Assembly listing generated by yaYUL

Source Code

These source-code files are part of a reconstructed copy of Comanche 72/3 (AKA Manche72 revision 3), the final, flown mission release of the Apollo Guidance Computer (AGC) Command Module (CM) software for Apollo 13.

The starting point was the source code of Comanche 72 (itself previously reconstructed). Comanche 72 source code was then modified by incorporating changes known from contemporary documentation to have been made between revisions 72 and 72/3. The resulting code assembles to have identical memory-bank checksums as those specified in NASA drawing 2021153G; this gives reasonably high confidence that the changes that have been made are correct. In places where ambiguity exists, this ambiguity is discussed in "## Reconstruction:" comments.

Since no contemporary listings of Comanche 72/3 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.

050520,000002: 050521,000003: 050522,000004: 050523,000005: 050524,000006: 050525,000007: 050526,000008: 050527,000009: 050528,000010: 050529,000011: 050530,000012: 050531,000013: 050532,000014: 050533,000015: 050534,000016: 050535,000017: 050536,000018: 050537,000019: 5150 050538,000020: 050539,000021: 050540,000022: 050541,000023: 5150 050542,000024: < 050544,000026: 5151 050545,000027: 5152 050546,000028: 050547,000029: 5153 050548,000030: 5154 050549,000031: 5155 050550,000032: 5156 050551,000033: 5157 050552,000034: 5160 050553,000035: 5161 050554,000036: 5162 050555,000037: 050556,000038: 050557,000039: < 050572,000054: 5175 050573,000055: 5176 050574,000056: 5177 050575,000057: 050576,000058: 050577,000059: 050929,000411: 050930,000412: 01,3207 050931,000413: 01,3210 050932,000414: 01,3211 050933,000415: 01,3212 050934,000416: 01,3213 050935,000417: 01,3214 050936,000418: 01,3215 050937,000419: 050938,000420: 050939,000421: 01,3217 050940,000422: 01,3220 050941,000423: 01,3221 050942,000424: 01,3222 050943,000425: 050944,000426: 050945,000427: 050946,000428: 050947,000429: 01,3223 050948,000430: < 050956,000438: 01,3232 050957,000439: 01,3233 050958,000440: 01,3234 050959,000441: 050960,000442: 01,3235 050961,000443: 01,3236 050962,000444: 01,3237 050963,000445: 01,3240 050964,000446: 050965,000447: 01,3241 ## Copyright: Public domain. ## Filename: EXECUTIVE.agc ## Purpose: A section of Manche72 revision 3. ## It is part of the reconstructed source code for the final, flown ## release of the software for the Command Module's (CM) Apollo ## Guidance Computer (AGC) for Apollo 13. No original listings ## of this program are available; instead, this file was recreated ## from a reconstructed copy of Comanche 072. It has been adapted ## such that the resulting bugger words exactly match those ## specified for Manche72 revision 3 in NASA drawing 2021153G, ## which gives relatively high confidence that the reconstruction ## is correct. ## Assembler: yaYUL ## Contact: Ron Burkey <info@sandroid.org>. ## Website: www.ibiblio.org/apollo/index.html ## Mod history: 2024-05-19 MAS Created from Comanche 072. BLOCK 02 # TO ENTER A JOB REQUEST REQUIRING NO VAC AREA: COUNT 02/EXEC /a>050543,000025: 5150 00004 NOVAC INHINT 65242 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 35241 CAF EXECBANK 56004 XCH FBANK 54061 TS EXECTEM1 12650 TCF NOVAC2 # ENTER EXECUTIVE BANK. # TO ENTER A JOB REQUEST REQUIRING A VAC AREA - E.G., ALL (PARTIALLY) INTERPRETIVE JOBS. 3">050558,000040: 5163 00004 FINDVAC INHINT 54063 TS NEWPRIO 00006 EXTEND 50002 INDEX Q 30001 DCA 0 E">050563,000045: 5170 52066 SPVACIN DXCH NEWLOC 35241 CAF EXECBANK 56004 XCH FBANK 12626 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>050571,000053: 5174 56002 SPVAC XCH Q 67715 AD NEG2 56002 XCH Q 15170 TCF SPVACIN # TO SUSPEND A BASIC JOB SO A HIGHER PRIORITY JOB MAY BE SERVICED: >050578,000060: 5200 22002 CHANG1 LXCH Q 35241 CAF EXECBANK 56006 XCH BBANK 12727 TCF CHANJOB # TO SUSPEND AN INTERPRETIVE JOB: >050585,000067: 5204 40164 CHANG2 CS LOC # NEGATIVE LOC SHOWS JOB = INTERPRETIVE. # ITRACE (4) REFERS TO "CHANG2". 54001 TS L 35241 +2 CAF EXECBANK 54006 TS BBANK 12726 TCF CHANJOB -1 # TO VOLUNTARILY SUSPEND A JOB UNTIL THE COMPLETION OF SOME ANTICIPATED EVENT (I/O EVENT ETC.): 550">050594,000076: 5211 54164 JOBSLEEP TS LOC 35241 CAF EXECBANK 54004 TS FBANK 13017 TCF JOBSLP1 # TO AWAKEN A JOB PUT TO SLEEP IN THE ABOVE FASHION: 5">050601,000083: 5215 00004 JOBWAKE INHINT 54065 TS NEWLOC 45032 CS TWO # EXIT IS VIA FINDVAC/NOVAC PROCEDURES. 26002 ADS Q 35241 CAF EXECBANK 56004 XCH FBANK 13044 TCF JOBWAKE2 # TO CHANGE THE PRIORITY OF A JOB CURRENTLY UNDER EXECUTION: E47">050611,000093: 5224 00004 PRIOCHNG INHINT # NEW PRIORITY ARRIVES IN A. RETURNS TO 54063 TS NEWPRIO # CALLER AS SOON AS NEW JOB PRIORITY IS 35241 CAF EXECBANK # HIGHEST. PREPARE FOR POSSIBLE BASIC- 56006 XCH BBANK # STYLE CHANGE-JOB. 54165 TS BANKSET 30002 CA Q 13113 TCF PRIOCH2 # TO REMOVE A JOB FROM EXECUTIVE CONSIDERATIONS: F42">050621,000103: 5233 35241 ENDOFJOB CAF EXECBANK 54004 TS FBANK 13124 TCF ENDJOB1 4">050625,000107: 5236 30061 ENDFIND CA EXECTEM1 # RETURN TO CALLER AFTER JOB ENTRY 54004 TS FBANK # COMPLETE. 16710 TCF Q+2 E4B">050628,000110: 5241 02626 EXECBANK CADR FINDVAC2 554">050630,000112: 5242 00110 FAKEPRET ADRES MPAC -36D # LOC(MPAC +6) - LOC(QPRET) # LOCATE AN AVAILABLE VAC AREA. BANK 01 COUNT 01/EXEC 332">050637,000119: 01,2626 54061 FINDVAC2 TS EXECTEM1 # (SAVE CALLER'S BANK FIRST.) 10400 CCS VAC1USE 12643 TCF VACFOUND 10454 CCS VAC2USE 12643 TCF VACFOUND 10530 CCS VAC3USE 12643 TCF VACFOUND 10604 CCS VAC4USE 12643 TCF VACFOUND 10660 CCS VAC5USE 12643 TCF VACFOUND 07755 TC BAILOUT 31201 OCT 31201 # NO VAC AREAS E44">050651,000133: 01,2643 65032 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 >050657,000139: 01,2650 35035 NOVAC2 CAF ZERO # NOVAC ENTERS HERE. FIND A CORE SET. 54064 TS LOCCTR 32657 CAF NO.CORES # SEVEN SETS OF ELEVEN REGISTERS EACH. >050660,000142: 01,2653 54062 NOVAC3 TS EXECTEM2 50064 INDEX LOCCTR 10167 CCS PRIORITY # EACH PRIORITY REGISTER CONTAINS -0 IF 12717 TCF NEXTCORE # THE CORRESPONDING CORE SET IS AVAILABLE. 553">050664,000146: 01,2657 00006 NO.CORES DEC 6 B-14 12717 TCF NEXTCORE # AN ACTIVE JOB HAS A POSITIVE PRIORITY # BUT A DORMANT JOB'S PRIORITY IS NEGATIVE E44">050668,000150: 01,2661 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 75062 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 12704 TCF SETLOC # OVFIND AND FIXLOC IMMEDIATELY. 54121 TS OVFIND 30166 CA PUSHLOC 54120 TS FIXLOC 354">050681,000163: 01,2674 10067 SPECTEST CCS NEWJOB # SEE IF ANY ACTIVE JOBS WAITING (RARE). 12704 TCF SETLOC # MUST BE AWAKENED BUT UNCHANGED JOB. 05753 TC CCSHOLE 05753 TC CCSHOLE 54067 TS NEWJOB # +0 SHOWS ACTIVE JOB ALREADY SET. 52066 DXCH NEWLOC 52165 DXCH LOC 15236 TCF ENDFIND >050690,000172: 01,2704 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. 65236 BZMF ENDFIND 30064 CA LOCCTR # LOCCTR IS LEFT SET AT THIS CORE SET IF 54067 TS NEWJOB # THE CALLER WANTS TO LOAD ANY MPAC 15236 TCF ENDFIND # REGISTERS, ETC. 245">050702,000184: 01,2717 33054 NEXTCORE CAF COREINC 26064 ADS LOCCTR 10062 CCS EXECTEM2 12653 TCF NOVAC3 07755 TC BAILOUT # NO CORE SETS. 31202 OCT 31202 # 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">050712,000194: 01,2727 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 35035 CAF ZERO 56121 XCH OVFIND # MAKE PUSHLOC NEGATIVE IF OVFIND NZ. 00006 EXTEND 12767 BZF +3 40166 CS PUSHLOC 54166 TS PUSHLOC 52167 DXCH PUSHLOC 50067 INDEX NEWJOB 52167 DXCH PUSHLOC 52167 DXCH PUSHLOC # SWAPS PUSHLOC AND PRIORITY. 35062 CAF LOW9 # SET FIXLOC TO BASE OF VAC AREA. 70167 MASK PRIORITY 54120 TS FIXLOC 10166 CCS PUSHLOC # SET OVERFLOW INDICATOR ACCORDING TO 35035 CAF ZERO 13005 TCF ENDPRCHG -1 40166 CS PUSHLOC 54166 TS PUSHLOC 35033 CAF ONE 56121 XCH OVFIND 54067 TS NEWJOB 847">050765,000247: 01,3006 00003 ENDPRCHG RELINT 52165 DXCH LOC # BASIC JOBS HAVE POSITIVE ADDRESSES, SO 00006 EXTEND # DISPATCH WITH A DTCB. 63013 BZMF +2 # IF INTERPRETIVE, SET UP EBANK, ETC. 52006 DTCB 40000 COM # EPILOGUE TO JOB CHANGE FOR INTERPRETIVE 65033 AD ONE 54164 TS LOC # RESUME. 16017 TCF INTRSM # COMPLETE JOBSLEEP PREPARATIONS. 1">050777,000259: 01,3017 00004 JOBSLP1 INHINT 40167 CS PRIORITY # NNZ PRIORITY SHOWS JOB ASLEEP. 54167 TS PRIORITY 36043 CAF LOW7 70006 MASK BBANK 00006 EXTEND 04007 ROR SUPERBNK # SAVE OLD SUPERBANK VALUE. 54165 TS BANKSET 45035 CS ZERO 2">050786,000268: 01,3030 54131 JOBSLP2 TS BUF +1 # HOLDS - HIGHEST PRIORITY. 13141 TCF EJSCAN # SCAN FOR HIGHEST PRIORITY ALA ENDOFJOB. 732">050789,000271: 01,3032 00004 NUCHANG2 INHINT # QUICK... DONT LET NEWJOB CHANGE TO +0. 10067 CCS NEWJOB 13037 TCF +3 # NEWJOB STILL PNZ 00003 RELINT # NEW JOB HAS CHANGED TO +0. WAKE UP JOB 13233 TCF ADVAN +2 # VIA NUDIRECT. (VERY RARE CASE.) 35032 CAF TWO 00006 EXTEND 05011 WOR DSALMOUT # TURN ON ACTIVITY LIGHT 52165 DXCH LOC # AND SAVE ADDRESS INFO FOR BENEFIT OF 12733 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">050805,000287: 01,3044 54061 JOBWAKE2 TS EXECTEM1 35035 CAF ZERO # BEGIN CORE SET SCAN. 54064 TS LOCCTR 32657 CAF NO.CORES 534">050809,000291: 01,3050 54062 JOBWAKE4 TS EXECTEM2 50064 INDEX LOCCTR 10167 CCS PRIORITY 13056 TCF JOBWAKE3 # ACTIVE JOB - CHECK NEXT CORE SET. 3">050813,000295: 01,3054 00014 COREINC DEC 12 B-14 # 12 REGISTERS PER CORE SET. 13065 TCF WAKETEST # SLEEPING JOB - SEE IF CADR MATCHES. 533">050816,000298: 01,3056 33054 JOBWAKE3 CAF COREINC 26064 ADS LOCCTR 10062 CCS EXECTEM2 13050 TCF JOBWAKE4 45033 CS ONE # EXIT IF SLEEPING JOB NOT FOUND. 54064 TS LOCCTR 15236 TCF ENDFIND 354">050824,000306: 01,3065 40065 WAKETEST CS NEWLOC 50064 INDEX LOCCTR 60164 AD LOC 00006 EXTEND 13073 BZF +2 # IF MATCH. 13056 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 44364 CS FBANKMSK # MAKE UP THE 2CADR OF THE WAKE ADDRESS 70065 MASK NEWLOC # USING THE CADR IN NEWLOC AND THE EBANK 65021 AD 2K # HALF OF BBANK SAVED IN BANKSET. 56065 XCH NEWLOC 74364 MASK FBANKMSK 50064 INDEX LOCCTR 60165 AD BANKSET 54066 TS NEWLOC +1 10064 CCS LOCCTR # SPECIAL TREATMENT IF THIS JOB WAS 12704 TCF SETLOC # ALREADY IN THE RUN (0) POSITION. 12674 TCF SPECTEST # PRIORITY CHANGE. CHANGE THE CONTENTS OF PRIORITY AND SCAN FOR THE JOB OF HIGHEST PRIORITY. 2">050852,000334: 01,3113 54164 PRIOCH2 TS LOC 35035 CAF ZERO # SET FLAG TO TELL ENDJOB SCANNER IF THIS 54130 TS BUF # JOB IS STILL HIGHEST PRIORITY. 35062 CAF LOW9 70167 MASK PRIORITY 60063 AD NEWPRIO 54167 TS PRIORITY 40000 COM 13030 TCF JOBSLP2 # AND TO EJSCAN. # RELEASE THIS CORE SET AND VAC AREA AND SCAN FOR THE JOB OF HIGHEST ACTIVE PRIORITY. 1">050864,000346: 01,3124 00004 ENDJOB1 INHINT 45035 CS ZERO 54131 TS BUF +1 56167 XCH PRIORITY 75062 MASK LOW9 54001 TS L 45242 CS FAKEPRET 60001 AD L 00006 EXTEND 63141 BZMF EJSCAN # NOVAC ENDOFJOB 10001 CCS L 50000 INDEX A 54000 TS 0 >050881,000363: 01,3141 10203 EJSCAN CCS PRIORITY +12D 03206 TC EJ1 05753 TC CCSHOLE 13145 TCF +1 10217 CCS PRIORITY +24D # EXAMINE EACH PRIORITY REGISTER TO FIND 03206 TC EJ1 # THE JOB OF HIGHEST ACTIVE PRIORITY. 05753 TC CCSHOLE 13151 TCF +1 10233 CCS PRIORITY +36D 03206 TC EJ1 >050893,000375: 01,3153 67610 -CCSPR -CCS PRIORITY 13155 TCF +1 10247 CCS PRIORITY +48D 03206 TC EJ1 05753 TC CCSHOLE 13161 TCF +1 10263 CCS PRIORITY +60D 03206 TC EJ1 05753 TC CCSHOLE 13165 TCF +1 10277 CCS PRIORITY +72D 03206 TC EJ1 05753 TC CCSHOLE 13171 TCF +1 # EVALUATE THE RESULTS OF THE SCAN. 10131 CCS BUF +1 # SEE IF THERE ARE ANY ACTIVE JOBS WAITING 05753 TC CCSHOLE 05753 TC CCSHOLE 13176 TCF +2 13223 TCF DUMMYJOB 10130 CCS BUF # BUF IS ZERO IF THIS IS A PRIOCHNG AND 13201 TCF +2 # CHANGED PRIORITY IS STILL HIGHEST. 13005 TCF ENDPRCHG -1 50000 INDEX A # OTHERWISE, SET NEWJOB TO THE RELATIVE 27777 CAF 0 -1 # ADDRESS OF THE NEW JOB'S CORE SET. 63153 AD -CCSPR 54067 TS NEWJOB 12725 TCF CHANJOB -2 01,3206 54132 EJ1 TS BUF +2 60131 AD BUF +1 # - OLD HIGH PRIORITY. 10000 CCS A 40132 CS BUF +2 13216 TCF EJ2 # NEW HIGH PRIORITY. 13214 NOOP 50002 INDEX Q 00002 TC 2 # PROCEED WITH SEARCH. 01,3216 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">050949,000431: 01,3223 45035 DUMMYJOB CS ZERO # SET NEWJOB TO -0 FOR IDLING. 54067 TS NEWJOB 00003 RELINT 45032 CS TWO # TURN OFF THE ACTIVITY LIGHT. 00006 EXTEND 03011 WAND DSALMOUT /a>050955,000437: 01,3231 10067 ADVAN CCS NEWJOB # IS A NEWJOB ACTIVE? 13032 TCF NUCHANG2 # YES... ONE REQUIRING A CHANGE JOB. 35032 CAF TWO # NEW JOB ALREADY IN POSITION FOR 13242 TCF NUDIRECT # EXECUTION. 31361 CA SELFRET 54001 TS L # PUT RETURN ADDRESS IN L. 33241 CAF SELFBANK 15244 TCF SUPDXCHZ +1 # AND DISPATCH JOB. 1361 EBANK= SELFRET E4B">050966,000448: 01,3241 66102 SELFBANK BBCON SELFCHK 354">050968,000450: 01,3242 00006 NUDIRECT EXTEND # TURN THE GREEN LIGHT BACK ON. 05011 WOR DSALMOUT 52165 DXCH LOC # JOBS STARTED IN THIS FASHION MUST BE 15243 TCF SUPDXCHZ BLOCK 2 # IN FIXED-FIXED SO OTHERS MAY USE. COUNT 02/EXEC # SUPDXCHZ - ROUTINE TO TRANSFER TO SUPERBANK. # CALLING SEQUENCE # TCF SUPDXCHZ WITH 2CADR OF DESIRED LOCATION IN A + L. 85A">050981,000463: 5243 56001 SUPDXCHZ XCH L # BASIC. 00006 +1 EXTEND 01007 WRITE SUPERBNK 54006 TS BBANK 00001 TC L >050987,000469: 5250 77677 NEG100 OCT 77677 Parent file is MAIN.agc