Source Code

These source-code files were transcribed from scans made from Don Eyles's personal copy of BURST120 (SUNBURST 120). They were scanned at archive.org's Boston facility, and the scanning was sponsored by Mike Stewart. The code was transcribed from these scans by a team of volunteers who are referenced in the program comments. Comments from the original source code are in ALL-CAPS, whereas comments added later in transcription are in Mixed-Case. In some cases, where similar code blocks exist in previously-transcribed AGC programs (primarily Luminary 99, from Apollo 11) those code blocks were used as a starting point and then corrected to agree with the BURST120 scans. The full scans are available at the Virtual AGC project's collection at archive.org, while more-convenient reduced-size (but reduced-quality) images are available at the main Virtual AGC website. Report any errors noted by creating an issue report at the Virtual AGC project's GitHub repository. Notations on the program listing read, in part:

	YUL SYSTEM FOR AGC: REVISION 0 OF PROGRAM BURST120 
	BY NASA 2021106-031 DEC 7, 1967

	THIS LISTING IS A COPY OF A VERSION OF THE PROGRAM INTENDED 
	FOR USE IN THE ON-BOARD PRIMARY GUIDANCE COMPUTER IN THE 
	UNMANNED FLIGHT OF APOLLO LUNAR MODULE 1 --- THE AS206 MISSION.
Note that the date is the date of the printout, not the date of the program revision.

039036,000002:                                                                                                  ## Copyright:    Public domain.
039037,000003:                                                                                                  ## Filename:     PREBURN_FOR_APS2.agc
039038,000004:                                                                                                  ## Purpose:      A module for revision 0 of BURST120 (Sunburst). It
039039,000005:                                                                                                  ##               is part of the source code for the Lunar Module's
039040,000006:                                                                                                  ##               (LM) Apollo Guidance Computer (AGC) for Apollo 5.
039041,000007:                                                                                                  ## Assembler:    yaYUL
039042,000008:                                                                                                  ## Contact:      Ron Burkey <info@sandroid.org>.
039043,000009:                                                                                                  ## Website:      www.ibiblio.org/apollo/index.html
039044,000010:                                                                                                  ## Mod history:  2016-09-30 RSB  Created draft version.
039045,000011:                                                                                                  ##               2016-10-28 HG   Transcribed
039046,000012:                                                                                                  ##               2016-10-31 RSB  Typos
039047,000013:                                                                                                  ##               2016-12-06 RSB  Comment proofing via octopus/ProoferComments
039048,000014:                                                                                                  ##                               performed, and changes made.
039049,000015: 

Page 911

039051,000017:                                                                                                  #       PREAPS2 IS A PROGRAM WHICH INITIALIZED **ASCENT** FOR THE 2ND APS
039052,000018:                                                                                                  #  BURN. IT USES RN AND VN(TIG), PROVIDED BY MIDTOAVE THROUGH MP13, TO COM-
039053,000019:                                                                                                  #  PUTE THE P, Q, AND S AXES FOR TRANSFORMATIONS, SETS 3 SWITCHES FOR PRO-
039054,000020:                                                                                                  #  PER MODING OF ASCENT, AND TRANSFERS DATA FROM FIXED TO ERASABLE FOR USE
039055,000021:                                                                                                  #  AS NOMINALS AT TIG.
039056,000022:                                                                                                  #       IT CALLS ASCENT ONCE TO PROVIDE UT AT IGNITION, AND THEN RESETS THE
039057,000023:                                                                                                  #  EXIT FROM ASCENT TO GO TO FINDCDUD ON SUBSEQUENT ASCENT ENTRIES.
039058,000024: 
039059,000025: 32,2000                                           BANK     32                                    
039060,000026: 32,2000  E4,1400                                  EBANK=   PAXIS1                                
039061,000027: 32,2000           53447        PREAPS2            DXCH     RRETURN                               
039062,000028: 32,2001           35644                           CA       PRIO21                                #  GIVE LAMBERT A HIGHER PRIORITY THAN
039063,000029: 32,2002           55451                           TS       LAMPRIO                               #  ASCENT, SO IT WILL FINISH.
039064,000030: 32,2003           06112                           TC       INTPRET                               
039065,000031: 32,2004           77624                           CALL                                           
039066,000032: 32,2005           60436                                    VPATCHER                              
039067,000033: 32,2006           77775                           VLOAD                                          
039068,000034: 32,2007           01011                                    RN                                    #  LOAD RN*2(N-29)
039069,000035: 32,2010           53435                           VXV      UNIT                                  #  RN X VN*2(N-36)
039070,000036: 32,2011           01017                                    VN                                    #  SAXIS*2(-1)
039071,000037: 32,2012           02015                           STORE    SAXIS                                 #  STORE SAXIS
039072,000038: 32,2013           76435                           VXV      VSL1                                  #  S X UR*2(-2)=Q1*2(-2), NORM TO S AND R
039073,000039: 32,2014           01033                                    UNITR                                 #  Q1*2(-1)
039074,000040: 32,2015           63361                           VXSC     PDVL                                  #  Q1* COS27*2(-1)
039075,000041: 32,2016           03602                                    COS27                                 #  IN PDL(0)*2(-1)                          2
039076,000042: 32,2017           01033                                    UNITR                                 #  LOAD UR*2(-1)
039077,000043: 32,2020           51361                           VXSC     BVSU                                  #  UR SIN27*2(-1)
039078,000044: 32,2021           03604                                    SIN27                                 #  Q1 COS27-UR SIN27 = Q
039079,000045: 32,2022           77626                           STADR                                          #                                           0
039080,000046: 32,2023           75770                           STORE    QAXIS                                 #  STORE QAXIS
039081,000047: 32,2024           76435                           VXV      VSL1                                  #  Q X S*2(-2) = P*2(-2)
039082,000048: 32,2025           02015                                    SAXIS                                 #  P*2(-1)
039083,000049: 32,2026           26001                           STOVL    PAXIS1                                #  STORE PAXIS
039084,000050: 32,2027           24111                                    ENGNOM                                #  LOAD NOMINAL AT,VE,TBUP
039085,000051: 32,2030           26023                           STOVL    AT                                    #  STORE IN ERASE
039086,000052: 32,2031           24117                                    PREIGN                                #  LOAD NOM, 1/DV1, 1/DV2, 1/DV3.
039087,000053: 32,2032           16031                           STODL    ATMEAS                                #  STORE IN ERASE
039088,000054: 32,2033           26641                                    DP.5                                  
039089,000055: 32,2034           16061                           STODL    KR                                    #  LOAD PITCH LIMITING PARAMETER
039090,000056: 32,2035           26643                                    DP0                                   #  LOAD 0
039091,000057: 32,2036           26037                           STOVL    KR1                                   #  STORE IN KR1
039092,000058: 32,2037           03606                                    VCONOM                                #  LOAD NOM. RDOTD,YDOTD,ZDOTD
039093,000059: 32,2040           16041                           STODL    RDOTD                                 
039094,000060: 32,2041           03576                                    VTO-APS                               
039095,000061: 32,2042           02057                           STORE    VTO                                   
039096,000062: 32,2043           71331                           SSP      DLOAD                                 
039097,000063: 32,2044           02051                                    ASCRET                                
039098,000064: 32,2045           64067                                    PRAPS                                 #  LOAD RETURN ADD. FROM ASCENT
039099,000065: 32,2046           03600                                    TGONOM                                
039100,000066: 32,2047           02141                           STORE    TGO                                   #  TGO$2(-17)
039101,000067: 

Page 912

039103,000069: 32,2050           43261                           SR       DAD                                   
039104,000070: 32,2051           20614                                    11D                                   #  TGO$2(-28)
039105,000071: 32,2052           02377                                    TIGNTION                              
039106,000072: 32,2053           02053                           STORE    TCO                                   #  TCO$2(-28)
039107,000073: 32,2054           43014                           SET      CLEAR                                 
039108,000074: 32,2055           02067                                    DIRECT                                #  DIRECT=1
039109,000075: 32,2056           02266                                    BAKTO4                                #  BAKTO4 = 0
039110,000076: 32,2057           77614                           SET                                            #  TO AVOID CLOBBERING TCO DURING PREBURN
039111,000077: 32,2060           02070                                    PASS                                  
039112,000078: 32,2061           43014                           CLEAR    SET                                   #  CLEAR GUESSW FOR NO COGAVAIL
039113,000079: 32,2062           02263                                    GUESSW                                
039114,000080: 32,2063           02061                                    DONESW                                #  TO START LAMBERT
039115,000081: 32,2064           52014                           CLEAR    GOTO                                  
039116,000082: 32,2065           02271                                    HC                                    #  HC=0
039117,000083: 32,2066           64125                                    ASCENT                                #  GO TO ASCENT EQUATIONS
039118,000084: 32,2067           43175        PRAPS              VLOAD    SET                                   
039119,000085: 32,2070           02233                                    AXISD                                 
039120,000086: 32,2071           02063                                    GUESSW                                #  SET GUESSW FOR COGAVAIL
039121,000087: 32,2072           25656                           STOVL    POINTVSM                              #  STORE FOR CALCMANU
039122,000088: 32,2073           26641                                    BODYVECT                              #  LOAD UNIT X-AXIS
039123,000089: 32,2074           01664                           STORE    SCAXIS                                #  STORE FOR CALCMANU
039124,000090: 32,2075           43014                           SET      CLEAR                                 
039125,000091: 32,2076           02061                                    DONESW                                
039126,000092: 32,2077           02273                                    ENGOFFSW                              
039127,000093: 32,2100           77776                           EXIT                                           
039128,000094: 32,2101           32124                           CA       CDUFAD                                #  SET UP FOR NORMAL EXIT FROM ASCENT TO
039129,000095: 32,2102           55450                           TS       ASCRET                                #  FINDCDUD
039130,000096: 32,2103           35643                           CA       PRIO17                                #  GIVE LAMBERT A LOWER PRIORITY
039131,000097: 32,2104           55451                           TS       LAMPRIO                               
039132,000098: 32,2105           00006                           EXTEND                                         
039133,000099: 32,2106           31447                           DCA      RRETURN                               #  GO BACK TO MP13
039134,000100: 32,2107           52006                           DXCH     Z                                     
039135,000101: 32,2110           05327 16434  ENGNOM             2DEC     .00033086  B9                         #  AT*2(9)
039136,000102: 32,2112           07446 31055                     2DEC     30.3030                               #  VE*2(-7)
039137,000103: 32,2114           26270 16315                     2DEC     91587.6                               #  TBUP*2(-17)
039138,000104: 32,2116           03627 35747  PREIGN             2DEC     15.187                                #  1/DV1
039139,000105: 32,2120           03624 03045                     2DEC     15.157                                #  1/DV2
039140,000106: 32,2122           03620 10142                     2DEC     15.127                                #  1/DV3
039141,000107: 32,2124  33,2640               DP.5               =        BODYVECT                              
039142,000108: 32,2124  33,2642               DP0                =        BODYVECT   +2                         
039143,000109: 32,2124  E4,1400                                  EBANK=   PAXIS1                                
039144,000110: 32,2124           60703        CDUFAD             FCADR    FINDCDUD                              

End of include-file PREBURN_FOR_APS2.agc.  Parent file is MAIN.agc