TVCGEN3FILTERS.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: TVCGEN3FILTERS.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. 961
## Contact: Ron Burkey <info@sandroid.org>.
## Website: www.ibiblio.org/apollo/index.html
## Mod history: 08/24/04 RSB. Began transcribing.
## 05/14/05 RSB Corrected website references above.
## 2010-10-25 JL Fixed page numbers.
## 2017-01-06 RSB Page numbers now agree with those on the
## original harcopy, as opposed to the PDF page
## numbers in 1701.pdf.
## 2017-01-20 RSB Cross-diff'd comment text (not whitespace)
## vs the already-proofed corresponding Colossus
## 237 source-code files, and corrected 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 961
# PROGRAM NAME.... GEN3DAP FILTERS, CONSISTING OF NP0NODE, NP1NODE, NY0NODE, NY1NODE, ETC.
# LOG SECTION.... GEN3DAP FILTERS SUBROUTINE....DAPCSM
# MOD BY ENGEL 20 OCT, 1967
#
# FUNCTIONAL DESCRIPTION....
#
# THE GEN3DAP FILTER PACKAGE IS DESIGNED TO PROVIDE FLEXIBLE, LAST-MINUTE CHANGEABLE DIGITAL AUTOPILOT
# FILTERS FOR LEM-OFF FLIGHT. GROUNDRULES FOR THE DESIGN AND USE OF THE PACKAGE ARE AS FOLLOWS.....
#
# 1. FILTER COEFFICIENTS AND GAINS IN ERASABLE MEMORY
# 2. UP TO THIRD-ORDER NUMERATOR OR DENOMINATOR
# 3. OPERATIONAL FIT WITHIN THE STRUCTURE OF THE REGULAR LEM-ON DAP CODING
# 4. DENOMINATOR POLES INSIDE THE Z-PLANE UNIT CIRCLE
# 5. NUMERATOR ZEROS INSIDE THE Z-PLANE DOUBLE-UNIT CIRCLE
# 6. HIGH FREQUENCY (BODE) GAIN LESS THAN 8ASCREVS, OR 8.6380088 DEG/DEG
#
# THE FILTERS ARE SHOWN IN THE FOLLOWING DIAGRAMS.....
# PITCH GEN3DAP FILTER..
# KPGEN3
# ********
# ***************************************** *
# * * *
# * -1 -2 -3 * *
# EP = ERRBTMP * APO + AP1 Z + AP2 Z + AP3 Z * NPO NPD = CMDTMP **
# *************** ----------------------------------- **********( X )*********************
# * -1 -2 -3 * **
# * 1 + BP1 Z + BP2 Z + BP3 Z *
# * *
# *****************************************
#
# YAW GEN3DAP FILTER..
# KYGEN3
# ********
# ***************************************** *
# * * *
# * -1 -2 -3 * *
# EY = ERRBTMP * AYO + AY1 Z + AY2 Z + AY3 Z * NY0 NYP = CMDTMP **
# *************** ----------------------------------- **********( X )*********************
# * -1 -2 -3 * **
# * 1 + BY1 Z + BY2 Z + BY3 Z *
# * *
# *****************************************
#
## Page 962
# THE IMPLEMENTING EQUATIONS FOR THESE FILTERS ARE AS FOLLOWS.....
#
# PITCH GEN3DAP.... YAW GEN3DAP....
# NPD = (B+4) KPGEN3 NP0 NYD = (B+4) KYGEN3 NY0
# NP0 = AP0 EP + 4(Z-1) NP1 NY0 = AY0 EY + 4(Z-1) NY1
# NY1 = AP1 EP - BP1 NP0 + (Z-1) NP2 NY1 = AY1 EY - BY1 NY0 + (Z-1) NY2
# NP2 = AP2 EP - BP2 NP0 + (Z-1) NP3 NY2 = AY2 EY - BY2 NY0 + (Z-1) NY3
# NP3 = AP3 EP - BP3 NP0 NY3 = AY3 EY - BY3 NY0
#
# FILTER INPUTS EP AND EY ARE PICKED UP FROM REGULAR LEM-ON CODING AT ERRBTMP (UPPER WORD ONLY), THUS ARE
# SINGLE PRECISION QUANTITIES SCALED AT B-1 REVS. FILTER OUTPUTS NPD AND NYD ARE LEFT IN DOUBLE PRECISION AT
# CMDTMP, SCALED AT 1 ASCREV, READY FOR OUTPUT PROCESSING VIA REGULAR LEM-ON CODING AT ..P,YOFFSET..
# FOLLOWING OUTPUT PROCESSING, RETURN TO THE GEN3DAP FILTERS IS MADE FOR CALCULATION OF THE REMAINING NODES
# NP1 TO NP3, OR NY1 TO NY3. GEN3DAP FILTERS THEN RETURN TOTHE LEM-ON CODING AT ..DELBARP,Y.. FOR RESPECTIVE
# OFFSET-TRACKER-FILTER COMPUTATIONS AND COPYCYCLES. NOTE THE EQUIVALENCES...NP1TMP=J5TMP, NP1=J5,
# NP2TMP=NSUMTMP, NP2=PNSUM, NP3TMP=DSUMTMP, NP3=PDSUM, WITH CORRESPONDING RELATIONS FOR YAW. THUS THE COPY-
# CYCLE PCOPY, FROM THE GEN3DAP STANDPOINT, IS EFFECTIVE FROM PMISC-3 TO ITS END AT TC Q. YCOPY FROM YMISC-3.
# SCALING OF THE FILTER NODES, COEFFICIENTS, AND GAINS WITHIN THE AGC IS AS FOLLOWS.....
#
# QUANTITY QUANTITY PHYS. UNITS MAX. VALUE SCALE AT (FOR)
#
# EP EY REVS 1/8 B-1 REV (CDU SCALING)
#
# NP0 NY0 REVS (B+1) B+1 REV
# NP1 NY1 REVS (B+3) B+3 REV
# NP2 NY2 REVS (B+3) B+3 REV
# NP3 NY3 REVS (B+3) B+3 REV
#
# NPD NYD ASC REVS (1) 1 ASCREV (ACTUATOR CDU SCALING)
#
# KPGEN3 KYGEN3 ASCREV/REV (8) B+3 ASCREV/REV
#
# AP0 AY0 DIMLESS. 1 B+2
# AP1 AY1 DIMLESS. 6 B+4
# AP2 AY2 DIMLESS. 12 B+4
# AP3 AY3 DIMLESS. 8 B+4
#
# BP1 BY1 DIMLESS. 3 B+2
# BP2 BY2 DIMLESS. 3 B+2
# BP3 BY3 DIMLESS. 1 B+2
#
# FILTER COEFFICIENTS, GAINS, AND NODES ARE HELD IN DOUBLE PRECISION (ERASABLE) TO PERMIT CONSERVATIVE
# SCALING AND YET OFFSET TRUNCATION LOSSES. THIS APPEARS NECESSARY IF FILTER FLEXIBILITY IS TO BE MAINTAINED.
# COMPUTATION TIME IS NOT CRITICAL.
#
## Page 963
# CALLING SEQUENCE....
#
# *TC POSTJUMP....
# CADR NP0NODE, NP1, NY0, NY1. SPECIFICALLY, FROM PITCHDAP OR YAWDAP
# (TVCDAP), AT P1FILJMP, P2FILJMP, Y1FILJMP, Y2FILJMP
#
# NORMAL EXIT MODE....
#
# *TC POSTJUMP....
# CADR (POFFSET, DELBARP), (YOFFSET, DELBARY). IE, RETURNS TO
# PITCHDAP OR YAWDAP AT APPROPRIATE ENTRY POINT
#
# ALARM OR ABORT EXIT MODES....NONE
#
# SUBROUTINES CALLED.... NONE
#
# ERASABLE INITIALIZATION REQUIRED....
#
# *AP0(SP),AP1(DP),...AP3(DP), (PITCH AND YAW) NUMERATOR COEFFICIENTS
# (PAD LOADS)
#
# *BP1(DP),...BP3(DP), (PITCH AND YAW) DENOMINATOR COEFFICIENTS
# (PAD LOADS)
#
# *KPGEN3 (S40.15 OF R03)
#
# OUTPUT....
#
# *CMDTMP (NPD, NYD) FOR OUTPUT PROCESSING BY PITCHDAP OR YAWDAP
#
# *OTHER FILTER NODES
#
# DEBRIS....TVC TEMPORARIES, SHAREABLE WITH RCS/ENTRY IN EBANK6 ONLY
BANK 21
SETLOC DAPS4
BANK
EBANK= EP
COUNT* $$/GEN3
## Page 964
# PITCH GEN3DAP FILTER.....
NP0NODE EXTEND # FORM NODE NP0....COLLECT (PAST NP1)
DCA NP1 # (COMES HERE FROM REG. DAP CODING)
DDOUBL
DDOUBL
DXCH NP0
AP0(EP) CAE EP # SPXSP MULTIPLY FOR NUMERATOR COMPONENT
EXTEND # EP = ERRBTMP, SP, SC.AT B-1 REVS
MP AP0
DAS NP0 # COMPLETED NODE NP0, SC.AT B+1 REVS
NPDNODE CAE NP0 # FORM NODE NPD....SPXDP MULTIPLY BY GAIN
EXTEND
MP KPGEN3
DXCH NPD
CAE NP0 +1
EXTEND
MP KPGEN3
ZL
LXCH A
DAS NPD # SC.AT B+4 ASCREV SINCE KPGEN3 AT B+3
DXCH NPD # FIX UP SCALING
DDOUBL
DDOUBL
DDOUBL
DDOUBL
DXCH NPD # COMPLETED NODE NPD, SC.AT 1ASCREV
TC POSTJUMP # TRANSFER BACK TO REGULAR DAP CODING FOR
CADR POFFSET # OUTPUT (NPD = CMDTMP, DP)
NP1NODE EXTEND # FORM NODE NP1....COLLECT (PAST NP2)
DCA NP2 # (COMES HERE FROM REG. DAP CODING)
DXCH NP1TMP
BP1(NP0) CS NP0 # DPXDP MULTIPLY FOR DENOMINATOR COMPONENT
EXTEND
MP BP1
DAS NP1TMP
CS NP0 +1
EXTEND
MP BP1
ADS NP1TMP +1
TS L
TCF +2
ADS NP1TMP
## Page 965
CS NP0
EXTEND
MP BP1 +1
ADS NP1TMP +1
TS L
TCF +2
ADS NP1TMP
AP1(EP) CAE EP # DPXSP MULTIPLY FOR NUMERATOR COMPONENT
EXTEND
MP AP1
DAS NP1TMP
CAE EP
EXTEND
MP AP1 +1
ADS NP1TMP +1
TS L
TCF +2
ADS NP1TMP # COMPLETED NODE NP1
NP2NODE EXTEND # FORM NODE NP2....COLLECT (PAST NP3)
DCA NP3
DXCH NP2TMP
BP2(NP0) CS NP0 # DPXDP MULTIPLY FOR DENOMINATOR COMPONENT
EXTEND
MP BP2
DAS NP2TMP
CS NP0 +1
EXTEND
MP BP2
ADS NP2TMP +1
TS L
TCF +2
ADS NP2TMP
CS NP0
EXTEND
MP BP2 +1
ADS NP2TMP +1
TS L
TCF +2
ADS NP2TMP
AP2(EP) CAE EP # DPXSP MULTIPLY FOR NUMERATOR COMPONENT
EXTEND
MP AP2
DAS NP2TMP
CAE EP
EXTEND
MP AP2 +1
ADS NP2TMP +1
## Page 966
TS L
TCF +2
ADS NP2TMP # COMPLETED NODE NP2
NP3NODE CS NP0 # FORM NODE NP3....NO PAST NODES, DIRECT
EXTEND # TO DPXDP MULTIPLY FOR DENOMINATOR
MP BP3 # COMPONENT
DXCH NP3TMP
CS NP0 +1
EXTEND
MP BP3
ADS NP3TMP +1
TS L
TCF +2
ADS NP3TMP
CS NP0
EXTEND
MP BP3 +1
ADS NP3TMP +1
TS L
TCF +2
ADS NP3TMP
AP3(EP) CAE EP # DPXSP MULTIPLY FOR NUMERATOR COMPONENT
EXTEND
MP AP3
DAS NP3TMP
CAE EP
EXTEND
MP AP3 +1
ADS NP3TMP +1
TS L
TCF +2
ADS NP3TMP # COMPLETED NODE NP3, AND PITCH GEN3DAP
# FILTER COMPUTATIONS
TC POSTJUMP # RETURN TO CSMDAP CODING FOR PITCH
CADR DELBARP # OFFSET-TRACKER-FILTER COMPUTATIONS,
# AND PITCH DAP COPYCYCLE.
## Page 967
# YAW GEN3DAP FILTER....
NY0NODE EXTEND # FORM NODE NY0....COLLECT (PAST NY1)
DCA NY1 # (COMES HERE FROM REG. DAP CODING)
DDOUBL
DDOUBL
DXCH NY0
AY0(EY) CAE EY # SPXSP MULTIPLY FOR NUMERATOR COMPONENT
EXTEND # EY = ERRBTMP, SP, SC.AT B-1 REVS
MP AY0
DAS NY0 # COMPLETED NODE NY0, SC.AT B+1 REVS
NYDNODE CAE NY0 # FORM NODE NYD....SPXDP MULTIPLY BY GAIN
EXTEND
MP KYGEN3
DXCH NYD
CAE NY0 +1
EXTEND
MP KYGEN3
ZL
LXCH A
DAS NYD # SC.AT B+4 ASCREV SINCE KYGEN3 AT B+1
DXCH NYD # FIX UP SCALING
DDOUBL
DDOUBL
DDOUBL
DDOUBL
DXCH NYD # COMPLETED NODE NYD, SC.AT 1ASCREV
TC POSTJUMP # TRANSFER BACK TO REGULAR DAP CODING FOR
CADR YOFFSET # OUTPUT (NYD = CMDTMP, DP)
NY1NODE EXTEND # FORM NODE NY1....COLLECT (PAST NY2)
DCA NY2 # (COMES HERE FROM REG. DAP CODING)
DXCH NY1TMP
BY1(NY0) CS NY0 # DPXDP MULTIPLY FOR DENOMINATOR COMPONENT
EXTEND
MP BY1
DAS NY1TMP
CS NY0 +1
EXTEND
MP BY1
ADS NY1TMP +1
TS L
TCF +2
ADS NY1TMP
## Page 968
CS NY0
EXTEND
MP BY1 +1
ADS NY1TMP +1
TS L
TCF +2
ADS NY1TMP
AY1(EY) CAE EY # DPXSP MULTIPLY FOR NUMERATOR COMPONENT
EXTEND
MP AY1
DAS NY1TMP
CAE EY
EXTEND
MP AY1 +1
ADS NY1TMP +1
TS L
TCF +2
ADS NY1TMP # COMPLETED NODE NY1
NY2NODE EXTEND # DORM NODE NY2....COLLECT (PAST NY3)
DCA NY3
DXCH NY2TMP
BY2(NY0) CS NY0 # DPXDP MULTIPLY FOR DENOMINATOR COMPONENT
EXTEND
MP BY2
DAS NY2TMP
CS NY0 +1
EXTEND
MP BY2
ADS NY2TMP +1
TS L
TCF +2
ADS NY2TMP
CS NY0
EXTEND
MP BY2 +1
ADS NY2TMP +1
TS L
TCF +2
ADS NY2TMP
AY2(EY) CAE EY # DPXSP MULTIPLY FOR NUMERATOR COMPONENT
EXTEND
MP AY2
DAS NY2TMP
CAE EY
EXTEND
MP AY2 +1
## Page 969
ADS NY2TMP +1
TS L
TCF +2
ADS NY2TMP # COMPLETED NODE NY2
NY3NODE CS NY0 # FORM NODE NY3....NO PAST NODES, DIRECT
EXTEND # TO DPXDP MULTIPLY FOR DENOMINATOR
MP BY3 # COMPONENT
DXCH NY3TMP
CS NY0 +1
EXTEND
MP BY3
ADS NY3TMP +1
TS L
TCF +2
ADS NY3TMP
CS NY0
EXTEND
MP BY3 +1
ADS NY3TMP +1
TS L
TCF +2
ADS NY3TMP
AY3(EY) CAE EY # DPXSP MULTIPLY FOR NUMERATOR COMPONENT
EXTEND
MP AY3
DAS NY3TMP
CAE EY
EXTEND
MP AY3 +1
ADS NY3TMP +1
TS L
TCF +2
ADS NY3TMP # COMPLETED NODE NY3, AND YAW GEN3DAP
# FILTER COMPUTATIONS
TC POSTJUMP # RETURN TO CSMDAP CODING FOR YAW
CADR DELBARY # OFFSET-TRACKER-FILTER COMPUTATIONS,
# AND YAW DAP COPYCYCLE.
