https://github.com/virtualagc/virtualagc
Revision 078c79d8734a9ed2860303a7c1662004284fe853 authored by Ron Burkey on 07 August 2022, 15:04:04 UTC, committed by Ron Burkey on 07 August 2022, 15:04:04 UTC
assembly listings from yaASM and yaLEMAP. Added some debugging messages to 'make install'. Tweaked debugging messages that VirtualAGC embeds in 'simulate'. Verified buildability in Mint 21, 20, 19, 17, and verified buildability using clang in Mint 17.
1 parent 6bb1acc
Tip revision: 078c79d8734a9ed2860303a7c1662004284fe853 authored by Ron Burkey on 07 August 2022, 15:04:04 UTC
Fixed a potential string-overflow bug in yaASM. Removed timestamps from
Fixed a potential string-overflow bug in yaASM. Removed timestamps from
Tip revision: 078c79d
LATITUDE_LONGITUDE_SUBROUTINES.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: LATITUDE_LONGITUDE_SUBROUTINES.agc
## Purpose: A section of LUM69 revision 2.
## It is part of the reconstructed source code for the flown
## version of the flight software for the Lunar Module's (LM)
## Apollo Guidance Computer (AGC) for Apollo 10. The code has
## been recreated from a copy of Luminary revsion 069, using
## changes present in Luminary 099 which were described in
## Luminary memos 75 and 78. The code has been adapted such
## that the resulting bugger words exactly match those specified
## for LUM69 revision 2 in NASA drawing 2021152B, which gives
## relatively high confidence that the reconstruction is correct.
## Reference: pp. 1128-1134
## Assembler: yaYUL
## Contact: Ron Burkey <info@sandroid.org>.
## Website: www.ibiblio.org/apollo/index.html
## Mod history: 2019-07-27 MAS Created from Luminary 69.
## Page 1128
# SUBROUTINE TO CONVERT RAD VECTOR AT GIVEN TIME TO LAT,LONG AND ALT
#
# CALLING SEQUENCE
# L-1 CALL
# L LAT-LONG
#
# SUBROUTINES USED
# R-TO-RP,ARCTAN,SETGAMMA,SETRE
#
# ERASABLE INIT. REQ.
# AXO,-AYO,AZO,TEPHEM (SET AT LAUNCH TIME)
# ALPHAV = POSITION VECTOR METERS B-29
# MPAC-- TIME (CSECS B-28)
# ERADFLAG =1, TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
# LUNAFLAG=0 FOR EARTH, 1 FOR MOON
#
# OUTPUT
# LATITUDE IN LAT (REVS. B-0)
# LONGITUDE IN LONG (REVS. B-0)
# ALTITUDE IN ALT METERS B-29
BANK 30
SETLOC LATLONG
BANK
COUNT* $$/LT-LG
EBANK= ALPHAV
LAT-LONG STQ SETPD
INCORPEX
0D
STOVL 6D # SAVE TIME IN 6-7D FOR R-TO-RP
ALPHAV
PUSH ABVAL # 0-5D= R FOR R-TO-RP
STODL ALPHAM # ABS. VALUE OF R FOR ALT FORMULA BELOW
ZEROVEC # SET MPAC=0 FOR EARTH, NON-ZERO FOR MOON
BOFF COS # USE COS(0) TO GET NON-ZERO IN MPAC
LUNAFLAG # 0=EARTH, 1=MOON
CALLRTRP
CALLRTRP CALL
R-TO-RP # RP VECTOR CONVERTED FROM R B-29
UNIT # UNIT RP B-1
STCALL ALPHAV # U2= 1/2 SINL FOR SETRE SUBR BELOW
SETGAMMA # SET GAMMA=B2/A2 FOR EARTH,=1 FOR MOON
CALL # SCALED B-1
SETRE # CALC RE METERS B-29
DLOAD DSQ
ALPHAV
PDDL DSQ
ALPHAV +2
DAD SQRT
## Page 1129
DMP SL1R
GAMRP
STODL COSTH # COS(LAT) B-1
ALPHAV +4
STCALL SINTH # SIN(LAT) B-1
ARCTAN
STODL LAT # LAT B0
ALPHAV
STODL COSTH # COS(LONG) B-1
ALPHAV +2
STCALL SINTH # SIN(LONG) B-1
ARCTAN
STODL LONG # LONG. REVS B-0 IN RANGE -1/2 TO 1/2
ALPHAM
DSU # ALT= R-RE METERS B-29
ERADM
STCALL ALT # EXIT WITH ALT METERS B-29
INCORPEX
## Page 1130
# SUBROUTINE TO CONVERT LAT,LONG,ALT AT GIVEN TIME TO RADIUS VECTOR
#
# CALLING SEQUENCE
# L-1 CALL
# L LALOTORV
#
# SUBROUTINES USED
# SETGAMMA,SETRE,RP-TO-R
#
# ERASABLE INIT. REQ.
# AXO,AYO,AZO,TEPHEM SET AT LAUNCH TIME
# LAT-- LATITUDE (REVS B0)
# LONG-- LONGITUDE (REVS B0)
# ALT--ALTITUDE (METERS) B-29
# MPAC-- TIME (CSECS B-28)
# ERADFLAG =1 TO COMPUTE EARTH RADIUS, =0 FOR FIXED EARTH RADIUS
# LUNAFLAG=0 FOR EARTH, 1 FOR MOON
#
# OUTPUT
# R-VECTOR IN ALPHAV (METERS B-29)
LALOTORV STQ SETPD # LAT,LONG,ALT TO R VECTOR
INCORPEX
0D
STCALL 6D # 6-7D= TIME FOR RP-TO-R
SETGAMMA # GAMMA=B2/A2 FOR EARTH,1 FOR MOON B-1
DLOAD SIN # COS(LONG)COS(LAT) IN MPAC
LAT # UNIT RP= SIN(LONG)COS(LAT) 2-3D
DMPR PDDL # PD 2 GAMMA*SIN(LAT) 0-1D
GAMRP
LAT # 0-1D= GAMMA*SIN(LAT) B-2
COS PDDL # PD 4 2-3D=COS(LAT) B-1 TEMPORARILY
LONG
SIN DMPR # PD 2
PDDL COS # PD 4 2-3D=SIN(LONG)COS(LAT) B-2
LAT
PDDL COS # PD 6 4-5D=COS(LAT) B-1 TEMPORARILY
LONG
DMPR VDEF # PD 4 MPAC= COS(LONG)COS(LAT) B-2
UNIT PUSH # 0-5D= UNIT RP FOR RP-TO-R SUBR.
STCALL ALPHAV # ALPHAV +4= SINL FOR SETRE SUBR.
SETRE # RE METERS B-29
DLOAD BOFF # SET MPAC=0 FOR EARTH, NON-ZERO FOR MOON
ZEROVEC
LUNAFLAG
CALLRPRT
COS # USE COS(0) TO GET NON-ZERO IN MPAC
CALLRPRT CALL
RP-TO-R # EXIT WITH UNIT R VECTOR IN MPAC
STODL ALPHAV
ERADM
## Page 1131
DAD VXSC # (RE + ALT)(UNIT R) METERS B-30
ALT
ALPHAV
VSL1 # R METERS B-29
STCALL ALPHAV # EXIT WITH R IN METERS B-29
INCORPEX
# SUBROUTINE TO COMPUTE EARTH RADIUS
#
# INPUT
# 1/2 SIN LAT IN ALPHAV +4
#
# OUTPUT
# EARTH RADIUS IN ERADM AND MPAC (METERS B-29)
GETERAD DLOAD DSQ
ALPHAV +4 # SIN**2(L)
SL1 BDSU
DP1/2 # COS**2(L)
DMPR BDSU
EE
DP1/2
BDDV SQRT
B2XSC
SR4R
STORE ERADM
RVQ
# THE FOLLOWING CONSTANTS WERE COMPUTED WITH A=6378166, B=6356784 METERS
# B2XSC= B**2 SCALED B-51
# B2/A2= B**2/A**2 SCALED B-1
# EE=(1-B**2/A**2) SCALED B-0
B2XSC 2DEC .0179450689 # B**2 SCALED B-51
DP1/2 = XUNIT
B2/A2 2DEC .9933064884 B-1 # GAMMA= B**2/A**2 B-1
EE 2DEC 6.6935116 E-3 # (1-B**2/A**2) B-0
## Page 1132
# ARCTAN SUBROUTINE
#
# CALLING SEQUENCE
# SIN THETA IN SINTH B-1
# COS THETA IN COSTH B-1
# CALL ARCTAN
#
# OUTPUT
# ARCTAN THETA IN MPAC AND THETA B-0 IN RANGE -1/2 TO +1/2
ARCTAN BOV
CLROVFLW
CLROVFLW DLOAD DSQ
SINTH
PDDL DSQ
COSTH
DAD
BZE SQRT
ARCTANXX # ATAN=0/0 SET THETA=0
BDDV BOV
SINTH
ATAN=90
SR1 ASIN
STORE THETA
PDDL BMN
COSTH
NEGCOS
DLOAD RVQ
NEGCOS DLOAD DCOMP
BPL DAD
NEGOUT
DP1/2
ARCTANXX STORE THETA
RVQ
NEGOUT DSU GOTO
DP1/2
ARCTANXX
ATAN=90 DLOAD SIGN
LODP1/4
SINTH
STORE THETA
RVQ
2DZERO = DPZERO
## Page 1133
# ..... SETGAMMA SUBROUTINE .....
# SUBROUTINE TO SET GAMMA FOR THE LAT-LONG AND LALOTORV SUBROUTINES
#
# GAMMA = B**2/A**2 FOR EARTH (B-1)
# GAMMA = 1 FOR MOON (B-1)
#
# CALLING SEQUENCE
# L CALL
# L+1 SETGAMMA
#
# INPUT
# LUNAFLAG=0 FOR EARTH,=1 FOR MOON
#
# OUTPUT
# GAMMA IN GAMRP (B-1)
SETGAMMA DLOAD BOFF # BRANCH FOR EARTH
B2/A2 # EARTH GAMMA
LUNAFLAG
SETGMEX
SLOAD
1B1 # MOON GAMMA
SETGMEX STORE GAMRP
RVQ
GAMRP = 8D
## Page 1134
# ..... SETRE SUBROUTINE .....
# SUBROUTINE TO SET RE (EARTH OR MOON RADIUS)
#
# RE= RM FOR MOON
# RE= RREF FOR FIXED EARTH RADIUS OR COMPUTED RF FOR FISCHER ELLIPSOID
#
# CALLING SEQUENCE
# L CALL
# L+1 SETRE
#
# SUBROUTINES USED
# GETERAD
#
# INPUT
# ERADFLAG=0 FOR FIXED RE, 1 FOR COMPUTED RE
# ALPHAV +4= 1/2 SINL IF GETERAD IS CALLED
# LUNAFLAG=0 FOR EARTH,=1 FOR MOON
#
# OUTPUT
# ERADM= 504RM FOR MOON (METERS B-29)
# ERADM= ERAD OR COMPUTED RF FOR EARTH (METERS B-29)
SETRE STQ DLOAD
SETREX
504RM
BON DLOAD # BRANCH FOR MOON
LUNAFLAG
TSTRLSRM
ERAD
BOFF CALL # ERADFLAG=0 FOR FIXED RE, 1 FOR COMPUTED
ERADFLAG
SETRXX
GETERAD
SETRXX STCALL ERADM # EXIT WITH RE OR RM METERS B-29
SETREX
TSTRLSRM BON VLOAD # ERADFLAG=0, SET R0=RLS
ERADFLAG # =1 R0=RM
SETRXX
RLS
ABVAL SR2R # SCALE FROM B-27 TO B-29
GOTO
SETRXX
SETREX = S2
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