Source Code
053116,000001: # Copyright: Public domain.
053117,000002: # Filename: INFLIGHT_ALIGNMENT_ROUTINES.agc
053118,000003: # Purpose: Part of the source code for Luminary 1A build 099.
053119,000004: # It is part of the source code for the Lunar Module's (LM)
053120,000005: # Apollo Guidance Computer (AGC), for Apollo 11.
053121,000006: # Assembler: yaYUL
053122,000007: # Contact: Ron Burkey <info@sandroid.org>.
053123,000008: # Website: www.ibiblio.org/apollo.
053124,000009: # Pages: 1249-1258
053125,000010: # Mod history: 2009-05-26 RSB Adapted from the corresponding
053126,000011: # Luminary131 file, using page
053127,000012: # images from Luminary 1A.
053128,000013:
053129,000014: # This source code has been transcribed or otherwise adapted from
053130,000015: # digitized images of a hardcopy from the MIT Museum. The digitization
053131,000016: # was performed by Paul Fjeld, and arranged for by Deborah Douglas of
053132,000017: # the Museum. Many thanks to both. The images (with suitable reduction
053133,000018: # in storage size and consequent reduction in image quality as well) are
053134,000019: # available online at www.ibiblio.org/apollo. If for some reason you
053135,000020: # find that the images are illegible, contact me at info@sandroid.org
053136,000021: # about getting access to the (much) higher-quality images which Paul
053137,000022: # actually created.
053138,000023:
053139,000024: # Notations on the hardcopy document read, in part:
053140,000025:
053141,000026: # Assemble revision 001 of AGC program LMY99 by NASA 2021112-61
053142,000027: # 16:27 JULY 14, 1969
053143,000028:
053144,000029: # Page 1249
053145,000030: 22,3773 BANK 22
053146,000031: 23,2000 SETLOC INFLIGHT
053147,000032: 23,2000 BANK
053148,000033:
053149,000034: 23,3247 E5,1642 EBANK= XSM
053150,000035:
053151,000036: # CALCGTA COMPUTES THE GYRO TORQUE ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
053152,000037:
053153,000038: # THE INPUT IS THE DESIRED STABLE MEMBER COORDINATES REFERRED TO PRESENT STABLE MEMBER COORDINATES. THE THREE
053154,000039: # HALF-UNIT VECTORS ARE STORED AT XDC, YDC, AND ZDC.
053155,000040:
053156,000041: # THE OUTPUTS ARE THE THREE GYRO TORQUE ANGLES TO BE APPLIED TO THE Y, Z, AND X GYROS AND ARE STORED DP AT IGC,
053157,000042: # MGC, AND OGC RESPECTIVELY.
053158,000043:
053159,000044: 23,3247 COUNT* $$/INFLT
053160,000045: 23,3247 71220 CALCGTA ITA DLOAD # PUSHDOWN 00-03, 16D-27D, 34D-37D
053161,000046: 23,3250 00051 S2 # XDC = (XD1 XD2 XD3)
053162,000047: 23,3251 02665 XDC # YDC = (YD1 YD2 YD3)
053163,000048: 23,3252 65325 PDDL PDDL # ZDC = (ZD1 ZD2 ZD3)
053164,000049: 23,3253 06522 HI6ZEROS
053165,000050: 23,3254 02671 XDC +4
053166,000051: 23,3255 55476 DCOMP VDEF
053167,000052: 23,3256 77656 UNIT
053168,000053: 23,3257 14027 STODL ZPRIME # ZP = UNIT(-XD3 0 XD1) = (ZP1 ZP2 ZP3)
053169,000054: 23,3260 00027 ZPRIME
053170,000055:
053171,000056: 23,3261 77742 SR1
053172,000057: 23,3262 14023 STODL SINTH # SIN(IGC) = ZP1
053173,000058: 23,3263 00033 ZPRIME +4
053174,000059: 23,3264 77742 SR1
053175,000060: 23,3265 34021 STCALL COSTH # COS(IGC) = ZP3
053176,000061: 23,3266 47320 ARCTRIG
053177,000062:
053178,000063: 23,3267 16742 STODL IGC # Y GYRO TORQUING ANGLE FRACTION OF REV.
053179,000064: 23,3270 02667 XDC +2
053180,000065: 23,3271 77742 SR1
053181,000066: 23,3272 14023 STODL SINTH # SIN(MGC) = XD2
053182,000067: 23,3273 00027 ZPRIME
053183,000068:
053184,000069: 23,3274 65205 DMP PDDL
053185,000070: 23,3275 02671 XDC +4 # PD00 = (ZP1)(XD3)
053186,000071: 23,3276 00033 ZPRIME +4
053187,000072:
053188,000073: 23,3277 45205 DMP DSU
053189,000074: 23,3300 02665 XDC # MPAC = (ZP3)(XD1)
053190,000075: 23,3301 77626 STADR
053191,000076: 23,3302 43756 STCALL COSTH # COS(MGC) = MPAC - PD00
053192,000077: 23,3303 47320 ARCTRIG
053193,000078: # Page 1250
053194,000079: 23,3304 26744 STOVL MGC # Z GYRO TORQUING ANGLE FRACTION OF REV.
053195,000080: 23,3305 00027 ZPRIME
053196,000081: 23,3306 77641 DOT
053197,000082: 23,3307 02701 ZDC
053198,000083: 23,3310 24021 STOVL COSTH # COS(OGC) = ZP . ZDC
053199,000084: 23,3311 00027 ZPRIME
053200,000085: 23,3312 77641 DOT
053201,000086: 23,3313 02673 YDC
053202,000087: 23,3314 34023 STCALL SINTH # SIN(OGC) = ZP . YDC
053203,000088: 23,3315 47320 ARCTRIG
053204,000089:
053205,000090: 23,3316 36740 STCALL OGC # X GYRO TORQUING ANGLE FRACTION OF REV.
053206,000091: 23,3317 00051 S2
053207,000092:
053208,000093: # Page 1251
053209,000094: # ARCTRIG COMPUTES AN ANGLE GIVEN THE SINE AND COSINE OF THIS ANGLE.
053210,000095:
053211,000096: # THE INPUTS ARE SIN/4 AND COS/4 STORED UP AT SINTH AND COSTH.
053212,000097:
053213,000098: # THE OUTPUT IS THE CALCULATED ANGLE BETWEEN +.5 AND -.5 REVOLUTIONS AND STORED AT THETA. THE OUTPUT IS ALSO
053214,000099: # AVAILABLE AT MPAC.
053215,000100:
053216,000101: 23,3320 51545 ARCTRIG DLOAD ABS # PUSHDOWN 16D-21D
053217,000102: 23,3321 00023 SINTH
053218,000103: 23,3322 50025 DSU BMN
053219,000104: 23,3323 07534 QTSN45 # ABS(SIN/4) - SIN(45)/4
053220,000105: 23,3324 47333 TRIG1 # IF (-45,45) OR (135,-135)
053221,000106:
053222,000107: 23,3325 72545 DLOAD SL1 # (45,135) OR (-135,-45)
053223,000108: 23,3326 00021 COSTH
053224,000109: 23,3327 75326 ACOS SIGN
053225,000110: 23,3330 00023 SINTH
053226,000111: 23,3331 00025 STORE THETA # X = ARCCOS(COS) WITH SIGN(SIN)
053227,000112: 23,3332 77616 RVQ
053228,000113:
053229,000114: 23,3333 72545 TRIG1 DLOAD SL1 # (-45,45) OR (135,-135)
053230,000115: 23,3334 00023 SINTH
053231,000116: 23,3335 77736 ASIN
053232,000117: 23,3336 14025 STODL THETA # X = ARCSIN(SIN) WITH SIGN(SIN)
053233,000118: 23,3337 00021 COSTH
053234,000119: 23,3340 77640 BMN
053235,000120: 23,3341 47344 TRIG2 # IF (135,-135)
053236,000121:
053237,000122: 23,3342 43545 DLOAD RVQ
053238,000123: 23,3343 00025 THETA # X = ARCSIN(SIN) (-45,45)
053239,000124:
053240,000125: 23,3344 75345 TRIG2 DLOAD SIGN # (135,-135)
053241,000126: 23,3345 06520 HIDPHALF
053242,000127: 23,3346 00023 SINTH
053243,000128: 23,3347 77625 DSU
053244,000129: 23,3350 00025 THETA
053245,000130: 23,3351 00025 STORE THETA # X = .5 WITH SIGN(SIN) - ARCSIN(SIN)
053246,000131: 23,3352 77616 RVQ # (+) - (+) OR (-) - (-)
053247,000132:
053248,000133: # Page 1252
053249,000134: # SMNB, NBSM, AND AXISROT, WHICH USED TO APPEAR HERE, HAVE BEEN
053250,000135: # COMBINED IN A ROUTINE CALLED AX*SR*T, WHICH APPEARS AMONG THE POWERED
053251,000136: # FLIGHT SUBROUTINES.
053252,000137:
053253,000138: # Page 1253
053254,000139: # CALCGA COMPUTES THE CDU DRIVING ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
053255,000140:
053256,000141: # THE INPUTS ARE 1) THE NAVIGATION BASE COORDINATES REFERRED TO ANY COORDINATE SYSTEM. THE THREE HALF-UNIT
053257,000142: # VECTORS ARE STORED AT XNB, YNB, AND ZNB. 2) THE DESIRED STABLE MEMBER COORDINATES REFERRED TO THE SAME
053258,000143: # COORDINATE SYSTEM ARE STORED AT XSM, YSM, AND ZSM.
053259,000144:
053260,000145: # THE OUTPUTS ARE THE THREE CDU DRIVING ANGLES AND ARE STORED SP AT THETAD, THETAD +1, AND THETAD +2.
053261,000146:
053262,000147: 23,3353 77601 CALCGA SETPD # PUSHDOWN 00-05, 16D-21D, 34D-37D
053263,000148: 23,3354 00001 0
053264,000149: 23,3355 47375 VLOAD VXV
053265,000150: 23,3356 02665 XNB # XNB = OGA (OUTER GIMBAL AXIS)
053266,000151: 23,3357 02651 YSM # YSM = IGA (INNER GIMBAL AXIS)
053267,000152: 23,3360 41456 UNIT PUSH # PD0 = UNIT(OGA X IGA) = MGA
053268,000153:
053269,000154: 23,3361 44041 DOT ITA
053270,000155: 23,3362 02701 ZNB
053271,000156: 23,3363 00051 S2
053272,000157: 23,3364 24021 STOVL COSTH # COS(OG) = MGA . ZNB
053273,000158: 23,3365 00001 0
053274,000159: 23,3366 77641 DOT
053275,000160: 23,3367 02673 YNB
053276,000161: 23,3370 34023 STCALL SINTH # SIN(OG) = MGA . YNB
053277,000162: 23,3371 47320 ARCTRIG
053278,000163: 23,3372 26740 STOVL OGC
053279,000164: 23,3373 00001 0
053280,000165:
053281,000166: 23,3374 50235 VXV DOT # PROVISION FOR MG ANGLE OF 90 DEGREES
053282,000167: 23,3375 02665 XNB
053283,000168: 23,3376 02651 YSM
053284,000169: 23,3377 77752 SL1
053285,000170: 23,3400 24021 STOVL COSTH # COS(MG) = IGA . (MGA X OGA)
053286,000171: 23,3401 02651 YSM
053287,000172: 23,3402 77641 DOT
053288,000173: 23,3403 02665 XNB
053289,000174: 23,3404 34023 STCALL SINTH # SIN(MG) = IGA . OGA
053290,000175: 23,3405 47320 ARCTRIG
053291,000176: 23,3406 02744 STORE MGC
053292,000177:
053293,000178: 23,3407 45246 ABS DSU
053294,000179: 23,3410 07536 .166...
053295,000180: 23,3411 77644 BPL
053296,000181: 23,3412 47431 GIMLOCK1 # IF ANGLE GREATER THAN 60 DEGREES
053297,000182:
053298,000183: 23,3413 50375 CALCGA1 VLOAD DOT
053299,000184: 23,3414 02657 ZSM
053300,000185: 23,3415 00001 0
053301,000186: 23,3416 24021 STOVL COSTH # COS(IG) = ZSM . MGA
053302,000187: 23,3417 02643 XSM
053303,000188: # Page 1254
053304,000189: 23,3420 45441 DOT STADR
053305,000190: 23,3421 43754 STCALL SINTH # SIN(IG) = XSM . MGA
053306,000191: 23,3422 47320 ARCTRIG
053307,000192:
053308,000193: 23,3423 26742 STOVL IGC
053309,000194: 23,3424 02740 OGC
053310,000195: 23,3425 77634 RTB
053311,000196: 23,3426 21620 V1STO2S
053312,000197: 23,3427 34322 STCALL THETAD
053313,000198: 23,3430 00051 S2
053314,000199:
053315,000200: 23,3431 77776 GIMLOCK1 EXIT
053316,000201: 23,3432 05567 TC ALARM
053317,000202: 23,3433 00401 OCT 00401
053318,000203: 23,3434 05504 TC UPFLAG # GIMBAL LOCK HAS OCCURRED
053319,000204: 23,3435 00056 ADRES GLOKFAIL
053320,000205:
053321,000206: 23,3436 06037 TC INTPRET
053322,000207: 23,3437 77650 GOTO
053323,000208: 23,3440 47413 CALCGA1
053324,000209:
053325,000210: # Page 1255
053326,000211: # AXISGEN COMPUTES THE COORDINATES OF ONE COORDINATE SYSTEM REFERRED TO ANOTHER COORDINATE SYSTEM.
053327,000212:
053328,000213: # THE INPUTS ARE 1) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM A STORED AT STARAD. 2) THE STAR2 VECTOR
053329,000214: # REFERRED TO COORDINATE SYSTEM A STORED AT STARAD +6. 3) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM B STORED
053330,000215: # AT LOCATION 6 OF THE VAC AREA. 4) THE STAR2 VECTOR REFERRED TO COORDINATE SYSTEM B STORED AT LOCATION 12D OF
053331,000216: # THE VAC AREA.
053332,000217:
053333,000218: # THE OUTPUT DEFINES COORDINATE SYSTEM A REFERRED TO COORDINATE SYSTEM B. THE THREE HALF-UNIT VECTORS ARE STORED
053334,000219: # AT LOCATIONS XDC, XDC +6, XDC +12D, AND STARAD, STARAD +6, STARAD +12D.
053335,000220:
053336,000221: 23,3441 66370 AXISGEN AXT,1 SSP # PUSHDOWN 00-30D, 34D-37D
053337,000222: 23,3442 02714 STARAD +6
053338,000223: 23,3443 00051 S1
053339,000224: 23,3444 02700 STARAD -6
053340,000225:
053341,000226: 23,3445 77601 SETPD
053342,000227: 23,3446 00001 0
053343,000228: 23,3447 46773 AXISGEN1 VLOAD* VXV* # 06D UA = S1
053344,000229: 23,3450 02723 STARAD +12D,1 # STARAD +00D UB = S1
053345,000230: 23,3451 02731 STARAD +18D,1
053346,000231: 23,3452 77656 UNIT # 12D VA = UNIT(S1 X S2)
053347,000232: 23,3453 06731 STORE STARAD +18D,1 # STARAD +06D VB = UNIT(S1 X S2)
053348,000233: 23,3454 77773 VLOAD*
053349,000234: 23,3455 02723 STARAD +12D,1
053350,000235:
053351,000236: 23,3456 76433 VXV* VSL1
053352,000237: 23,3457 02731 STARAD +18D,1 # 18D WA = UA X VA
053353,000238: 23,3460 06737 STORE STARAD +24D,1 # STARAD +12D WB = UB X VB
053354,000239:
053355,000240: 23,3461 77700 TIX,1
053356,000241: 23,3462 47447 AXISGEN1
053357,000242:
053358,000243: 23,3463 66160 AXC,1 SXA,1
053359,000244: 23,3464 00006 6
053360,000245: 23,3465 00036 30D
053361,000246:
053362,000247: 23,3466 66370 AXT,1 SSP
053363,000248: 23,3467 00022 18D
053364,000249: 23,3470 00051 S1
053365,000250: 23,3471 00006 6
053366,000251:
053367,000252: 23,3472 66374 AXT,2 SSP
053368,000253: 23,3473 00006 6
053369,000254: 23,3474 00052 S2
053370,000255: 23,3475 00002 2
053371,000256:
053372,000257: 23,3476 76720 AXISGEN2 XCHX,1 VLOAD*
053373,000258: 23,3477 00036 30D # X1=-6 X2=+6 X1=-6 X2=+4 X1=-6 X2=+2
053374,000259: 23,3500 00001 0,1
053375,000260:
053376,000261: # Page 1256
053377,000262: 23,3501 62757 VXSC* PDVL* # J=(UA)(UB1) J=(UA)(UB2) J=(UA)(UB3)
053378,000263: 23,3502 75062 STARAD +6,2
053379,000264: 23,3503 00007 6,1
053380,000265: 23,3504 77757 VXSC*
053381,000266: 23,3505 75054 STARAD +12D,2
053382,000267: 23,3506 30031 STOVL* 24D # K=(VA)(VB1) J=(VA)(VB2) J=(VA)(VB3)
053383,000268: 23,3507 00015 12D,1
053384,000269:
053385,000270: 23,3510 53357 VXSC* VAD
053386,000271: 23,3511 75046 STARAD +18D,2 # L=(WA)(WB1) J=(WA)(WB2) J=(WA)(WB3)
053387,000272: 23,3512 76455 VAD VSL1
053388,000273: 23,3513 00031 24D
053389,000274: 23,3514 53520 XCHX,1 UNIT
053390,000275: 23,3515 00036 30D
053391,000276: 23,3516 06707 STORE XDC +18D,1 # XDC = L+J+K YDC = L+J+K ZDC = L+J+K
053392,000277:
053393,000278: 23,3517 77700 TIX,1
053394,000279: 23,3520 47521 AXISGEN3
053395,000280:
053396,000281: 23,3521 77704 AXISGEN3 TIX,2
053397,000282: 23,3522 47476 AXISGEN2
053398,000283:
053399,000284: 23,3523 77775 VLOAD
053400,000285: 23,3524 02665 XDC
053401,000286: 23,3525 26707 STOVL STARAD
053402,000287: 23,3526 02673 YDC
053403,000288: 23,3527 26715 STOVL STARAD +6
053404,000289: 23,3530 02701 ZDC
053405,000290: 23,3531 02723 STORE STARAD +12D
053406,000291:
053407,000292: 23,3532 77616 RVQ
053408,000293:
053409,000294: # Page 1257
053410,000295: 23,3533 05520 26075 QTSN45 2DEC .1768
053411,000296:
053412,000297: 23,3535 05252 25253 .166... 2DEC .1666666667
053413,000298:
053414,000299: # Page 1258 (empty page)
053415,000300:
End of include-file INFLIGHT_ALIGNMENT_ROUTINES.agc. Parent file is MAIN.agc