IMU_MODE_SWITCHING_ROUTINES.agc
# Copyright: Public domain.
# Filename: IMU_MODE_SWITCHING_ROUTINES.agc
# Purpose: Part of the source code for Luminary 1A build 099.
# It is part of the source code for the Lunar Module's (LM)
# Apollo Guidance Computer (AGC), for Apollo 11.
# Assembler: yaYUL
# Contact: Onno Hommes <ohommes@cmu.edu>.
# Website: www.ibiblio.org/apollo.
# Pages: 1309-1337
# Mod history: 2009-05-28 OH Transcribed from page images.
# 2009-06-05 RSB Fixed a typo.
# 2011-01-06 JL Fixed pseudo-label indentation.
# 2011-05-08 JL Removed workaround. Flagged SBANK=
# workaround for future removal.
# This source code has been transcribed or otherwise adapted from
# digitized images of a hardcopy from the MIT Museum. The digitization
# was performed by Paul Fjeld, and arranged for by Deborah Douglas of
# the Museum. Many thanks to both. The images (with suitable reduction
# in storage size and consequent reduction in image quality as well) are
# available online at www.ibiblio.org/apollo. If for some reason you
# find that the images are illegible, contact me at info@sandroid.org
# about getting access to the (much) higher-quality images which Paul
# actually created.
#
# Notations on the hardcopy document read, in part:
#
# Assemble revision 001 of AGC program LMY99 by NASA 2021112-061
# 16:27 JULY 14, 1969
# Page 1309
BLOCK 02
SETLOC FFTAG3
BANK
EBANK= COMMAND
# FIXED-FIXED ROUTINES
COUNT* $$/IMODE
ZEROICDU CAF ZERO # ZERO ICDU COUNTERS.
TS CDUX
TS CDUY
TS CDUZ
TC Q
SPSCODE = BIT9
# Page 1310
# IMU ZEROING ROUTINES
BANK 11
SETLOC MODESW
BANK
COUNT* $$/IMODE
IMUZERO INHINT # ROUTINE TO ZERO ICDUS.
CS DSPTAB +11D # DON'T ZERO CDUS IF IMU IN GIMBAL LOCK AND
MASK BITS4&6 # COARSE ALIGN (GIMBAL RUNAWAY PROTECTION)
CCS A
TCF IMUZEROA
TC ALARM # IF SO.
OCT 00206
TCF CAGETSTJ +4 # IMMEDIATE FAILURE.
IMUZEROA TC CAGETSTJ
CS IMODES33 # DISABLE DAP AUTO AND HOLD MODES
MASK SUPER011 # BIT5 FOR GROUND
ADS IMODES33
CS IMODES30 # INHIBIT ICDUFAIL AND IMUFAIL (IN CASE WE
MASK BITS3&4 # JUST CAME OUT OF COARSE ALIGN).
ADS IMODES30
CS BITS4&6 # SEND ZERO ENCODE WITH COARSE AND ERROR
EXTEND # COUNTER DISABLED.
WAND CHAN12
TC NOATTOFF # TURN OFF NO ATT LAMP.
CAF BIT5
EXTEND
WOR CHAN12
TC ZEROICDU
CAF BIT6 # WAIT 320 MS TO GIVE AGS ADEQUATE TIME TO
TC WAITLIST # RECEIVE ITS PULSE TRAIN.
EBANK= CDUIND
2CADR IMUZERO2
CS IMODES30 # SEE IF IMU OPERATING AND ALARM IF NOT.
MASK BIT9
CCS A
TCF MODEEXIT
# Page 1311
TC ALARM
OCT 210
MODEEXIT RELINT # GENERAL MODE-SWITCHING EXIT.
TCF SWRETURN
IMUZERO2 TC CAGETEST
TC ZEROICDU # ZERO CDUX, CDUY, CDUZ
CS BIT5 # REMOVE ZERO DISCRETE.
EXTEND
WAND CHAN12
CAF BIT11 # WAIT 10 SECS FOR CTRS TO FIND GIMBALS
TC VARDELAY
IMUZERO3 TC CAGETEST
CS BITS3&4 # REMOVE IMUFAIL AND ICDUFAIL INHIBIT.
MASK IMODES30
TS IMODES30
CS SUPER011 # ENABLE DAP AUTO AND HOLD MODES
MASK IMODES33 # BIT5 FOR GROUND
TS IMODES33
TC IBNKCALL # SET ISS WARNING IF EITHER OF ABOVE ARE
CADR SETISSW # PRESENT.
TCF ENDIMU
# Page 1312
# IMU COARSE ALIGN MODE.
IMUCOARS INHINT
TC CAGETSTJ
TC SETCOARS
CAF SIX
TC WAITLIST
EBANK= CDUIND
2CADR COARS
TCF MODEEXIT
COARS TC CAGETEST
CAF BIT6 # ENABLE ALL THREE ISS CDU ERROR COUNTERS
EXTEND
WOR CHAN12
CAF TWO # SET CDU INDICATOR
COARS1 TS CDUIND
INDEX CDUIND # COMPUTE THETAD -- THETAA IN 1'S
CA THETAD # COMPLEMENT FORM
EXTEND
INDEX CDUIND
MSU CDUX
EXTEND
MP BIT13 # SHIFT RIGHT 2
XCH L # ROUND
DOUBLE
TS ITEMP1
TCF +2
ADS L
INDEX CDUIND # DIFFERENCE TO BE COMPUTED
LXCH COMMAND
CCS CDUIND
TC COARS1
CAF TWO # MINIMUM OF 4 MS WAIT
TC VARDELAY
# Page 1313
COARS2 TC CAGETEST # DON'T CONTINUE IF CAGED.
TS ITEMP1 # SET TO +0.
CAF TWO # SET CDU INDICATOR.
+3 TS CDUIND
INDEX CDUIND
CCS COMMAND # NUMBER OF PULSES REQUIRED
TC COMPOS # GREATER THAN MAX ALLOWED
TC NEXTCDU +1
TC COMNEG
TC NEXTCDU +1
COMPOS AD -COMMAX # COMMAX = MAX NUMBER OF PULSES ALLOWED
EXTEND # MINUS ONE
BZMF COMZERO
INDEX CDUIND
TS COMMAND # REDUCE COMMAND BY MAX NUMBER OF PULSES
CS -COMMAX- # ALLOWED
NEXTCDU INCR ITEMP1
AD NEG0
INDEX CDUIND
TS CDUXCMD # SET UP COMMAND REGISTER.
CCS CDUIND
TC COARS2 +3
CCS ITEMP1 # SEE IF ANY PULSES TO GO OUT.
TCF SENDPULS
TC FIXDELAY # WAIT FOR GIMBALS TO SETTLE.
DEC 150
CAF TWO # AT END OF COMMAND, CHECK TO SEE THAT
CHKCORS TS ITEMP1 # GIMBALS ARE WITHIN 2 DEGREES OF THETAD.
INDEX A
CA CDUX
EXTEND
INDEX ITEMP1
MSU THETAD
CCS A
TCF COARSERR
TCF CORSCHK2
TCF COARSERR
# Page 1314
CORSCHK2 CCS ITEMP1
TCF CHKCORS
TCF ENDIMU # END OF COARSE ALIGNMENT
COARSERR AD COARSTOL # 2 DEGREES.
EXTEND
BZMF CORSCHK2
TC ALARM # COARSE ALIGN ERROR.
OCT 211
TCF IMUBAD
COARSTOL DEC -.01111 # 2 DEGREES SCALED AT HALF-REVOLUTIONS
COMNEG AD -COMMAX
EXTEND
BZMF COMZERO
COM
INDEX CDUIND
TS COMMAND
CA -COMMAX-
TC NEXTCDU
COMZERO CAF ZERO
INDEX CDUIND
XCH COMMAND
TC NEXTCDU
SENDPULS CAF 13,14,15
EXTEND
WOR CHAN14
CAF 600MS
TCF COARS2 -1 # THEN TO VARDELAY
CA+ECE CAF BIT6 # ENABLE ALL THREE ISS CDU ERROR COUNTERS
EXTEND
WOR CHAN12
TC TASKOVER
# Page 1315
SETCOARS CAF BIT4 # BYPASS IF ALREADY IN COARSE ALIGN
EXTEND
RAND CHAN12
CCS A
TC Q
CS BIT6 # CLEAR ISS ERROR COUNTERS
EXTEND
WAND CHAN12
CS BIT10 # KNOCK DOWN GYRO ACTIVITY
EXTEND
WAND CHAN14
CS ZERO
TS GYROCMD
CAF BIT4 # PUT ISS IN COARSE ALIGN
EXTEND
WOR CHAN12
CS DSPTAB +11D # TURN ON NO ATT LAMP
MASK OCT40010
ADS DSPTAB +11D
CS IMODES33 # DISABLE DAP AUTO AND HOLD MODES
MASK BIT6
ADS IMODES33
CS IMODES30 # DISABLE IMUFAIL
MASK BIT4
ADS IMODES30
RNDREFDR CS TRACKBIT # CLEAR TRACK FLAG
MASK FLAGWRD1
TS FLAGWRD1
CS DRFTBIT # CLEAR DRIFT FLAG
MASK FLAGWRD2
TS FLAGWRD2
CS REFSMBIT # CLEAR REFSMMAT FLAG
MASK FLAGWRD3
TS FLAGWRD3
TC Q
OCT40010 OCT 40010
# Page 1316
# IMU FINE ALIGN MODE SWITCH.
IMUFINE INHINT
TC CAGETSTJ # SEE IF IMU BEING CAGED.
CS BITS4-5 # RESET ZERO AND COARSE
EXTEND
WAND CHAN12
CS BIT6 # INSURE DAP AUTO AND HOLD MODES ENABLED
MASK IMODES33
TS IMODES33
TC NOATTOFF
CAF BIT10 # IMU FAIL WAS INHIBITED DURING THE
TC WAITLIST # PRESUMABLY PRECEDING COARSE ALIGN. LEAVE
EBANK= CDUIND
2CADR IFAILOK # IT ON FOR THE FIRST 5 SECS OF FINE ALIGN
CAF 2SECS
TC WAITLIST
EBANK= CDUIND
2CADR IMUFINED
TCF MODEEXIT
IMUFINED TC CAGETEST # SEE THAT NO ONE HAS CAGED THE IMU.
TCF ENDIMU
# Page 1317
IFAILOK TC CAGETSTQ # ENABLE IMU FAIL UNLESS IMU BEING CAGED.
TCF TASKOVER # IT IS.
CAF BIT4 # DON'T RESET IMU FAIL INHIBIT IF SOMEONE
EXTEND # HAS GONE INTO COARSE ALIGN.
RAND CHAN12
CCS A
TCF TASKOVER
CS IMODES30 # RESET IMUFAIL.
MASK BIT13
ADS IMODES30
CS BIT4
PFAILOK2 MASK IMODES30
TS IMODES30
TC IBNKCALL # THE ISS WARNING LIGHT MAY COME ON NOW
CADR SETISSW # THAT THE INHIBIT WAS BEEN REMOVED.
TCF TASKOVER
PFAILOK TC CAGETSTQ # ENABLE PIP FAIL PROG ALARM.
TCF TASKOVER
CS IMODES30 # RESET IMU AND PIPA FAIL BITS.
MASK BIT10
ADS IMODES30
CS IMODES33
MASK BIT13
ADS IMODES33
CS BIT5
TCF PFAILOK2
NOATTOFF CS OCT40010 # SUBROUTINE TO TURN OFF NO ATT LAMP.
MASK DSPTAB +11D
AD BIT15
TS DSPTAB +11D
TC Q
# Page 1318
# ROUTINES TO INITIATE AND TERMINATE PROGRAM USE OF THE PIPAS. NO IMUSTALL REQUIRED IN EITHER CASE.
PIPUSE CS ZERO
TS PIPAX
TS PIPAY
TS PIPAZ
PIPUSE1 TC CAGETSTQ # DO NOT ENABLE PIPA FAIL IF IMU IS CAGED
TCF SWRETURN
INHINT
CS BIT1 # IF PIPA FAILS FROM NOW ON (UNTIL
MASK IMODES30 # PIPFREE), LIGHT ISS WARNING.
TS IMODES30
PIPFREE2 TC IBNKCALL # ISS WARNING MIGHT COME ON NOW.
CADR SETISSW # (OR GO OFF ON PIPFREE).
TCF MODEEXIT
PIPFREE INHINT # PROGRAM DONE WITH PIPAS. DON'T LIGHT
CS IMODES30 # ISS WARNING.
MASK BIT1
ADS IMODES30
MASK BIT10 # IF PIP FAIL ON, DO PROG ALSRM AND RESET
CCS A # ISS WARNING.
TCF MODEEXIT
TC ALARM
OCT 212
INHINT
TCF PIPFREE2
# Page 1319
# THE FOLLOWING ROUTINE TORQUES THE IRIGS ACCORDING TO DOUBLE PRECISION INPUTS IN THE SIX REGISTERS
# BEGINNING AT THE ECADR ARRIVING IN A. THE MINIMUM SIZE OF ANY PULSE TRAIN IS 16 PULSES (.25 CDU COUNTS). THE
# UNSENT PORTION OF THE COMMAND IS LEFT INTACT IN THE INPUT COMMAND REGISTERS.
EBANK= 1400 # VARIABLE, ACTUALLY.
IMUPULSE TS MPAC +5 # SAVE ARRIVING ECADR.
TC CAGETSTJ # DON'T PROCEED IF IMU BEING CAGED.
CCS LGYRO # SEE IF GYROS BUSY.
TC GYROBUSY # SLEEP.
TS MPAC +2
CAF BIT6 # ENABLE THE POWER SUPPLY.
EXTEND
WOR CHAN14
CAF FOUR
GWAKE2 TC WAITLIST # (IF A JOB WAS PUT TO SLEEP, THE POWER
EBANK= CDUIND # SUPPLY IS LEFT ON BY THE WAKING JOB).
2CADR STRTGYRO
CA MPAC +5 # SET UP EBANK, SAVING CALLER'S EBANK FOR
XCH EBANK # RESTORATION ON RETURN.
XCH MPAC +5
TS LGYRO # RESERVES GYROS.
MASK LOW8
TS ITEMP1
CAF TWO # FORCE SIGN AGREEMENT ON INPUTS.
GYROAGRE TS MPAC +3
DOUBLE
AD ITEMP1
TS MPAC +4
EXTEND
INDEX A
DCA 1400
DXCH MPAC
TC TPAGREE
DXCH MPAC
INDEX MPAC +4
DXCH 1400
CCS MPAC +3
TCF GYROAGRE
CA MPAC +5 # RESTORE CALLER'S EBANK.
TS EBANK
TCF MODEEXIT
# Page 1320
# ROUTINES TO ALLOW TORQUING ONLY ONE JOB AT A TIME.
GYROBUSY EXTEND # SAVE RETURN 2FCADR.
DCA BUF2
DXCH MPAC
REGSLEEP CAF LGWAKE
TCF JOBSLEEP
GWAKE CCS LGYRO # WHEN AWAKENED, SEE IF GYROS STILL BUSY.
TCF REGSLEEP # IF SO, SLEEP SOME MORE.
TS MPAC +2
EXTEND
DCA MPAC
DXCH BUF2 # RESTORE SWRETURN INFO.
CAF ONE
TCF GWAKE2
LGWAKE CADR GWAKE
# Page 1321
# GYRO-TORQUING WAITLIST TASKS.
STRTGYRO CS GDESELCT # DE-SELECT LAST GYRO.
EXTEND
WAND CHAN14
TC CAGETEST
STRTGYR2 CA LGYRO # JUMP ON PHASE COUNTER IN BITS 13-14.
EXTEND
MP BIT4
INDEX A
TCF +1
TC GSELECT # =0. DO Y GYRO.
OCT 00202
TC GSELECT # =1. DO Z GYRO.
OCT 00302
TC GSELECT -2 # =2. DO X GYRO.
OCT 00100
CAF ZERO # =3. DONE
TS LGYRO
CAF LGWAKE # WAKE A POSSIBLE SLEEPING JOB.
TC JOBWAKE
NORESET TCF IMUFINED # DO NOT RESET POWER SUPPLY
# Page 1322
-2 CS FOUR # SPECIAL ENTRY TO REGRESS LGYRO FOR X.
ADS LGYRO
GSELECT INDEX Q # SELECT GYRO.
CAF 0 # PACKED WORD CONTAINS GYRO SELECT BITS
TS ITEMP4 # AND INCREMENT TO LGYRO.
MASK SEVEN
AD BIT13
ADS LGYRO
TS EBANK
MASK LOW8
TS ITEMP1
CS SEVEN
MASK ITEMP4
TS ITEMP4
EXTEND # MOVE DP COMMAND TO RUPTREGS FOR TESTING.
INDEX ITEMP1
DCA 1400
DXCH RUPTREG1
CCS RUPTREG1
TCF MAJ+
TCF +2
TCF MAJ-
CCS RUPTREG2
TCF MIN+
TCF STRTGYR2
TCF MIN-
TCF STRTGYR2
# Page 1323
MIN+ AD -GYROMIN # SMALL POSITIVE COMMAND. SEE IF AT LEAST
EXTEND # 16 GYRO PULSES.
BZMF STRTGYR2
MAJ+ EXTEND # DEFINITE POSITIVE OUTPUT.
DCA GYROFRAC
DAS RUPTREG1
CA ITEMP4 # SELECT POSITIVE TORQUING FOR THIS GYRO.
EXTEND
WOR CHAN14
CAF LOW7 # LEAVE NUMBER OF POSSIBLE 8192 AUGMENTS
MASK RUPTREG2 # TO INITIAL COMMAND IN MAJOR PART OF LONG
XCH RUPTREG2 # TERM STORAGE AND TRUNCATED FRACTION
GMERGE EXTEND # IN MINOR PART. THE MAJOR PART WILL BE
MP BIT8 # COUNTED DOWN TO ZERO IN THE COURSE OF
TS ITEMP2 # PUTTING OUT THE ENTIRE COMMAND.
CA RUPTREG1
EXTEND
MP BIT9
TS RUPTREG1
CA L
EXTEND
MP BIT14
ADS ITEMP2 # INITIAL COMMAND.
EXTEND # SEE IF MORE THAN ONE PULSE TRAIN NEEDED
DCA RUPTREG1 # (MORE THAN 16383 PULSES).
AD MINUS1
CCS A
TCF LONGGYRO
-GYROMIN OCT -176 # MAY BE ADJUSTED TO SPECIFY MINIMUM CMD
TCF +4
CAF BIT14
ADS ITEMP2
CAF ZERO
+4 INDEX ITEMP1
DXCH 1400
# Page 1324
CA ITEMP2 # ENTIRE COMMAND.
LASTSEG TS GYROCMD
EXTEND
MP BIT10 # WAITLIST DT
AD THREE # TRUNCATION AND PHASE UNCERTAINTIES.
TC WAITLIST
EBANK= CDUIND
2CADR STRTGYRO
GYROEXIT CAF BIT10
EXTEND
WOR CHAN14
TCF TASKOVER
LONGGYRO INDEX ITEMP1
DXCH 1400 # INITIAL COMMAND OUT PLUS N AUGMENTS OF
CAF BIT14 # 8192. INITIAL COMMAND IS AT LEAST 8192.
AD ITEMP2
TS GYROCMD
AUG3 EXTEND # GET WAITLIST DT TO TIME WHEN TRAIN IS
MP BIT10 # ALMOST OUT.
AD NEG3
TC WAITLIST
EBANK= CDUIND
2CADR 8192AUG
TCF GYROEXIT
8192AUG TC CAGETEST
CAF BIT4
EXTEND
RAND CHAN12
CCS A
TCF IMUBAD
CA LGYRO # ADD 8192 PULSES TO GYROCMD
TS EBANK
MASK LOW8
TS ITEMP1
INDEX ITEMP1 # SEE IF THIS IS THE LAST AUG.
CCS 1400
TCF AUG2 # MORE TO COME.
CAF BIT14
ADS GYROCMD
TCF LASTSEG +1
# Page 1325
AUG2 INDEX ITEMP1
TS 1400
CAF BIT14
ADS GYROCMD
TCF AUG3 # COMPUTE DT.
# Page 1326
MIN- AD -GYROMIN # POSSIBLE NEGATIVE OUTPUT.
EXTEND
BZMF STRTGYR2
MAJ- EXTEND # DEFINITE NEGATIVE OUTPUT.
DCS GYROFRAC
DAS RUPTREG1
CA ITEMP4 # SELECT NEGATIVE TORQUING FOR THIS GYRO.
AD BIT9
EXTEND
WOR CHAN14
CS RUPTREG1 # SET UP RUPTREGS TO FALL INTO GMERGE.
TS RUPTREG1 # ALL NUMBERS PUT INTO GYROCMD ARE
CS RUPTREG2 # POSITIVE -- BIT9 OF CHAN 14 DETERMINES
MASK LOW7 # THE SIGN OF THE COMMAND.
COM
XCH RUPTREG2
COM
TCF GMERGE
GDESELCT OCT 1700 # TURN OFF SELECT AND ACTIVITY BITS.
GYROFRAC 2DEC .215 B -21
# Page 1327
# IMU MODE SWITCHING ROUTINES COME HERE WHEN ACTION COMPLETE.
ENDIMU EXTEND # MODE IS BAD IF CAGE HAS OCCURRED OR IF
READ DSALMOUT # ISS WARNING IS ON.
MASK BIT1
CCS A
TCF IMUBAD
IMUGOOD TCF GOODEND # WITH C(A) = 0.
IMUBAD CAF ZERO
TCF BADEND
CAGETEST CAF BIT6 # SUBROUTINE TO TERMINATE IMU MODE
MASK IMODES30 # SWITCH IF IMU HAS BEEN CAGED.
CCS A
TCF IMUBAD # DIRECTLY.
TC Q # WITH C(A) = +0.
CAGETSTQ CS IMODES30 # SKIP IF IMU NOT BEING CAGED.
MASK BIT6
CCS A
INCR Q
TC Q
CAGETSTJ CS IMODES30 # IF DURING MODE SWITCH INITIALIZATION
MASK BIT6 # IT IS FOUND THAT THE IMU IS BEING CAGED,
CCS A # SET IMUCADR TO -0 TO INDICATE OPERATION
TC Q # COMPLETE BUT FAILED. RETURN IMMEDIATELY
CS ZERO # TO SWRETURN.
TS IMUCADR
TCF MODEEXIT
# Page 1328
# GENERALIZED MODE SWITCHING TERMINATION. ENTER AT GOODEND FOR SUCCESSFUL COMPLETION OF AN I/O OPERATION
# OR AT BADEND FOR A N UNSUCCESSFUL ONE. C(A) OR ARRIVAL =0 FOR IMU, 1 FOR OPTICS.
BADEND TS RUPTREG2 # DEVICE INDEX.
CS ZERO # FOR FAILURE.
TCF GOODEND +2
GOODEND TS RUPTREG2
CS ONE # FOR SUCCESS.
TS RUPTREG3
INDEX RUPTREG2 # SEE IF USING PROGRAM ASLEEP.
CCS MODECADR
TCF +4 # YES -- WAKE IT UP.
TCF ENDMODE # IF 0, PROGRAM NOT IN YET.
EXTEND
BZF ENDMODE +1 # BZF = TCF IF MODECADR = -0.
CAF ZERO # WAKE SLEEPING PROGRAM.
INDEX RUPTREG2
XCH MODECADR
TC JOBWAKE
CS RUPTREG3 # ADVANCE LOC IF SUCCESSFUL.
INDEX LOCCTR
ADS LOC
TCF TASKOVER
ENDMODE CA RUPTREG3 # -0 INDICATES OPERATION COMPLETE BUT
+1 INDEX RUPTREG2 # UNSUCCESSFUL: -1 INDICATES COMPLETE AND
TS MODECADR # SUCCESSFUL.
TCF TASKOVER
# Page 1329
# GENERAL STALLING ROUTINE. USING PROGRAMS COME HERE TO WAIT FOR I/O COMPLETION.
#
# PROGRAM DESCRIPTION DATE- 21 FEB 1967
# LOG SECTION IMU MODE SWITCHING
# MOD BY- R.MELANSON TO ADD DOCUMENTATION ASSEMBLY SUNDISK REV. 82
#
# FUNCTIONAL DESCRIPTION-
# TO DELAY FURTHER EXECUTION OF THE CALLING ROUTINE UNTIL ITS SELECTED
# I/O FUNCTION IS COMPLETE.THE FOLLOWING CHECKS ON THE CALLING ROUTINE:S
# MODECADR ARE MADE AND ACTED UPON.
# 1) +0 INDICATES INCOMPLETE I/O OPERATION.CALLING ROUTINE IS PUT TO
# SLEEP.
# 2) -1 INDICATES COMPLETED I/O OPERATION. STALL BYPASSES JOBSLEEP
# CALL AND RETURNS TO CALLING ROUTINE AT L+3
# 3) -0 INDICATES COMPLETED I/O WITH FAILURE. STALL CLEARS MODECADR
# AND RETURNS TO CALLING ROUTINE AT L+2.
# 4) VALUE GREATER THAN 0 INDICATES TWO ROUTINES CALLING FOR USE OF
# SAME DEVICE. STALL EXITS TO ABORT WHICH EXECUTES A PROGRAM
# RESTART WHICH IN TURN CLEARS ALL MODECADR REGISTERS.
#
# CALLING SEQUENCE-
# L TC BANKCALL
# L+1 CADR (ONE OF 5 STALL ADDRESSES I.E. IMUSTALL,OPTSTALL,RADSTALL,
# AOTSTALL,OR ATTSTALL)
#
# NORMAL-EXIT MODE-
# TCF JOBSLEEP OR TCF MODEXIT
#
# ALARM OR ABORT EXIT MODE-
# TC ABORT
#
# OUTPUT-
# MODECADR= CADR IF JOBSLEEP
# MODECADR=+0 IF I/O COMPLETE
# BUF2=L+3 IF I/O COMPLETE AND GOOD.
# BUF2=L+2 IF I/O COMPLETE BUT FAILED.
#
# ERASABLE INITIALIZATION-
# BUF2 CONTAINS RETURN ADDRESS PLUS 1,(L+2)
# BUF2+1 CONTAINS FBANK VALUE OF CALLING ROUTINE.
# MODECADR OF CALLING ROUTINE CONTAINS +0,-1,-0 OR CADR RETURN ADDRESS.
#
# DEBRIS-
# RUPTREG2 AND CALLING ROUTINE MODECADR.
AOTSTALL CAF ONE # AOT.
TC STALL
RADSTALL CAF TWO
TCF STALL
# Page 1330
OPTSTALL EQUALS AOTSTALL
IMUSTALL CAF ZERO # IMU.
STALL INHINT
TS RUPTREG2 # SAVE DEVICE INDEX.
INDEX A # SEE IF OPERATION COMPLETE.
CCS MODECADR
TCF MODABORT # ALLOWABLE STATES ARE +0, -1, AND -0.
TCF MODESLP # OPERATION INCOMPLETE.
TCF MODEGOOD # COMPLETE AND GOOD IF = -1.
MG2 INDEX RUPTREG2 # COMPLETE AND FAILED IF -0. RESET TO +0.
TS MODECADR # RETURN TO CALLER.
TCF MODEEXIT
MODEGOOD CCS A # MAKE SURE INITIAL STATE -1.
TCF MODABORT
INCR BUF2 # IF SO, INCREMENT RETURN ADDRESS AND
TCF MG2 # RETURN IMMEDIATELY, SETTING CADR = +0.
MODESLP TC MAKECADR # CALL FROM SWITCHABLE FIXED ONLY.
INDEX RUPTREG2
TS MODECADR
TCF JOBSLEEP
MODABORT DXCH BUF2
TC BAILOUT1 # TWO PROGRAMS USING THE SAME DEVICE.
OCT 1210
# Page 1331
# CONSTANTS FOR MODE SWITCHING ROUTINES
BITS3&4 = OCT14
BITS4&6 = OCT50
BITS4-5 OCT 00030
IMUSEFLG EQUALS BIT8 # INTERPRETER SWITCH 7.
-COMMAX DEC -191
-COMMAX- DEC -192
600MS DEC 60
IMUFIN20 = IMUFINE
GOMANUR CA ATTCADR # IS KALCMANU FREE
EXTEND
BZF +3
TC POODOO # NO
OCT 1210 # 2 TRYING TO USE SAME DEVICE
+3 EXTEND
DCA BUF2
DXCH ATTCADR # SAVE FINAL RETURN FOR KALCMAN3
CA BBANK
MASK SEVEN
ADS ATTCADR +1
CA PRIORITY
MASK PRIO37
TS ATTPRIO # SAVE USERS PRIO
CAF KALEBCON # SET EBANK FOR KALCMAN3
TS EBANK
TC POSTJUMP
CADR KALCMAN3
KALEBCON ECADR BCDU
# Page 1332
# PROGRAM DESCRIPTION
# IMU STATUS CHECK ROUTINE R02 (SUBROUTINE UTILITY)
# MOD NO - 1
# MOD BY - N.BRODEUR
# FUNCTIONAL DESCRIPTION
#
# TO CHECK WHETHER IMU IS ON AND IF ON WHETHER IT IS ALIGNED TO AN
# ORIENTATION KNOWN BY THE CMC. TO REQUEST SELECTION OF THE APPROPRIATE
# PROGRAM IF THE IMU IS OFF OR NOT ALIGNED TO AN ORIENTATION KNOWN BY THE
# CMC. CALLED THROUGH BANKCALL
# CALLING SEQUENCE-
#
# L TC BANKCALL
# L+1 CADR R02BOTH
# SUBROUTINES CALLED
#
# VARALARM
# FLAGUP
# NORMAL EXIT MODES
#
# AT L+2 OF CALLING SEQUENCE
# ALARM OR ABORT EXIT MODES
# GOTOPOOH, WITH ALARM
# ERASABLE INITIALIZATION REQUIRED
#
# NONE
# DEBRIS
#
# CENTRALS-A,Q,L
BANK 34
SETLOC R02
BANK
COUNT* $$/R02
DEC51 DEC 51
R02BOTH CAF REFSMBIT
MASK FLAGWRD3
CCS A
TC R02ZERO # ZERO IMUS
CA IMODES30
MASK BIT9 # IS ISS INITIALIZED
EXTEND
BZF +2
CS BIT4 # SEND IMU ALARM CODE 210
AD OCT220 # SEND REFSMM ALARM
TC VARALARM
TC GOTOPOOH
R02ZERO TC UPFLAG
# Page 1333
ADRES IMUSE
TCF SWRETURN
OCT220 OCT 220
# Page 1334
# PROGRAM DESCRIPTION P06 10FEB67
#
# TRANSFER THE ISS/CMC FROM THE OPERATE TO THE STANDBY CONDITION.
#
# THE NORMAL CONDITION OF READINESS OF THE GNCS WHEN NOT IN USE IS STANDBY. IN THIS CONDITION THE IMU
# HEATER POWER IS ON. THE IMU OPERATE POWER IS OFF. THE COMPUTER POWER IS ON. THE OPTICS POWER IS OFF. THE
# CMC STANDBY ON THE MAIN AND LEB DISKYS IS ON.
#
# CALLING SEQUENCE:
# ASTRONAUT REQUEST THROUGH DSKY V37E 06E.
#
# SUBROUTINES CALLED:
# GOPERF1
# BANKCALL
# FLAGDOWN
#
# Page 1335
# PRESTAND PREPARES FOR STANDBY BY SNAPSHOTTING THE SCALER AND TIME1 TIME2
# THE LOW 5 BITS OF THE SCALER ARE INSPECTED TO INSURE COMPATIBILITY
# BETWEEN THE SCALER READING AND THE TIME1 TIME2 READING.
SETLOC P05P06
BANK
EBANK= TIME2SAV
COUNT* $$/P06
P06 TC UPFLAG # SET NODOV37 BIT
ADRES NODOFLAG
PRESTAND INHINT
EXTEND
DCA TIME2 # SNAPSHOT TIME1TIME2
DXCH TIME2SAV
TC SCALPREP
TC PRESTAND # T1,T2,SCALER NOT COMPATIBLE
DXCH MPAC # T1,T2 AND SCALER OK
DXCH SCALSAVE # STORE SCALER
INHINT
TC BANKCALL
CADR RNDREFDR # REFSMM, DRIFT, TRACK FLAGS DOWN
TC DOWNFLAG
ADRES IMUSE # IMUSE DOWN
TC DOWNFLAG
ADRES RNDVZFLG # RNDVZFLG DOWN
CAF BIT11
EXTEND
WOR CHAN13 # SET STANDBY ENABLE BIT
TC PHASCHNG # SET RESTART TO POSTAND WHEN STANDBY
OCT 07024 # RECOVERS
OCT 20000
EBANK= SCALSAVE
2CADR POSTAND
CAF OCT62
TC BANKCALL
CADR GOPERF1
TCF -3
TCF -4
TCF -5
OCT62 EQUALS .5SEC # DEC 50 = OCT 62
# THE LOW 5 BITS OF THE SCALER READS 10000 FOR THE FIRST INTERVAL AFTER A
# Page 1336
# T1 INCREMENT. IF SCALPREP DETECTS THIS INTERVAL THE T1,T2 AND SCALER
# DATA ARE NOT COMPATIBLE AND RETURN IS TO L+1 FOR ANOTHER READING OF THE
# DATA. OTHERWISE, THE RETURN IS TO L+2 TO PROCEED. ROUTINE ALSO PREPARES
# THE SCALER READING FOR COMPUTATION OF THE INCREMENT TO UPDATE T1T2. (THE
# 10 MS BIT (BIT 6) OF THE SCALER IS INCREMENTED 5 MS OUT OF PHASE FROM
# T1.) ADDITION OF 5 MS (BIT 5) TO THE SCALER READING HAS THE EFFECT OF
# ADJUSTING BIT 6 IN THE SCALER TO BE IN PHASE WITH BIT 1 OF T1. THE LOW 5
# BITS OF THE SCALER READING ARE THEN SET TO ZERO, TO TRUNCATE THE SCALER
# DATA TO 10 MS. RESULTS ARE STORED IN MPAC, +1.
SCALPREP EXTEND
QXCH MPAC +2
TC FINETIME +1
RELINT
DXCH MPAC
CA BIT5 # ADD 5 MS TO THE SCALER READING.
TS L
CA ZERO
DAS MPAC
CS LOW5 # SET LOW 5 BITS OF (SCALER+5MS) TO ZERO
MASK MPAC +1 # AND STORE RESULTS IN MPAC,+1.
XCH MPAC +1
MASK LOW5 # TEST LOW 5 BITS OF SCALER FOR THE FIRST
# INTERVAL AFTER THE T1 INCREMENT
# (NOW = 00000, SINCE BIT 5 ADDED).
CCS A # IS IT 1ST INTERVAL AFTER T1 INCREMENT
INCR MPAC +2 # NO
TC MPAC +2 # YES
# POSTAND RECOVERS TIME AFTER STANDBY.THE SCALER IS SNAPSHOTTED AND THE
# TIME1 TIME2 COUNTER IS SET TO ZERO. THE LOW 5 BITS OF THE SCALER ARE
# INSPECTED TO INSURE COMPATIBILITY BETWEEN THE SCALER READING AND THE
# CLEARING OF THE TIME COUNTER. IT THEN COMPUTES THE DIFFERENCE IN SCALER
# VALUES (IN DP) AND ADDS THIS TO THE PREVIOUSLY SNAPSHOTTED VALUES OF
# TIME1 TIME2 AND PLACES THIS NEW TIME INTO THE TIME1 TIME2 COUNTER.
COUNT* $$/P05
POSTAND CS BIT11 # RECOVER TIME AFTER STANDBY.
EXTEND
WAND CHAN13 # CLEAR STANDBY ENABLE BIT
INHINT
CA ZERO
TS L
DXCH TIME2 # CLEAR TIME1TIME2
TC SCALPREP # STORE SCALER IN MPAC, MPAC+1
TC POSTAND +3 # T1,T2,SCALER NOT COMPATIBLE
EXTEND # T1,T2 AND SCALER OK
DCS SCALSAVE
DAS MPAC # FORM DP DIFFERENCE OF POSTSTANDBY SCALER
# Page 1337
CAF BIT10 # MINUS PRESTANDBY SCALER AND SHIFT RIGHT
TC SHORTMP # 5 TO ALIGN BITS WITH TIME1TIME2.
CAF ZERO
TS MPAC +2 # NEEDED FOR TP AGREE
TC TPAGREE # MAKE DP DIFF AGREE
CCS MPAC
TC POSTCOM # IF DP DIFF NET +, NO SCALER OVERFLOW
TC POSTCOM # BETWEEN PRE AND POST STANDBY.
TC +1 # IF DP DIFF NET -, SCALER OVERFLOWED. ADD
CAF BIT10 # BIT 10 TO HIGH DIFF TO CORRECT.
ADS MPAC
POSTCOM EXTEND # C(MPAC,+1) IS MAGNITUDE OF DELTA SCALER.
DCA TIME2SAV # PRESTANDBY TIME1TIME2
DAS MPAC
TC TPAGREE # FORCE SIGN AGREEMENT
DXCH MPAC # UPDATED VALUE FOR T1,T2.
DAS TIME2 # LOAD UPDATED VALUE INTO T1,T2, WITH
TC DOWNFLAG # CLEAR NODOFLAG
ADRES NODOFLAG
TC GOTOPOOH
