Source Code
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These source-code files were derived from scans of the
Colossus 237 (Apollo 8 Command Module) program listing from the private collection of original
AGC developer Fred Martin. Scanning was by Ron Burkey. Pre-existing Colossus 249
(Apollo 9 CM) source files were used as a template, and changes between Colossus 249
and Colossus 237 were manually transcribed by a team of volunteers. Note
that the page images
presented online are of reduced quality, and that additional 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:GAP: ASSEMBLE REVISION 237 OF AGC PROGRAM COLOSSUS BY NASA 2021111-031 1:17 AUG. 24, 1968Note that the date is the date of the printout, not the date of the program revision. |
056192,000002: ## Copyright: Public domain.
056193,000003: ## Filename: INFLIGHT_ALIGNMENT_ROUTINES.agc
056194,000004: ## Purpose: Part of the source code for Colossus build 237.
056195,000005: ## This is for the Command Module's (CM) Apollo Guidance
056196,000006: ## Computer (AGC), for Apollo 8.
056197,000007: ## Assembler: yaYUL
056198,000008: ## Contact: Jim Lawton <jim DOT lawton AT gmail DOT com>
056199,000009: ## Website: www.ibiblio.org/apollo/index.html
056200,000010: ## Page Scans: www.ibiblio.org/apollo/ScansForConversion/Colossus237/
056201,000011: ## Mod history: 2011-04-17 JL Adapted from corresponding Colossus 249 file.
056202,000012: ## 2017-01-01 RSB Proofed comment text using octopus/ProoferComments,
056203,000013: ## and fixed errors found.
056204,000014:
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Page 1319 |
056206,000016: 22,3505 BANK 22
056207,000017: 23,2000 SETLOC INFLIGHT
056208,000018: 23,2000 BANK
056209,000019:
056210,000020: 23,3140 E5,1671 EBANK= XSM
056211,000021:
056212,000022:
056213,000023: # CALCGTA COMPUTES THE GYRO TORQUE ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
056214,000024:
056215,000025: # THE INPUT IS THE DESIRED STABLE MEMBER COORDINATES REFERRED TO PRESENT STABLE MEMBER COORDINATES. THE THREE
056216,000026: # HALF-UNIT VECTORS ARE STORED AT XDC, YDC, AND ZDC.
056217,000027:
056218,000028: # THE OUTPUTS ARE THE THREE GYRO TORQUING ANGLES TO BE APPLIED TO THE Y, Z, AND X GYROS AND ARE STORED DP AT IGC,
056219,000029: # MGC, AND OGC RESPECTIVELY.
056220,000030:
056221,000031: 23,3140 COUNT 23/INFLT
056222,000032:
056223,000033: 23,3140 71220 CALCGTA ITA DLOAD # PUSHDOWN 00-03,16D-27D,34D-37D
056224,000034: 23,3141 00051 S2 # XDC = (XD1 XD2 XD3)
056225,000035: 23,3142 02714 XDC # YDC = (YD1 YD2 YD3)
056226,000036: 23,3143 65325 PDDL PDDL # ZDC = (ZD1 ZD2 ZD3)
056227,000037: 23,3144 15332 HI6ZEROS
056228,000038: 23,3145 02720 XDC +4
056229,000039: 23,3146 55476 DCOMP VDEF
056230,000040: 23,3147 77656 UNIT
056231,000041: 23,3150 14027 STODL ZPRIME # ZP = UNIT(-XD3 0 XD1) = (ZP1 ZP2 ZP3)
056232,000042: 23,3151 00027 ZPRIME
056233,000043:
056234,000044: 23,3152 77742 SR1
056235,000045: 23,3153 14023 STODL SINTH # SIN(IGC) = ZP1
056236,000046: 23,3154 00033 ZPRIME +4
056237,000047: 23,3155 77742 SR1
056238,000048: 23,3156 34021 STCALL COSTH # COS(IGC) = ZP3
056239,000049: 23,3157 47211 ARCTRIG
056240,000050:
056241,000051: 23,3160 16762 STODL IGC # Y GYRO TORQUING ANGLE FRACTION OF REV.
056242,000052: 23,3161 02716 XDC +2
056243,000053: 23,3162 77742 SR1
056244,000054: 23,3163 14023 STODL SINTH # SIN(MGC) = XD2
056245,000055: 23,3164 00027 ZPRIME
056246,000056:
056247,000057: 23,3165 65205 DMP PDDL
056248,000058: 23,3166 02720 XDC +4 # PD00 = (ZP1)(XD3)
056249,000059: 23,3167 00033 ZPRIME +4
056250,000060:
056251,000061: 23,3170 45205 DMP DSU
056252,000062: 23,3171 02714 XDC # MPAC = (ZP3)(XD1)
056253,000063: 23,3172 77626 STADR
056254,000064: 23,3173 43756 STCALL COSTH # COS(MGC) = MPAC - PD00
056255,000065: 23,3174 47211 ARCTRIG
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Page 1320 |
056257,000067: 23,3175 26764 STOVL MGC # Z GYRO TORQUING ANGLE FRACTION OF REV.
056258,000068: 23,3176 00027 ZPRIME
056259,000069: 23,3177 77641 DOT
056260,000070: 23,3200 02730 ZDC
056261,000071: 23,3201 24021 STOVL COSTH # COS(OGC) = ZP . ZDC
056262,000072: 23,3202 00027 ZPRIME
056263,000073: 23,3203 77641 DOT
056264,000074: 23,3204 02722 YDC
056265,000075: 23,3205 34023 STCALL SINTH # SIN(OGC) = ZP . YDC
056266,000076: 23,3206 47211 ARCTRIG
056267,000077:
056268,000078: 23,3207 36760 STCALL OGC # X GYRO TORQUING ANGLE FRACTION OF REV.
056269,000079: 23,3210 00051 S2
056270,000080:
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Page 1321 |
056272,000082: # ARCTRIG COMPUTES AN ANGLE GIVEN THE SINE AND COSINE OF THIS ANGLE.
056273,000083:
056274,000084: # THE INPUTS ARE SIN/4 AND COS/4 STORED DP AT SINTH AND COSTH.
056275,000085:
056276,000086: # THE OUTPUT IS THE CALCULATED ANGLE BETWEEN +.5 AND -.5 REVOLUTIONS AND STORED AT THETA. THE OUTPUT IS ALSO
056277,000087: # AVAILABLE AT MPAC.
056278,000088:
056279,000089:
056280,000090: 23,3211 51545 ARCTRIG DLOAD ABS # PUSHDOWN 16D-21D
056281,000091: 23,3212 00023 SINTH
056282,000092: 23,3213 50025 DSU BMN
056283,000093: 23,3214 07427 QTSN45 # ABS(SIN/4) - SIN(45)/4
056284,000094: 23,3215 47224 TRIG1 # IF (-45,45) OR (135,-135)
056285,000095:
056286,000096:
056287,000097: 23,3216 72545 DLOAD SL1 # (45,135) OR (-135,-45)
056288,000098: 23,3217 00021 COSTH
056289,000099: 23,3220 75326 ACOS SIGN
056290,000100: 23,3221 00023 SINTH
056291,000101: 23,3222 00025 STORE THETA # X = ARCCOS(COS) WITH SIGN(SIN)
056292,000102: 23,3223 77616 RVQ
056293,000103:
056294,000104:
056295,000105: 23,3224 72545 TRIG1 DLOAD SL1 # (-45,45) OR (135,-135)
056296,000106: 23,3225 00023 SINTH
056297,000107: 23,3226 77736 ASIN
056298,000108: 23,3227 14025 STODL THETA # X = ARCSIN(SIN) WITH SIGN(SIN)
056299,000109: 23,3230 00021 COSTH
056300,000110: 23,3231 77640 BMN
056301,000111: 23,3232 47235 TRIG2 # IF (135,-135)
056302,000112:
056303,000113: 23,3233 43545 DLOAD RVQ
056304,000114: 23,3234 00025 THETA # X = ARCSIN(SIN) (-45,45)
056305,000115:
056306,000116:
056307,000117: 23,3235 75345 TRIG2 DLOAD SIGN # (135,-135)
056308,000118: 23,3236 15330 HIDPHALF
056309,000119: 23,3237 00023 SINTH
056310,000120: 23,3240 77625 DSU
056311,000121: 23,3241 00025 THETA
056312,000122: 23,3242 00025 STORE THETA # X = .5 WITH SIGN(SIN) - ARCSIN(SIN)
056313,000123: 23,3243 77616 RVQ # (+) - (+) OR (-) - (-)
056314,000124:
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Page 1322 |
056316,000126: # SMNB, NBSM, AND AXISROT, WHICH USED TO APPEAR HERE, HAVE BEEN
056317,000127: # COMBINED IN A ROUTINE CALLED AX*SR*T, WHICH APPEARS AMONG THE POWERED
056318,000128: # FLIGHT SUBROUTINES.
056319,000129:
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Page 1323 |
056321,000131: # CALCGA COMPUTES THE CDU DRIVING ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
056322,000132:
056323,000133: # THE INPUTS ARE 1) THE NAVIGATION BASE COORDINATES REFERRED TO ANY COORDINATE SYSTEM. THE THREE HALF-UNIT
056324,000134: # VECTORS ARE STORED AT XNB,YNB, AND ZNB. 2) THE DESIRED STABLE MEMBER COORDINATES REFERRED TO THE SAME
056325,000135: # COORDINATE SYSTEM ARE STORED AT XSM, YSM, AND ZSM.
056326,000136:
056327,000137: # THE OUTPUTS ARE THE THREE CDU DRIVING ANGLES AND ARE STORED SP AT THETAD, THETAD +1, AND THETAD +2.
056328,000138:
056329,000139: 23,3244 77601 CALCGA SETPD # PUSHDOWN 00-05, 16D-21D, 34D-37D
056330,000140: 23,3245 00001 0
056331,000141: 23,3246 47375 VLOAD VXV
056332,000142: 23,3247 02714 XNB # XNB = OGA (OUTER GIMBAL AXIS)
056333,000143: 23,3250 02700 YSM # YSM = IGA (INNER GIMBAL AXIS)
056334,000144: 23,3251 41456 UNIT PUSH # PD0 = UNIT(OGA X IGA) = MGA
056335,000145:
056336,000146: 23,3252 44041 DOT ITA
056337,000147: 23,3253 02730 ZNB
056338,000148: 23,3254 00051 S2
056339,000149: 23,3255 24021 STOVL COSTH # COS(OG) = MGA . ZNB
056340,000150: 23,3256 00001 0
056341,000151: 23,3257 77641 DOT
056342,000152: 23,3260 02722 YNB
056343,000153: 23,3261 34023 STCALL SINTH # SIN(OG) = MGA . YNB
056344,000154: 23,3262 47211 ARCTRIG
056345,000155: 23,3263 26760 STOVL OGC
056346,000156: 23,3264 00001 0
056347,000157:
056348,000158: 23,3265 50235 VXV DOT # PROVISION FOR MG ANGLE OF 90 DEGREES
056349,000159: 23,3266 02714 XNB
056350,000160: 23,3267 02700 YSM
056351,000161: 23,3270 77752 SL1
056352,000162: 23,3271 24021 STOVL COSTH # COS(MG) = IGA . (MGA X OGA)
056353,000163: 23,3272 02700 YSM
056354,000164: 23,3273 77641 DOT
056355,000165: 23,3274 02714 XNB
056356,000166: 23,3275 34023 STCALL SINTH # SIN(MG) = IGA . OGA
056357,000167: 23,3276 47211 ARCTRIG
056358,000168: 23,3277 02764 STORE MGC
056359,000169:
056360,000170: 23,3300 45246 ABS DSU
056361,000171: 23,3301 07431 .166...
056362,000172: 23,3302 77644 BPL
056363,000173: 23,3303 47324 GIMLOCK1 # IF ANGLE GREATER THAN 60 DEGREES
056364,000174:
056365,000175: 23,3304 50375 CALCGA1 VLOAD DOT
056366,000176: 23,3305 02706 ZSM
056367,000177: 23,3306 00001 0
056368,000178: 23,3307 24021 STOVL COSTH # COS(IG) = ZSM . MGA
056369,000179: 23,3310 02672 XSM
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Page 1324 |
056371,000181: 23,3311 45441 DOT STADR
056372,000182: 23,3312 43754 STCALL SINTH # SIN(IG) = XSM . MGA
056373,000183: 23,3313 47211 ARCTRIG
056374,000184:
056375,000185: 23,3314 26762 STOVL IGC
056376,000186: 23,3315 02760 OGC
056377,000187: 23,3316 43034 RTB BONCLR
056378,000188: 23,3317 45547 V1STO2S
056379,000189: 23,3320 00200 CPHIFLAG
056380,000190: 23,3321 00051 S2
056381,000191: 23,3322 35156 STCALL THETAD
056382,000192: 23,3323 00051 S2
056383,000193:
056384,000194: 23,3324 77776 GIMLOCK1 EXIT
056385,000195: 23,3325 05537 TC ALARM
056386,000196: 23,3326 00401 OCT 00401
056387,000197: 23,3327 05435 TC UPFLAG # GIMBAL LOCK HAS OCCURED
056388,000198: 23,3330 00056 ADRES GLOKFAIL
056389,000199:
056390,000200: 23,3331 06006 TC INTPRET
056391,000201: 23,3332 77650 GOTO
056392,000202: 23,3333 47304 CALCGA1
056393,000203:
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Page 1325 |
056395,000205: # AXISGEN COMPUTES THE COORDINATES OF ONE COORDINATE SYSTEM REFERRED TO ANOTHER COORDINATE SYSTEM.
056396,000206:
056397,000207: # THE INPUTS ARE 1) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM A STORED AT STARAD. 2) THE STAR2 VECTOR
056398,000208: # REFERRED TO COORDINATE SYSTEM A STORED AT STARAD +6. 3) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM B STORED
056399,000209: # AT LOCATION 6 OF THE VAC AREA. 4) THE STAR2 VECTOR REFERRED TO COORDINATE SYSTEM B STORED AT LOCATION 12D OF
056400,000210: # THE VAC AREA.
056401,000211:
056402,000212: # THE OUTPUT DEFINES COORDINATE SYSTEM A REFERRED TO COORDINATE SYSTEM B. THE THREE HALF-UNIT VECTORS ARE STORED
056403,000213: # AT LOCATIONS XDC, XDC +6, XDC +12D, AND STARAD, STARAD +6, STARAD +12D.
056404,000214:
056405,000215:
056406,000216: 23,3334 66370 AXISGEN AXT,1 SSP # PUSHDOWN 00-30D,34D-37D
056407,000217: 23,3335 02743 STARAD +6
056408,000218: 23,3336 00051 S1
056409,000219: 23,3337 02727 STARAD -6
056410,000220:
056411,000221: 23,3340 77601 SETPD
056412,000222: 23,3341 00001 0
056413,000223: 23,3342 46773 AXISGEN1 VLOAD* VXV* # 06D UA = S1
056414,000224: 23,3343 02752 STARAD +12D,1 # STARAD +00D UB = S1
056415,000225: 23,3344 02760 STARAD +18D,1
056416,000226: 23,3345 77656 UNIT # 12D VA = UNIT(S1 X S2)
056417,000227: 23,3346 06760 STORE STARAD +18D,1 # STARAD +06D VB = UNIT(S1 X S2)
056418,000228: 23,3347 77773 VLOAD*
056419,000229: 23,3350 02752 STARAD +12D,1
056420,000230:
056421,000231: 23,3351 76433 VXV* VSL1
056422,000232: 23,3352 02760 STARAD +18D,1 # 18D WA = UA X VA
056423,000233: 23,3353 06766 STORE STARAD +24D,1 # STARAD +12D WB = UB X VB
056424,000234:
056425,000235: 23,3354 77700 TIX,1
056426,000236: 23,3355 47342 AXISGEN1
056427,000237:
056428,000238: 23,3356 66160 AXC,1 SXA,1
056429,000239: 23,3357 00006 6
056430,000240: 23,3360 00036 30D
056431,000241:
056432,000242: 23,3361 66370 AXT,1 SSP
056433,000243: 23,3362 00022 18D
056434,000244: 23,3363 00051 S1
056435,000245: 23,3364 00006 6
056436,000246:
056437,000247: 23,3365 66374 AXT,2 SSP
056438,000248: 23,3366 00006 6
056439,000249: 23,3367 00052 S2
056440,000250: 23,3370 00002 2
056441,000251:
056442,000252: 23,3371 76720 AXISGEN2 XCHX,1 VLOAD*
056443,000253: 23,3372 00036 30D # X1=-6 X2=+6 X1=-6 X2=+4 X1=-6 X2=+2
056444,000254: 23,3373 00001 0,1
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Page 1326 |
056446,000256: 23,3374 62757 VXSC* PDVL* # J=(UA)(UB1) J=(UA)(UB2) J=(UA)(UB3)
056447,000257: 23,3375 75033 STARAD +6,2
056448,000258: 23,3376 00007 6,1
056449,000259: 23,3377 77757 VXSC*
056450,000260: 23,3400 75025 STARAD +12D,2
056451,000261: 23,3401 30031 STOVL* 24D # K=(VA)(VB1) J=(VA)(VB2) J=(VA)(VB3)
056452,000262: 23,3402 00015 12D,1
056453,000263:
056454,000264: 23,3403 53357 VXSC* VAD
056455,000265: 23,3404 75017 STARAD +18D,2 # L=(WA)(WB1) J=(WA)(WB2) J=(WA)(WB3)
056456,000266: 23,3405 76455 VAD VSL1
056457,000267: 23,3406 00031 24D
056458,000268: 23,3407 53520 XCHX,1 UNIT
056459,000269: 23,3410 00036 30D
056460,000270: 23,3411 06736 STORE XDC +18D,1 # XDC = L+J+K YDC = L+J+K ZDC = L+J+K
056461,000271:
056462,000272: 23,3412 77700 TIX,1
056463,000273: 23,3413 47414 AXISGEN3
056464,000274:
056465,000275: 23,3414 77704 AXISGEN3 TIX,2
056466,000276: 23,3415 47371 AXISGEN2
056467,000277:
056468,000278: 23,3416 77775 VLOAD
056469,000279: 23,3417 02714 XDC
056470,000280: 23,3420 26736 STOVL STARAD
056471,000281: 23,3421 02722 YDC
056472,000282: 23,3422 26744 STOVL STARAD +6
056473,000283: 23,3423 02730 ZDC
056474,000284: 23,3424 02752 STORE STARAD +12D
056475,000285:
056476,000286: 23,3425 77616 RVQ
056477,000287:
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Page 1327 |
056479,000289: 23,3426 05520 26075 QTSN45 2DEC .1768
056480,000290: 23,3430 05252 25253 .166... 2DEC .1666666667
056481,000291:
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Page 1328 Empty page. |
End of include-file INFLIGHT_ALIGNMENT_ROUTINES.agc. Parent file is MAIN.agc