Source Code

This is a reconstruction of the AGC program Luminary 99 Rev 0. It was the second release of the Lunar Module flight software targeted for use in Apollo 11, after Luminary 97. A bug (which had been around since at least Apollo 10, Luminary 69) was discovered in Rev 0 shortly before the Apollo 11 flight, resulting in a last minute revision into Rev 1, which is what actually flew rather than the Rev 0 presented here. A hardcopy of Rev 0 is known to exist — it belonged to AGC developer Allan Klumpp for many years — but unfortunately the Virtual AGC Project has not had access to that hardcopy. Thus the code you see here had been reconstructed (we believe accurately) rather than transcribed. The first step of the reconstruction of the Rev 0 source code was the transcription of the Rev 1 source code from a hardcopy in the MIT Museum collection. The process of reverting the active portion of the source code (i.e., other than program comments) from Rev 1 to Rev 0 was very minor, consisting only of moving the position of the STARTSB1 label in FRESH START AND RESTART. Allan had previously given us the checksums of the memory banks of Rev 0, and we have verified the program presented here has checksums identical to all banks of Allan's listing of Rev 0. The notations on Allan's Rev 0 program listing read, in part:

	GAP:  ASSEMBLE REVISION 099 OF AGC PROGRAM LUMINARY BY NASA 2021112-051

A single program comment is known to differ between Rev 0 and Rev 1, but these are harder to reconstruct and verify than changes to the active portion of the code. Thus it is possible that there are additional differences between the program comments in Rev 0 and Rev 1 that are unknown to us, and therefore are not reflected in the code presented here.

044322,000002:                                                                                                  ## Copyright:   Public domain.
044323,000003:                                                                                                  ## Filename:    INTER-BANK_COMMUNICATION.agc
044324,000004:                                                                                                  ## Purpose:     Part of the reconstructed source code for LMY99 Rev 0,
044325,000005:                                                                                                  ##              otherwise known as Luminary Rev 99, the second release
044326,000006:                                                                                                  ##              of the Apollo Guidance Computer (AGC) software for Apollo 11.
044327,000007:                                                                                                  ##              It differs from LMY99 Rev 1 (the flown version) only in the
044328,000008:                                                                                                  ##              placement of a single label. The corrections shown here have
044329,000009:                                                                                                  ##              been verified to have the same bank checksums as AGC developer
044330,000010:                                                                                                  ##              Allan Klumpp's copy of Luminary Rev 99, and so are believed
044331,000011:                                                                                                  ##              to be accurate. This file is intended to be a faithful 
044332,000012:                                                                                                  ##              recreation, except that the code format has been changed to 
044333,000013:                                                                                                  ##              conform to the requirements of the yaYUL assembler rather than 
044334,000014:                                                                                                  ##              the original YUL assembler.
044335,000015:                                                                                                  ##
044336,000016:                                                                                                  ## Assembler:   yaYUL
044337,000017:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
044338,000018:                                                                                                  ## Website:     www.ibiblio.org/apollo.
044339,000019:                                                                                                  ## Pages:       998-1001
044340,000020:                                                                                                  ## Mod history: 2009-05-24 RSB  Adapted from the corresponding 
044341,000021:                                                                                                  ##                              Luminary131 file, using page 
044342,000022:                                                                                                  ##                              images from Luminary 1A.
044343,000023:                                                                                                  ##              2011-05-08 JL   Removed workaround.
044344,000024:                                                                                                  ##              2016-12-17 RSB  Proofed text comments with octopus/ProoferComments
044345,000025:                                                                                                  ##                              and corrected the errors found.
044346,000026:                                                                                                  ##              2017-03-13 RSB  Comment-text fixes noted in proofing Luminary 116.
044347,000027:                                                                                                  ##              2017-03-17 RSB  Comment-text fixes identified in diff'ing
044348,000028:                                                                                                  ##                              Luminary 99 vs Comanche 55.
044349,000029:                                                                                                  ##              2017-08-01 MAS  Created from LMY99 Rev 1.
044350,000030: 
044351,000031:                                                                                                  ## This source code has been transcribed or otherwise adapted from
044352,000032:                                                                                                  ## digitized images of a hardcopy from the MIT Museum.  The digitization
044353,000033:                                                                                                  ## was performed by Paul Fjeld, and arranged for by Deborah Douglas of
044354,000034:                                                                                                  ## the Museum.  Many thanks to both.  The images (with suitable reduction
044355,000035:                                                                                                  ## in storage size and consequent reduction in image quality as well) are
044356,000036:                                                                                                  ## available online at www.ibiblio.org/apollo.  If for some reason you
044357,000037:                                                                                                  ## find that the images are illegible, contact me at info@sandroid.org
044358,000038:                                                                                                  ## about getting access to the (much) higher-quality images which Paul
044359,000039:                                                                                                  ## actually created.
044360,000040:                                                                                                  ##
044361,000041:                                                                                                  ## The code has been modified to match LMY99 Revision 0, otherwise
044362,000042:                                                                                                  ## known as Luminary Revision 99, the Apollo 11 software release preceeding
044363,000043:                                                                                                  ## the listing from which it was transcribed. It has been verified to
044364,000044:                                                                                                  ## contain the same bank checksums as AGC developer Allan Klumpp's listing
044365,000045:                                                                                                  ## of Luminary Revision 99 (for which we do not have scans).
044366,000046:                                                                                                  ##
044367,000047:                                                                                                  ## Notations on Allan Klumpp's listing read, in part:
044368,000048:                                                                                                  ##
044369,000049:                                                                                                  ##      ASSEMBLE REVISION 099 OF AGC PROGRAM LUMINARY BY NASA 2021112-51
044370,000050: 

Page 998

044372,000052:                                                                                                  #  THE FOLLOWING ROUTINE CAN BE USED TO CALL A SUBROUTINE IN ANOTHER BANK. IN THE BANKCALL VERSION, THE
044373,000053:                                                                                                  #  CADR OF THE SUBROUTINE IMMEDIATELY FOLLOWS THE TC BANKCALL INSTRUCTION, WITH C(A) AND C(L) PRESERVED.
044374,000054: 
044375,000055:    4616                                           BLOCK    02                                    
044376,000056:    4616                                           COUNT*   $$/BANK                               
044377,000057:    4616           52134        BANKCALL           DXCH     BUF2                                  #  SAVE INCOMING A,L.
044378,000058:    4617           50002                           INDEX    Q                                     #  PICK UP CADR.
044379,000059:    4620           30000                           CA       0                                     
044380,000060:    4621           24002                           INCR     Q                                     #  SO WE RETURN TO THE LOC. AFTER THE CADR.
044381,000061: 
044382,000062:                                                                                                  #  SWCALL IS  IDENTICAL TO BANKCALL, EXCEPT THAT THE CADR ARRIVES IN A.
044383,000063: 
044384,000064:    4622           54001        SWCALL             TS       L                                     
044385,000065:    4623           22004                           LXCH     FBANK                                 #  SWITCH BANKS, SAVING RETURN.
044386,000066:    4624           75012                           MASK     LOW10                                 #  GET SUB-ADDRESS OF CADR.
044387,000067:    4625           56002                           XCH      Q                                     #  A,L NOW CONTAINS DP RETURN.
044388,000068:    4626           52134                           DXCH     BUF2                                  #  RESTORING INPUTS IF THIS IS A BANKCALL.
044389,000069:    4627           50002                           INDEX    Q                                     
044390,000070:    4630           02000                           TC       10000                                 #  SETTING Q TO SWRETURN.
044391,000071: 
044392,000072:    4631           56134        SWRETURN           XCH      BUF2       +1                         #  COMES HERE TO RETURN TO CALLER. C(A,L)
044393,000073:    4632           56004                           XCH      FBANK                                 #  ARE PRESERVED FOR RETURN.
044394,000074:    4633           56134                           XCH      BUF2       +1                         
044395,000075:    4634           00133                           TC       BUF2                                  
044396,000076: 
044397,000077:                                                                                                  #  THE FOLLOWING ROUTINE CAN BE USED AS A UNILATERAL JUMP WITH C(A,L) PRESERVED AND THE CADR IMMEDIATELY
044398,000078:                                                                                                  #  FOLLOWING THE TC POSTJUMP INSTRUCTION.
044399,000079: 
044400,000080:    4635           56002        POSTJUMP           XCH      Q                                     #  SAVE INCOMING C(A).
044401,000081:    4636           50000                           INDEX    A                                     #  GET CADR.
044402,000082:    4637           30000                           CA       0                                     
044403,000083: 
044404,000084:                                                                                                  #  BANKJUMP IS THE SAME AS POSTJUMP, EXCEPT THAT THE CADR ARRIVES IN A.
044405,000085: 
044406,000086:    4640           54004        BANKJUMP           TS       FBANK                                 
044407,000087:    4641           75012                           MASK     LOW10                                 
044408,000088:    4642           56002                           XCH      Q                                     #  RESTORING INPUT C(A) IF THIS WAS A
044409,000089:    4643           50002        Q+10000            INDEX    Q                                     #  POSTJUMP.
044410,000090:    4644           12000        PRIO12             TCF      10000                                 #  PRIO12 = TCF  10000 = 12000
044411,000091: 

Page 999

044413,000093:                                                                                                  #  THE FOLLOWING ROUTINE GETS THE RETURN CADR SAVED BY SWCALL OR BANKCALL AND LEAVES IT IN A.
044414,000094: 
044415,000095:    4645           35012        MAKECADR           CAF      LOW10                                 
044416,000096:    4646           70133                           MASK     BUF2                                  
044417,000097:    4647           60134                           AD       BUF2       +1                         
044418,000098:    4650           00002                           TC       Q                                     
044419,000099: 
044420,000100:    4651           54135        SUPDACAL           TS       MPTEMP                                
044421,000101:    4652           56004                           XCH      FBANK                                 #  SET FBANK FOR DATA.
044422,000102:    4653           00006                           EXTEND                                         
044423,000103:    4654           04007                           ROR      SUPERBNK                              #  SAVE FBANK IN BITS 15-11, AND
044424,000104:    4655           56135                           XCH      MPTEMP                                #  SUPERBANK IN BITS 7-5.
044425,000105:    4656           75012                           MASK     LOW10                                 
044426,000106:    4657           56001                           XCH      L                                     #  SAVE REL. ADR. IN BANK, FETCH SUPERBITS.
044427,000107:    4660           00004                           INHINT                                         #  BECAUSE RUPT DOES NOT SAVE SUPERBANK.
044428,000108:    4661           00006                           EXTEND                                         
044429,000109:    4662           01007                           WRITE    SUPERBNK                              #  SET SUPERBANK FOR DATA.
044430,000110:    4663           50001                           INDEX    L                                     
044431,000111:    4664           32000                           CA       10000                                 #  PINBALL (FIX MEM DISP) PREVENTS DCA HERE
044432,000112:    4665           56135                           XCH      MPTEMP                                #  SAVE 1ST WD, FETCH OLD FBANK AND SBANK.
044433,000113:    4666           00006                           EXTEND                                         
044434,000114:    4667           01007                           WRITE    SUPERBNK                              #  RESTORE SUPERBANK.
044435,000115:    4670           00003                           RELINT                                         
044436,000116:    4671           54004                           TS       FBANK                                 #  RESTORE FBANK.
044437,000117:    4672           30135                           CA       MPTEMP                                #  RECOVER FIRST WORD OF DATA.
044438,000118:    4673           00002                           RETURN                                         #  24 WDS. DATACALL 516 MU, SUPDACAL 432 MU
044439,000119: 

Page 1000

044441,000121:                                                                                                  #  THE FOLLOWING ROUTINES ARE IDENTICAL TO BANKCALL AND SWCALL EXCEPT THAT THEY ARE USED IN INTERRUPT.
044442,000122: 
044443,000123:    4674           52073        IBNKCALL           DXCH     RUPTREG3                              #  USES RUPTREG3,4 FOR DP RETURN ADDRESS.
044444,000124:    4675           50002                           INDEX    Q                                     
044445,000125:    4676           30000                           CAF      0                                     
044446,000126:    4677           24002                           INCR     Q                                     
044447,000127: 
044448,000128:    4700           54001        ISWCALLL           TS       L                                     
044449,000129:    4701           22004                           LXCH     FBANK                                 
044450,000130:    4702           75012                           MASK     LOW10                                 
044451,000131:    4703           56002                           XCH      Q                                     
044452,000132:    4704           52073                           DXCH     RUPTREG3                              
044453,000133:    4705           50002                           INDEX    Q                                     
044454,000134:    4706           02000                           TC       10000                                 
044455,000135: 
044456,000136:    4707           56073        ISWRETRN           XCH      RUPTREG4                              
044457,000137:    4710           56004                           XCH      FBANK                                 
044458,000138:    4711           56073                           XCH      RUPTREG4                              
044459,000139:    4712           00072                           TC       RUPTREG3                              
044460,000140: 
044461,000141:                                                                                                  #  2. USPRCADR ACCESSES INTERPRETIVE CODING IN OTHER THAN THE USER'S FBANK.  THE CALLING SEQUENCE IS AS FOLLOWS:
044462,000142:                                                                                                  #        L       TC      USPRCADR
044463,000143:                                                                                                  #        L+1     CADR    INTPRETX        INTPRETX IS THE INTERPRETIVE CODING
044464,000144:                                                                                                  #                                        RETURN IS TO L+2
044465,000145: 
044466,000146:    4713           54164        USPRCADR           TS       LOC                                   #  SAVE A
044467,000147:    4714           34744                           CA       BIT8                                  
044468,000148:    4715           54023                           TS       EDOP                                  #  EXIT INSTRUCTION TO EDOP
044469,000149:    4716           30006                           CA       BBANK                                 
044470,000150:    4717           54165                           TS       BANKSET                               #  USER'S BBANK TO BANKSET
044471,000151:    4720           50002                           INDEX    Q                                     
044472,000152:    4721           30000                           CA       0                                     
044473,000153:    4722           54004                           TS       FBANK                                 #  INTERPRETIVE BANK TO FBANK
044474,000154:    4723           75012                           MASK     LOW10                                 #  YIELDS INTERPRETIVE RELATIVE ADDRESS
044475,000155:    4724           56002                           XCH      Q                                     #  INTERPRETIVE ADDRESS TO Q, FETCHING L+1
044476,000156:    4725           56164                           XCH      LOC                                   #  L+1 TO LOC, RETRIEVING ORIGINAL A
044477,000157:    4726           14643                           TCF      Q+10000                               
044478,000158: 

Page 1001

044480,000160:                                                                                                  #  THERE ARE FOUR POSSIBLE SETTINGS FOR CHANNEL 07.  (CHANNEL 07 CONTAINS THE SUPERBANK SETTING.)
044481,000161: 
044482,000162:                                                                                                  #                                        PSEUDO-FIXED      OCTAL PSEUDO
044483,000163:                                                                                                  #  SUPERBANK     SETTING S-REG. VALUE    BANK NUMBERS      ADDRESSES
044484,000164:                                                                                                  #  ----------    ------- ------------     ------------      ------------
044485,000165:                                                                                                  #  SUPERBANK 3     0XX    2000 - 3777       30 - 37       70000 - 107777         (WHERE XX CAN BE ANYTHING AND
044486,000166:                                                                                                  #                                                                                WILL USUALLY BE SEEN AS 11)
044487,000167:                                                                                                  #  SUPERBANK 4     100    2000 - 3777       40 - 47      110000 - 127777         (AS FAR AS IT CAN BE SEEN,
044488,000168:                                                                                                  #                                                                                ONLY BANKS 40-43 WILL EVER BE
044489,000169:                                                                                                  #                                                                                AND ARE PRESENTLY AVAILABLE)
044490,000170:                                                                                                  #  SUPERBANK 5     101    2000 - 3777       50 - 57      130000 - 147777         (PRESENTLY NOT AVAILABLE TO
044491,000171:                                                                                                  #                                                                                THE USER)
044492,000172:                                                                                                  #  SUPERBANK 6     110    2000 - 3777       60 - 67      150000 - 167777         (PRESENTLY NOT AVAILABLE TO
044493,000173:                                                                                                  #                                                                                THE USER)
044494,000174:                                                                                                  #  *** THIS ROUTINE MAY BE CALLED BY ANY PROGRAM LOCATED IN BANKS 00 - 27.  I.E., NO PROGRAM LIVING IN ANY
044495,000175:                                                                                                  #  SUPERBANK SHOULD USE SUPERSW. ***
044496,000176: 
044497,000177:                                                                                                  #  SUPERSW MAY BE CALLED IN THIS FASHION:
044498,000178:                                                                                                  #        CAF     ABBCON          WHERE  --  ABBCON   BBCON  SOMETHIN -- 
044499,000179:                                                                                                  #        TCR     SUPERSW         (THE SUPERBNK BITS ARE IN THE BBCON)
044500,000180:                                                                                                  #        ...       ...
044501,000181:                                                                                                  #         .         .
044502,000182:                                                                                                  #         .         .
044503,000183:                                                                                                  #  OR IN THIS FASHION:
044504,000184:                                                                                                  #        CAF     SUPERSET        WHERE SUPERSET IS ONE OF THE FOUR AVAILABLE
044505,000185:                                                                                                  #        TCR     SUPERSW         SUPERBANK BIT CONSTANTS:
044506,000186:                                                                                                  #        ...       ...                                   SUPER011 OCTAL  60
044507,000187:                                                                                                  #         .         .                                    SUPER100 OCTAL 100
044508,000188:                                                                                                  #         .         .                                    SUPER101 OCTAL 120
044509,000189:                                                                                                  #                                                        SUPER110 OCTAL 140
044510,000190: 
044511,000191:    4727           00006        SUPERSW            EXTEND                                         
044512,000192:    4730           01007                           WRITE    SUPERBNK                              #  WRITE BITS 7-6-5 OF THE ACCUMULATOR INTO
044513,000193:                                                                                                  #  CHANNEL 07
044514,000194:    4731           00002                           TC       Q                                     #  TC TO INSTRUCTION FOLLOWING
044515,000195:                                                                                                  #        TC SUPERSW
044516,000196: 

End of include-file INTER-BANK_COMMUNICATION.agc.  Parent file is MAIN.agc