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.

042899,000002:                                                                                                  ## Copyright:   Public domain.
042900,000003:                                                                                                  ## Filename:    MYSUBS.agc
042901,000004:                                                                                                  ## Purpose:     A section of Manche72 revision 3.
042902,000005:                                                                                                  ##              It is part of the reconstructed source code for the final, flown
042903,000006:                                                                                                  ##              release of the software for the Command Module's (CM) Apollo
042904,000007:                                                                                                  ##              Guidance Computer (AGC) for Apollo 13. No original listings
042905,000008:                                                                                                  ##              of this program are available; instead, this file was recreated
042906,000009:                                                                                                  ##              from a reconstructed copy of Comanche 072. It has been adapted
042907,000010:                                                                                                  ##              such that the resulting bugger words exactly match those
042908,000011:                                                                                                  ##              specified for Manche72 revision 3 in NASA drawing 2021153G,
042909,000012:                                                                                                  ##              which gives relatively high confidence that the reconstruction
042910,000013:                                                                                                  ##              is correct.
042911,000014:                                                                                                  ## Assembler:   yaYUL
042912,000015:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
042913,000016:                                                                                                  ## Website:     www.ibiblio.org/apollo/index.html
042914,000017:                                                                                                  ## Mod history: 2024-05-19 MAS  Created from Comanche 072.
042915,000018: 
042916,000019: 20,3650                                           BANK     20                                    
042917,000020: 21,2000                                           SETLOC   MYSUBS                                
042918,000021: 21,2000                                           BANK                                           
042919,000022: 
042920,000023: 21,2054  E6,1510                                  EBANK=   KMPAC                                 
042921,000024: 21,2054     5110               SPCOS1             EQUALS   SPCOS                                 
042922,000025: 21,2054     5111               SPSIN1             EQUALS   SPSIN                                 
042923,000026: 21,2054     5110               SPCOS2             EQUALS   SPCOS                                 
042924,000027: 21,2054     5111               SPSIN2             EQUALS   SPSIN                                 
042925,000028: 
042926,000029: 21,2054                                           COUNT    21/DAPMS                              
042927,000030: 
042928,000031:                                                                                                  #  ONE AND ONE HALF PRECISION MULTIPLICATION ROUTINE
042929,000032: 
042930,000033: 21,2054           55512        SMALLMP            TS       KMPTEMP                               #  A(X+Y)
042931,000034: 21,2055           00006                           EXTEND                                         
042932,000035: 21,2056           71511                           MP       KMPAC      +1                         
042933,000036: 21,2057           55511                           TS       KMPAC      +1                         #  AY
042934,000037: 21,2060           35035                           CAF      ZERO                                  
042935,000038: 21,2061           57510                           XCH      KMPAC                                 
042936,000039: 21,2062           00006                           EXTEND                                         
042937,000040: 21,2063           71512                           MP       KMPTEMP                               #  AX
042938,000041: 21,2064           21511                           DAS      KMPAC                                 #  AX+AY
042939,000042: 21,2065           00002                           TC       Q                                     
042940,000043: 
042941,000044:                                                                                                  #  SUBROUTINE FOR DOUBLE PRECISION ADDITIONS OF ANGLES
042942,000045:                                                                                                  #  A AND L CONTAIN A DP(1S) ANGLE SCALED BY 180 DEGS TO BE ADDED TO KMPAC.
042943,000046:                                                                                                  #  RESULT IS PLACED IN KMPAC.  TIMING = 6 MCT (22 MCT ON OVERFLOW)
042944,000047: 
042945,000048: 21,2066           21511        DPADD              DAS      KMPAC                                 
042946,000049: 21,2067           00006                           EXTEND                                         
042947,000050: 21,2070           12105                           BZF      TSK        +1                         #  NO OVERFLOW
042948,000051: 21,2071           11510                           CCS      KMPAC                                 
042949,000052: 21,2072           12106                           TCF      DPADD+                                #  + OVERFLOW
042950,000053: 21,2073           12075                           TCF      +2                                    
042951,000054: 21,2074           12110                           TCF      DPADD-                                #  - OVERFLOW
042952,000055: 21,2075           11511                           CCS      KMPAC      +1                         
042953,000056: 21,2076           12113                           TCF      DPADD2+                               #  UPPER = 0, LOWER +
042954,000057: 21,2077           12101                           TCF      +2                                    
042955,000058: 21,2100           40000                           COM                                            #  UPPER = 0, LOWER -
042956,000059: 21,2101           65013                           AD       POSMAX                                #  LOWER = 0, A = 0
042957,000060: 21,2102           55511                           TS       KMPAC      +1                         #  CAN NOT OVERFLOW
042958,000061: 21,2103           35013                           CA       POSMAX                                #  UPPER WAS = 0
042959,000062: 21,2104           55510        TSK                TS       KMPAC                                 
042960,000063: 21,2105           00002                           TC       Q                                     
042961,000064: 
042962,000065: 21,2106           65015        DPADD+             AD       NEGMAX                                #  KMPAC GREATER THAN 0
042963,000066: 21,2107           12104                           TCF      TSK                                   
042964,000067: 
042965,000068: 21,2110           40000        DPADD-             COM                                            
042966,000069: 21,2111           65013                           AD       POSMAX                                #  KMPAC LESS THAN 0
042967,000070: 21,2112           12104                           TCF      TSK                                   
042968,000071: 
042969,000072: 21,2113           65015        DPADD2+            AD       NEGMAX                                #  CAN NOT OVERFLOW
042970,000073: 21,2114           55511                           TS       KMPAC      +1                         
042971,000074: 21,2115           35015                           CA       NEGMAX                                #  UPPER WAS = 0
042972,000075: 21,2116           12104                           TCF      TSK                                   

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