Source Code
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These source-code files were derived originally from the scan from MIT's Dibner Institute's
now-discontinued website titled "History of Recent Science and Technology". It is believed
that the original listing was preserved by AGC developer Don Eyles, copied/reduced by
AGC developer Hugh Blair-Smith, passed by AGC developer James Kernan to collector David Craig,
scanned by Gary Neff, and then passed to the Dibner Institute
where unfortunately the high-quality scans were reduced in legibility as part of the
online-presentation process, and the original scans discarded.
The source code was transcribed from
those images by Ron Burkey. The images from the Dibner Institute website, and unfortunately not
the discarded original high-quality scans, though with a few high-quality replacement scans
provided directly by Gary Neff, are now available
at the Virtual AGC project website.
Report any conversion errors to info@sandroid.org.
Notations on the program listing read, in part:GAP: ASSEMBLE REVISION 131 OF AGC PROGRAM LUMINARY BY NASA 2021112-091 17:53 DEC. 19, 1969Note that the date is the date of the printout, not the date of the program revision. |
019976,000002: ## Copyright: Public domain.
019977,000003: ## Filename: R60_62.agc
019978,000004: ## Purpose: A section of Luminary 1C, revision 131.
019979,000005: ## It is part of the source code for the Lunar Module's (LM)
019980,000006: ## Apollo Guidance Computer (AGC) for Apollo 13 and Apollo 14.
019981,000007: ## This file is intended to be a faithful transcription, except
019982,000008: ## that the code format has been changed to conform to the
019983,000009: ## requirements of the yaYUL assembler rather than the
019984,000010: ## original YUL assembler.
019985,000011: ## Reference: pp. 481-494 of 1729.pdf.
019986,000012: ## Contact: Ron Burkey <info@sandroid.org>.
019987,000013: ## Website: www.ibiblio.org/apollo/index.html
019988,000014: ## Mod history: 05/14/03 RSB. Began transcribing.
019989,000015: ## 05/14/05 RSB Corrected website reference above.
019990,000016:
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Page 481 |
019992,000018: # MOD NO: 0 DATE: 1 MAY 1968
019993,000019: # MOD BY: DIGITAL DEVEL GROUP LOG SECTION R60,R62
019994,000020:
019995,000021: # FUNCTIONAL DESCRIPTION:
019996,000022:
019997,000023: # CALLED AS A GENERAL SUBROUTINE TO MANEUVER THE LM TO A SPECIFIED
019998,000024: # ATTITUDE.
019999,000025:
020000,000026: # 1. IF THE 3-AXIS FLAG IS NOT SET THE FINAL CDU ANGLES ARE
020001,000027: # CALCULATED (VECPOINT).
020002,000028:
020003,000029: # 2. THE FDAI BALL ANGLES (NOUN 18) ARE CALCULATED (BALLANGS).
020004,000030:
020005,000031: # 3. REQUEST FLASHING DISPLAY V50 N18 PLEASE PERFORM AUTO MANEUVER.
020006,000032:
020007,000033: # 4. IF PRIORITY DISPLAY FLAG IS SET TO A PHASECHANGE. THEN AWAIT
020008,000034: # ASTRONAUT RESPONSE.
020009,000035:
020010,000036: # 5. DISPLAY RESPONSE RETURNS.
020011,000037:
020012,000038: # A. ENTER -- RESET 3-AXIS FLAG AND RETURN TO CLIENT.
020013,000039:
020014,000040: # B. TERMINATE -- IF IN P00 GO TO STEP 5A. OTHERWISE CHECK IF R61 IS
020015,000041: # THE CALLING PROGRAM. IF IN R61 AN EXIT IS MADE TO GOTOV56. IF
020016,000042: # NOT IN R61 AND EXIT IS DONE VIA GOTOP00H.
020017,000043:
020018,000044: # C. PROCEED -- CONTINUE WITH PROGRAM AT STEP 6.
020019,000045:
020020,000046: # 6. IF THE 3-AXIS FLAG IS NOT SET, THE FINAL CDU ANGLES ARE CALCULATED
020021,000047: # (VECPOINT).
020022,000048:
020023,000049: # 7. THE FDAI BALL ANGLES (NOUN 18) ARE CALCULATED (BALLANGS).
020024,000050:
020025,000051: # 8. IF THE G+N SWITCH IS NOT SET GO BACK TO STEP 3.
020026,000052: #
020027,000053: # 9. IF THE AUTO SWITCH IS NOT SET GO BACK TO STEP 3.
020028,000054:
020029,000055: # 10. NON-FLASHING DISPLAY V06N18 (FDAI ANGLES).
020030,000056:
020031,000057: # 11. DO A PHASE-CHANGE.
020032,000058:
020033,000059: # 12. DO A MANEUVER CALCULATION AND ICDU DRIVE ROUTINE TO ACHIEVE FINAL
020034,000060: # GIMBAL ANGLES (GOMANUR).
020035,000061:
020036,000062: # 13. AT END OF MANEUVER TO TO STEP 3.
020037,000063:
020038,000064: # IF SATISFACTORY MANEUVER STEP 5A EXITS R60.
020039,000065: # FOR FURTHER ADJUSTMENT OF THE VEHICLE ATTITUDE ABOUT THE
020040,000066: # DESIRED VECTOR, THE ROUTINE MAY BE PERFORMED AGAIN STARTING AT
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020042,000068: # STEP 5C.
020043,000069:
020044,000070: # CALLING SEQUENCE: TC BANKCALL
020045,000071: # CADR R60LEM
020046,000072:
020047,000073: # ERASABLE INITIALIZATION REQUIRED: SCAXIS, POINTVSM (FOR VECPOINT)
020048,000074: # 3AXISFLG.
020049,000075:
020050,000076: # SUBROUTINES CALLED: VECPOINT, BALLANGS, GOPERF24, LINUS, GOSPER,
020051,000077: # GOMANUR, DOWNFLAG, PHASCHNG, UPFLAG
020052,000078:
020053,000079: # NORMAL EXIT MODES: CAE TEMPR60 (CALLER'S RETURN ADDRESS)
020054,000080: # TC BANKJUMP
020055,000081:
020056,000082: # ALARMS: NONE
020057,000083:
020058,000084: # OUTPUT: NONE
020059,000085:
020060,000086: # DEBRIS: CPHI, CTHETA, CPSI, 3AXISFLG, TBASE2
020061,000087:
020062,000088: 34,2000 BANK 34
020063,000089: 26,2000 SETLOC MANUVER
020064,000090: 26,2000 BANK
020065,000091:
020066,000092: 26,2123 1163 EBANK= TEMPR60
020067,000093:
020068,000094: 26,2123 COUNT* $$/R06
020069,000095: 26,2123 04645 R60LEM TC MAKECADR
020070,000096: 26,2124 55163 TS TEMPR60
020071,000097:
020072,000098: 26,2125 34746 REDOMANN CAF 3AXISBIT
020073,000099: 26,2126 70101 MASK FLAGWRD5 # IS 3-AXIS FLAG SET
020074,000100: 26,2127 10000 CCS A
020075,000101: 26,2130 12136 TCF TOBALL # YES
020076,000102: 26,2131 06042 TC INTPRET
020077,000103: 26,2132 77624 CALL
020078,000104: 26,2133 56040 VECPOINT # TO COMPUTE FINAL ANGLES
020079,000105: 26,2134 00322 STORE CPHI # STORE FINAL ANGLES -- CPHI, CTHETA, CPSI
020080,000106: 26,2135 77776 EXIT
020081,000107:
020082,000108: 26,2136 05504 TOBALL TC UPFLAG # INSURE THAT TOTAL ATTITUDE ERRORS ARE
020083,000109: 26,2137 00013 ADRES NEEDLFLG # DISPLAYED ON FDAI ERROR NEEDLES
020084,000110: 26,2140 05516 TC DOWNFLAG
020085,000111: 26,2141 00000 ADRES NEED2FLG
020086,000112: 26,2142 04616 TC BANKCALL
020087,000113: 26,2143 54272 CADR BALLANGS # TO CONVERT ANGLES TO FDAI
020088,000114: 26,2144 32260 TOBALLA CAF V06N18
020089,000115: 26,2145 04616 TC BANKCALL
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020091,000117: 26,2146 20711 CADR GOPERF2R # DISPLAY PLEASE PERFORM AUTO MANEUVER
020092,000118: 26,2147 02246 TC R61TEST
020093,000119: 26,2150 02154 TC REDOMANC # PROCEED
020094,000120: 26,2151 02201 TC ENDMANU1 # ENTER I.E., FINISHED WITH R60
020095,000121: 26,2152 02205 TC CHKLINUS # TO CHECK FOR PRIORITY DISPLAYS
020096,000122: 26,2153 05155 TC ENDOFJOB
020097,000123:
020098,000124: 26,2154 34746 REDOMANC CAF 3AXISBIT
020099,000125: 26,2155 70101 MASK FLAGWRD5 # IS 3-AXIS FLAG SET
020100,000126: 26,2156 10000 CCS A
020101,000127: 26,2157 12165 TCF TOBALLC # YES
020102,000128: 26,2160 06042 TC INTPRET
020103,000129: 26,2161 77624 CALL
020104,000130: 26,2162 56040 VECPOINT # TO COMPUTE FINAL ANGLES
020105,000131: 26,2163 00322 STORE CPHI # STORE ANGLES
020106,000132: 26,2164 77776 EXIT
020107,000133:
020108,000134: 26,2165 04616 TOBALLC TC BANKCALL
020109,000135: 26,2166 54272 CADR BALLANGS # TO CONVERT ANGLES TO FDAI
020110,000136: 26,2167 02261 TC G+N,AUTO # CHECK AUTO MODE
020111,000137: 26,2170 10000 CCS A
020112,000138: 26,2171 12144 TCF TOBALLA # NOT AUTO, GO REREQUEST AUTO MANEUVER.
020113,000139:
020114,000140: 26,2172 32260 AUTOMANV CAF V06N18 # STATIC DISPLAY DURING AUTO MANEUVER
020115,000141: 26,2173 04616 TC BANKCALL
020116,000142: 26,2174 20452 CADR GODSPR
020117,000143: 26,2175 02205 TC CHKLINUS # TO CHECK FOR PRIORITY DISPLAYS
020118,000144:
020119,000145: 26,2176 04616 STARTMNV TC BANKCALL # PERFORM MANEUVER VIA KALCMANU
020120,000146: 26,2177 17741 CADR GOMANUR
020121,000147:
020122,000148: 26,2200 12144 ENDMANUV TCF TOBALLA # FINISHED MANEUVER.
020123,000149: 26,2201 05516 ENDMANU1 TC DOWNFLAG # RESET 3-AXIS FLAG
020124,000150: 26,2202 00124 ADRES 3AXISFLG
020125,000151: 26,2203 31163 CAE TEMPR60
020126,000152: 26,2204 04640 TC BANKJUMP
020127,000153:
020128,000154: 26,2205 40100 CHKLINUS CS FLAGWRD4
020129,000155: 26,2206 74740 MASK PDSPFBIT # IS PRIORITY DISPLAY FLAG SET?
020130,000156: 26,2207 10000 CCS A
020131,000157: 26,2210 00002 TC Q # NO -- EXIT
020132,000158: 26,2211 30002 CA Q
020133,000159: 26,2212 54156 TS MPAC +2 # SAVE RETURN
020134,000160: 26,2213 46250 CS THREE # OBTAIN LOCATION FOR RESTART
020135,000161: 26,2214 60133 AD BUF2 # HOLD Q OF LAST DISPLAY
020136,000162: 26,2215 55054 TS TBASE2
020137,000163:
020138,000164: 26,2216 05353 TC PHASCHNG
020139,000165: 26,2217 00132 OCT 00132
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020141,000167: 26,2220 34745 CAF BIT7
020142,000168: 26,2221 05464 TC LINUS # GO SET BITS FOR PRIORITY DISPLAY
020143,000169: 26,2222 00156 TC MPAC +2
020144,000170:
020145,000171: 26,2223 37717 RELINUS CAF PRIO26 # RESTORE ORIGINAL PRIORITY
020146,000172: 26,2224 05146 TC PRIOCHNG
020147,000173:
020148,000174: 26,2225 34747 CAF TRACKBIT # DON'T CONTINUE R60 UNLESS TRACKFLAG ON.
020149,000175: 26,2226 70075 MASK FLAGWRD1
020150,000176: 26,2227 10000 CCS A
020151,000177: 26,2230 12243 TCF RER60
020152,000178:
020153,000179: 26,2231 34745 CAF RNDVZBIT # IS IT P20?
020154,000180: 26,2232 70074 MASK FLAGWRD0
020155,000181: 26,2233 10000 CCS A
020156,000182: 26,2234 02240 TC +4 # YES
020157,000183: 26,2235 05353 TC PHASCHNG # NO, MUST BE P25, SET 2.11 SPOT
020158,000184: 26,2236 40112 OCT 40112
020159,000185:
020160,000186: 26,2237 05155 TC ENDOFJOB
020161,000187:
020162,000188: 26,2240 05353 TC PHASCHNG # SET 2.7 SPOT FOR P20
020163,000189: 26,2241 40072 OCT 40072
020164,000190:
020165,000191: 26,2242 05155 TC ENDOFJOB
020166,000192:
020167,000193: 26,2243 05504 RER60 TC UPFLAG # SET PRIO DISPLAY FLAG AFTER RESTART
020168,000194: 26,2244 00077 ADRES PDSPFLAG
020169,000195:
020170,000196: 26,2245 01054 TC TBASE2
020171,000197:
020172,000198: 26,2246 31010 R61TEST CA MODREG # IF WE ARE IN P00 IT MUST BE V49 OR V89
020173,000199: 26,2247 00006 EXTEND
020174,000200: 26,2250 12201 BZF ENDMANU1 # THUS WE GO TO ENDEXT VIA USER
020175,000201:
020176,000202: 26,2251 30100 CA FLAGWRD4 # ARE WE IN R61 (P20 OR garbled)
020177,000203: 26,2252 74740 MASK PDSPFBIT
020178,000204: 26,2253 00006 EXTEND
020179,000205: 26,2254 16001 BZF GOTOP00H # NO
020180,000206: 26,2255 06025 TC GOTOV56 # YES
020181,000207:
020182,000208: 26,2256 20100 BIT14+7 OCT 20100
020183,000209: 26,2257 00203 OCT203 OCT 203
020184,000210: 26,2260 01422 V06N18 VN 0618
020185,000211:
020186,000212: # SUBROUTINE TO CHECK FOR G+N CONTROL, AUTO STABILIZATION
020187,000213:
020188,000214: # RETURNS WITH C(A) = + IF NOT SET FOR G+N, AUTO
020189,000215: # RETURNS WITH C(A) = +0 IF SWITCHES ARE SET
020190,000216:
020191,000217: 26,2261 00006 G+N,AUTO EXTEND
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020193,000219: 26,2262 00030 READ CHAN30
020194,000220: 26,2263 74742 MASK BIT10
020195,000221: 26,2264 10000 CCS A
020196,000222: 26,2265 00002 TC Q # NOT IN G+N C(A) = -
020197,000223: 26,2266 00006 ISITAUTO EXTEND # CHECK FOR AUTO MODE
020198,000224: 26,2267 00031 READ CHAN31
020199,000225: 26,2270 74736 MASK BIT14
020200,000226: 26,2271 00002 TC Q # (+) = NOT IN AUTO, (+0) = AOK
020201,000227:
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020203,000229: # PROGRAM DESCRIPTION BALLANGS
020204,000230: # MOD NO. LOG SECTION R60,R62
020205,000231: # WRITTEN BY RAMA M. AIYAWAR
020206,000232:
020207,000233: # FUNCTIONAL DESCRIPTION
020208,000234:
020209,000235: # COMPUTES LM FDAI BALL DISPLAY ANGLES
020210,000236:
020211,000237: # CALLING SEQUENCE
020212,000238:
020213,000239: # TC BALLANGS
020214,000240:
020215,000241: # NORMAL EXIT MODE
020216,000242:
020217,000243: # TC BALLEXIT # (SAVED Q)
020218,000244:
020219,000245: # ALARM OR EXIT MODE: NIL
020220,000246:
020221,000247: # SUBROUTINES CALLED
020222,000248:
020223,000249: # CD*TR*G
020224,000250: # ARCTAN
020225,000251:
020226,000252: # INPUT
020227,000253:
020228,000254: # CPHI,CTHETA,CPSI ARE THE ANGLES CORRESPONDING TO AOG, AIG, AMG. THEY ARE
020229,000255: # SP,2'S COMPLEMENT SCALED TO HALF REVOLUTION.
020230,000256:
020231,000257: # OUTPUT
020232,000258:
020233,000259: # FDAIX, FDAIY, FDAIZ ARE THE REQUIRED BALL ANGLES SCALED TO HALF REVOLUTION
020234,000260: # SP,2'S COMPEMENT.
020235,000261:
020236,000262: # THESE ANGLES WILL BE DISPLAYED AS DEGREES AND HUNDREDTHS, IN THE ORDER ROLL, PITCH, YAW, USING NOUNS 18 & 19.
020237,000263:
020238,000264: # ERASABLE INITIALIZATION REQUIRED
020239,000265:
020240,000266: # CPHI, CTHETA, CPSI EACH AN SP REGISTER
020241,000267:
020242,000268: # DEBRIS
020243,000269:
020244,000270: # A,L,Q,MPAC,SINCDU,COSCDU,PUSHLIST,BALLEXIT
020245,000271:
020246,000272: # NOMENCLATURE: CPHI, CTHETA, & CPSI REPRESENT THE OUTER, INNER, AND MIDDLE GIMBAL ANGLES, RESPECTIVELY; OR
020247,000273: # EQUIVALENTLY, CDUX, CDUY, AND CDUZ.
020248,000274:
020249,000275: # NOTE: ARCTAN CHECKS FOR OVERFLOW AND SHOULD BE ABLE TO HANDLE ANY SINGULARITIES.
020250,000276:
020251,000277: 26,2000 SETLOC BAWLANGS
020252,000278: 26,2000 BANK
020253,000279:
020254,000280: 26,2272 COUNT* $$/BALL
020255,000281: 26,2272 04645 BALLANGS TC MAKECADR
020256,000282: 26,2273 55337 TS BALLEXIT
020257,000283: 26,2274 30321 CA CPHI
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020259,000285: 26,2275 54771 TS CDUSPOT +4
020260,000286: 26,2276 30322 CA CTHETA
020261,000287: 26,2277 54765 TS CDUSPOT
020262,000288: 26,2300 30323 CA CPSI
020263,000289: 26,2301 54767 TS CDUSPOT +2
020264,000290:
020265,000291: 26,2302 06042 TC INTPRET
020266,000292: 26,2303 45001 SETPD CALL
020267,000293: 26,2304 00001 0D
020268,000294: 26,2305 47545 CD*TR*G
020269,000295:
020270,000296: 26,2306 41345 DLOAD DMP
020271,000297: 26,2307 00742 SINCDUX # SIN (OGA)
020272,000298: 26,2310 00746 COSCDUZ # COS (MGA)
020273,000299:
020274,000300: 26,2311 57552 SL1 DCOMP # SCALE
020275,000301: 26,2312 65336 ARCSIN PDDL # YAW = ARCSIN(-SXCZ) INTO 0 PD
020276,000302: 26,2313 00740 SINCDUZ
020277,000303: 26,2314 14023 STODL SINTH # (SINTH = 18D IN PD)
020278,000304: 26,2315 00746 COSCDUZ
020279,000305: 26,2316 72405 DMP SL1 # RESCALE
020280,000306: 26,2317 00750 COSCDUX
020281,000307: 26,2320 34021 STCALL COSTH # (COSTH = 16D IN PD)
020282,000308: 26,2321 26506 ARCTAN
020283,000309: 26,2322 41325 PDDL DMP # ROLL = ARCTAN(SZ/CZCX) INTO 2 PD
020284,000310: 26,2323 00740 SINCDUZ
020285,000311: 26,2324 00742 SINCDUX
020286,000312: 26,2325 41512 SL2 PUSH # SXSZ INTO 4 PD
020287,000313: 26,2326 65205 DMP PDDL # SXSZCY INTO 4 PD
020288,000314: 26,2327 00744 COSCDUY
020289,000315: 26,2330 65205 DMP PDDL # SXSZSY INTO 6 PD
020290,000316: 26,2331 00736 SINCDUY
020291,000317: 26,2332 00750 COSCDUX
020292,000318: 26,2333 72405 DMP SL1 # CXCY
020293,000319: 26,2334 00744 COSCDUY
020294,000320: 26,2335 45425 DSU STADR # PULL UP FORM 6 PD
020295,000321: 26,2336 63756 STODL COSTH # COSTH = CXCY - SXSZSY
020296,000322: 26,2337 00736 SINCDUY
020297,000323: 26,2340 72405 DMP SL1
020298,000324: 26,2341 00750 COSCDUX # CXSY
020299,000325: 26,2342 45415 DAD STADR # PULL UP FORM 4 PD
020300,000326: 26,2343 43754 STCALL SINTH # SINTH = CXSY + SXSZCY
020301,000327: 26,2344 26506 ARCTAN # RETURNS WITH D(MPAC) = PITCH
020302,000328: 26,2345 55525 PDDL VDEF # PITCH INTO 2 PD, ROLL INTO MPAC FROM 2 PD
020303,000329: 26,2346 77634 RTB # VDEF MAKES V(MPAC) = ROLL, PITCH, YAW
020304,000330: 26,2347 21621 V1STO2S
020305,000331: 26,2350 02345 STORE FDAIX # MODE IS TP
020306,000332: 26,2351 77776 EXIT
020307,000333:
020308,000334: 26,2352 31337 ENDBALL CA BALLEXIT
020309,000335:
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020311,000337: 26,2353 04640 TC BANKJUMP
020312,000338:
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020314,000340: # PROGRAM DESCRIPTION -- VECPOINT
020315,000341:
020316,000342: # THIS INTERPRETIVE SUBROUTINE MAY BE USED TO POINT A SPACECRAFT AXIS IN A DESIRED DIRECTION. THE AXIS
020317,000343: # TO BE POINTED MUST APPEAR AS A HALF UNIT DOUBLE PRECISION VECTOR IN SUCCESSIVE LOCATIONS OF ERASABLE MEMORY
020318,000344: # BEGINNING WITH THE LOCATION CALLED SCAXIS. THE COMPONENTS OF THIS VECTOR ARE GIVEN IN SPACECRAFT COORDINATES.
020319,000345: # THE DIRECTION IN WHICH THIS AXIS IS TO BE POINTED MUST APPEAR AS A HALF UNIT DOUBLE PRECISION VECTOR IN
020320,000346: # SUCCESSIVE LOCATIONS OF ERASABLE MEMORY BEGINNING WITH THE ADDRESS CALLED POINTVSM. THE COMPONENTS OF THIS
020321,000347: # VECTOR ARE GIVEN IN STABLE MEMBER COORDINATES. WITH THIS INFORMTION VECPOINT COMPUTES A SET OF THREE GIMBAL
020322,000348: # ANGLES (2'S COMPLEMENT) CORRESPONDING TO THE CROSS-PRODUCT ROTATION BETWEEN SCAXIS AND POINTVSM AND STORES THEM
020323,000349: # IN T(MPAC) BEFORE RETURNING TO THE CALLER.
020324,000350:
020325,000351: # THIS ROTATION, HOWEVER, MAY BRING THE S/C INTO GIMBAL LOCK. WHEN POINTING A VECTOR IN THE Y-Z PLANE,
020326,000352: # THE TRANSPONDER AXIS, OR THE AOT FOR THE LEM, THE PROGRAM WILL CORRECT THIS PROGLEM BY ROTATING THE CROSS-
020327,000353: # PRODUCT ATTITUDE ABOUT POINTVSM BY A FIXED AMOUNT SUFFICIENT TO ROTATE THE DESIRED S/C ATTITUDE OUT OF GIMBAL
020328,000354: # LOCK. IF THE AXIS TO BE POINTED IS MORE THAN 40.6 DEGREES BUT LESS THAN 60.5 DEG FROM THE +X (OR -X) AXIS,
020329,000355: # THE ADDITIONAL ROTATION TO AVOID GIMBAL LOCK IS 35 DEGREES. IF THE AXIS IS MORE THAN 60.5 DEGREES FROM +X (OR -X)
020330,000356: # THE ADDITIONAL ROTATION IS 35 DEGREES. THE GIMBAL ANGLES CORRESPONDING TO THIS ATTITUDE ARE THEN COMPUTED AND
020331,000357: # STORED AS 2'S COMPLEMENT ANGLES N T(MPAC) BEFORE RETURNING TO THE CALLER.
020332,000358:
020333,000359: # WHEN POINTING THE X-AXIS, OR THE THRUST VECTOR, OR ANY VECTOR WITHIN 40.6 DEG OF THE X-AXIS, VECPOINT
020334,000360: # CANNOT CORRECT FOR A CROSS-PRODUCT ROTATION INTO GIMBAL LOCK. IN THIS CASE A PLATFORM REALIGNMENT WOULD BE
020335,000361: # REQUIRED TO POINT THE VECTOR IN THE DESIRED DIRECTION. AT PRESENT NO INDICATION IS GIVEN FOR THIS SITUATION
020336,000362: # EXCEPT THAT THE FINAL MIDDLE GIMBAL ANGLE IN MPAC +2 IS GREATER THAN 59 DEGREES.
020337,000363:
020338,000364: # CALLING SEQUENCE
020339,000365:
020340,000366: # 1) LOAD SCAXIS, POINTVSM
020341,000367: # 2) CALL
020342,000368: # VECPOINT
020343,000369:
020344,000370: # RETURNS WITH
020345,000371:
020346,000372: # 1) DESIRED OUTER GIMBAL ANGLE IN MPAC
020347,000373: # 2) DESIRED INNER GIMBAL ANGLE IN MPAC +1
020348,000374: # 3) DESIRED MIDDLE GIMBAL ANGLE IN MPAC +2
020349,000375:
020350,000376: # ERASABLES USED --
020351,000377:
020352,000378: # 1) SCAXIS 6
020353,000379: # 2) POINTVSM 6
020354,000380: # 3) MIS 18
020355,000381: # 4) DEL 18
020356,000382: # 5) COF 6
020357,000383: # 6) VECQTEMP 1
020358,000384: # 7) ALL OF VAC AREA 43
020359,000385:
020360,000386: # TOTAL 99
020361,000387:
020362,000388: 27,2000 SETLOC VECPT
020363,000389: 27,2000 BANK
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020365,000391: 27,2032 COUNT* $$/VECPT
020366,000392:
020367,000393: 27,2032 E6,1675 EBANK= BCDU
020368,000394:
020369,000395: 27,2032 40020 VECPNT1 STQ BOV # THIS ENTRY USES DESIRED CDUS
020370,000396: 27,2033 03324 VECQTEMP # NOT PRESENT -- ENTER WITH CDUD'S IN MPAC
020371,000397: 27,2034 56035 VECPNT2
020372,000398: 27,2035 52164 VECPNT2 AXC,2 GOTO
020373,000399: 27,2036 03245 MIS
020374,000400: 27,2037 56046 STORANG
020375,000401: 27,2040 40020 VECPOINT STQ BOV # SAVE RETURN ADDRESS
020376,000402: 27,2041 03324 VECQTEMP
020377,000403: 27,2042 56043 VECLEAR # AND CLEAR OVFIND
020378,000404: 27,2043 47164 VECLEAR AXC,2 RTB
020379,000405: 27,2044 03245 MIS # READ THE PRESENT CDU ANGLES AND
020380,000406: 27,2045 44403 READCDUK # STORE THEM IN PD25, 26, 27
020381,000407: 27,2046 34032 STORANG STCALL 25D
020382,000408: 27,2047 44410 CDUTODCM # S/C AXES TO STABLE MEMBER AXES (MIS)
020383,000409: 27,2050 61375 VLOAD VXM
020384,000410: 27,2051 03773 POINTVSM # RESOLVE THE POINTING DIRECTION VF INTO
020385,000411: 27,2052 03246 MIS # INITIAL S/C AXES (VF = POINTVSM)
020386,000412: 27,2053 77656 UNIT
020387,000413: 27,2054 00035 STORE 28D
020388,000414: # PD 28 29 30 31 32 33
020389,000415: 27,2055 53435 VXV UNIT # TAKE THE CROSS PRODUCT VF X VI
020390,000416: 27,2056 03765 SCAXIS # WHERE VI = SCAXIS
020391,000417: 27,2057 57400 BOV VCOMP
020392,000418: 27,2060 56170 PICKAXIS
020393,000419: 27,2061 17270 STODL COF # CHECK MAGNITUDE
020394,000420: 27,2062 00045 36D # OF CROSS PRODUCT
020395,000421: 27,2063 50025 DSU BMN # VECTOR, IF LESS
020396,000422: 27,2064 14415 DPB-14 # THAN B-14 ASSUME
020397,000423: 27,2065 56170 PICKAXIS # UNIT OPERATION
020398,000424: 27,2066 50375 VLOAD DOT # INVALID.
020399,000425: 27,2067 03765 SCAXIS
020400,000426: 27,2070 00035 28D
020401,000427: 27,2071 65552 SL1 ARCCOS
020402,000428: 27,2072 77624 COMPMATX CALL # NO COMPUTE THE TRANSFORMATION FROM
020403,000429: 27,2073 44527 DELCOMP # FINAL S/C AXES TO INITIAL S/C AXES MFI
020404,000430: 27,2074 75160 AXC,1 AXC,2
020405,000431: 27,2075 03245 MIS # COMPUTE THE TRANSFORMATION FROM FINAL
020406,000432: 27,2076 02230 KEL # S/C AXES TO STABLE MEMBER AXES
020407,000433: 27,2077 77624 CALL # MFS = MIS MFI
020408,000434: 27,2100 44312 MXM3 # (IN PD LIST)
020409,000435:
020410,000436: 27,2101 51545 DLOAD ABS
020411,000437: 27,2102 00007 6 # MFS6 = SIN(CPSI)
020412,000438: 27,2103 50025 DSU BMN
020413,000439: 27,2104 14402 SINGIMLC # = SIN(59 DEGS)
020414,000440: 27,2105 56160 FINDGIMB # /CPSI/ LESS THAN 59 DEGS.
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Page 491 |
020416,000442: # I.E., DESIRED ATTITUDE NOT IN GIMBAL LOCK
020417,000443:
020418,000444: 27,2106 51545 DLOAD ABS # CHECK TO SEE IF WE ARE POINTING
020419,000445: 27,2107 03765 SCAXIS # THE THRUST AXIS
020420,000446: 27,2110 51025 DSU BPL
020421,000447: 27,2111 14404 SINVEC1 # SIN 49.4 DEGS
020422,000448: 27,2112 56160 FINDGIMB # IF SO, WE ARE TRYING TO POINT IT INTO
020423,000449: 27,2113 77775 VLOAD # GIMBAL LOCK, ABORT COULD GO HERE
020424,000450: 27,2114 77626 STADR
020425,000451: 27,2115 50515 STOVL MIS +12D
020426,000452: 27,2116 77626 STADR # STORE MFS (IN PD LIST) IN MIS
020427,000453: 27,2117 50523 STOVL MIS +6
020428,000454: 27,2120 77626 STADR
020429,000455: 27,2121 50531 STOVL MIS
020430,000456: 27,2122 03254 MIS +6 # INNER GIMBAL AXIS IN FINAL S/C AXES
020431,000457: 27,2123 57444 BPL VCOMP # LOCATE THE IG AXIS DIRECTION CLOSEST TO
020432,000458: 27,2124 56125 IGSAMEX # FINAL X S/C AXIS
020433,000459:
020434,000460: 27,2125 50035 IGSAMEX VXV BMN # FIND THE SHORTEST WAY OF ROTATING THE
020435,000461: 27,2126 03765 SCAXIS # S/C OUT OF GIMBAL LOCK BY A ROTATION
020436,000462: 27,2127 56134 U=SCAXIS # ABOUT +- SCAXIS, I.E., IF (IG (SGN MFS3)
020437,000463: # X SCAXIS . XF) LESS THAN Q, U = SCAXIS
020438,000464: # OTHERWISE U = -SCAXIS.
020439,000465:
020440,000466: 27,2130 57575 VLOAD VCOMP
020441,000467: 27,2131 03765 SCAXIS
020442,000468: 27,2132 37270 STCALL COF # ROTATE ABOUT -SCAXIS
020443,000469: 27,2133 56137 CHEKAXIS
020444,000470: 27,2134 77775 U=SCAXIS VLOAD
020445,000471: 27,2135 03765 SCAXIS
020446,000472: 27,2136 03270 STORE COF # ROTATE ABOUT + SCAXIS
020447,000473: 27,2137 51545 CHEKAXIS DLOAD ABS
020448,000474: 27,2140 03765 SCAXIS # SEE IF WE ARE POINTING THE AOT
020449,000475: 27,2141 51025 DSU BPL
020450,000476: 27,2142 14406 SINVEC2 # SIN 29.5 DEGS
020451,000477: 27,2143 56147 PICKANG1 # IF SO, ROTATE 50 DEGS ABOUT +- SCAXIS
020452,000478: 27,2144 52145 DLOAD GOTO # IF NOT, MUST BE POINTING THE TRANSPONDER
020453,000479: 27,2145 14412 VECANG2 # OR SOME VECTOR IN THE Y, OR Z PLANE
020454,000480: 27,2146 56151 COMPMFSN # IN THIS CASE ROTATE 35 DEGS TO GET OUT
020455,000481: # OF GIMBAL LOCK (VECANG2 garbled)
020456,000482: 27,2147 77745 PICKANG1 DLOAD
020457,000483: 27,2150 14410 VECANG1 # =.50 DEGS.
020458,000484: 27,2151 77624 COMPMFSN CALL
020459,000485: 27,2152 44527 DELCOMP # COMPUTE THE ROTATION ABOUT SCAXIS TO
020460,000486: 27,2153 75160 AXC,1 AXC,2 # BRING MFS OUT OF GIMBAL LOCK
020461,000487: 27,2154 03245 MIS
020462,000488: 27,2155 02230 KEL
020463,000489: 27,2156 77624 CALL # COMPUTE THE NEW TRANSFORMATION FROM
020464,000490: 27,2157 44312 MXM3 # DESIRED S/C AXES TO STABLE MEMBER AXES
020465,000491: # WHICH WILL ALIGN VI WITH VF AND AVOID
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Page 492 |
020467,000493: # GIMBAL LOCK
020468,000494: 27,2160 45160 FINDGIMB AXC,1 CALL
020469,000495: 27,2161 00000 0 # EXTRACT THE COMMANDED CDU ANGLES FROM
020470,000496: 27,2162 44654 DCMTOCDU # THIS MATRIX
020471,000497: 27,2163 40234 RTB SETPD
020472,000498: 27,2164 21621 V1STO2S # CONVERT TO 2'S COMPLEMENT
020473,000499: 27,2165 00001 0
020474,000500: 27,2166 77650 GOTO
020475,000501: 27,2167 03324 VECQTEMP # RETURN TO CALLER
020476,000502:
020477,000503: 27,2170 50375 PICKAXIS VLOAD DOT # IF VF X VI = 0, FIND VF, VI
020478,000504: 27,2171 00035 28D
020479,000505: 27,2172 03765 SCAXIS
020480,000506: 27,2173 72240 BMN TLOAD
020481,000507: 27,2174 54354 ROT180
020482,000508: 27,2175 00032 25D
020483,000509: 27,2176 77650 GOTO # IF VF = VI, CDU DESIRED = PRESENT CDU
020484,000510: 27,2177 03324 VECQTEMP # PRESETN CDU ANGLES
020485,000511:
020486,000512: 35,2000 BANK 35
020487,000513: 26,2000 SETLOC MANUVER1
020488,000514: 26,2000 BANK
020489,000515: 26,2354 47375 ROT180 VLOAD VXV # IF VF, VI ANTI-PARALLEL, 180 DEG ROTATION
020490,000516: 26,2355 03254 MIS +6 # IS REQUIRED. Y STABLE MEMBER AXIS IN
020491,000517: 26,2356 06522 HIDPHALF # INITIAL S/C AXES.
020492,000518: 26,2357 47256 UNIT VXV # FIND Y(SM) X X(I)
020493,000519: 26,2360 03765 SCAXIS # FIND UNIT(VI X UNIT(Y(SM) X X(I)))
020494,000520: 26,2361 40056 UNIT BOV # I.E., PICK A VECTOR IN THE PLANE OF X(I),
020495,000521: 26,2362 54376 PICKX # Y(SM) PERPENDICULAR TO VI
020496,000522: 26,2363 17270 STODL COF
020497,000523: 26,2364 00045 36D # CHECK MAGNITUDE
020498,000524: 26,2365 50025 DSU BMN # OF THIS VECTOR.
020499,000525: 26,2366 14415 DPB-14 # IF LESS THAN B-14,
020500,000526: 26,2367 54376 PICKX # PICK X-AXIS.
020501,000527: 26,2370 77775 VLOAD
020502,000528: 26,2371 03270 COF
020503,000529: 26,2372 17270 XROT STODL COF
020504,000530: 26,2373 06522 HIDPHALF
020505,000531: 26,2374 77650 GOTO
020506,000532: 26,2375 56072 COMPMATX
020507,000533: 26,2376 52175 PICKX VLOAD GOTO # PICK THE XAXIS IN THIS CASE
020508,000534: 26,2377 06522 HIDPHALF
020509,000535: 26,2400 54372 XROT
020510,000536: 26,2401 15555 35172 SINGIMLC 2DEC .4285836003 # = SIN(59)
020511,000537: 26,2403 14113 36326 SINVEC1 2DEC .3796356537 # = SIN(49.4)
020512,000538: 26,2405 07701 35703 SINVEC2 2DEC .2462117800 # = SIN(29.5)
020513,000539: 26,2407 04343 21616 VECANG1 2DEC .1388888889 # = 50 DEGREES
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Page 493 |
020515,000541: 26,2411 03070 34344 VECANG2 2DEC .09722222222 # = 35 DEGREES
020516,000542:
020517,000543: 26,2413 00000 1BITDP OCT 0 # KEEP THIS BEFORE DPB(-14)
020518,000544: 26,2414 00001 DPB-14 OCT 00001
020519,000545: 26,2415 00000 OCT 00000
020520,000546:
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Page 494 |
020522,000548: # ROUTINE FOR INITIATING AUTOMATIC MANEUVER VIA KEYBOARD (V49)
020523,000549:
020524,000550: 34,2000 BANK 34
020525,000551: 23,2000 SETLOC R62
020526,000552: 23,2000 BANK
020527,000553: 23,2103 E6,1675 EBANK= BCDU
020528,000554:
020529,000555: 23,2103 COUNT* $$/R62
020530,000556:
020531,000557: 23,2103 23,2103 R62DISP EQUALS R62FLASH
020532,000558:
020533,000559: 23,2103 35010 R62FLASH CAF V06N22 # FLASH V06N22 AND
020534,000560: 23,2104 04616 TC BANKCALL # ICDU ANGLES
020535,000561: 23,2105 20477 CADR GOFLASH
020536,000562: 23,2106 15472 TCF ENDEXT # TERMINATE
020537,000563: 23,2107 12111 TCF GOMOVE # PROCEED
020538,000564: 23,2110 12103 TCF R62FLASH # ENTER
020539,000565:
020540,000566: # ASTRONAUT MAY LOAD NEW ICDUS AT THIS
020541,000567: # POINT.
020542,000568: 23,2111 05504 GOMOVE TC UPFLAG # SET FOR 3-AXIS MANEUVER
020543,000569: 23,2112 00124 ADRES 3AXISFLG
020544,000570:
020545,000571: 23,2113 04616 TC BANKCALL
020546,000572: 23,2114 54123 CADR R60LEM
020547,000573: 23,2115 15472 TCF ENDEXT # END R62
020548,000574:
End of include-file R60_62.agc. Parent file is MAIN.agc