# Copyright: Public domain. # Filename: POWERED_FLIGHT_SUBROUTINES.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: 1259-1267 # Mod history: 2009-05-26 RSB Adapted from the corresponding # Luminary131 file, using page # images from Luminary 1A. # 2011-01-06 JL Fixed pseudo-label indentation. # # 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 1259 BANK 14 # SAME FBANK AS THE FINDCDUD SUB-PROGRAM SETLOC POWFLITE BANK EBANK= DEXDEX COUNT* $$/POWFL # CDUTRIG, CDUTRIG1, CDUTRIG2, AND CD*TR*GS ALL COMPUTE THE SINES AND # COSINES OF THREE 2'S COMPLEMENT ANGLES AND PLACE THE RESULT, DOUBLE # PRECISION, IN THE SAME ORDER AS THE INPUTS, AT SINCDU AND COSCDU. AN # ADDITIONAL OUTPUT IS THE 1'S COMPLEMENT ANGLES AT CDUSPOT. THESE # ROUTINES GO OUT OF THEIR WAY TO LEAVE THE MPAC AREA AS THEY FIND IT, # EXCEPT FOR THE GENERALLY UNIMPORTANT MPAC +2. THEY DIFFER ONLY IN # WHERE THEY GET THE ANGLES, AND IN METHOD OF CALLING. # # CDUTRIG (AND CDUTRIG1, WHICH CAN BE CALLED IN BASIC) COMPUTE THE # SINES AND COSINES FROM THE CURRENT CONTENTS OF THE CDU REGISTERS. # THE CONTENTS OF CDUTEMP, ETC., ARE NOT TOUCHED SO THAT THEY MAY # CONTINUE TO FORM A CONSISTENT SET WITH THE LATEST PIPA READINGS. # # CDUTRIG1 IS LIKE CDUTRIG EXCEPT THAT IT CAN BE CALLED IN BASIC. # # CD*TR*GS FINDS CDU VALUES IN CDUSPOT RATHER THAN IN CDUTEMP. THIS # ALLOWS USERS TO MAKE TRANSFORMATIONS USING ARBITRARY ANGLES, OR REAL # ANGLES IN AN ORDER OTHER THAN X Y Z. A CALL TO THIS ROUTINE IS # NECESSARY IN PREPARATION FOR A CALL TO AX*SR*T IN EITHER OF ITS TWO # MODES (SMNB OR NBSM). SINCE AX*SR*T EXPECTS TO FIND THE SINES AND # COSINES IN THE ORDER Y Z X THE ANGLES MUST HAVE BEEN PLACED IN CDUSPOT # IN THIS ORDER. CD*TR*GS NEED NOT BE REPEATED WHEN AX*SR*T IS CALLED # MORE THAN ONCE, PROVIDED THE ANGLES HAVE NOT CHANGED. NOTE THAT SINCE # IT CLOBBERS BUF2 (IN THE SINE AND COSINE ROUTINES) CD*TR*GS CANNOT BE # CALLED USING BANKCALL. SORRY. # # CD*TR*G IS LIKE CD*TR*GS EXCEPT THAT IT CAN BE CALLED IN # INTERPRETIVE. CDUTRIG EXIT TC CDUTRIGS TC INTPRET RVQ CD*TR*G EXIT TC CD*TR*GS TC INTPRET RVQ CDUTRIGS CA CDUX TS CDUSPOT +4 CA CDUY TS CDUSPOT # Page 1260 CA CDUZ TS CDUSPOT +2 CD*TR*GS EXTEND QXCH TEM2 CAF FOUR TR*GL**P MASK SIX # MAKE IT EVEN AND SMALLER TS TEM3 INDEX TEM3 CA CDUSPOT DXCH MPAC # STORING 2'S COMP ANGLE, LOADING MPAC DXCH VBUF +4 # STORING MPAC FOR LATER RESTORATION TC USPRCADR CADR CDULOGIC EXTEND DCA MPAC INDEX TEM3 DXCH CDUSPOT # STORING 1'S COMPLEMENT ANGLE TC USPRCADR CADR COSINE DXCH MPAC INDEX TEM3 DXCH COSCDU # STORING COSINE EXTEND INDEX TEM3 DCA CDUSPOT # LOADING 1'S COMPLEMENT ANGLE TC USPRCADR CADR SINE +1 # SINE +1 EXPECTS ARGUMENT IN A AND L DXCH VBUF +4 # BRINGING UP PRIOR MPAC TO BE RESTORED DXCH MPAC INDEX TEM3 DXCH SINCDU CCS TEM3 TCF TR*GL**P TC TEM2 # Page 1261 # ******************************************************************************************************* # QUICTRIG, INTENDED FOR GUIDANCE CYCLE USE WHERE TIME IS CRITICAL, IS A MUCH FASTER VERSION OF CD*TR*GS. # QUICTRIG COMPUTES AND STORES THE SINES AND COSINES OF THE 2'S COMPLEMENT ANGLES AT CDUSPOT, CDUSPOT +2, # AND CDUSPOT +4. UNLIKE CD*TR*GS, QUICTRIG DOES NOT LEAVE THE 1'S COMPLEMENT VERSIONS OF THE ANGLES IN # CDUSPOT. QUICTRIG'S EXECUTION TIME IS 4.1 MS; THIS IS 10 TIMES AS FAST AS CD*TR*GS. QUICTRIG MAY BE # CALLED FROM INTERPRETIVE AS AN RTB OP-CODE, OR FROM BASIC VIA BANKCALL OR IBNKCALL. QUICTRIG INHINT # INHINT SINCE DAP USES THE SAME TEMPS EXTEND QXCH ITEMP1 CAF FOUR +4 MASK SIX TS ITEMP2 INDEX ITEMP2 CA CDUSPOT TC SPSIN EXTEND MP BIT14 # SCALE DOWN TO MATCH INTERPRETER OUTPUTS INDEX ITEMP2 DXCH SINCDU INDEX ITEMP2 CA CDUSPOT TC SPCOS EXTEND MP BIT14 INDEX ITEMP2 DXCH COSCDU CCS ITEMP2 TCF QUICTRIG +4 CA ITEMP1 RELINT TC A # Page 1262 #**************************************************************************** # THESE INTERFACE ROUTINES MAKE IT POSSIBLE TO CALL AX*SR*T, ETC., IN # INTERPRETIVE. LATER, WHERE POSSIBLE, THEY WILL BE ELIMINATED. # # THESE INTERFACE ROUTINES ARE PERMANENT. ALL RESTORE USER'S EBANK # SETTING. ALL ARE STRICT INTERPRETIVE SUBROUTINES, CALLED USING "CALL", # RETURNING VIA QPRET. ALL EXPECT AND RETURN THE VECTOR TO BE TRANSFOR- # MED INTERPRETER-STYLE IN MPAC; COMPONENTS AT MPAC, MPAC +3, AND MPAC +5. # # TRG*SMNB AND TRG*NBSM BOTH EXPECT TO SEE THE 2'S COMPLEMENT ANGLES # AT CDUSPOT (ORDER Y Z X, AT CDUSPOT, CDUSPOT +2, AND CDUSPOT +4; ODD # LOCATIONS NEED NOT BE ZEROED). TRG*NBSM DOES THE NB TO SM TRANSFOR- # MATION; TRG*SMNB, VICE VERSA. # # CDU*NBSM DOES ITS TRANSFORMATION USING THE PRESENT CONTENTS OF # THE CDU COUNTERS. OTHERWISE IT IS LIKE TRG*NBSM. # # CDU*SMNB IS THE COMPLEMENT OF CDU*NBSM. CDU*SMNB EXIT TC CDUTRIGS TCF C*MM*N1 TRG*SMNB EXIT TC CD*TR*GS C*MM*N1 TC MPACVBUF # AX*SR*T EXPECTS VECTOR IN VBUF CS THREE # SIGNAL FOR SM TO NB TRANSFORMATION C*MM*N2 TC AX*SR*T TC INTPRET VLOAD RVQ VBUF CDU*NBSM EXIT TC CDUTRIGS TCF C*MM*N3 TRG*NBSM EXIT TC CD*TR*GS C*MM*N3 TC MPACVBUF # FOR AX*SR*T CA THREE # SIGNAL FOR NB TO SM TRANSFORMATION TCF C*MM*N2 # *NBSM* AND *SMNB* EXPECT TO SEE THE SINES AND COSINES (AT SINCDU # AND COSCDU) RATHER THAN THE ANGLES THEMSELVES. OTHERWISE THEY ARE # LIKE TRG*NBSM AND TRG*SMNB. # # NOTE THAT JUST AS CD*TR*GS NEED BE CALLED ONLY ONCE FOR EACH SERIES # OF TRANSFORMATIONS USING THE SAME ANGLES, SO TOO ONLY ONE OF TRG*NBSM # Page 1263 # AND TRG*SMNB NEED BE CALLED FOR EACH SERIES. FOR SUBSEQUENT TRANFOR- # MATIONS USE *NBSM* AND *SMNB*. *SMNB* EXIT TCF C*MM*N1 *NBSM* EXIT TCF C*MM*N3 # AX*SR*T COMBINES THE OLD SMNB AND NBSM. FOR THE NB TO SM # TRANSFORMATION, ENTER WITH +3 IN A. FOR SM TO NB, ENTER WITH -3. # THE VECTOR TO BE TRANSFORMED ARRIVES, AND IS RETURNED, IN VBUF. # AX*SR*T EXPECTS TO FIND THE SINES AND COSINES OF THE ANGLES OF ROTATION # AT SINCDU AND COSCDU, IN THE ORDER Y Z X. A CALL TO CD*TR*GS, WITH # THE 2'S COMPLEMENT ANGLES (ORDER Y Z X) AT CDUSPOT, WILL TAKE CARE OF # THIS. HERE IS A SAMPLE CALLING SEQUENCE:- # TC CDUTRIGS # CS THREE # ("CA THREE" FOR NBSM) # TC AX*SR*T # THE CALL TO CD*TR*GS NEED NOT BE REPEATED, WHEN AX*SR*T IS CALLED MORE # THAN ONCE, UNLESS THE ANGLES HAVE CHANGED. # # AX*SR*T IS GUARANTEED SAFE ONLY FOR VECTORS OF MAGNITUDE LESS THAN # UNITY. A LOOK AT THE CASE IN WHICH A VECTOR OF GREATER MAGNITUDE # HAPPENS TO LIE ALONG AN AXIS OF THE SYSTEM TO WHICH IT IS TO BE TRANS- # FORMED CONVINCES ONE THAT THIS IS A RESTRICTION WHICH MUST BE ACCEPTED. AX*SR*T TS DEXDEX # WHERE IT BECOMES THE INDEX OF INDEXES EXTEND QXCH RTNSAVER R*TL**P CCS DEXDEX # +3 --> 0 -3 --> 2 CS DEXDEX # THUS: +2 --> 1 -2 --> 1 AD THREE # +1 --> 2 -1 --> 0 EXTEND INDEX A DCA INDEXI DXCH DEXI CA ONE TS BUF EXTEND INDEX DEX1 DCS VBUF TCF LOOP1 # REALLY BE A SUBTRACT, AND VICE VERSA LOOP2 DXCH BUF # LOADING VECTOR COMPONENT, STORING INDEX # Page 1264 LOOP1 DXCH MPAC CA SINSLOC AD DEX1 TS ADDRWD TC DMPSUB # MULTIPLY AT SIN(CDUANGLE) CCS DEXDEX DXCH MPAC # NBSM CASE TCF +3 EXTEND # SMNB CASE DCS MPAC DXCH TERM1TMP CA SIX # SINCDU AND COSCDU (EACH 6 WORDS) MUST ADS ADDRWD # BE CONSECUTIVE AND IN THAT ORDER EXTEND INDEX BUF INDEX DEX1 DCA VBUF DXCH MPAC TC DMPSUB # MULTIPLY BY COS(CDUANGLE) DXCH MPAC DAS TERM1TMP DXCH TERM1TMP DDOUBL INDEX BUF INDEX DEX1 DXCH VBUF DXCH BUF # LOADING INDEX, STORING VECTOR COMPONENT CCS A # 'CAUSE THAT'S WHERE THE INDEX NOW IS TCF LOOP2 EXTEND DIM DEXDEX # DECREMENT MAGNITUDE PRESERVING SIGN TSTPOINT CCS DEXDEX # ONLY THE BRANCHING FUNCTION IS USED TCF R*TL**P TC RTNSAVER TCF R*TL**P TC RTNSAVER SINSLOC ADRES SINCDU # FOR USE IN SETTING ADDRWD INDEXI DEC 4 # ********** DON'T *********** DEC 2 # ********** TOUCH *********** DEC 0 # ********** THESE *********** # Page 1265 DEC 4 # ********** CONSTANTS *********** # ****************************************************************************** BANK 10 SETLOC FLESHLOC BANK COUNT* $$/POWFL # ROUTINE FLESHPOT COMPUTES THE BODY-STABLE MEMBER TRANSFORMATION MATRIX (COMMONLY CALLED XNB) AND STORES # IT IN THE LOCATIONS SPECIFIED BY THE ECADR ENTERING IN A. CALCSMSC EXIT TC BANKCALL CADR FLESHPOT -1 TC INTPRET RVQ XNBECADR ECADR XNB -1 CAF XNBECADR FLESHPOT TS TEM2 XCH EBANK XCH TEM2 MASK LOW8 AD OCT1400 TS TEM1 EXTEND DCA COSCDUY DXCH MPAC TC DMP ADRES COSCDUZ DXCH MPAC DDOUBL INDEX TEM1 DXCH 0 # = COSY COSZ EXTEND DCA SINCDUZ INDEX TEM1 DXCH 2 # = SINZ EXTEND DCS SINCDUY DXCH MPAC TC DMPSUB # ADDRWD SET TO COSCDUZ # Page 1266 DXCH MPAC DDOUBL INDEX TEM1 DXCH 4 # = - SINY COSZ EXTEND DCS SINCDUX DXCH MPAC TC DMPSUB # ADDRWD SET TO COSCDUZ STILL DXCH MPAC DDOUBL DXCH MPAC +3 EXTEND DCS SINCDUX DXCH MPAC TC DMP ADRES SINCDUZ EXTEND DCS MPAC DXCH MPAC +5 TC DMP ADRES SINCDUY DXCH MPAC DDOUBL DDOUBL DXCH MPAC +5 DXCH MPAC TC DMP ADRES COSCDUY DXCH MPAC DDOUBL DDOUBL DXCH BUF EXTEND DCA COSCDUY DXCH MPAC TC DMP ADRES COSCDUX DXCH MPAC DDOUBL DAS MPAC +5 EXTEND DCA SINCDUY DXCH MPAC TC DMPSUB # ADDRWD SET TO COSCDUX DXCH MPAC # Page 1267 DDOUBL DAS BUF DXCH BUF DXCH MPAC EXTEND DCA MPAC INDEX TEM1 DXCH 14 # = SINY COSX + SINX SINZ COSY EXTEND DCA MPAC +3 INDEX TEM1 DXCH 16 # = - SINX COSZ EXTEND DCA MPAC +5 INDEX TEM1 DXCH 20 # = COSX COSY - SINX SINY SINZ CA TEM1 TS ADDRWD EXTEND DCA Z AD FOUR DXCH LOC CAF BIT8 TS EDOP TCF VXV DXCH MPAC DDOUBL INDEX TEM1 DXCH 6 DXCH MPAC +3 DDOUBL INDEX TEM1 DXCH 10 DXCH MPAC +5 DDOUBL INDEX TEM1 DXCH 12 CA TEM2 TS EBANK TCF SWRETURN