Source Code
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These source-code files are part of a reconstructed copy of Comanche 51, the
initial release (though not the final mission release) of the Apollo 11
Command Module (CM) Apollo Guidance Computer (AGC) software. The flown, final
release was Comanche 55. The reconstruction is believed to be exactly accurate,
but in the absence of an actual Apollo-era listing of Comanche 51, some
explanation of the reconstruction process is needed to insure confidence in
that accuracy.
The starting point was the source code of Comanche 55, whose original source code
is available. Comanche 55 source code was then modified by undoing changes known
to have been made between revisions 51 and 55. The most-significant steps involved
reverting changes related to the R-2 lunar potential model, the details of which
were known from the previous, separate, independent reconstruction of the Apollo 10
Lunar Module software Luminary 69/2. The now-reconstructed
Comanche 51 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 or Luminary 69 printouts, although
the source code would likely have different page numbers in a contemporary Comanche 51 listing.
Annotations that were not present in the contemporary source code have been added to
the reconstructed code to justify each change relative to Comanche 55. Here's a guide
to some of the Apollo documentation relevant to those annotations:
Among documentation not actually referenced in the annotations, there is
a short writeup about the reconstruction process in our software repository
that may be helpful in understanding it from a different perspective. There's also
a handy table
that lists what the number of memory-words should be for each routine in Comanche 51,
which could make a nice double-check; however, we've not performed that double-check ourselves.
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 the Virtual AGC
Project's GitHub repository.
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018033,000002: ## Copyright: Public domain.
018034,000003: ## Filename: SYSTEM_TEST_STANDARD_LEAD_INS.agc
018035,000004: ## Purpose: A section of Comanche revision 051.
018036,000005: ## It is part of the reconstructed source code for the
018037,000006: ## original release of the flight software for the Command
018038,000007: ## Module's (CM) Apollo Guidance Computer (AGC) for Apollo 11.
018039,000008: ## The code has been recreated from a copy of Comanche 055. It
018040,000009: ## has been adapted such that the resulting bugger words
018041,000010: ## exactly match those specified for Comanche 51 in NASA drawing
018042,000011: ## 2021153D, which gives relatively high confidence that the
018043,000012: ## reconstruction is correct.
018044,000013: ## Reference: pp. 420-422
018045,000014: ## Assembler: yaYUL
018046,000015: ## Contact: Ron Burkey <info@sandroid.org>.
018047,000016: ## Website: www.ibiblio.org/apollo/index.html
018048,000017: ## Mod history: 2019-07-30 MAS Created from Comanche 55.
018049,000018:
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Page 420
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018051,000020: 22,3151 E5,1671 EBANK= XSM
018052,000021:
018053,000022: 33,2000 BANK 33
018054,000023: 13,2000 SETLOC E/PROG1
018055,000024: 13,2000 BANK
018056,000025:
018057,000026: 13,2036 COUNT* $$/P07
018058,000027:
018059,000028: # SPECIAL PROGRAMS TO EASE THE PANGS OF ERASABLE MEMORY PROGRAMS.
018060,000029:
018061,000030: # E/BKCALL FOR DOING BANKCALLS FROM AND RETURNING TO ERASABLE.
018062,000031:
018063,000032: # THIS ROUTINE IS CALLABLE FROM ERASABLE OR FIXED. LIKE BANKCALL, HOWEVER, SWITCHING BETWEEN S3 AND S4
018064,000033: # IS NOT POSSIBLE.
018065,000034:
018066,000035: # THE CALLING SEQUENCE IS:
018067,000036:
018068,000037: # TC BANKCALL
018069,000038: # CADR E/BKCALL
018070,000039: # CADR ROUTINE WHERE YOU WANT TO GO IN FIXED.
018071,000040: # RETURN HERE FROM DISPLAY TERMINATE, BAD STALL OR TC Q.
018072,000041: # RETURN HERE FROM DISPLAY PROCEED OR GOOD RETURN FROM STALL.
018073,000042: # RETURN HERE FROM DISPLAY ENTER OR RECYCLE.
018074,000043:
018075,000044: # THIS ROUTINE REQUIRES TWO ERASABLES (EBUF2, +1) IN UNSWITCHED WHICH ARE UNSHARED BY INTERRUPTS AND
018076,000045: # OTHER EMEMORY PROGRAMS.
018077,000046:
018078,000047: # A + L ARE PRESERVED THROUGH BANKCALL AND E/BKCALL.
018079,000048:
018080,000049: 13,2036 52134 E/BKCALL DXCH BUF2 # SAVE A,L AND GET DP RETURN.
018081,000050: 13,2037 52365 DXCH EBUF2 # SAVE DP RETURN.
018082,000051: 13,2040 24364 INCR EBUF2 # RETURN +1 BECAUSE DOUBLE CADR.
018083,000052: 13,2041 30006 CA BBANK
018084,000053: 13,2042 75054 MASK LOW10 # GET CURRENT EBANK. (SBANK SOMEDAY)
018085,000054: 13,2043 26365 ADS EBUF2 +1 # FORM BBCON. (WAS FBANK)
018086,000055: 13,2044 50364 NDX EBUF2
018087,000056: 13,2045 27777 CA 0 -1 # GET CADR OF ROUTINE.
018088,000057: 13,2046 04666 TC SWCALL # GO TO ROUTINE, SETTING Q TO SWRETURN
018089,000058: # AND RESTORING A + L.
018090,000059: 13,2047 02053 TC +4 # TX Q, V34, OR BAD STALL RETURN.
018091,000060: 13,2050 02052 TC +2 # PROCEED OR GOOD STALL RETURN.
018092,000061: 13,2051 24364 INCR EBUF2 # ENTER OR RECYCLE RETURN.
018093,000062: 13,2052 24364 INCR EBUF2
018094,000063: 13,2053 52365 E/SWITCH DXCH EBUF2
018095,000064: 13,2054 52006 DTCB
018096,000065:
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Page 421
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018098,000067: # E/CALL FOR CALLING A FIXED MEMORY INTERPRETIVE SUBROUTINE FROM ERASABLE AND RETURNING TO ERASABLE.
018099,000068:
018100,000069: # THE CALLING SEQUENCE IS...
018101,000070:
018102,000071: # RTB
018103,000072: # E/CALL
018104,000073: # CADR ROUTINE THE INTERPRETIVE SUBROUTINE YOU WANT.
018105,000074: # RETURNS HERE IN INTERPRETIVE.
018106,000075:
018107,000076: 13,2055 22164 E/CALL LXCH LOC # ADRES -1 OF CADR.
018108,000077: 13,2056 50001 INDEX L
018109,000078: 13,2057 30001 CA L # CADR IN A.
018110,000079: 13,2060 24001 INCR L
018111,000080: 13,2061 24001 INCR L # RETURN ADRES IN L.
018112,000081: 13,2062 52365 DXCH EBUF2 # STORE CADR AND RETURN.
018113,000082: 13,2063 06006 TC INTPRET
018114,000083: 13,2064 77624 CALL
018115,000084: 13,2065 00364 EBUF2 # INDIRECTLY EXECUTE ROUTINE. IT MUST
018116,000085: 13,2066 77776 EXIT # LEAVE VIA RVQ OR EQUIVALENT.
018117,000086: 13,2067 22365 LXCH EBUF2 +1 # PICK UP RETURN.
018118,000087: 13,2070 16010 TCF INTPRET +2 # SET LOC AND RETURB TO CALLER
018119,000088:
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Page 422
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018121,000090: # E/JOBWAK FOR WAKING UP ERASABLE MEMORY JOBS.
018122,000091:
018123,000092: # THIS ROUTINE MUST BE CALLED IN INTERRUPT OR WITH INTERRUPTS INHIBITED.
018124,000093:
018125,000094: # THE CALLING SEQUENCE IS:
018126,000095:
018127,000096: # INHINT
018128,000097: # .
018129,000098: # .
018130,000099: # CA WAKEADR ADDRESS OF SLEEPING JOB
018131,000100: # TC IBNKCALL
018132,000101: # CADR E/JOBWAK
018133,000102: # . RETURNS HERE
018134,000103: # .
018135,000104: # .
018136,000105: # RELINT IF YOU DID AN INHINT.
018137,000106:
018138,000107: 33,2000 BANK 33
018139,000108: 04,2000 SETLOC E/PROG
018140,000109: 04,2000 BANK
018141,000110:
018142,000111: 04,2606 COUNT* $$/P07
018143,000112:
018144,000113: 04,2606 05201 E/JOBWAK TC JOBWAKE # ARRIVE IWTH ADRES IN A.
018145,000114: 04,2607 45005 CS BIT11
018146,000115: 04,2610 50064 NDX LOCCTR
018147,000116: 04,2611 26164 ADS LOC # KNOCK FIXED MEMORY BIT OUT OF ADRES.
018148,000117: 04,2612 00072 TC RUPTREG3 # RETURN
018149,000118:
018150,000119:
018151,000120: # THESE PROGRAMS ARE PROVIDED TO ALLOW OVERLAY OF BANKS 30 THRU 33 OF THE 205 VERSIONS OF SYSTEM TESTS AND
018152,000121: # PRELAUNCH ALIGN. THE INTENT IS TO ALLOW THE STG AND HYBRID LABS TO RUN ALL THE TESTS WITH COLOSSUS.
018153,000122:
018154,000123:
018155,000124: 33,2000 BANK 33
018156,000125: 33,2000 SETLOC TESTLEAD
018157,000126: 33,2000 BANK
018158,000127:
018159,000128: 33,2000 COUNT 33/COMST
018160,000129:
018161,000130: 33,2000 E5,1425 EBANK= QPLACE
018162,000131:
018163,000132: 33,2000 03436 COMPVER TC GCOMPVER # MUST BE 33,2000.
018164,000133:
018165,000134: 33,2001 03131 GTSCPSS1 TC GTSCPSS # MUST BE AT 33,2001
018166,000135:
018167,000136: 33,2002 05354 REDO TC NEWMODEX # DISPLAY MM 07.
018168,000137: 33,2003 00007 MM 07 B-14 # FALL INTO IMUTEST
018169,000138:
End of include-file SYSTEM_TEST_STANDARD_LEAD_INS.agc. Parent file is MAIN.agc