R63.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: R63.agc
## Purpose: A section of Luminary revision 116.
## It is part of the source code for the Lunar Module's (LM)
## Apollo Guidance Computer (AGC) for Apollo 12.
## This file is intended to be a faithful transcription, 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. 339-342
## Assembler: yaYUL
## Contact: Ron Burkey <info@sandroid.org>.
## Website: www.ibiblio.org/apollo/index.html
## Mod history: 2017-01-22 MAS Created from Luminary 99.
## 2017-01-26 RSB Back-ported a comment-text fix from Luminary 69.
## Mod history: 2017-01-22 MAS Created from Luminary 99.
## 2017-03-07 RSB Transcribed, and then proofed comment-text using
## 3-way diff vs Luminary 99 and Luminary 131.
## (Admittedly, the former is more for detecting errors
## in Luminary 99 than the other way around.)
## Page 339
# SUBROUTINE NAME: V89CALL
# MOD NO: 0 DATE: 9 JAN 1968
# MOD BY: DIGITAL DEVEL GROUP LOG SECTION: R63
# FUNCTIONAL DESCRIPTION:
# CALLED BY VERB 89 ENTER DURING P00. PRIO 10 USED. CALCULATES AND
# DISPLAYS FINAL FDAI BALL ANGLES TO POINT LM +X OR +Z AXIS AT CSM.
# 1. KEY IN V 89 E ONLY IF IN PROG 00. IF NOT IN P00, OPERATOR ERROR AND
# EXIT R63, OTHERWISE CONTINUE.
# 2. IF IN P00, DO IMU STATUS CHECK ROUTINE (R02BOTH). IF IMU ON AND ITS
# ORIENTATION KNOWN TO LGC, CONTINUE.
# 3. FLASH DISPLAY V 04 N 06. R2 INDICATES WHICH SPACECRAFT AXIS IS TO
# BE POINTED AT CSM. INITIAL CHOICE IS PREFERRED (+Z) AXIS (R2=1).
# ASTRONAUT CAN CHANGE TO (+X) AXIS (R2 NOT =1) BY V 22 E 2 E. CONTINUE
# AFTER KEYING IN PROCEED.
# 4. BOTH VEHICLE STATE VECTORS UPDATED BY CONIC EQS.
# 5. HALF MAGNITUDE UNIT LOS VECTOR (IN STABLE MEMBER COORDINATES) AND
# HALF MAGNITUDE UNIT SPACECRAFT AXIS VECTOR (IN BODY COORDINATES)
# PREPARED FOR VECPOINT.
# 6. GIMBAL ANGLES FROM VECPOINT TRANSFORMED INTO FDAI BALL ANGLES BY
# BALLANGS. FLASH DISPLAY V 06 N 18 AND AWAIT RESPONSE.
# 7. RECYCLE - RETURN TO STEP 4.
# TERMINATE - EXIT R63.
# PROCEED - RESET 3AXISFLG AND CALL R60LEM FOR ATTITUDE MANEUVER.
# CALLING SEQUENCE: V 89 E.
# SUBROUTINES CALLED: CHKPOOH, R02BOTH, GOXDSPF, CSMCONIC, LEMCONIC,
# VECPOINT, BALLANGS, R60LEM.
# NORMAL EXIT MODES: TC ENDEXT
# ALARMS: 1. OPERATOR ERROR IF NOT IN P00.
# 2. PROGRAM ALARM IF IMU IS OFF.
# 3. PROGRAM ALARM IF IMU ORIENTATION IS UNKNOWN.
# OUTPUT: NONE
# ERASABLE INITIALIZATION REQUIRED: NONE
# DEBRIS: OPTION1, +1, TDEC1, POINTVSM, SCAXIS, CPHI, CTHETA, CPSI,
## Page 340
# 3AXISFLG.
EBANK= RONE
BANK 32
SETLOC BAWLANGS
BANK
COUNT* $$/R63
V89CALL TC BANKCALL # IMU STATUS CHECK. RETURNS IF ORIENTATION
CADR R02BOTH # KNOWN. ALARMS IF NOT.
CAF THREE # ALLOW ASTRONAUT TO SELECT DESIRED
TS OPTIONX # TRACKING ATTITUDE AXIS.
CAF ONE
TS OPTIONX +1
CAF VB04N12 # V 04 N 12
TC BANKCALL
CADR GOFLASH
TC ENDEXT # TERMINATE
TC +2 # PROCEED
TC -5 # DATA IN. OPTION1+1 = 1 FOR Z AXIS
V89RECL TC INTPRET # = 2 FOR X AXIS
RTB DAD
LOADTIME # READ PRESENT TIME
DP1MIN
STORE TSTART82 # SAVE TIME FOR LEMCONIC CALL
STCALL TDEC1 # STORE TIME FOR CSMCONIC CALL
CSMCONIC # CSM STATE VECTOR UPDATE
VLOAD # CSMCONIC LEFT R VECTOR IN RATT
RATT
STODL RONE # SAVE FOR LINE OF SIGHT (LOS) COMPUTATION
TSTART82
STCALL TDEC1 # STORE TIME FOR LEMCONIC CALL
LEMCONIC # LEM STATE VECTOR UPDATE
VLOAD VSU # CSM POSITION - LEM POSITION = LOS
RONE # LOS VECTOR LEFT IN MPAC
RATT
MXV RTB # (REFSMMAT X LOS). TRANSFORMS LOS FROM
REFSMMAT # REFERENCE COORD TO STAB MEMB COORD.
NORMUNIT
STORE POINTVSM # STORE LOS FOR VECPOINT CALL
EXIT
CS OPTIONX +1 # 1 FOR Z AXIS. 2 FOR X AXIS.
AD ONE
EXTEND
BZF ALINEZ
ALINEX TC INTPRET # X AXIS ALIGNMENT
VLOAD
UNITX # READ (.5, 0, 0)
## Page 341
V89CALL1 STCALL SCAXIS # STORE SELECTED ALIGNMENT AXIS
VECPOINT # PUTS DESIRED GIM ANG (OG,IG,MG) IN TMPAC
STORE CPHI # STORE GIMBAL ANGLES FOR BALLANGS CALL.
EXIT
TC BANKCALL
CADR BALLANGS # PUTS DESIRED BALL ANGLES IN FDAIX,Y,Z
CAF VB06N18 # V 06 N 18
TC BANKCALL # NOUN 18 REFERS TO FDAIX,Y,Z
CADR GOFLASH
TC ENDEXT # TERMINATE
TC +2 # PROCEED
TC V89RECL # RECYCLE
TC DOWNFLAG # RESET 3 AXIS FLAG
ADRES 3AXISFLG # RESET BIT6 FLAG WORD 5
TC BANKCALL # PERFORMS LEM MANEUVER TO ALIGN SELECTED
CADR R60LEM # SPACECRAFT AXIS TO CSM.
TCF ENDEXT # TERMINATE R63
ALINEZ TC INTPRET # Z AXIS ALIGNMENT
VLOAD GOTO
UNITZ # READ (0, 0, .5)
V89CALL1
VB04N12 VN 412
VB06N18 VN 0618
## Page 342
DP1MIN 2DEC 6000
