Source Code
|
These source-code files are part of a reconstructed copy of LM131 revision 1,
the final release of the Apollo 13 Lunar Module (LM) Apollo Guidance Computer
(AGC) software.
The source reconstruction began with source code of Luminary 131 previously
transcribed from a digitized copy of that program. A dump of the flight spare
core rope memory module B5, part number 2010802-171, serial number RAY 411,
was obtained. This module is the only module different between Luminary 131
and LM131 revision 1. The dump was disassembled and all changes were incorporated
into these source files. Note that page numbers in the reconstructed code match
those on the Luminary 131 printout, although the changed code would likely have
changed page numbers for a real LM131 revision 1 listing.
Comments from the original source code are prefixed with a single '#' symbol,
whereas comments added later are prefixed by "##" or "###". Report any errors
noted by creating an
issue report at the Virtual AGC
project's GitHub repository.
|
001997,000002: ## Copyright: Public domain.
001998,000003: ## Filename: INPUT_OUTPUT_CHANNEL_BIT_DESCRIPTIONS.agc
001999,000004: ## Purpose: A section of LM131 revision 1.
002000,000005: ## It is part of the reconstructed source code for the final
002001,000006: ## release of the flight software for the Lunar Module's (LM)
002002,000007: ## Apollo Guidance Computer (AGC) for Apollo 13. The code has
002003,000008: ## been reconstructed from a listing of Luminary 131 and a dump
002004,000009: ## of a core rope memory module B5, part number 2010802-171,
002005,000010: ## which is the only module different between LM131 revision 1
002006,000011: ## and Luminary 131. The executable generated from this source
002007,000012: ## has been verified against the module dump, so while the names,
002008,000013: ## comments, and ordering may not be exactly correct, the
002009,000014: ## resulting binary is.
002010,000015: ## Reference: pp. 54-60
002011,000016: ## Assembler: yaYUL
002012,000017: ## Contact: Ron Burkey <info@sandroid.org>.
002013,000018: ## Website: www.ibiblio.org/apollo/index.html
002014,000019: ## Mod history: 2022-10-28 MAS Created from Luminary 131.
002015,000020:
|
|
Page 54
|
002017,000022:
002018,000023: # *** CHANNEL DESCRIPTIONSF WORDS ARE ALLOCATED IN ERASABLE ASSIGNMENTS ***
002019,000024:
002020,000025: # CHANNEL 1 IDENTICAL TO COMPUTER REGISTER L (0001)
002021,000026:
002022,000027: # CHANNEL 2 IDENTICAL TO COMPUTER REGISTER Q (0002)
002023,000028:
002024,000029: # CHANNEL 3 HISCALAR; INPUT CHANNEL; MOST SIGNIFICANT 14 BITS FROM 33 STAGE BINARY COUNTER. SCALE
002025,000030: # FACTOR IS B23 IN CSEC, SO MAX VALUE ABOUT 23.3 HOURS AND LEAST SIGNIFICANT BIT 5.12 SECS.
002026,000031:
002027,000032: # CHANNEL 4 LOSCALAR; INPUT CHANNEL; NEXT MOST SIGNIFICANT 14 BITS FROM THE 33 STAGE BINARY COUNTER
002028,000033: # ASSOCIATED WITH CHANNEL 3. SCALE FACTOR IS B9 IN CSEC. SO MAX VAL IS 5.12 SEC AND LEAST
002029,000034: # SIGNIFICANT BIT IS 1/3200 SEC. SCALE FACTOR OF D.P. WORD WITH CHANNEL 3 IS B23 CSEC.
002030,000035:
002031,000036: # CHANNEL 5 PYJETS; OUTPUT CHANNEL; PITCH RCS JET CONTROL. (REACTION CONTROL SYSTEM) USES BITS 1-8.
002032,000037:
002033,000038: # CHANNEL 6 ROLLJETS; OUTPUT CHANNEL; ROLL RCS JET CONTROL. (REACTION CONTROL SYSTEM) USES BIT 1-8.
002034,000039:
002035,000040: # CHANNEL 7 SUPERBNK; OUTPUT CHANNEL; NOT RESET BY RESTART; FIXED EXTENSION BITS USED TO SELECT THE
002036,000041: # APPROPRIATE FIXED MEMORY BANK IF FBANK IS 30 OCTAL OR MORE. USES BITS 5-7.
002037,000042:
002038,000043: # CHANNEL 10 OUTO; OUTPUT CHANNEL; REGISTER USED TO TRANSMIT LATCHING-RELAY DRIVING INFORMATION FOR
002039,000044: # THE DISPLAY SYSTEM. BITS 15-12 ARE SET TO THE ROW NUMBER (1-14 OCTAL) OF THE RELAY TO BE
002040,000045: # CHANGED AND BITS 11-1 CONTAIN THE REQUIRED SETTINGS FOR THE RELAYS IN THE ROW.
002041,000046:
002042,000047: # CHANNEL 11 DSALMOUT; OUTPUT CHANNEL; REGISTER WHOSE BITS ARE USED FOR ENGINE ON-OFF CONTROL AND TO
002043,000048: # DRIVE INDIVIDUAL INDICATORS OF THE DISPLAY SYSTEM. BITS 1-7 ARE A RELAYS.
002044,000049:
002045,000050: # BIT 1 ISS WARNING
002046,000051: # BIT 2 LIGHT COMPUTER ACTIVITY LAMP
002047,000052: # BIT 3 LIGHT UPLINK ACTIVITY LAMP
002048,000053: # BIT 4 LIGHT TEMP CAUTION LAMP
002049,000054: # BIT 5 LIGHT KEYBOARD RELEASE LAMP
002050,000055: # BIT 6 FLASH VERB AND NOUN LAMPS
002051,000056: # BIT 7 LIGHT OPERATOR ERROR LAMP
|
|
Page 55
|
002053,000058: # BIT 8 SPARE
002054,000059: # BIT 9 TEST CONNECTOR OUTBIT
002055,000060: # BIT 10 CAUTION RESET
002056,000061: # BIT 11 SPARE
002057,000062: # BIT 12 SPARE
002058,000063: # BIT 13 ENGINE ON
002059,000064: # BIT 14 ENGINE OFF
002060,000065: # BIT 15 SPARE
002061,000066:
002062,000067: # CHANNEL 12 CHAN12; OUTPUT CHANNEL; BITS USED TO DRIVE NAVIGATION AND SPAECRAFT HARDWARE
002063,000068:
002064,000069: # BIT 1 ZERO RR CDU; CDU'S GIVE RRADAR INFORMATION FOR LM
002065,000070: # BIT 2 ENABLE CDU RADAR ERROR COUNTERS
002066,000071: # BIT 3 NOT USED
002067,000072: # BIT 4 COARSE ALIGN ENABLE OF IMU
002068,000073: # BIT 5 ZERO IMU CDU'S
002069,000074: # BIT 6 ENABLE IMU ERROR COUNTER, CDU ERROR COUNTER.
002070,000075: # BIT 7 SPARE
002071,000076: # BIT 8 DISPLAY INERTIAL DATA
002072,000077: # BIT 9 -PITCH GIMBAL TRIM (BELL MOTION) DESCENT ENGINE
002073,000078: # BIT 10 +PITCH GIMBAL TRIM (BELL MOTION) DESCENT ENGINE
002074,000079: # BIT 11 -ROLL GIMBAL TRIM (BELL MOTION) DESCENT ENGINE
002075,000080: # BIT 12 +ROLL GIMBAL TRIM (BELL MOTION) DESCENT ENGINE
002076,000081: # BIT 13 LR POSITION 2 COMMAND
002077,000082: # BIT 14 ENABLE RENDESVOUS RADAR LOCK-ON; AUTO ANGLE TRACK'G
002078,000083: # BIT 15 ISS TURN ON DELAY COMPLETE
002079,000084:
|
|
Page 56
|
002081,000086: # CHANNEL 13 CHAN13; OUTPUT CHANNEL
002082,000087:
002083,000088: # BIT 1 RADAR C PROPER SETTING OF THE A,B,C MATRIX
002084,000089: # BIT 2 RADAR B SELECTS CERTAIN RADAR
002085,000090: # BIT 3 RADAR A PARAMETERS TO BE READ.
002086,000091: # BIT 4 RADAR ACTIVITY
002087,000092: # BIT 5 NOT USED (CONNECTS AN ALTERNATE INPUT TO UPLINK)
002088,000093: # BIT 6 SPARE
002089,000094: # BIT 7 DOWNLINK TELEMETRY WORD ORDER CODE BIT
002090,000095: # BIT 8 RHC COUNTER ENABLE (READ HAND CONTROLLER ANGLES)
002091,000096: # BIT 9 START RHC READ INTO COUNTERS IF BIT 8 SET
002092,000097: # BIT 10 TEST ALARMS, TEST DSKY LIGHTS
002093,000098: # BIT 11 ENABLE STANDBY
002094,000099: # BIT 12 RESET TRAP 31-A ALWAYS APPEAR TO BE SET TO 0
002095,000100: # BIT 13 RESET TRAP 31-B ALWAYS APPEAR TO BE SET TO 0
002096,000101: # BIT 14 RESET TRAP 32 ALWAYS APPEAR TO BE SET TO 0
002097,000102: # BIT 15 ENABLE T6 RUPT
002098,000103:
002099,000104: # CHANNEL 14 CHAN14; OUTPUT CHANNEL; USED TO CONTROL COMPUTER COUNTER CELLS (CDU, GYRO, SPACECRAFT FUNC.
002100,000105:
002101,000106: # BIT 1 OUTLINK ACTIVITY (NOT USED)
002102,000107: # BIT 2 ALTITUDE RATE OR ALTITIDE SELECTOR
002103,000108: # BIT 3 ALTITUDE METER ACTIVITY
002104,000109: # BIT 4 THRUST DRIVE ACTIVITY FOR DESCENT ENGINE
002105,000110: # BIT 5 SPARE
002106,000111: # BIT 6 GYRO ENABLE POWER FOR PULSES
002107,000112: # BIT 7 GYRO SELECT B PAIR OF BITS IDENTIFIES AXIS OF -
002108,000113: # BIT 8 GYRO SELECT A GYRO SYSTEM TO BE TORQUED.
002109,000114: # BIT 9 GYRO TORQUING COMMAND IN NEGATIVE DIRECTION
|
|
Page 57
|
002111,000116: # BIT 10 GYRO ACTIVITY
002112,000117: # BIT 11 DRIVE CDU S
002113,000118: # BIT 12 DRIVE CDU T
002114,000119: # BIT 13 DRIVE CDU Z
002115,000120: # BIT 14 DRIVE CDU Y
002116,000121: # BIT 15 DRIVE CDU X
002117,000122:
002118,000123: # CHANNEL 15 MNKEYIN; INPUT CHANNEL; KEY CODE INPUT FROM KEYBOARD OF DSKY, SENSED BY PROGRAM WHEN
002119,000124: # PROGRAM INTERRUPT #5 IS RECEIVED. USES BITS 5-1
002120,000125:
002121,000126: # CHANNEL 16 NAVKEYIN; INPUT CHANNEL; OPTICS MARK INFORMATION AND NAVIGA ION PANEL DSKY (CM) OR THRUST
002122,000127: # CONTROL (LM) SENSED BY PROGRAM WHEN PROGRAM INTER-RUPT #6 IS RECEIVED. USES BITS 3-7 ONLY.
002123,000128:
002124,000129: # BIT 1 NOT ASSIGNED
002125,000130: # BIT 2 NOT ASSIGNED
002126,000131: # BIT 3 OPTICS X-AXIS MARK SIGNAL FOR ALIGN OPTICAL TSCOPE
002127,000132: # BIT 4 OPTICS Y-AXIS MARK SIGNAL FOR AOT
002128,000133: # BIT 5 OPTICS MARK REJECT SIGNAL
002129,000134: # BIT 6 DESCENT+ ; CREW DESIRED SLOWING RATE OF DESCENT
002130,000135: # BIT 7 DESCENT- ; CREW DESIRED SPEEDING UP RATE OF D'CENT
002131,000136:
002132,000137: # NOTE: ALL BITS IN CHANNELS 30-33 ARE INVERTED AS SENSED BY THE PROGRAM, SO THAT A VALUE OF ZERO MEANS
002133,000138: # THAT THE INDICATED SIGNAL IS PRESENT.
002134,000139:
002135,000140: # CHANNEL 30 INPUT CHANNEL
002136,000141:
002137,000142: # BIT 1 ABORT WITH DESCENT STAGE
002138,000143: # BIT 2 UNUSED
002139,000144: # BIT 3 ENGINE ARMED SIGNAL
002140,000145: # BIT 4 ABORT WITH ASCENT ENGINE STAGE
002141,000146: # BIT 5 AUTO THROTTLE; COMPUTER CONTROL OF DESCENT ENGINE
|
|
Page 58
|
002143,000148: # BIT 6 DISPLAY INERTIAL DATA
002144,000149: # BIT 7 RR CDU FAIL
002145,000150: # BIT 8 SPARE
002146,000151: # BIT 9 IMU OPERATE WITH NO MALFUNCTION
002147,000152: # BIT 10 LM COMPUTER (NOT AGS) HAS CONTROL OF LM
002148,000153: # BIT 11 IMU CAGE COMMAND TO DRIVE IMU GIMBAL ANGLES TO 0.
002149,000154: # BIT 12 IMU CDU FAIL (MALFUNCTION OF IMU CDU,S)
002150,000155: # BIT 13 IMU FAIL (MALFUNCTION OF IMU STABILIZATION LOOPS)
002151,000156: # BIT 14 ISS TURN ON REQUESTED
002152,000157: # BIT 15 TEMPERATURE OF STABLE MEMBER WITHIN DESIGN LIMITS
002153,000158:
002154,000159: # CHANNEL 31 INPUT CHANNEL; BITS ASSOCIATED WITH THE ATTITUDE CONTROLLER, TRANSLATIONAL CONTROLLER,
002155,000160: # AND SPACECRAFT ATTITUDE CONTROL; USED BY RCS DAP
002156,000161:
002157,000162: # BIT 1 ROTATION (BY RHC) COMMANDED IN POSITIVE PITCH DIRECTION; MUST BE IN MINIMUM IMPULSE MODE.
002158,000163: # ALSO POSITIVE ELEVATION CHANGE FOR LANDING POINT DESIGNATOR
002159,000164: # BIT 2 AS BIT 1 EXCEPT NEGATIVE PITCH AND ELEVATION
002160,000165: # BIT 3 ROTATION (BY RHC) COMMANDED IN POSITIVE YAW DIRECTION; MUST BE IN MINUMUM IMPULSE MODE.
002161,000166: # BIT 4 AS BIT 3 EXCEPT NEGATIVE YAW
002162,000167: # BIT 5 ROTATION (BY RHC) COMMANDED IN POSITIVE ROLL DIRECTION; MUST BE IN MINIMUM IMPULSE MODE.
002163,000168: # ALSO POSITIVE AZIMUTH CHANGE FOR LANDING POINT DESIGNATOR
002164,000169: # BIT 6 AS BIT 5 EXCEPT NEGATIVE ROLL AND AZIMUTH
002165,000170: # BIT 7 TRANSLATION IN +X DIRECTION COMMANDED BY THC
002166,000171: # BIT 8 TRANSLATION IN -X DIRECTION COMMANDED BY THC
002167,000172: # BIT 9 TRANSLATION IN +Y DIRECTION COMMANDED BY THC
002168,000173: # BIT 10 TRANSLATION IN -Y DIRECTION COMMANDED BY THC
002169,000174: # BIT 11 TRANSLATION IN +Z DIRECTION COMMANDED BY THC
002170,000175: # BIT 12 TRANSLATION IN -Z DIRECTION COMMANDED BY THC
|
|
Page 59
|
002172,000177: # BIT 13 ATTITUDE HOLD MODE ON SCS MODE CONTROL SWITCH
002173,000178: # BIT 14 AUTO STABILIZATION OF ATTITUDE ON SCS MODE SWITCH
002174,000179: # BIT 15 ATTITUDE CONTROL OUT OF DETENT (RHC NOT IN NEUTRAL
002175,000180:
002176,000181: # CHANNEL 32 INPUT CHANNEL.
002177,000182:
002178,000183: # BIT 1 THRUSTERS 2 & 4 DISABLED BY CREW
002179,000184: # BIT 2 THRUSTERS 5 & 8 DISABLED BY CREW
002180,000185: # BIT 3 THRUSTERS 1 & 3 DISABLED BY CREW
002181,000186: # BIT 4 THRUSTERS 6 & 7 DISABLED BY CREW
002182,000187: # BIT 5 THRUSTERS 14 & 16 DISABLED BY CREW
002183,000188: # BIT 6 THRUSTERS 13 & 15 DISABLED BY CREW
002184,000189: # BIT 7 THRUSTERS 9 & 12 DISABLED BY CREW
002185,000190: # BIT 8 THRUSTERS 10 & 11 DISABLED BY CREW
002186,000191: # BIT 9 DESCENT ENGINE GIMBALS DISABLED BY CREW
002187,000192: # BIT 10 APPARENT DESCENT ENGINE GIMBAL FAILURE
002188,000193: # BIT 14 INDICATES PROCEED KEY IS DEPRESSED
002189,000194:
002190,000195: # CHANNEL 33 CHAN33; INPUT CHANNEL; FOR HARDWARE STATUS AND COMMAND INFORMATION. BITS 15-11 ARE FLIP-
002191,000196: # FLOP BITS RESET BY A CHANNEL "WRITE" COMMAND THAT ARE RESET BY A RESTART & BY T4RUPT LOOP.
002192,000197:
002193,000198: # BIT 1 SPARE
002194,000199: # BIT 2 RR AUTO-POWER ON
002195,000200: # BIT 3 RR RANGE LOW SCALE
002196,000201: # BIT 4 RR DATA GOOD
002197,000202: # BIT 5 LR RANGE DATA GOOD
002198,000203: # BIT 6 LR POS1
002199,000204: # BIT 7 LR POS2
|
|
Page 60
|
002201,000206: # BIT 8 LR VEL DATA GOOD
002202,000207: # BIT 9 LR RANGE LOW SCALE
002203,000208: # BIT 10 BLOCK UPLINK INPUT
002204,000209: # BIT 11 UPLINK TOO FAST
002205,000210: # BIT 12 DOWNLINK TOO FAST
002206,000211: # BIT 13 PIPA FAIL
002207,000212: # BIT 14 WARNING OF REPEATED ALARMS: RESTART, COUNTER FAIL, VOLTAGE FAIL, AND SCALAR DOUBLE.
002208,000213: # BIT 15 LGC OSCILLATOR STOPPED
002209,000214:
002210,000215: # CHANNEL 34 DNT M1; OUTPUT CHANNEL; DOWNLINK 1 FIRST OF TWO WORDS SERIALIZATION.
002211,000216:
002212,000217: # CHANNEL 35 DNT M2; OUTPUT CHANNEL DOWNLINK 2 SOCOND OF TWO WORDS SERIALIZATION.
002213,000218:
002214,000219:
End of include-file INPUT_OUTPUT_CHANNEL_BIT_DESCRIPTIONS.agc. Parent file is MAIN.agc