INPUT OUTPUT CHANNEL BIT DESCRIPTIONS

Scanned pages: 0054-0060
# Copyright:  Public domain.
# Filename:  INPUT_OUTPUT_CHANNEL_BIT_DESCRIPTIONS.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:  0054-0060
# Mod history:  2009-05-14 OH  Transcribed from page images.
#
# 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 54

# ***  CHANNEL DESCRIPTIONSF WORDS ARE ALLOCATED IN ERASABLE ASSIGNMENTS ***

#  CHANNEL 1  IDENTICAL TO COMPUTER REGISTER L (0001)

#  CHANNEL 2  IDENTICAL TO COMPUTER REGISTER Q (0002)

#  CHANNEL 3  HISCALAR; INPUT CHANNEL; MOST SIGNIFICANT 14 BITS FROM 33 STAGE BINARY COUNTER. SCALE
#      FACTOR IS B23 IN CSEC, SO MAX VALUE ABOUT 23.3 HOURS AND LEAST SIGNIFICANT BIT 5.12 SECS.

#  CHANNEL 4  LOSCALAR; INPUT CHANNEL; NEXT MOST SIGNIFICANT 14 BITS FROM THE 33 STAGE BINARY COUNTER
#      ASSOCIATED WITH CHANNEL 3. SCALE FACTOR IS B9 IN  CSEC. SO MAX VAL IS 5.12 SEC AND LEAST
#      SIGNIFICANT BIT IS 1/3200 SEC. SCALE FACTOR OF D.P. WORD WITH CHANNEL 3 IS B23 CSEC.

#  CHANNEL 5  PYJETS; OUTPUT CHANNEL; PITCH RCS JET CONTROL.   (REACTION CONTROL SYSTEM) USES BITS 1-8.

#  CHANNEL 6  ROLLJETS; OUTPUT CHANNEL; ROLL RCS JET CONTROL.   (REACTION CONTROL SYSTEM) USES BIT 1-8.

#  CHANNEL 7  SUPERBNK; OUTPUT CHANNEL; NOT RESET BY RESTART;   FIXED EXTENSION BITS USED TO SELECT THE
#      APPROPRIATE FIXED MEMORY BANK IF FBANK IS 30 OCTAL OR MORE. USES BITS 5-7.

#  CHANNEL 10  OUT0; OUTPUT CHANNEL; REGISTER USED TO TRANSMIT    LATCHING-RELAY DRIVING INFORMATION FOR
#      THE DISPLAY SYSTEM.  BITS 15-12 ARE SET TO THE ROW NUMBER (1-14 OCTAL) OF THE RELAY TO BE
#      CHANGED AND BITS 11-1 CONTAIN THE REQUIRED SETTINGS FOR THE RELAYS IN THE ROW.

#  CHANNEL 11  DSALMOUT; OUTPUT CHANNEL; REGISTER WHOSE BITS ARE USED FOR ENGINE ON-OFF CONTROL AND TO
#      DRIVE INDIVIDUAL INDICATORS OF THE DISPLAY SYSTEM. BITS 1-7 ARE A RELAYS.
#
#    BIT 1    ISS WARNING
#    BIT 2    LIGHT COMPUTER ACTIVITY LAMP
#    BIT 3    LIGHT UPLINK ACTIVITY LAMP
#    BIT 4    LIGHT TEMP CAUTION LAMP
#    BIT 5    LIGHT KEYBOARD RELEASE LAMP
#    BIT 6    FLASH VERB AND NOUN LAMPS
#    BIT 7    LIGHT OPERATOR ERROR LAMP
# Page 55
#    BIT 8    SPARE
#    BIT 9    TEST CONNECTOR OUTBIT
#    BIT 10  CAUTION RESET
#    BIT 11  SPARE
#    BIT 12  SPARE
#    BIT 13  ENGINE ON
#    BIT 14  ENGINE OFF
#    BIT 15  SPARE

#  CHANNEL 12  CHAN12; OUTPUT CHANNEL; BITS USED TO DRIVE NAVIGATION AND SPAECRAFT HARDWARE
#
#    BIT 1    ZERO RR CDU; CDU'S GIVE RRADAR INFORMATION FOR LM
#    BIT 2    ENABLE CDU RADAR ERROR COUNTERS
#    BIT 3    NOT USED
#    BIT 4    COARSE ALIGN ENABLE OF IMU
#    BIT 5    ZERO IMU CDU'S
#    BIT 6    ENABLE IMU ERROR COUNTER, CDU ERROR COUNTER.
#    BIT 7    SPARE
#    BIT 8    DISPLAY INERTIAL DATA
#    BIT 9    -PITCH GIMBAL TRIM (BELL MOTION) DESCENT ENGINE
#    BIT 10  +PITCH GIMBAL TRIM (BELL MOTION) DESCENT ENGINE
#    BIT 11  -ROLL  GIMBAL TRIM (BELL MOTION) DESCENT ENGINE
#    BIT 12  +ROLL  GIMBAL TRIM (BELL MOTION) DESCENT ENGINE
#    BIT 13  LR POSITION 2 COMMAND
#    BIT 14  ENABLE RENDESVOUS RADAR LOCK-ON;AUTO ANGLE TRACK'G
#    BIT 15  ISS TURN ON DELAY COMPLETE

# Page 56
#  CHANNEL 13  CHAN13; OUTPUT CHANNEL.
#
#    BIT 1    RADAR C    PROPER SETTING OF THE A,B,C MATRIX
#    BIT 2    RADAR B    SELECTS CERTAIN RADAR
#    BIT 3    RADAR A    PARAMETERS TO BE READ.
#    BIT 4    RADAR ACTIVITY
#    BIT 5    NOT USED (CONNECTS AN ALTERNATE INPUT TO UPLINK)
#    BIT 6    BLOCK INPUTS TO UPLINK CELL
#    BIT 7    DOWNLINK TELEMETRY WORD ORDER CODE BIT
#    BIT 8    RHC COUNTER ENABLE (READ HAND CONTROLLER ANGLES)
#    BIT 9    START RHC READ INTO COUNTERS IF BIT 8 SET
#    BIT 10  TEST ALARMS, TEST DSKY LIGHTS
#    BIT 11  ENABLE STANDBY
#    BIT 12  RESET TRAP 31-A    ALWAYS APPEAR TO BE SET TO 0
#    BIT 13  RESET TRAP 31-B    ALWAYS APPEAR TO BE SET TO 0
#    BIT 14  RESET TRAP 32    ALWAYS APPEAR TO BE SET TO 0
#    BIT 15  ENABLE T6 RUPT

#  CHANNEL 14  CHAN14; OUTPUT CHANNEL; USED TO CONTROL COMPUTER  COUNTER CELLS (CDU,GYRO,SPACECRAFT FUNC.
#
#    BIT 1    OUTLINK ACTIVITY (NOT USED)
#    BIT 2    ALTITUDE RATE OR ALTITIDE SELECTOR
#    BIT 3    ALTITUDE METER ACTIVITY
#    BIT 4    THRUST DRIVE ACTIVITY FOR DESCENT ENGINE
#    BIT 5    SPARE
#    BIT 6    GYRO ENABLE POWER FOR PULSES
#    BIT 7    GYRO SELECT B    PAIR OF BITS IDENTIFIES AXIS OF -
#    BIT 8    GYRO SELECT A    GYRO SYSTEM TO BE TORQUED.
#    BIT 9    GYRO TORQUING COMMAND IN NEGATIVE DIRECTION
# Page 57
#    BIT 10  GYRO ACTIVITY
#    BIT 11  DRIVE CDU S
#    BIT 12  DRIVE CDU T
#    BIT 13  DRIVE CDU Z
#    BIT 14  DRIVE CDU Y
#    BIT 15  DRIVE CDU X

#  CHANNEL 15  MNKEYIN; INPUT CHANNEL;KEY CODE INPUT FROM KEYBOARD OF DSKY, SENSED BY PROGRAM WHEN
#      PROGRAM INTERRUPT #5 IS RECEIVED. USES BITS 5-1

#  CHANNEL 16  NAVKEYIN; INPUT CHANNEL; OPTICS MARK INFORMATION AND NAVIGA ION PANEL DSKY (CM) OR THRUST
#      CONTROL (LM) SENSED BY PROGRAM WHEN PROGRAM INTER-RUPT #6 IS RECEIVED. USES BITS 3-7 ONLY.
#
#    BIT 1    NOT ASSIGNED
#    BIT 2    NOT ASSIGNED
#    BIT 3    OPTICS X-AXIS MARK SIGNAL FOR ALIGN OPTICAL TSCOPE
#    BIT 4    OPTICS Y-AXIS MARK SIGNAL FOR AOT
#    BIT 5    OPTICS MARK REJECT SIGNAL
#    BIT 6    DESCENT+ ; CREW DESIRED SLOWING RATE OF DESCENT
#    BIT 7    DESCENT- ; CREW DESIRED SPEEDING UP RATE OF D'CENT

# NOTE: ALL BITS IN CHANNELS 30-33 ARE INVERTED AS SENSED BY THE  PROGRAM, SO THAT A VALUE OF ZERO MEANS
# THAT THE INDICATED SIGNAL IS PRESENT.

#  CHANNEL 30  INPUT CHANNEL
#
#    BIT 1    ABORT WITH DESCENT STAGE
#    BIT 2       UNUSED
#    BIT 3    ENGINE ARMED SIGNAL
#    BIT 4    ABORT WITH ASCENT ENGINE STAGE
#    BIT 5    AUTO THROTTLE; COMPUTER CONTROL OF DESCENT ENGINE
# Page 58
#    BIT 6    DISPLAY INERTIAL DATA
#    BIT 7    RR CDU FAIL
#    BIT 8    SPARE
#    BIT 9    IMU OPERATE WITH NO MALFUNCTION
#    BIT 10  LM COMPUTER (NOT AGS) HAS CONTROL OF LM
#    BIT 11  IMU CAGE COMMAND TO DRIVE IMU GIMBAL ANGLES TO 0.
#    BIT 12  IMU CDU FAIL (MALFUNCTION OF IMU CDU,S)
#    BIT 13  IMU FAIL (MALFUNCTION OF IMU STABILIZATION LOOPS)
#    BIT 14  ISS TURN ON REQUESTED
#    BIT 15  TEMPERATURE OF STABLE MEMBER WITHIN DESIGN LIMITS

#  CHANNEL 31  INPUT CHANNEL; BITS ASSOCIATED WITH THE ATTITUDE  CONTROLLER, TRANSLATIONAL CONTROLLER,
#      AND SPACECRAFT ATTITUDE CONTROL; USED BY RCS DAP
#
#    BIT 1    ROTATION (BY RHC) COMMANDED IN POSITIVE PITCH DIRECTION; MUST BE IN MINIMUM IMPULSE MODE.
#      ALSO POSITIVE ELEVATION CHANGE FOR LANDING POINT  DESIGNATOR
#    BIT 2    AS BIT 1 EXCEPT NEGATIVE PITCH AND ELEVATION
#    BIT 3    ROTATION (BY RHC) COMMANDED IN POSITIVE YAW DIRECTION; MUST BE IN MINIMUM IMPULSE MODE.
#    BIT 4    AS BIT 3 EXCEPT NEGATIVE YAW
#    BIT 5    ROTATION (BY RHC) COMMANDED IN POSITIVE ROLL DIRECTION; MUST BE IN MINIMUM IMPULSE MODE.
#      ALSO POSITIVE AZIMUTH CHANGE FOR LANDING POINT DESIGNATOR
#    BIT 6    AS BIT 5 EXCEPT NEGATIVE ROLL AND AZIMUTH
#    BIT 7    TRANSLATION IN +X DIRECTION COMMANDED BY THC
#    BIT 8    TRANSLATION IN -X DIRECTION COMMANDED BY THC
#    BIT 9    TRANSLATION IN +Y DIRECTION COMMANDED BY THC
#    BIT 10  TRANSLATION IN -Y DIRECTION COMMANDED BY THC
#    BIT 11  TRANSLATION IN +Z DIRECTION COMMANDED BY THC
#    BIT 12  TRANSLATION IN -Z DIRECTION COMMANDED BY THC
# Page 59
#    BIT 13  ATTITUDE HOLD MODE ON SCS MODE CONTROL SWITCH
#    BIT 14  AUTO STABILIZATION OF ATTITUDE ON SCS MODE SWITCH
#    BIT 15  ATTITUDE CONTROL OUT OF DETENT (RHC NOT IN NEUTRAL

#  CHANNEL 32     INPUT CHANNEL.
#
#    BIT 1       THRUSTERS 2 & 4 DISABLED BY CREW
#    BIT 2       THRUSTERS 5 & 8 DISABLED BY CREW
#    BIT 3       THRUSTERS 1 & 3 DISABLED BY CREW
#    BIT 4       THRUSTERS 6 & 7 DISABLED BY CREW
#    BIT 5       THRUSTERS 14 & 16 DISABLED BY CREW
#    BIT 6       THRUSTERS 13 & 15 DISABLED BY CREW
#    BIT 7       THRUSTERS 9 & 12 DISABLED BY CREW
#    BIT 8       THRUSTERS 10 & 11 DISABLED BY CREW
#    BIT 9       DESCENT ENGINE GIMBALS DISABLED BY CREW
#    BIT 10     APPARENT DESCENT ENGINE GIMBAL FAILURE
#    BIT 14  INDICATES PROCEED KEY IS DEPRESSED

#  CHANNEL 33  CHAN33; INPUT CHANNEL; FOR HARDWARE STATUS AND COMMAND INFORMATION. BITS 15-11 ARE FLIP-
#      FLOP BITS RESET BY A CHANNEL "WRITE" COMMAND THAT ARE RESET BY A RESTART & BY T4RUPT LOOP.
#
#    BIT 1    SPARE
#    BIT 2    RR AUTO-POWER ON
#    BIT 3    RR RANGE LOW SCALE
#    BIT 4    RR DATA GOOD
#    BIT 5    LR RANGE DATA GOOD
#    BIT 6    LR POS1
#    BIT 7    LR POS2
# Page 60
#    BIT 8    LR VEL DATA GOOD
#    BIT 9    LR RANGE LOW SCALE
#    BIT 10  BLOCK UPLINK INPUT
#    BIT 11  UPLINK TOO FAST
#    BIT 12  DOWNLINK TOO FAST
#    BIT 13  PIPA FAIL
#    BIT 14  WARNING OF REPEATED ALARMS: RESTART,COUNTER FAIL, VOLTAGE FAIL,AND SCALAR DOUBLE.
#    BIT 15  LGC OSCILLATOR STOPPED

#  CHANNEL 34  DNT M1; OUTPUT CHANNEL; DOWNLINK 1  FIRST OF TWO WORDS SERIALIZATION.
#  CHANNEL 35  DNT M2; OUTPUT CHANNEL DOWNLINK 2 SOCOND OF TWO   WORDS SERIALIZATION.