R31.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: R31.agc
## Purpose: A section of Luminary revision 173.
## It is part of the reconstructed source code for the second
## (unflown) release of the flight software for the Lunar
## Module's (LM) Apollo Guidance Computer (AGC) for Apollo 14.
## The code has been recreated from a reconstructed copy of
## Luminary 178, as well as Luminary memo 167 (revision 1).
## It has been adapted such that the resulting bugger words
## exactly match those specified for Luminary 173 in NASA
## drawing 2021152N, which gives relatively high confidence
## that the reconstruction is correct.
## Reference: pp. 698-702
## Assembler: yaYUL
## Contact: Ron Burkey <info@sandroid.org>.
## Website: www.ibiblio.org/apollo/index.html
## Mod history: 2019-09-18 MAS Created from Luminary 178.
## Page 698
BANK 40
SETLOC R31LOC
BANK
COUNT* $$/R31
R31CALL CAF PRIO3
TC FINDVAC
EBANK= SUBEXIT
2CADR V83CALL
DSPDELAY TC FIXDELAY
DEC 100
CA EXTVBACT
MASK BIT12
EXTEND
BZF DSPDELAY
CAF PRIO5
TC NOVAC
EBANK= TSTRT
2CADR DISPN5X
TCF TASKOVER
V16N54 VN 1654
DISPN5X CAF V16N54
TC BANKCALL
CADR GOMARKF
TC B5OFF
TC B5OFF
TCF DISPN5X
BANK 37
SETLOC R31
BANK
V83CALL CS FLAGWRD7 # TEST AVERAGE G FLAG
MASK AVEGFBIT
EXTEND
BZF MUNG? # ON - TEST MUNFLAG
CS FLAGWRD8
MASK SURFFBIT
EXTEND
BZF ONEBASE # ON SURFACE - BYPASS LEMPREC
TC INTPRET # EXTRAPOLATE BOTH STATE VECTORS
RTB
## Page 699
LOADTIME
STCALL TDEC1
LEMPREC # PRECISION BASE VECTOR FOR LM
VLOAD
RATT1
STOVL BASETHP
VATT1
STODL BASETHV
TAT
DOCMBASE STORE BASETIME # PRECISION BASE VECTOR FOR CM
STCALL TDEC1
CSMPREC
VLOAD
RATT1
STOVL BASEOTP
VATT1
STORE BASEOTV
EXIT
REV83 CS FLAGWRD7
MASK AVEGFBIT
EXTEND
BZF GETRVN # IF AVEGFLAG SET, USE RN,VN
CS FLAGWRD8
MASK SURFFBIT
EXTEND
BZF R31SURF # IF ON SURFACE,USE LEMAREC
TC INTPRET # DO CONIC EXTRAPOLATION FOR BOTH VEHICLES
RTB
LOADTIME
STCALL TDEC1
INTSTALL
VLOAD CLEAR
BASETHP
MOONFLAG
STOVL RCV
BASETHV
STODL VCV
BASETIME
BOF SET # GET APPROPRIATE MOONFLAG SETTING
MOONTHIS
+2
MOONFLAG
SET
INTYPFLG # CONIC EXTRAP.
STCALL TET
INTEGRVS # INTEGRATION --- AT LAST---
OTHCONIC VLOAD
## Page 700
RATT
STOVL RONE
VATT
STCALL VONE # GET SET FOR CONIC EXTRAP.,OTHER.
INTSTALL
SET DLOAD
INTYPFLG
TAT
OTHINT STORE TDEC1
VLOAD CLEAR
BASEOTP
MOONFLAG
STOVL RCV
BASEOTV
STODL VCV
BASETIME
BOF SET
MOONTHIS
+2
MOONFLAG
STCALL TET
INTEGRVS
COMPDISP VLOAD VSU
RATT
RONE
RTB PDDL
NORMUNX1 # UNIT(RANGE) TO PD 0-5
36D
SL* # RESCALE AFTER NORMUNIT
0,1
STOVL RANGE # SCALED 2(29)M
VATT
VSU DOT # (VCM- VLM).UNIT(LOS), PD=0
VONE
SL1 # SCALED 2(7)M/CS
STOVL RRATE
RONE
UNIT PDVL # UNIT(R) TO PD 0-5
UNITZ
CALL
CDU*NBSM
VXM PUSH # UNIT (Z)/4 TO PD 6-11
REFSMMAT
VPROJ VSL2 # UNIT(P)=UNIT(UZ -(UZ)PROJ(UR))
0D
BVSU UNIT
6D
PDVL VXV # UNIT(P) TO PD 12-17
0D # UNIT(RL)
VONE
## Page 701
VXV DOT # (UR * VL)*UR . U(P)
0D
12D
PDVL # SIGN TO 12-13 , LOAD U(P)
DOT SIGN
6D
12D
SL2 ACOS # ARCCOS(UP.UZ(SIGN))
STOVL RTHETA
0D
DOT BPL # IF UR.UZ NEG,
6D # RTHETA = 1 - RTHETA
+5
DLOAD DSU
DPPOSMAX
RTHETA
STORE RTHETA
EXIT
CA BIT5
MASK EXTVBACT
EXTEND # IF ANSWERED,
BZF ENDEXT # TERMINATE
CS EXTVBACT
MASK BIT12
ADS EXTVBACT # SET BIT 12
TCF REV83 # AND START AGAIN.
GETRVN CA PRIO22 # INHIBIT SERVICER
TC PRIOCHNG
TC INTPRET
VLOAD SETPD
RN # LM STATE VECTOR IN RN,VN
0
STOVL RONE
VN
STOVL VONE # LOAD R(CSM),V(CSM) IN CASE MUNFLAG SET
V(CSM) # (TO INSURE TIME COMPATABILITY)
PDVL PDDL
R(CSM)
PIPTIME
EXIT
CA PRIO3
TC PRIOCHNG
TC INTPRET
BOFF VLOAD
MUNFLAG
GETRVN2 # IF MUNFLAG RESET, DO CM DELTA PRECISION
## Page 702
VXM VSR4 # CHANGE TO REFERENCE SYSTEM AND RESCALE
REFSMMAT
PDVL # R TO PD 0-5
VXM VSL1
REFSMMAT
PUSH SETPD # V TO PD 5-11
0
GOTO
COMPDISP
GETRVN2 CALL
INTSTALL
CLEAR GOTO
INTYPFLG # PREC EXTRAP FOR OTHER
OTHINT
R31SURF TC INTPRET
RTB # LM IS ON SURFACE, SO PRECISION
LOADTIME # INTEGRATION USES PLANETARY INERTIAL
STCALL TDEC1 # ORIENTATION SUBROUTINE
LEMPREC
GOTO # DO CSM CONIC
OTHCONIC
MUNG? CS FLAGWRD6
MASK MUNFLBIT
EXTEND
BZF GETRVN # IF MUNFLAG SET, CSM BASE NOT NEEDED
ONEBASE TC INTPRET # GET CSM BASE VECTOR
RTB GOTO
LOADTIME
DOCMBASE
