Source Code

This is the source-code for the Apollo 9 Command Module's Guidance Computer. These files were derived originally from the scan from MIT's Dibner Institute's now-discontinued website titled "History of Recent Science and Technology", which in turn was originally created by Gary Neff, though his high-quality scans were unfortunately reduced in legibility when presented online. The markings on the front of the printout imply that it was the original AGC developer Norm Brodeur's copy. A scan by Ron Burkey has superceded it, made from a more-legible copy from the collection of original AGC developer Fred Martin. The source code was transcribed from those images by Ron Burkey. Note that the page images presented online are of reduced quality, and that higher-quality 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:

	ASSEMBLE REVISION 249 OF AGC PROGRAM COLOSSUS BY NASA 2021111-041
	20'35 OCT. 28,1968
Note that the date is the date of the printout, not the date of the program revision.

045071,000002:                                                                                                  ## Copyright:   Public domain.
045072,000003:                                                                                                  ## Filename:    RCS-CSM_DAP_EXECUTIVE_PROGRAMS.agc
045073,000004:                                                                                                  ## Purpose:     Part of the source code for Colossus, build 249.
045074,000005:                                                                                                  ##              It is part of the source code for the Command Module's (CM)
045075,000006:                                                                                                  ##              Apollo Guidance Computer (AGC), for Apollo 9.
045076,000007:                                                                                                  ## Assembler:   yaYUL
045077,000008:                                                                                                  ## Reference:   Starts on p. 1008
045078,000009:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
045079,000010:                                                                                                  ## Website:     www.ibiblio.org/apollo.
045080,000011:                                                                                                  ## Mod history: 08/26/04 RSB.   Began transcribing.
045081,000012:                                                                                                  ##              2017-01-06 RSB  Page numbers now agree with those on the
045082,000013:                                                                                                  ##                              original harcopy, as opposed to the PDF page
045083,000014:                                                                                                  ##                              numbers in 1701.pdf.
045084,000015:                                                                                                  ##              2017-01-18 RSB  Cross-diff'd comment text (not whitespace)
045085,000016:                                                                                                  ##                              vs the already-proofed corresponding Colossus
045086,000017:                                                                                                  ##                              237 and Comanche 55 source-code files
045087,000018:                                                                                                  ##                              but no errors found.
045088,000019:                                                                                                  ##
045089,000020:                                                                                                  ## The contents of the "Colossus249" files, in general, are transcribed 
045090,000021:                                                                                                  ## from a scanned copy of the program listing.  Notations on this
045091,000022:                                                                                                  ## document read, in part:
045092,000023:                                                                                                  ##
045093,000024:                                                                                                  ##      Assemble revision 249 of AGC program Colossus by NASA
045094,000025:                                                                                                  ##      2021111-041.  October 28, 1968.  
045095,000026:                                                                                                  ##
045096,000027:                                                                                                  ##      This AGC program shall also be referred to as
045097,000028:                                                                                                  ##                              Colossus 1A
045098,000029:                                                                                                  ##
045099,000030:                                                                                                  ##      Prepared by
045100,000031:                                                                                                  ##                      Massachusetts Institute of Technology
045101,000032:                                                                                                  ##                      75 Cambridge Parkway
045102,000033:                                                                                                  ##                      Cambridge, Massachusetts
045103,000034:                                                                                                  ##      under NASA contract NAS 9-4065.
045104,000035:                                                                                                  ##
045105,000036:                                                                                                  ## Refer directly to the online document mentioned above for further information.
045106,000037:                                                                                                  ## Please report any errors (relative to the scanned pages) to info@sandroid.org.
045107,000038:                                                                                                  ##
045108,000039:                                                                                                  ## In some cases, where the source code for Luminary 131 overlaps that of 
045109,000040:                                                                                                  ## Colossus 249, this code is instead copied from the corresponding Luminary 131
045110,000041:                                                                                                  ## source file, and then is proofed to incorporate any changes.
045111,000042: 

Page 1008

045113,000044:                                                                                                  #  CALCULATION OF  AMGB, AMBG  ONCE EVERY SECOND
045114,000045: 
045115,000046:                                                                                                  #        AMGB =  1       SIN(PSI)                0
045116,000047:                                                                                                  #                0       COS(PSI)COS(PHI)        SIN(PHI)
045117,000048:                                                                                                  #                0       -COS(PSI)SIN(PHI)       COS(PHI)
045118,000049: 
045119,000050:                                                                                                  #        AMBG =  1       -TAN(PSI)COS(PHI)       TAN(PSI)SIN(PHI)
045120,000051:                                                                                                  #                0       COS(PHI)/COS(PSI)       -SIN(PHI)/COS(PSI)
045121,000052:                                                                                                  #                0       SIN(PHI)                COS(PHI)
045122,000053: 
045123,000054:                                                                                                  #  WHERE PHI AND PSI ARE CDU ANGLES
045124,000055: 
045125,000056: 20,3565                                           BANK     20                                    
045126,000057: 22,2000                                           SETLOC   DAPS8                                 
045127,000058: 22,2000                                           BANK                                           
045128,000059: 
045129,000060: 22,3444                                           COUNT*   $$/DAPEX                              
045130,000061: 22,3444  E6,1510                                  EBANK=   KMPAC                                 
045131,000062: 22,3444           30102        AMBGUPDT           CA       FLAGWRD6                              #  CHECK FOR RCS AUTOPILOT
045132,000063: 22,3445           00006                           EXTEND                                         
045133,000064: 22,3446           65112                           BZMF     ENDOFJOB                              #  BIT15 = 0, BIT14 = 1
045134,000065: 22,3447           74675                           MASK     BIT14                                 #  IF NOT RCS, EXIT
045135,000066: 22,3450           00006                           EXTEND                                         
045136,000067: 22,3451           15112                           BZF      ENDOFJOB                              #  TO PROTECT TVC DAP ON SWITCHOVER
045137,000068: 
045138,000069: 22,3452           30034                           CA       CDUZ                                  
045139,000070: 22,3453           04770                           TC       SPSIN2                                
045140,000071: 22,3454           55640                           TS       AMGB1                                 #  CALCULATE AMGB
045141,000072: 22,3455           30034                           CA       CDUZ                                  
045142,000073: 22,3456           04767                           TC       SPCOS2                                
045143,000074: 22,3457           55645                           TS       CAPSI                                 #  MUST CHECK FOR GIMBAL LOCK
045144,000075: 22,3460           33504                           CAF      QUADANGL                              #  = 7.25  DEGREES JET QUAD ANGULAR OFFSET
045145,000076: 22,3461           00006                           EXTEND                                         
045146,000077: 22,3462           20032                           MSU      CDUX                                  
045147,000078: 22,3463           40000                           COM                                            #  CDUX - 7.25 DEG
045148,000079: 22,3464           04767                           TC       SPCOS1                                
045149,000080: 22,3465           55644                           TS       AMGB8                                 
045150,000081: 22,3466           00006                           EXTEND                                         
045151,000082: 22,3467           71645                           MP       CAPSI                                 
045152,000083: 22,3470           55641                           TS       AMGB4                                 
045153,000084: 22,3471           33504                           CAF      QUADANGL                              
045154,000085: 22,3472           00006                           EXTEND                                         
045155,000086: 22,3473           20032                           MSU      CDUX                                  
045156,000087: 22,3474           40000                           COM                                            #  CDUX - 7.25 DEG
045157,000088: 22,3475           04770                           TC       SPSIN1                                
045158,000089: 22,3476           55642                           TS       AMGB5                                 
045159,000090: 22,3477           00006                           EXTEND                                         
045160,000091: 22,3500           71645                           MP       CAPSI                                 
045161,000092: 22,3501           40000                           COM                                            

Page 1009

045163,000094: 22,3502           55643                           TS       AMGB7                                 
045164,000095: 22,3503           15112                           TCF      ENDOFJOB                              
045165,000096: 22,3504           01224        QUADANGL           DEC      660        B-14                       #  = 7.25 DEGREES
045166,000097: 

End of include-file RCS-CSM_DAP_EXECUTIVE_PROGRAMS.agc.  Parent file is MAIN.agc