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. |
052587,000002: ## Copyright: Public domain.
052588,000003: ## Filename: INFLIGHT_ALIGNMENT_ROUTINES.agc
052589,000004: ## Purpose: A section of Luminary revision 116.
052590,000005: ## It is part of the source code for the Lunar Module's (LM)
052591,000006: ## Apollo Guidance Computer (AGC) for Apollo 12.
052592,000007: ## This file is intended to be a faithful transcription, except
052593,000008: ## that the code format has been changed to conform to the
052594,000009: ## requirements of the yaYUL assembler rather than the
052595,000010: ## original YUL assembler.
052596,000011: ## Reference: pp. 1239-1248
052597,000012: ## Assembler: yaYUL
052598,000013: ## Contact: Ron Burkey <info@sandroid.org>.
052599,000014: ## Website: www.ibiblio.org/apollo/index.html
052600,000015: ## Mod history: 2017-01-22 MAS Created from Luminary 99.
052601,000016: ## 2017-01-26 RRB Updated for Luminary 116.
052602,000017: ## 2017-03-13 RSB Proofed comment text via 3-way diff vs
052603,000018: ## Luminary 99 and 131, but no changes were needed.
052604,000019: ## 2017-03-17 RSB Comment-text fixes identified in diff'ing
052605,000020: ## Luminary 99 vs Comanche 55.
052606,000021:
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Page 1239 |
052608,000023: 22,3773 BANK 22
052609,000024: 23,2000 SETLOC INFLIGHT
052610,000025: 23,2000 BANK
052611,000026:
052612,000027: 23,3251 E5,1642 EBANK= XSM
052613,000028:
052614,000029: # CALCGTA COMPUTES THE GYRO TORQUE ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
052615,000030:
052616,000031: # THE INPUT IS THE DESIRED STABLE MEMBER COORDINATES REFERRED TO PRESENT STABLE MEMBER COORDINATES. THE THREE
052617,000032: # HALF-UNIT VECTORS ARE STORED AT XDC, YDC, AND ZDC.
052618,000033:
052619,000034: # THE OUTPUTS ARE THE THREE GYRO TORQUING ANGLES TO BE APPLIED TO THE Y, Z, AND X GYROS AND ARE STORED DP AT IGC,
052620,000035: # MGC, AND OGC RESPECTIVELY.
052621,000036:
052622,000037: 23,3251 COUNT* $$/INFLT
052623,000038: 23,3251 71220 CALCGTA ITA DLOAD # PUSHDOWN 00-03, 16D-27D, 34D-37D
052624,000039: 23,3252 00051 S2 # XDC = (XD1 XD2 XD3)
052625,000040: 23,3253 02665 XDC # YDC = (YD1 YD2 YD3)
052626,000041: 23,3254 65325 PDDL PDDL # ZDC = (ZD1 ZD2 ZD3)
052627,000042: 23,3255 06524 HI6ZEROS
052628,000043: 23,3256 02671 XDC +4
052629,000044: 23,3257 55476 DCOMP VDEF
052630,000045: 23,3260 77656 UNIT
052631,000046: 23,3261 14027 STODL ZPRIME # ZP = UNIT(-XD3 0 XD1) = (ZP1 ZP2 ZP3)
052632,000047: 23,3262 00027 ZPRIME
052633,000048:
052634,000049: 23,3263 77742 SR1
052635,000050: 23,3264 14023 STODL SINTH # SIN(IGC) = ZP1
052636,000051: 23,3265 00033 ZPRIME +4
052637,000052: 23,3266 77742 SR1
052638,000053: 23,3267 34021 STCALL COSTH # COS(IGC) = ZP3
052639,000054: 23,3270 47322 ARCTRIG
052640,000055:
052641,000056: 23,3271 16742 STODL IGC # Y GYRO TORQUING ANGLE FRACTION OF REV.
052642,000057: 23,3272 02667 XDC +2
052643,000058: 23,3273 77742 SR1
052644,000059: 23,3274 14023 STODL SINTH # SIN(MGC) = XD2
052645,000060: 23,3275 00027 ZPRIME
052646,000061:
052647,000062: 23,3276 65205 DMP PDDL
052648,000063: 23,3277 02671 XDC +4 # PD00 = (ZP1)(XD3)
052649,000064: 23,3300 00033 ZPRIME +4
052650,000065:
052651,000066: 23,3301 45205 DMP DSU
052652,000067: 23,3302 02665 XDC # MPAC = (ZP3)(XD1)
052653,000068: 23,3303 77626 STADR
052654,000069: 23,3304 43756 STCALL COSTH # COS(MGC) = MPAC - PD00
052655,000070: 23,3305 47322 ARCTRIG
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Page 1240 |
052657,000072: 23,3306 26744 STOVL MGC # Z GYRO TORQUING ANGLE FRACTION OF REV.
052658,000073: 23,3307 00027 ZPRIME
052659,000074: 23,3310 77641 DOT
052660,000075: 23,3311 02701 ZDC
052661,000076: 23,3312 24021 STOVL COSTH # COS(OGC) = ZP . ZDC
052662,000077: 23,3313 00027 ZPRIME
052663,000078: 23,3314 77641 DOT
052664,000079: 23,3315 02673 YDC
052665,000080: 23,3316 34023 STCALL SINTH # SIN(OGC) = ZP . YDC
052666,000081: 23,3317 47322 ARCTRIG
052667,000082:
052668,000083: 23,3320 36740 STCALL OGC # X GYRO TORQUING ANGLE FRACTION OF REV.
052669,000084: 23,3321 00051 S2
052670,000085:
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Page 1241 |
052672,000087: # ARCTRIG COMPUTES AN ANGLE GIVEN THE SINE AND COSINE OF THIS ANGLE.
052673,000088:
052674,000089: # THE INPUTS ARE SIN/4 AND COS/4 STORED DP AT SINTH AND COSTH.
052675,000090:
052676,000091: # THE OUTPUT IS THE CALCULATED ANGLE BETWEEN +.5 AND -.5 REVOLUTIONS AND STORED AT THETA. THE OUTPUT IS ALSO
052677,000092: # AVAILABLE AT MPAC.
052678,000093:
052679,000094: 23,3322 51545 ARCTRIG DLOAD ABS # PUSHDOWN 16D-21D
052680,000095: 23,3323 00023 SINTH
052681,000096: 23,3324 50025 DSU BMN
052682,000097: 23,3325 07536 QTSN45 # ABS(SIN/4) - SIN(45)/4
052683,000098: 23,3326 47335 TRIG1 # IF (-45,45) OR (135,-135)
052684,000099:
052685,000100: 23,3327 72545 DLOAD SL1 # (45,135) OR (-135,-45)
052686,000101: 23,3330 00021 COSTH
052687,000102: 23,3331 75326 ACOS SIGN
052688,000103: 23,3332 00023 SINTH
052689,000104: 23,3333 00025 STORE THETA # X = ARCCOS(COS) WITH SIGN(SIN)
052690,000105: 23,3334 77616 RVQ
052691,000106:
052692,000107: 23,3335 72545 TRIG1 DLOAD SL1 # (-45,45) OR (135,-135)
052693,000108: 23,3336 00023 SINTH
052694,000109: 23,3337 77736 ASIN
052695,000110: 23,3340 14025 STODL THETA # X = ARCSIN(SIN) WITH SIGN(SIN)
052696,000111: 23,3341 00021 COSTH
052697,000112: 23,3342 77640 BMN
052698,000113: 23,3343 47346 TRIG2 # IF (135,-135)
052699,000114:
052700,000115: 23,3344 43545 DLOAD RVQ
052701,000116: 23,3345 00025 THETA # X = ARCSIN(SIN) (-45,45)
052702,000117:
052703,000118: 23,3346 75345 TRIG2 DLOAD SIGN # (135,-135)
052704,000119: 23,3347 06522 HIDPHALF
052705,000120: 23,3350 00023 SINTH
052706,000121: 23,3351 77625 DSU
052707,000122: 23,3352 00025 THETA
052708,000123: 23,3353 00025 STORE THETA # X = .5 WITH SIGN(SIN) - ARCSIN(SIN)
052709,000124: 23,3354 77616 RVQ # (+) - (+) OR (-) - (-)
052710,000125:
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Page 1242 |
052712,000127: # SMNB, NBSM, AND AXISROT, WHICH USED TO APPEAR HERE, HAVE BEEN
052713,000128: # COMBINED IN A ROUTINE CALLED AX*SR*T, WHICH APPEARS AMONG THE POWERED
052714,000129: # FLIGHT SUBROUTINES.
052715,000130:
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Page 1243 |
052717,000132: # CALCGA COMPUTES THE CDU DRIVING ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
052718,000133:
052719,000134: # THE INPUTS ARE 1) THE NAVIGATION BASE COORDINATES REFERRED TO ANY COORDINATE SYSTEM. THE THREE HALF-UNIT
052720,000135: # VECTORS ARE STORED AT XNB,YNB, AND ZNB. 2) THE DESIRED STABLE MEMBER COORDINATES REFERRED TO THE SAME
052721,000136: # COORDINATE SYSTEM ARE STORED AT XSM, YSM, AND ZSM.
052722,000137:
052723,000138: # THE OUTPUTS ARE THE THREE CDU DRIVING ANGLES AND ARE STORED SP AT THETAD, THETAD +1, AND THETAD +2.
052724,000139:
052725,000140: 23,3355 77601 CALCGA SETPD # PUSHDOWN 00-05, 16D-21D, 34D-37D
052726,000141: 23,3356 00001 0
052727,000142: 23,3357 47375 VLOAD VXV
052728,000143: 23,3360 02665 XNB # XNB = OGA (OUTER GIMBAL AXIS)
052729,000144: 23,3361 02651 YSM # YSM = IGA (INNER GIMBAL AXIS)
052730,000145: 23,3362 41456 UNIT PUSH # PD0 = UNIT(OGA X IGA) = MGA
052731,000146:
052732,000147: 23,3363 44041 DOT ITA
052733,000148: 23,3364 02701 ZNB
052734,000149: 23,3365 00051 S2
052735,000150: 23,3366 24021 STOVL COSTH # COS(OG) = MGA . ZNB
052736,000151: 23,3367 00001 0
052737,000152: 23,3370 77641 DOT
052738,000153: 23,3371 02673 YNB
052739,000154: 23,3372 34023 STCALL SINTH # SIN(OG) = MGA . YNB
052740,000155: 23,3373 47322 ARCTRIG
052741,000156: 23,3374 26740 STOVL OGC
052742,000157: 23,3375 00001 0
052743,000158:
052744,000159: 23,3376 50235 VXV DOT # PROVISION FOR MG ANGLE OF 90 DEGREES
052745,000160: 23,3377 02665 XNB
052746,000161: 23,3400 02651 YSM
052747,000162: 23,3401 77752 SL1
052748,000163: 23,3402 24021 STOVL COSTH # COS(MG) = IGA . (MGA X OGA)
052749,000164: 23,3403 02651 YSM
052750,000165: 23,3404 77641 DOT
052751,000166: 23,3405 02665 XNB
052752,000167: 23,3406 34023 STCALL SINTH # SIN(MG) = IGA . OGA
052753,000168: 23,3407 47322 ARCTRIG
052754,000169: 23,3410 02744 STORE MGC
052755,000170:
052756,000171: 23,3411 45246 ABS DSU
052757,000172: 23,3412 07540 .166...
052758,000173: 23,3413 77644 BPL
052759,000174: 23,3414 47433 GIMLOCK1 # IF ANGLE GREATER THAN 60 DEGREES
052760,000175:
052761,000176: 23,3415 50375 CALCGA1 VLOAD DOT
052762,000177: 23,3416 02657 ZSM
052763,000178: 23,3417 00001 0
052764,000179: 23,3420 24021 STOVL COSTH # COS(IG) = ZSM . MGA
052765,000180: 23,3421 02643 XSM
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Page 1244 |
052767,000182: 23,3422 45441 DOT STADR
052768,000183: 23,3423 43754 STCALL SINTH # SIN(IG) = XSM . MGA
052769,000184: 23,3424 47322 ARCTRIG
052770,000185:
052771,000186: 23,3425 26742 STOVL IGC
052772,000187: 23,3426 02740 OGC
052773,000188: 23,3427 77634 RTB
052774,000189: 23,3430 21621 V1STO2S
052775,000190: 23,3431 34322 STCALL THETAD
052776,000191: 23,3432 00051 S2
052777,000192:
052778,000193: 23,3433 77776 GIMLOCK1 EXIT
052779,000194: 23,3434 05567 TC ALARM
052780,000195: 23,3435 00401 OCT 00401
052781,000196: 23,3436 05504 TC UPFLAG # GIMBAL LOCK HAS OCCURED
052782,000197: 23,3437 00056 ADRES GLOKFAIL
052783,000198:
052784,000199: 23,3440 06042 TC INTPRET
052785,000200: 23,3441 77650 GOTO
052786,000201: 23,3442 47415 CALCGA1
052787,000202:
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Page 1245 |
052789,000204: # AXISGEN COMPUTES THE COORDINATES OF ONE COORDINATE SYSTEM REFERRED TO ANOTHER COORDINATE SYSTEM.
052790,000205:
052791,000206: # THE INPUTS ARE 1) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM A STORED AT STARAD. 2) THE STAR2 VECTOR
052792,000207: # REFERRED TO COORDINATE SYSTEM A STORED AT STARAD +6. 3) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM B STORED
052793,000208: # AT LOCATION 6 OF THE VAC AREA. 4) THE STAR2 VECTOR REFERRED TO COORDINATE SYSTEM B STORED AT LOCATION 12D OF
052794,000209: # THE VAC AREA.
052795,000210:
052796,000211: # THE OUTPUT DEFINES COORDINATE SYSTEM A REFERRED TO COORDINATE SYSTEM B. THE THREE HALF-UNIT VECTORS ARE STORED
052797,000212: # AT LOCATIONS XDC, XDC +6, XDC +12D, AND STARAD, STARAD +6, STARAD +12D.
052798,000213:
052799,000214: 23,3443 66370 AXISGEN AXT,1 SSP # PUSHDOWN 00-30D, 34D-37D
052800,000215: 23,3444 02714 STARAD +6
052801,000216: 23,3445 00051 S1
052802,000217: 23,3446 02700 STARAD -6
052803,000218:
052804,000219: 23,3447 77601 SETPD
052805,000220: 23,3450 00001 0
052806,000221: 23,3451 46773 AXISGEN1 VLOAD* VXV* # 06D UA = S1
052807,000222: 23,3452 02723 STARAD +12D,1 # STARAD +00D UB = S1
052808,000223: 23,3453 02731 STARAD +18D,1
052809,000224: 23,3454 77656 UNIT # 12D VA = UNIT(S1 X S2)
052810,000225: 23,3455 06731 STORE STARAD +18D,1 # STARAD +06D VB = UNIT(S1 X S2)
052811,000226: 23,3456 77773 VLOAD*
052812,000227: 23,3457 02723 STARAD +12D,1
052813,000228:
052814,000229: 23,3460 76433 VXV* VSL1
052815,000230: 23,3461 02731 STARAD +18D,1 # 18D WA = UA X VA
052816,000231: 23,3462 06737 STORE STARAD +24D,1 # STARAD +12D WB = UB X VB
052817,000232:
052818,000233: 23,3463 77700 TIX,1
052819,000234: 23,3464 47451 AXISGEN1
052820,000235:
052821,000236: 23,3465 66160 AXC,1 SXA,1
052822,000237: 23,3466 00006 6
052823,000238: 23,3467 00036 30D
052824,000239:
052825,000240: 23,3470 66370 AXT,1 SSP
052826,000241: 23,3471 00022 18D
052827,000242: 23,3472 00051 S1
052828,000243: 23,3473 00006 6
052829,000244:
052830,000245: 23,3474 66374 AXT,2 SSP
052831,000246: 23,3475 00006 6
052832,000247: 23,3476 00052 S2
052833,000248: 23,3477 00002 2
052834,000249:
052835,000250: 23,3500 76720 AXISGEN2 XCHX,1 VLOAD*
052836,000251: 23,3501 00036 30D # X1=-6 X2=+6 X1=-6 X2=+4 X1=-6 X2=+2
052837,000252: 23,3502 00001 0,1
052838,000253:
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Page 1246 |
052840,000255: 23,3503 62757 VXSC* PDVL* # J=(UA)(UB1) J=(UA)(UB2) J=(UA)(UB3)
052841,000256: 23,3504 75062 STARAD +6,2
052842,000257: 23,3505 00007 6,1
052843,000258: 23,3506 77757 VXSC*
052844,000259: 23,3507 75054 STARAD +12D,2
052845,000260: 23,3510 30031 STOVL* 24D # K=(VA)(VB1) J=(VA)(VB2) J=(VA)(VB3)
052846,000261: 23,3511 00015 12D,1
052847,000262:
052848,000263: 23,3512 53357 VXSC* VAD
052849,000264: 23,3513 75046 STARAD +18D,2 # L=(WA)(WB1) J=(WA)(WB2) J=(WA)(WB3)
052850,000265: 23,3514 76455 VAD VSL1
052851,000266: 23,3515 00031 24D
052852,000267: 23,3516 53520 XCHX,1 UNIT
052853,000268: 23,3517 00036 30D
052854,000269: 23,3520 06707 STORE XDC +18D,1 # XDC = L+J+K YDC = L+J+K ZDC = L+J+K
052855,000270:
052856,000271: 23,3521 77700 TIX,1
052857,000272: 23,3522 47523 AXISGEN3
052858,000273:
052859,000274: 23,3523 77704 AXISGEN3 TIX,2
052860,000275: 23,3524 47500 AXISGEN2
052861,000276:
052862,000277: 23,3525 77775 VLOAD
052863,000278: 23,3526 02665 XDC
052864,000279: 23,3527 26707 STOVL STARAD
052865,000280: 23,3530 02673 YDC
052866,000281: 23,3531 26715 STOVL STARAD +6
052867,000282: 23,3532 02701 ZDC
052868,000283: 23,3533 02723 STORE STARAD +12D
052869,000284:
052870,000285: 23,3534 77616 RVQ
052871,000286:
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Page 1247 |
052873,000288: 23,3535 05520 26075 QTSN45 2DEC .1768
052874,000289:
052875,000290: 23,3537 05252 25253 .166... 2DEC .1666666667
052876,000291:
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Page 1248
Empty page |
End of include-file INFLIGHT_ALIGNMENT_ROUTINES.agc. Parent file is MAIN.agc