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.

014327,000002:                                                                                                  ## Copyright:   Public domain.
014328,000003:                                                                                                  ## Filename:    R63.agc
014329,000004:                                                                                                  ## Purpose:     Part of the reconstructed source code for LMY99 Rev 0,
014330,000005:                                                                                                  ##              otherwise known as Luminary Rev 99, the second release
014331,000006:                                                                                                  ##              of the Apollo Guidance Computer (AGC) software for Apollo 11.
014332,000007:                                                                                                  ##              It differs from LMY99 Rev 1 (the flown version) only in the
014333,000008:                                                                                                  ##              placement of a single label. The corrections shown here have
014334,000009:                                                                                                  ##              been verified to have the same bank checksums as AGC developer
014335,000010:                                                                                                  ##              Allan Klumpp's copy of Luminary Rev 99, and so are believed
014336,000011:                                                                                                  ##              to be accurate. This file is intended to be a faithful 
014337,000012:                                                                                                  ##              recreation, except that the code format has been changed to 
014338,000013:                                                                                                  ##              conform to the requirements of the yaYUL assembler rather than 
014339,000014:                                                                                                  ##              the original YUL assembler.
014340,000015:                                                                                                  ##
014341,000016:                                                                                                  ## Assembler:   yaYUL
014342,000017:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
014343,000018:                                                                                                  ## Website:     www.ibiblio.org/apollo.
014344,000019:                                                                                                  ## Pages:       338-341
014345,000020:                                                                                                  ## Mod history: 2009-05-16 RSB  Adapted from the corresponding 
014346,000021:                                                                                                  ##                              Luminary131 file, using page 
014347,000022:                                                                                                  ##                              images from Luminary 1A.
014348,000023:                                                                                                  ##              2016-12-14 RSB  Proofed text comments with octopus/ProoferComments
014349,000024:                                                                                                  ##                              and corrected the errors found.
014350,000025:                                                                                                  ##              2017-01-26 RSB  Back-ported a comment-text fix from Luminary 69.
014351,000026:                                                                                                  ##              2017-03-07 RSB  Comment-text fixes noted in proofing Luminary 116.
014352,000027:                                                                                                  ##              2017-08-01 MAS  Created from LMY99 Rev 1.
014353,000028: 
014354,000029:                                                                                                  ## This source code has been transcribed or otherwise adapted from
014355,000030:                                                                                                  ## digitized images of a hardcopy from the MIT Museum.  The digitization
014356,000031:                                                                                                  ## was performed by Paul Fjeld, and arranged for by Deborah Douglas of
014357,000032:                                                                                                  ## the Museum.  Many thanks to both.  The images (with suitable reduction
014358,000033:                                                                                                  ## in storage size and consequent reduction in image quality as well) are
014359,000034:                                                                                                  ## available online at www.ibiblio.org/apollo.  If for some reason you
014360,000035:                                                                                                  ## find that the images are illegible, contact me at info@sandroid.org
014361,000036:                                                                                                  ## about getting access to the (much) higher-quality images which Paul
014362,000037:                                                                                                  ## actually created.
014363,000038:                                                                                                  ##
014364,000039:                                                                                                  ## The code has been modified to match LMY99 Revision 0, otherwise
014365,000040:                                                                                                  ## known as Luminary Revision 99, the Apollo 11 software release preceeding
014366,000041:                                                                                                  ## the listing from which it was transcribed. It has been verified to
014367,000042:                                                                                                  ## contain the same bank checksums as AGC developer Allan Klumpp's listing
014368,000043:                                                                                                  ## of Luminary Revision 99 (for which we do not have scans).
014369,000044:                                                                                                  ##
014370,000045:                                                                                                  ## Notations on Allan Klumpp's listing read, in part:
014371,000046:                                                                                                  ##
014372,000047:                                                                                                  ##      ASSEMBLE REVISION 099 OF AGC PROGRAM LUMINARY BY NASA 2021112-51
014373,000048: 

Page 338

014375,000050:                                                                                                  #  SUBROUTINE NAME:      V89CALL
014376,000051:                                                                                                  #  MOD NO:       0                       DATE:           9 JAN 1968
014377,000052:                                                                                                  #  MOD BY:       DIGITAL DEVEL GROUP     LOG SECTION:    R63
014378,000053: 
014379,000054:                                                                                                  #  FUNCTIONAL DESCRIPTION:
014380,000055: 
014381,000056:                                                                                                  #  CALLED BY VERB 89 ENTER DURING P00.  PRIO 10 USED.  CALCULATES AND
014382,000057:                                                                                                  #  DISPLAYS FINAL FDAI BALL ANGLES TO POINT LM +X OR +Z AXIS AT CSM.
014383,000058: 
014384,000059:                                                                                                  #  1. KEY IN V 89 E ONLY IF IN PROG 00.  IF NOT IN P00, OPERATOR ERROR AND
014385,000060:                                                                                                  #  EXIT R63, OTHERWISE CONTINUE.
014386,000061: 
014387,000062:                                                                                                  #  2. IF IN P00, DO IMU STATUS CHECK ROUTINE (R02BOTH).  IF IMU ON AND ITS
014388,000063:                                                                                                  #  ORIENTATION KNOWN TO LGC, CONTINUE.
014389,000064: 
014390,000065:                                                                                                  #  3. FLASH DISPLAY V 04 N 06.  R2 INDICATES WHICH SPACECRAFT AXIS IS TO
014391,000066:                                                                                                  #  BE POINTED AT CSM.  INITIAL CHOICE IS PREFERRED (+Z) AXIS (R2=1).
014392,000067:                                                                                                  #  ASTRONAUT CAN CHANGE TO (+X) AXIS (R2 NOT =1) BY V 22 E 2 E.  CONTINUE
014393,000068:                                                                                                  #  AFTER KEYING IN PROCEED.
014394,000069: 
014395,000070:                                                                                                  #  4. BOTH VEHICLE STATE VECTORS UPDATED BY CONIC EQS.
014396,000071: 
014397,000072:                                                                                                  #  5. HALF MAGNITUDE UNIT LOS VECTOR (IN STABLE MEMBER COORDINATES) AND
014398,000073:                                                                                                  #  HALF MAGNITUDE UNIT SPACECRAFT AXIS VECTOR (IN BODY COORDINATES)
014399,000074:                                                                                                  #  PREPARED FOR VECPOINT.
014400,000075: 
014401,000076:                                                                                                  #  6. GIMBAL ANGLES FROM VECPOINT TRANSFORMED INTO FDAI BALL ANGLES BY
014402,000077:                                                                                                  #  BALLANGS.  FLASH DISPLAY V 06 N 18 AND AWAIT RESPONSE.
014403,000078: 
014404,000079:                                                                                                  #  7.    RECYCLE - RETURN TO STEP 4.
014405,000080:                                                                                                  #        TERMINATE - EXIT R63.
014406,000081:                                                                                                  #        PROCEED - RESET 3AXISFLG AND CALL R60LEM FOR ATTITUDE MANEUVER.
014407,000082: 
014408,000083:                                                                                                  #  CALLING SEQUENCE:     V 89 E.
014409,000084: 
014410,000085:                                                                                                  #  SUBROUTINES CALLED:   CHKPOOH, R02BOTH, GOXDSPF, CSMCONIC, LEMCONIC,
014411,000086:                                                                                                  #                        VECPOINT, BALLANGS, R60LEM.
014412,000087: 
014413,000088:                                                                                                  #  NORMAL EXIT MODES:    TC ENDEXT
014414,000089: 
014415,000090:                                                                                                  #  ALARMS:       1. OPERATOR ERROR IF NOT IN P00.
014416,000091:                                                                                                  #                2. PROGRAM ALARM IF IMU IS OFF.
014417,000092:                                                                                                  #                3. PROGRAM ALARM IF IMU ORIENTATION IS UNKNOWN.
014418,000093: 
014419,000094:                                                                                                  #  OUTPUT:       NONE
014420,000095: 
014421,000096:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:  NONE
014422,000097: 
014423,000098:                                                                                                  #  DEBRIS:       OPTION1, +1, TDEC1, POINTVSM, SCAXIS, CPHI, CTHETA, CPSI,

Page 339

014425,000100:                                                                                                  #                3AXISFLG.
014426,000101: 
014427,000102: 06,3715  E4,1606                                  EBANK=   RONE                                  
014428,000103: 32,2217                                           BANK     32                                    
014429,000104: 26,2000                                           SETLOC   BAWLANGS                              
014430,000105: 26,2000                                           BANK                                           
014431,000106: 
014432,000107: 26,2022                                           COUNT*   $$/R63                                
014433,000108: 26,2022           04616        V89CALL            TC       BANKCALL                              #  IMU STATUS CHECK.  RETURNS IF ORIENTATION
014434,000109: 26,2023           11254                           CADR     R02BOTH                               #  KNOWN.  ALARMS IF NOT.
014435,000110: 26,2024           36245                           CAF      THREE                                 #  ALLOW ASTRONAUT TO SELECT DESIRED
014436,000111: 26,2025           55051                           TS       OPTIONX                               #  TRACKING ATTITUDE AXIS.
014437,000112: 26,2026           34753                           CAF      ONE                                   
014438,000113: 26,2027           55052                           TS       OPTIONX    +1                         
014439,000114: 26,2030           32117                           CAF      VB04N12                               #  V 04 N 12
014440,000115: 26,2031           04616                           TC       BANKCALL                              
014441,000116: 26,2032           20476                           CADR     GOFLASH                               
014442,000117: 26,2033           05472                           TC       ENDEXT                                #  TERMINATE
014443,000118: 26,2034           02036                           TC       +2                                    #  PROCEED
014444,000119: 26,2035           02030                           TC       -5                                    #  DATA IN. OPTION1+1 = 1 FOR Z AXIS
014445,000120: 26,2036           06037        V89RECL            TC       INTPRET                               #                    = 2 FOR X AXIS
014446,000121: 26,2037           43234                           RTB      DAD                                   
014447,000122: 26,2040           21573                                    LOADTIME                              #  READ PRESENT TIME
014448,000123: 26,2041           14122                                    DP1MIN                                
014449,000124: 26,2042           02205                           STORE    TSTART82                              #  SAVE TIME FOR LEMCONIC CALL
014450,000125: 26,2043           34041                           STCALL   TDEC1                                 #  STORE TIME FOR CSMCONIC CALL
014451,000126: 26,2044           27066                                    CSMCONIC                              #  CSM STATE VECTOR UPDATE
014452,000127: 26,2045           77775                           VLOAD                                          #  CSMCONIC LEFT R VECTOR IN RATT
014453,000128: 26,2046           00001                                    RATT                                  
014454,000129: 26,2047           16207                           STODL    RONE                                  #  SAVE FOR LINE OF SIGHT (LOS) COMPUTATION
014455,000130: 26,2050           02205                                    TSTART82                              
014456,000131: 26,2051           34041                           STCALL   TDEC1                                 #  STORE TIME FOR LEMCONIC CALL
014457,000132: 26,2052           27100                                    LEMCONIC                              #  LEM STATE VECTOR UPDATE
014458,000133: 26,2053           52375                           VLOAD    VSU                                   #  CSM POSITION - LEM POSITION = LOS
014459,000134: 26,2054           02207                                    RONE                                  #  LOS VECTOR LEFT IN MPAC
014460,000135: 26,2055           00001                                    RATT                                  
014461,000136: 26,2056           47121                           MXV      RTB                                   #  (REFSMMAT X LOS).  TRANSFORMS LOS FROM
014462,000137: 26,2057           01734                                    REFSMMAT                              #  REFERENCE COORD TO STAB MEMB COORD.
014463,000138: 26,2060           21726                                    NORMUNIT                              
014464,000139: 26,2061           03773                           STORE    POINTVSM                              #  STORE LOS FOR VECPOINT CALL
014465,000140: 26,2062           77776                           EXIT                                           
014466,000141: 26,2063           41052                           CS       OPTIONX    +1                         #  1 FOR Z AXIS.  2 FOR X AXIS.
014467,000142: 26,2064           64753                           AD       ONE                                   
014468,000143: 26,2065           00006                           EXTEND                                         
014469,000144: 26,2066           12113                           BZF      ALINEZ                                
014470,000145: 26,2067           06037        ALINEX             TC       INTPRET                               #  X AXIS ALIGNMENT
014471,000146: 26,2070           77775                           VLOAD                                          
014472,000147: 26,2071           06520                                    UNITX                                 #  READ (.5, 0, 0)

Page 340

014474,000149: 26,2072           37765        V89CALL1           STCALL   SCAXIS                                #  STORE SELECTED ALIGNMENT AXIS
014475,000150: 26,2073           56040                                    VECPOINT                              #  PUTS DESIRED GIM ANG (OG,IG,MG) IN TMPAC
014476,000151: 26,2074           00322                           STORE    CPHI                                  #  STORE GIMBAL ANGLES FOR BALLANGS CALL.
014477,000152: 26,2075           77776                           EXIT                                           
014478,000153: 26,2076           04616                           TC       BANKCALL                              
014479,000154: 26,2077           54266                           CADR     BALLANGS                              #  PUTS DESIRED BALL ANGLES IN FDAIX,Y,Z
014480,000155: 26,2100           32120                           CAF      VB06N18                               #  V 06 N 18
014481,000156: 26,2101           04616                           TC       BANKCALL                              #  NOUN 18 REFERS TO FDAIX,Y,Z
014482,000157: 26,2102           20476                           CADR     GOFLASH                               
014483,000158: 26,2103           05472                           TC       ENDEXT                                #  TERMINATE
014484,000159: 26,2104           02106                           TC       +2                                    #  PROCEED
014485,000160: 26,2105           02036                           TC       V89RECL                               #  RECYCLE
014486,000161: 26,2106           05516                           TC       DOWNFLAG                              #  RESET 3 AXIS FLAG
014487,000162: 26,2107           00124                           ADRES    3AXISFLG                              #  RESET BIT6 FLAG WORD 5
014488,000163: 26,2110           04616                           TC       BANKCALL                              #  PERFORMS LEM MANEUVER TO ALIGN SELECTED
014489,000164: 26,2111           54123                           CADR     R60LEM                                #  SPACECRAFT AXIS TO CSM.
014490,000165: 26,2112           15472                           TCF      ENDEXT                                #  TERMINATE R63
014491,000166: 
014492,000167: 26,2113           06037        ALINEZ             TC       INTPRET                               #  Z AXIS ALIGNMENT
014493,000168: 26,2114           52175                           VLOAD    GOTO                                  
014494,000169: 26,2115           06514                                    UNITZ                                 #  READ (0, 0, .5)
014495,000170: 26,2116           54072                                    V89CALL1                              
014496,000171: 
014497,000172: 26,2117           01014        VB04N12            VN       412                                   
014498,000173: 26,2120           01422        VB06N18            VN       0618                                  

Page 341

014500,000175: 26,2121           00000 13560  DP1MIN             2DEC     6000       B-28                       
014501,000176: 

End of include-file R63.agc.  Parent file is MAIN.agc