Source Code

These source-code files are part of a reconstructed copy of Comanche 72/3 (AKA Manche72 revision 3), the final, flown mission release of the Apollo Guidance Computer (AGC) Command Module (CM) software for Apollo 13.

The starting point was the source code of Comanche 72 (itself previously reconstructed). Comanche 72 source code was then modified by incorporating changes known from contemporary documentation to have been made between revisions 72 and 72/3. 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 72/3 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.

021135,000002:                                                                                                  ## Copyright:   Public domain.
021136,000003:                                                                                                  ## Filename:    R31.agc
021137,000004:                                                                                                  ## Purpose:     A section of Manche72 revision 3.
021138,000005:                                                                                                  ##              It is part of the reconstructed source code for the final, flown
021139,000006:                                                                                                  ##              release of the software for the Command Module's (CM) Apollo
021140,000007:                                                                                                  ##              Guidance Computer (AGC) for Apollo 13. No original listings
021141,000008:                                                                                                  ##              of this program are available; instead, this file was recreated
021142,000009:                                                                                                  ##              from a reconstructed copy of Comanche 072. It has been adapted
021143,000010:                                                                                                  ##              such that the resulting bugger words exactly match those
021144,000011:                                                                                                  ##              specified for Manche72 revision 3 in NASA drawing 2021153G,
021145,000012:                                                                                                  ##              which gives relatively high confidence that the reconstruction
021146,000013:                                                                                                  ##              is correct.
021147,000014:                                                                                                  ## Assembler:   yaYUL
021148,000015:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
021149,000016:                                                                                                  ## Website:     www.ibiblio.org/apollo/index.html
021150,000017:                                                                                                  ## Mod history: 2024-05-19 MAS  Created from Comanche 072.
021151,000018: 
021152,000019: 34,2002                                           BANK     34                                    
021153,000020: 31,2000                                           SETLOC   R31                                   
021154,000021: 31,2000                                           BANK                                           
021155,000022: 
021156,000023: 31,2000                                           COUNT*   $$/R31                                
021157,000024: 
021158,000025: 31,2000           35073        R31CALL            CAF      PRIO3                                 
021159,000026: 31,2001           05163                           TC       FINDVAC                               
021160,000027: 31,2002  E4,1770                                  EBANK=   SUBEXIT                               
021161,000028: 31,2002           02032 62064                     2CADR    V83CALL                               
021162,000029: 
021163,000030: 31,2004           35055        DSPDELAY           CAF      1SEC                                  
021164,000031: 31,2005           04676                           TC       BANKCALL                              
021165,000032: 31,2006           01732                           CADR     DELAYJOB                              
021166,000033: 31,2007           31044                           CA       EXTVBACT                              
021167,000034: 31,2010           75020                           MASK     BIT12                                 
021168,000035: 31,2011           00006                           EXTEND                                         
021169,000036: 31,2012           12004                           BZF      DSPDELAY                              
021170,000037: 
021171,000038: 31,2013           30105        DISPN5X            CA       FLAGWRD9                              #  TEST R31FLAG (IN SUNDANCE R31FLAG WILL
021172,000039: 31,2014           75030                           MASK     BIT4                                  #        ALWAYS BE SET AS R34 DOES NOT EXIST)
021173,000040: 31,2015           00006                           EXTEND                                         
021174,000041: 31,2016           12021                           BZF      +3                                    
021175,000042: 31,2017           32136                           CAF      V16N54                                #  R31   USE NOUN 54
021176,000043: 31,2020           02022                           TC       +2                                    
021177,000044: 31,2021           32137                           CAF      V16N53                                #  R34   USE NOUN 53
021178,000045: 31,2022           04676                           TC       BANKCALL                              
021179,000046: 31,2023           20561                           CADR     GOMARKF                               
021180,000047: 31,2024           05641                           TC       B5OFF                                 
021181,000048: 31,2025           05641                           TC       B5OFF                                 
021182,000049: 31,2026           12013                           TCF      DISPN5X                               
021183,000050: 
021184,000051: 31,2027           06006        V83                TC       INTPRET                               
021185,000052: 31,2030           77650                           GOTO                                           
021186,000053: 31,2031           62171                                    HAVEBASE                              #  INTEG STATE VECTORS
021187,000054: 31,2032           06006        V83CALL            TC       INTPRET                               
021188,000055: 31,2033           77650                           GOTO                                           
021189,000056: 31,2034           62140                                    STATEXTP                              #  EXTRAPOLATE STATE VECTORS
021190,000057: 31,2035           52375        COMPDISP           VLOAD    VSU                                   
021191,000058: 31,2036           00001                                    RATT                                  
021192,000059: 31,2037           02327                                    RONE                                  
021193,000060: 31,2040           51406                           PUSH     ABVAL                                 #  RATT-RONE TO 0D       PD= 6
021194,000061: 31,2041           02321                           STORE    RANGE                                 #  METERS B-29
021195,000062: 31,2042           77301                           NORM     VLOAD                                 
021196,000063: 31,2043           00047                                    X1                                    #  RATT-RONE             PD= 0
021197,000064: 31,2044           77762                           VSR1                                           
021198,000065: 31,2045           53457                           VSL*     UNIT                                  
021199,000066: 31,2046           20201                                    0,1                                   
021200,000067: 31,2047           52315                           PDVL     VSU                                   #  UNIT(LOS) TO 0D       PD= 6
021201,000068: 31,2050           00007                                    VATT                                  
021202,000069: 31,2051           02335                                    VONE                                  
021203,000070: 31,2052           77641                           DOT                                            #  (VATT-VONE).UNIT(LOS) PD= 0
021204,000071: 31,2053           77752                           SL1                                            
021205,000072: 31,2054           36323                           STCALL   RRATE                                 #  RANGE RATE M/CS B-7
021206,000073: 31,2055           47501                                    CDUTRIG                               #  TO INITIALIZE FOR *NBSM*
021207,000074: 31,2056           77624                           CALL                                           
021208,000075: 31,2057           62311                                    R34LOS                                #  NOTE.  PDL MUST = 0.
021209,000076: 31,2060           53575        R34ANG             VLOAD    UNIT                                  
021210,000077: 31,2061           02327                                    RONE                                  
021211,000078: 31,2062           77715                           PDVL                                           #  UR TO 0D              PD= 6
021212,000079: 31,2063           15332                                    THISAXIS                              #  UNITX FOR CM, UNITZ FOR LM
021213,000080: 31,2064           77214                           BON      VLOAD                                 #  CHK R31FLAG.  ON=R31 THETA, OFF=R34 PHI
021214,000081: 31,2065           04713                                    R31FLAG                               
021215,000082: 31,2066           62070                                    +2                                    #  R31-THETA
021216,000083: 31,2067           00015                                    12D                                   
021217,000084: 31,2070           77624                           CALL                                           
021218,000085: 31,2071           47650                                    *NBSM*                                
021219,000086: 31,2072           41505                           VXM      PUSH                                  #  UXORZ TO 6D           PD=12D
021220,000087: 31,2073           01736                                    REFSMMAT                              
021221,000088: 31,2074           72431                           VPROJ    VSL2                                  
021222,000089: 31,2075           00001                                    0D                                    
021223,000090: 31,2076           53445                           BVSU     UNIT                                  
021224,000091: 31,2077           00007                                    6D                                    
021225,000092: 31,2100           47315                           PDVL     VXV                                   #  UP/2 TO 12D           PD=18D
021226,000093: 31,2101           02327                                    RONE                                  
021227,000094: 31,2102           02335                                    VONE                                  
021228,000095: 31,2103           47256                           UNIT     VXV                                   
021229,000096: 31,2104           02327                                    RONE                                  
021230,000097: 31,2105           63241                           DOT      PDVL                                  #  SIGN TO 12D, UP/2 TO MPAC     PD=18D
021231,000098: 31,2106           00015                                    12D                                   
021232,000099: 31,2107           50372                           VSL1     DOT                                   #  UP.UXORZ
021233,000100: 31,2110           00007                                    6D                                    
021234,000101: 31,2111           72565                           SIGN     SL1                                   
021235,000102: 31,2112           00015                                    12D                                   
021236,000103: 31,2113           77726                           ACOS                                           
021237,000104: 31,2114           26325                           STOVL    RTHETA                                
021238,000105: 31,2115           02327                                    RONE                                  
021239,000106: 31,2116           51041                           DOT      BPL                                   
021240,000107: 31,2117           00007                                    6D                                    
021241,000108: 31,2120           62125                                    +5                                    
021242,000109: 31,2121           44345                           DLOAD    BDSU                                  #  IF UXORZ.R NEG, RTHETA = 1 - RTHETA
021243,000110: 31,2122           02325                                    RTHETA                                
021244,000111: 31,2123           15342                                    DPPOSMAX                              
021245,000112: 31,2124           02325                           STORE    RTHETA                                #  RTHETA BETWEEN 0 AND 1 REV.
021246,000113: 31,2125           77776                           EXIT                                           
021247,000114: 31,2126           35027                           CAF      BIT5                                  #  HAVE WE BEEN ANSWERED
021248,000115: 31,2127           71044                           MASK     EXTVBACT                              
021249,000116: 31,2130           00006                           EXTEND                                         
021250,000117: 31,2131           15550                           BZF      ENDEXT                                #  YES, DIE
021251,000118: 31,2132           41044                           CS       EXTVBACT                              
021252,000119: 31,2133           75020                           MASK     BIT12                                 
021253,000120: 31,2134           27044                           ADS      EXTVBACT                              
021254,000121: 
021255,000122: 31,2135           12027                           TCF      V83                                   
021256,000123: 31,2136           04066        V16N54             VN       1654                                  
021257,000124: 31,2137           04065        V16N53             VN       1653                                  
021258,000125: 
021259,000126:                                                                                                  #  STATEXTP DOES AN INITIAL PRECISION EXTRAPOLATION OF THE
021260,000127:                                                                                                  #  LEM STATE VECTOR TO PRESENT TIME OR TO PIPTIME IF AV G
021261,000128:                                                                                                  #  IS ON AND SAVES AS BASE VECTOR. IF AV G IS ON RN + VN
021262,000129:                                                                                                  #  ARE USED AS THE CM STATE VECTOR AND THE INITIAL R RDOT
021263,000130:                                                                                                  #  RTHETA ARE COMPUTED WITH NO FURTHER INTEGRATION. IF AV
021264,000131:                                                                                                  #  G IS OFF A PRECISION EXTRAPOLATION IS MADE OF THE CM
021265,000132:                                                                                                  #  STATE VECTOR TO PRESENT TIME AND.....
021266,000133: 
021267,000134:                                                                                                  #    THE CM + LM STATE VECTORS ARE INTEGRATED TO PRES TIME
021268,000135:                                                                                                  #    USING PRECISION OR CONIC AS SURFFLAG IS SET OR CLEAR.
021269,000136: 
021270,000137:                                                                                                  #    IF AV G IS ON THEN SUBSEQUENT PASSES WILL PROVIDE
021271,000138:                                                                                                  #      USE OF RN + VN AS CM STATE VECTOR AND THE LM STATE
021272,000139:                                                                                                  #      VECTOR WILL BE PRECISION INTEGRATED USING LEMPREC
021273,000140: 
021274,000141:                                                                                                  #    IF SURFFLAG IS SET.
021275,000142:                                                                                                  #      CM STATE VECTOR RONE VONE + LM STATE VECTOR RATT
021276,000143:                                                                                                  #      VATT ARE USED IN COMPUTING R RDOT RTHETA.
021277,000144: 
021278,000145: 
021279,000146: 31,2140           43034        STATEXTP           RTB      BOF                                   #  INITIAL INTEGRATION
021280,000147: 31,2141           45510                                    LOADTIME                              
021281,000148: 31,2142           03751                                    V37FLAG                               
021282,000149: 31,2143           62146                                    +3                                    #  AV G OFF, USE PRES TIME
021283,000150: 31,2144           77624                           CALL                                           
021284,000151: 31,2145           62273                                    GETRVN                                #       ON,  USE RN VN PIPTIME
021285,000152: 31,2146           02343                           STORE    BASETIME                              #  PRES TIME OR PIPTIME
021286,000153: 31,2147           34041                           STCALL   TDEC1                                 
021287,000154: 31,2150           27114                                    LEMPREC                               
021288,000155: 31,2151           77775                           VLOAD                                          #  BASE VECTOR, LM
021289,000156: 31,2152           00017                                    RATT1                                 
021290,000157: 31,2153           26225                           STOVL    BASEOTP                               #    POS.
021291,000158: 31,2154           00025                                    VATT1                                 
021292,000159: 31,2155           02241                           STORE    BASEOTV                               #    VEL.
021293,000160: 31,2156           71214                           BON      DLOAD                                 
021294,000161: 31,2157           03711                                    V37FLAG                               
021295,000162: 31,2160           62035                                    COMPDISP                              #  COMPUTE R RDOT RTHETA FROM
021296,000163:                                                                                                  #  RONE(RN) VONE(VN) RATT+VATT(LEMPREC)
021297,000164: 31,2161           00015                                    TAT                                   
021298,000165: 31,2162           34041                           STCALL   TDEC1                                 
021299,000166: 31,2163           27100                                    CSMPREC                               
021300,000167: 31,2164           77775                           VLOAD                                          #  BASE VECTOR, CM
021301,000168: 31,2165           00017                                    RATT1                                 
021302,000169: 31,2166           26255                           STOVL    BASETHP                               #   POS.
021303,000170: 31,2167           00025                                    VATT1                                 
021304,000171: 31,2170           02263                           STORE    BASETHV                               #   VEL.
021305,000172: 31,2171           47014        HAVEBASE           BON      RTB                                   #  SUBSEQUENT INTEGRATIONS
021306,000173: 31,2172           03711                                    V37FLAG                               
021307,000174: 31,2173           62256                                    GETRVN5                               
021308,000175: 31,2174           45510                                    LOADTIME                              
021309,000176: 31,2175           34041                           STCALL   TDEC1                                 #  AV G OFF. SET INTEG. OF CM
021310,000177: 31,2176           27446                                    INTSTALL                              
021311,000178: 31,2177           43175                           VLOAD    CLEAR                                 
021312,000179: 31,2200           02255                                    BASETHP                               
021313,000180: 31,2201           00263                                    MOONFLAG                              
021314,000181: 31,2202           25535                           STOVL    RCV                                   
021315,000182: 31,2203           02263                                    BASETHV                               
021316,000183: 31,2204           15543                           STODL    VCV                                   
021317,000184: 31,2205           02343                                    BASETIME                              
021318,000185: 31,2206           43014                           BOF      SET                                   #  GET APPROPRIATE MOONFLAG SETTING
021319,000186: 31,2207           04343                                    MOONTHIS                              
021320,000187: 31,2210           62212                                    +2                                    
021321,000188: 31,2211           00063                                    MOONFLAG                              
021322,000189: 31,2212           77614                           CLEAR                                          
021323,000190: 31,2213           01673                                    INTYPFLG                              
021324,000191: 31,2214           43014                           BON      SET                                   
021325,000192: 31,2215           04307                                    SURFFLAG                              
021326,000193: 31,2216           62220                                    +2                                    #  PREC. IF LM DOWN
021327,000194: 31,2217           01473                                    INTYPFLG                              #  CONIC IF LM NOT DOWN
021328,000195: 31,2220           35517                           STCALL   TET                                   
021329,000196: 31,2221           27144                                    INTEGRVS                              #  INTEGRATION --- AT LAST---
021330,000197: 31,2222           77775                           VLOAD                                          
021331,000198: 31,2223           00001                                    RATT                                  
021332,000199: 31,2224           26327                           STOVL    RONE                                  
021333,000200: 31,2225           00007                                    VATT                                  
021334,000201: 31,2226           16335                           STODL    VONE                                  #  GET SET FOR CONIC EXTRAP.,OTHER
021335,000202: 31,2227           00015                                    TAT                                   
021336,000203: 31,2230           45014                           BON      CALL                                  
021337,000204: 31,2231           04307                                    SURFFLAG                              
021338,000205: 31,2232           62267                                    GETRVN6                               #  LEMPREC IF LM DOWN
021339,000206: 31,2233           27446                                    INTSTALL                              #  ..CONIC IF NOT DOWN
021340,000207: 31,2234           77614                           SET                                            
021341,000208: 31,2235           01473                                    INTYPFLG                              
021342,000209: 31,2236           00041        OTHINT             STORE    TDEC1                                 #  ENTERED IF AV G ON TO INTEG LM
021343,000210: 31,2237           43175                           VLOAD    CLEAR                                 
021344,000211: 31,2240           02225                                    BASEOTP                               
021345,000212: 31,2241           00263                                    MOONFLAG                              
021346,000213: 31,2242           25535                           STOVL    RCV                                   
021347,000214: 31,2243           02241                                    BASEOTV                               
021348,000215: 31,2244           15543                           STODL    VCV                                   
021349,000216: 31,2245           02343                                    BASETIME                              
021350,000217: 31,2246           43014                           BOF      SET                                   
021351,000218: 31,2247           04343                                    MOONTHIS                              
021352,000219: 31,2250           62252                                    +2                                    
021353,000220: 31,2251           00063                                    MOONFLAG                              
021354,000221: 31,2252           35517                           STCALL   TET                                   
021355,000222: 31,2253           27144                                    INTEGRVS                              
021356,000223: 31,2254           77650                           GOTO                                           
021357,000224: 31,2255           62035                                    COMPDISP                              #  COMPUTE R RDOT RTHETA         
021358,000225: 31,2256           77624        GETRVN5            CALL                                           #  AV G ON
021359,000226: 31,2257           62273                                    GETRVN                                
021360,000227: 31,2260           45014                           BON      CALL                                  
021361,000228: 31,2261           04307                                    SURFFLAG                              
021362,000229: 31,2262           62267                                    GETRVN6                               #  LM DOWN, LMPREC
021363,000230: 31,2263           27446                                    INTSTALL                              
021364,000231: 31,2264           52014                           CLEAR    GOTO                                  
021365,000232: 31,2265           01673                                    INTYPFLG                              
021366,000233: 31,2266           62236                                    OTHINT                                
021367,000234: 31,2267           34041        GETRVN6            STCALL   TDEC1                                 
021368,000235: 31,2270           27114                                    LEMPREC                               
021369,000236: 31,2271           77650                           GOTO                                           
021370,000237: 31,2272           62035                                    COMPDISP                              #  COMPUTE R RDOT RTHETA
021371,000238: 31,2273           77620        GETRVN             STQ                                            
021372,000239: 31,2274           00000                                    0D                                    
021373,000240: 31,2275           52175                           VLOAD    GOTO                                  #  AV G ON, RONE = RN VONE = VN
021374,000241: 31,2276           01171                                    RN                                    #   AND USE PIPTIME
021375,000242: 31,2277           62300                                    +1                                    
021376,000243: 31,2300           36327                           STCALL   RONE                                  
021377,000244: 31,2301           62302                                    +1                                    
021378,000245: 31,2302           52175                           VLOAD    GOTO                                  
021379,000246: 31,2303           01177                                    VN                                    
021380,000247: 31,2304           62305                                    +1                                    
021381,000248: 31,2305           16335                           STODL    VONE                                  
021382,000249: 31,2306           01205                                    PIPTIME                               
021383,000250: 31,2307           77650                           GOTO                                           
021384,000251: 31,2310           00000                                    0D                                    
021385,000252: 31,2000                                           SETLOC   R34                                   
021386,000253: 31,2000                                           BANK                                           
021387,000254: 31,2311           77776        R34LOS             EXIT                                           
021388,000255: 31,2312           30036                           CA       CDUS                                  
021389,000256: 31,2313           50120                           INDEX    FIXLOC                                
021390,000257: 31,2314           54011                           TS       9D                                    
021391,000258: 31,2315           30035                           CA       CDUT                                  
021392,000259: 31,2316           50120                           INDEX    FIXLOC                                
021393,000260: 31,2317           54013                           TS       11D                                   
021394,000261: 31,2320           30120                           CA       FIXLOC                                
021395,000262: 31,2321           66211                           AD       SIX                                   
021396,000263: 31,2322           40000                           COM                                            
021397,000264: 31,2323           50120                           INDEX    FIXLOC                                
021398,000265: 31,2324           54046                           TS       X1                                    
021399,000266: 31,2325           06006                           TC       INTPRET                               
021400,000267: 31,2326           77624                           CALL                                           
021401,000268: 31,2327           46000                                    SXTNB                                 
021402,000269: 31,2330           34015                           STCALL   12D                                   
021403,000270: 31,2331           62060                                    R34ANG                                

End of include-file R31.agc.  Parent file is MAIN.agc