Source Code
007692,000001: # Copyright: Public domain.
007693,000002: # Filename: RCS_FAILURE_MONITOR.agc
007694,000003: # Purpose: Part of the source code for Luminary 1A build 099.
007695,000004: # It is part of the source code for the Lunar Module's (LM)
007696,000005: # Apollo Guidance Computer (AGC), for Apollo 11.
007697,000006: # Assembler: yaYUL
007698,000007: # Contact: Hartmuth Gutsche <hgutsche@xplornet.com>.
007699,000008: # Website: www.ibiblio.org/apollo.
007700,000009: # Pages: 190-192
007701,000010: # Mod history: 2009-05-19 HG Transcribed from page images.
007702,000011:
007703,000012: # This source code has been transcribed or otherwise adapted from
007704,000013: # digitized images of a hardcopy from the MIT Museum. The digitization
007705,000014: # was performed by Paul Fjeld, and arranged for by Deborah Douglas of
007706,000015: # the Museum. Many thanks to both. The images (with suitable reduction
007707,000016: # in storage size and consequent reduction in image quality as well) are
007708,000017: # available online at www.ibiblio.org/apollo. If for some reason you
007709,000018: # find that the images are illegible, contact me at info@sandroid.org
007710,000019: # about getting access to the (much) higher-quality images which Paul
007711,000020: # actually created.
007712,000021:
007713,000022: # Notations on the hardcopy document read, in part:
007714,000023:
007715,000024: # Assemble revision 001 of AGC program LMY99 by NASA 2021112-61
007716,000025: # 16:27 JULY 14, 1969
007717,000026:
007718,000027: # Page 190
007719,000028: # PROGRAM DESCRIPTION:
007720,000029:
007721,000030: # AUTHOR: J. S. MILLER
007722,000031:
007723,000032: # MODIFIED 6 MARCH 1968 BY P. S. WEISSMAN TO SET UP JOB FOR 1/ACCS WHEN THE MASKS ARE CHANGED.
007724,000033:
007725,000034: # THIS ROUTINE IS ATTACHED TO T4RUPT, AND IS ENTERED EVERY 480 MS. ITS FUNCTION IS TO EXAMINE THE LOW 8 BITS
007726,000035: # OF CHANNEL 32 TO SEE IF ANY ISOLATION-VALVE CLOSURE BITS HAVE APPEARED OR DISAPPEARED (THE CREW IS WARNED OF JET
007727,000036: # FAILURES BY LAMPS LIT BY THE GRUMMAN FAILURE-DETECTION CIRCUITRY; THEY MAY RESPOND BY OPERATING SWITCHES WHICH
007728,000037: # ISOLATE PAIRS OF JETS FROM THE PROPELLANT TANKS AND SET BITS IN CHANNEL 32). iN THE EVENT THAT CHANNEL 32 BITS
007729,000038: # DIFFER FROM `PVALVEST', THE RECORD OF ACTIONS TAKEN BY THIS ROUTINE, THE APPROPRIATE BITS IN `CH5MASK' &
007730,000039: # `CH6MASK', USED BY THE DAP JET-SELECTION LOGIC, ARE UPDATED, AS IS `PVALVEST'. TO SPEED UP & SHORTEN THE
007731,000040: # ROUTINE, NO MORE THAN ONE CHANGE IS ACCEPTED PER ENTRY. THE HIGHEST-NUMBERED BIT IN CHANNEL 32 WHICH REQUIRES
007732,000041: # ACTION IS THE ONE PROCESSED.
007733,000042:
007734,000043: # THE CODING IN THE FAILURE MONITOR HAS BEEN WRITTEN SO AS TO HAVE ALMOST COMPLETE RESTART PROTECTION. FOR
007735,000044: # EXAMPLE, NO ASSUMPTION IS MADE WHEN SETTING A `CH5MASK' BIT TO 1 THAT THE PREVIOUS STATE IS 0, ALTHOUGH IT OF
007736,000045: # COURSE SHOULD BE. ONE CASE WHICH MAY BE SEEN TO EVADE PROTECTION IS THE OCCURRENCE OF A RESTART AFTER UPDATING
007737,000046: # ONE OR BOTH DAP MASK-WORDS BUT BEFORE UPDATING `PVALVEST', COUPLED WITH A CHANGE IN THE VALVE-BIT BACK TO ITS
007738,000047: # FORMER STATE. THE CONSEQUENCE OF THIS IS THAT THE NEXT ENTRY WOULD NOT SEE THE CHANGE INCOMPLETELY INCORP-
007739,000048: # ORATED BY THE LAST PASS (BECAUSE IT WENT AWAY AT JUST THE RIGHT TIME), BUT THE DAP MASK-WORDS WILL BE INCORRECT.
007740,000049: # THIS COMBINATION OF EVENTS SEEMS QUITE REMOTE, BUT NOT IMPOSSIBLE UNLESS THE CREW OPERATES THE SWITCHES AT HALF-
007741,000050: # SECOND INTERVALS OR LONGER. IN ANY EVENT, A DISAGREEMENT BETWEEN REALITY AND THE DAP MASKS WILL BE CUREED IF
007742,000051: # THE MISINTERPRETED SWITCH IS REVERSED AND THEN RESTORED TO ITS CORRECT POSITION (SLOWLY).
007743,000052:
007744,000053: # CALLING SEQUENCE:
007745,000054:
007746,000055: # TCF RCSMONIT # (IN INTERRUPT MODE, EVERY 480 MS.)
007747,000056:
007748,000057: # EXIT: TCF RCSMONEX (ALL PATHS EXIT VIA SUCH AN INSTRUCTION)
007749,000058:
007750,000059: 06,3156 5270 RCSMONEX EQUALS RESUME
007751,000060:
007752,000061: # ERASABLE INITIALIZATION REQUIRED:
007753,000062:
007754,000063: # VIA FRESH START: PVALVEST = +0 (ALL JETS ENABLED)
007755,000064: # CH5MASK,CH6MASK = +0 (ALL JETS OK)
007756,000065:
007757,000066: # OUTPUT: CH5MASK & CH6MASK UPDATED (1'S WHERE JETS NOT TO BE USED, IN CHANNEL 5 & 6 FORMAT)
007758,000067: # PVALTEST UPDATED (1'S WHEN VALVE CLOSURES HAVE BEEN TRANSLATED INTO CH5MASK & CH6MASK; CHAN 32 FORMAT)
007759,000068: # JOB TO DO 1/ACCS.
007760,000069:
007761,000070: # DEBRIS: A, L, AND Q AND DEBRIS OF NOVAC.
007762,000071:
007763,000072: # SUBROUTINE CALLED: NOVAC.
007764,000073:
007765,000074: 06,3156 1262 EBANK= CH5MASK
007766,000075:
007767,000076: 23,2000 BANK 23
007768,000077: 06,2000 SETLOC RCSMONT
007769,000078: 06,2000 BANK
007770,000079: # Page 191
007771,000080: 06,3156 COUNT* $$/T4RCS
007772,000081:
007773,000082: 06,3156 06,3156 RCSMONIT EQUALS RCSMON
007774,000083:
007775,000084: 06,3156 44755 RCSMON CS ZERO
007776,000085: 06,3157 00006 EXTEND
007777,000086: 06,3160 06032 RXOR CHAN32 # PICK UP + INVERT INVERTED CHANNEL 32.
007778,000087: 06,3161 74357 MASK LOW8 # KEEP JET-FAIL BITS ONLY.
007779,000088: 06,3162 54002 TS Q
007780,000089:
007781,000090: 06,3163 41276 CS PVALVEST # _ _
007782,000091: 06,3164 70002 MASK Q # FORM PC + PC.
007783,000092: 06,3165 54001 TS L # (P = PREVIOUS ISOLATION VALVE STATE,
007784,000093: 06,3166 40002 CS Q # C = CURRENT VALVE STATE (CH32)).
007785,000094: 06,3167 71276 MASK PVALVEST
007786,000095: 06,3170 26001 ADS L # RESULT NZ INDICATES ACTION REQUIRED.
007787,000096:
007788,000097: 06,3171 00006 EXTEND
007789,000098: 06,3172 15270 BZF RCSMONEX # QUIT IF NO ACTION REQUIRED.
007790,000099:
007791,000100: 06,3173 00006 EXTEND
007792,000101: 06,3174 74745 MP BIT7 # MOVE BITS 8-1 OF A TO 14-7 OF L.
007793,000102: 06,3175 56001 XCH L # ZERO TO L IN THE PROCESS.
007794,000103:
007795,000104: 06,3176 24001 -3 INCR L
007796,000105: 06,3177 60000 DOUBLE # BOUND TO GET OVERFLOW IN THIS LOOP,
007797,000106: 06,3200 54000 OVSK # SINCE WE ASSURED INITIAL NZ IN A.
007798,000107: 06,3201 13176 TCF -3
007799,000108:
007800,000109: 06,3202 50001 INDEX L
007801,000110: 06,3203 34743 CA BIT8 -1 # SAVE THE RELEVANT BIT (8-1).
007802,000111: 06,3204 54002 TS Q
007803,000112: 06,3205 71276 MASK PVALVEST # LOOK AT PREVIOUS VALVE STATE BIT.
007804,000113: 06,3206 10000 CCS A
007805,000114: 06,3207 13223 TCF VOPENED # THE VALVE HAS JUST BEEN OPENED.
007806,000115:
007807,000116: 06,3210 41262 CS CH5MASK # THE VALVE HAS JUST BEEN CLOSED.
007808,000117: 06,3211 50001 INDEX L
007809,000118: 06,3212 73242 MASK 5FAILTAB
007810,000119: 06,3213 27262 ADS CH5MASK # SET INHIBIT BIT FOR CHANNEL 5 JET.
007811,000120:
007812,000121: 06,3214 41263 CS CH6MASK
007813,000122: 06,3215 50001 INDEX L
007814,000123: 06,3216 73252 MASK 6FAILTAB
007815,000124: 06,3217 27263 ADS CH6MASK # SET INGIBIT BIT FOR CHANNEL 6 JET
007816,000125:
007817,000126: 06,3220 30002 CA Q
007818,000127: 06,3221 27276 ADS PVALVEST # RECORD ACTION TAKEN.
007819,000128:
007820,000129: 06,3222 13236 TCF 1/ACCFIX # SET UP 1/ACCJOB AND EXIT.
007821,000130:
007822,000131: # Page 192
007823,000132: 06,3223 50001 VOPENED INDEX L # A VALVE HAS JUST BEEN OPENED.
007824,000133: 06,3224 43242 CS 5FAILTAB
007825,000134: 06,3225 71262 MASK CH5MASK
007826,000135: 06,3226 55262 TS CH5MASK # REMOVE INHIBIT BIT FOR CHANNEL 5 JET.
007827,000136:
007828,000137: 06,3227 50001 INDEX L
007829,000138: 06,3230 43252 CS 6FAILTAB
007830,000139: 06,3231 71263 MASK CH6MASK
007831,000140: 06,3232 55263 TS CH6MASK # REMOVE INHIBIT BIT FOR CHANNEL 6 JET.
007832,000141:
007833,000142: 06,3233 40002 CS Q
007834,000143: 06,3234 71276 MASK PVALVEST
007835,000144: 06,3235 55276 TS PVALVEST # RECORD ACTION TAKEN.
007836,000145:
007837,000146: 06,3236 37715 1/ACCFIX CAF PRIO27 # SET UP 1/ACCS SO THAT THE SWITCH CURVES
007838,000147: 06,3237 05072 TC NOVAC # FOR TJETLAW CAN BE MODIFIED IF CH5MASK
007839,000148: 06,3240 E6,1537 EBANK= AOSQ # HAS BEEN ALTERED.
007840,000149: 06,3240 02454 40106 2CADR 1/ACCJOB
007841,000150:
007842,000151: 06,3242 15270 TCF RCSMONEX # EXIT.
007843,000152:
007844,000153: 06,3243 5FAILTAB EQUALS -1 # CH 5 JET BIT CORRESPONDING TO CH 32 BIT:
007845,000154: 06,3243 00040 OCT 00040 # 8
007846,000155: 06,3244 00020 OCT 00020 # 7
007847,000156: 06,3245 00100 OCT 00100 # 6
007848,000157: 06,3246 00200 OCT 00200 # 5
007849,000158: 06,3247 00010 OCT 00010 # 4
007850,000159: 06,3250 00001 OCT 00001 # 3
007851,000160: 06,3251 00004 OCT 00004 # 2
007852,000161: 06,3252 00002 OCT 00002 # 1
007853,000162:
007854,000163: 06,3253 6FAILTAB EQUALS -1 # CH 6 JET BIT CORRESPONDING TO CH 32 BIT:
007855,000164: 06,3253 00010 OCT 00010 # 8
007856,000165: 06,3254 00020 OCT 00020 # 7
007857,000166: 06,3255 00004 OCT 00004 # 6
007858,000167: 06,3256 00200 OCT 00200 # 5
007859,000168: 06,3257 00001 OCT 00001 # 4
007860,000169: 06,3260 00002 OCT 00002 # 3
007861,000170: 06,3261 00040 OCT 00040 # 2
007862,000171: 06,3262 00100 OCT 00100 # 1
007863,000172:
007864,000173:
End of include-file RCS_FAILURE_MONITOR.agc. Parent file is MAIN.agc