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R30.agc
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### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: R30.agc
## Purpose: Part of the source code for Colossus, build 249.
## It is part of the source code for the Command Module's (CM)
## Apollo Guidance Computer (AGC), for Apollo 9.
## Assembler: yaYUL
## Reference: pp. 505-515.
## Contact: Ron Burkey <info@sandroid.org>.
## Website: www.ibiblio.org/apollo.
## Mod history: 08/02/04 RSB. Adapted from corresponding Luminary131 file.
## 2017-01-06 RSB Page numbers now agree with those on the
## original harcopy, as opposed to the PDF page
## numbers in 1701.pdf.
## 2017-01-18 RSB Cross-diff'd comment text (not whitespace)
## vs the already-proofed corresponding Colossus
## 237 and Comanche 55 source-code files
## and corrected errors found.
## 2017-02-08 RSB Comment-text fixes discovered while proofing Artemis 72.
##
## The contents of the "Colossus249" files, in general, are transcribed
## from a scanned copy of the program listing. Notations on this
## document read, in part:
##
## Assemble revision 249 of AGC program Colossus by NASA
## 2021111-041. October 28, 1968.
##
## This AGC program shall also be referred to as
## Colossus 1A
##
## Prepared by
## Massachusetts Institute of Technology
## 75 Cambridge Parkway
## Cambridge, Massachusetts
## under NASA contract NAS 9-4065.
##
## Refer directly to the online document mentioned above for further information.
## Please report any errors (relative to the scanned pages) to info@sandroid.org.
##
## In some cases, where the source code for Luminary 131 overlaps that of
## Colossus 249, this code is instead copied from the corresponding Luminary 131
## source file, and then is proofed to incorporate any changes.
## Page 505
# SUBROUTINE NAME: V82CALL
# MOD NO: 0 DATE: 16 FEB 67
# MOD BY: RR BAIRNSFATHER LOG SECTION: R30
# MOD NO: 1 MOD BY: RR BAIRNSFATHER DATE: 11 APR 67 SR30.1 CHANGED TO ALLOW MONITOR OPERN
# MOD NO: 2 MOD BY ALONSO DATE: 11 DEC 67 VB82 PROGRAM REWRITTEN
# MOD NO: 3 MOD BY ALONSO DATE: 26 MAR 68 PROG MOD TO HANDLE DIF EARTH/MOON SCALE
#
# NEW FUNCTIONAL DESCRIPTION: CALLED BY VERB 82 ENTER. PRIORITY 10
# USED THROUGHOUT. CALCULATE AND DISPLAY ORBITAL PARAMETERS
#
# 1. IF AVERAGE G IS OFF:
# FLASH DISPLAY V04N06. R2 INDICATES WHICH SHIP'S STATE VECTOR IS
# TO BE UPDATED. INITIAL CHOICE IS THIS SHIP (R2=1). ASTRONAUT
# CAN CHANGE TO OTHER SHIP BY V22EXE, WHERE X NOT EQ 1.
# SELECTED STATE VECTOR UPDATED BY THISPREC (OTHPREC).
# CALLS SR30.1 (WHICH CALLS TFFCONMU + TFFRP/RA) TO CALCULATE
# RPER (PERIGEE RADIUS), RAPO (APOGEE RADIUS), HPER (PERIGEE
# HEIGHT ABOVE LAUNCH PAD OR LUNAR LANDING SITE), HAPO (APOGEE
# HEIGHT AS ABOVE), TPER (TIME TO PERIGEE), TFF (TIME TO
# INTERSECT 300 KFT ABOVE PAD OR 35KFT ABOVE LANDING SITE).
# FLASH MONITOR V16N44 (HAPO, HPER, TFF). TFF IS -59M59S IF IT WAS
# NOT COMPUTABLE, OTHERWISE IT INCREMENTS ONCE PER SECOND.
# ASTRONAUT HAS OPTION TO MONITOR TPER BY KEYING IN N 32 E.
# DISPLAY IS IN HMS, IS NEGATIVE (AS WAS TFF), AND INCREMENTS
# ONCE PER SECOND ONLY IF TFF DISPLAY WAS -59M59S.
# 2. IF AVERAGE G IS ON:
# CALLS SR30.1 APPROX EVERY TWO SECS. STATE VECTOR IS ALWAYS
# FOR THIS VEHICLE. V82 DOES NOT DISTURB STATE VECTOR. RESULTS
# OF SR30.1 ARE RAPO, RPER, HAPO, HPER, TPER, TFF.
# FLASH MONITOR V16N44 (HAPO, HPER, TFF).
# IF MODE IS P11, THEN CALL DELRSPL SO ASTRONAUT CAN MONITOR
# RESULTS BY N50E. SPLASH COMPUTATION DONE ONCE PER TWO SECS.
# ADDENDUM: HAPO AND HPER SHOULD BE CHANGED TO READ HAPOX AND HPERX IN THE
# ABOVE REMARKS.
#
# CALLING SEQUENCE: VERB 82 ENTER.
#
# SUBROUTINES CALLED: SR30.1, GOXDSPF
# MAYBE - THISPREC, OTHPREC, LOADTIME, DELRSPL
#
# NORMAL EXIT MODES: TC ENDEXT
#
# ALARMS: NONE
#
# OUTPUT: HAPOX (-29) M
# HPERX (-29) M
# RAPO (-29) M EARTH
# (-27) M MOON
## Page 506
# RPER (-29) M EARTH
# (-27) M MOON
# TFF (-28) CS CONTAINS NEGATIVE QUANTITY
# -TPER (-28) CS CONTAINS NEGATIVE QUANTITY
# RSP-RREC(-29) M IF DELRSPL CALLED
#
# ERASABLE INITIALIZATION REQUIRED: STATE VECTOR.
#
# DEBRIS: QPRET, RONE, VONE, TFF/RTMU, HPERMIN, RPADTEM, V82EMFLG.
# MAYBE: TSTART82, V82FLAGS, TDEC1.
EBANK= HAPOX
BANK 31
SETLOC R30LOC
BANK
COUNT* $$/R30
V82CALL TC INTPRET
BON GOTO
AVEGFLAG
V82GON # IF AVERAGE G ON
V82GOFF # IF AVERAGE G OFF
V82GOFF EXIT # ALLOW ASTRONAUT TO SELECT VEHICLE
CAF TWO # DESIRED FOR ORBITAL PARAMETERS
TS OPTIONX
CAF ONE
TS OPTIONX +1
CAF OPTIONVN # V 04 N 06
TC BANKCALL
CADR GOXDSPF
TC ENDEXT # TERMINATE
TC +2 # PROCEED
TC -5 # DATA IN. OPTIONX+1 = 1 FOR THIS VEHIC.
# UNEQ 1 FOR OTHER VEHICLE.
CAF BIT4 # 80 MS
TC WAITLIST
EBANK= TFF
2CADR TICKTEST
RELINT
V82GOFLP CAF TFFBANK # MAJOR RECYCLE LOOP ENTRY
TS EBANK
CAF ZERO
TS V82FLAGS # ZERO FLAGS FOR TICKTEST. INHIBITS
# DECREMENTING OF TFF AND -TPER.
CAF PRIO7
TC FINDVAC # V82GOFF1 WILL EXECUTE STATE VECTOR
## Page 507
EBANK= TFF # UPDATE AND ORBIT CALCULATIONS FOR
2CADR V82GOFF1 # SELECTED VEHICLE ABOUT PROPER BODY.
RELINT
V82STALL CAF THREE # STALL IN THIS LOOP AND WITHOLD V 16 N 44
MASK V82FLAGS # UNTIL STATE VECTOR UPDATE SETS ONE OF
CCS A # OUR FLAG BITS.
TC FLAGGON # EXIT FROM STALL LOOP.
CAF 1SEC
TC BANKCALL
CADR DELAYJOB
TC V82STALL
FLAGGON CAF V16N44 # MONITOR HAPO,HPER,TFF.
TC BANKCALL
CADR GOXDSPF
TC B5OFF # TERM THIS TELLS TICKTEST TO KILL ITSELF
TC B5OFF # PROCEED DITTO
TC V82GOFLP # RECYCLE RECOMPUTE STATE VECT + DISPLAY
OPTIONVN VN 0412
V16N44 VN 1644
TFFBANK ECADR TFF
V82GOFF1 TC INTPRET
RTB
LOADTIME
STORE TDEC1 # TIME FOR STATE VECTOR UPDATE.
STORE TSTART82 # TIME FOR INTERNAL USE.
EXIT
CS OPTIONX +1 # 1 FOR THIS VEHICLE, NOT 1 FOR OTHER
AD ONE
EXTEND
BZF THISSHIP
OTHSHIP TC INTPRET
CALL # CALL STATE VECTOR UPDATE FOR OTHER SHIP.
OTHPREC
BOTHSHIP VLOAD # MOVE RESULTS INTO TFFCONIC STORAGE AREAS
RATT # TO BE CALLED BY SR30.1.
STOVL RONE # RATT AT (-29)M FOR EARTH OR MOON
VATT
STORE VONE # VATT AT (-7)M/CS FOR EARTH OR MOON
DLOAD*
1/RTMUE,2 # X2 IS 0 FOR EARTH CENTERED STATE VEC
STORE TFF/RTMU # X2 IS 2 FOR MOON
DLOAD* # AS LEFT BY THISPREC OR OTHPREC.
MINPERE,2
STORE HPERMIN # TFFRTMU, HPERMIN AND RPADTEM ARE ALL
SLOAD BHIZ # EARTH/MOON PARAMETERS AS SET HERE.
## Page 508
X2
EARTHPAD
GOTO
MOONPAD
THISSHIP TC INTPRET
CALL # CALL STATE VECTOR UPDATE FOR THIS SHIP.
THISPREC
GOTO
BOTHSHIP
# THE FOLLOWING CONSTANTS ARE PAIRWISE INDEXED. DO NOT SEPARATE PAIRS.
1/RTMUM 2DEC* .45162595 E-4 B14*
1/RTMUE 2DEC* .50087529 E-5 B17*
MINPERM 2DEC 10668 B-27 # 35 KFT MIN PERIGEE HEIGHT FOR MOON(-27)M
MINPERE 2DEC 91440 B-29 # 300 KFT (-29)M FOR EARTH
EARTHPAD DLOAD CLRGO # PAD 37-B RADIUS. SCALED AT (-29)M.
RPAD
V82EMFLG # INDICATE EARTH SCALING FOR SR30.1
BOTHPAD
MOONPAD VLOAD ABVAL # COMPUTE MOON PAD RADIUS FROM RLS VECTOR.
RLS # SCALED AT (-27)M.
SET
V82EMFLG # INDICATE MOON SCALING FOR SR30.1
BOTHPAD STCALL RPADTEM
SR30.1 # CALCULATE ORBITAL PARAMETERS
EXIT
CA MODREG # ARE WE IN POO
EXTEND
BZF CANDEL # YES, DO DELRSPL
SPLRET1 TC INTPRET
RTB DSU
LOADTIME
TSTART82 # PRESENT TIME - TIME V82GOFF1 BEGAN
STORE TSTART82 # SAVE IT
DLOAD BZE # SR30.1 SETS -TPER=0 IF HPER L/
-TPER # HPERMIN (300 OR 35) KFT.
TICKTFF # (-TPER = 0)
TICKTPER DLOAD DAD # (-TPER NON ZERO) TFF WAS NOT COMPUTED,
-TPER # BUT WAS SET TO 59M59S. DONT TICK TFF, DO
TSTART82 # TICK -TPER. DISPLAY BOTH.
STORE -TPER # -TPER CORRECTED FOR TIME SINCE V82GOFF1
EXIT # BEGAN.
## Page 509
CAF BIT1
TS V82FLAGS # INFORMS TICKTEST TO INCREMENT ONLY -TPER
TC ENDOFJOB
TICKTFF DLOAD DAD # (-TPER=0) TFF WAS COMPUTED. TICK TFF.
TFF # DO NOT TICK -TPER. DISPLAY TFF, BUT NOT
TSTART82 # -TPER.
STORE TFF # TFF CORRECTED FOR TIME SINCE V82GOFF1
EXIT # BEGAN.
CAF BIT2
TS V82FLAGS # INFORMS TICKTEST TO INCREMENT ONLY TFF.
TC ENDOFJOB
TICKTEST CAF BIT5 # THIS WAITLIST PROGRAM PERPETUATES ITSELF
MASK EXTVBACT # ONCE A SEC UNTIL BIT 5 OF EXTVBACT =0.
CCS A
TC DOTICK
CAF PRIO25
TC NOVAC # TERMINATE V 82. CANT CALL ENDEXT IN RUPT.
EBANK= EXTVBACT
2CADR ENDEXT
TC TASKOVER
DOTICK CAF 1SEC # RE-REQUEST TICKTEST.
TC WAITLIST
EBANK= TFF
2CADR TICKTEST
CAF THREE
MASK V82FLAGS
INDEX A
TC +1
TC TASKOVER # IF NO FLAGBITS SET DONT CHANGE TFF OR
# -TPER, BUT CONTINUE LOOP.
TC TPERTICK # ONLY BIT 1 SET. INCR -TPER BY 1 SEC.
TFFTICK CAF 1SEC # ONLY BIT 2 SET. INCR TFF BY 1 SEC.
TS L
CAF ZERO
DAS TFF
TC TASKOVER
TPERTICK CAF 1SEC
TS L
CAF ZERO
DAS -TPER
TC TASKOVER
## Page 510
V82GON EXIT # AVERAGE G ON. USE CURRENT STATE VECTOR
# FOR ORBITAL PARAMETER CALCULATIONS.
CAF PRIO7 # LESS THAN LAMBERT
TC FINDVAC # V82GON1 WILL PERFORM ORBIT CALCULATIONS
EBANK= TFF # ABOUT PROPER BODY APPROX ONCE PER SEC.
2CADR V82GON1
RELINT
CCS NEWJOB # WITHOLD V16 N44 UNTIL FIRST ORBIT CALC
TC CHANG1 # IS DONE. NOTE: V82GON1 (PRIO7, FINDVAC
# JOB) IS COMPLETED BEFORE V82GON (PRIO7,
# NOVAC JOB).
V82REDSP CAF V16N44 # MONITOR HAPO, HPER, TFF
TC BANKCALL
CADR GOXDSPF
TC B5OFF # TERM THIS TELLS V82GON1 TO KILL ITSELF.
TC B5OFF # PROC DITTO.
TC V82REDSP # RECYCLE
V82GON1 TC INTPRET # THIS EXEC PROGRAM PERPETUATES ITSELF
# ONCE A SEC UNTIL BIT 5 OF EXTVBACT =0.
VLOAD GOTO # HOLDS OFF CCS NEWJOB BETWEEN RN AND
RN # VN FETCH SO RN, VN ARE FROM SAME
NEXTLINE # STATE VECTOR UPDATE.
NEXTLINE STOVL RONE # RN AT (-29)M FOR EARTH OR MOON
VN
STORE VONE # VN AT (-7)M/CS FOR EARTH OR MOON
BON GOTO
MOONTHIS # FLAG INDICATES BODY ABOUT WHICH ORBITAL
MOONGON # CALCULATIONS ARE TO BE PERFORMED.
EARTHGON # IF SET - MOON, IF RESET - EARTH.
MOONGON SET DLOAD
V82EMFLG # INDICATE MOON SCALING FOR SR30.1
1/RTMUM # LUNAR PARAMETERS LOADED HERE FOR SR30.1
STODL TFF/RTMU
MINPERM
STOVL HPERMIN
RLS # SCALED AT (-27)M.
ABVAL GOTO
V82GON2
EARTHGON CLEAR DLOAD
V82EMFLG # INDICATE EARTH SCALING FOR SR30.1
1/RTMUE # EARTH PARAMETERS LOADED HERE FOR SR30.1
STODL TFF/RTMU
MINPERE
STODL HPERMIN
RPAD
V82GON2 STCALL RPADTEM # COMMON CODE FOR EARTH & MOON.
SR30.1
## Page 511
EXIT
TC CHECKMM
DEC 11
TC V82GON3 # NOT IN MODE 11.
CANDEL TC INTPRET # IN MODE 11 OR 00
CALL
INTSTALL # DELRSPL DOES INTWAKE
DLOAD CALL
TFF
DELRSPL # RETURN IS TO NEXT LINE (SPLRET).
SPLRET EXIT
CA MODREG
EXTEND
BZF SPLRET1
V82GON3 CAF BIT5
MASK EXTVBACT # SEE IF ASTRONAUT HAS SIGNALLED TERMINATE
EXTEND
BZF ENDEXT # YES, TERMINATE VB 82 LOOP
CAF 1SEC
TC BANKCALL # WAIT ONE SECOND BEFORE REPEATING
CADR DELAYJOB # ORBITAL PARAMETER COMPUTATION.
TC V82GON1
## Page 512
# SUBROUTINE NAME: SR30.1
# MOD NO: 0 DATE: 16 FEB 67
# MOD BY: RR BAIRNSFATHER LOG SECTION: R32
# MOD NO: 1 MOD BY: RR BAIRNSFATHER DATE: 11 APR 67 SR30.1 CHANGED TO ALLOW MONITOR OPERN
# MOD NO: 2 MOD BY: RR BAIRNSFATHER DATE: 14 APR 67 ADD OVFL CK FOR RAPO
# MOD NO: 3 MOD BY ALONSO DATE: 11 DEC 67 SUBROUTINE REWRITTEN
# MOD NO: 4 MOD BY ALONSO DATE: 26 MAR 68 PROG MOD TO HANDLE DIF EARTH/MOON SCALE
# MOD NO: 5 MOD BY: RR BAIRNSFATHER DATE: 6 AUG 68 OVFL CK FOR HAPO & HPER. VOIDS MOD #2.
#
# NEW FUNCTIONAL DESCRIPTION: ORBITAL PARAMETERS DISPLAY FOR NOUNS 32 AND 44.
# SR30.1 CALLS TFFCONMU AND TFFRP/RA TO CALCULATE RPER (PERIGEE RADIUS),
# RAPO (APOGEE RADIUS), HPER (PERIGEE HEIGHT ABOVE LAUNCH PAD OR LUNAR
# LANDING SITE), HAPO (APOGEE HEIGHT AS ABOVE), TPER (TIME TO PERIGEE),
# TFF (TIME TO INTERSECT 300 KFT ABOVE PAD OR 35KFT ABOVE LANDING SITE).
# IF HPER IS GREATER THAN OR EQUAL TO HPERMIN, CALCULATES TPER AND STORES
# NEGATIVE IN -TPER. OTHERWISE STORES +0 IN -TPER. WHENEVER TPER IS
# CALCULATED, TFF IS NOT COMPUTABLE AND DEFAULTS TO -59MIN 59SEC. IF HAPO
# WOULD EXCEED 9999.9 NM, IT IS LIMITED TO THAT VALUE FOR DISPLAY.
#
# ADDENDUM: HAPO AND HPER SHOULD BE CHANGED TO READ HAPOX AND HPERX IN THE
# ABOVE REMARKS.
#
# CALLING SEQUENCE: CALL
# SR30.1
#
# SUBROUTINES CALLED: TFFCONMU, TFFRP/RA, CALCTPER, CALCTFF
#
# NORMAL EXIT MODE: CALLING LINE +1 (STILL IN INTERPRETIVE MODE)
#
# ALARMS: NONE
#
# OUTPUT: RAPO (-29) M EARTH APOGEE RADIUS EARTH CENTERED COORD.
# (-27) M MOON MOON CENTERED COORD.
# RPER (-29) M EARTH PERIGEE RADIUS EARTH CENTERED COORD.
# (-27) M MOON MOON CENTERED COORD.
# HAPOX (-29) M APOGEE ALTITUDE ABOVE PAD OR LAND. SITE MAX VALUE LIMITED TO 9999.9 NM.
# HPERX (-29) M PERIGEE ALT. ABOVE PAD OR LAND. SITE MAX VALUE LIMITED TO 9999.9 NM.
# TFF (-28) CS TIME TO 300KFT OR 35KFT ALTITUDE
# -TPER (-28) CS TIME TO PERIGEE
#
# ERASABLE INITIALIZATION REQUIRED -
# TFF/RTMU (+17) EARTH RECIPROCAL OF PROPER GRAV CONSTANT FOR
# (+14) MOON EARTH OR MOON = 1/SQRT(MU).
# RONE (-29) M STATE VECTOR
# VONE (-7) M/CS STATE VECTOR
# RPADTEM (-29) M EARTH RADIUS OF LAUNCH PAD OR LUNAR LANDING
# (-27) M MOON SITE.
# HPERMIN (-29) M EARTH (300 OR 35) KFT MINIMUM PERIGEE ALTITUDE
# (-27) M MOON ABOVE LAUNCH PAD OR LUNAR LANDING SITE.
# V82EMFLG (INT SW BIT) RESET FOR EARTH, SET FOR MOON.
#
# DEBRIS: QPRET, PDL, S2
## Page 513
COUNT* $$/SR30S
SR30.1 SETPD STQ # INITIALIZE PUSHDOWN LIST.
0
S2
# SR30.1 INPUT: RONE AT (-29)M EARTH/MOON
# VONE AT (-7)M/CS
# TFFCONMU, TFFRP/RA, CALCTPER AND CALCTFF
# CALLS REQUIRE:
# EARTH CENTERED (NO RESCALING REQUIRED)
# RONE SCALED TO B-29 M
# VONE SCALED TO B-7 M/CS
# MOON CENTERED (RESCALING REQUIRED)
# RONE SCALED TO B-27 M
# VONE SCALED TO B-5 M/CS
BOFF VLOAD
V82EMFLG # OFF FOR EARTH, ON FOR MOON.
TFFCALLS
RONE
VSL2
STOVL RONE
VONE
VSL2
STORE VONE
TFFCALLS CALL
TFFCONMU
CALL # TFFRP/RA COMPUTES RAPO,RPER.
TFFRP/RA
# RETURNS WITH RAPO IN D(MPAC).
DSU
RPADTEM
BOFF SR2R # NEED HAPO AT (-29)M FOR DISPLAY.
# IF MOON CENTERED, RESCALE FROM (-27)M.
# IF EARTH CENTERED ALREADY AT (-29)M.
V82EMFLG # OFF FOR EARTH , ON FOR MOON.
+1
CALL # IF HAPO > MAXNM, SET HAPO =9999.9 NM.
MAXCHK # OTHERWISE STORE (RAPO-RPADTEM) IN HAPO.
STORHAPO STODL HAPOX
RPER
DSU
RPADTEM # GIVES HPER AT (-29)M EARTH, (-27)M MOON.
STORE MPAC +4 # SAVE THIS FOR COMPARISON TO HPERMIN.
BOFF SR2R # NEED HPER AT (-29)M FOR DISPLAY.
# IF MOON CENTERED, RESCALE FROM (-27)M.
# IF EARTH CENTERED ALREADY AT (-29)M.
V82EMFLG # OFF FOR EARTH, ON FOR MOON.
+1
CALL # IF HPER > MAXNM, SET HPER = 9999.9 NM.
MAXCHK
## Page 514
STORHPER STODL HPERX # STORE (RPER - RPADTEM) INTO HPERX.
MPAC +4
DSU BPL # HPERMIN AT (-29)M FOR EARTH, (-27)M MOON
HPERMIN # IF HPER L/ HPERMIN (300 OR 35) KFT,
DOTPER # THEN ZERO INTO -TPER.
DLOAD GOTO # OTHERWISE CALCULATE TPER.
HI6ZEROS
SKIPTPER
DOTPER DLOAD CALL
RPER
CALCTPER
DCOMP # TPER IS PUT NEG INTO -TPER.
SKIPTPER STODL -TPER
HPERMIN # HPERMIN AT (-29)M FOR EARTH, (-27)M MOON
DAD CALL
RPADTEM # RPADTEM AT (-29)M FOR EARTH, (-27)M MOON
CALCTFF # GIVES 59M59S FOR TFF IF RPER G/
DCOMP # HPERMIN + RPADTEM. (TPER WAS NON ZERO)
STCALL TFF # OTHERWISE COMPUTES TFF. (GOTO)
S2
MAXCHK DSU BPL # IF C(MPAC) > 9999.9 NM, MPAC = 9999.9 NM
MAXNM
+3 # OTHERWISE C(MPAC) = B(MPAC).
DAD RVQ
MAXNM
+3 DLOAD RVQ # (USED BY P30 - P37 ALSO)
MAXNM
MAXNM 2OCT 0106505603
## Page 515
## There is no source code on this page — RSB 2004