perm filename REVINF[MAN,LCS] blob sn#141767 filedate 1974-02-21 generic text, type T, neo UTF8
00200	ARRAY D1(801),D2(901),D3(1011),D4(1123),D5(123),D6(43),D7(13);
00300	VARIABLE /R;
00500	REVINIT←1;R←0;
00600	COMPILE;
00700	INSTRUMENT REV;
00800	REV1(R,801,.827,D1);
00900	REV1(R,901,.805,D2);
01000	REV1(R,1011,.783,D3);
01100	REV1(R,1123,.764,D4);
01200	REV2(U1+U2+U3+U4,123,.7,D5);
01300	REV2(U5,43,.7,D6);
01400	REV2(U6,13,.7,D7);
01500	R←0;OUTA←OUTA+U7;OUTB←OUTB+U7;
01700	END;
01800	FINISH;
01900	
02000	<THE TOP LINE DECLARES THE ARRAYS TO BE USED.  THE RUN-TIME
02100	<VARIABLE R PICKS UP DATA FROM THE REGULAR INSTRUMENTS TO PASS
02200	<ON TO THE REV INSTRUMENT.  (THE SLASH IN FRONT OF THE
02300	<R MAHπS IT A RUN-TIME VARIABLE.  I.E. ITS VALUE MAY BE CHANGED
02400	<FROM SAMPLE TO SAMPLE - AS OPPOSED TO ORDINARY VARIABLES [NO
02500	<SLASH WHEN THEY ARE FIRST DECLARED] WHICH ARE FIXED EACH TIME THE
02600	<PARAMETERS FOR AN INSTRUMENT ARE READ IN.  HENCE THE VALUE OF R
02700	<WILL CHANGE FOR EACH SAMPLE.)  EACH TIME INSTRUMENT REV COMPUTES
02800	<A SAMPLE R IS SET BACK TO 0 (LINE 1300) SO THAT DATA FROM ONE
02900	<SAMPLE WILL NOT MIX WITH THAT FROM THE NEXT.  THE REV1 AND REV2
03000	<UNIT GENERATORS ARE ESSENTIALLY FEEDBACK LOOPS WITH DELAY TIMES
03100	<(IN SAMPLES) EQUAL TO THE FIRST NUMBER APPEARING IN THE PARENTHESES,
03200	<WITH THE SECOND NUMBER (LESS THAN 1) BEING THE MULTIPLIER (OR
03300	<GAIN) USED EACH TIME A SAMPLE MAKES THE LOOP.
03400	
03500	<   THE USUAL WAY TO USE REVERBERATION IS TO TAP THE OUTPUT OF
03600	<EACH INSTRUMENT, PUTTING A PERCENTAGE OF THE SIGNAL INTO R (USUALLY 
03700	<10 TO 20%).  THE RELATIONSHIP BETWEEN THE PERCENTAGE OF DIRECT
03800	<SIGNAL TO THE PERCENTAGE OF REVERBERATED SIGNAL SEEMS TO BE THE
03900	<THE MOST IMPORTANT ELEMENT IN GIVING THE ILLUSION OF VARYING
04000	<DISTANCES.
04100	
04200	<   IN THE FOLLOWING EXAMPLE IT WILL BE ASSUMED THAT 5 UNIT
04300	<GENERATORS INVOLVING 8 PARAMETERS ARE USED IN THE INSTRUMENT
04400	<PROPER.  THEN THE LAST LINES WOULD BE:
04500	
04600	<	R←R+U5*P8;
04700	<	OUTA←OUTA+U5*(1-P8);
04800	<	END;
04900	
05000	<   THUS P8 WILL HAVE THE PERCENTAGE OF THE SIGNAL TO BE
05100	<REVERBERATED.  IF STEREO IS USED THE FIRST LINE REQUIRES NO
05200	<CHANGES BUT THE REMAINING SIGNAL, AS INDICATED BY "*(1-P8)",
05300	<WILL BE SPLIT BETWEEN THE CHANNELS IN WHATEVER MANNER MAY
05400	<BE DESIRED.
05500	
05600	<   IN GENERAL THE REV INSTRUMENT SHOULD BE TURNED ON ONLY ONCE,
05700	<"PLAYING" ONE LONG "NOTE" FOR THE DURATION OF A PIECE.
05800	<IN THE FOLLOWING EXAMPLE THE ASSUMPTION IS THAT THE TOTAL
05900	<DURATION OF THE REGULAR NOTES IS 42".  REV PLAYS 2" LONGER TO
06000	<ALLOW THE REVERBATION TO DIE AWAY.
06100	
06200	<	REVINIT←1;R←0;
06300	<	PLAY;REV 0 42;
06400	<	--- [ALL THE NOTES FOLLOW] --
06500	<	FINISH;
06600	
06700	<   IF A LONGER WORK (SAY 2 1/2') IS TO BE DONE IN SECTIONS -- FOR
06800	<EVENTUALLY EITHER ONE LONG PLAY FROM THE COMPUTER OR FOR TAPE
06900	<SPLICING OF THE SEPARATE SECTIONS -- DO AS FOLLOWS:
07000	
07100	<	REVINIT←1;R←0;
07200	<	PLAY;REV 0 37.3;REVINIT←0;
07300	<	--- [THE NOTES FOR EXACTLY 37.3" FOLLOW] --
07400	<	FINISH;
07500	
07600	<   -- THEN, USING THE SAME CORE IMAGE (SO THE LAST STATE OF THE
07700	<REVERBERATOR WILL BE PRESERVED):
07800	
07900	<	PLAY;REV 0 78;
08000	<	--- [NOTES FOR EXACTLY 78"] --
08100	<	FINISH;
08200	
08300	<   -- THEN THE FINAL SECTION*
08400	
08500	<	PLAY;REV 0 37;
08600	<	--- [NOTES FOR THE LAST 34.7"] --
08700	<	FINISH;
08800	
08900	<  WHEN THESE THREE PARTS ARE PIECED TOGETHER THERE WILL BE NO
09000	<GAPS IN THE REVERBERATION, WHICH WILL EXTEND 2.3" BEYOND THE FINAL
09100	<NOTE.
09200	
09300	<  I AM NOT TOO SURE ABOUT THE FUNCTION OF REVINIT.  I BELIEVE IT
09400	<MUST BE SET BACK TO ZERO AFTER! THE FIRST PLAYING OF REV IF YOU
09500	<WISH TO HAVE THE REVERBERATION CARRY OVER FROM ONE PLAY;...FINISH;
09600	<INTO THE NEXT.