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These source-code files are part of a reconstructed copy of Comanche 44, the
initial release (though not the final mission release) of the Apollo 10 
Command Module (CM) Apollo Guidance Computer (AGC) software.  Subsequent releases
were Comanche 45 and Comanche 45/2 (the flown release on Apollo 10). The reconstruction
is believed to be exactly accurate, but in the absence of an actual Apollo-era
listing of Comanche 44, some explanation of the reconstruction process is needed
to insure confidence in that accuracy. 
<br><br>
The starting point was the source code of Comanche 51 
(separately previously reconstructed from an Apollo-era listing of Comanche 55, 
flown on Apollo 11).  Comanche 51 source code was then modified 
by undoing changes known to have been made between revisions 44 and 51. The now-reconstructed 
Comanche 44 source code was verified by assembling it and checking that the assembled code had
the expected known-correct memory-bank checksums. 
Note that page numbers in the reconstructed code match those on the Comanche 55 printout,
although the source code would likely have different page numbers in a contemporary
Comanche 44 listing.
<br><br>
Annotations that were not present in the contemporary source code have been added to the reconstructed
code to justify each change relative to Comanche 51. Here's a guide to the Apollo documentation referenced
in those annotations:<br>
<ul>
<li><a href="https://archive.org/stream/apertureCardBox467Part2NARASW_images#page/n89/mode/1up">
    MIT/IL engineering drawing 2021153D, sheet 3</a>.  Listing of the memory-bank 
    checksums for Comanche 44.</li>
<li><a href="https://archive.org/details/Comanche55J2k60">
       Comanche 55 (Apollo 11 CM final release) assembly listing</a>.</li>
<li><a href="http://www.ibiblio.org/apollo/listings/Comanche051/MAIN.agc.html">
       Reconstructed Comanche 51 (Apollo 11 CM initial release) assembly listing</a>.</li>
<li><a href="https://archive.org/details/Colossus249MartinPp15651719">
       Colossus 249 (Apollo 9 CM final release) assembly listing</a>.</li>
<li><a href="http://www.ibiblio.org/apollo/Documents/HSI-208454.pdf#page=12">
       <i>Guidance System Operations Plan for Colossus 3</i>, Section 5, p. <i>xiii</i></a>.  
       Table listing some Program Request Changes (PCRs) incorporated between 
       Comanche 45/2 and Comanche 55.</li>
<li><a href="http://www.ibiblio.org/apollo/Documents/HSI-208472.pdf#page=8">
       <i>Guidance System Operations Plan for Colossus 2E</i>, Section 3, pp. <i>ix-x</i></a>.
       Tables listing some Program Change Requests (PCRs) incorporated between 
       Comanche 44 and Comanche 55.</li>
<li><a href="http://www.ibiblio.org/apollo/links.html#PGE_COLOSSUS2">
       <i>Programmed Guidance Equations for Colossus 2, Based on Comanche 55</i></a>. 
       Provides a pseudocode representation of portions of Comanche 55, showing change bars.
       The software revisions <i>from which</i> and <i>to which</i> the changes occurred
       are indicated by the markings next to the document page number:
       <ul>
       <li>"Rev. 0" pages:  change bars are from Colossus 249 to Comanche 45</li>
       <li>"Rev. 1" pages:  change bars are from Comanche 45 to Comanche 45/2</li>
       <li>"Rev. 2" pages:  change bars are from Comanche 45/2 to Comanche 55</li>
       </ul>
       </li>
</ul>
In most cases, only the titles (rather than the full texts) of PCRs are known.  In addition to the 
explanatory annotations, there is also 
<a href="https://github.com/virtualagc/virtualagc/issues/1134">
a step-by-step commentary about the reconstruction process</a>.
<br><br>
Comments expected to have been present in the original source code are prefixed with a single '#' symbol, 
whereas comments added later are prefixed by "##" or "###".  Report any errors 
noted by creating an 
issue report at <a href="https://github.com/rburkey2005/virtualagc/issues">the Virtual AGC
Project's GitHub repository</a>.
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