Assembly listing generated by yaYUL

Source Code

These source-code files are part of a reconstructed copy of Luminary 69/2, the flown, final release of the Apollo 10 Lunar Module (LM) Apollo Guidance Computer (AGC) software.

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".

Comments from 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 the Virtual AGC project's GitHub repository.

047257,000002:                                                                                                  ## Copyright:   Public domain.
047258,000003:                                                                                                  ## Filename:    SINGLE_PRECISION_SUBROUTINES.agc
047259,000004:                                                                                                  ## Purpose:     A section of LUM69 revision 2.
047260,000005:                                                                                                  ##              It is part of the reconstructed source code for the flown
047261,000006:                                                                                                  ##              version of the flight software for the Lunar Module's (LM)
047262,000007:                                                                                                  ##              Apollo Guidance Computer (AGC) for Apollo 10. The code has
047263,000008:                                                                                                  ##              been recreated from a copy of Luminary revsion 069, using
047264,000009:                                                                                                  ##              changes present in Luminary 099 which were described in
047265,000010:                                                                                                  ##              Luminary memos 75 and 78. The code has been adapted such
047266,000011:                                                                                                  ##              that the resulting bugger words exactly match those specified
047267,000012:                                                                                                  ##              for LUM69 revision 2 in NASA drawing 2021152B, which gives
047268,000013:                                                                                                  ##              relatively high confidence that the reconstruction is correct.
047269,000014:                                                                                                  ## Reference:   p.  1097
047270,000015:                                                                                                  ## Assembler:   yaYUL
047271,000016:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
047272,000017:                                                                                                  ## Website:     www.ibiblio.org/apollo/index.html
047273,000018:                                                                                                  ## Mod history: 2019-07-27 MAS  Created from Luminary 69.
047274,000019:

Page 1097

 047276,000021:    5032 047277,000022: 047278,000023: 047279,000024: 047280,000025:    5032 < < 047283,000028:    5034 047284,000029:    5035 047285,000030: 047286,000031:    5037 047287,000032:    5040 047288,000033:    5041 047289,000034:    5042 047290,000035:    5043 047291,000036:    5044 047292,000037:    5045 047293,000038:    5046 047294,000039:    5047 047295,000040:    5050 < 047311,000056:    5070 047312,000057:    5071 047313,000058: 047314,000059:

End of include-file

BLOCK 02 # SINGLE PRECISION SINE AND COSINE COUNT* $$/INTER /a>047281,000026: 5032 64736 SPCOS AD HALF # ARGUMENTS SCALED AT PI /a>047282,000027: 5033 55076 SPSIN TS TEMK 15036 TCF SPT 41076 CS TEMK 5036 60000 SPT DOUBLE 55076 TS TEMK 15051 TCF POLLEY 57076 XCH TEMK 51076 INDEX TEMK 64734 AD LIMITS 40000 COM 61076 AD TEMK 55076 TS TEMK 15051 TCF POLLEY 15067 TCF ARG90 >047296,000041: 5051 00006 POLLEY EXTEND 71076 MP TEMK 55077 TS SQ 00006 EXTEND 75005 MP C5/2 67736 AD C3/2 00006 EXTEND 71077 MP SQ 67716 AD C1/2 00006 EXTEND 71076 MP TEMK 20001 DDOUBL 55076 TS TEMK 00002 TC Q /a>047310,000055: 5067 50000 ARG90 INDEX A 44734 CS LIMITS 00002 TC Q # RESULT SCALED AT 1 SINGLE_PRECISION_SUBROUTINES.agc. Parent file is MAIN.agc