The reconstruction is based on the source code of Luminary 69 — i.e., the initial, unflown version, "revision 0" — of which a contemporary listing was available. The code was then updated by incorporating the differences between Luminary 69 and Luminary 69/2, known from other contemporary documentation. The only such difference is the implementation in Luminary 69/2 of the "R-2 Lunar Potential Model", the source code for which was taken from program Luminary 99/1 (Apollo 11 LM), of which a contemporary listing was also available. Finally, the now-reconstructed Luminary 69/2 was then validated by assembling it to executable form and verifying that its memory banks had the correct checksums, known from still other contemporary documentation.
Note that page numbers in the reconstructed code match those in the original Luminary 69 program listing, or in the ORBITAL INTEGRATION log section, in Luminary 99/1. Page numbers would certainly differ somewhat in a contemporary Luminary 69/2 listing. Moreover, annotations that were not present in the contemporary source code have been added to the reconstructed code to justify each change in Luminary 69/2 relative to Luminary 69. Here's a guide to the Apollo documentation referenced in those annotations:
- MIT/IL engineering drawing 2021152N, sheet 3. Listing of the memory-bank checksums for Luminary 69/2 (called "LUMINARY 69 REV. 2" in the document itself).
- Luminary 99/1 (Apollo 11 LM final release) assembly listing.
- Luminary 69 (Apollo 10 LM initial release) assembly listing.
- LUMINARY Memo #75, "R-2 Lunar Potential Model Added to LUM".
- LUMINARY Memo #78, "LUMINARY Revisions 93-96".