Pre-launch Review
TVCMASSPROP
Scanned pages: 951-955
# Copyright: Public domain.# Filename: TVCMASSPROP.agc# Purpose: Part of the source code for Colossus 2A, AKA Comanche 055.# It is part of the source code for the Command Module's (CM)# Apollo Guidance Computer (AGC), for Apollo 11.# Assembler: yaYUL# Contact: Ron Burkey <info@sandroid.org>.# Website: www.ibiblio.org/apollo.# Pages: 951-955# Mod history: 2009-05-13 RSB Adapted from the Colossus249/ file of the# same name, using Comanche055 page images.## This source code has been transcribed or otherwise adapted from digitized# images of a hardcopy from the MIT Museum. The digitization was performed# by Paul Fjeld, and arranged for by Deborah Douglas of the Museum. Many# thanks to both. The images (with suitable reduction in storage size and# consequent reduction in image quality as well) are available online at# www.ibiblio.org/apollo. If for some reason you find that the images are# illegible, contact me at info@sandroid.org about getting access to the# (much) higher-quality images which Paul actually created.## Notations on the hardcopy document read, in part:## Assemble revision 055 of AGC program Comanche by NASA# 2021113-051. 10:28 APR. 1, 1969## This AGC program shall also be referred to as# Colossus 2A
# Page 951# PROGRAM NAME....MASSPROP# LOG SECTION....TVCMASSPROP PROGRAMMER...MELANSON (ENGEL, SCHLUNDT)### FUNCTIONAL DESCRIPTION:## MASSPROP OPERATES IN TWO MODES:(1)IF LEM MASS OR CONFIGURATION ARE UPDATED (MASSPROP DOES NOT TEST# FOR THIS) THE ENTIRE PROGRAM MUST BE RUN THROUGH, BREAKPOINT VALUES AND DERIVATIVES OF THE OUTPUTS WITH# RESPECT TO CSM MASS BEING CALCULATED PRIOR TO CALCULATION OF THE OUTPUTS. (2)OTHERWISE, THE OUTPUTS CAN BE# CALCULATED USING PREVIOUSLY COMPUTED BREAKPOINT VALUES AND DERIVATIVES.## CALLING SEQUENCES## IF LEM MASS OR CONFIGURATION HAS BEEN UPDATED, TRANSFER TO MASSPROP, OTHERWISE TRANSFER TO FIXCW.# L TC BANKCALL OR IBNKCALL# L+1 CADR MASSPROP# OR# L+1 CADR FIXCW## L+2 RETURNS VIA Q## CALLED IN PARTICULAR BY DONOUN47 (JOB) AND TVCEXECUTIVE (TASK)## JOBS OR TASKS INITIATED - NONE## SUBROUTINES CALLED - NONE## ERASABLE INITIALIZATION REQUIRED## LEMMASS MUST CONTAIN LEM MASS SCALED AT B+16 KILOGRAMS# CSMMASS MUST CONTAIN CSM MASS SCALED AT B+16 KILOGRAMS## DAPDATR1 MUST BE SET TO INDICATE VEHICLE CONFIGURATION.# BITS (15,14,13) = ( 0 , 0 , 1 ) LEM OFF# ( 0 , 1 , 0 ) LEM ON (ASCNT,DSCNT)# ( 1 , 1 , 0 ) LEM ON (ASCNT ONLY)### ALARMS - NONE## EXIT - TC Q## OUTPUTS:## (1)IXX, SINGLE PRECISION SCALED AT B+20 IN KG-M SQ.# (2)IAVG, SINGLE PRECISION SCALED AT B+20 IN KG-M SQ.# (3)IAVG/TLX, SINGLE PRECISION, SCALED AT B+2 SEC-SQD# THEY ARE STORED IN CONSECUTIVE REGISTERS IXX0, IXX1, IXX2## CONVERSION FACTOR : (SLUG-FTSQ) = 0.737562 (KG-MSQ)# Page 952## OUTPUTS ARE CALCULATED AS FOLLOWS:## (1) IF LEM DOCKED, LEMMASS IS FIRST ELIMINATED AS A PARAMETER## VARST0 = INTVALUE0 + LEMMASS(SLOPEVAL0) IXX BREAKPOINT VALUE# VARST1 = INTVALUE1 + LEMMASS(SLOPEVAL1) IAVG BREAKPOINT VALUE# VARST2 = INTVALUE2 + LEMMASS(SLOPEVAL2) IAVG/TLX BREAKPOINT VALUE## VARST3 = INTVALUE3 + LEMMASS(SLOPEVAL3) IAVG/TLX SLOPE FOR CSMMASS > 33956 LBS ( SPS > 10000 LBS)# VARST4 = INTVALUE4 + LEMMASS(SLOPEVAL4) IAVG SLOPE FOR CSMMASS > 33956 LBS ( SPS > 10000 LBS)## VARST5 = INTVALUE5 + LEMMASS(SLOPEVAL5) IXX SLOPE FOR ALL VALUES OF CSMMASS## VARST6 = INTVALUE6 + LEMMASS(SLOPEVAL6) IAVG SLOPE FOR CSMMASS < 33956 LBS ( SPS < 10000 LBS)# VARST7 = INTVALUE7 + LEMMASS(SLOPEVAL7) IAVG/TLX SLOPE FOR CSMMASS < 33956 LBS ( SPS < 10000 LBS)## VARST8 = INTVALUE8 + LEMMASS(SLOPEVAL8) IAVG DECREMENT TO BRKPT VALUE WHEN LEM DSCNT STAGE OFF# VARST9 = INTVALUE9 + LEMMASS(SLOPEVAL9) IAVG/TLX DECREMENT TO BRKPT VALUE WHEN LEM DSCNT STAGE OFF## (2) IF LEM NOT DOCKED## VARST0 = NOLEMVAL0 WHERE THE MEANING AND SCALING OF VARST0# . . TO VARST9 ARE THE SAME AS GIVEN ABOVE# . .# . . NOTE... FOR THIS CASE, VARST8,9 HAVE NO# VARST9 = NOLEMVAL9 MEANING (THEY ARE COMPUTED BUT NOT USED)## (3) THE FINAL OUTPUT CALCULATIONS ARE THEN DONE## IXX0 = VARST0 + (CSMMASS + NEGBPW)VARST5 IXX## IXX1 = VARST1 + (CSMMASS + NEGBPW)VARST(4 OR 6) IAVG## IXX2 = VARST2 + (CSMMASS + NEGBPW)VARST(3 OR 7) IAVG/TLX### THE DATA USED CAME FROM CSM/LM SPACECRAFT OPERATIONAL DATA BOOK.# VOL. 3, NASA DOCUMENT SNA-8-D-027 (MARCH 1968)## PERTINENT MASS DATA : CSM WEIGHT (FULL) 64100 LBS.# (EMPTY) 23956 LBS.# LEM WEIGHT (FULL) 32000 LBS.# (EMPTY) 14116 LBS.## (WEIGHTS ARE FROM AMENDMENT #1 (APRIL 24,1968) TO ABOVE DATA BOOK)# Page 953
BANK 25 SETLOC DAPMASS BANK EBANK= BZERO COUNT* $$/MASP
MASSPROP CAF NINE # MASSPROP USES TVC/RCS INTERRUPT TEMPS TS PHI333 # SET UP TEN PASSES
LEMTEST CAE DAPDATR1 # DETERMINE LEM STATUS MASK BIT13 EXTEND BZF LEMYES
LEMNO INDEX PHI333 # LEM NOT ATTACHED CAF NOLEMVAL TCF STOINST
LEMYES CAE LEMMASS # LEM IS ATTACHED DOUBLE EXTEND INDEX PHI333 MP SLOPEVAL DDOUBL INDEX PHI333 AD INTVALUE
STOINST INDEX PHI333 # STORAGE INST BEGIN HERE TS VARST0 CCS PHI333 # ARE ALL TEN PASSES COMPLETED TCF MASSPROP +1 # NO - GO DECREMENT PHI333
DXTEST CCS DAPDATR1 # IF NEG, BIT15 IS 1, LEM DSCNT STAGE OFF TCF FIXCW TCF FIXCW DXCH VARST0 +8D DAS VARST0 +1 CA DXITFIX ADS VARST0 +7
FIXCW CAF BIT2 # COMPUTATION PHASE BEGINS HERE. SET UP TS PHI333 # THREE PASSES TS PSI333
CAE CSMMASS # GET DELTA CSM WEIGHT - SIGN DETERMINES AD NEGBPW # SLOPE LOCATIONS. DOUBLE TS TEMP333# Page 954 EXTEND BZMF PEGGY # DETERMINE CORRECT SLOPE CAF NEG2 TS PHI333
PEGGY INDEX PHI333 # ALL IS READY - CALCULATE OUTPUTS NOW CAE VARST5 # GET SLOPE EXTEND MP TEMP333 # MULT BY DELTA CSM WEIGHT DOUBLE INDEX PSI333 AD VARST0 # ADD BREAKPOINT VALUE INDEX PSI333 TS IXX # ****** OUTPUTS (IXX0, IXX1, IXX2) ******
CCS PSI333 # BOOKKEEPING - MASSPROP FINISHED OR NOT TCF BOKKEP2 # NO - GO TAKE CARE OF INDEXING REGISTERS
CAE DAPDATR1 # UPDATE WEIGHT/G MASK BIT14 CCS A CA LEMMASS AD CSMMASS TS WEIGHT/G # SCALED AT B+16 KILOGRAMSENDMASSP TC Q
BOKKEP2 TS PSI333 # REDUCE PSI BY ONE EXTEND DIM PHI333 TCF PEGGY
# Page 955NOLEMVAL DEC 25445 B-20 DEC 87450 B-20 DEC .30715 B-2 DEC 1.22877 E-5 B+12 DEC 1.6096 B-6 DEC 1.54 B-6 DEC 7.77177 B-6 DEC 3.46458 E-5 B+12
INTVALUE DEC 26850 B-20 DEC 127518 B-20 DEC .54059 B-2 DEC .153964 E-4 B+12 DEC -.742923 B-6 DEC 1.5398 B-6 DEC 9.68 B-6 DEC .647625 E-4 B+12 DEC -27228 B-20 DEC -.206476 B-2
SLOPEVAL DEC 1.96307 B-6 DEC 27.5774 B-6 DEC 2.3548 E-5 B+12 DEC 2.1777 E-9 B+26 DEC 1.044 E-3 B+8 DEC 0 DEC 2.21068 E-3 B+8 DEC 1.5166 E-9 B+26 DEC -1.284 B-6 DEC 2 E-5 B+12
NEGBPW DEC -15402.17 B-16DXITFIX DEC* -1.88275 E-5 B+12*