ASSEMBLE REVISION 249 OF AGC PROGRAM COLOSSUS BY NASA 2021111-041 20'35 OCT. 28,1968Note that the date is the date of the printout, not the date of the program revision.
Source Code
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This is the source-code for the Apollo 9 Command Module's Guidance Computer.
These files were derived originally from the scan from MIT's Dibner Institute's
now-discontinued website titled "History of Recent Science and Technology", which
in turn was originally created by Gary Neff, though his high-quality scans were
unfortunately reduced in legibility when presented online.
The markings on the front of the
printout imply that it was the original AGC developer Norm Brodeur's copy.
A scan by Ron Burkey has superceded it, made from a more-legible copy from the collection of original
AGC developer Fred Martin. The source code was transcribed from
those images by Ron Burkey. Note that the page images
presented online are of reduced quality, and that higher-quality images
are available. Report any conversion errors or legibility
problems in page images to info@sandroid.org.
Notations on the program listing read, in part:ASSEMBLE REVISION 249 OF AGC PROGRAM COLOSSUS BY NASA 2021111-041 20'35 OCT. 28,1968Note that the date is the date of the printout, not the date of the program revision. |
057941,000002: ## Copyright: Public domain.
057942,000003: ## Filename: INFLIGHT_ALIGNMENT_ROUTINES.agc
057943,000004: ## Purpose: Part of the source code for Colossus, build 249.
057944,000005: ## It is part of the source code for the Command Module's (CM)
057945,000006: ## Apollo Guidance Computer (AGC), for Apollo 9.
057946,000007: ## Assembler: yaYUL
057947,000008: ## Reference: Starts on p. 1323
057948,000009: ## Contact: Ron Burkey <info@sandroid.org>.
057949,000010: ## Website: www.ibiblio.org/apollo.
057950,000011: ## Mod history: 08/29/04 RSB. Adapted from corresponding Luminary131 file.
057951,000012: ## 2017-01-06 RSB Page numbers now agree with those on the
057952,000013: ## original harcopy, as opposed to the PDF page
057953,000014: ## numbers in 1701.pdf.
057954,000015: ## 2017-01-14 RSB Cross-diff'd comment text (not whitespace)
057955,000016: ## vs the already-proofed corresponding Colossus
057956,000017: ## 237 and Comanche 55 source-code files
057957,000018: ## and corrected errors found. After corrections,
057958,000019: ## there were no text-comment differences between
057959,000020: ## the different versions.
057960,000021: ##
057961,000022: ## The contents of the "Colossus249" files, in general, are transcribed
057962,000023: ## from a scanned copy of the program listing. Notations on this
057963,000024: ## document read, in part:
057964,000025: ##
057965,000026: ## Assemble revision 249 of AGC program Colossus by NASA
057966,000027: ## 2021111-041. October 28, 1968.
057967,000028: ##
057968,000029: ## This AGC program shall also be referred to as
057969,000030: ## Colossus 1A
057970,000031: ##
057971,000032: ## Prepared by
057972,000033: ## Massachusetts Institute of Technology
057973,000034: ## 75 Cambridge Parkway
057974,000035: ## Cambridge, Massachusetts
057975,000036: ## under NASA contract NAS 9-4065.
057976,000037: ##
057977,000038: ## Refer directly to the online document mentioned above for further information.
057978,000039: ## Please report any errors (relative to the scanned pages) to info@sandroid.org.
057979,000040: ##
057980,000041: ## In some cases, where the source code for Luminary 131 overlaps that of
057981,000042: ## Colossus 249, this code is instead copied from the corresponding Luminary 131
057982,000043: ## source file, and then is proofed to incorporate any changes.
057983,000044:
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Page 1323 |
057985,000046: 22,3505 BANK 22
057986,000047: 23,2000 SETLOC INFLIGHT
057987,000048: 23,2000 BANK
057988,000049:
057989,000050: 23,3140 E5,1671 EBANK= XSM
057990,000051:
057991,000052: # CALCGTA COMPUTES THE GYRO TORQUE ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
057992,000053:
057993,000054: # THE INPUT IS THE DESIRED STABLE MEMBER COORDINATES REFERRED TO PRESENT STABLE MEMBER COORDINATES. THE THREE
057994,000055: # HALF-UNIT VECTORS ARE STORED AT XDC, YDC, AND ZDC.
057995,000056:
057996,000057: # THE OUTPUTS ARE THE THREE GYRO TORQUING ANGLES TO BE APPLIED TO THE Y, Z, AND X GYROS AND ARE STORED DP AT IGC,
057997,000058: # MGC, AND OGC RESPECTIVELY.
057998,000059:
057999,000060: 23,3140 COUNT 23/INFLT
058000,000061:
058001,000062: 23,3140 71220 CALCGTA ITA DLOAD # PUSHDOWN 00-03, 16D-27D, 34D-37D
058002,000063: 23,3141 00051 S2 # XDC = (XD1 XD2 XD3)
058003,000064: 23,3142 02714 XDC # YDC = (YD1 YD2 YD3)
058004,000065: 23,3143 65325 PDDL PDDL # ZDC = (ZD1 ZD2 ZD3)
058005,000066: 23,3144 15332 HI6ZEROS
058006,000067: 23,3145 02720 XDC +4
058007,000068: 23,3146 55476 DCOMP VDEF
058008,000069: 23,3147 77656 UNIT
058009,000070: 23,3150 14027 STODL ZPRIME # ZP = UNIT(-XD3 0 XD1) = (ZP1 ZP2 ZP3)
058010,000071: 23,3151 00027 ZPRIME
058011,000072:
058012,000073: 23,3152 77742 SR1
058013,000074: 23,3153 14023 STODL SINTH # SIN(IGC) = ZP1
058014,000075: 23,3154 00033 ZPRIME +4
058015,000076: 23,3155 77742 SR1
058016,000077: 23,3156 34021 STCALL COSTH # COS(IGC) = ZP3
058017,000078: 23,3157 47211 ARCTRIG
058018,000079:
058019,000080: 23,3160 16762 STODL IGC # Y GYRO TORQUING ANGLE FRACTION OF REV.
058020,000081: 23,3161 02716 XDC +2
058021,000082: 23,3162 77742 SR1
058022,000083: 23,3163 14023 STODL SINTH # SIN(MGC) = XD2
058023,000084: 23,3164 00027 ZPRIME
058024,000085:
058025,000086: 23,3165 65205 DMP PDDL
058026,000087: 23,3166 02720 XDC +4 # PD00 = (ZP1)(XD3)
058027,000088: 23,3167 00033 ZPRIME +4
058028,000089:
058029,000090: 23,3170 45205 DMP DSU
058030,000091: 23,3171 02714 XDC # MPAC = (ZP3)(XD1)
058031,000092: 23,3172 77626 STADR
058032,000093: 23,3173 43756 STCALL COSTH # COS(MGC) = MPAC - PD00
058033,000094: 23,3174 47211 ARCTRIG
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Page 1324 |
058035,000096: 23,3175 26764 STOVL MGC # Z GYRO TORQUING ANGLE FRACTION OF REV.
058036,000097: 23,3176 00027 ZPRIME
058037,000098: 23,3177 77641 DOT
058038,000099: 23,3200 02730 ZDC
058039,000100: 23,3201 24021 STOVL COSTH # COS(OGC) = ZP . ZDC
058040,000101: 23,3202 00027 ZPRIME
058041,000102: 23,3203 77641 DOT
058042,000103: 23,3204 02722 YDC
058043,000104: 23,3205 34023 STCALL SINTH # SIN(OGC) = ZP . YDC
058044,000105: 23,3206 47211 ARCTRIG
058045,000106:
058046,000107: 23,3207 36760 STCALL OGC # X GYRO TORQUING ANGLE FRACTION OF REV.
058047,000108: 23,3210 00051 S2
058048,000109:
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Page 1325 |
058050,000111: # ARCTRIG COMPUTES AN ANGLE GIVEN THE SINE AND COSINE OF THIS ANGLE.
058051,000112:
058052,000113: # THE INPUTS ARE SIN/4 AND COS/4 STORED DP AT SINTH AND COSTH.
058053,000114:
058054,000115: # THE OUTPUT IS THE CALCULATED ANGLE BETWEEN +.5 AND -.5 REVOLUTIONS AND STORED AT THETA. THE OUTPUT IS ALSO
058055,000116: # AVAILABLE AT MPAC.
058056,000117:
058057,000118: 23,3211 51545 ARCTRIG DLOAD ABS # PUSHDOWN 16D-21D
058058,000119: 23,3212 00023 SINTH
058059,000120: 23,3213 50025 DSU BMN
058060,000121: 23,3214 07427 QTSN45 # ABS(SIN/4) - SIN(45)/4
058061,000122: 23,3215 47224 TRIG1 # IF (-45,45) OR (135,-135)
058062,000123:
058063,000124: 23,3216 72545 DLOAD SL1 # (45,135) OR (-135,-45)
058064,000125: 23,3217 00021 COSTH
058065,000126: 23,3220 75326 ACOS SIGN
058066,000127: 23,3221 00023 SINTH
058067,000128: 23,3222 00025 STORE THETA # X = ARCCOS(COS) WITH SIGN(SIN)
058068,000129: 23,3223 77616 RVQ
058069,000130:
058070,000131: 23,3224 72545 TRIG1 DLOAD SL1 # (-45,45) OR (135,-135)
058071,000132: 23,3225 00023 SINTH
058072,000133: 23,3226 77736 ASIN
058073,000134: 23,3227 14025 STODL THETA # X = ARCSIN(SIN) WITH SIGN(SIN)
058074,000135: 23,3230 00021 COSTH
058075,000136: 23,3231 77640 BMN
058076,000137: 23,3232 47235 TRIG2 # IF (135,-135)
058077,000138:
058078,000139: 23,3233 43545 DLOAD RVQ
058079,000140: 23,3234 00025 THETA # X = ARCSIN(SIN) (-45,45)
058080,000141:
058081,000142: 23,3235 75345 TRIG2 DLOAD SIGN # (135,-135)
058082,000143: 23,3236 15330 HIDPHALF
058083,000144: 23,3237 00023 SINTH
058084,000145: 23,3240 77625 DSU
058085,000146: 23,3241 00025 THETA
058086,000147: 23,3242 00025 STORE THETA # X = .5 WITH SIGN(SIN) - ARCSIN(SIN)
058087,000148: 23,3243 77616 RVQ # (+) - (+) OR (-) - (-)
058088,000149:
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Page 1326 |
058090,000151: # SMNB, NBSM, AND AXISROT, WHICH USED TO APPEAR HERE, HAVE BEEN
058091,000152: # COMBINED IN A ROUTINE CALLED AX*SR*T, WHICH APPEARS AMONG THE POWERED
058092,000153: # FLIGHT SUBROUTINES.
058093,000154:
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Page 1327 |
058095,000156: # CALCGA COMPUTES THE CDU DRIVING ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
058096,000157:
058097,000158: # THE INPUTS ARE 1) THE NAVIGATION BASE COORDINATES REFERRED TO ANY COORDINATE SYSTEM. THE THREE HALF-UNIT
058098,000159: # VECTORS ARE STORED AT XNB, YNB, AND ZNB. 2) THE DESIRED STABLE MEMBER COORDINATES REFERRED TO THE SAME
058099,000160: # COORDINATE SYSTEM ARE STORED AT XSM, YSM, AND ZSM.
058100,000161:
058101,000162: # THE OUTPUTS ARE THE THREE CDU DRIVING ANGLES AND ARE STORED SP AT THETAD, THETAD +1, AND THETAD +2.
058102,000163:
058103,000164: 23,3244 77601 CALCGA SETPD # PUSHDOWN 00-05, 16D-21D, 34D-37D
058104,000165: 23,3245 00001 0
058105,000166: 23,3246 47375 VLOAD VXV
058106,000167: 23,3247 02714 XNB # XNB = OGA (OUTER GIMBAL AXIS)
058107,000168: 23,3250 02700 YSM # YSM = IGA (INNER GIMBAL AXIS)
058108,000169: 23,3251 41456 UNIT PUSH # PD0 = UNIT(OGA X IGA) = MGA
058109,000170:
058110,000171: 23,3252 44041 DOT ITA
058111,000172: 23,3253 02730 ZNB
058112,000173: 23,3254 00051 S2
058113,000174: 23,3255 24021 STOVL COSTH # COS(OG) = MGA . ZNB
058114,000175: 23,3256 00001 0
058115,000176: 23,3257 77641 DOT
058116,000177: 23,3260 02722 YNB
058117,000178: 23,3261 34023 STCALL SINTH # SIN(OG) = MGA . YNB
058118,000179: 23,3262 47211 ARCTRIG
058119,000180: 23,3263 26760 STOVL OGC
058120,000181: 23,3264 00001 0
058121,000182:
058122,000183: 23,3265 50235 VXV DOT # PROVISION FOR MG ANGLE OF 90 DEGREES
058123,000184: 23,3266 02714 XNB
058124,000185: 23,3267 02700 YSM
058125,000186: 23,3270 77752 SL1
058126,000187: 23,3271 24021 STOVL COSTH # COS(MG) = IGA . (MGA X OGA)
058127,000188: 23,3272 02700 YSM
058128,000189: 23,3273 77641 DOT
058129,000190: 23,3274 02714 XNB
058130,000191: 23,3275 34023 STCALL SINTH # SIN(MG) = IGA . OGA
058131,000192: 23,3276 47211 ARCTRIG
058132,000193: 23,3277 02764 STORE MGC
058133,000194:
058134,000195: 23,3300 45246 ABS DSU
058135,000196: 23,3301 07431 .166...
058136,000197: 23,3302 77644 BPL
058137,000198: 23,3303 47324 GIMLOCK1 # IF ANGLE GREATER THAN 60 DEGREES
058138,000199:
058139,000200: 23,3304 50375 CALCGA1 VLOAD DOT
058140,000201: 23,3305 02706 ZSM
058141,000202: 23,3306 00001 0
058142,000203: 23,3307 24021 STOVL COSTH # COS(IG) = ZSM . MGA
058143,000204: 23,3310 02672 XSM
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Page 1328 |
058145,000206: 23,3311 45441 DOT STADR
058146,000207: 23,3312 43754 STCALL SINTH # SIN(IG) = XSM . MGA
058147,000208: 23,3313 47211 ARCTRIG
058148,000209:
058149,000210: 23,3314 26762 STOVL IGC
058150,000211: 23,3315 02760 OGC
058151,000212: 23,3316 43034 RTB BONCLR
058152,000213: 23,3317 45547 V1STO2S
058153,000214: 23,3320 00200 CPHIFLAG
058154,000215: 23,3321 00051 S2
058155,000216: 23,3322 35156 STCALL THETAD
058156,000217: 23,3323 00051 S2
058157,000218:
058158,000219: 23,3324 77776 GIMLOCK1 EXIT
058159,000220: 23,3325 05537 TC ALARM
058160,000221: 23,3326 00401 OCT 00401
058161,000222: 23,3327 05435 TC UPFLAG # GIMBAL LOCK HAS OCCURED
058162,000223: 23,3330 00056 ADRES GLOKFAIL
058163,000224:
058164,000225: 23,3331 06006 TC INTPRET
058165,000226: 23,3332 77650 GOTO
058166,000227: 23,3333 47304 CALCGA1
058167,000228:
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Page 1329 |
058169,000230: # AXISGEN COMPUTES THE COORDINATES OF ONE COORDINATE SYSTEM REFERRED TO ANOTHER COORDINATE SYSTEM.
058170,000231:
058171,000232: # THE INPUTS ARE 1) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM A STORED AT STARAD. 2) THE STAR2 VECTOR
058172,000233: # REFERRED TO COORDINATE SYSTEM A STORED AT STARAD +6. 3) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM B STORED
058173,000234: # AT LOCATION 6 OF THE VAC AREA. 4) THE STAR2 VECTOR REFERRED TO COORDINATE SYSTEM B STORED AT LOCATION 12D OF
058174,000235: # THE VAC AREA.
058175,000236:
058176,000237: # THE OUTPUT DEFINES COORDINATE SYSTEM A REFERRED TO COORDINATE SYSTEM B. THE THREE HALF-UNIT VECTORS ARE STORED
058177,000238: # AT LOCATIONS XDC, XDC +6, XDC +12D, AND STARAD, STARAD +6, STARAD +12D.
058178,000239:
058179,000240: 23,3334 66370 AXISGEN AXT,1 SSP # PUSHDOWN 00-30D, 34D-37D
058180,000241: 23,3335 02743 STARAD +6
058181,000242: 23,3336 00051 S1
058182,000243: 23,3337 02727 STARAD -6
058183,000244:
058184,000245: 23,3340 77601 SETPD
058185,000246: 23,3341 00001 0
058186,000247: 23,3342 46773 AXISGEN1 VLOAD* VXV* # 06D UA = S1
058187,000248: 23,3343 02752 STARAD +12D,1 # STARAD +00D UB = S1
058188,000249: 23,3344 02760 STARAD +18D,1
058189,000250: 23,3345 77656 UNIT # 12D VA = UNIT(S1 X S2)
058190,000251: 23,3346 06760 STORE STARAD +18D,1 # STARAD +06D VB = UNIT(S1 X S2)
058191,000252: 23,3347 77773 VLOAD*
058192,000253: 23,3350 02752 STARAD +12D,1
058193,000254:
058194,000255: 23,3351 76433 VXV* VSL1
058195,000256: 23,3352 02760 STARAD +18D,1 # 18D WA = UA X VA
058196,000257: 23,3353 06766 STORE STARAD +24D,1 # STARAD +12D WB = UB X VB
058197,000258:
058198,000259: 23,3354 77700 TIX,1
058199,000260: 23,3355 47342 AXISGEN1
058200,000261:
058201,000262: 23,3356 66160 AXC,1 SXA,1
058202,000263: 23,3357 00006 6
058203,000264: 23,3360 00036 30D
058204,000265:
058205,000266: 23,3361 66370 AXT,1 SSP
058206,000267: 23,3362 00022 18D
058207,000268: 23,3363 00051 S1
058208,000269: 23,3364 00006 6
058209,000270:
058210,000271: 23,3365 66374 AXT,2 SSP
058211,000272: 23,3366 00006 6
058212,000273: 23,3367 00052 S2
058213,000274: 23,3370 00002 2
058214,000275:
058215,000276: 23,3371 76720 AXISGEN2 XCHX,1 VLOAD*
058216,000277: 23,3372 00036 30D # X1=-6 X2=+6 X1=-6 X2=+4 X1=-6 X2=+2
058217,000278: 23,3373 00001 0,1
058218,000279:
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Page 1330 |
058220,000281: 23,3374 62757 VXSC* PDVL* # J=(UA)(UB1) J=(UA)(UB2) J=(UA)(UB3)
058221,000282: 23,3375 75033 STARAD +6,2
058222,000283: 23,3376 00007 6,1
058223,000284: 23,3377 77757 VXSC*
058224,000285: 23,3400 75025 STARAD +12D,2
058225,000286: 23,3401 30031 STOVL* 24D # K=(VA)(VB1) J=(VA)(VB2) J=(VA)(VB3)
058226,000287: 23,3402 00015 12D,1
058227,000288:
058228,000289: 23,3403 53357 VXSC* VAD
058229,000290: 23,3404 75017 STARAD +18D,2 # L=(WA)(WB1) J=(WA)(WB2) J=(WA)(WB3)
058230,000291: 23,3405 76455 VAD VSL1
058231,000292: 23,3406 00031 24D
058232,000293: 23,3407 53520 XCHX,1 UNIT
058233,000294: 23,3410 00036 30D
058234,000295: 23,3411 06736 STORE XDC +18D,1 # XDC = L+J+K YDC = L+J+K ZDC = L+J+K
058235,000296:
058236,000297: 23,3412 77700 TIX,1
058237,000298: 23,3413 47414 AXISGEN3
058238,000299:
058239,000300: 23,3414 77704 AXISGEN3 TIX,2
058240,000301: 23,3415 47371 AXISGEN2
058241,000302:
058242,000303: 23,3416 77775 VLOAD
058243,000304: 23,3417 02714 XDC
058244,000305: 23,3420 26736 STOVL STARAD
058245,000306: 23,3421 02722 YDC
058246,000307: 23,3422 26744 STOVL STARAD +6
058247,000308: 23,3423 02730 ZDC
058248,000309: 23,3424 02752 STORE STARAD +12D
058249,000310:
058250,000311: 23,3425 77616 RVQ
058251,000312:
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Page 1331 |
058253,000314: 23,3426 05520 26075 QTSN45 2DEC .1768
058254,000315: 23,3430 05252 25253 .166... 2DEC .1666666667
058255,000316:
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Page 1332 There is no source code on this page of the original assembly listing. —RSB 2004 |
058258,000319:
058259,000320:
End of include-file INFLIGHT_ALIGNMENT_ROUTINES.agc. Parent file is MAIN.agc