Revision 89c80bbe7f1b5318acd17f0dd4725105c41a12b3 authored by Ron Burkey on 22 March 2021, 22:44:22 UTC, committed by Ron Burkey on 22 March 2021, 22:44:22 UTC
1 parent 27501a8
SPS_BACK-UP_RCS_CONTROL.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: SPS_BACK-UP_RCS_CONTROL.agc
## Purpose: A section of the reconstructed source code for Luminary 130.
## This was the original program released for the Apollo 13 LM,
## although several more revisions would follow. It has been
## reconstructed from a listing of Luminary 131, from which it
## differs on only two lines in P70-P71. The difference is
## described in detail in Luminary memo #129, which was used
## to perform the reconstruction. This file is intended to be a
## faithful reconstruction, 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. 1499-1502
## Contact: Ron Burkey <info@sandroid.org>.
## Website: www.ibiblio.org/apollo/index.html
## Mod history: 06/08/03 RSB. Began transcribing.
## 05/14/05 RSB Corrected website reference above.
## 2010-10-25 JL Indentation fixes.
## 2017-01-06 RSB Page numbers now agree with those on the
## original hardcopy, as opposed to the PDF page
## numbers in 1701.pdf.
## 2017-02-28 RSB Proofed comment text using octopus/ProoferComments.
## 2017-03-14 RSB Comment-text fixes noted in proofing Luminary 116.
## 2018-09-04 MAS Copied from Luminary 131 for Luminary 130.
## Page 1499
# PROGRAM NAME: SPSRCS
# AUTHOR: EDGAR M. OSHIKA (AC ELECTRONICS)
# MODIFIED: TO RETURN TO ALL AXES VIA Q BY P. S. WEISSMAN, OCT 7, 1968
# MODIFIED TO IMPROVE BENDING STABILITY BY G. KALAN, FEB. 14, 1969
#
# FUNCTIONAL DESCRIPTION:
# THIS PROGRAM CONTROLS THE FIRING OF ALL RCS JETS IN THE DOCKED CONFIGURATION ACCORDING TO THE FOLLOWING PHASE
# PLANE LOGIC.
#
# 1. JET SENSE TEST (SPSRCS)
# IF JETS ARE FIRING NEGATIVELY, SET OLDSENSE NEGATIVE AND CONTINUE
# IF JETS ARE FIRING POSITIVELY, SET OLDSENSE POSITIVE AND CONTINUE
# IF JETS ARE NOT FIRING, SET OLDSENSE TO ZERO AND GO TO OUTER RATE LIMIT TEST
#
# 2. RATE DEAD BAND TEST
# IF JETS ARE FIRING NEGATIVELY AND RATE IS GREATER THAN TARGET RATE, LEAVE
# JETS ON AND GO TO INHIBITION LOGIC. OTHERWISE, CONTINUE.
# IF JETS ARE FIRING POSITIVELY AND RATE IS LESS THAN TARGET RATE, LEAVE
# JETS ON AND GO TO INHIBITION LOGIC. OTHERWISE, CONTINUE.
#
# 3. OUTER RATE LIMIT TEST (SPSSTART)
# IF MAGNITUDE OF EDOT IS GREATER THAN 1.73 DEG/SEC SET JET FIRING TIME
# TO REDUCE RATE AND GO TO INHIBITION LOGIC. OTHERWISE, CONTINUE.
#
# 4. COAST ZONE TEST
# IF STATE (E,EDOT) IS BELOW LINE E + 4 X EDOT > -1.4 DEG AND EDOT IS LESS THAN 1.30 DEG/SEC SET JET TIME POSI-
# TIVE AND CONTINUE. OTHERWISE, SET JET FIRING TIME TO ZERO AND CONTINUE.
# IF STATE IS ABOVE LINE E + 4 X EDOT > +1.4 DEG AND EDOT IS GREATER THAN -1.30 DEG/SEC, SET JET TIME NEGATIVE
# AND CONTINUE. OTHERWISE, SET JET FIRING TIME TO ZERO AND CONTINUE.
#
# 5. INHIBITION LOGIC
# IF OLDSENSE IS NON-ZERO:
# A) RETURN IF JET TIME HAS SAME SIGN AS OLDSENSE
# B) SET INHIBITION COUNTER* AND RETURN IF JET TIME IS ZERO
# C) SET INHIBITION COUNTER,* SET JET TIME TO ZERO AND RETURN IF SIGN
# OF JET TIME IS OPPOSITE TO THAT OF OLDSENSE
# IF OLDSENSE IS ZERO:
# A) RETURN IF INHIBITION COUNTER IS NOT POSITIVE
# B) SET JET TIME TO ZERO AND RETURN IF INHIBITION COUNTER IS POSITIVE
# *NOTE: INHIBITION COUNTERS CAN BE SET TO 4 OR 10 FOR THE P,AND UV AXES,
# RESPECTIVELY, IN SPSRCS. THEY ARE DECREMENTED BY ONE AT THE BEGINNING OF
## Page 1500
# EACH DAP PASS.
#
# THE MINIMUM PULSE WIDTH OF THIS CONTROLLER IS DETERMINED BY THE REPETITION RATE AT WHICH THIS ROUTINE IS CALLED
# AND IS NOMINALLY 100 MS FOR ALL AXES IN DRIFTING FLIGHT. DURING POWERED FLIGHT THE MINIMUM IS 100 MS FOR THE
# P AXIS AND 200 MS FOR THE CONTROL OF THE U AND V AXES.
#
# CALLING SEQUENCE:
# INHINT
# TC IBNKCALL
# CADR SPSRCS
#
# EXIT:
# TC Q
#
# ALARM/ABORT MODE: NONE
#
# SUBROUTINES CALLED: NONE
#
# INPUT: E, EDOT
# TJP, TJV, TJU TJ MUST NOT BE NEGATIVE ZERO
#
# OUTPUT: TJP, TJV, TJU
BANK 21
SETLOC DAPS4
BANK
COUNT* $$/DAPBU
EBANK= TJU
RATELIM2 OCT 00632 # 1.125 DEG/SEC
POSTHRST CA HALF
NDX AXISCTR
TS TJU
CCS OLDSENSE
TCF POSCHECK # JETS FIRING POSITIVELY
TCF CTRCHECK # JETS OFF. CHECK INHIBITION CTR
NEGCHECK INDEX AXISCTR # JETS FIRING NEGATIVELY
CS TJU
CCS A
TC Q # RETURN
TCF +2
TCF +1 # JETS COMMANDED OFF. SET CTR AND RETURN
SETCTR INDEX AXISCTR # JET FIRING REVERSAL COMMANDED. SET CTR,
CA UTIME # SET JET TIME TO ZERO,AND RETURN
## Page 1501
INDEX AXISCTR
TS UJETCTR
ZAPTJ CA ZERO
INDEX AXISCTR
TS TJU
TC Q
POSCHECK INDEX AXISCTR
CA TJU
TCF NEGCHECK +2
CTRCHECK INDEX AXISCTR # CHECK JET INHIBITION COUNTER
CCS UJETCTR
TCF +2
TC Q # CTR IS NOT POSITIVE. RETURN
TCF ZAPTJ # CTR IS POSITIVE. INHIBIT FIRINGS
TC Q # CTR IS NOT POSITIVE. RETURN
OCT 00004
UTIME OCT 00012
OCT 00012
OLDSENSE EQUALS DAPTREG1
NEGFIRE CS ONE # JETS FIRING NEGATIVELY
TS OLDSENSE
CA EDOT
TCF +4
PLUSFIRE CA ONE
TS OLDSENSE
CS EDOT # RATE DEAD BAND TEST
LXCH A
CS DAPBOOLS # IF DRIFTBIT = 1, USE ZERO TARGET RATE
MASK DRIFTBIT # IF DRIFTBIT = 0, USE 0.10 RATE TARGET
CCS A
CA RATEDB1
AD L
EXTEND
BZMF SPSSTART
TCF POSTHRST +3
SPSRCS INDEX AXISCTR # JET SENSE TEST
CCS TJU
TCF PLUSFIRE # JETS FIRING POSITIVELY
TCF +2
TCF NEGFIRE # JETS FIRING NEGATIVELY
TS OLDSENSE # JETS OFF
SPSSTART CA EDOT # OUTER RATE LIMIT TEST
EXTEND
MP RATELIM1
CCS A
TCF NEGTHRST # OUTER RATE LIMIT EXCEEDED
TCF +2
TCF POSTHRST # OUTER RATE LIMIT EXCEEDED
CA EDOT # COAST ZONE TEST
## Page 1502
AD E
EXTEND
MP DKDB # PAD LOADED DEADBAND. FRESHSTART: 1.4 DEG
EXTEND
BZF TJZERO
EXTEND
BZMF +7
CA EDOT
AD RATELIM2
EXTEND
BZMF TJZERO
NEGTHRST CS HALF
TCF POSTHRST +1
+7 CS RATELIM2
AD EDOT
EXTEND
BZMF POSTHRST
TJZERO CA ZERO
TCF POSTHRST +1
RATELIM1 = CALLCODE # = 00032, CORRESPONDING TO 1.73 DEG/SEC
RATEDB1 = TBUILDFX # = 00045, CORRESPONDS TO 0.101 DEG/SEC
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