Revision c889f392c435278e913bd6f00367bf3fea9327ba authored by Mike Stewart on 28 July 2019, 00:48:04 UTC, committed by Mike Stewart on 28 July 2019, 00:48:04 UTC
LANDING_ANALOG_DISPLAYS.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: LANDING_ANALOG_DISPLAYS.agc
## Purpose: A log section of Zerlina 56, the final revision of
## Don Eyles's offline development program for the variable
## guidance period servicer. It also includes a new P66 with LPD
## (Landing Point Designator) capability, based on an idea of John
## Young's. Neither of these advanced features were actually flown,
## but Zerlina was also the birthplace of other big improvements to
## Luminary including the terrain model and new (Luminary 1E)
## analog display programs. Zerlina was branched off of Luminary 145,
## and revision 56 includes all changes up to and including Luminary
## 183. It is therefore quite close to the Apollo 14 program,
## Luminary 178, where not modified with new features.
## Reference: pp. 890-898
## Assembler: yaYUL
## Contact: Ron Burkey <info@sandroid.org>.
## Website: www.ibiblio.org/apollo/index.html
## Mod history: 2017-07-28 MAS Created from Luminary 210.
## 2017-08-19 MAS Updated for Zerlina 56.
## Page 890
# ****************************************************************************************************************
# LANADISP: DISPLAY INERTIAL DATA ROUTINE FOR DESCENT AND ABORTS THIS VERSION BY EYLES
# ****************************************************************************************************************
BANK 21
SETLOC R10
BANK
EBANK= END-E7
COUNT* $$/R10
# ************************************************************************
# COMPUTE ALTITUDE AND ALTITUDE-RATE
# ************************************************************************
LANADISP CA RUNITX # COMPUTE RADIAL VELOCITY
EXTEND
MP VVECTX
DXCH ALTRATE
CA RUNITX # COMPUTE THE MORE SENSITIVE TERM IN DP
EXTEND
MP VVECTX +1
TS L
CAF ZERO
DAS ALTRATE
CA RUNITY # NOTE: WITH NORMAL DESCENT IMU ALIGNMENT
EXTEND # THIS TERM IS ALWAYS ZERO, BUT ALTRATE
MP VVECTY # CAN BE DISPLAYED DURING ASCENT TOO
DAS ALTRATE
CA RUNITZ
EXTEND
MP VVECTZ
DAS ALTRATE
CA DALTRATE # COMPENSATE FOR CHANGE IN DIRECTION OF R
EXTEND
MP DT
DAS ALTRATE # ALTRATE IN UNITS OF 2(5) M/CS
EXTEND
DCA ALTRATE
DXCH ALTRTEMP
EXTEND
DCA HDOTLAD
DAS ALTRTEMP # AVERAGE ALTRATE IN UNITS OF 2(4) M/CS
# THE FOLLOWING COMPUTATION FAILS IF DT EXCEEDS 20.47 SECONDS (UNLIKELY).
CA DT
EXTEND
## Page 891
MP BIT4
CA L # FETCH DT FROM L IN UNITS OF 2(11) CS
EXTEND
MP ALTRTEMP
DXCH ALTITUDE
EXTEND
DCA HCALCLAD
DAS ALTITUDE # ALTITUDE IN UNITS OF 2(15) METERS
# ************************************************************************
# SEND OUT ALTITUDE-RATE IF POSSIBLE
# ************************************************************************
LANACONT CAF BIT6 # IS THE METER MODE SWITCH IN PGNCS?
EXTEND
RAND CHAN30
CCS A
TCF DISPRSET # NO: GO RESET
CS FLAGWRD1 # YES: IS INITIALIZATION IN ORDER?
MASK DIDFLBIT
CCS A
TCF DISPINIT # YES: THEN GO DO IT
CAF BIT2 # NO: ARE RR ERROR COUNTERS ENABLED?
EXTEND
RAND CHAN12
EXTEND
BZF DISPRSET # NO: REINITIALIZE DISPLAYS
ALTRROUT EXTEND # YES: SIGNIFY ALTITUDE-RATE (BIT2 IN A)
WOR CHAN14
EXTEND
DCA ALTRATE
DDOUBL # RESCALE ALTRATE TO UNITS OF 2(2) M/CS
DDOUBL
DDOUBL
EXTEND
MP ALTRCONV # RESCALE TO UNITS OF .5 F/S/BIT
XCH L # ROUND TO NEAREST .5 F/S
DOUBLE
TS Q
CAF ZERO
ADS L
AD NEGMAX
TS L
TCF +3
## Page 892
AD L
COM
+3 XCH ALTM
CAF BIT3
EXTEND
WOR CHAN14
CA TWELVE # PAUSE 12 CS FOR ALTRATE TO BE READ OUT
TC VARDELAY # (MUST BE > 100 MS TO WORK ON THE LMS)
ALTROUT CS BIT2 # SIGNIFY ALTITUDE
EXTEND
WAND CHAN14
CA ALTITUDE +1
EXTEND
MP ALTCONV
TS L
CAF ZERO
DXCH ALTTEMP
CA ALTITUDE
EXTEND
MP ALTCONV
DAS ALTTEMP # ALTITUDE IN UNITS OF 9.380 FEET/BIT
DXCH ALTTEMP
DDOUBL
DDOUBL # RESCALE TO UNITS OF 2.345 FEET/BIT
OVSK
TCF +4 # NO OVERFLOW: -38420 < ALTITUDE < +38420
MASK POSMAX # RESET OVERFLOW
AD BIT15
TCF +5
+4 CCS A # APPLY LOWER LIMIT OF POSITIVE ZERO
AD ONE
TCF +2
CAF ZERO
+5 XCH ALTM
CAF BIT3
EXTEND
WOR CHAN14
# ************************************************************************
# SEND OUT FORWARD AND LATERAL VELOCITIES
# ************************************************************************
## Page 893
TC CROSCOMP # FIRST CALL SUBROUTINE TO COMPUTE THEM
CAF BIT10 # 1/32 TO ITEMP2 FOR USE AS DIVISOR BELOW
TS ITEMP2
CAF MAXVEL # LIMIT COMMAND TO 198.645 F/S
LXCH FORVTEMP
TC LADLIMIT
LXCH FORVTEMP +1
EXTEND # RESCALE TO UNITS OF ONE M/CS
DV ITEMP2
EXTEND # RESCALE TO UNITS OF .5571 F/S/BIT
MP VELCONV
XCH L # ROUND TO NEAREST .5571 F/S
DOUBLE
TS Q
TCF FORVOUT
ADS L
FORVOUT CS FORVMETR # SUBTRACT METER INDICATOR TO GET CHANGE
ADS L
CA MAXDBITS
TC LADLIMIT # LIMIT CHANGE TO ABOUT 300 F/S
AD NEG0
TS CDUSCMD
ADS FORVMETR # UPDATE METER INDICATOR
CAF MAXVEL # LIMIT COMMAND TO 198.645 F/S
LXCH LATVEL
TC LADLIMIT
LXCH LATVEL +1
EXTEND # RESCALE TO UNITS OF ONE M/CS
DV ITEMP2
EXTEND # RESCALE TO UNITS OF .5571 F/S/BIT
MP VELCONV
XCH L # ROUND TO NEAREST .5571 F/S
DOUBLE
TS Q
TCF LATVOUT
ADS L
LATVOUT CS LATVMETR # SUBTRACT METER INDICATOR TO GET CHANGE
ADS L
CAF MAXDBITS
TC LADLIMIT # LIMIT CHANGE TO ABOUT 300 F/S
AD NEG0
TS CDUTCMD
ADS LATVMETR # UPDATE METER INDICATOR
CAF BITSET # SET DRIVE BITS
EXTEND
WOR CHAN14
## Page 894
LANADEND TC TASKOVER
# ************************************************************************
# SUBROUTINE TO COMPUTE FORWARD AND LATERAL VELOCITIES
# ************************************************************************
# THE SCALARS VHY AND VHZ, COMPUTED NEXT, ARE THE VELOCITIES ALONG UNIT VECTORS UHYP AND UHZP. UHYP NORMAL
# TO THE PRE-PDI ORBITAL PLANE, UHZP IN TURN NORMAL TO UHYP AND THE POSITION VECTOR. NOW SINCE FOR THE "LANDING
# ALIGNMENT" OF THE IMU THE STABLE-MEMBER Y-AXIS IS DEFINED THE SAME WAY AS UHYP, VVECTY IS PRECISELY VHY.
# FURTHERMORE, THE Y-TERM OF THE VHZ COMPUTATION DROPS OUT, AND THE FOLLOWING USEFUL EQUALITIES BECOME TRUE:
# UHZPX = - RUNITZ AND UHZPZ = RUNITX. DRAW A PICTURE TO BE CONVINCED.
# NOTE THAT IN THIS VERSION CROSS-POINTER DISPLAYS ARE OUTPUT DURING ASCENT AND ABORTS AS WELL AS DESCENT.
CROSCOMP CS FLAGWRD0 # IS R10FLAG SET TO INDICATE ASCENT?
MASK R10FLBIT
EXTEND
BZF APSLAD # YES: DISPLAY LATVEL IN INERTIAL AXES
CS RUNITZ # NO: COMPUTE DOWNRANGE VELOCITY
EXTEND
MP VVECTX
DXCH VHZ
CA RUNITX
EXTEND
MP VVECTZ
DAS VHZ
CA RUNITX # COMPUTE THE MORE SENSITIVE TERM IN DP
EXTEND
MP VVECTZ +1
TS L
CAF ZERO
DAS VHZ # VHZ IN UNITS OF 2(5) M/CS
EXTEND
DCA VVECTY
DXCH VHY # VHY IN UNITS OF 2(5) M/CS
CAF EBANK6 # SWITCH TO DAP EBANK
TS EBANK
EBANK= M22
CA M32 # COS(AOG)
EXTEND
MP VHZ
DXCH FORVTEMP
CS M22 # SIN(AOG)
EXTEND
MP VHY
DAS FORVTEMP
## Page 895
CA M32 # COS(AOG)
EXTEND
MP VHZ +1
TS ITEMP2
CS M22 # SIN(AOG)
EXTEND
MP VHY +1
AD ITEMP2
TS L
CAF ZERO
DAS FORVTEMP # FORWARD VELOCITY IN UNITS OF 2(5) M/CS
CA M22 # SIN(AOG)
EXTEND
MP VHZ
DXCH LATVEL
CA M32 # COS(AOG)
EXTEND
MP VHY
DAS LATVEL
CA M22 # SIN(AOG)
EXTEND
MP VHZ +1
TS ITEMP2
CA M32 # COS(AOG)
EXTEND
MP VHY +1
AD ITEMP2
TS L
CAF ZERO
DAS LATVEL # LATERAL VELOCITY IN UNITS OF 2(5) M/CS
INCR BBANK # RETURN TO SERVICER EBANK
EBANK= HDOTLAD
CROSSOUT EXTEND # MOVE FORVTEMP TO FORVEL FOR DSKY DISPLAY
DCA FORVTEMP
DXCH FORVEL
TC Q
APSLAD TS FORVTEMP # DURING ASCENT AND ABORTS COME HERE TO
TS FORVTEMP +1 # DISPLAY LATVEL = SM Y-AXIS VELOCITY
EXTEND
DCA VVECTY
DXCH LATVEL
EXTEND # ADD SURFACE VELOCITY BACK IN SO APS
DCA VSURFACE +2 # LATVEL DISPLAY WILL BE IN TRUE
## Page 896
DAS LATVEL # STABLE-MEMBER COORDINATES
TCF CROSSOUT # REJOIN THE MAINSTREAM
# ************************************************************************
# LANDING ANALOG DISPLAYS INITIALIZATION
# ************************************************************************
DISPINIT TC CROSCOMP # FIRST COMPUTE BUT NOT OUTPUT VELOCITIES
CS FLAGWRD1 # SET DIDFLAG
MASK DIDFLBIT
ADS FLAGWRD1
CAF BIT8 # SET DISPLAY INERTIAL DATA OUTBIT
EXTEND
WOR CHAN12
CS ZERO # ZERO METER INDICATORS
TS LATVMETR
TS FORVMETR
CAF BIT4 # SET UP TASK TO FINISH INITIALIZATION
TC TWIDDLE
ADRES INTLZE
TCF LANADEND
INTLZE CAF BIT2 # ENABLE RR ERROR COUNTER
EXTEND
WOR CHAN12
CS IMODES33 # SET INERTIAL DATA FLAG
MASK BIT8
ADS IMODES33
TC TASKOVER
# ************************************************************************
# LANDING ANALOG DISPLAYS RESET ROUTINE
# ************************************************************************
DISPRSET TC CROSCOMP # FIRST COMPUTE BUT NOT OUTPUT VELOCITIES
+1 CS DIDFLBIT # RESET DIDFLAG
MASK FLAGWRD1
TS FLAGWRD1
CAF BIT8 # WAS INERTIAL DATA JUST DISPLAYED?
MASK IMODES33
CCS A
CAF BIT2 # YES: DISABLE RR ERROR COUNTER AND
## Page 897
AD BIT8 # NO: RESET DISPLAY INERTIAL DATA OUTBIT
COM
EXTEND
WAND CHAN12
CS BIT8
MASK IMODES33
TS IMODES33
TCF LANADEND
# ************************************************************************
# CONSTANTS FOR LANDING ANALOG DISPLAYS
# ************************************************************************
# CONSTANTS ON A-CARDS ARE FOUND IN THE CONTROLLED CONSTANTS SECTION
# LANAKPIP DEC .0512 SCALES PIPAS TO UNITS OF 2(5) M/CS
# MAXVEL OCT 00466 198.645 F/S IN UNITS OF 2(5) M/CS
# MAXDBITS OCT 01034 ABOUT 300 F/S
# VELCONV DEC .03594 SCALES VEL AT ONE M/CS TO .5571 F/S/BIT
# ALTRCONV DEC .16020 SCALES ALTR AT 2(2) M/CS TO .5 F/S/BIT
# ALTCONV DEC .69954 SCALES ALTITUDE AT 2(15) M TO 9.38 F/BIT
BITSET = PRIO6 # CROSS-POINTER DRIVE BITS
# ************************************************************************
# SUBROUTINES
# ************************************************************************
LADLIMIT TS ITEMP1
CAF ZERO
EXTEND
DV ITEMP1
CCS A
LXCH ITEMP1
TCF +2
TCF +3
## Page 898
CA L
TC Q
CS ITEMP1
TC Q
NORMPIP XCH ITEMP1
CA ITEMP1
MASK BIT14
EXTEND
BZF +5
CA ITEMP1
AD NEG1/2
AD NEG1/2
TCF +4
+5 CA ITEMP1
AD HALF
AD HALF
+4 ZL
XCH L
XCH L
TC Q
# ************************************************************************
# THE END OF THE LANDING ANALOG DISPLAYS
# ************************************************************************
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