R60,R62.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: R60_62.agc
## Purpose: Part of the source code for Artemis (i.e., Colossus 3),
## build 072. This is for the Command Module's (CM)
## Apollo Guidance Computer (AGC), for
## Apollo 15-17.
## Assembler: yaYUL
## Contact: Sergio Navarro <sergionavarrog@gmail.com>
## Website: www.ibiblio.org/apollo/index.html
## Page Scans: www.ibiblio.org/apollo/ScansForConversion/Artemis072/
## Mod history: 2009-08-19 SN Adapted from corresponding Comanche 055 file.
## 2009-09-03 JL Fixed symbol names.
## 2009-09-04 JL Fixed typo in COUNT* directive. Minor fixes.
## Removed a spurious SETPD in interpretive code.
## 2010-01-31 JL Fixed build errors.
## 2010-02-01 JL Fixed build errors.
## 2010-02-20 RSB Un-##'d this header.
## 2017-01-27 RSB Back-ported a comment-text fix identified in Luminary 69.
## 2017-02-08 RSB Proofed comment text by diff'ing vs Comanche 55
## and/or octopus/ProoferComments as most-appropriate.
## Page 394
SETLOC MANUVER
BANK
EBANK= TEMPR60
COUNT* $$/R60
# R60CSM
# REV 13 CONFORMS TO GSOP CHAPTER FOUR REVISION LOGIC 09 JAN 18,1968
R60CSM TC MAKECADR
TS TEMPR60
REDOMANN TC INTPRET
BON CALL # IS 3-AXIS FLAG SET
3AXISFLG
TOBALL1 # YES
VECPOINT # NO CALL VECPOINT
STORE CPHI
TOBALL1 EXIT
TOBALL CAF V06N18
TC BANKCALL
CADR GOPERF2R # DISPLAY PLEASE PERFORM AUTO MANEUVER
TC R61TEST
TC REDOMANC -1
TCF ENDMANU1 # ENTER I.E. FINISHED WITH R60
TC CHKLINUS # TO CHECK FOR PRIORITY DISPLAYS
TC ENDOFJOB
-1 TC INTPRET
REDOMANC BON CALL # IS 3-AXIS FLAG SET
3AXISFLG
+3 # YES
VECPOINT # NO CALL VECPOINT
STORE CPHI # STORE ANGLES
EXIT
TOBALLC CAF FURST3 # BITS 15,14,13 OF CHAN31 = 011
TC C31BTCHK # FOR AUTO AND G&N CONTROL
TCF +1
AD NEG30000
EXTEND
BZF +2 # AUTO, NON-FLASH N18
TCF TOBALL # NOT AUTO
## Page 395
CAF V06N18 # SET UP NON-FLASHING V06 N18
TC BANKCALL
CADR GODSPR
TC CHKLINUS
STARTMNV TC POSTJUMP
CADR KALCMAN3
ENDMANUV TC INTPRET
BOFF BOFF
AUTOSEQ
TOBALL1
TRACKFLG
TOBALL1
EXIT
ENDMANU1 CA TEMPR60
TC BANKJUMP # -
CHKLINUS CS FLAGWRD4
MASK PDSPFBIT # IS PRIORITY DISPLAY FLAG SET
CCS A # -
TC Q # NO - EXIT
CA Q
TS MPAC +2 # SAVE RETURN
CS THREE # OBTAIN LOCATION FOR RESTART.
AD BUF2 # HOLDS Q OF LAST DISPALY
TS TBASE1
TC PHASCHNG
OCT 71 # 1.7SPOT FOR RELINUS
1P7SPT1 = 1.7SPOT
CAF BIT7
TC LINUS # GO SET BITS FOR PRIORITY DISPLAY -
TC MPAC +2
RELINUS CAF TRACKBIT # IS TRACK FLAG ON
MASK FLAGWRD1
EXTEND
BZF GOREDO20 # NO
TC UPFLAG
ADRES PDSPFLAG # R60 PRIODSP FLAG
CA FLAGWRD8
MASK UTBIT
CCS A
TC RELINUSX # UTFLAG SET,DO NOT SET TARG1FLG,OPTIND
## Page 396
TC UPFLAG
ADRES TARG1FLG # FOR R52
CAF ZERO # RESET TO ZERO, SINCE
TS OPTIND # OPTIND WAS SET TO -1 BY V379
TC UPFLAG
ADRES R21MARK # ALLOW OPTICS MARKING DURING P2
RELINUSX CAF PRIO14 # RESTORE ORIGINAL PRIORITY
TC PRIOCHNG
TC TBASE1
GOREDO20 TC POSTJUMP # RESTORE R03 DEADBAND, DO STOPRATE,
CADR FIXDB # SET UP 1.11 RESTART, EOJ.
R61TEST CA MODREG # ARE WE IN P00. IF YES THIS MUST BE
EXTEND # VERB49 OR VERB89 SO DO ENDEXT.
BZF ENDMANU1 # RESET 3-AXIS & RUTURN. USER DOES ENDEXT
CA FLAGWRD4 # ARE WE IN R61 (P20)
MASK PDSPFBIT
EXTEND
BZF GOTOPOOH # NO
TC GOTOV56 # YES
## Page 397
# PROGRAM DESCRIPTION - VECPOINT
# THIS INTERPRETIVE SUBROUTINE MAY BE USED TO POINT A SPACECRAFT AXIS IN A DESIRED DIRECTION. THE AXIS
# TO BE POINTED MUST APPEAR AS A HALF UNIT DOUBLE PRECISION VECTOR IN SUCCESSIVE LOCATIONS OF ERASABLE MEMORY
# BEGINNING WITH THE LOCATION CALLED SCAXIS. THE COMPONENTS OF THIS VECTOR ARE GIVEN IN SPACECRAFT COORDINATES.
# THE DIRECTION IN WHICH THIS AXIS IS TO BE POINTED MUST APPEAR AS A HALF UNIT DOUBLE PRECISION VECTOR IN
# SUCCESSIVE LOCATIONS OF ERASABLE MEMORY BEGINNING WITH THE ADDRESS CALLED POINTVSM. THE COMPONENTS OF THIS
# VECTOR ARE GIVEN IN STABLE MEMBER COORDINATES. WITH THIS INFORMATION VECPOINT COMPUTES A SET OF THREE GIMBAL
# ANGLES (2S COMPLEMENT) CORRESPONDING TO THE CROSS-PRODUCT ROTATION BETWEEN SCAXIS AND POINTVSM AND STORES THEM
# IN T(MPAC) BEFORE RETURNING TO THE CALLER.
# THIS ROTATION, HOWEVER, MAY BRING THE S/C INTO GIMBAL LOCK. WHEN POINTING A VECTOR IN THE Y-Z PLANE,
# THE TRANSPONDER AXIS, OR THE AOT FOR THE LEM, THE PROGRAM WILL CORRECT THIS PROBLEM BY ROTATING THE CROSS-
# PRODUCT ATTITUDE ABOUT POINTVSM BY A FIXED AMOUNT SUFFICIENT TO ROTATE THE DESIRED S/C ATTITUDE OUT OF GIMBAL
# LOCK. IF THE AXIS TO BE POINTED IS MORE THAN 40.6 DEGREES BUT LESS THAN 60.5 DEG FROM THE +X (OR -X) AXIS,
# THE ADDITIONAL ROTATION TO AVOID GIMAL LOCK IS 35 DEGREES. IF THE AXIS IS MORE THAN 60.5 DEGEES FROM +X (OR -X)
# THE ADDITIONAL ROTATION IS 35 DEGREES. THE GIMBAL ANGLES CORRESPONDING TO THIS ATTITUDE ARE THEN COMPUTED AND
# STORED AS 2S COMPLIMENT ANGLES IN T(MPAC) BEFORE RETURNING TO THE CALLER.
# WHEN POINTING THE X-AXIS, OR THE THRUST VECTOR, OR ANY VECTOR WITHIN 40.6 DEG OF THE X-AXIS, VECPOINT
# CANNOT CORRECT FOR A CROSS-PRODUCT ROTATION INTO GIMBAL LOCK. IN THIS CASE A PLATFORM REALIGNMENT WOULD BE
# REQUIRED TO POINT THE VECTOR IN THE DESIRED DIRECTION. AT PRESENT NO INDICATION IS GIVEN FOR THIS SITUATION
# EXCEPT THAT THE FINAL MIDDLE GIMBAL ANGLE IN MPAC +2 IS GREATER THAN 59 DEGREES.
#
# CALLING SEQUENCE -
#
# 1) LOAD SCAXIS, POINTVSM
# 2) CALL
# VECPOINT
#
# RETURNS WITH
#
# 1) DESIRED OUTER GIMBAL ANGLE IN MPAC
# 2) DESIRED INNER GIMBAL ANGLE IN MPAC +1
# 3) DESIRED MIDDLE GIMBAL ANGLE IN MPAC +2
#
# ERASABLES USED -
#
# 1) SCAXIS 6
# 2) POINTVSM 6
# 3) MIS 18
# 4) DEL 18
# 5) COF 6
# 6) VECQTEMP 1
# 7) ALL OF VAC AREA 43
#
# TOTAL 99
SETLOC VECPT
BANK
## Page 398
EBANK= BCDU
COUNT* $$/VECPT
VECPOINT STQ BOV # SAVE RETURN ADDRESS
VECQTEMP
VECLEAR # AND CLEAR OVFIND
VECLEAR AXC,2 RTB
MIS # READ THE PRESENT CDU ANGLES AND
READCDUK # STORE THEM IN PD25, 26, 27
STCALL 25D
CDUTODCM # S/C AXES TO STABLE MEMBER AXES (MIS)
VLOAD VXM
POINTVSM # RESOLVE THE POINTING DIRECTION VF INTO
MIS # INITIAL S/C AXES (VF = POINTVSM)
UNIT
STORE 28D
# PD 28 29 30 31 32 33
VXV UNIT # TAKE THE CROSS PRODUCT VF X VI
SCAXIS # WHERE VI = SCAXIS
BOV VCOMP
PICKAXIS
STODL COF # CHECK MAGNITUDE
36D # OF CROSS PRODUCT
DSU BMN # VECTOR, IF LESS
DPB-14 # THAN B-14 ASSUME
PICKAXIS # UNIT OPERATION
VLOAD DOT # INVALID.
SCAXIS
28D
SL1 ARCCOS
COMPMATX CALL # NOW COMPUTE THE TRANSFORMATION FROM
DELCOMP # FINAL S/C AXES TO INITIAL S/C AXES MFI
AXC,1 AXC,2
MIS # COMPUTE THE TRANSFORMATION FROM FINAL
DEL # S/C AXES TO STABLE MEMBER AXES
CALL # MFS = MIS MFI
MXM3 # (IN PD LIST)
DLOAD ABS
6 # MFS6 = SIN(CPSI) $2
DSU BMN
SINGIMLC # = SIN(59 DEGS) $2
FINDGIMB # /CPSI/ LESS THAN 59 DEGS
# I.E. DESIRED ATTITUDE NOT IN GIMBAL LOCK
DLOAD ABS # CHECK TO SEE IF WE ARE POINTING
SCAXIS # THE THRUST AXIS
DSU BPL
SINVEC1 # SIN 49.4 DEGS $2
FINDGIMB # IF SO, WE ARE TRYING TO POINT IT INTO
## Page 399
VLOAD # GIMBAL LOCK, ABORT COULD GO HERE
STADR
STOVL MIS +12D
STADR # STORE MFS (IN PD LIST) IN MIS
STOVL MIS +6
STADR
STOVL MIS
MIS +6 # INNER GIMBAL AXIS IN FINAL S/C AXES
BPL VCOMP # LOCATE THE IG AXIS DIRECTION CLOSEST TO
IGSAMEX # FINAL X S/C AXIS
IGSAMEX VXV BMN # FIND THE SHORTEST WAY OF ROTATING THE
SCAXIS # S/C OUT OF GIMBAL LOCK BY A ROTATION
U=SCAXIS # ABOUT +- SCAXIS, I.E. IF (IG (SGN MFS3)
# X SCAXIS . XF) LESS THAN 0, U = SCAXIS
# OTHERWISE U = -SCAXIS
VLOAD VCOMP
SCAXIS
STCALL COF # ROTATE ABOUT -SCAXIS
CHEKAXIS
U=SCAXIS VLOAD
SCAXIS
STORE COF # ROTATE ABOUT + SCAXIS
CHEKAXIS DLOAD ABS
SCAXIS # SEE IF WE ARE POINTING THE AOT
DSU BPL
SINVEC2 # SIN 29.5 DEGS $2
PICKANG1 # IF SO, ROTATE 50 DEGS ABOUT +- SCAXIS
DLOAD GOTO # IF NOT, MUST BE POINTING THE TRANSPONDER
VECANG2 # OR SOME VECTOR IN THE Y, OR Z PLANE
COMPMFSN # IN THIS CASE ROTATE 35 DEGS TO GET OUT
# OF GIMBAL LOCK (VECANG2 $360)
PICKANG1 DLOAD
VECANG1 # = 50 DEGS $ 360
COMPMFSN CALL
DELCOMP # COMPUTE THE ROTATION ABOUT SCAXIS TO
AXC,1 AXC,2 # BRING MFS OUT OF GIMBAL LOCK
MIS
DEL
CALL # COMPUTE THE NEW TRANSFORMATION FROM
MXM3 # DESIRED S/C AXES TO STABLE MEMBER AXES
# WHICH WILL ALIGN VI WITH VF AND AVOID
# GIMBAL LOCK
FINDGIMB AXC,1 CALL
0 # EXTRACT THE COMMANDED CDU ANGLES FROM
DCMTOCDU # THIS MATRIX
RTB
V1STO2S # CONVERT TO 2:S COMPLEMENT
VECPTRET SETPD GOTO
## Page 400
0
VECQTEMP # RETURN TO CALLER
PICKAXIS VLOAD DOT # IF VF X VI = 0, FIND VF . VI
28D
SCAXIS
BMN TLOAD
ROT180
25D
GOTO # IF VF = VI, CDU DESIRED = PRESENT CDU
VECPTRET # PRESENT CDU ANGLES
ROT180 VLOAD VXV # IF VF, VI ANTIPARALLEL, 180 DEG ROTATION
MIS +6 # IS REQUIRED. Y STABLE MEMBER AXIS IN
HIUNITX # INITIAL S/C AXIS.
UNIT VXV # FIND Y(SM) X X(I)
SCAXIS # FIND UNIT(VI X UNIT(Y(SM) X X(I)))
UNIT BOV # I.E. PICK A VECTOR IN THE PLANE OF X(I),
PICKX # Y(SM) PERPENDICULAR TO VI
STODL COF
36D # CHECK MAGNITUDE
DSU BMN # OF THIS VECTOR.
DPB-14 # IF LESS THAN B-14,
PICKX # PICK X-AXIS.
VLOAD
COF
XROT STODL COF
HIDPHALF
GOTO
COMPMATX
PICKX VLOAD GOTO # PICK THE XAXIS IN THIS CASE
HIUNITX
XROT
SETLOC MANUVER1
BANK
COUNT* $$/VECPT
SINGIMLC 2DEC .4285836003 # = SIN(59) $2
SINVEC1 2DEC .3796356537 # = SIN(49.4) $2
SINVEC2 2DEC .2462117800 # = SIN(29.5) $2
VECANG1 2DEC .1388888889 # = 50 DEGREES $360
VECANG2 2DEC .09722222222 # = 35 DEGREES $360
1BITDP OCT 0 # KEEP THIS BEFORE DPB(-14) *********
DPB-14 OCT 00001
OCT 00000
SETLOC MANUVER
## Page 401
BANK
## Page 402
# ROUTINE FOR INITIATING AUTOMATIC MANEUVER VIA KEYBOARD (V49)
EBANK= CPHI
COUNT* $$/R62
R62DISP CAF V06N22 # DISPLAY COMMAND ICDUS CPHI, CTHETA, CPHI
TC BANKCALL
CADR GOFLASH
TCF ENDEXT
TCF GOMOVE # PROCEED
TCF R62DISP # ENTER
# ASTRONAUT MAY LOAD NEW ICDUS AT THIS
# POINT
GOMOVE TC UPFLAG # SET 3-AXIS FLAG
ADRES 3AXISFLG # BIT 6 FLAG 5
TC BANKCALL
CADR R60CSM
TCF ENDEXT
