Source Code

058636,000001: # Copyright: Public domain. 058637,000002: # Filename: INFLIGHT_ALIGNMENT_ROUTINES.agc 058638,000003: # Purpose: Part of the source code for Colossus 2A, AKA Comanche 055. 058639,000004: # It is part of the source code for the Command Module's (CM) 058640,000005: # Apollo Guidance Computer (AGC), for Apollo 11. 058641,000006: # Assembler: yaYUL 058642,000007: # Contact: Ron Burkey <info@sandroid.org>. 058643,000008: # Website: www.ibiblio.org/apollo. 058644,000009: # Pages: 1355-1364 058645,000010: # Mod history: 2009-05-14 RSB Adapted from the Colossus249/ file of the 058646,000011: # same name, using Comanche055 page images. 058647,000012: 058648,000013: # This source code has been transcribed or otherwise adapted from digitized 058649,000014: # images of a hardcopy from the MIT Museum. The digitization was performed 058650,000015: # by Paul Fjeld, and arranged for by Deborah Douglas of the Museum. Many 058651,000016: # thanks to both. The images (with suitable reduction in storage size and 058652,000017: # consequent reduction in image quality as well) are available online at 058653,000018: # www.ibiblio.org/apollo. If for some reason you find that the images are 058654,000019: # illegible, contact me at info@sandroid.org about getting access to the 058655,000020: # (much) higher-quality images which Paul actually created. 058656,000021: 058657,000022: # Notations on the hardcopy document read, in part: 058658,000023: 058659,000024: # Assemble revision 055 of AGC program Comanche by NASA 058660,000025: # 2021113-051. 10:28 APR. 1, 1969 058661,000026: 058662,000027: # This AGC program shall also be referred to as 058663,000028: # Colossus 2A 058664,000029: 058665,000030: # Page 1355 058666,000031: 22,3510 BANK 22 058667,000032: 23,2000 SETLOC INFLIGHT 058668,000033: 23,2000 BANK 058669,000034: 058670,000035: 23,3205 0002671 EBANK= XSM 058671,000036: 058672,000037: # CALCGTA COMPUTES THE GYRO TORQUE ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION. 058673,000038: 058674,000039: # THE INPUT IS THE DESIRED STABLE MEMBER COORDINATES REFERRED TO PRESENT STABLE MEMBER COORDINATES. THE THREE 058675,000040: # HALF-UNIT VECTORS ARE STORED AT XDC, YDC, AND ZDC. 058676,000041: 058677,000042: # THE OUTPUTS ARE THE THREE GYRO TORQUE ANGLES TO BE APPLIED TO THE Y, Z, AND X GYROS AND ARE STORED DP AT IGC, 058678,000043: # MGC, AND OGC RESPECTIVELY. 058679,000044: 058680,000045: 23,3205 COUNT 23/INFLT 058681,000046: 058682,000047: 23,3205 71220 CALCGTA ITA DLOAD # PUSHDOWN 00-03, 16D-27D, 34D-37D 058683,000048: 23,3206 00051 S2 # XDC = (XD1 XD2 XD3) 058684,000049: 23,3207 02714 XDC # YDC = (YD1 YD2 YD3) 058685,000050: 23,3210 65325 PDDL PDDL # ZDC = (ZD1 ZD2 ZD3) 058686,000051: 23,3211 15335 HI6ZEROS 058687,000052: 23,3212 02720 XDC +4 058688,000053: 23,3213 55476 DCOMP VDEF 058689,000054: 23,3214 77656 UNIT 058690,000055: 23,3215 14027 STODL ZPRIME # ZP = UNIT(-XD3 0 XD1) = (ZP1 ZP2 ZP3) 058691,000056: 23,3216 00027 ZPRIME 058692,000057: 058693,000058: 23,3217 77742 SR1 058694,000059: 23,3220 14023 STODL SINTH # SIN(IGC) = ZP1 058695,000060: 23,3221 00033 ZPRIME +4 058696,000061: 23,3222 77742 SR1 058697,000062: 23,3223 34021 STCALL COSTH # COS(IGC) = ZP3 058698,000063: 23,3224 47256 ARCTRIG 058699,000064: 058700,000065: 23,3225 16762 STODL IGC # Y GYRO TORQUING ANGLE FRACTION OF REV. 058701,000066: 23,3226 02716 XDC +2 058702,000067: 23,3227 77742 SR1 058703,000068: 23,3230 14023 STODL SINTH # SIN(MGC) = XD2 058704,000069: 23,3231 00027 ZPRIME 058705,000070: 058706,000071: 23,3232 65205 DMP PDDL 058707,000072: 23,3233 02720 XDC +4 # PD00 = (ZP1)(XD3) 058708,000073: 23,3234 00033 ZPRIME +4 058709,000074: 058710,000075: 23,3235 45205 DMP DSU 058711,000076: 23,3236 02714 XDC # MPAC = (ZP3)(XD1) 058712,000077: 23,3237 77626 STADR 058713,000078: 23,3240 43756 STCALL COSTH # COS(MGC) = MPAC - PD00 058714,000079: 23,3241 47256 ARCTRIG 058715,000080: # Page 1356 058716,000081: 23,3242 26764 STOVL MGC # Z GYRO TORQUING ANGLE FRACTION OF REV. 058717,000082: 23,3243 00027 ZPRIME 058718,000083: 23,3244 77641 DOT 058719,000084: 23,3245 02730 ZDC 058720,000085: 23,3246 24021 STOVL COSTH # COS(OGC) = ZP . ZDC 058721,000086: 23,3247 00027 ZPRIME 058722,000087: 23,3250 77641 DOT 058723,000088: 23,3251 02722 YDC 058724,000089: 23,3252 34023 STCALL SINTH # SIN(OGC) = ZP . YDC 058725,000090: 23,3253 47256 ARCTRIG 058726,000091: 058727,000092: 23,3254 36760 STCALL OGC # X GYRO TORQUING ANGLE FRACTION OF REV. 058728,000093: 23,3255 00051 S2 058729,000094: 058730,000095: # Page 1357 058731,000096: # ARCTRIG COMPUTES AN ANGLE GIVEN THE SINE AND COSINE OF THIS ANGLE. 058732,000097: 058733,000098: # THE INPUTS ARE SIN/4 AND COS/4 STORED DP AT SINTH AND COSTH. 058734,000099: 058735,000100: # THE OUTPUT IS THE CALCULATED ANGLE BETWEEN +.5 AND -.5 REVOLUTIONS AND STORED AT THETA. THE OUTPUT IS ALSO 058736,000101: # AVAILABLE AT MPAC. 058737,000102: 058738,000103: 23,3256 51545 ARCTRIG DLOAD ABS # PUSHDOWN 16D-21D 058739,000104: 23,3257 00023 SINTH 058740,000105: 23,3260 50025 DSU BMN 058741,000106: 23,3261 07474 QTSN45 # ABS(SIN/4) - SIN(45)/4 058742,000107: 23,3262 47271 TRIG1 # IF (-45,45) OR (135,-135) 058743,000108: 058744,000109: 23,3263 72545 DLOAD SL1 # (45,135) OR (-135,-45) 058745,000110: 23,3264 00021 COSTH 058746,000111: 23,3265 75326 ACOS SIGN 058747,000112: 23,3266 00023 SINTH 058748,000113: 23,3267 00025 STORE THETA # X = ARCCOS(COS) WITH SIGN(SIN) 058749,000114: 23,3270 77616 RVQ 058750,000115: 058751,000116: 23,3271 72545 TRIG1 DLOAD SL1 # (-45,45) OR (135,-135) 058752,000117: 23,3272 00023 SINTH 058753,000118: 23,3273 77736 ASIN 058754,000119: 23,3274 14025 STODL THETA # X = ARCSIN(SIN) WITH SIGN(SIN) 058755,000120: 23,3275 00021 COSTH 058756,000121: 23,3276 77640 BMN 058757,000122: 23,3277 47302 TRIG2 # IF (135,-135) 058758,000123: 058759,000124: 23,3300 43545 DLOAD RVQ 058760,000125: 23,3301 00025 THETA # X = ARCSIN(SIN) (-45,45) 058761,000126: 058762,000127: 23,3302 75345 TRIG2 DLOAD SIGN # (135,-135) 058763,000128: 23,3303 15333 HIDPHALF 058764,000129: 23,3304 00023 SINTH 058765,000130: 23,3305 77625 DSU 058766,000131: 23,3306 00025 THETA 058767,000132: 23,3307 00025 STORE THETA # X = .5 WITH SIGN(SIN) - ARCSIN(SIN) 058768,000133: 23,3310 77616 RVQ # (+) - (+) OR (-) - (-) 058769,000134: 058770,000135: # Page 1358 058771,000136: # SMNB, NBSM, AND AXISROT, WHICH USED TO APPEAR HERE, HAVE BEEN 058772,000137: # COMBINED IN A ROUTINE CALLED AX*SR*T, WHICH APPEARS AMONG THE POWERED 058773,000138: # FLIGHT SUBROUTINES. 058774,000139: 058775,000140: # Page 1359 058776,000141: # CALCGA COMPUTES THE CDU DRIVING ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION. 058777,000142: 058778,000143: # THE INPUTS ARE 1) THE NAVIGATION BASE COORDINATES REFERRED TO ANY COORDINATE SYSTEM. THE THREE HALF-UNIT 058779,000144: # VECTORS ARE STORED AT XNB, YNB, AND ZNB. 2) THE DESIRED STABLE MEMBER COORDINATES REFERRED TO THE SAME 058780,000145: # COORDINATE SYSTEM ARE STORED AT XSM, YSM, AND ZSM. 058781,000146: 058782,000147: # THE OUTPUTS ARE THE THREE CDU DRIVING ANGLES AND ARE STORED SP AT THETAD, THETAD +1, AND THETAD +2. 058783,000148: 058784,000149: 23,3311 77601 CALCGA SETPD # PUSHDOWN 00-05, 16D-21D, 34D-37D 058785,000150: 23,3312 00001 0 058786,000151: 23,3313 47375 VLOAD VXV 058787,000152: 23,3314 02714 XNB # XNB = OGA (OUTER GIMBAL AXIS) 058788,000153: 23,3315 02700 YSM # YSM = IGA (INNER GIMBAL AXIS) 058789,000154: 23,3316 41456 UNIT PUSH # PD0 = UNIT(OGA X IGA) = MGA 058790,000155: 058791,000156: 23,3317 44041 DOT ITA 058792,000157: 23,3320 02730 ZNB 058793,000158: 23,3321 00051 S2 058794,000159: 23,3322 24021 STOVL COSTH # COS(OG) = MGA . ZNB 058795,000160: 23,3323 00001 0 058796,000161: 23,3324 77641 DOT 058797,000162: 23,3325 02722 YNB 058798,000163: 23,3326 34023 STCALL SINTH # SIN(OG) = MGA . YNB 058799,000164: 23,3327 47256 ARCTRIG 058800,000165: 23,3330 26760 STOVL OGC 058801,000166: 23,3331 00001 0 058802,000167: 058803,000168: 23,3332 50235 VXV DOT # PROVISION FOR MG ANGLE OF 90 DEGREES 058804,000169: 23,3333 02714 XNB 058805,000170: 23,3334 02700 YSM 058806,000171: 23,3335 77752 SL1 058807,000172: 23,3336 24021 STOVL COSTH # COS(MG) = IGA . (MGA X OGA) 058808,000173: 23,3337 02700 YSM 058809,000174: 23,3340 77641 DOT 058810,000175: 23,3341 02714 XNB 058811,000176: 23,3342 34023 STCALL SINTH # SIN(MG) = IGA . OGA 058812,000177: 23,3343 47256 ARCTRIG 058813,000178: 23,3344 02764 STORE MGC 058814,000179: 058815,000180: 23,3345 45246 ABS DSU 058816,000181: 23,3346 07476 .166... 058817,000182: 23,3347 77644 BPL 058818,000183: 23,3350 47371 GIMLOCK1 # IF ANGLE GREATER THAN 60 DEGREES 058819,000184: 058820,000185: 23,3351 50375 CALCGA1 VLOAD DOT 058821,000186: 23,3352 02706 ZSM 058822,000187: 23,3353 00001 0 058823,000188: 23,3354 24021 STOVL COSTH # COS(IG) = ZSM . MGA 058824,000189: 23,3355 02672 XSM 058825,000190: # Page 1360 058826,000191: 23,3356 45441 DOT STADR 058827,000192: 23,3357 43754 STCALL SINTH # SIN(IG) = XSM . MGA 058828,000193: 23,3360 47256 ARCTRIG 058829,000194: 058830,000195: 23,3361 26762 STOVL IGC 058831,000196: 23,3362 02760 OGC 058832,000197: 23,3363 43034 RTB BONCLR 058833,000198: 23,3364 45552 V1STO2S 058834,000199: 23,3365 00200 CPHIFLAG 058835,000200: 23,3366 00051 S2 058836,000201: 23,3367 35156 STCALL THETAD 058837,000202: 23,3370 00051 S2 058838,000203: 058839,000204: 23,3371 77776 GIMLOCK1 EXIT 058840,000205: 23,3372 05650 TC ALARM 058841,000206: 23,3373 00401 OCT 00401 058842,000207: 23,3374 05546 TC UPFLAG # GIMBAL LOCK HAS OCCURRED 058843,000208: 23,3375 00056 ADRES GLOKFAIL 058844,000209: 058845,000210: 23,3376 06006 TC INTPRET 058846,000211: 23,3377 77650 GOTO 058847,000212: 23,3400 47351 CALCGA1 058848,000213: 058849,000214: # Page 1361 058850,000215: # AXISGEN COMPUTES THE COORDINATES OF ONE COORDINATE SYSTEM REFERRED TO ANOTHER COORDINATE SYSTEM. 058851,000216: 058852,000217: # THE INPUTS ARE 1) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM A STORED AT STARAD. 2) THE STAR2 VECTOR 058853,000218: # REFERRED TO COORDINATE SYSTEM A STORED AT STARAD +6. 3) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM B STORED 058854,000219: # AT LOCATION 6 OF THE VAC AREA. 4) THE STAR2 VECTOR REFERRED TO COORDINATE SYSTEM B STORED AT LOCATION 12D OF 058855,000220: # THE VAC AREA. 058856,000221: 058857,000222: # THE OUTPUT DEFINES COORDINATE SYSTEM A REFERRED TO COORDINATE SYSTEM B. THE THREE HALF-UNIT VECTORS ARE STORED 058858,000223: # AT LOCATIONS XDC, XDC +6, XDC +12D, AND STARAD, STARAD +6, STARAD +12D. 058859,000224: 058860,000225: 23,3401 66370 AXISGEN AXT,1 SSP # PUSHDOWN 00-30D, 34D-37D 058861,000226: 23,3402 02743 STARAD +6 058862,000227: 23,3403 00051 S1 058863,000228: 23,3404 02727 STARAD -6 058864,000229: 058865,000230: 23,3405 77601 SETPD 058866,000231: 23,3406 00001 0 058867,000232: 23,3407 46773 AXISGEN1 VLOAD* VXV* # 06D UA = S1 058868,000233: 23,3410 02752 STARAD +12D,1 # STARAD +00D UB = S1 058869,000234: 23,3411 02760 STARAD +18D,1 058870,000235: 23,3412 77656 UNIT # 12D VA = UNIT(S1 X S2) 058871,000236: 23,3413 06760 STORE STARAD +18D,1 # STARAD +06D VB = UNIT(S1 X S2) 058872,000237: 23,3414 77773 VLOAD* 058873,000238: 23,3415 02752 STARAD +12D,1 058874,000239: 058875,000240: 23,3416 76433 VXV* VSL1 058876,000241: 23,3417 02760 STARAD +18D,1 # 18D WA = UA X VA 058877,000242: 23,3420 06766 STORE STARAD +24D,1 # STARAD +12D WB = UB X VB 058878,000243: 058879,000244: 23,3421 77700 TIX,1 058880,000245: 23,3422 47407 AXISGEN1 058881,000246: 058882,000247: 23,3423 66160 AXC,1 SXA,1 058883,000248: 23,3424 00006 6 058884,000249: 23,3425 00036 30D 058885,000250: 058886,000251: 23,3426 66370 AXT,1 SSP 058887,000252: 23,3427 00022 18D 058888,000253: 23,3430 00051 S1 058889,000254: 23,3431 00006 6 058890,000255: 058891,000256: 23,3432 66374 AXT,2 SSP 058892,000257: 23,3433 00006 6 058893,000258: 23,3434 00052 S2 058894,000259: 23,3435 00002 2 058895,000260: 058896,000261: 23,3436 76720 AXISGEN2 XCHX,1 VLOAD* 058897,000262: 23,3437 00036 30D # X1=-6 X2=+6 X1=-6 X2=+4 X1=-6 X2=+2 058898,000263: 23,3440 00001 0,1 058899,000264: 058900,000265: # Page 1362 058901,000266: 23,3441 62757 VXSC* PDVL* # J=(UA)(UB1) J=(UA)(UB2) J=(UA)(UB3) 058902,000267: 23,3442 75033 STARAD +6,2 058903,000268: 23,3443 00007 6,1 058904,000269: 23,3444 77757 VXSC* 058905,000270: 23,3445 75025 STARAD +12D,2 058906,000271: 23,3446 30031 STOVL* 24D # K=(VA)(VB1) J=(VA)(VB2) J=(VA)(VB3) 058907,000272: 23,3447 00015 12D,1 058908,000273: 058909,000274: 23,3450 53357 VXSC* VAD 058910,000275: 23,3451 75017 STARAD +18D,2 # L=(WA)(WB1) J=(WA)(WB2) J=(WA)(WB3) 058911,000276: 23,3452 76455 VAD VSL1 058912,000277: 23,3453 00031 24D 058913,000278: 23,3454 53520 XCHX,1 UNIT 058914,000279: 23,3455 00036 30D 058915,000280: 23,3456 06736 STORE XDC +18D,1 # XDC = L+J+K YDC = L+J+K ZDC = L+J+K 058916,000281: 058917,000282: 23,3457 77700 TIX,1 058918,000283: 23,3460 47461 AXISGEN3 058919,000284: 058920,000285: 23,3461 77704 AXISGEN3 TIX,2 058921,000286: 23,3462 47436 AXISGEN2 058922,000287: 058923,000288: 23,3463 77775 VLOAD 058924,000289: 23,3464 02714 XDC 058925,000290: 23,3465 26736 STOVL STARAD 058926,000291: 23,3466 02722 YDC 058927,000292: 23,3467 26744 STOVL STARAD +6 058928,000293: 23,3470 02730 ZDC 058929,000294: 23,3471 02752 STORE STARAD +12D 058930,000295: 058931,000296: 23,3472 77616 RVQ 058932,000297: 058933,000298: # Page 1363 058934,000299: 23,3473 05520 26075 QTSN45 2DEC .1768 058935,000300: 23,3475 05252 25253 .166... 2DEC .1666666667 058936,000301: 058937,000302: # Page 1364 (empty page) 058938,000303: 058939,000304: End of include-file INFLIGHT_ALIGNMENT_ROUTINES.agc. Parent file is MAIN.agc