:	yaYUL
## Contact:	Ron Burkey <info@sandroid.org>.
## Website:	www.ibiblio.org/apollo.
## Pages:	490-491
## Mod history:	2009-05-17 RSB	Adapted from the corresponding 
##				Luminary131 file, using page 
##				images from Luminary 1A.
##		2016-12-14 RSB	Proofed text comments with octopus/ProoferComments
##				and corrected the errors found.
##		2017-08-01 MAS	Created from LMY99 Rev 1.

## 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.
##
## The code has been modified to match LMY99 Revision 0, otherwise
## known as Luminary Revision 99, the Apollo 11 software release preceeding
## the listing from which it was transcribed. It has been verified to
## contain the same bank checksums as AGC developer Allan Klumpp's listing
## of Luminary Revision 99 (for which we do not have scans).
##
## Notations on Allan Klumpp's listing read, in part:
##
##	ASSEMBLE REVISION 099 OF AGC PROGRAM LUMINARY BY NASA 2021112-51

## Page 490
		BANK	25
		SETLOC	RRLEADIN
		BANK
		
		EBANK=	RSTACK
		
# RADAR SAMPLING LOOP.

		COUNT*	$$/RLEAD
RADSAMP		CCS	RSAMPDT		# TIMES NORMAL ONCE-PER-SECOND SAMPLING.
		TCF	+2
		TCF	TASKOVER	# +0 INSERTED MANUALLY TERMINATES TEST.
		
		TC	WAITLIST
		EBANK=	RSTACK
		2CADR	RADSAMP
		
		CAF	PRIO25
		TC	NOVAC
		EBANK=	RSTACK
		2CADR	DORSAMP
		
		CAF	BIT14		# FOR CYCLIC SAMPLING, RTSTDEX=
		EXTEND			# RTSTLOC/2 + RTSTBASE
		MP	RTSTLOC
		AD	RTSTBASE	# 0 FOR RR, 2 FOR LR.
		TS	RTSTDEX
		TCF	TASKOVER
		
# DO THE ACTUAL RADAR SAMPLE.

DORSAMP		TC	VARADAR		# SELECTS VARIABLE RADAR CHANNEL.
		TC	BANKCALL
		CADR	RADSTALL
		
		INCR	RFAILCNT	# ADVANCE FAIL COUNTER BUT ACCEPT BAD DATA
		
DORSAMP2	INHINT
		CA	FLAGWRD5	# DON'T UPDATE RSTACK IF IN R77.
		MASK	R77FLBIT
		CCS	A
		TCF	+4
		
		DXCH	SAMPLSUM
		INDEX	RTSTLOC
		DXCH	RSTACK
		
		CS	RTSTLOC		# CYCLE RTSTLOC.
		AD	RTSTMAX
		EXTEND
		
## Page 491		
		BZF	+3
		CA	RTSTLOC
		AD	TWO		# STORAGE IS DP
		TS	RTSTLOC
		TCF	ENDOFJOB	# CONTINUOUS SAMPLING AND 2N TRIES - GONE.
		
# VARIABLE RADAR DATA CALLER FOR ONE MEASUREMENT ONLY.

VARADAR		CAF	ONE		# WILL BE SENT TO RADAR ROUTINE IN A BY
		TS	BUF2		# SWCALL.
		INDEX	RTSTDEX
		CAF	RDRLOCS
		TCF	SWCALL		# NOT TOUCHING Q.
		
RDRLOCS		CADR	RRRANGE		# = 0
		CADR	RRRDOT		# = 1
		CADR	LRVELX		# = 2
		CADR	LRVELY		# = 3
		CADR	LRVELZ		# = 4
		CADR	LRALT		# = 5