### FILE="Main.annotation" ## Copyright: Public domain. ## Filename: GIMBAL_LOCK_AVOIDANCE.agc ## Purpose: A log section of Zerlina 56, the final revision of ## Don Eyles's offline development program for the variable ## guidance period servicer. It also includes a new P66 with LPD ## (Landing Point Designator) capability, based on an idea of John ## Young's. Neither of these advanced features were actually flown, ## but Zerlina was also the birthplace of other big improvements to ## Luminary including the terrain model and new (Luminary 1E) ## analog display programs. Zerlina was branched off of Luminary 145, ## and revision 56 includes all changes up to and including Luminary ## 183. It is therefore quite close to the Apollo 14 program, ## Luminary 178, where not modified with new features. ## Reference: p. 369 ## Assembler: yaYUL ## Contact: Ron Burkey . ## Website: www.ibiblio.org/apollo/index.html ## Mod history: 2017-07-28 MAS Created from Luminary 210. ## 2017-08-22 RSB Transcribed. ## Page 369 BANK 15 SETLOC KALCMON1 BANK # DETECTING GIMBAL LOCK LOCSKIRT EQUALS NOGIMLOC NOGIMLOC SET CALCMAN3 WCALC LXC,1 DLOAD* RATEINDX # CHOOSE THE DESIRED MANEUVER RATE ARATE,1 # FROM A LIST OF FOUR SR4 CALL # COMPUTE THE INCREMENTAL ROTATION MATRIX DELCOMP # DEL CORRESPONDING TO A 1 SEC ROTATION # ABOUT COF DLOAD* VXSC ARATE,1 COF STODL BRATE # COMPONENT MANEUVER RATES 45 DEG/SEC AM DMP DDV* ANGLTIME ARATE,1 SR 5 STORE TM # MANEUVER EXECUTION TIME SCALED AS T2 SETGO CALCMAN2 # 0(OFF) = CONTINUE MANEUVER NEWANGL +1 # 1(ON) = START MANEUVER # THE FOUR SELECTABLE FREE FALL MANEUVER RATES SELECTED BY # LOADING RATEINDX WITH 0,2,4,6, RESPECTIVELY ARATE 2DEC .0088888888 # = 0.2 DEG/SEC $ 22.5 DEG/SEC 2DEC .0222222222 # = 0.5 DEG/SEC $ 22.5 DEG/SEC 2DEC .0888888888 # = 2.0 DEG/SEC $ 22.5 DEG/SEC 2DEC .4444444444 # = 10.0 DEG/SEC $ 22.5 DEG/SEC ANGLTIME 2DEC .0001907349 # = 100B-19 FUDGE FACTOR TO CONVERT # MANEUVER ANGLE TO MANEUVER TIME