Source Code

These source-code files are part of a reconstructed copy of Comanche 72, the first release of the Apollo Guidance Computer (AGC) Command Module (CM) software for Apollo 13.

They have been adapted from sources files created from a listing of Comanche 55. These source files were updated to match binary dumps of a set of Comanche 67 rope modules. They were then further modified by applying known changes between Comanche 67 and Comanche 72. A binary dump of module B2 of Comanche 72, part number 2010802-021, was also used to validate changes made to banks 05-13. The resulting code assembles to have identical memory-bank checksums as those specified in NASA drawing 2021153G; this gives reasonably high confidence that the changes that have been made are correct. In places where ambiguity exists, this ambiguity is discussed in "## Reconstruction:" comments.

Since no contemporary listings of Comanche 72 are available as source material, all comments and labels are approximate. They have been taken from other AGC programs where possible, or, in some places, written from scratch to match what we believe would have been in the original listing.

040114,000002:                                                                                                  ## Copyright:   Public domain.
040115,000003:                                                                                                  ## Filename:    S-BAND_ANTENNA_FOR_CM.agc
040116,000004:                                                                                                  ## Purpose:     A section of Comanche revision 072.
040117,000005:                                                                                                  ##              It is part of the reconstructed source code for the first
040118,000006:                                                                                                  ##              release of the software for the Command Module's (CM) Apollo
040119,000007:                                                                                                  ##              Guidance Computer (AGC) for Apollo 13. No original listings
040120,000008:                                                                                                  ##              of this program are available; instead, this file was recreated
040121,000009:                                                                                                  ##              from a printout of Comanche 055, binary dumps of a set of
040122,000010:                                                                                                  ##              Comanche 067 rope modules, and changelogs between Comanche 067
040123,000011:                                                                                                  ##              and 072. It has been adapted such that the resulting bugger words
040124,000012:                                                                                                  ##              exactly match those specified for Comanche 072 in NASA drawing
040125,000013:                                                                                                  ##              2021153G, which gives relatively high confidence that the
040126,000014:                                                                                                  ##              reconstruction is correct.
040127,000015:                                                                                                  ## Assembler:   yaYUL
040128,000016:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
040129,000017:                                                                                                  ## Website:     www.ibiblio.org/apollo/index.html
040130,000018:                                                                                                  ## Mod history: 2024-05-13 MAS  Created from Comanche 067.
040131,000019: 
040132,000020: 23,3207                                           BANK     23                                    
040133,000021: 42,2000                                           SETLOC   SBAND                                 
040134,000022: 42,2000                                           BANK                                           
040135,000023: 
040136,000024: 42,3651                                           COUNT*   $$/R05                                
040137,000025: 42,3651  E4,1417                                  EBANK=   EMSALT                                
040138,000026: 
040139,000027: 42,3651           06006        SBANDANT           TC       INTPRET                               
040140,000028: 42,3652           45034                           RTB      CALL                                  
040141,000029: 42,3653           45510                                    LOADTIME                              #  PICKUP CURRENT TIME SCALED B-28
040142,000030: 42,3654           47501                                    CDUTRIG                               #  COMPUTE SINES AND COSINES OF CDU ANGLES
040143,000031: 42,3655           34041                           STCALL   TDEC1                                 #  ADVANCE INTEGRATION TO TIME IN TDEC1
040144,000032: 42,3656           27123                                    CSMCONIC                              #  USING CONIC INTEGRATION
040145,000033: 42,3657           46135                           SLOAD    BHIZ                                  #  ORIGIN OF REFERENCE INERTIAL SYSTEM IS
040146,000034: 42,3660           00050                                    X2                                    #  EARTH = 0, MOON = 2
040147,000035: 42,3661           65674                                    EISOI                                 
040148,000036: 42,3662           77775                           VLOAD                                          
040149,000037: 42,3663           00001                                    RATT                                  
040150,000038: 42,3664           00003                           STORE    RCM                                   #  MOVE RATT TO PREVENT WIPEOUT
040151,000039: 42,3665           45145                           DLOAD    CALL                                  #  MOON, PUSH ON
040152,000040: 42,3666           00015                                    TAT                                   #  GET ORIGINAL TIME
040153,000041: 42,3667           54115                                    LUNPOS                                #  COMPUTE POSITION VECTOR OF MOON
040154,000042: 42,3670           57455                           VAD      VCOMP                                 #  R= -(REM+RCM) = NEG. OF S/C POS. VEC
040155,000043: 42,3671           00003                                    RCM                                   
040156,000044: 42,3672           77650                           GOTO                                           
040157,000045: 42,3673           65676                                    EISOI      +2                         
040158,000046: 42,3674           57575        EISOI              VLOAD    VCOMP                                 #  EARTH, R= -RCM
040159,000047: 42,3675           00001                                    RATT                                  
040160,000048: 42,3676           64201                           SETPD    MXV                                   #  RCS TO STABLE MEMBER- B-1X B-29X B+1
040161,000049: 42,3677           00003                                    2D                                    #  2D
040162,000050: 42,3700           01736                                    REFSMMAT                              #  STABLE MEMBER.  B-1X B-29X B+1= B-29
040163,000051: 42,3701           65372                           VSL1     PDDL                                  #  8D
040164,000052: 42,3702           15334                                    HI6ZEROS                              
040165,000053: 42,3703           24025                           STOVL    YAWANG                                #  ZERO OUT YAWANG, SET UP FOR SMNB
040166,000054: 42,3704           00003                                    RCM                                   #  TRANSFORMATION.  SM COORD.  SCALED B-29
040167,000055: 42,3705           77624                           CALL                                           
040168,000056: 42,3706           47646                                    *SMNB*                                
040169,000057: 42,3707           00003                           STORE    R                                     #  SAVE NAV. BASE COORDINATES
040170,000058: 42,3710           63256                           UNIT     PDVL                                  #  14D
040171,000059: 42,3711           00003                                    R                                     
040172,000060: 42,3712           72431                           VPROJ    VSL2                                  #  COMPUTE PROJECTION OF VECTOR INTO CM
040173,000061: 42,3713           15326                                    HIUNITZ                               #  XY-PLANE, R-(R.UZ)UZ
040174,000062: 42,3714           40045                           BVSU     BOV                                   #  CLEAR OVERFLOW INDICATOR IF SET
040175,000063: 42,3715           00003                                    R                                     
040176,000064: 42,3716           65717                                    COVCNV                                
040177,000065: 42,3717           40056        COVCNV             UNIT     BOV                                   #  TEST OVERFLOW FOR INDICATION OF NULL
040178,000066: 42,3720           65734                                    NOADJUST                              #  VECTOR
040179,000067: 42,3721           50206                           PUSH     DOT                                   #  20D
040180,000068: 42,3722           15332                                    HIUNITX                               #  COMPUTE YAW ANGLE = ACOS (URP.UX)
040181,000069: 42,3723           65552                           SL1      ACOS                                  #  REVOLUTIONS SCALED B0
040182,000070: 42,3724           50315                           PDVL     DOT                                   #  22D YAWANG
040183,000071: 42,3725           00017                                    URP                                   
040184,000072: 42,3726           15330                                    HIUNITY                               #  COMPUTE FOLLOWING- URP.UY
040185,000073: 42,3727           51152                           SL1      BPL                                   #  POSITIVE
040186,000074: 42,3730           65734                                    NOADJUST                              #  YES, 0-180 DEGREES
040187,000075: 42,3731           45345                           DLOAD    DSU                                   #  NO, 181-360 DEGREES 20D
040188,000076: 42,3732           15342                                    DPPOSMAX                              #  COMPUTE 2 PI MINUS YAW ANGLE
040189,000077: 42,3733           77606                           PUSH                                           #  22D YAWANG
040190,000078: 42,3734           50375        NOADJUST           VLOAD    DOT                                   #  COMPUTE PITCH ANGLE
040191,000079: 42,3735           00011                                    UR                                    #  ACOS (UR.UZ) - PI/2
040192,000080: 42,3736           15326                                    HIUNITZ                               
040193,000081: 42,3737           65552                           SL1      ACOS                                  #  REVOLUTIONS B0
040194,000082: 42,3740           77625                           DSU                                            
040195,000083: 42,3741           15324                                    HIDP1/4                               
040196,000084: 42,3742           16321                           STODL    RHOSB                                 
040197,000085: 42,3743           00025                                    YAWANG                                
040198,000086: 42,3744           02323                           STORE    GAMMASB                               #  PATCH FOR CHECKOUT
040199,000087: 42,3745           77776                           EXIT                                           
040200,000088: 42,3746           31044                           CA       EXTVBACT                              #  IS BIT 5 STILL ON
040201,000089: 42,3747           75027                           MASK     BIT5                                  
040202,000090: 42,3750           00006                           EXTEND                                         
040203,000091: 42,3751           15550                           BZF      ENDEXT                                #  NO, WE HAVE BEEN ANSWERED
040204,000092: 42,3752           33766                           CAF      V06N51                                #  DISPLAY ANGLES
040205,000093: 42,3753           04676                           TC       BANKCALL                              
040206,000094: 42,3754           20600                           CADR     GOMARKFR                              
040207,000095: 42,3755           05641                           TC       B5OFF                                 #  TERMINATE
040208,000096: 42,3756           05641                           TC       B5OFF                                 
040209,000097: 42,3757           05233                           TC       ENDOFJOB                              #  RECYCLE
040210,000098: 42,3760           35031                           CAF      BIT3                                  #  IMMEDIATE RETURN
040211,000099: 42,3761           05542                           TC       BLANKET                               #  BLANK R3
040212,000100: 42,3762           35033                           CAF      BIT1                                  #  DELAY MINIMUM TIME TO ALLOW DISPLAY IN
040213,000101: 42,3763           04676                           TC       BANKCALL                              
040214,000102: 42,3764           01732                           CADR     DELAYJOB                              
040215,000103: 42,3765           13651                           TCF      SBANDANT                              
040216,000104: 42,3766           01463        V06N51             VN       0651                                  
040217,000105: 42,3767                        RCM                EQUALS   2D                                    
040218,000106: 42,3767                        UR                 EQUALS   8D                                    
040219,000107: 42,3767                        URP                EQUALS   14D                                   
040220,000108: 42,3767                        YAWANG             EQUALS   20D                                   
040221,000109: 42,3767                        PITCHANG           EQUALS   22D                                   
040222,000110: 42,3767  0000002               R                  EQUALS   RCM                                   
040223,000111: 42,3767  30,2000                                  SBANK=   LOWSUPER                              
040224,000112: 

End of include-file S-BAND_ANTENNA_FOR_CM.agc.  Parent file is MAIN.agc