Notations on the program listing read, in part:
GAP: ASSEMBLE REVISION 116 OF AGC PROGRAM LUMINARY BY NASA 2021112-071 19:09 AUG. 11,1969Note that the date is the date of the printout, not the date of the program revision.
Source Code
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These source-code files derive from a printout of Luminary 116 (the Apollo 12
Lunar Module guidance computer program), from the personal library of
original AGC developer Don Eyles, digitally photographed at archive.org,
financially sponsored by Ron Burkey, and transcribed to source code by a
team of volunteers. This colorized, syntax-highlighted form was created
by assembling that transcribed source code. Note that the full page images
are available on the
Virtual AGC project page at archive.org, while reduced-size images
are presented at the VirtualAGC project website. Report or fix any
transcription errors at
the Virtual AGC project code repository. Notations on the program listing read, in part: GAP: ASSEMBLE REVISION 116 OF AGC PROGRAM LUMINARY BY NASA 2021112-071 19:09 AUG. 11,1969Note that the date is the date of the printout, not the date of the program revision. |
007857,000002: ## Copyright: Public domain.
007858,000003: ## Filename: RCS_FAILURE_MONITOR.agc
007859,000004: ## Purpose: A section of Luminary revision 116.
007860,000005: ## It is part of the source code for the Lunar Module's (LM)
007861,000006: ## Apollo Guidance Computer (AGC) for Apollo 12.
007862,000007: ## This file is intended to be a faithful transcription, except
007863,000008: ## that the code format has been changed to conform to the
007864,000009: ## requirements of the yaYUL assembler rather than the
007865,000010: ## original YUL assembler.
007866,000011: ## Reference: pp. 191-193
007867,000012: ## Assembler: yaYUL
007868,000013: ## Contact: Ron Burkey <info@sandroid.org>.
007869,000014: ## Website: www.ibiblio.org/apollo/index.html
007870,000015: ## Mod history: 2017-01-22 MAS Created from Luminary 99.
007871,000016: ## 2017-03-12 HG Transcribed
007872,000017: ## 2017-03-14 RSB Proofed comment text via 3-way diff vs
007873,000018: ## Luminary 99 and 131.
007874,000019: ## 2017-08-18 RSB Comment-text bug identified in ZERLINA 56.
007875,000020:
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Page 191 |
007877,000022: # PROGRAM DESCRIPTION
007878,000023:
007879,000024: # AUTHOR: J S MILLER
007880,000025:
007881,000026: # MODIFIED 6 MARCH 1968 BY P S WEISSMAN TO SET UP JOB FOR 1/ACCS WHEN THE MASKS ARE CHANGED.
007882,000027:
007883,000028: # THIS ROUTINE IS ATTACHED TO T4RUPT, AND IS ENTERED EVERY 480 MS. ITS FUNCTION IS TO EXAMINE THE LOW 8 BITS
007884,000029: # OF CHANNEL 32 TO SEE IF ANY ISOLATION-VALVE CLOSURE BITS HAVE APPEARED OR DISAPPEARED (THE CREW IS WARNED OF JET
007885,000030: # FAILURES BY LAMPS LIT BY THE GRUMMAN FAILURE-DETECTION CIRCUITRY; THEY MAY RESPOND BY OPERATING SWITCHES WHICH
007886,000031: # ISOLATE PAIRS OF JETS FROM THE PROPELLANT TANKS AND SET BITS IN CHANNEL 32). IN THE EVENT THAT CHANNEL 32 BITS
007887,000032: # DIFFER FROM 'PVALVEST', THE RECORD OF ACTIONS TAKEN BY THIS ROUTINE, THE APPROPRIATE BITS IN 'CH5MASK' &
007888,000033: # 'CH6MASK', USED BY THE DAP JET-SELECTION LOGIC, ARE UPDATED, AS IS 'PVALVEST'. TO SPEED UP & SHORTEN THE
007889,000034: # ROUTINE, NO MORE THAN ONE CHANGE IS ACCEPTED PER ENTRY. THE HIGHEST-NUMBERED BIT IN CHANNEL 32 WHICH REQUIRES
007890,000035: # ACTION IS THE ONE PROCESSED.
007891,000036:
007892,000037: # THE CODING IN THE FAILURE MONITOR HAS BEEN WRITTEN SO AS TO HAVE ALMOST COMPLETE RESTART PROTECTION. FOR
007893,000038: # EXAMPLE, NO ASSUMPTION IS MADE WHEN SETTING A 'CH5MASK' BIT TO 1 THAT THE PREVIOUS STATE IS 0, ALTHOUGH IT OF
007894,000039: # COURSE SHOULD BE. ONE CASE WHICH MAY BE SEEN TO EVADE PROTECTION IS THE OCCURRENCE OF A RESTART AFTER UPDATING
007895,000040: # ONE OR BOTH DAP MASK-WORDS BUT BEFORE UPDATING 'PVALVEST', COUPLED WITH A CHANGE IN THE VALVE-BIT BACK TO ITS
007896,000041: # FORMER STATE. THE CONSEQUENCE OF THIS IS THAT THE NEXT ENTRY WOULD NOT SEE THE CHANGE INCOMPLETELY INCORP-
007897,000042: # ORATED BY THE LAST PASS (BECAUSE IT WENT AWAY AT JUST THE RIGHT TIME), BUT THE DAP MASK-WORDS WILL BE INCORRECT.
007898,000043: # THIS COMBINATION OF EVENTS SEEMS QUITE REMOTE, BUT NOT IMPOSSIBLE UNLESS THE CREW OPERATES THE SWITCHES AT HALF-
007899,000044: # SECOND INTERVALS OR LONGER. IN ANY EVENT, A DISAGREEMENT BETWEEN REALITY AND THE DAP MASKS WILL BE CURED IF
007900,000045: # THE MISINTERPRETED SWITCH IS REVERSED AND THEN RESTORED TO ITS CORRECT POSITION (SLOWLY).
007901,000046:
007902,000047: # CALLING SEQUENCE:
007903,000048:
007904,000049: # TCF RCSMONIT (IN INTERRUPT MODE, EVERY 480 MS.)
007905,000050:
007906,000051: # EXIT: TCF RCSMONEX (ALL PATHS EXIT VIA SUCH AN INSTRUCTION)
007907,000052: 06,3164 5270 RCSMONEX EQUALS RESUME
007908,000053:
007909,000054: # ERASABLE INITIALIZATION REQUIRED:
007910,000055:
007911,000056: # VIA FRESH START: PVALVEST = +0 (ALL JETS ENABLED)
007912,000057: # CH5MASK, CH6MASK = +0 (ALL JETS OK)
007913,000058:
007914,000059: # OUTPUT: CH5MASK & CH6MASK UPDATED (1'S WHERE JETS NOT TO BE USED, IN CHANNEL 5 & 6 FORMAT)
007915,000060: # PVALTEST UPDATED (1,S WHEN VALVE CLOSURES HAVE BEEN TRANSLATED INTO CH5MASK & CH6MASK; CHAN 32 FORMAT)
007916,000061: # JOB TO DO 1/ACCS.
007917,000062:
007918,000063: # DEBRIS: A, L, Q AND DEBRIS OF NOVAC.
007919,000064:
007920,000065: # SUBROUTINE CALLED: NOVAC.
007921,000066:
007922,000067: 06,3164 1257 EBANK= CH5MASK
007923,000068:
007924,000069: 23,2000 BANK 23
007925,000070: 06,2000 SETLOC RCSMONT
007926,000071: 06,2000 BANK
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Page 192 |
007928,000073: 06,3164 COUNT* $$/T4RCS
007929,000074:
007930,000075: 06,3164 06,3164 RCSMONIT EQUALS RCSMON
007931,000076:
007932,000077: 06,3164 44755 RCSMON CS ZERO
007933,000078: 06,3165 00006 EXTEND
007934,000079: 06,3166 06032 RXOR CHAN32 # PICK UP + INVERT INVERTED CHANNEL 32.
007935,000080: 06,3167 74357 MASK LOW8 # KEEP JET-FAIL BITS ONLY.
007936,000081: 06,3170 54002 TS Q
007937,000082:
007938,000083: 06,3171 41273 CS PVALVEST # - -
007939,000084: 06,3172 70002 MASK Q # FORM PC + PC.
007940,000085: 06,3173 54001 TS L # (P = PREVIOUS ISOLATION VALVE STATE,
007941,000086: 06,3174 40002 CS Q # C = CURRENT VALVE STATE (CH32)).
007942,000087: 06,3175 71273 MASK PVALVEST
007943,000088: 06,3176 26001 ADS L # RESULT NZ INDICATES ACTION REQUIRED.
007944,000089:
007945,000090: 06,3177 00006 EXTEND
007946,000091: 06,3200 15270 BZF RCSMONEX # QUIT IF NO ACTION REQUIRED.
007947,000092:
007948,000093: 06,3201 00006 EXTEND
007949,000094: 06,3202 74745 MP BIT7 # MOVE BITS 8 - 1 OF A TO 14 - 7 OF L.
007950,000095: 06,3203 56001 XCH L # ZERO TO L IN THE PROCESS.
007951,000096:
007952,000097: 06,3204 24001 -3 INCR L
007953,000098: 06,3205 60000 DOUBLE # BOUND TO GET OVERFLOW IN THIS LOOP,
007954,000099: 06,3206 54000 OVSK # SINCE WE ASSURED INITIAL NZ IN A.
007955,000100: 06,3207 13204 TCF -3
007956,000101:
007957,000102: 06,3210 50001 INDEX L
007958,000103: 06,3211 34743 CA BIT8 -1 # SAVE THE RELEVANT BIT (8 - 1).
007959,000104: 06,3212 54002 TS Q
007960,000105: 06,3213 71273 MASK PVALVEST # LOOK AT PREVIOUS VALVE STATE BIT.
007961,000106: 06,3214 10000 CCS A
007962,000107: 06,3215 13231 TCF VOPENED # THE VALVE HAS JUST BEEN OPENED.
007963,000108:
007964,000109: 06,3216 41257 CS CH5MASK # THE VALVE HAS JUST BEEN CLOSED.
007965,000110: 06,3217 50001 INDEX L
007966,000111: 06,3220 73250 MASK 5FAILTAB
007967,000112: 06,3221 27257 ADS CH5MASK # SET INHIBIT BIT FOR CHANNEL 5 JET.
007968,000113:
007969,000114: 06,3222 41260 CS CH6MASK
007970,000115: 06,3223 50001 INDEX L
007971,000116: 06,3224 73260 MASK 6FAILTAB
007972,000117: 06,3225 27260 ADS CH6MASK # SET INGIBIT BIT FOR CHANNEL 6 JET.
007973,000118:
007974,000119: 06,3226 30002 CA Q
007975,000120: 06,3227 27273 ADS PVALVEST # RECORD ACTION TAKEN.
007976,000121:
007977,000122: 06,3230 13244 TCF 1/ACCFIX # SET UP 1/ACCJOB AND EXIT.
007978,000123:
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007980,000125: 06,3231 50001 VOPENED INDEX L # A VALVE HAS JUST BEEN OPENED.
007981,000126: 06,3232 43250 CS 5FAILTAB
007982,000127: 06,3233 71257 MASK CH5MASK
007983,000128: 06,3234 55257 TS CH5MASK # REMOVE INHIBIT BIT FOR CHANNEL 5 JET.
007984,000129:
007985,000130: 06,3235 50001 INDEX L
007986,000131: 06,3236 43260 CS 6FAILTAB
007987,000132: 06,3237 71260 MASK CH6MASK
007988,000133: 06,3240 55260 TS CH6MASK # REMOVE INHIBIT BIT FOR CHANNEL 6 JET.
007989,000134:
007990,000135: 06,3241 40002 CS Q
007991,000136: 06,3242 71273 MASK PVALVEST
007992,000137: 06,3243 55273 TS PVALVEST # RECORD ACTION TAKEN.
007993,000138:
007994,000139: 06,3244 37720 1/ACCFIX CAF PRIO27 # SET UP 1/ACCS SO THAT THE SWITCH CURVES
007995,000140: 06,3245 05072 TC NOVAC # FOR TJETLAW CAN BE MODIFIED IF CH5MASK
007996,000141: 06,3246 E6,1537 EBANK= AOSQ # HAS BEEN ALTERED.
007997,000142: 06,3246 03644 42106 2CADR 1/ACCJOB
007998,000143:
007999,000144: 06,3250 15270 TCF RCSMONEX # EXIT.
008000,000145:
008001,000146:
008002,000147: 06,3251 5FAILTAB EQUALS -1 # CH 5 JET BIT CORRESPONDING TO CH 32 BIT:
008003,000148: 06,3251 00040 OCT 00040 # 8
008004,000149: 06,3252 00020 OCT 00020 # 7
008005,000150: 06,3253 00100 OCT 00100 # 6
008006,000151: 06,3254 00200 OCT 00200 # 5
008007,000152: 06,3255 00010 OCT 00010 # 4
008008,000153: 06,3256 00001 OCT 00001 # 3
008009,000154: 06,3257 00004 OCT 00004 # 2
008010,000155: 06,3260 00002 OCT 00002 # 1
008011,000156:
008012,000157: 06,3261 6FAILTAB EQUALS -1 # CH 6 JET BIT CORRESPONDING TO CH 32 BIT:
008013,000158: 06,3261 00010 OCT 00010 # 8
008014,000159: 06,3262 00020 OCT 00020 # 7
008015,000160: 06,3263 00004 OCT 00004 # 6
008016,000161: 06,3264 00200 OCT 00200 # 5
008017,000162: 06,3265 00001 OCT 00001 # 4
008018,000163: 06,3266 00002 OCT 00002 # 3
008019,000164: 06,3267 00040 OCT 00040 # 2
008020,000165: 06,3270 00100 OCT 00100 # 1
End of include-file RCS_FAILURE_MONITOR.agc. Parent file is MAIN.agc