100 lines
2.1 KiB
ArmAsm
100 lines
2.1 KiB
ArmAsm
# Copyright: Public domain.
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# Filename: GIMBAL_LOCK_AVOIDANCE.agc
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# Purpose: Part of the source code for Comanche, build 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), Apollo 11.
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# Assembler: yaYUL
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# Reference: pp. 412-413
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# Contact: Onno Hommes <ohommes@cmu.edu>.
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# Website: www.ibiblio.org/apollo.
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# Mod history: 05/07/09 OH Transcription Batch 1 Assignment
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#
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# The contents of the "Comanche055" files, in general, are transcribed
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# from scanned documents.
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#
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# Assemble revision 055 of AGC program Comanche by NASA
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# 2021113-051. April 1, 1969.
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#
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# This AGC program shall also be referred to as Colossus 2A
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#
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# Prepared by
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# Massachusetts Institute of Technology
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# 75 Cambridge Parkway
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# Cambridge, Massachusetts
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#
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# under NASA contract NAS 9-4065.
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#
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# Refer directly to the online document mentioned above for further information.
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# Please report any errors to info@sandroid.org.
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# Page 412
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BANK 15
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SETLOC KALCMON1
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BANK
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EBANK= BCDU
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# DETECTING GIMBAL LOCK
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LOCSKIRT EQUALS WCALC
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WCALC LXC,1 DLOAD*
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RATEINDX
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ARATE,1
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SR4 CALL # COMPUTE THE INCREMENTAL ROTATION MATRIX
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DELCOMP # DEL CORRESPONDING TO A 1 SEC ROTATION
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# ABOUT COF
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DLOAD* VXSC
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ARATE,1
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COF
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MXV
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QUADROT
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STODL BRATE
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AM
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DMP DDV*
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ANGLTIME
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ARATE,1
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SR
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5
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STOVL TM
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BRATE
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VXSC
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BIASCALE
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STORE BIASTEMP # ATTITUDE ERROR BIAS TO PREVENT OVERSHOOT
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# IN SYSTEM
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SETGO # STATE SWITCH CALCMAN2 (43D)
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CALCMAN2 # 0(OFF) = BYPASS STARTING PROCEDURE
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NEWANGL +1 # 1(ON) = START MANEUVER
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ARATE 2DEC .0022222222 # = .05 DEG/SEC
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2DEC .0088888889 # = .2 DEG/SEC
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2DEC .0222222222 # = .5 DEG/SEC
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2DEC .0888888889 # = 2 DEG/SEC $22.5 DEG/SEC
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ANGLTIME 2DEC .000190735 # = 100B - 19
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# MANEUVER ANGLE TO MANEUVER TIME
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QUADROT 2DEC .1 # ROTATION MATRIX FROM S/C AXES TO CONTROL
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# Page 413
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2DEC 0 # AXES (X ROT = -7.25 DEG)
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2DEC 0
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2DEC 0
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2DEC .099200 # =(.1)COS7.25
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2DEC -.012620 # =-(.1)SIN7.25
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2DEC 0
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2DEC .012620 # (.1)SIN7.25
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2DEC .099200 # (.1)COS7.25
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BIASCALE 2DEC .0002543132 # = (450/180)(1/0.6)(1/16384)
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