Source Code

This source code is very close to the Apollo Guidance Computer software for the Apollo 13 Lunar module. This revision of the Luminary 131 program is from December of 1969, whereas there was a later revision in January of 1970, and still another revision in February, which is the code that flew on the mission. As far as this transcription is concerned, it was originally from a copy made in 1991 of a printout from the collection of AGC developer Don Eyles for collector David Craig. It was subsequently scanned by Gary Neff, reprocessed for online presentation at the now-discontinued History of Recent Science and Technology (HRST) website of MIT's Dibner Institute (the full-quality scans being discarded in the process), and finally transcribed by Ron Burkey for the Virtual AGC Project. Although a high-quality replacement scan for a completely illegible page was later provided by Gary Neff, the reduced legibility of the reprocessed HRST posting nevertheless caused many errors to be introduced into the transcription. Accordingly, a second scan of the same physical printout was made in 2017 for the Virtual AGC Project's collection at the Internet Archive, and used to correct the transcription errors. All of the scanned materials mentioned, as well as other Luminary 131 related material, are available online. Don Eyles apprently made additional hand-written notes in printout between 1991 and 2017, so the two scans are not identical in that respect. The page-headings in the printout read, in part:
	GAP:  ASSEMBLE REVISION 131 OF AGC PROGRAM LUMINARY BY NASA 2021112-091
	17:53 DEC. 19, 1969
Note that the date is the date the printout was made, not the date on which the program revision was released, although these happen to be very close together.

046003,000002:                                                                                                  ## Copyright:   Public domain.
046004,000003:                                                                                                  ## Filename:    INTERPRETIVE_CONSTANT.agc
046005,000004:                                                                                                  ## Purpose:     A section of Luminary 1C, revision 131.
046006,000005:                                                                                                  ##              It is part of the source code for the Lunar Module's (LM)
046007,000006:                                                                                                  ##              Apollo Guidance Computer (AGC) for Apollo 13.
046008,000007:                                                                                                  ##              This file is intended to be a faithful transcription, except
046009,000008:                                                                                                  ##              that the code format has been changed to conform to the
046010,000009:                                                                                                  ##              requirements of the yaYUL assembler rather than the
046011,000010:                                                                                                  ##              original YUL assembler.
046012,000011:                                                                                                  ## Reference:   pp. 1094-1095
046013,000012:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
046014,000013:                                                                                                  ## Website:     www.ibiblio.org/apollo/index.html
046015,000014:                                                                                                  ## Mod history: 05/31/03 RSB.   Began transcribing.
046016,000015:                                                                                                  ##              05/14/05 RSB    Corrected website reference above
046017,000016:                                                                                                  ##              2017-01-06 RSB  Page numbers now agree with those on the
046018,000017:                                                                                                  ##                              original harcopy, as opposed to the PDF page
046019,000018:                                                                                                  ##                              numbers in 1701.pdf.
046020,000019:                                                                                                  ##              2017-02-27 RSB  Proofed comment text using octopus/ProoferComments.
046021,000020: 

Page 1094

046023,000022: 23,2000                                           SETLOC   INTPRET1                              
046024,000023: 23,2000                                           BANK                                           
046025,000024: 
046026,000025: 23,2513                                           COUNT*   $$/ICONS                              
046027,000026: 23,2513           10000 00000  DP1/4TH            2DEC     .25                                   
046028,000027: 23,2515           00000 00000  UNITZ              2DEC     0          B-28                       
046029,000028: 23,2517           00000 00000  UNITY              2DEC     0          B-28                       
046030,000029: 23,2521           20000 00000  UNITX              2DEC     .5                                    
046031,000030: 23,2523           00000 00000  ZEROVECS           2DEC     0          B-28                       
046032,000031: 23,2525           00000 00000                     2DEC     0          B-28                       
046033,000032: 23,2527           00000 00000                     2DEC     0          B-28                       
046034,000033: 
046035,000034: 23,2531  23,2521               DPHALF             =        UNITX                                 
046036,000035: 23,2531           37777        DPPOSMAX           OCT      37777                                 
046037,000036: 23,2532           37777                           OCT      37777                                 
046038,000037: 

Page 1095

046040,000039:                                                                                                  #  INTERPRETIVE CONSTANTS IN THE OTHER HALF-MEMORY
046041,000040: 
046042,000041: 12,2000                                           SETLOC   INTPRET2                              
046043,000042: 12,2000                                           BANK                                           
046044,000043: 
046045,000044: 12,2000                                           COUNT*   $$/ICONS                              
046046,000045: 12,2000           00000 00000  ZUNIT              2DEC     0          B-28                       
046047,000046: 12,2002           00000 00000  YUNIT              2DEC     0          B-28                       
046048,000047: 12,2004           20000 00000  XUNIT              2DEC     .5                                    
046049,000048: 12,2006           00000 00000  ZEROVEC            2DEC     0          B-28                       
046050,000049: 12,2010           00000 00000                     2DEC     0          B-28                       
046051,000050: 12,2012           00000 00000                     2DEC     0          B-28                       
046052,000051: 
046053,000052: 12,2014           77777                           OCT      77777                                 #  -0, -6, -12 MUST REMAIN IN THIS ORDER
046054,000053: 12,2015           77771        DFC-6              DEC      -6         B-14                       
046055,000054: 12,2016           77763        DFC-12             DEC      -12        B-14                       
046056,000055: 12,2017           37777 37777  LODPMAX            2OCT     3777737777                            #  THESE TWO CONSTANTS MUST REMAIN
046057,000056: 12,2021           37777 37777  LODPMAX1           2OCT     3777737777                            #  ADJACENT AND THE SAME FOR INTEGRATION
046058,000057: 
046059,000058: 12,2023  12,2006               ZERODP             =        ZEROVEC                               
046060,000059: 12,2023  12,2004               HALFDP             =        XUNIT                                 
046061,000060: 
046062,000061: 

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