Source Code

These source-code 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 A scan by Ron Burkey has superceded it, made from a more-legible copy from the collection of original AGC developer Fred Martin.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.

019534,000002:                                                                                                  ## Copyright:   Public domain.
019535,000003:                                                                                                  ## Filename:    GROUND_TRACKING_DETERMINATION_PROGRAM.agc
019536,000004:                                                                                                  ## Purpose:     Part of the source code for Colossus, build 249.
019537,000005:                                                                                                  ##              It is part of the source code for the Command Module's (CM)
019538,000006:                                                                                                  ##              Apollo Guidance Computer (AGC), possibly for Apollo 8 and 9.
019539,000007:                                                                                                  ## Assembler:   yaYUL
019540,000008:                                                                                                  ## Reference:   pp. 451-453 of 1701.pdf.
019541,000009:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
019542,000010:                                                                                                  ## Website:     www.ibiblio.org/apollo.
019543,000011:                                                                                                  ## Mod history: 08/11/04 RSB.   Began transcribing.
019544,000012:                                                                                                  ##
019545,000013:                                                                                                  ## The contents of the "Colossus249" files, in general, are transcribed 
019546,000014:                                                                                                  ## from a scanned document obtained from MIT's website,
019547,000015:                                                                                                  ## http://hrst.mit.edu/hrs/apollo/public/archive/1701.pdf.  Notations on this
019548,000016:                                                                                                  ## document read, in part:
019549,000017:                                                                                                  ##
019550,000018:                                                                                                  ##      Assemble revision 249 of AGC program Colossus by NASA
019551,000019:                                                                                                  ##      2021111-041.  October 28, 1968.  
019552,000020:                                                                                                  ##
019553,000021:                                                                                                  ##      This AGC program shall also be referred to as
019554,000022:                                                                                                  ##                              Colossus 1A
019555,000023:                                                                                                  ##
019556,000024:                                                                                                  ##      Prepared by
019557,000025:                                                                                                  ##                      Massachusetts Institute of Technology
019558,000026:                                                                                                  ##                      75 Cambridge Parkway
019559,000027:                                                                                                  ##                      Cambridge, Massachusetts
019560,000028:                                                                                                  ##      under NASA contract NAS 9-4065.
019561,000029:                                                                                                  ##
019562,000030:                                                                                                  ## Refer directly to the online document mentioned above for further information.
019563,000031:                                                                                                  ## Please report any errors (relative to 1701.pdf) to info@sandroid.org.
019564,000032:                                                                                                  ##
019565,000033:                                                                                                  ## In some cases, where the source code for Luminary 131 overlaps that of 
019566,000034:                                                                                                  ## Colossus 249, this code is instead copied from the corresponding Luminary 131
019567,000035:                                                                                                  ## source file, and then is proofed to incorporate any changes.
019568,000036: 

Page 451

019570,000038:                                                                                                  #  GROUND TRACKING DETERMINATION PROGRAM -- P21
019571,000039: 
019572,000040:                                                                                                  #  PROGRAM DESCRIPTION
019573,000041:                                                                                                  #        MOD NO -- 1
019574,000042:                                                                                                  #        MOD BY -- N. M. NEVILLE
019575,000043: 
019576,000044:                                                                                                  #  FUNCTIONAL DESCRIPTION --
019577,000045:                                                                                                  #        TO PROVIDE THE ASTRONAUT DETAILS OF THE LM OR CSM GROUND TRACK WITHOUT
019578,000046:                                                                                                  #        THE NEED FOR GROUND COMMUNICATION (REQUESTED BY DSKY).
019579,000047: 
019580,000048:                                                                                                  #  CALLING SEQUENCE --
019581,000049:                                                                                                  #        ASTRONAUT REQUEST THROUGH DSKY V37E21E
019582,000050: 
019583,000051:                                                                                                  #  SUBROUTINES CALLED --
019584,000052:                                                                                                  #        GOPERF4
019585,000053:                                                                                                  #        GOFLASH
019586,000054:                                                                                                  #        THISPREC
019587,000055:                                                                                                  #        OTHPREC
019588,000056:                                                                                                  #        LAT-LONG
019589,000057: 
019590,000058:                                                                                                  #  NORMAL EXIT MODES --
019591,000059:                                                                                                  #        ASTRONAUT REQUEST THROUGH DSKY TO TERMINATE PROGRAM V34E
019592,000060: 
019593,000061:                                                                                                  #  ALARM OR ABORT EXIT MODES --
019594,000062:                                                                                                  #        NONE
019595,000063: 
019596,000064:                                                                                                  #  OUTPUT --
019597,000065:                                                                                                  #        OCTAL DISPLAY OF OPTION CODE AND VEHICLE WHOSE GROUND TRACK IS TO BE
019598,000066:                                                                                                  #        COMPUTED
019599,000067:                                                                                                  #                OPTION CODE     00002
019600,000068:                                                                                                  #                THIS            00001
019601,000069:                                                                                                  #                OTHER           00002
019602,000070:                                                                                                  #        DECIMAL DISPLAY OF TIME TO BE INTEGRATED TO HOURS, MINUTES, SECONS
019603,000071:                                                                                                  #        DECIMAL DISPLAY OF LAT,LONG,ALT
019604,000072: 
019605,000073:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED
019606,000074:                                                                                                  #        AX0     2DEC    4.652459653 E-5 RADIANS
019607,000075:                                                                                                  #        -AY0    2DEC    2.147535898 E-5 RADIANS
019608,000076:                                                                                                  #        AZ0     2DEC    .7753206164     REVOLUTIONS
019609,000077:                                                                                                  #        FOR LUNAR ORBITS 504LM VECTOR IS NEEDED:
019610,000078:                                                                                                  #        504LM   2DEC    -2.700340600 E-5 RADIANS
019611,000079:                                                                                                  #        504LM+2 2DEC    -7.514128400 E-4 RADIANS
019612,000080:                                                                                                  #        504LM+4 2DEC     2.553198641 E-4 RADIANS
019613,000081:                                                                                                  #        NONE
019614,000082: 
019615,000083:                                                                                                  #  DEBRIS

Page 452

019617,000085:                                                                                                  #        CENTRALS -- A,Q,L
019618,000086:                                                                                                  #        OTHER -- THOSE USED BY THE ABOVE LISTED SUBROUTINES
019619,000087:                                                                                                  #        SEE LEMPREC, LAT-LONG
019620,000088: 
019621,000089: 33,3772  30,2000                                  SBANK=   LOWSUPER                              #  FOR LOW 2CADR'S.
019622,000090: 
019623,000091: 33,3772                                           BANK     33                                    
019624,000092: 37,2000                                           SETLOC   P20S                                  
019625,000093: 37,2000                                           BANK                                           
019626,000094: 
019627,000095: 37,2001  E4,1715                                  EBANK=   P21TIME                               
019628,000096: 37,2001                                           COUNT    24/P21                                
019629,000097: 
019630,000098: 37,2001           34712        PROG21             CAF      ONE                                   
019631,000099: 37,2002           55132                           TS       OPTION2                               #  ASSUMED VEHICLE IS LM, R2 = 00001
019632,000100: 37,2003           34711                           CAF      BIT2                                  #  OPTION 2
019633,000101: 37,2004           04555                           TC       BANKCALL                              
019634,000102: 37,2005           20761                           CADR     GOPERF4                               
019635,000103: 37,2006           04106                           TC       GOTOP00H                              #  TERMINATE
019636,000104: 37,2007           02011                           TC       +2                                    #  PROCEED VALUE OF ASSUMED VEHICLE OK
019637,000105: 37,2010           02003                           TC       -5                                    #  R2 LOADED THROUGH DSKY
019638,000106: 37,2011           32102        P21PROG1           CAF      V6N34                                 #  LOAD DESIRED TIME OF LAT-LONG.
019639,000107: 37,2012           04555                           TC       BANKCALL                              
019640,000108: 37,2013           20624                           CADR     GOFLASH                               
019641,000109: 37,2014           04106                           TC       GOTOP00H                              #  TERM
019642,000110: 37,2015           02017                           TC       +2                                    #  PROCEED VALUES OK
019643,000111: 37,2016           02011                           TC       -5                                    #  TIME LOADED THROUGH DSKY
019644,000112: 37,2017           06006                           TC       INTPRET                               
019645,000113: 37,2020           77745                           DLOAD                                          
019646,000114: 37,2021           01046                                    DSPTEM1                               
019647,000115: 37,2022           02316                           STORE    P21TIME                               
019648,000116: 37,2023           45335                           SLOAD    DSU                                   
019649,000117: 37,2024           01133                                    OPTION2                               
019650,000118: 37,2025           36100                                    P21ONENN                              
019651,000119: 37,2026           71230                           BHIZ     DLOAD                                 
019652,000120: 37,2027           76042                                    P21PROG2                              #  VEHICLE TO BE INTEGRATED IS LEM
019653,000121: 37,2030           02316                                    P21TIME                               #  VEHICLE TO BE INTEGRATED IS CSM
019654,000122: 37,2031           34041                           STCALL   TDEC1                                 #  INTEGRATE TO TIME SPECIFIED IN TDEC1
019655,000123: 37,2032           27036                                    OTHPREC                               #  ADJUST UNITS FOR LAT-LONG ROUTINE
019656,000124: 37,2033           46135        P21PROGA           SLOAD    BHIZ                                  
019657,000125: 37,2034           00050                                    X2                                    
019658,000126: 37,2035           76050                                    P21PROG3                              
019659,000127: 37,2036           43175                           VLOAD    SETGO                                 
019660,000128: 37,2037           00001                                    RATT                                  
019661,000129: 37,2040           01423                                    LUNAFLAG                              
019662,000130: 37,2041           76053                                    P21PROG4                              
019663,000131: 37,2042           77745        P21PROG2           DLOAD                                          
019664,000132: 37,2043           02316                                    P21TIME                               
019665,000133: 37,2044           34041                           STCALL   TDEC1                                 
019666,000134: 37,2045           27022                                    THISPREC                              

Page 453

019668,000136: 37,2046           77650                           GOTO                                           
019669,000137: 37,2047           76033                                    P21PROGA                              
019670,000138: 37,2050           43175        P21PROG3           VLOAD    CLEAR                                 
019671,000139: 37,2051           00001                                    RATT                                  
019672,000140: 37,2052           01663                                    LUNAFLAG                              
019673,000141: 37,2053           16152        P21PROG4           STODL    ALPHAV                                
019674,000142: 37,2054           00015                                    TAT                                   
019675,000143: 37,2055           45014                           CLEAR    CALL                                  
019676,000144: 37,2056           00662                                    ERADFLAG                              
019677,000145: 37,2057           26322                                    LAT-LONG                              
019678,000146: 37,2060           77776                           EXIT                                           
019679,000147: 37,2061           32101                           CAF      V06N43                                #  DISPLAY LAT,LONG,ALT
019680,000148: 37,2062           04555                           TC       BANKCALL                              #  LAT,LONG = 1/2 REVS B0
019681,000149: 37,2063           20624                           CADR     GOFLASH                               #  ALT = KM B14
019682,000150: 37,2064           04106                           TC       GOTOP00H                              #  TERM
019683,000151: 37,2065           04106                           TC       GOTOP00H                              
019684,000152: 37,2066           06006                           TC       INTPRET                               #  V32E RECYCLE
019685,000153: 37,2067           43345                           DLOAD    DAD                                   
019686,000154: 37,2070           02316                                    P21TIME                               
019687,000155: 37,2071           36076                                    600SEC                                #  600 SECONDS OR 10 MIN
019688,000156: 37,2072           01046                           STORE    DSPTEM1                               
019689,000157: 37,2073           77634                           RTB                                            
019690,000158: 37,2074           76011                                    P21PROG1                              
019691,000159: 
019692,000160: 37,2075           00003 25140  600SEC             2DEC     60000      B-28                       #  10 MIN
019693,000161: 37,2077           00001        P21ONENN           OCT      00001                                 #  NEEDED TO DETERMINE VEHICLE
019694,000162: 37,2100           00000                           OCT      00000                                 #  TO BE INTEGRATED
019695,000163: 
019696,000164: 37,2101           01453        V06N43             VN       00643                                 
019697,000165: 37,2102           01442        V6N34              VN       00634                                 
019698,000166: 

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