Assembly listing generated by yaYUL

Source Code

These source code files are a reconstruction of Sundance, the Apollo 9 LM (Lunar Module) AGC (Apollo Guidance Computer) flight software, created from binary dumps of original core rope program modules, as follows:

B1 — Revision 292
B2 — Revision 302
B3 — Revision 302
B4 — Revision 302
B5 — Revision 292
B6 — Revision 306

This means that source code does not represent a specific historical revision of Sundance, but rather a mixture of the three released versions. Nonetheless, it is capable of flying the whole Apollo 9 mission. This source code matches the binary dumps, as closely as feasible, but 100% match is not possible, due mostly to changes in memory addresses at which code and variables were allocated in different revisions of Sundance. Refer to this list of explanations for each binary mismatch.

Since only binary dumps (rather than listings) of Sundance are available as source material, all comments and labels are approximate. They have been taken from other AGC programs where possible, or, in some places, written from scratch to match what we believe would have been in the original listing.

042500,000002: 042501,000003: 042502,000004: 042503,000005: 042504,000006: 042505,000007: 042506,000008: 042507,000009: 042508,000010: 042509,000011: 042510,000012: 042511,000013: 042512,000014: 042513,000015: 042514,000016: 042515,000017: 5142 042516,000018: 042517,000019: 042518,000020: 5142 < 042520,000022: 5143 042521,000023: 5144 042522,000024: 042523,000025: 5145 042524,000026: 5146 042525,000027: 5147 042526,000028: 5150 042527,000029: 5151 042528,000030: 5152 042529,000031: 5153 042530,000032: 5154 042531,000033: 042532,000034: 042533,000035: < 042549,000051: 5167 042550,000052: 5170 042551,000053: 5171 042552,000054: 042553,000055: 042554,000056: 042908,000410: 042909,000411: 01,3003 042910,000412: 01,3004 042911,000413: 01,3005 042912,000414: 01,3006 042913,000415: 01,3007 042914,000416: 01,3010 042915,000417: 01,3011 042916,000418: 042917,000419: 042918,000420: 01,3013 042919,000421: 01,3014 042920,000422: 01,3015 042921,000423: 01,3016 042922,000424: 042923,000425: 042924,000426: 042925,000427: 042926,000428: 01,3017 042927,000429: < 042935,000437: 01,3026 042936,000438: 01,3027 042937,000439: 01,3030 042938,000440: 042939,000441: 01,3031 042940,000442: 01,3032 042941,000443: 01,3033 042942,000444: 01,3034 042943,000445: 042944,000446: 01,3035 ## Copyright: Public domain. ## Filename: EXECUTIVE.agc ## Purpose: A section of a reconstructed, mixed version of Sundance ## It is part of the reconstructed source code for the Lunar ## Module's (LM) Apollo Guidance Computer (AGC) for Apollo 9. ## No original listings of this program are available; ## instead, this file was created via disassembly of dumps ## of various revisions of Sundance core rope modules. ## Assembler: yaYUL ## Contact: Ron Burkey <info@sandroid.org>. ## Website: www.ibiblio.org/apollo/index.html ## Mod history: 2020-06-17 MAS Created from Luminary 69. ## Sundance 292 BLOCK 02 # TO ENTER A JOB REQUEST REQUIRING NO VAC AREA: COUNT* $$/EXEC /a>042519,000021: 5142 00004 NOVAC INHINT 65234 AD FAKEPRET # LOC(MPAC +6) - LOC(QPRET) 54063 TS NEWPRIO # PRIORITY OF NEW JOB + NOVAC C(FIXLOC) 00006 EXTEND 50002 INDEX Q # Q WILL BE UNDISTURBED THROUGHOUT. 30001 DCA 0 # 2CADR OF JOB ENTERED. 52066 DXCH NEWLOC 35233 CAF EXECBANK 56004 XCH FBANK 54061 TS EXECTEM1 12444 TCF NOVAC2 # ENTER EXECUTIVE BANK. # TO ENTER A JOB REQUEST REQUIRING A VAC AREA - E.G., ALL (PARTIALLY) INTERPRETIVE JOBS. 3">042534,000036: 5155 00004 FINDVAC INHINT 54063 TS NEWPRIO 00006 EXTEND 50002 INDEX Q 30001 DCA 0 E">042539,000041: 5162 52066 SPVACIN DXCH NEWLOC 35233 CAF EXECBANK 56004 XCH FBANK 12422 TCF FINDVAC2 # OFF TO EXECUTIVE SWITCHED-BANK. # TO ENTER A FINDVAC WITH THE PRIORITY IN NEWPRIO TO THE 2CADR ARRIVING IN A AND L: # USERS OF SPVAC MUST INHINT BEFORE STORING IN NEWPRIO. /a>042548,000050: 5166 56002 SPVAC XCH Q 67720 AD NEG2 56002 XCH Q 15162 TCF SPVACIN # TO SUSPEND A BASIC JOB SO A HIGHER PRIORITY JOB MAY BE SERVICED: >042555,000057: 5172 22002 CHANG1 LXCH Q 35233 CAF EXECBANK 56006 XCH BBANK 12523 TCF CHANJOB # TO SUSPEND AN INTERPRETIVE JOB: >042562,000064: 5176 40164 CHANG2 CS LOC # NEGATIVE LOC SHOWS JOB = INTERPRETIVE. # ITRACE (4) REFERS TO "CHANG2". 54001 TS L 35233 +2 CAF EXECBANK 54006 TS BBANK 12522 TCF CHANJOB -1 # TO VOLUNTARILY SUSPEND A JOB UNTIL THE COMPLETION OF SOME ANTICIPATED EVENT (I/O EVENT ETC.): 550">042572,000074: 5203 54164 JOBSLEEP TS LOC 35233 CAF EXECBANK 54004 TS FBANK 12613 TCF JOBSLP1 # TO AWAKEN A JOB PUT TO SLEEP IN THE ABOVE FASHION: 5">042579,000081: 5207 00004 JOBWAKE INHINT 54065 TS NEWLOC 45025 CS TWO # EXIT IS VIA FINDVAC/NOVAC PROCEDURES. 26002 ADS Q 35233 CAF EXECBANK 56004 XCH FBANK 12640 TCF JOBWAKE2 # TO CHANGE THE PRIORITY OF A JOB CURRENTLY UNDER EXECUTION: E47">042589,000091: 5216 00004 PRIOCHNG INHINT # NEW PRIORITY ARRIVES IN A. RETURNS TO 54063 TS NEWPRIO # CALLER AS SOON AS NEW JOB PRIORITY IS 35233 CAF EXECBANK # HIGHEST. PREPARE FOR POSSIBLE BASIC- 56006 XCH BBANK # STYLE CHANGE-JOB. 54165 TS BANKSET 30002 CA Q 12707 TCF PRIOCH2 # TO REMOVE A JOB FROM EXECUTIVE CONSIDERATIONS: F42">042599,000101: 5225 35233 ENDOFJOB CAF EXECBANK 54004 TS FBANK 12720 TCF ENDJOB1 4">042603,000105: 5230 30061 ENDFIND CA EXECTEM1 # RETURN TO CALLER AFTER JOB ENTRY 54004 TS FBANK # COMPLETE. 16715 TCF Q+2 E4B">042606,000108: 5233 02422 EXECBANK CADR FINDVAC2 554">042608,000110: 5234 00110 FAKEPRET ADRES MPAC -36D # LOC(MPAC +6) - LOC(QPRET) # LOCATE AN AVAILABLE VAC AREA. BANK 01 COUNT* $$/EXEC 332">042614,000116: 01,2422 54061 FINDVAC2 TS EXECTEM1 # (SAVE CALLER'S BANK FIRST.) 10400 CCS VAC1USE 12437 TCF VACFOUND 10454 CCS VAC2USE 12437 TCF VACFOUND 10530 CCS VAC3USE 12437 TCF VACFOUND 10604 CCS VAC4USE 12437 TCF VACFOUND 10660 CCS VAC5USE 12437 TCF VACFOUND 05713 TC ABORT 01201 OCT 1201 # NO VAC AREAS. E44">042628,000130: 01,2437 65025 VACFOUND AD TWO # RESERVE THIS VAC AREA BY STORING A ZERO 22007 ZL # IN ITS VAC USE REGISTER AND STORE THE 50000 INDEX A # ADDRESS OF THE FIRST WORD OF IT IN THE 21777 LXCH 0 -1 # LOW NINE BITS OF THE PRIORITY WORD. 26063 ADS NEWPRIO >042634,000136: 01,2444 35030 NOVAC2 CAF ZERO # NOVAC ENTERS HERE. FIND A CORE SET. 54064 TS LOCCTR 32453 CAF NO.CORES # SEVEN SETS OF ELEVEN REGISTERS EACH. >042637,000139: 01,2447 54062 NOVAC3 TS EXECTEM2 50064 INDEX LOCCTR 10167 CCS PRIORITY # EACH PRIORITY REGISTER CONTAINS -0 IF 12513 TCF NEXTCORE # THE CORRESPONDING CORE SET IS AVAILABLE. 553">042641,000143: 01,2453 00006 NO.CORES DEC 6 B-14 12513 TCF NEXTCORE # AN ACTIVE JOB HAS A POSITIVE PRIORITY # BUT A DORMANT JOB'S PRIORITY IS NEGATIVE E44">042645,000147: 01,2455 30063 CORFOUND CA NEWPRIO # SET THE PRIORITY OF THIS JOB IN THE CORE 50064 INDEX LOCCTR # SET'S PRIORITY REGISTER AND SET THE 54167 TS PRIORITY # JOB'S PUSH-DOWN POINTER AT THE BEGINNING 75054 MASK LOW9 # OF THE WORK AREA AND OVERFLOW INDICATOR 50064 INDEX LOCCTR 54166 TS PUSHLOC # OFF TO PREPARE FOR INTERPRETIVE PROGRAMS 10064 CCS LOCCTR # IF CORE SET ZERO IS BEING LOADED, SET UP 12500 TCF SETLOC # OVFIND AND FIXLOC IMMEDIATELY. 54121 TS OVFIND 30166 CA PUSHLOC 54120 TS FIXLOC 354">042658,000160: 01,2470 10067 SPECTEST CCS NEWJOB # SEE IF ANY ACTIVE JOBS WAITING (RARE). 12500 TCF SETLOC # MUST BE AWAKENED BUT UNCHANGED JOB. 05723 TC CCSHOLE 05723 TC CCSHOLE 54067 TS NEWJOB # +0 SHOWS ACTIVE JOB ALREADY SET. 52066 DXCH NEWLOC 52165 DXCH LOC 15230 TCF ENDFIND >042667,000169: 01,2500 52066 SETLOC DXCH NEWLOC # SET UP THE LOCATION REGISTERS FOR THIS 50064 INDEX LOCCTR 52165 DXCH LOC 50067 INDEX NEWJOB # THIS INDEX INSTRUCTION INSURES THAT THE 40167 CS PRIORITY # HIGHEST ACTIVE PRIORITY WILL BE COMPARED 60063 AD NEWPRIO # WITH THE NEW PRIORITY TO SEE IF NEWJOB 00006 EXTEND # SHOULD BE SET TO SIGNAL A SWITCH. 65230 BZMF ENDFIND 30064 CA LOCCTR # LOCCTR IS LEFT SET AT THIS CORE SET IF 54067 TS NEWJOB # THE CALLER WANTS TO LOAD ANY MPAC 15230 TCF ENDFIND # REGISTERS, ETC. 245">042679,000181: 01,2513 32650 NEXTCORE CAF COREINC 26064 ADS LOCCTR 10062 CCS EXECTEM2 12447 TCF NOVAC3 05713 TC ABORT # NO CORE SETS. 01202 OCT 1202 # THE FOLLOWING ROUTINE SWAPS CORE SET 0 WITH THAT WHOSE RELATIVE ADDRESS IS IN NEWJOB. 22164 -2 LXCH LOC 30165 -1 CAE BANKSET # BANKSET, NOT BBANK, HAS RIGHT CONTENTS. 2">042690,000192: 01,2523 00004 CHANJOB INHINT 00006 EXTEND 04007 ROR SUPERBNK # PICK UP CURRENT SBANK FOR BBCON 56001 XCH L # LOC IN A AND BBCON IN L. 50067 +4 INDEX NEWJOB # SWAP LOC AND BANKSET. 52165 DXCH LOC 52165 DXCH LOC 30165 CAE BANKSET 00006 EXTEND 01007 WRITE SUPERBNK # SET SBANK FOR NEW JOB. 52155 DXCH MPAC # SWAP MULTI-PURPOSE ACCUMULATOR AREAS. 50067 INDEX NEWJOB 52155 DXCH MPAC 52155 DXCH MPAC 52157 DXCH MPAC +2 50067 INDEX NEWJOB 52157 DXCH MPAC +2 52157 DXCH MPAC +2 52161 DXCH MPAC +4 50067 INDEX NEWJOB 52161 DXCH MPAC +4 52161 DXCH MPAC +4 52163 DXCH MPAC +6 50067 INDEX NEWJOB 52163 DXCH MPAC +6 52163 DXCH MPAC +6 35030 CAF ZERO 56121 XCH OVFIND # MAKE PUSHLOC NEGATIVE IF OVFIND NZ. 00006 EXTEND 12563 BZF +3 40166 CS PUSHLOC 54166 TS PUSHLOC 52167 DXCH PUSHLOC 50067 INDEX NEWJOB 52167 DXCH PUSHLOC 52167 DXCH PUSHLOC # SWAPS PUSHLOC AND PRIORITY. 35054 CAF LOW9 # SET FIXLOC TO BASE OF VAC AREA. 70167 MASK PRIORITY 54120 TS FIXLOC 10166 CCS PUSHLOC # SET OVERFLOW INDICATOR ACCORDING TO 35030 CAF ZERO 12601 TCF ENDPRCHG -1 40166 CS PUSHLOC 54166 TS PUSHLOC 35026 CAF ONE 56121 XCH OVFIND 54067 TS NEWJOB 847">042743,000245: 01,2602 00003 ENDPRCHG RELINT 52165 DXCH LOC # BASIC JOBS HAVE POSITIVE ADDRESSES, SO 00006 EXTEND # DISPATCH WITH A DTCB. 62607 BZMF +2 # IF INTERPRETIVE, SET UP EBANK, ETC. 52006 DTCB 40000 COM # EPILOGUE TO JOB CHANGE FOR INTERPRETIVE 65026 AD ONE 54164 TS LOC # RESUME. 16024 TCF INTRSM # COMPLETE JOBSLEEP PREPARATIONS. 1">042756,000258: 01,2613 00004 JOBSLP1 INHINT 40167 CS PRIORITY # NNZ PRIORITY SHOWS JOB ASLEEP. 54167 TS PRIORITY 36050 CAF LOW7 70006 MASK BBANK 00006 EXTEND 04007 ROR SUPERBNK # SAVE OLD SUPERBANK VALUE. 54165 TS BANKSET 45030 CS ZERO 2">042765,000267: 01,2624 54131 JOBSLP2 TS BUF +1 # HOLDS - HIGHEST PRIORITY. 12735 TCF EJSCAN # SCAN FOR HIGHEST PRIORITY ALA ENDOFJOB. 732">042768,000270: 01,2626 00004 NUCHANG2 INHINT # QUICK... DONT LET NEWJOB CHANGE TO +0. 10067 CCS NEWJOB 12633 TCF +3 # NEWJOB STILL PNZ 00003 RELINT # NEW JOB HAS CHANGED TO +0. WAKE UP JOB 13027 TCF ADVAN +2 # VIA NUDIRECT. (VERY RARE CASE.) 35025 CAF TWO 00006 EXTEND 05011 WOR DSALMOUT # TURN ON ACTIVITY LIGHT 52165 DXCH LOC # AND SAVE ADDRESS INFO FOR BENEFIT OF 12527 TCF CHANJOB +4 # POSSIBLE SLEEPING JOB. # TO WAKE UP A JOB, EACH CORE SET IS FOUND TO LOCATE ALL JOBS WHICH ARE ASLEEP. IF THE FCADR IN THE # LOC REGISTER OF ANY SUCH JOB MATCHES THAT SUPPLIED BY THE CALLER, THAT JOB IS AWAKENED. IF NO JOB IS FOUND, # LOCCTR IS SET TO -1 AND NO FURTHER ACTION TAKES PLACE. 532">042784,000286: 01,2640 54061 JOBWAKE2 TS EXECTEM1 35030 CAF ZERO # BEGIN CORE SET SCAN. 54064 TS LOCCTR 32453 CAF NO.CORES 534">042788,000290: 01,2644 54062 JOBWAKE4 TS EXECTEM2 50064 INDEX LOCCTR 10167 CCS PRIORITY 12652 TCF JOBWAKE3 # ACTIVE JOB - CHECK NEXT CORE SET. 3">042792,000294: 01,2650 00014 COREINC DEC 12 B-14 # 12 REGISTERS PER CORE SET. 12661 TCF WAKETEST # SLEEPING JOB - SEE IF CADR MATCHES. 533">042795,000297: 01,2652 32650 JOBWAKE3 CAF COREINC 26064 ADS LOCCTR 10062 CCS EXECTEM2 12644 TCF JOBWAKE4 45026 CS ONE # EXIT IF SLEEPING JOB NOT FOUND. 54064 TS LOCCTR 15230 TCF ENDFIND 354">042803,000305: 01,2661 40065 WAKETEST CS NEWLOC 50064 INDEX LOCCTR 60164 AD LOC 00006 EXTEND 12667 BZF +2 # IF MATCH. 12652 TCF JOBWAKE3 # EXAMINE NEXT CORE SET IF NO MATCH. 50064 INDEX LOCCTR # RE-COMPLEMENT PRIORITY TO SHOW JOB AWAKE 40167 CS PRIORITY 54063 TS NEWPRIO 50064 INDEX LOCCTR 54167 TS PRIORITY 44362 CS FBANKMSK # MAKE UP THE 2CADR OF THE WAKE ADDRESS 70065 MASK NEWLOC # USING THE CADR IN NEWLOC AND THE EBANK 65014 AD 2K # HALF OF BBANK SAVED IN BANKSET. 56065 XCH NEWLOC 74362 MASK FBANKMSK 50064 INDEX LOCCTR 60165 AD BANKSET 54066 TS NEWLOC +1 10064 CCS LOCCTR # SPECIAL TREATMENT IF THIS JOB WAS 12500 TCF SETLOC # ALREADY IN THE RUN (0) POSITION. 12470 TCF SPECTEST # PRIORITY CHANGE. CHANGE THE CONTENTS OF PRIORITY AND SCAN FOR THE JOB OF HIGHEST PRIORITY. 2">042831,000333: 01,2707 54164 PRIOCH2 TS LOC 35030 CAF ZERO # SET FLAG TO TELL ENDJOB SCANNER IF THIS 54130 TS BUF # JOB IS STILL HIGHEST PRIORITY. 35054 CAF LOW9 70167 MASK PRIORITY 60063 AD NEWPRIO 54167 TS PRIORITY 40000 COM 12624 TCF JOBSLP2 # AND TO EJSCAN. # RELEASE THIS CORE SET AND VAC AREA AND SCAN FOR THE JOB OF HIGHEST ACTIVE PRIORITY. 1">042843,000345: 01,2720 00004 ENDJOB1 INHINT 45030 CS ZERO 54131 TS BUF +1 56167 XCH PRIORITY 75054 MASK LOW9 54001 TS L 45234 CS FAKEPRET 60001 AD L 00006 EXTEND 62735 BZMF EJSCAN # NOVAC ENDOFJOB 10001 CCS L 50000 INDEX A 54000 TS 0 >042860,000362: 01,2735 10203 EJSCAN CCS PRIORITY +12D 03002 TC EJ1 05723 TC CCSHOLE 12741 TCF +1 10217 CCS PRIORITY +24D # EXAMINE EACH PRIORITY REGISTER TO FIND 03002 TC EJ1 # THE JOB OF HIGHEST ACTIVE PRIORITY. 05723 TC CCSHOLE 12745 TCF +1 10233 CCS PRIORITY +36D 03002 TC EJ1 >042872,000374: 01,2747 67610 -CCSPR -CCS PRIORITY 12751 TCF +1 10247 CCS PRIORITY +48D 03002 TC EJ1 05723 TC CCSHOLE 12755 TCF +1 10263 CCS PRIORITY +60D 03002 TC EJ1 05723 TC CCSHOLE 12761 TCF +1 10277 CCS PRIORITY +72D 03002 TC EJ1 05723 TC CCSHOLE 12765 TCF +1 # EVALUATE THE RESULTS OF THE SCAN. 10131 CCS BUF +1 # SEE IF THERE ARE ANY ACTIVE JOBS WAITING 05723 TC CCSHOLE 05723 TC CCSHOLE 12772 TCF +2 13017 TCF DUMMYJOB 10130 CCS BUF # BUF IS ZERO IF THIS IS A PRIOCHNG AND 12775 TCF +2 # CHANGED PRIORITY IS STILL HIGHEST. 12601 TCF ENDPRCHG -1 50000 INDEX A # OTHERWISE, SET NEWJOB TO THE RELATIVE 27777 CAF 0 -1 # ADDRESS OF THE NEW JOB'S CORE SET. 62747 AD -CCSPR 54067 TS NEWJOB 12521 TCF CHANJOB -2 01,3002 54132 EJ1 TS BUF +2 60131 AD BUF +1 # - OLD HIGH PRIORITY. 10000 CCS A 40132 CS BUF +2 13012 TCF EJ2 # NEW HIGH PRIORITY. 13010 NOOP 50002 INDEX Q 00002 TC 2 # PROCEED WITH SEARCH. 01,3012 54131 EJ2 TS BUF +1 00006 EXTEND 22130 QXCH BUF # FOR LOCATING CCS PRIORITY + X INSTR. 50130 INDEX BUF 00002 TC 2 # IDLING AND COMPUTER ACTIVITY (GREEN) LIGHT MAINTENANCE. THE IDLING ROUTINE IS NOT A JOB IN ITSELF, # BUT RATHER A SUBROUTINE OF THE EXECUTIVE. 1361 EBANK= SELFRET # SELF-CHECK STORAGE IN EBANK. F42">042928,000430: 01,3017 45030 DUMMYJOB CS ZERO # SET NEWJOB TO -0 FOR IDLING. 54067 TS NEWJOB 00003 RELINT 45025 CS TWO # TURN OFF THE ACTIVITY LIGHT. 00006 EXTEND 03011 WAND DSALMOUT /a>042934,000436: 01,3025 10067 ADVAN CCS NEWJOB # IS A NEWJOB ACTIVE? 12626 TCF NUCHANG2 # YES... ONE REQUIRING A CHANGE JOB. 35025 CAF TWO # NEW JOB ALREADY IN POSITION FOR 13036 TCF NUDIRECT # EXECUTION. 31361 CA SELFRET 54001 TS L # PUT RETURN ADDRESS IN L. 33035 CAF SELFBANK 15236 TCF SUPDXCHZ +1 # AND DISPATCH JOB. 1361 EBANK= SELFRET E4B">042945,000447: 01,3035 66102 SELFBANK BBCON SELFCHK 354">042947,000449: 01,3036 00006 NUDIRECT EXTEND # TURN THE GREEN LIGHT BACK ON. 05011 WOR DSALMOUT 52165 DXCH LOC # JOBS STARTED IN THIS FASHION MUST BE 15235 TCF SUPDXCHZ BLOCK 2 # IN FIXED-FIXED SO OTHERS MAY USE. COUNT* $$/EXEC # SUPDXCHZ - ROUTINE TO TRANSFER TO SUPERBANK. # CALLING SEQUENCE # TCF SUPDXCHZ WITH 2CADR OF DESIRED LOCATION IN A + L. 85A">042959,000461: 5235 56001 SUPDXCHZ XCH L # BASIC. 00006 +1 EXTEND 01007 WRITE SUPERBNK 54006 TS BBANK 00001 TC L >042965,000467: 5242 77677 NEG100 OCT 77677 Parent file is MAIN.agc