# Copyright: Public domain. # Filename: AOTMARK.agc # Purpose: Part of the source code for Luminary 1A build 099. # It is part of the source code for the Lunar Module's (LM) # Apollo Guidance Computer (AGC), for Apollo 11. # Assembler: yaYUL # Contact: Ron Burkey . # Website: www.ibiblio.org/apollo. # Pages: 244-261 # Mod history: 2009-05-10 SN (Sergio Navarro). Started adapting # from the Luminary131/ file of the same # name, using Luminary099 page images. # # This source code has been transcribed or otherwise adapted from # digitized images of a hardcopy from the MIT Museum. The digitization # was performed by Paul Fjeld, and arranged for by Deborah Douglas of # the Museum. Many thanks to both. The images (with suitable reduction # in storage size and consequent reduction in image quality as well) are # available online at www.ibiblio.org/apollo. If for some reason you # find that the images are illegible, contact me at info@sandroid.org # about getting access to the (much) higher-quality images which Paul # actually created. # # Notations on the hardcopy document read, in part: # # Assemble revision 001 of AGC program LMY99 by NASA 2021112-061 # 16:27 JULY 14, 1969 # Page 244 BANK 12 SETLOC AOTMARK1 BANK EBANK= XYMARK COUNT* $$/MARK AOTMARK INHINT CCS MARKSTAT # SEE IF AOTMARK BUSY TC +2 # MARK SYSTEM BUSY -- DO ALARM TC EXTVBCHK TC POODOO OCT 00105 EXTVBCHK CAF SIX # SEE IF EXT. VERB WORKING MASK EXTVBACT CCS A TCF MKABORT # YES -- ABORT CAF BIT2 # NO -- DISALLOW SOME EXTENDED VERB ACTION ADS EXTVBACT # BIT2 RESET IN ENDMARK MKVAC CCS VAC1USE # LOOK FOR A VAC AREAD -- DO ABORT IF TCF MKVACFND # NONE AVAILABLE CCS VAC2USE TCF MKVACFND CCS VAC3USE TCF MKVACFND CCS VAC4USE TCF MKVACFND CCS VAC5USE TCF MKVACFND DXCH BUF2 TC BAILOUT1 # ALL VAC AREAS OCCUPIED -- ABORT. OCT 01207 MKVACFND AD TWO TS MARKSTAT # STORE VAC ADR IN LOW 9 OF MARKSTAT CAF ZERO INDEX MARKSTAT TS 0 -1 # ZERO IN VACUSE REG TO SHOW VAC OCCUPIED CAF PRIO15 TC FINDVAC # SET UP JOB FOR GETDAT EBANK= XYMARK 2CADR GETDAT RELINT TCF SWRETURN # Page 245 MKABORT DXCH BUF2 TC BAILOUT1 # CONFLICT WITH EXTENDED VERB OCT 01211 MKRELEAS CAF ZERO XCH MARKSTAT # SET MARKSTAT TO ZERO MASK LOW9 # PICK UP VAC AREA AOR CCS A INDEX A TS 0 # SHOW MKVAC AREA AVAILABLE CAF ONE TC IBNKCALL CADR GOODEND # GO WAKE UP CALLING JOB # Page 246 KILLAOT CAF ZERO TS EXTVBACT # TERMINATE AOTMARK -- ALLOW EXT VERB TC GOTOPOOH GETDAT CS MARKSTAT # SET BIT12 TO DISCOURAGE MARKRUPT MASK BIT12 # BIT12 RESET AT GETMARK ADS MARKSTAT CAF V01N71 # DISPLAY DETENT AND STAR CODE TC BANKCALL CADR GOMARKF TCF KILLAOT # V34 -- DOES GOTOPOOH TCF DODAT # V33 -- PROCEED -- USE THIS STAR FOR MARKS ENTERDAT TCF GETDAT # ENTER -- REDISPLAY STAR CODE DODAT CAF HIGH9 # PICK DETENT CODE FROM BITS7-9 OF AOTCODE MASK AOTCODE # AND SEE IF CODE 1 TO 6 EXTEND MP BIT9 TS XYMARK # STORE DETENT EXTEND BZMF GETDAT # COAS CALIBRATION CODE - NO GOOD HERE AD NEG7 # SEE IF DETENT 7 FOR COAS EXTEND BZF CODE7 TCF CODE1TO6 CODE7 CAF V06N87* # CODE 7, COAS SIGHTING, GET OPTIC AXIS TC BANKCALL # AZ AND EL OF SIGHTING DEVICE FROM ASTRO CADR GOMARKF TCF KILLAOT # V34 -- DOES GOTOPOOH TCF +2 # PROCEED TCF CODE7 # ON ENTER, RECYCLE EXTEND DCA AZ # PICK UP AZ AND EL IN SP 25 COMP INDEX FIXLOC DXCH 8D # STORE IN 8D AND 9D OF LOCAL VAC CAF ZERO # BACKUP SYSTEM TO BE USED TCF COASCODE # ZERO APPARENT ROTATION CODE1TO6 INDEX XYMARK # INDEX AOT POSITION BY DET CODE CA AOTEL -1 INDEX FIXLOC TS 9D # STORE ELEVATION IN VAC+9D INDEX XYMARK # INDEX DET CODE 1,2 OR 3 # Page 247 CA AOTAZ -1 INDEX FIXLOC TS 8D # STORE AZIMUTH IN VAC +8D CA AOTAZ +1 # COMPENSATION FOR APPARENT ROTATION OF EXTEND # AOT FIELD OF VIEW IN LEFT AND RIGHT INDEX FIXLOC # DETENTS IS STORED IN VAC +10D IN SP MSU 8D # PRECISION ONE'S COMPLEMENT COASCODE INDEX FIXLOC TS 10D # ROT ANGLE TC INTPRET # COMPUTE X AND Y PLANE VECTORS # Page 248 # THE OPTAXIS SUBROUTINE COMPUTES THE X AND Y MARK PLANE VECS AND # ROTATES THEM THRU THE APPARENT FIELD OF VIEW ROTATION UNIQUE TO AOT # OPTAXIS USES OANB TO COMPUTE THE OPTIC AXIS # # INPUT -- AZIMUTH ANGLE IN SINGLE PREC AT CDU SCALE IN 8D OF JOB VAC # ELEVATION ANGLE IN SINGLE PREC AT CDU SCALE IN 9D OF JOB VAC # ROTATION ANGLE IN SINGLE PREC IS COMP SCALED BY PI IN 10D OF VAC # # OUTPUT -- OPTIC AXIS VEC IN NG COORDS IN SCAXIS # X-MARK PLANE 1/4VEC IN NB COORDS AT 18D OF JOB VAC # Y-MARK PLANE 1/4VEC IN NB COORDS AT 12D OF JOB VAC OPTAXIS CALL # GO COMPUTE OA AN X AND Y PLANE VECS OANB SLOAD SR1 # LOAD APP ROTATION IN ONES COMP 10D # RESCALE BY 2PI PUSH SIN # 1/2SIN(ROT) 0-1 PDDL COS PUSH VXSC # 1/2COS(ROT) 2-3 18D PDDL VXSC # 1/4COS(ROT)UYP 4-9 0 24D # 1/4SIN(ROT)UXP BVSU STADR # UP 4-9 STODL 12D # YPNB=1/4(COS(ROT)UYP-SIN(ROT)UXP) VXSC PDDL # UP 2-3 UP 0-1 FOR EXCHANGE 24D # 1/4COS(ROT)UXP PUSH 0-5 VXSC VAD # 1/4SIN(ROT)UYP 18D # UP 0-5 STADR STOVL 18D # XPNB=1/4(COS(ROT)UXP+SIN(ROT)UYP) LO6ZEROS # INITIALIZE AVE STAR VEC ACCUMULATOR STORE STARAD +6 EXIT TCF GETMKS # Page 249 # THE OANB SUBROUTINE COMPUTES THE OPTIC AXIS OF THE SIGHTING INSTRUMENT # FROM AZIMUTH AND ELEVATION INPUT FROM THE ASTRONAUT. # # INPUT -- AZIMUTH ANGLE IN SINGLE PREC 2'S COMP IN 8D OF JOB VAC # ELEVATION ANGLE IN SINGLE PREC 2'S COMP IN 9D OF VAC # # OUTPUT -- OPTIC AXIS IN NB COORDS. IN SCAXIS # X-PLANE 1/2VEC IN NB COORDS AT 24D OF VAC # Y-PLANE 1/2VEC IN NB COORDS AT 18D OF VAC BANK 05 SETLOC AOTMARK2 BANK COUNT* $$/MARK OANB SETPD STQ 0 GCTR # STORE RETURN SLOAD RTB 9D # PICK UP SP ELV CDULOGIC PUSH COS PDDL SIN # 1/2COS(ELV) PD 0-1 STADR STODL SCAXIS # OAX=1/2SIN(ELV) 8D RTB CDULOGIC PUSH COS STORE 20D # STORE UYP(Y) 20-21 PDDL SIN # 1/2COS(AZ) PD 2-3 PUSH DCOMP # PUSH 1/2S IN (AZ) 4-5 STODL 22D # STORE UYP(Z) 22-23 LO6ZEROS STODL 18D # STORE UYP(X) 18-19 DMP SL1 0 STODL SCAXIS +2 # OAY=1/2COS(ELV)SIN(AZ) DMP SL1 # UP 2-3 STADR # UP 0-1 STOVL SCAXIS +4 # OAZ=1/2COS(ELV)COS(AZ) 18D # LOAD UYP VEC VXV UNIT SCAXIS # UXP VEC=UYP X OA STORE 24D # STORE UXP GOTO GCTR # Page 250 # SURFSTAR COMPUTES A STAR VECTOR IN SM COORDINATES FOR LUNAR # SURFACE ALIGNMENT AND EXITS TO AVEIT TO AVERAGE STAR VECTORS. # # GIVEN X-MARK PLANE 1/4 VEC IN NB AT 18D OF LOCAL VAC # Y-MARK PLANE 1/4 VEC IN NB AT 12D OF LOCAL VAC # CURSOR SP 2COMP AT POSITION 1 OF INDEXED MARKVAC # SPIRAL SP 2COMP AT POSITION 3 OF INDEXED MARKVAC # CDUY,Z,X AT POSITIONS 0,2,4 OF INDEXED MARKVAC BANK 15 SETLOC P50S BANK COUNT* $$/R59 SURFSTAR VLOAD* 0,1 # PUT X-MARK CDUS IN CDUSPOT FOR TRG*NBSM STORE CDUSPOT SLOAD* RTB 1,1 # PICK UP YROT CDULOGIC STORE 24D # STORE CURSOR FOR SPIRAL COMP (REVS) BZE YZCHK # IF YROT ZERO -- SEE IF SROT ZERO JUSTZY PUSH COS PDDL SIN # 1/2COS(YROT) 0-1 VXSC PDDL # UP 0-1 1/8SIN(YROT)UXP 0-5 18D VXSC VSU # UP 0-5 12D # UYP UNIT VXV SCAXIS UNIT PUSH SLOAD* RTB 3,1 # PICK UP SPIRAL CDULOGIC STORE 26D # STORE SPIRAL (REVS) DSU DAD 24D ABOUTONE DMP DP1/12 STORE 26D # SEP=(360 + SPIRAL -CURSOR)/12 SIN VXSC # UP 0-5 VSL1 PDDL # 1/2SIN(SEP)(UPP X OA) 0-5 26D COS VXSC SCAXIS VSL1 VAD # UP 0-5 JUSTOA UNIT CALL TRG*NBSM STCALL 24D # STAR VEC IN SM AVEIT # GO AVERAGE # Page 251 ABOUTONE 2DEC .99999999 DP1/12 EQUALS DEG30 # .08333333 BANK 7 SETLOC AOTMARK1 BANK COUNT* $$/MARK YZCHK SLOAD* BZE # YROT ZERO AND IF SROT ZERO FORCE STAR 3,1 # ALONG OPTIC AXIS YSZERO DLOAD GOTO 24D JUSTZY # SROT NOT ZERO -- CONTINUE NORMALLY YSZERO VLOAD GOTO SCAXIS JUSTOA # Page 252 # THE GETMKS ROUTINE INITIALIZES THE SIGHTING MARK PROCEDURE GETMKS CAF ZERO # INITIALIZE MARK ID REGISTER AND MARK CNT TS XYMARK TS MARKCNTR CAF LOW9 # ZERO BITS10 TO 15 RETAINING MKVAC ADR MASK MARKSTAT TS MARKSTAT CAF MKVB54* # DISPLAY VB54 INITIALLY PASTIT TC BANKCALL CADR GOMARK4 TCF KILLAOT # V34 -- DOES GOTOPOOH TCF MARKCHEX # VB33 -- PROCEED, GOT MARKS, COMPUTE LOS TCF GETDAT # ENTER -- RECYCLE TO V01N71 MARKCHEX CS MARKSTAT # SET BIT12 TO DISCOURAGE MARKRUPT MASK BIT12 ADS MARKSTAT MASK LOW9 TS XYMARK # JAM MARK VAC ADR IN XYMARK FOR AVESTAR CAF ZERO TS MKDEX # SET MKDEX ZERO FOR LOS VEC CNTR CA MARKSTAT MASK PRIO3 # SEE IF LAST MK PART COMPLETE TS L CAF PRIO3 # BITS10 AND 11 EXTEND RXOR LCHAN EXTEND BZF AVESTAR # LAST PAIR COMPLETE -- TO COMPUTE LOS CNTCHK CCS MARKCNTR # NO PAIR SHOWING -- SEE IF PAIR IN HOLD TCF +2 # PAIR BURIED -- DECREMENT COUNTER TCF MKALARM # NO PAIR -- ALARM TS MARKCNTR # STORE DECREMENTED COUNTER AVESTAR CAF BIT12 # INITIALIZE MKDEX FOR STAR LOS COUNTER ADS MKDEX # MKDEX WAS INITIALIZED ZERO IN MARKCHEX CS MARKCNTR EXTEND MP SIX # GET C(L) = -6 MARKCNTR CS XYMARK AD L # ADD -- MARK VAC ADR SET IN MARKCHEX INDEX FIXLOC TS X1 # JAM -- CDU ADR OF X-MARK IN X1 CA FIXLOC # SET PD POINTER TO ZERO TS PUSHLOC TC INTPRET # Page 253 BON VLOAD* SURFFLAG # IF ON SURFACE COMPUTE VEC AT SURFSTAR SURFSTAR 1,1 # PUT Y-MARK CDUS IN CDUSPOT FOR TRG*NBSM STOVL CDUSPOT 12D # LOAD Y-PLANE VECTOR IN NG CALL TRG*NBSM # CONVERT IT TO STABLE MEMBER PUSH VLOAD* 0,1 # PUT X-MARK CDUS IN CDUSPOT FOR TRG*NBSM STOVL CDUSPOT 18D # LOAD X-PLANE VECTOR IN NB CALL TRG*NBSM # CONVERT IT TO STABLE-MEMBER VXV UNIT # UNIT(XPSM * YPSM) STADR STORE 24D AVEIT SLOAD PDVL # N(NUMBER OF VECS) IN 0-1 MKDEX 24D # LOAD CURRENT VECTOR VSR3 V/SC 0 STODL 24D # VEC/N 0 DSU DDV DP1/8 # (N-1)/N VXSC VAD STARAD +6 # ADD VEC TO PREVIOUSLY AVERAGED VECTOR 24D # (N-1)/N AVESTVEC + VEC/N STORE STARAD +6 # AVERAGE STAR VECTOR STORE STARSAV2 EXIT CCS MARKCNTR # SEE IF ANOTHER MARK PAIR IN MKVAC TCF AVESTAR -1 # THERE IS -- GO GET IT -- DECREMENT COUNTER ENDMARKS CAF FIVE # NO MORE MARKS -- TERMINATE AOTMARK INHINT TC WAITLIST EBANK= XYMARK 2CADR MKRELEAS TC ENDMARK MKALARM TC ALARM # NOT A PAIR TO PROCESS -- DO GETMKS OCT 111 TCF GETMKS V01N71 VN 171 V06N87* VN 687 # Page 254 # MARKRUPT IS ENTERED FROM INTERRUPT LEAD-INS AND PROCESSES CHANNEL 16 # CAUSED BY X,Y MARK OR MARK REJECT OR BY THE RATE OF DESCENT SWITCH MARKRUPT TS BANKRUPT CA CDUY # STORE CDUS AND TIME NOW -- THEN SEE IF TS ITEMP3 # WE NEED THEM CA CDUZ TS ITEMP4 CA CDUX TS ITEMP5 EXTEND DCA TIME2 DXCH ITEMP1 XCH Q TS QRUPT CAF OCT34 # SEE IF X OR Y MARK OR MKREJECT EXTEND RAND NAVKEYIN CCS A TCF +2 # ITS A LIVE ONE -- SEE IF ITS WANTED TCF SOMEKEY # ITS SOME OTHER KEY CAF BIT12 # ARE WE ASKING FOR A MARK MASK MARKSTAT CCS A TC RESUME # DON'T WANT MARK OR MKREJECT -- DO NOTHING CCS MARKSTAT # ARE MARKS BEING ACCEPTED TCF FINDKEY # THEY ARE -- WHICH ONE IS IT TC ALARM # MARKS NOT BEING ACCEPTED -- DO ALARM OCT 112 TC RESUME FINDKEY CAF BIT5 # SEE IF MARK REJECT. EXTEND RAND NAVKEYIN CCS A TCF MKREJ # IT'S A MARK REJECT CAF BIT4 # SEE IF Y MARK EXTEND RAND NAVKEYIN CCS A TCF YMKRUPT # IT'S A Y MARK CAF BIT3 # SEE IF X MARK EXTEND RAND NAVKEYIN # Page 255 CCS A TCF XMKRUPT # IT'S A X MARK SOMEKEY CAF OCT140 # NOT MARK OR MKREJECT -- SEE IF DESCENT BITS EXTEND RAND NAVKEYIN EXTEND BZF +3 # IF NO BITS TC POSTJUMP # IF DESCENT BITS CADR DESCBITS TC ALARM # NO INBITS IN CHANNEL 16. OCT 113 TC RESUME XMKRUPT CAF ZERO TS RUPTREG1 # SET X MARK STORE INDEX TO ZERO CAF BIT10 TCF +4 YMKRUPT CAF ONE TS RUPTREG1 # SET Y MARK STORE INDEX TO ONE CAF BIT11 TS XYMARK # SET MARK IDENTIFICATION TC MARKTYPE # SEE IF SURFACE MARK TCF SURFSTOR # SURFACE MARK -- JUST STORE CDUS CAF BIT14 # GOT A MARK -- SEE IF MARK PARI MADE MASK MARKSTAT EXTEND BZF VERIFYMK # NOT A PAIR, NORMAL PROCEDURE CS MARKCNTR # GO A PAIR, SEE IF ANOTHER CAN BE MADE AD FOUR # IF SO, INCREMENT POINTER, CLEAR BITS 10,11 EXTEND BZMF 5MKALARM # HAVE FIVE MARK PAIRS -- DON'T ALLOW MARK INCR MARKCNTR # OK FOR ANOTHER PAIR, INCR POINTER CS PRIO23 # CLEAR BITS 10,11,14 FOR NEXT PAIR MASK MARKSTAT TS MARKSTAT VERIFYMK CA XYMARK MASK MARKSTAT CCS A TCF +2 # THIS MARK NOT DESIRED TCF VACSTOR # MARK DESIRED -- STORE CDUS TC ALARM OCT 114 TC RESUME # RESUME -- DISPLAY UNCHANGED -- WAIT FOR ACTION # Page 256 5MKALARM TC ALARM # ATTEMPTING TO MAKE MORE THAN 5 MK PAIRS OCT 107 TC MARKTYPE # SEE IF SURFACE MARK TCF DSPV6N79 # IT IS TC RESUME # DON'T CHANGE DISPLAY -- DO NOTHING # Page 257 MKREJ TC MARKTYPE # SEE IF SURFACE TCF SURFREJ # SURFACE -- JUST CHECK MARK COUNTER CAF PRIO3 # INFLIGHT -- SEE IF MARKS MADE MASK MARKSTAT CCS A TCF REJECT # MARKS MADE -- REJECT ONE REJALM TC ALARM # NO MARK TO REJECT -- BAD PROCEDURE -- ALARM OCT 115 TC RESUME # DESIRED ACTION DISPLAYED REJECT CS PRIO30 # ZERO BIT14, SHOW REJ., SEE IF MARK SINCE MASK MARKSTAT # LAST REJECT AD BIT13 XCH MARKSTAT MASK BIT13 CCS A TCF REJECT2 # ANOTHER REJECT SET BIT 10+11 TO ZERO CS XYMARK # MARK MADE SINCE REJECT -- REJECT MARK IN 1D RENEWMK MASK MARKSTAT TS MARKSTAT TCF REMARK # GO REQUEST NEW MARK ACTION REJECT2 CS PRIO3 # ON SECOND REJECT -- DISPLAY VB53 AGAIN TCF RENEWMK SURFREJ CCS MARKCNTR # IF MARK DECREMENT COUNTER TCF +2 TCF REJALM # NO MARKS TO REJECT -- ALARM TS MARKCNTR TC RESUME # Page 258 # MARKTYPE TESTS TO SEE IF LEM ON LUNAR SURFACE. IF IT IS RETURN TO LOC+1 MARKTYPE CS FLAGWRD8 # SURFFLAG ******** TEMPORARY ****** MASK BIT8 CCS A INCR Q # IF SURFACE MARK RETURN TO LOC +1 TC Q # IF INFLIGHT MARK RETURN TO LOC +2 SURFSTOR CAF ZERO # FOR SURFACE MARK ZERO MARK KIND INDEX TS RUPTREG1 CS MARKSTAT # SET BITS10,11 TO SHOW SURFACE MARK MASK PRIO3 # FOR MARKCHEX ADS MARKSTAT VACSTOR CAF LOW9 MASK MARKSTAT # STORE MARK VAC ADR IN RUPTREG2 TS RUPTREG2 EXTEND DCA ITEMP1 # PICK UP MARKTIME DXCH TSIGHT # STORE LAST MARK TIME CA MARKCNTR # 6 X MARKCNTR FOR STORE INDEX EXTEND MP SIX XCH L # GET INDEX FROM LOW ORDER PART AD RUPTREG2 # SET CDU STORE INDEX TO MARKVAC ADS RUPTREG1 # INCREMENT VAC PICKUP BY MARK FOR FLIGHT TS MKDEX # STORE HERE IN CASE OF SURFACE MARK CA ITEMP3 INDEX RUPTREG1 TS 0 # STORE CDUY CA ITEMP4 INDEX RUPTREG1 TS 2 # STORE CDUZ CA ITEMP5 INDEX RUPTREG1 TS 4 # STORE CDUX TC MARKTYPE # IF SURFACE MARK -- JUST DO SURFJOB TCF SURFJOB CAF BIT13 # CLEAR BIT13 TO SHOW MARK MADE AD XYMARK # SET MARK ID IN MARKSTAT COM MASK MARKSTAT AD XYMARK TS MARKSTAT MASK PRIO3 # SEE IF X, Y MARK MADE TS L # Page 259 CA PRIO3 EXTEND RXOR LCHAN CCS A TCF REMARK # NOT PAIR YET, DISPLAY MARK ACTION CS MARKSTAT # MARK PAIR COMPLETE -- SET BIT14 MASK BIT14 ADS MARKSTAT TCF REMARK # GO DISPLAY V54 # Page 260 REMARK CAF PRIO3 # BITS 10 AND 11 MASK MARKSTAT EXTEND MP BIT6 # SHIFT MARK IDS TO BE 0 TO 3 FOR INDEX TS MKDEX # STORE VERB INDEX SURFJOB CAF PRIO15 TC NOVAC # ENTER JOB TO CHANGE DISPLAY TO EBANK= XYMARK # REQUEST NEXT ACTION 2CADR CHANGEVB TC RESUME CHANGEVB TC MARKTYPE TCF DSPV6N79 # SURFACE -- DISPLAY V 06 N 79 INDEX MKDEX # INFLIGHT -- PICK UP MARK VB INDEX CAF MKVB54 TC PASTIT # PASTE UP NEXT MK VERB DISPLAY # THE FOUR MKVBS ARE INDEXED -- THEIR ORDER CANNOT BE CHANGED MKVB54 VN 5471 # MAKE X OR Y MARK MKVB53 VN 5371 # MAKE Y MARK MKVB52 VN 5271 # MAKE X MARK MKVB54* VN 5471 # MAKE X OR Y MARK DP1/8 2DEC .125 OCT34 OCT 34 V06N71 VN 671 V06N79* VN 679 # Page 261 # ROUTINE TO REQUEST CURSOR AND SPIRAL MEASUREMENTS COUNT* $$/R59 DSPV6N79 CAF V06N79* # CURSOR -- SPIRAL DISPLAY TC BANKCALL CADR GOMARKF TCF KILLAOT # V34 -- DOES GOTOPOOH TCF SURFEND # V33 -- PROCEED, END MARKING CAF BIT6 # IF V32(OCT40) IN MPAC DO RECYCLE MASK MPAC # OTHERWISE IT IS LOAD VB ENTER SO CCS A # RE-DISPLAY V06N79 TCF SURFAGAN # VB32 -- RECYCLE TCF DSPV6N79 # ENTER SURFEND CS BIT14 # SET BIT14 TO SHOW MARK END MASK MARKSTAT AD BIT14 TS MARKSTAT SURFAGAN CA CURSOR INDEX MKDEX # HOLDS VAC AREA POINTER FOR SURF MARKING TS 1 # STORE CURSOR SP 2COMP CA SPIRAL INDEX MKDEX TS 3 # STORE SPIRAL CS MARKSTAT # IF BIT 14 SET -- END MARKING MASK BIT14 EXTEND BZF MARKCHEX CA MARKCNTR # THIS IS RECYCLE -- SEE IF 5 MARKS ALREADY AD ONE COM AD FIVE EXTEND BZMF 5MKALARM # CAN'T RECYCLE -- TOO MANY MARKS -- ALARM INCR MARKCNTR # OF FOR RECYCLE -- INCR COUNTER TCF GETMKS +3 # GO DISPLAY MARK VB