305 lines
6.9 KiB
Plaintext
305 lines
6.9 KiB
Plaintext
# Copyright: Public domain.
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# Filename: INFLIGHT_ALIGNMENT_ROUTINES.agc
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# Purpose: Part of the source code for Colossus 2A, AKA Comanche 055.
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# It is part of the source code for the Command Module's (CM)
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# Apollo Guidance Computer (AGC), for Apollo 11.
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# Assembler: yaYUL
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# Contact: Ron Burkey <info@sandroid.org>.
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# Website: www.ibiblio.org/apollo.
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# Pages: 1355-1364
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# Mod history: 2009-05-14 RSB Adapted from the Colossus249/ file of the
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# same name, using Comanche055 page images.
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#
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# This source code has been transcribed or otherwise adapted from digitized
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# images of a hardcopy from the MIT Museum. The digitization was performed
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# by Paul Fjeld, and arranged for by Deborah Douglas of the Museum. Many
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# thanks to both. The images (with suitable reduction in storage size and
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# consequent reduction in image quality as well) are available online at
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# www.ibiblio.org/apollo. If for some reason you find that the images are
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# illegible, contact me at info@sandroid.org about getting access to the
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# (much) higher-quality images which Paul actually created.
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#
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# Notations on the hardcopy document read, in part:
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#
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# Assemble revision 055 of AGC program Comanche by NASA
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# 2021113-051. 10:28 APR. 1, 1969
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#
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# This AGC program shall also be referred to as
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# Colossus 2A
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# Page 1355
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BANK 22
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SETLOC INFLIGHT
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BANK
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EBANK= XSM
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# CALCGTA COMPUTES THE GYRO TORQUE ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
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#
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# THE INPUT IS THE DESIRED STABLE MEMBER COORDINATES REFERRED TO PRESENT STABLE MEMBER COORDINATES. THE THREE
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# HALF-UNIT VECTORS ARE STORED AT XDC, YDC, AND ZDC.
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#
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# THE OUTPUTS ARE THE THREE GYRO TORQUING ANGLES TO BE APPLIED TO THE Y, Z, AND X GYROS AND ARE STORED DP AT IGC,
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# MGC, AND OGC RESPECTIVELY.
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COUNT 23/INFLT
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CALCGTA ITA DLOAD # PUSHDOWN 00-03,16D-27D,34D-37D
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S2 # XDC = (XD1 XD2 XD3)
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XDC # YDC = (YD1 YD2 YD3)
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PDDL PDDL # ZDC = (ZD1 ZD2 ZD3)
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HI6ZEROS
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XDC +4
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DCOMP VDEF
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UNIT
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STODL ZPRIME # ZP = UNIT(-XD3 0 XD1) = (ZP1 ZP2 ZP3)
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ZPRIME
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SR1
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STODL SINTH # SIN(IGC) = ZP1
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ZPRIME +4
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SR1
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STCALL COSTH # COS(IGC) = ZP3
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ARCTRIG
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STODL IGC # Y GYRO TORQUING ANGLE FRACTION OF REV.
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XDC +2
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SR1
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STODL SINTH # SIN(MGC) = XD2
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ZPRIME
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DMP PDDL
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XDC +4 # PD00 = (ZP1)(XD3)
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ZPRIME +4
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DMP DSU
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XDC # MPAC = (ZP3)(XD1)
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STADR
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STCALL COSTH # COS(MGC) = MPAC - PD00
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ARCTRIG
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# Page 1356
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STOVL MGC # Z GYRO TORQUING ANGLE FRACTION OF REV.
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ZPRIME
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DOT
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ZDC
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STOVL COSTH # COS(OGC) = ZP . ZDC
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ZPRIME
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DOT
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YDC
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STCALL SINTH # SIN(OGC) = ZP . YDC
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ARCTRIG
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STCALL OGC # X GYRO TORQUING ANGLE FRACTION OF REV.
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S2
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# Page 1357
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# ARCTRIG COMPUTES AN ANGLE GIVEN THE SINE AND COSINE OF THIS ANGLE.
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#
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# THE INPUTS ARE SIN/4 AND COS/4 STORED DP AT SINTH AND COSTH.
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#
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# THE OUTPUT IS THE CALCULATED ANGLE BETWEEN +.5 AND -.5 REVOLUTIONS AND STORED AT THETA. THE OUTPUT IS ALSO
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# AVAILABLE AT MPAC.
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ARCTRIG DLOAD ABS # PUSHDOWN 16D-21D
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SINTH
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DSU BMN
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QTSN45 # ABS(SIN/4) - SIN(45)/4
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TRIG1 # IF (-45,45) OR (135,-135)
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DLOAD SL1 # (45,135) OR (-135,-45)
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COSTH
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ACOS SIGN
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SINTH
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STORE THETA # X = ARCCOS(COS) WITH SIGN(SIN)
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RVQ
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TRIG1 DLOAD SL1 # (-45,45) OR (135,-135)
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SINTH
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ASIN
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STODL THETA # X = ARCSIN(SIN) WITH SIGN(SIN)
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COSTH
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BMN
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TRIG2 # IF (135,-135)
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DLOAD RVQ
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THETA # X = ARCSIN(SIN) (-45,45)
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TRIG2 DLOAD SIGN # (135,-135)
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HIDPHALF
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SINTH
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DSU
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THETA
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STORE THETA # X = .5 WITH SIGN(SIN) - ARCSIN(SIN)
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RVQ # (+) - (+) OR (-) - (-)
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# Page 1358
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# SMNB, NBSM, AND AXISROT, WHICH USED TO APPEAR HERE, HAVE BEEN
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# COMBINED IN A ROUTINE CALLED AX*SR*T, WHICH APPEARS AMONG THE POWERED
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# FLIGHT SUBROUTINES.
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# Page 1359
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# CALCGA COMPUTES THE CDU DRIVING ANGLES REQUIRED TO BRING THE STABLE MEMBER INTO THE DESIRED ORIENTATION.
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#
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# THE INPUTS ARE 1) THE NAVIGATION BASE COORDINATES REFERRED TO ANY COORDINATE SYSTEM. THE THREE HALF-UNIT
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# VECTORS ARE STORED AT XNB, YNB, AND ZNB. 2) THE DESIRED STABLE MEMBER COORDINATES REFERRED TO THE SAME
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# COORDINATE SYSTEM ARE STORED AT XSM, YSM, AND ZSM.
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#
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# THE OUTPUTS ARE THE THREE CDU DRIVING ANGLES AND ARE STORED SP AT THETAD, THETAD +1, AND THETAD +2.
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CALCGA SETPD # PUSHDOWN 00-05, 16D-21D, 34D-37D
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0
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VLOAD VXV
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XNB # XNB = OGA (OUTER GIMBAL AXIS)
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YSM # YSM = IGA (INNER GIMBAL AXIS)
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UNIT PUSH # PD0 = UNIT(OGA X IGA) = MGA
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DOT ITA
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ZNB
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S2
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STOVL COSTH # COS(OG) = MGA . ZNB
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0
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DOT
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YNB
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STCALL SINTH # SIN(OG) = MGA . YNB
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ARCTRIG
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STOVL OGC
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0
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VXV DOT # PROVISION FOR MG ANGLE OF 90 DEGREES
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XNB
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YSM
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SL1
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STOVL COSTH # COS(MG) = IGA . (MGA X OGA)
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YSM
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DOT
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XNB
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STCALL SINTH # SIN(MG) = IGA . OGA
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ARCTRIG
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STORE MGC
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ABS DSU
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.166...
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BPL
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GIMLOCK1 # IF ANGLE GREATER THAN 60 DEGREES
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CALCGA1 VLOAD DOT
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ZSM
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0
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STOVL COSTH # COS(IG) = ZSM . MGA
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XSM
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# Page 1360
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DOT STADR
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STCALL SINTH # SIN(IG) = XSM . MGA
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ARCTRIG
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STOVL IGC
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OGC
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RTB BONCLR
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V1STO2S
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CPHIFLAG
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S2
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STCALL THETAD
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S2
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GIMLOCK1 EXIT
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TC ALARM
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OCT 00401
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TC UPFLAG # GIMBAL LOCK HAS OCCURRED
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ADRES GLOKFAIL
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TC INTPRET
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GOTO
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CALCGA1
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# Page 1361
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# AXISGEN COMPUTES THE COORDINATES OF ONE COORDINATE SYSTEM REFERRED TO ANOTHER COORDINATE SYSTEM.
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#
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# THE INPUTS ARE 1) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM A STORED AT STARAD. 2) THE STAR2 VECTOR
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# REFERRED TO COORDINATE SYSTEM A STORED AT STARAD +6. 3) THE STAR1 VECTOR REFERRED TO COORDINATE SYSTEM B STORED
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# AT LOCATION 6 OF THE VAC AREA. 4) THE STAR2 VECTOR REFERRED TO COORDINATE SYSTEM B STORED AT LOCATION 12D OF
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# THE VAC AREA.
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#
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# THE OUTPUT DEFINES COORDINATE SYSTEM A REFERRED TO COORDINATE SYSTEM B. THE THREE HALF-UNIT VECTORS ARE STORED
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# AT LOCATIONS XDC, XDC +6, XDC +12D, AND STARAD, STARAD +6, STARAD +12D.
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AXISGEN AXT,1 SSP # PUSHDOWN 00-30D, 34D-37D
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STARAD +6
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S1
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STARAD -6
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SETPD
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0
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AXISGEN1 VLOAD* VXV* # 06D UA = S1
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STARAD +12D,1 # STARAD +00D UB = S1
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STARAD +18D,1
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UNIT # 12D VA = UNIT(S1 X S2)
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STORE STARAD +18D,1 # STARAD +06D VB = UNIT(S1 X S2)
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VLOAD*
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STARAD +12D,1
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VXV* VSL1
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STARAD +18D,1 # 18D WA = UA X VA
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STORE STARAD +24D,1 # STARAD +12D WB = UB X VB
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TIX,1
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AXISGEN1
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AXC,1 SXA,1
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6
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30D
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AXT,1 SSP
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18D
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S1
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6
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AXT,2 SSP
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6
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S2
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2
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AXISGEN2 XCHX,1 VLOAD*
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30D # X1=-6 X2=+6 X1=-6 X2=+4 X1=-6 X2=+2
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0,1
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# Page 1362
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VXSC* PDVL* # J=(UA)(UB1) J=(UA)(UB2) J=(UA)(UB3)
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STARAD +6,2
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6,1
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VXSC*
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STARAD +12D,2
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STOVL* 24D # K=(VA)(VB1) J=(VA)(VB2) J=(VA)(VB3)
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12D,1
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VXSC* VAD
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STARAD +18D,2 # L=(WA)(WB1) J=(WA)(WB2) J=(WA)(WB3)
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VAD VSL1
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24D
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XCHX,1 UNIT
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30D
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STORE XDC +18D,1 # XDC = L+J+K YDC = L+J+K ZDC = L+J+K
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TIX,1
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AXISGEN3
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AXISGEN3 TIX,2
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AXISGEN2
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VLOAD
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XDC
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STOVL STARAD
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YDC
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STOVL STARAD +6
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ZDC
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STORE STARAD +12D
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RVQ
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# Page 1363
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QTSN45 2DEC .1768
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.166... 2DEC .1666666667
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# Page 1364 (empty page)
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