Source Code

These source-code files were obtained by digitally photographing the Colossus 237 program listing from the private collection of original AGC developer Fred Martin, and then modifying pre-existing Colossus 249 (Apollo 9) source files to incorporate changes. Note that the page images presented online are of reduced quality, and that additional 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:

	GAP: ASSEMBLE REVISION 237 OF AGC PROGRAM COLOSSUS 
	BY NASA 2021111-031  1:17 AUG. 24, 1968

019495,000002:                                                                                                 #  Copyright:    Public domain.
019496,000003:                                                                                                 #  Filename:      GROUND_TRACKING_DETERMINATION_PROGRAM_-_P21.agc
019497,000004:                                                                                                 #  Purpose:      Part of the source code for Colossus build 237.
019498,000005:                                                                                                 #                This is for the Command Module's (CM) Apollo Guidance
019499,000006:                                                                                                 #                Computer (AGC), we believe for Apollo 8.
019500,000007:                                                                                                 #  Assembler:    yaYUL
019501,000008:                                                                                                 #  Contact:      Jim Lawton <jim DOT lawton AT gmail DOT com>
019502,000009:                                                                                                 #  Website:      www.ibiblio.org/apollo/index.html
019503,000010:                                                                                                 #  Page scans:   www.ibiblio.org/apollo/ScansForConversion/Colossus237/
019504,000011:                                                                                                 #  Mod history:  2011-02-02 JL   Adapted from corresponding Colossus 249 file.
019505,000012: 
019506,000013:                                                                                                 # # Page 447
019507,000014:                                                                                                 #  GROUND TRACKING DETERMINATION PROGRAM P21
019508,000015:                                                                                                 #  PROGRAM DESCRIPTION
019509,000016:                                                                                                 #  MOD NO - 1
019510,000017:                                                                                                 #  MOD BY - N.M.NEVILLE
019511,000018:                                                                                                 #  FUNCTIONAL DESCRIPTION-
019512,000019: 
019513,000020:                                                                                                 #  TO PROVIDE THE ASTRONAUT DETAILS OF THE LM OR CSM GROUND TRACK WITHOUT
019514,000021:                                                                                                 #  THE NEED FOR GROUND COMMUNICATION (REQUESTED BY DSKY).
019515,000022:                                                                                                 #  CALLING SEQUENCE-
019516,000023: 
019517,000024:                                                                                                 #  ASTRONAUT REQUEST THROUGH DSKY V37E21E
019518,000025:                                                                                                 #  SUBROUTINES CALLED-
019519,000026: 
019520,000027:                                                                                                 #  GOPERF4
019521,000028:                                                                                                 #  GOFLASH
019522,000029:                                                                                                 #  THISPREC
019523,000030:                                                                                                 #  OTHPREC
019524,000031:                                                                                                 #  LAT-LONG
019525,000032:                                                                                                 #  NORMAL EXIT MODES-
019526,000033: 
019527,000034:                                                                                                 #  ASTRONAUT REQUEST THROUGH DSKY TO TERMINATE PROGRAM V34E
019528,000035:                                                                                                 #  ALARM OR ABORT EXIT MODES-
019529,000036: 
019530,000037:                                                                                                 #  NONE
019531,000038:                                                                                                 #  OUTPUT-
019532,000039: 
019533,000040:                                                                                                 #  OCTAL DISPLAY OF OPTION CODE AND VEHICLE WHOSE GROUND TRACK IS TO BE
019534,000041:                                                                                                 #  COMPUTED
019535,000042:                                                                                                 #            OPTION CODE  00002
019536,000043:                                                                                                 #            THIS         00001
019537,000044:                                                                                                 #            OTHER        00002
019538,000045:                                                                                                 #  DECIMAL DISPLAY OF TIME TO BE INTEGRATED TO HOURS , MINUTES , SECONDS
019539,000046:                                                                                                 #  DECIMAL DISPLAY OF LAT,LONG,ALT
019540,000047:                                                                                                 #  ERASABLE INITIALIZATION REQUIRED
019541,000048: 
019542,000049:                                                                                                 #  AX0      2DEC   4.652459653 E-5   RADIANS       $68-69 CONSTANTS"
019543,000050: 
019544,000051:                                                                                                 #  -AY0     2DEC   2.147535898 E-5   RADIANS
019545,000052: 
019546,000053:                                                                                                 #  AZ0      2DEC   .7753206164       REVOLUTIONS
019547,000054:                                                                                                 #  FOR LUNAR ORBITS 504LM VECTOR IS NEEDED
019548,000055: 
019549,000056:                                                                                                 #  504LM    2DEC   -2.700340600 E-5  RADIANS
019550,000057: 
019551,000058:                                                                                                 #  504LM _2 2DEC   -7.514128400 E-4  RADIANS
019552,000059: 
019553,000060:                                                                                                 #  504LM _4 2DEC   _2.553198641 E-4  RADIANS
019554,000061: 
019555,000062:                                                                                                 #         NONE
019556,000063:                                                                                                 #  DEBRIS
019557,000064:                                                                                                 # # Page 448
019558,000065: 
019559,000066:                                                                                                 #  CENTRALS-A,Q,L
019560,000067:                                                                                                 #  OTHER-THOSE USED BY THE ABOVE LISTED SUBROUTINES
019561,000068:                                                                                                 #  SEE LEMPREC,LAT-LONG
019562,000069: ???????  30,2000                                 SBANK=   LOWSUPER                              #  FOR LOW 2CADR'S.
019563,000070: 
019564,000071: 33,3773                                          BANK     33                                    
019565,000072: 37,2000                                          SETLOC   P20S                                  
019566,000073: 37,2000                                          BANK                                           
019567,000074: 
019568,000075: 37,2001  E4,1715                                 EBANK=   P21TIME                               
019569,000076: 37,2001                                          COUNT    24/P21                                
019570,000077: 
019571,000078: 37,2001           34712        PROG21            CAF      ONE                                   
019572,000079: 37,2002           55132                          TS       OPTION2                               #  ASSUMED VEHICLE IS LM , R2 = 00001
019573,000080: 37,2003           34711                          CAF      BIT2                                  #   OPTION 2
019574,000081: 37,2004           04555                          TC       BANKCALL                              
019575,000082: 37,2005           20761                          CADR     GOPERF4                               
019576,000083: 37,2006           04106                          TC       GOTOPOOH                              #  TERMINATE
019577,000084: 37,2007           02011                          TC       +2                                    #  PROCEED VALUE OF ASSUMED VEHICLE OK
019578,000085: 37,2010           02003                          TC       -5                                    #  R2 LOADED THROUGH DSKY
019579,000086: 37,2011           32102        P21PROG1          CAF      V6N34                                 #  LOAD DESIRED TIME OF LAT-LONG.
019580,000087: 37,2012           04555                          TC       BANKCALL                              
019581,000088: 37,2013           20624                          CADR     GOFLASH                               
019582,000089: 37,2014           04106                          TC       GOTOPOOH                              #  TERM
019583,000090: 37,2015           02017                          TC       +2                                    #  PROCEED VALUES OK
019584,000091: 37,2016           02011                          TC       -5                                    #  TIME LOADED THROUGH DSKY
019585,000092: 37,2017           06006                          TC       INTPRET                               
019586,000093: 37,2020           77745                          DLOAD                                          
019587,000094: 37,2021           01046                                   DSPTEM1                               
019588,000095: 37,2022           02316                          STORE    P21TIME                               
019589,000096: 37,2023           45335                          SLOAD    DSU                                   
019590,000097: 37,2024           01133                                   OPTION2                               
019591,000098: 37,2025           36100                                   P21ONENN                              
019592,000099: 37,2026           71230                          BHIZ     DLOAD                                 
019593,000100: 37,2027           76042                                   P21PROG2                              #  VEHICLE TO BE INTEGRATED IS LEM
019594,000101: 37,2030           02316                                   P21TIME                               #  VEHICLE TO BE INTEGRATED IS CSM
019595,000102: 37,2031           34041                          STCALL   TDEC1                                 #  INTEGRATE TO TIME SPECIFIED IN TDEC
019596,000103: 37,2032           27036                                   OTHPREC                               #  ADJUST UNITS FOR LAT-LONG ROUTINE
019597,000104: 37,2033           46135        P21PROGA          SLOAD    BHIZ                                  
019598,000105: 37,2034           00050                                   X2                                    
019599,000106: 37,2035           76050                                   P21PROG3                              
019600,000107: 37,2036           43175                          VLOAD    SETGO                                 
019601,000108: 37,2037           00001                                   RATT                                  
019602,000109: 37,2040           01423                                   LUNAFLAG                              
019603,000110: 37,2041           76053                                   P21PROG4                              
019604,000111: 37,2042           77745        P21PROG2          DLOAD                                          
019605,000112: 37,2043           02316                                   P21TIME                               
019606,000113: 37,2044           34041                          STCALL   TDEC1                                 
019607,000114: 37,2045           27022                                   THISPREC                              
019608,000115:                                                                                                 # # Page 449
019609,000116: 37,2046           77650                          GOTO                                           
019610,000117: 37,2047           76033                                   P21PROGA                              
019611,000118: 37,2050           43175        P21PROG3          VLOAD    CLEAR                                 
019612,000119: 37,2051           00001                                   RATT                                  
019613,000120: 37,2052           01663                                   LUNAFLAG                              
019614,000121: 37,2053           16152        P21PROG4          STODL    ALPHAV                                
019615,000122: 37,2054           00015                                   TAT                                   
019616,000123: 37,2055           45014                          CLEAR    CALL                                  
019617,000124: 37,2056           00662                                   ERADFLAG                              
019618,000125: 37,2057           26322                                   LAT-LONG                              
019619,000126: 37,2060           77776                          EXIT                                           
019620,000127: 37,2061           32101                          CAF      V06N43                                #  DISPLAY LAT,LONG,ALT
019621,000128: 37,2062           04555                          TC       BANKCALL                              #  LAT,LONG = 1/2 REVS B0
019622,000129: 37,2063           20624                          CADR     GOFLASH                               #  ALT = KM  B14
019623,000130: 37,2064           04106                          TC       GOTOPOOH                              #  TERM
019624,000131: 37,2065           04106                          TC       GOTOPOOH                              
019625,000132: 37,2066           06006                          TC       INTPRET                               #  V32E RECYCLE
019626,000133: 37,2067           43345                          DLOAD    DAD                                   
019627,000134: 37,2070           02316                                   P21TIME                               
019628,000135: 37,2071           36076                                   600SEC                                #  600 SECONDS OR 10 MIN
019629,000136: 37,2072           01046                          STORE    DSPTEM1                               
019630,000137: 37,2073           77634                          RTB                                            
019631,000138: 37,2074           76011                                   P21PROG1                              
019632,000139: 
019633,000140: 37,2075           00003 25140  600SEC            2DEC     60000      B-28                       #  10 MIN
019634,000141: 37,2077           00001        P21ONENN          OCT      00001                                 #  NEEDED TO DETERMINE VEHICLE
019635,000142: 37,2100           00000                          OCT      00000                                 #  TO BE INTEGRATED
019636,000143: 37,2101           01453        V06N43            VN       00643                                 
019637,000144: 37,2102           01442        V6N34             VN       00634                                 

End of include-file GROUND_TRACKING_DETERMINATION_PROGRAM_-_P21.agc.  Parent file is MAIN.agc