https://github.com/virtualagc/virtualagc
Revision 4e5d304eb7cd5589b924ffb8b423b6f15511b35d authored by Ron Burkey on 20 October 2018, 17:47:00 UTC, committed by Ron Burkey on 20 October 2018, 17:47:00 UTC
the recently-added documents about YUL, was transcribed. Because the original program contained a deliberate error in YUL (as well as some constructs that have unintentionally become errors in yaYUL), I've provided it in two forms: TRIVIUM (which matches the original scan, to the extent feasible) and TRIVIUM-repaired (which has the deliberate and unintentional errors fixed, but otherwise retains the identical functionality of the original).
1 parent c6c292e
Tip revision: 4e5d304eb7cd5589b924ffb8b423b6f15511b35d authored by Ron Burkey on 20 October 2018, 17:47:00 UTC
The sample Block I AGC program TRIVIUM, found at the very end of one of
The sample Block I AGC program TRIVIUM, found at the very end of one of
Tip revision: 4e5d304
ORBITAL_INTEGRATION_PROGRAM.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: ORBITAL_INTEGRATION_PROGRAM.agc
## Purpose: Part of the source code for Solarium build 55. This
## is for the Command Module's (CM) Apollo Guidance
## Computer (AGC), for Apollo 6.
## Assembler: yaYUL --block1
## Contact: Jim Lawton <jim DOT lawton AT gmail DOT com>
## Website: www.ibiblio.org/apollo/index.html
## Page Scans: www.ibiblio.org/apollo/ScansForConversion/Solarium055/
## Mod history: 2009-09-22 JL Created.
## 2016-08-20 RSB Typos.
## 2016-12-28 RSB Proofed comment text using octopus/ProoferComments,
## and fixed errors found.
## Page 296
BANK 23
# *** SCALING FACTORS AND ARGUMENTS ***
DEL = 2
DEL+E = 2
2DEL = 4
2DEL+E = 4
E = 0
RSCALE = 16D
VSCALE = 6
TSCALE = 27D
2VSCALE = 12D
4RSCALE = 64D
R+VSCALE = 22D
# FBR3 SETS UP A TIMESTEP CALL TO KEPLER.
FBR3 TSRT 1
ROUND DAD
H
TSCALE -18D
TC
STORE TAU
DMP 2
TSRT ROUND
DAD
EARTHTAB
DT/2
12D
TET
STORE TET
ITC 0
KEPLER
ITC 0
KEPLER2
GETKTIME ITC 0
KTIMEN+1
ITC 0
KEPLER3
## Page 297
# THIS ORBITAL KEPLER SUBROUTINE FINDS THE POSITION AND VELOCITY OF THE VEHICLE AFTER TIME FOUND IN
# GIVENT SINCE RECTIFICATION TO POSITION RRECT AND VELOCITY VRECT . THE RESULTING POSITION AND VELOCITY ARE
# LEFT IN FOUNDR AND FOUNDV , RESPECTIVELY.
KEPLER LXA,1 1 # UNIT OF RECTIFICATION POSITION TO 0
SXA,1 UNIT
FIXLOC
PUSHLOC
RRECT
TSLT 0 # AND LENGTH OF ORIGINAL IN 6.
30D
1
VSQ 3 # A4 TO REGISTER 8.
ROUND DMP
TSLT DSU
TSLT ROUND
VRECT
6 # LENGTH OF POSITION AT RECTIFICATION.
2DEL+E -1
DP1/2
1
NOLOD 3 # ALPHA TO REGISTER 10.
TSRT COMP
DAD TSRT
DDV
1
DP1/2
2DEL+E -1
6
DOT 1 # A1 TO REGISTER 12.
TSLT ROUND
RRECT
VRECT
DEL+E
ITCQ 0
## Page 298
KEPLER2 UNIT 1
AXT,2 DOT
RCV
10D # SET MAXIMUM ITERATION COUNT TO 10.
VCV # IR/2 . VC IN 14
TSLT 0
30D
1
STORE ALPHAM # RC IN ALPHAM.
TSRT 1
ROUND DDV
DT/2
TSCALE -18D
ALPHAM # Q IN 16.
TSRT 4
DDV DSU
DMPR DMPR
DMPR AST,2
TSLT
DP1/2
2DEL+E -1
ALPHAM
10D # 1/4RC - ALPHA
16D # Q ( )
16D # Q Q ( )
DP1/3
1
2DEL +4
DMPR 1
TSLT
14D
16D
DEL +3
NOLOD 4
BDSU DMPR
BDSU DSU
DMP TSLT
ROUND DAD
DP1/2
- # 20
DP1/2
- # 18
- # 16
1
XKEP
## Page 299
STORE XKEP
ITCQ 0
## Page 300
# ITERATING EQUATIONS - GIVEN X IN MPAC AND 14D, FIND TIME OF FLIGHT.
KTIMEN+1 NOLOD 5 # FORM ALPHA X-SQUARED AND CALL S AND C.
DSQ ROUND
DMP TSLT
ROUND LXA,1 # AND SET PD INDICATOR TO 16 AS WELL.
INCR,1 SXA,1
ITA ITC
10D # ALPHA
2DEL
FIXLOC
16D
PUSHLOC
GMODE
S(X)C(X)
NOLOD 4 # S RETURNS IN MPAC, C ON TOP OF PDL.
DMP TSLT
DMP TSLT
DMP TSLT
ROUND
XKEP
4
XKEP
E +1
XKEP
1
STORE 23D # A3.
NOLOD 1
DMPR
8D
DMP 2
TSLT DMP
TSLT ROUND
XKEP
16D # VALUE OF C.
5
XKEP
E +2
STORE 21D # A2.
NOLOD 2
DMP TSRT
ROUND DAD
12D # A1.
2
## Page 301
DMPR 1
DAD
6
XKEP # COMPUTED TIME TO PD+18.
ITCI 0
GMODE
KEPLER3 NOLOD 1 # COMPARE COMPUTED TIME WITH GIVEN TIME.
BDSU
GIVENT
STORE 16D # DIFFERENCE TO REGISTER 16.
EXIT 0 # FOR DUMP ONLY **************
DUMPDUMP TC INTPRET
NOLOD 3
ABS DSU
BMN TIX,2
ITC
KEPSILON # SEE IF WITHIN EPSILON OF GIVEN TIME.
GETRANDV # IF SO, GET R AND V AND EXIT.
GETNEWX
GETRANDV
GETNEWX DMP 4
TSLT ROUND
BDSU DMP
AXC,1 TSLT*
ROUND
10D # ALPHA
23D # A3
2DEL+E
XKEP
12D # A1
E -3
0,1
STORE 18D
DMP 2
TSLT ROUND
DAD DAD
21D # A2
8D # A4
1
-
6 # R0
DDV 1
## Page 302
DAD
16D
18D
XKEP
STORE XKEP
ITC 0
GETKTIME
## Page 303
# CONSTANTS.
KEPSILON OCT 00000
OCT 00002
THREE/8 2DEC .375
DP1/4 2DEC .25
DP1/3 2DEC .333333333
DQUARTER EQUALS DP1/4
POS1/16 2DEC .0625
POS1/4 EQUALS DP1/4
3/8 EQUALS THREE/8
## Page 304
# SUBROUTINE FOR COMPUTING THE UNIVERSAL CONIC FUNCTIONS S(X) AND C(X). THE ACTUAL OUTPUT OF THIS ROUTINE
# CONSISTS OF SCALED VERSIONS DEFINED AS FOLLOWS:
#
# S (X) = S(64X) C (X) = C(64X)/4
# S S
#
# IT IS ASSUMED THAT THE INPUT ARRIVES IN MPAC,MPAC+1, AND THAT IT LIES BETWEEN -30/64 AND 40/64. UPON
# EXIT, S(X) WILL BE LEFT IN MPAC,MPAC+1 AND C(X) ON TOP OF THE PUSHDOWN LIST.
S(X)C(X) NOLOD 0 # SAVE ARGUMENT
STORE XSTOREX
NOLOD 2 # 2
RTB DSQ # COMPUTE A (X)
ROUND
A(X)
STORE ASQ
NOLOD 3 # 2 2
DMP TSLT # C (X)=A (.25 - 2XA ) TO PUSHDOWN LIST
ROUND BDSU # S
DMPR
XSTOREX
1
POS1/4
ASQ
TSRT 1 # 2
ROUND # A /4 TO PUSHDOWN LIST
ASQ
2
DMOVE 2 # 2
RTB DSQ # B TO PUSHDOWN LIST
ROUND
XSTOREX
B(X)
DMPR 2 # 2 2 2
BDSU DMPR # LEAVE S (X)=B (.0625-A X)+A /4 IN MPAC
DAD ITCQ # S
XSTOREX
ASQ
POS1/16
XSTOREX = 26D
ASQ = 24D
OCT 70707 # THIS HAS TO BE NEGATIVE TO TERMINATE EQN
## Page 305
A(X) TC POLY # A AND B POLYNOMIALS WHOSE COEFFICI-
DEC 10 # ENTS WERE OBTAINED WITH THE *AUTO-
2DEC 7.071067810 E-1 # CURVEFIT* PROGRAM
2DEC -4.714045180 E-1
2DEC 9.42808914 E-2
2DEC -8.9791893 E-3
2DEC 4.989987 E-4
2DEC -1.79357 E-5
TC DANZIG # RE-ENTER INTERPRETER
B(X) TC POLY
DEC 10
2DEC 8.164965793 E-1
2DEC -3.265986572 E-1
2DEC 5.90988980 E-2
2DEC -4.0085592 E-3
2DEC 2.781528 E-4
2DEC -1.25610 E-5
TC DANZIG # RETURN AS BEFORE
## Page 306
# ROUTINE FOR OBTAINING R AND V, NOW THAT THE PROPER X HAS BEEN FOUND.
GETRANDV LXA,1 2
INCR,1 SXA,1
COMP VXSC
FIXLOC
25D
PUSHLOC
21D # AZ FROM LAST ITERATION.
0 # UNIT OF GIVEN POSITION VECTOR.
DSU 2
TSLT VXSC
VAD VSLT
18D # LAST VALUE OF T.
23D # LAST VALUE OF A3.
DEL +1
VRECT
-
1
NOLOD 1 # ADDITION MUST BE DONE IN THIS ORDER.
VAD VAD
RRECT
STORE FOUNDR # RESULTING CONIC POSITION.
NOLOD 1 # LENGTH OF ABOVE TO PD+16.
ABVAL TSLT
1
STORE 16D
DMP 4
TSLT ROUND
DSU TSRT
DDV VXSC
VSLT
10D # ALPHA.
23D # A3
2DEL+E
XKEP
DEL+E
16D # LENGTH OF FOUND POSITION.
0 # UNIT OF RECTIFICATION POSITION.
3
TSRT 3
DSU DDV
VXSC VAD
VSLT
## Page 307
16D
1
21D
16D
VRECT
-
1
STORE FOUNDV # THIS COMPLETES THE CALCULATION.
ITCI 0
HBRANCH
## Page 308
# THE POSTRUE ROUTINES SET UP THE BETA VECTOR AND OTHER INITIAL CONDITIONS FOR THE NEXT ACCOMP.
POSTRUE LXA,1 3
SXA,1 VSRT
VAD LXA,2
LXA,1 SXA,1
SCALDELT # SETS UP SCALE A.
SCALEA
ALPHAV
RSCALE -4
RCV # POSITION OUTPUT OF KEPLER.
DIFEQCNT
SCALER
SCALEB # SET UP SCALE B AND G MODE.
STORE BETAV
BHIZ 0
WMATFLAG # TEST W MATRIX FLAG.
ACCOMP
VMOVE 0
BETAV
STORE VECTAB,2 # SAVE R/PV IN VECTAB FOR W MATRIX UPDATE.
## Page 309
# AGC ROUTINE TO COMPUTE ACCELERATION COMPONENTS.
ACCOMP UNIT 0 # UNITIZE ALPHA VECTOR
ALPHAV
STORE ALPHAV
DMOVE 0 # SAVE LENGTH OF ALPHA VECTOR
30D
STORE ALPHAM
STZ 0
OVFIND
ACCOMP2 VSRT 3 # 2
VSQ LXA,1 # NORMED B TO PD.
SXA,1 TSLC
ROUND
BETAV
1
FIXLOC
PUSHLOC
S1
TSLC 1 # NORMALIZE (LESS ONE) LENGTH OF ALPHA
TSRT # SAVING NORM. SCALE FACTOR IN X1
ALPHAM
X1
1 # C(PDL+2)= ALMOST NORMED ALPHAM
UNIT 0 # SAME PROCEDURE FOR BETA VECTOR
BETAV
STORE BETAV
DMOVE 0
30D
STORE BETAM
NOLOD 2
TSLC BDDV # FORM NORMALIZED QUOTIENT ALPHAM/BETAM
TSRT ROUND
X2
-
1 # C(PDL +2) = ALMOST NORMALIZED RHO.
## Page 310
LXC,2 3 # C(X2) = -SCALE(RHO) + 1.
XAD,2 XAD,2 # = -S(B)-N(B)+S(A)+N(A)+1
XSU,2 INCR,2
NOLOD TSRT*
X2
SCALEA
X1
SCALEB
2
0,2
NOLOD 1 # RHO/4 PD +6
TSRT ROUND
2
DOT 2
TSLT ROUND # (RHO/4)- 2 (ALPHAV/2.BETAV/2)
BDSU # TO PDL +6
ALPHAV
BETAV
1
NOLOD 1 # Q/4 = RHO(C(PDL +4)) TO PD +8D
DMPR
4
NOLOD 1 # (Q + 1)/4 TO PD +10D.
DAD
DQUARTER
NOLOD 1 # 3/2
SQRT DMPR # ((Q + 1)/4) TO PD +12D.
10D
NOLOD 1 # 3/2
TSLT DAD # (1/4) + 2((Q + 1)/4) TO PD +14D.
1
DQUARTER
## Page 311
DAD 3 # -
DMPR TSLT # (G/2)(C(PD +4))B/2 TO PD +16D.
DAD DDV
DMPR VXSC
10D
DP1/2
8D
1
THREE/8
14D
6
BETAV
VSRT 1 # A12 + C(PD +16D) TO PD +16D.
VAD
ALPHAV
3
DMP 5 # -
TSLC ROUND # GAMMA TO PD +22D, -SCALE(GAMMA)-1 TO
BDDV LXC,1 # X1.
XAD,1 XAD,1
XAD,1 XAD,1
COMP VXSC
0
12D
S2
2
X2 # C(X2) = SCALE (RHO).
S2 # C(S2) = N((B.B/4)(...)3/2)
S1 # C(S1) = N(B.B/4)
SCALEB
SCALEB
16D # RESULT OF PRECEDING EQUATION.
NOLOD 1 # -SCALE(GAMMA)-1 IS LEFT IN X1.
VSLT* # ADJUST GAMMA TO SCALE OF -32.
31D,1
STORE FV
VMOVE 0
BETAV
STORE ALPHAV # BETA VECTOR INTO ALPHA FOR NEXT ACCOMP.
DMOVE 0
BETAM
STORE ALPHAM
## Page 312
# THE OBLATE ROUTINE COMPUTES THE ACCELERATION DUE THE THE EARTHS OBLATENESS. IT USES THE UNIT OF THE
# VEHICLE POSITION VECTOR FOUND IN ALPHAV AND THE DISTANCE TO THE CENTER OF THE EARTH IN ALPHAM. THIS IS ADDED TO
# THE SUM OF THE DISTURBING ACCELERATIONS IN FV AND THE PROPER DIFEQ STAGE IS CALLED VIA X1.
OBLATE LXA,1 1
SXA,1 TSLT
FIXLOC # SET PUSH-DOWN COUNTER TO ZERO.
PUSHLOC
ALPHAM
1
STORE ALPHAM
DMPR 0 # P2'/8 TO REGISTER 0.
ALPHAV +4 # Z COMPONENT OF POSITION IS COS PHI.
3/4
DSQ 2 # P3'/4 TO REGISTER 2.
TSLT DMPR
DSU
ALPHAV +4
3
15/16
3/8
NOLOD 2 # P4'/16 TO REGISTER 4.
DMPR DMPR
TSLT
ALPHAV +4
7/12
1 # TO STACK.
DMPR 1 # FINISH P4'/16.
BDSU
P2'/8
2/3
NOLOD 1 # BEGIN COMPUTING P5'/128.
DMPR DMPR
ALPHAV +4
9/16
## Page 313
DMPR 6 # FINISH P5'/128 AND TERM USING UNIT
BDSU DMP # POSITION VECTOR AT ALPHA.
TSLT TSRT
DDV DAD
DMPR TSRT
DDV DAD
VXSC
P3'/4
5/128
-
J4REQ/J3
2
RSCALE -14D
ALPHAM
P4'/16
2J3RE/J2
RSCALE -14D
ALPHAM
P3'/4
ALPHAV
STORE ALPHAV
DMP 2 # COMPUTE TERM USING IZ.
TSLT TSRT
DDV DAD
J4REQ/J3
-
1
RSCALE -14D
ALPHAM
## Page 314
TSRT 2
DMPR DDV
DAD BDSU
2J3RE/J2
RSCALE -11D
-
ALPHAM
-
ALPHAV +4
STORE ALPHAV +4
DSQ 4
DSQ TSLC
BDDV VXSC
INCR,1 VSLT* # SHIFTS LEFT ON+, RIGHT ON -.
VAD
ALPHAM
X1
J2REQSQ
ALPHAV
4RSCALE -52D
0,1
FV
STORE FV
## Page 315
# THE DRAG ROUTINE IS AN INSERTION TO THE OBLATE ROUTINE. IT USES
# THE VEHICLE POSITION VECTOR FOUND IN RCV. THE DISTANCE TO THE CENTER OF
# THE EARTH IN ALPHAM, AND THE VEHICLE VELOCITY VECTOR IN VCV.
#
# IT APPROXIMATES THE U.S. STD ATMOSPHERE 1962 (OVER THE RANGE OF
# 100 TO 300 KM ABOVE SEA LEVEL) WITH AN EQUATION OF THE FORM
# 2 3 4 4
# RHO = BASERHO /((1 +C1 X +C2 X +C3 X +C4 X ) ).
#
# IT ASSUMES THE VEHICLE MASS TO BE THAT EXPECTED AFTER THE
# FIFTH SPS BURN.
DENSITY TSRT 2 # IF THE ALTITUDE IS GREATER THAN THE
DSU BPL # CEILING ALTITUDE, DENCEIL (300 KM),
ITC # SKIP THE DRAG CALCULATIONS AND GO
DENCEIL # TO NBRANCH.
RSCALE -14D
ALPHAM
DENSITY1
NBRANCH
DENSITY1 TSRT 2 # NORMALIZE ALTITUDE FOR AIR DENSITY
BDSU TSLT # FUNCTION SO THAT IT RANGES FROM
DDV TSLT # 0 TO 1 OVER THE ALTITUDES OF 100 KM
DENBASE # TO 300 KM RELATIVE TO THE REFERENCE
RSCALE -14D # SPHERE AND STORE IN DENALT.
ALPHAM
6
DENFACT
RSCALE -14D
STORE DENALT
DRAG1 NOLOD 7 # CALCULATE SCALAR PART OF DRAG, I.E.,
DMP DAD # ((RHO)(AREA)(DRAG COEFF))/MASS.
DMP DAD
DMP DAD # LEAVE IN PDL AS D. P. NUMBER
DMP DAD
TSLT DSQ
DSQ TSLT
BDDV
DEN4
DEN3
DENALT
DEN2
DENALT
DEN1
DENALT
DEN0
1
## Page 316
2
PACD/M
DRAG2 VXV 2
AXT,1 VSLT*
VSU
OMEGA
RCV
23D
R+VSCALE,1
VCV
NOLOD 3
ABVAL VXSC
VXSC AXT,1
VSLT* VAD
- # (-1/2)(ABVAL(-V))(V)
- # - -
1 # (-1/2)(RHO A CD/M)(ABVAL(-V))(V)
2VSCALE -12D,1
FV
STORE FV # SUM OF PERTURB ACCELERATIONS
NBRANCH LXA,1 1
ITC*
DIFEQCNT
DIFEQ,1
## Page 317
# BEGIN INTEGRATION STEP WITH RECTIFICATION TEST.
TIMESTEP ABVAL 2 # RECTIFICATION REQUIRED IF THE LENGTH OF
DSU BMN # DELTA IS GREATER THAN .5 (8 KM).
ITC
YV
DP1/4
INTGRATE
RECTIFY # CALL RECTIFICATION SUBROUTINE.
INTGRATE AXT,1 3 # INITIALIZE INDEXES AND SWITCHES.
SXA,1 AXT,1
SXA,1 TEST
SWITCH
FBR3
FBRANCH # EXIT FROM DIFEQCOM
POSTRUE
HBRANCH # EXIT FROM KEPLER.
JSWITCH # 0 FOR STATE VECTOR, 1 FOR W MATRIX.
+2 # TURN IT OFF HERE.
JSWITCH
## Page 318
DIFEQ0 VMOVE 0 # POSITION DEVIATION INTO ALPHA.
YV
STORE ALPHAV
DMOVE 0 # START H AT 0.
DPZERO
STORE H # GOES 0(DELT/2)DELT.
NOLOD 0 # ZERO DIFEQCNT AND REGISTER FOLLOWING.
STORE DIFEQCNT # GOES 0(-12D)(-24D).
ITCI 0 # BEGIN AT ADDRESS IN HBRANCH.
HBRANCH
## Page 319
# THE RECTIFY SUBROUTINE IS CALLED BY THE INTEGRATION PROGRAM (AND OCCASIONALLY BY THE MEASUREMENT
# INCORPORATION ROUTINES) TO ESTABLISH A NEW CONIC.
RECTIFY VSRT 1 # RECTIFY - FORM TOTAL POSITION AND VEL.
VAD # ADJUST SCALE DIFFERENCE (ASSUMED
TDELTAV
RSCALE -4
RCV
STORE RRECT
NOLOD 0 # SET UP CONIC 'ANSWER' FOR TIMESTEP.
STORE RCV
AXT,1 2
VMOVE VSLT*
VAD
VSCALE -14D
TNUV
0,1
VCV
STORE VRECT
NOLOD 0
STORE VCV
AXT,1 1 # ZERO DELTA, NU, AND TIME SINCE RECTIFI-
AST,1 DMOVE
12D
2
DPZERO
STORE TC
NOLOD 0
STORE XKEP # ZERO X.
ZEROLOOP NOLOD 0 # INDEXES CAUSE LOOP TO ZERO 6 CONSECUTIVE
STORE YV +12D,1 # DP NUMBERS (DELTA AND NU ARE ADJACENT).
TIX,1 1 # LOOP OR START INTEGRATION STEP IF DONE.
ITCQ
ZEROLOOP
## Page 320
# THE THREE DIFEQ ROUTINES - DIFEQ+0, DIFEQ+12, AND DIFEQ+24 - ARE ENTERED TO PROCESS THE CONTRIBUTIONS
# AT THE BEGINNING, MIDDLE, AND END OF THE TIME STEP, RESPECTIVELY. THE UPDATING IS DONE BY THE NYSTROM METHOD.
DIFEQ+0 VSRT 0
FV
3
STORE PHIV
ITC 0
DIFEQCOM
7/12 2DEC .5833333333 # ENTRIES MUST BE 12 WORDS APART SO FILL
9/16 2DEC 9 B-4 # HOLES WITH CONSTANTS
5/128 2DEC 5 B-7
DIFEQ+12 VSRT 1
VAD
FV
1
PHIV
STORE PSIV
ITC 0
DIFEQCOM -6
DPZERO 2DEC 0.0
DP2/3 2DEC .6666666667
DIFEQ+24 VXSC 3 # DO FINAL CALCULATION FOR Y AND Z.
VXSC VSLT
VAD VXSC
VAD
PHIV
H
DP2/3
1
ZV
H
YV
STORE YV
## Page 321
VSRT 4
VAD VXSC
VXSC VSLT
VAD TEST # SEE IF THIS IS STATE VECTOR OR W COLUMN.
AXT,1
FV
3
PSIV
H
DP2/3
1
ZV
JSWITCH
ENDSTATE
0
STORE W +72D,2 # VELOCITY COLUMN VECTOR.
VMOVE 0
YV
STORE W +36D,2 # POSITION COLUMN VECTOR.
TIX,2 0
NEXTCOL
VMOVE 0
DELTAV
STORE TDELTAV
VMOVE 0
NUV
STORE TNUV
ITCI 0
STEPEXIT
NEXTCOL VMOVE* 0 # SET UP NEXT COLUMNS OF W MATRIX.
W +36D,2
STORE YV
VMOVE* 0
W +72D,2
STORE ZV
ITC 0
DIFEQ0
ENDSTATE NOLOD 0
STORE TNUV
## Page 322
TSRT 1 # UPDATE TIME SINCE RECTIFICATION.
ROUND DAD
H
TSCALE -18D
TC
STORE TC
BHIZ 0
WMATFLAG
NEXTCOL -2
ITC 0
SETWINT # FOR NOW
SETWINT AXT,2 4 # SET UP W MATRIX EXTRAPOLATION ROUTINES.
AST,2 AXT,1 # PROGRAM DESCRIPTION IS AT DOW.. .
SXA,1 SXA,1
SWITCH AXT,1
ITC
36D
6
DOW..
FBRANCH
HBRANCH
JSWITCH
0
NEXTCOL
## Page 323
# COMES HERE TO FINISH FIRST TWO DIFEQ COMPUTATIONS.
-6 VSRT 1 # ENTERS HERE FROM DIFEQ+12 MIDPOINT
VAD # COMPUTATION.
FV
2
PHIV
STORE PHIV
DIFEQCOM DAD 1 # INCREMENT H AND DIFEQCNT.
INCR,1 SXA,1
DT/2
H
-12D
DIFEQCNT # DIFEQCNT SET FOR NEXT ENTRY.
STORE H
VXSC 2
VSRT VAD
VXSC VAD
FV
H
1
ZV
H
YV
STORE ALPHAV
ITCI 0 # EXIT VIA FBRANCH.
FBRANCH
DIFEQ EQUALS DIFEQ+0
## Page 324
# ORBITAL ROUTINE FOR EXTRAPOLATING THE W MATRIX. IT COMPUTES THE
# SECOND DERIVATIVE OF EACH COLUMN POSITION VECTOR OF THE MATRIX AND CALLS
# THE NYSTOM INTEGRATION ROUTINES TO SOLVE THE DIFFERENTIAL EQUATIONS. THE
# PROGRAM USES A TABLE OF VEHICLE POSITION VECTORS COMPUTED DURING THE
# INTEGRATION OF THE VEHICLES POSITION AND VELOCITY.
DOW.. VSRT 0
ALPHAV
4
UNIT* 2 # X1 REFERENCES THE TABLE OF POSITION
VPROJ VXSC # VECTORS AND CALLS THE CORRECT DIFEQ PROG
VSU
VECTAB,1
ALPHAV
3/4
DMP 4 # CUBE OF LENGTH OF POSITION VECTOR
TSLC ROUND # DIVIDES VECTOR IN PUSH-DOWN LIST TO
BDDV VXSC # FORM FINAL RESULT.
XCHX,2 INCR,2 # INCREMENT COMPENSATES FOR .5 R IN 30D.
VSLT* LXA,2
28D
30D
S1
DP1/4
-
S1
3
0,2
S1
STORE FV
ITC* 0 # CALL NYSTROM ROUTINES ACCORDING TO X1.
DIFEQ,1
## Page 325
EARTHTAB 2DEC .6335627 # 400 / SQRT(MU).
15/16 2DEC 15. B-4
3/4 2DEC 3.0 B-2
J2REQSQ 2DEC .335914874
2J3RE/J2 2DEC -.003309146
J4REQ/J3 2DEC .60932709
2/3 EQUALS DP2/3
P2'/8 EQUALS 0
P3'/4 EQUALS 2
P4'/16 EQUALS 4
DP1/2 2DEC .5
DENBASE 2DEC 6455 B-14 # EARTHRAD +100 KM SCALED AT 2 TO THE (14)
DENFACT 2DEC 0.781250 # 200/256
DEN4 2DEC -7.55161127 B-5 # CONSTANTS FOR DENSITY FUNCTION SCALED AT
DEN3 2DEC 21.2523654 B-5 # 2 TO THE (5)
DEN2 2DEC -19.9253572 B-5
DEN1 2DEC 16.0533069 B-5
DEN0 2DEC 1.0 B-5
PACD/M 2DEC 0.0000363648 # (RHO AREA CD)/MASS AT 100KM
OMEGA 2DEC 0 # EARTH ROT VECTOR/SQRT(MU) SCALED
2DEC 0 # AT 2 TO THE (-23) KM TO (-3/2)
2DEC 0.968892208
DENALT = 26D # TEMPORARY STORAGE FOR ALTITUDE
DENCEIL 2DEC 6655 B-14 # EARTHRAD +300 KM SCALED AT 2(14)
Computing file changes ...
