Assembly listing generated by yaYUL

Source Code

These source-code files are part of a reconstructed copy of Comanche 72, the first release of the Apollo Guidance Computer (AGC) Command Module (CM) software for Apollo 13.

They have been adapted from sources files created from a listing of Comanche 55. These source files were updated to match binary dumps of a set of Comanche 67 rope modules. They were then further modified by applying known changes between Comanche 67 and Comanche 72. A binary dump of module B2 of Comanche 72, part number 2010802-021, was also used to validate changes made to banks 05-13. 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 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.

021168,000002: 021169,000003: 021170,000004: 021171,000005: 021172,000006: 021173,000007: 021174,000008: 021175,000009: 021176,000010: 021177,000011: 021178,000012: 021179,000013: 021180,000014: 021181,000015: 021182,000016: 021183,000017: 021184,000018: 021185,000019: 021186,000020: 34,2002 021187,000021: 31,2000 021188,000022: 31,2000 021189,000023: 021190,000024: 31,2000 021191,000025: 021218,000052: 021219,000053: 31,2030 021220,000054: 31,2031 ## Copyright: Public domain. ## Filename: R31.agc ## Purpose: A section of Comanche revision 072. ## It is part of the reconstructed source code for the first ## 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 printout of Comanche 055, binary dumps of a set of ## Comanche 067 rope modules, and changelogs between Comanche 067 ## and 072. It has been adapted such that the resulting bugger words ## exactly match those specified for Comanche 072 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: 2024-05-13 MAS Created from Comanche 067. BANK 34 SETLOC R31 BANK COUNT* $$/R31 C">021192,000026: 31,2000 35073 R31CALL CAF PRIO3 05163 TC FINDVAC EBANK= SUBEXIT 02032 62064 2CADR V83CALL 159">021197,000031: 31,2004 35055 DSPDELAY CAF 1SEC 04676 TC BANKCALL 01732 CADR DELAYJOB 31044 CA EXTVBACT 75020 MASK BIT12 00006 EXTEND 12004 BZF DSPDELAY 8">021205,000039: 31,2013 30105 DISPN5X CA FLAGWRD9 # TEST R31FLAG (IN SUNDANCE R31FLAG WILL 75030 MASK BIT4 # ALWAYS BE SET AS R34 DOES NOT EXIST) 00006 EXTEND 12021 BZF +3 32136 CAF V16N54 # R31 USE NOUN 54 02022 TC +2 32137 CAF V16N53 # R34 USE NOUN 53 04676 TC BANKCALL 20561 CADR GOMARKF 05641 TC B5OFF 05641 TC B5OFF 12013 TCF DISPN5X 31,2027 06006 V83 TC INTPRET 77650 GOTO 62171 HAVEBASE # INTEG STATE VECTORS C">021221,000055: 31,2032 06006 V83CALL TC INTPRET 77650 GOTO 62140 STATEXTP # EXTRAPOLATE STATE VECTORS 350">021224,000058: 31,2035 52375 COMPDISP VLOAD VSU 00001 RATT 02327 RONE 51406 PUSH ABVAL # RATT-RONE TO 0D PD= 6 02321 STORE RANGE # METERS B-29 77301 NORM VLOAD 00047 X1 # RATT-RONE PD= 0 77762 VSR1 53457 VSL* UNIT 20201 0,1 52315 PDVL VSU # UNIT(LOS) TO 0D PD= 6 00007 VATT 02335 VONE 77641 DOT # (VATT-VONE).UNIT(LOS) PD= 0 77752 SL1 36323 STCALL RRATE # RANGE RATE M/CS B-7 47501 CDUTRIG # TO INITIALIZE FOR *NBSM* 77624 CALL 62311 R34LOS # NOTE. PDL MUST = 0. >021243,000077: 31,2060 53575 R34ANG VLOAD UNIT 02327 RONE 77715 PDVL # UR TO 0D PD= 6 15332 THISAXIS # UNITX FOR CM, UNITZ FOR LM 77214 BON VLOAD # CHK R31FLAG. ON=R31 THETA, OFF=R34 PHI 04713 R31FLAG 62070 +2 # R31-THETA 00015 12D 77624 CALL 47650 *NBSM* 41505 VXM PUSH # UXORZ TO 6D PD=12D 01736 REFSMMAT 72431 VPROJ VSL2 00001 0D 53445 BVSU UNIT 00007 6D 47315 PDVL VXV # UP/2 TO 12D PD=18D 02327 RONE 02335 VONE 47256 UNIT VXV 02327 RONE 63241 DOT PDVL # SIGN TO 12D, UP/2 TO MPAC PD=18D 00015 12D 50372 VSL1 DOT # UP.UXORZ 00007 6D 72565 SIGN SL1 00015 12D 77726 ACOS 26325 STOVL RTHETA 02327 RONE 51041 DOT BPL 00007 6D 62125 +5 44345 DLOAD BDSU # IF UXORZ.R NEG, RTHETA = 1 - RTHETA 02325 RTHETA 15342 DPPOSMAX 02325 STORE RTHETA # RTHETA BETWEEN 0 AND 1 REV. 77776 EXIT 35027 CAF BIT5 # HAVE WE BEEN ANSWERED 71044 MASK EXTVBACT 00006 EXTEND 15550 BZF ENDEXT # YES, DIE 41044 CS EXTVBACT 75020 MASK BIT12 27044 ADS EXTVBACT 12027 TCF V83 >021290,000124: 31,2136 04066 V16N54 VN 1654 >021291,000125: 31,2137 04065 V16N53 VN 1653 # STATEXTP DOES AN INITIAL PRECISION EXTRAPOLATION OF THE # LEM STATE VECTOR TO PRESENT TIME OR TO PIPTIME IF AV G # IS ON AND SAVES AS BASE VECTOR. IF AV G IS ON RN + VN # ARE USED AS THE CM STATE VECTOR AND THE INITIAL R RDOT # RTHETA ARE COMPUTED WITH NO FURTHER INTEGRATION. IF AV # G IS OFF A PRECISION EXTRAPOLATION IS MADE OF THE CM # STATE VECTOR TO PRESENT TIME AND..... # THE CM + LM STATE VECTORS ARE INTEGRATED TO PRES TIME # USING PRECISION OR CONIC AS SURFFLAG IS SET OR CLEAR. # IF AV G IS ON THEN SUBSEQUENT PASSES WILL PROVIDE # USE OF RN + VN AS CM STATE VECTOR AND THE LM STATE # VECTOR WILL BE PRECISION INTEGRATED USING LEMPREC # IF SURFFLAG IS SET. # CM STATE VECTOR RONE VONE + LM STATE VECTOR RATT # VATT ARE USED IN COMPUTING R RDOT RTHETA. 450">021313,000147: 31,2140 43034 STATEXTP RTB BOF # INITIAL INTEGRATION 45510 LOADTIME 03751 V37FLAG 62146 +3 # AV G OFF, USE PRES TIME 77624 CALL 62273 GETRVN # ON, USE RN VN PIPTIME 02343 STORE BASETIME # PRES TIME OR PIPTIME 34041 STCALL TDEC1 27114 LEMPREC 77775 VLOAD # BASE VECTOR, LM 00017 RATT1 26225 STOVL BASEOTP # POS. 00025 VATT1 02241 STORE BASEOTV # VEL. 71214 BON DLOAD 03711 V37FLAG 62035 COMPDISP # COMPUTE R RDOT RTHETA FROM # RONE(RN) VONE(VN) RATT+VATT(LEMPREC) 00015 TAT 34041 STCALL TDEC1 27100 CSMPREC 77775 VLOAD # BASE VECTOR, CM 00017 RATT1 26255 STOVL BASETHP # POS. 00025 VATT1 02263 STORE BASETHV # VEL. 345">021339,000173: 31,2171 47014 HAVEBASE BON RTB # SUBSEQUENT INTEGRATIONS 03711 V37FLAG 62256 GETRVN5 45510 LOADTIME 34041 STCALL TDEC1 # AV G OFF. SET INTEG. OF CM 27446 INTSTALL 43175 VLOAD CLEAR 02255 BASETHP 00263 MOONFLAG 25535 STOVL RCV 02263 BASETHV 15543 STODL VCV 02343 BASETIME 43014 BOF SET # GET APPROPRIATE MOONFLAG SETTING 04343 MOONTHIS 62212 +2 00063 MOONFLAG 77614 CLEAR 01673 INTYPFLG 43014 BON SET 04307 SURFFLAG 62220 +2 # PREC. IF LM DOWN 01473 INTYPFLG # CONIC IF LM NOT DOWN 35517 STCALL TET 27144 INTEGRVS # INTEGRATION --- AT LAST--- 77775 VLOAD 00001 RATT 26327 STOVL RONE 00007 VATT 16335 STODL VONE # GET SET FOR CONIC EXTRAP.,OTHER 00015 TAT 45014 BON CALL 04307 SURFFLAG 62267 GETRVN6 # LEMPREC IF LM DOWN 27446 INTSTALL # ..CONIC IF NOT DOWN 77614 SET 01473 INTYPFLG >021376,000210: 31,2236 00041 OTHINT STORE TDEC1 # ENTERED IF AV G ON TO INTEG LM 43175 VLOAD CLEAR 02225 BASEOTP 00263 MOONFLAG 25535 STOVL RCV 02241 BASEOTV 15543 STODL VCV 02343 BASETIME 43014 BOF SET 04343 MOONTHIS 62252 +2 00063 MOONFLAG 35517 STCALL TET 27144 INTEGRVS 77650 GOTO 62035 COMPDISP # COMPUTE R RDOT RTHETA 5">021392,000226: 31,2256 77624 GETRVN5 CALL # AV G ON 62273 GETRVN 45014 BON CALL 04307 SURFFLAG 62267 GETRVN6 # LM DOWN, LMPREC 27446 INTSTALL 52014 CLEAR GOTO 01673 INTYPFLG 62236 OTHINT 6">021401,000235: 31,2267 34041 GETRVN6 STCALL TDEC1 27114 LEMPREC 77650 GOTO 62035 COMPDISP # COMPUTE R RDOT RTHETA >021405,000239: 31,2273 77620 GETRVN STQ 00000 0D 52175 VLOAD GOTO # AV G ON, RONE = RN VONE = VN 01171 RN # AND USE PIPTIME 62300 +1 36327 STCALL RONE 62302 +1 52175 VLOAD GOTO 01177 VN 62305 +1 16335 STODL VONE 01205 PIPTIME 77650 GOTO 00000 0D SETLOC R34 BANK >021421,000255: 31,2311 77776 R34LOS EXIT 30036 CA CDUS 50120 INDEX FIXLOC 54011 TS 9D 30035 CA CDUT 50120 INDEX FIXLOC 54013 TS 11D 30120 CA FIXLOC 66211 AD SIX 40000 COM 50120 INDEX FIXLOC 54046 TS X1 06006 TC INTPRET 77624 CALL 46000 SXTNB 34015 STCALL 12D 62060 R34ANG Parent file is MAIN.agc